belt winding device

Abstract

Belt winding device (10) with: a spool (20) on which a belt fitted by an occupant is wound; a motor (38) having a rotating shaft (242) and an engaging section (58A) arranged coaxially to the rotating shaft (242); a first gear (40) which is fixed to the rotating shaft (242); a second gear (46) which meshes with the first gear (40) and which is rotated by the rotation of the first gear (40) so that the coil (20) is rotated; and a housing (52) having a support section (264) for the second gear (46) on which the second gear (46) is supported, and an engagement section (270) which engages with the engaging section (58A) such that there is a fastening tolerance between the engagement section (270) and the engaging section (58A), wherein the motor (38) is fixed to the housing (52) in a state in which the engaging section (58A) engages with the engagement section (270). wherein the engagement section (270) is an engagement hole, wherein a projection (268) is provided on an inner circumferential section of the engagement hole; and the projection (268) is deformed in a state in which the engaging section (58A) is positioned inside the engagement hole.

Description

BACKGROUND OF THE STATE OF TECHNOLOGY Field of the invention

[0001] The present invention relates to a belt winding device. Relevant state of the art

[0002] The disclosed Japanese patent application JP 2007-099257 A describes a belt winding device that is capable of winding a belt onto a spool by rotating the spool in a winding direction by the driving force of a motor.

[0003] US 2005 001 23 20 A1 discloses a vehicle seat belt device comprising a spool, a motor for rotating the spool to control the belt tension of a seat belt, and a housing frame in which the spool is arranged. The motor is attached to one side of the housing frame by means of a motor mount.

[0004] In belt winding devices that rotate a spool by means of a motor's driving force, it is desirable to reduce operating noise when the spool is rotated by the motor's driving force. SUMMARY

[0005] In view of the circumstances explained above, it is an object of the invention to create a belt winding device that is capable of reducing operating noise when a spool is rotated by a driving force of a motor.

[0006] This problem is solved by a belt winding device with the features of claim 1. Advantageous further developments are shown in the dependent claims.

[0007] A belt winding device according to claim 1 has: a spool on which a belt fitted by an occupant is wound; a motor having a rotating shaft and an engaging section arranged coaxially to the rotating shaft; a first gear fixed to the rotating shaft; a second gear meshing with the first gear, which is rotated by the rotation of the first gear such that the spool is rotated;and a housing having a support section for the second gear, on which the second gear is supported, and an engagement section which engages with the engaging section such that a mounting tolerance exists between the engagement section and the engaging section, wherein the motor is fixed to the housing in a state in which the engaging section is engaged with the engagement section, wherein: the engagement section is an engagement hole, having a projection on an inner circumferential section of the engagement hole; and the projection deforms in a state in which the engaging section is arranged inside the engagement hole.

[0008] A belt winding device according to claim 2 is the belt winding device according to claim 1, wherein the engaging section abuts a section of an inner circumferential surface of the engagement hole, wherein the projection is not formed on the section of the inner circumferential surface.

[0009] According to the belt winding device of claim 1, the belt, which is fitted by an occupant, is wound onto the spool. When the motor's rotating shaft turns, the first gear, fixed to the rotating shaft, is turned. Furthermore, as the first gear turns, the second gear, which meshes with the first gear, is also turned, and the spool is turned. This allows the belt to be wound onto the spool.

[0010] The second gear is supported on the second gear support section of the housing. The motor, to whose rotating shaft the first gear is fixed, is fixed to the housing. It should be noted that, in the first aspect, the section that engages coaxially with the rotating shaft of the motor is in such a way that a mounting tolerance exists between them. Accordingly, by designing such a structure, in which the engaging section of the motor engages with the engaging section of the housing in such a way that a mounting tolerance exists between them, variation in the separation between the rotating shaft of the first gear (the rotating shaft of the motor) and the rotating shaft of the second gear can be suppressed.The first gear and the second gear are therefore stably meshed, which allows for a reduction in operating noise when the coil is rotated under the driving force of the motor.

[0011] According to the belt winding device of claim 1, the projection provided on the inner circumferential section of the engagement hole is deformed when the engaging section of the motor is inserted into the engagement hole of the housing. Because the projection provided on the inner circumferential section of the engagement hole is deformed when the engaging section of the motor is inserted into the engagement hole of the housing in this manner, the engaging section of the motor can easily engage with the engagement hole of the housing in a state where the required mounting tolerance exists between them.

[0012] According to the belt winding device of claim 2, in a state where the engaging section of the motor has been inserted into the engagement hole of the housing, the engaging section of the motor rests against the portion of the inner circumferential surface of the engagement hole of the housing where the projection is not formed. Accordingly, by designing such a structure in which the engaging section of the motor rests against a portion of the inner circumferential surface of the engagement hole of the housing that is not deformed, variation in the separation between the rotating shaft of the first gear (rotating shaft of the motor) and the rotating shaft of the second gear can be avoided even more effectively.

[0013] On the other hand, according to claim 1, it is possible that the section coming into engagement only rests against a deformed section of the projection. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Examples of implementation are described in detail below with reference to the attached drawings. Fig. Figure 1 shows a perspective exploded view of a belt winding device according to an exemplary embodiment. Fig. Figure 2 shows a side view of a first coupling viewed from the side of a foot of a frame, showing a state in which a locking bar is engaged with a ratchet wheel (locking wheel). Fig. 3 shows a Fig. 2. Corresponding side view of the first coupling viewed from the side of the base of the frame, showing a state in which the locking bar is not engaged with the ratchet wheel. Fig. Figure 4 shows a perspective exploded view of a second coupling. Fig. Figure 5 shows a perspective exploded view of a second coupling from the perspective of the Fig. 4 opposite sides. Fig. Figure 6 shows a cross-sectional view along an axial direction of a second coupling. The Fig. 7A and Fig. Figure 7B shows a section-like construction of a second coupling. Fig. Figure 7A shows a side view of a clutch spring in its normal state, and Fig. Figure 7B shows a side view of a condition in which an outside diameter dimension of a spiral section of the clutch spring is enlarged. Fig. Figure 8 shows a schematic side view of an engine. Fig. Figure 9 shows an enlarged top view of the immediate surroundings of a motor fixing section in which a motor is fixed to an operating housing. Fig. Figure 10 shows an explanatory illustration to explain a first transmission route of a rotation of a motor's rotating shaft during a fitting support and during a pre-tensioning. Fig. Figure 11 shows an explanatory illustration to explain a second transmission route of a rotation of a rotating shaft of a motor during a winding support. Fig. Figure 12 shows a cross-sectional view of an access hole fitted with a flexible strip. Fig. Figure 13 shows a schematic top view of an access hole and its immediate surroundings in a modified example. Fig. 14 shows a Fig. 13. A corresponding schematic top view of an access hole and its immediate surroundings in a further modified example. DETAILED DESCRIPTION

[0015] Below is a belt winding device of an exemplary embodiment with reference to the Fig. 1, Fig. 2, Fig. 3, Fig. 4, Fig. 5, Fig. 6, Fig. 7, Fig. 8 to Fig. 9 explained.

[0016] Fig. Figure 1 shows a perspective exploded view of a belt winding device 10 according to an embodiment of the present invention. As shown in Fig. As shown in Figure 1, the belt winding device 10 has a frame 12. The frame 12 has a substantially plate-shaped back plate 14. The back plate (rear plate) 14 is fixed to a vehicle body by a fastening element, such as a screw (not shown in the drawing), thereby fixing the belt winding device 10 to the vehicle body. A pair of parallel feet 16, 18 extend from both lateral ends of the back plate 14, and a spool 20, produced by molding or the like, is rotatably arranged between the feet 16, 18. It should be noted that a connecting piece 32 spans (bridges) between the feet 16 and 18.

[0017] The spool 20 is formed in a substantially circular cylindrical shape (tubular shape). A base end section of a belt, formed into an elongated strip shape (not shown in the drawings), is fixed to the spool 20. Rotating the spool 20 in one direction about its axis (hereinafter referred to as the "winding direction") causes the belt to wind onto an outer circumferential section of the spool 20 in a layer-by-layer fashion, starting from a base end of the belt. Pulling the belt from its guide end pulls out the belt that has been wound onto the outer circumferential section of the spool 20, accompanied by a rotation of the spool 20 in the opposite direction to the rotation direction during winding of the belt (the rotation direction of the spool 20 during the withdrawal of the belt is hereinafter referred to as the "withdrawal direction").

[0018] A support shaft section 29 projects from an axial central section of an end section on the side of the base 16 of the coil 20. The support shaft section 29 emerges substantially coaxially through a circular hole 30 formed in the base 16 and projects to the outside of the frame 12. A ratchet wheel 64, described below, is fixed to the support shaft section 29 at a projecting base end face of the support shaft section 29. The ratchet wheel 64 is thus able to rotate together with the coil 20.

[0019] Furthermore, a motor 38 is fixed to a gearbox housing 52, which serves as a housing and is described below. The motor 38 is arranged below the coil 20 between the pair of feet 16, 18 of the frame 12. It should be noted that a motor housing 240 (see below) Fig. 8) of the motor 38 is covered by a motor cover 34, and the motor cover 34 is fixed to the gearbox housing 52 using a screw 36.

[0020] Furthermore, an A-gear 40, which serves as a first gear, which is formed with a plurality of external teeth 41 on an outer circumferential section of the A-gear 40, is fixed to a rotating shaft 242 of the motor 38.

[0021] A support shaft section, not shown in the drawings, projects from an end section on the side of the base 18 of the coil 20. This support shaft section emerges substantially coaxially through a ratchet wheel hole (not shown in the drawings) formed in the base 18 and projecting to the outside of the frame 12. A locking base, against which a locking plate forming part of a locking mechanism is supported, is fixed to the support shaft section. In a vehicle emergency (for example, during sudden deceleration of the vehicle), the locking plate projects from the locking base and engages with the inner circumferential section of the ratchet wheel hole formed in the base 18, thereby preventing rotation of the coil 20 in the withdrawal direction. A cover 42, which covers the locking mechanism and the like, is fixed to the base 18.

[0022] The gearbox housing 52, in which a first clutch 44, a B-gear 46, an OL-gear 48 and a C-gear 50 are housed, is fixed to the base 16 by a screw 54.

[0023] As this is in Fig. As shown in Figure 2, the first clutch 44 is constructed in such a way that it has a clutch gear 56 formed in a ring shape, a locking rod 58 and a return spring 60 which are attached to the clutch gear 56, a friction spring 62 and the ratchet wheel 64 which is fixed to the coil 20.

[0024] More precisely, a multitude of external teeth 57 are formed on an outer circumferential section of the clutch gear 56, and, as shown in Fig. As shown in Figure 1, a circular insertion hole 56A, through which the support shaft section 29 of the coil 20 is inserted, is formed on an inner circumferential section of the clutch gear 56. Furthermore, a locking rod support shaft 56B and a return spring support shaft 56C, which project outwards towards the side of the foot piece 16 and are arranged separately from each other in the circumferential direction of the clutch gear 56, project outwards from a radially central section of the clutch gear 56. A friction spring insertion hole 56D, through which the friction spring 62 is inserted, is formed on a circumferentially central section of the clutch gear 56. As shown in Figure 1, the clutch gear 56 is formed on a circumferentially central section of the clutch gear 56. Fig. As shown in Figure 1, the clutch gear 56 described above is housed inside a recess formed on the side of the base 16 of the gearbox housing 52. A first seat 66 is attached to the gearbox housing 52, thereby limiting movement of the clutch gear 56 towards the side of the base 16.

[0025] As this is in Fig. As shown in Figure 2, a locking rod 58 is formed in a substantially crescent-shaped form when viewed along the axial direction of the clutch gear 56, and the locking rod 58 is able to be inclined (tilted) because it is supported by the locking rod support shaft 56B, which is provided on the clutch gear 56. One end section of the locking rod 58 forms a section 58A that engages with the ratchet wheel 64, and another end section of the locking rod 58 forms a return spring contact section 58B that is in contact with (behind) the return spring 60.

[0026] The return spring 60 has a coil section (winding section) 60A, which is wound in a ring shape and supported by the return spring support shaft 56C, which is provided on the clutch gear 56. One end section of the return spring 60 forms a captive section 60B, which extends outwards from the winding section (spiral section) 60A and is engaged by a portion of the clutch gear 56. Another end section of the return spring 60 forms a contact section 60C, which extends outwards from the winding section (spiral section) 60A and is in contact with the return spring contact section 58B of the locking bar 58. A thrust force of the return spring 60 is applied to the return spring assembly section 58B of the locking bar 58 such that the section 58A of the locking bar 58, which engages with the ratchet wheel, is held separately by the ratchet wheel 64.

[0027] As this is in Fig. As shown in Figure 1, the friction spring 62 is provided between the clutch gear 56 and the gearbox housing 52. The friction spring 62 has a sliding contact section 62A, which is in sliding contact with the gearbox housing 52 when the clutch gear 56 is rotated, and a pressure section 62B, which extends outwards from the sliding contact section 62A to the side of the clutch gear 56 and through the friction spring insertion hole 56D (see Figure 1). Fig. 2) is introduced, which is formed in the clutch gear 56. As this is shown in Fig. As shown in Figure 2, when the clutch gear 56 is rotated towards an axial direction (the side corresponding to the direction of arrow E1), the pressing section 62B of the friction spring 62 presses the section 58A of the locking bar 58 that engages with the ratchet wheel. Furthermore, if a force applied to the section 58A of the locking bar 58 that engages with the ratchet wheel by the pressing section 62B of the friction spring 62 exceeds the pushing force of the return spring 60, the locking bar 58 is inclined, and the section 58A of the locking bar 58 that engages with the ratchet wheel engages with the ratchet 64. A rotational force applied to the clutch gear 56 is thereby applied to the ratchet wheel 64 via the locking bar 58, and the spool 20 is rotated in the winding direction together with the ratchet wheel 64. In contrast, as this is shown in Fig. As shown in Figure 3, when the clutch gear 56 is rotated to the other axial direction side (the side in the direction of arrow E2), a force is applied to the section 58A of the locking bar 58 that engages with the ratchet wheel by the pressure section 62B of the friction spring 62, not the pushing force of the return spring 60. Thus, the section 58A of the locking bar 58 that engages with the ratchet wheel does not engage with the ratchet wheel 64. Accordingly, the rotational force applied to the clutch gear 56 is not applied to the ratchet wheel 64 by the locking bar 58.

[0028] The ratchet wheel 64 is designed in a circular disc shape. A plurality of external engagement teeth 64A, which engage with the section 58A of the locking bar 58 that engages with the ratchet wheel, are formed on an outer circumferential section of the ratchet wheel 64. As shown in Fig. As shown in Figure 1, the ratchet wheel 64 is fixed to the support shaft section 29 of the coil 20 by press fitting or the like.

[0029] The B-gear 46, which serves as a second gear, has a large-diameter section 46T formed on an outer circumferential section with a plurality of external teeth 47 that mesh with the external teeth 41 of the A-gear 40, and a small-diameter section 46S that is arranged coaxially with the large-diameter section 46T and is formed integrally with the large-diameter section 46T. An outer diameter of the small-diameter section 46S is defined as smaller than an outer diameter of the large-diameter section 46T, and an outer circumferential section of the small-diameter section 46S is formed with a plurality of external teeth 47S that mesh with the OL-gear 48, which is described below.

[0030] The OL gear 48 is designed such that it has an input gear which meshes with the B gear 46, and an output gear which is rotated by a torque transmitted through the input gear and meshes with the C gear 50. It should be noted that a limiting mechanism, not shown in the drawings, is provided between the input gear and the output gear to prevent the tension in the belt from reaching a predetermined value or exceeding it during pretensioning, as described below.

[0031] As this is in Fig. As shown in Figure 1, the C-gear 50 is designed in a circular disc shape with a plurality of external teeth 51. These teeth mesh with the external teeth of the output gear forming part of the OL gear 48 and with the external teeth 57 of the clutch gear 56 forming part of the first clutch 44. The C-gear 50 rotates the clutch gear 56 because the C-gear 50 is rotated by the output gear of the OL gear 48.

[0032] The B-gear 46, the OL-gear 48 and the C-gear 50 described above are rotatably supported on respective shaft sections provided inside a housing recess 52A in a state in which they are located inside the housing recess 52A formed in the gear housing 52.

[0033] A spring holder 84, on which an idle gear 78, a coil gear 80, a retraction spring 82 and a second clutch 116 are supported, is fixed to the gearbox housing 52.

[0034] The idle gear 78 is formed in a circular disc shape. A plurality of external teeth 79, which mesh with the coil gear 80 and the second clutch 116 as described below, are formed on an outer circumferential section of the idle gear 78. In a state where it is housed inside a recess formed at a location on the side of the gear housing 52 of the spring retainer 84, the idle gear 78 is rotatably supported on a shaft section that projects outwards inside the recess. A second seat 86 is provided on the spring retainer 84, thereby limiting movement of the idle gear 78 towards the side of the gear housing 52.

[0035] The coil gear 80 is designed in a circular disc shape with a larger diameter than the idle gear 78. A plurality of external teeth 81, which mesh with the external teeth 79 of the idle gear 78, are formed on an outer circumferential section of the coil gear 80. An adapter fixing section 80A is designed such that it projects outwards towards the side of the retraction spring 82 on an axially central section of the coil gear 80. A engagement hole, not shown in the drawings, with which the support shaft section 29 of the coil 20 engages, is formed at a location on the side of the coil 20 of the axially central section of the coil gear 80. The engagement hole of the coil gear 80 engages with the support shaft section 29 of the coil 20, whereby the coil gear 80 and the coil 20 are coupled in such a way that they are able to rotate together as one unit.The coil gear 80 is housed inside a housing recess formed at a location on the side of the gear housing 52 of the spring holder 84. When the coil gear 80 is housed inside the housing recess, the adapter fixing section 80A of the coil gear 80 projects outwards towards the side of the retraction spring 82 through an insertion hole 84A formed in a bottom wall of the housing recess.

[0036] The retraction spring 82 is formed in a spiral shape and is housed inside a spring housing section 84B, which is formed on the spring holder 84 on the side opposite the side on which the coil gear 80 is housed. An inner end section of the retraction spring 82 is engaged by an adapter 88, which is fixed to the adapter fixing section 80A of the coil gear 80. An outer end section of the retraction spring 82 is anchored to an anchoring section (not shown in the drawings) formed inside the spring housing section 84B. A pushing force from the retraction spring 82 is transmitted to the coil 20 through the adapter 88 and the coil gear 80, such that the coil 20 is forced to rotate in the winding direction.It should be noted that the retraction force of the retraction spring 82 (a winding force in the belt resulting from the retraction force) is set at a comparatively weak level, eliminating belt sag when the belt is fastened by an occupant. In other words, the retraction force of the retraction spring 82 is set at a strength that does not restrict the occupant when wearing (fastening) the belt and does not require sufficient force to fully wind the belt, which is pulled from the spool 20, against the frictional forces and the like acting on the belt.

[0037] A spring cover 90 is attached to the spring holder 84. The retraction spring 82, which is housed inside the spring housing section 84B, is thereby covered by the spring cover 90.

[0038] The Fig. 4 and Fig. Figure 5 shows perspective exploded views of the assembly of the second coupling 116. Fig. Figure 6 shows a cross-sectional view of the second coupling 116. How this is in the Fig. 4, Fig. 5 to Fig. As shown in Figure 6, the second clutch 116 has a base 118 and a rotor plate 128, which is attached to the base 118 so that it rotates as a unit together with the base 118. The second clutch 116 also has a clutch gear 136, a clutch spring 140 located between the base 118 and the clutch gear 136, and a lever 148 rotatably supported by the base 118. The second clutch 116 also has a pair of clutch weights 170, 172 supported by the base 118, and a spacer 184 attached to the base 118.

[0039] The base 118 has a circular section 120, which is formed in a circular disc shape, a circular column-shaped support shaft section 122, which projects towards an axial direction side of the circular disc section 20 at an axially central section of the circular disc section 120, and a side wall section 124 with a substantially C-shaped cross-section, which is formed coaxially around the support shaft section 122. The base 118 also has a block-shaped first spring-capture section 125, which is formed with a first spring-capture groove 125A in which an end section of one side of the clutch spring 140 is captured, and which projects outwards in the same direction as the projection direction of the support shaft section 122.An outer surface of the first spring-capture section 125, viewed in a radial direction, is formed with a circular cylindrical surface shape with the same radius of curvature as an outer circumferential surface of the side wall section 124.

[0040] As this is in Fig. As shown in Figure 7A, a first spring-capture groove 125A is formed in the first spring-capture section 125 in a groove shape that is open on the radially viewed outer side and on an axially directed side (the side of the rotor plate 128) of the base 118. The first spring-capture groove 125A is constructed such that it has side wall sections K1, K2, which are arranged parallel to each other with a separation space (intermediate space) between them, and a bottom wall section K3, which forms an end face in a depth direction of the first spring-capture groove 125A. Viewed along the axial direction of the base 118, the side wall sections K1, K2 are inclined around the axis of the base 118, progressively towards the radially viewed inner side of the base 118 and towards another side (the side in the direction of arrow F1).A groove width W1 of the first spring-capture groove 125A, namely a space between the side wall section K1 and the side wall section K2, is set to a width that is slightly larger than the wire diameter of the first capture section 142 of the clutch spring 140, which is described below. It should be noted that an open end of the first spring-capture groove 125A on one axial direction side of the base 118 is closed by the rotor plate 128, as described below.

[0041] As this is shown in the Fig. 4 and Fig. As shown in Figure 5, the base 118 has a circular cylindrical support shaft section 123 projecting from the side of the circular disc section 120 opposite the side provided with the support shaft section 122. On the radially outer side of the support shaft section 123, the circular disc section 120 of the base 118 also has support shafts 176, 178 projecting outwards towards the side of the coupling weights 170, 172. The support shafts 176, 178 are arranged at uniform intervals around the circumference of the base 118. A pair of elongated holes 160, 162 are formed around the circumference of the base 118 at locations on the radially outer side of the support shaft sections 122, 123 on the circular disc section 120 of the base 118.The coupling projections 156, 158 of the lever 148, described below, engage with the elongated holes 160, 162, and the coupling projections 156, 158 are able to move about the circumferential direction of the circular disc section 120 within the respective elongated holes 160, 162. A retaining wall 127, which abuts an end section of a return spring 164 described below, projects outwards from the circular disc section 120.

[0042] As this is in Fig. As shown in Figure 6, the base 118 described above is arranged inside a housing recess (mounting recess) 84C, which is formed in the spring holder 84 and is rotatably supported by a shaft section 84D that projects outwards in the housing recess 84C.

[0043] As this is shown in the Fig. 4 and Fig. As shown in section 5, the rotor plate 128, which is formed in a circular disk shape, is located at an axial direction end face (the right side in the Fig. 4 and Fig. 5) of the support shaft section 122 of the base 118. The rotor plate 128 engages with a claw provided on the side wall section 124 of the base 118 in such a way that the rotor plate 128 is fixed so that it is able to rotate as a unit together with the base 118. A circular shaft support hole 129 is formed on an axial center section of the rotor plate 128, and an input gear 200, described below, is rotatably supported by the shaft support hole 129. The rotor plate 128 is rotated, i.e., the second clutch 116 is rotated, by applying a rotational force from the input gear 200, described below, to the rotor plate 128 via a secondary clutch spring 202.

[0044] At the base 118, the coupling gear 136 is provided coaxially to the base 118 on the radially viewed outer side of the side wall section 124 and is able to rotate relative to the base 118. Multiple external teeth 138 are formed on an outer circumferential section of the coupling gear 136. The external teeth 138 are in conjunction with the external teeth 79 (see figure). Fig. 1) of the above-described idle gear 78 in tooth mesh. An inner diameter dimension of the clutch gear 136 is sufficiently larger than an outer diameter dimension of the side wall section 124 of the base 118, and an annular space is formed between an inner circumferential surface of the clutch gear 136 and the outer circumferential surface of the side wall section 124. The clutch spring 140, which consists of a torsion helical spring (torsion spiral spring), is arranged coaxially in the annular space.

[0045] The clutch spring 140 has a winding section (spiral section) 141, which is wound into a ring shape, between the outer circumferential surface of the side wall section 124 of the base 118 and the inner circumferential surface of the clutch gear 136. An end section on one side of the clutch spring 140 is bent towards the radially viewed inner side of the winding section 141 such that it forms the first captive section 142. As this is shown in Fig. As shown in Figure 7A, the first capturing section 142 has an inclination with respect to the radial direction of the winding section 141 that corresponds to that of the first spring capturing groove 125A described above. An end section on the other side of the coupling spring 140 is bent towards the radially oriented inner side of the winding section 141 such that it forms a second capturing section 146. The second capturing section 146 extends along the radial direction of the winding section 141 corresponding to a second spring capturing groove 153A formed in the lever 148 and described below. The first capturing section 142 and the second capturing section 146 are arranged at a predetermined distance from each other around the circumferential direction of the winding section 141.The inner diameter of the winding section 141, when in its natural state, is smaller than the outer diameter of the side wall section 124 of the base 118. Accordingly, when the winding section 141 is installed on the side wall section 124 of the base 118, its diameter decreases due to its own elastic force. The winding section 141 thus comes into close contact with the outer circumferential surface of the side wall section 124 of the base 118 when installed. A gap is provided between the winding section 141 and the inner circumferential surface of the coupling gear 136 when the winding section 141 is installed on the side wall section 124 of the base 118.

[0046] The first retaining section 142 of the clutch spring 140 sits in and is retained in the first spring retaining groove 125A, which is formed in the first spring retaining section 125 of the base 118. Furthermore, the second retaining section 146 of the clutch spring 140 sits in and is retained in the second spring retaining groove 153A, which is formed in a second spring retaining section 153 of the lever 148, as described below.

[0047] The lever 148 has a circular cylindrical shaft bearing section 150. The support shaft section 122 of the base 118 passes through the interior of the cylinder of the shaft bearing section 150, thus supporting the lever 148 so that it can rotate relative to and about the axis of the support shaft section 122 (base 118). An outer circumferential section of the shaft bearing section 150 is provided with a coupling section 152 and a coupling section 154, which form a pair and project outwards along the radial direction on opposite sides to each other around the circumferential direction (opposite sides at 180° to each other).

[0048] As this is in Fig. As shown in Figure 5, the circular-column coupling projection 156 and the circular-column coupling projection 158 are designed to project outwards from the pair of respective coupling sections 152, 154 towards the side of the circular disc section 120 of the base 118. The respective coupling projections 156, 158 engage with the engagement claws 180, 182 provided on the pair of coupling weights 170 and 172, as described below.

[0049] As this is shown in the Fig. 7A and Fig. As shown in Figure 7B, one coupling section 152 of the lever 148 is in contact with an end section of the return spring 164, which is a torsion coil spring. Another end section of the return spring 164 rests against the captive wall 127, which projects outwards from the circular disc section 120 of the base 118. The return spring 164 constantly pushes the lever 148 in a direction around the axis of the base 118 (in the direction of arrow F1). The coupling projections 156, 158 of the lever 148, which are arranged as a pair, are normally held in a position where they are against an end section viewed longitudinally (end sections on the side in the direction of arrow F1 in the Fig. 4 and Fig. 5) each of the pair rests on elongated holes 160, 162 of the circular disk section 120.

[0050] As this is in Fig. As shown in Figure 7A, the other clutch section 154 of the lever 148 is configured as the second spring retaining section 153, in which the second retaining section 146 of the clutch spring 140 is engaged (grasped). The second spring retaining section 153 is formed with the second spring retaining groove 153A, in which the second retaining section 146 of the clutch spring 140 sits. Accordingly, as shown in the Fig. 7A and Fig. As shown in Figure 7B, when the lever 148 rotates in the opposite direction (the direction of arrow F2) about the axis with respect to the base 118 against the elastic force of the return spring 164, the second captive section 146 of the clutch spring 140 moves in one winding direction of the clutch spring 140 (the direction of arrow F2), thereby increasing the outer diameter dimension of the winding section 141 of the clutch spring 140. The second spring captive groove 153A is constructed such that it has side wall sections K4, K5 and a bottom wall section K6 in a similar manner to the first spring captive groove 125A described above. In the present embodiment, in a state where the lever 148 is supported by the base 118, the side wall sections K4, K5 are substantially parallel to the radial direction of the base 118.A groove width W2 of the second spring retaining groove 153A, namely a distance between the side wall section K4 and the side wall section K5, is defined as a width sufficiently wider than the wire diameter of the second retaining section 146 of the clutch spring 140. The clutch spring 140 can therefore be installed with favorable ease on the base 118 and the lever 148.

[0051] Furthermore, when the outer diameter of the winding section 141 of the clutch spring 140 is increased in this way, the winding section 141 of the clutch spring 140 presses against the inner circumferential surface of the clutch gear 136. In this state, a predetermined frictional force arises between an outer circumferential section of the clutch spring 140 and the inner circumferential surface of the clutch gear 136 in such a way that the frictional force couples the clutch spring 140 and the clutch gear 136 integrally.

[0052] As this is shown in the Fig. 4, Fig. 5 to Fig. As shown in Figure 6, the coupling weights 170 and 172, designed as a pair and each formed in essentially semicircular plate shapes, are arranged on a different axial direction side of the base 118 (the side opposite the rotor plate 128). The coupling weights 170 and 172 are fixed with the same weight and are positioned on opposite sides of each other around the circumferential direction of the circular disk section 120 (at sides 180° opposite each other). Circular shaft bearing holes 174 and 175 are formed on each of the circumferential sides of the pair of coupling weights 170 and 172. The circular column-shaped support shaft 176 and the support shaft 178, which projects outwards from the circular disk section 120 of the base 118, are rotatably mounted in the respective shaft bearing holes 174 and 175.The respective coupling weights 170, 172 are supported by the base 118 in such a way that they are rotatable about the respective support shafts 176, 178 (shaft bearing holes 174, 175) in the radial direction of the base 118 (are able to tilt).

[0053] One clutch weight 170 has the substantially U-shaped engagement claw 180, which engages with the clutch projection 158 of the lever 148 described above. Similarly, the other clutch weight 172 has the substantially U-shaped engagement claw 182, which engages with the clutch projection 156 of the lever 148. The clutch weights 170 and 172, provided as a pair, are thereby synchronized (mutually locked) by the lever 148 and are normally held on the radially inner side of the base 118 by the compressive force of the return spring 164 acting on the lever 148.

[0054] As this is shown in the Fig. 4, Fig. 5 to Fig. As shown in Figure 6, the circular, disc-shaped spacer 184 is arranged on the side of the pair of coupling weights 170, 172 opposite the base 118. A tubular hub section 184A, which sits together with an outer circumferential section of the support shaft section 123 of the base 118, projects outwards from a central section of the spacer 184. The spacer 184 prevents the coupling weights 170, 172, which are arranged as a pair, from falling out of the base 118 and also prevents the coupling weights 170 and 172, which are arranged as a pair, from coming into contact with a bottom wall of the housing recess 84C of the spring holder 84.

[0055] It should be noted that in the second coupling 116 of the present embodiment, when the rotor plate 128 moves in one direction (the direction of arrow F1 in the Fig. 4 and Fig. 5) As the base 118, which is integrally coupled to the rotor plate 128, rotates about its axis in one direction together with the rotor plate 128, the coupling weights 170 and 172, provided as a pair, rotate about the axis of the base 118, supported by the base 118, by following the base 118. When this occurs, a centrifugal force acts on the pair of coupling weights 170 and 172 such that a torque acts on coupling weight 170 about the support shaft 176 and a torque acts on coupling weight 172 about the support shaft 178.

[0056] Accordingly, when the magnitudes of the torques are at a predetermined value or greater, namely when the rotational speeds of the pair consisting of the clutch weight 170 and the clutch weight 172 are at a predetermined value or greater, the clutch weights 170 and 172, provided as a pair, each rotate about the support shaft 176 or support shaft 178 towards the radially viewed outer side of the base 118 against the thrust force of the return spring 164 acting on the lever 148. Accordingly, an assembly is designed such that the lever 148, in which the clutch projection 158 engages with the engagement claw 180 of the clutch weight 170 and in which the clutch projection 156 engages with the engagement claw 182 of the clutch weight 172, rotates in the other direction (the direction of arrow F1 in the Fig. 7A and Fig. 7B) rotates around the axis with respect to the base 118.

[0057] In the present embodiment, the structure is designed such that a rotational force of the rotating shaft 142 of the motor 38 is transmitted to the rotor plate 128 through the A-gear 40, the B-gear 46, the OL-gear 48, the input gear 200 and the auxiliary clutch spring 202, which serves as a clutch and a clutch spring.

[0058] As this is in Fig. As shown in Figure 6, the input gear 200 is constructed such that it has a shaft section 208, which is rotatably supported by the shaft support hole 129 of the rotor plate 128, and a gear section 211, which is integrally formed on the shaft section 208. The shaft section 208 is formed in a substantially circular cylindrical shape, and an end section of the shaft section 208 on the side facing the rotor plate 128 engages with the shaft support hole 129 of the rotor plate 128. Furthermore, the auxiliary clutch spring 202 engages with an outer circumferential surface of a section of the shaft section 208 on the side opposite the rotor plate 128. The auxiliary clutch spring 202, described below, is press-fitted to the shaft section 208 such that the input gear 200 and the auxiliary clutch spring 202 rotate together as a single unit.Furthermore, the gear section 211 is provided at an end section on one side of the shaft section 208, and external teeth 212 of a spur gear (spur gear) are formed on an outer circumferential section of the gear section 211. The external teeth 212 mesh with the external teeth of the input gear, which forms part of the OL gear 48, as described above.

[0059] As this is in Fig. As shown in Figure 4, the auxiliary clutch spring 202 is provided between the input gear 202 and the rotor plate 128. The auxiliary clutch spring 202 is designed, for example, such that a wire-shaped element is bent. The auxiliary clutch spring 202 has a winding section 216 that is wound in a ring shape around the outer circumferential surface of the shaft section 208 of the input gear 200. In addition, an end section of the auxiliary clutch spring 202 is formed on the side of the rotor plate 128 with a capping section 218 that is bent towards the radially viewed outer side of the winding section 216. The winding section 216 is formed by winding the wire-shaped element in a spiral shape around its axis (in the direction of arrow F1) on the side opposite the direction of the capture section 218, when viewed from the opposite side.Furthermore, the inner diameter of the winding section 216, when in its natural state, is specified as smaller than—or the same as—the outer diameter of the shaft section 208. Accordingly, the winding section 216 is designed to bear against the outer circumferential surface of the shaft section 208 when the auxiliary clutch spring 202 is in an assembled state on the shaft section 208.

[0060] An inner circumferential edge section of the support shaft hole 129 of the rotor plate 128 is formed with a capture groove 218B, on which the capture section 218 of the auxiliary clutch spring 202 is captured.

[0061] Furthermore, when the input gear 200 is rotated about its axis to one side (direction of arrow F1), the outer diameter of the winding section 216 attempts to contract as a result of the frictional force between the shaft section 208 of the input gear 200 and the winding section 216 of the auxiliary clutch spring 202. Consequently, the winding section 216 comes into close contact with the shaft section 208, and the input gear 200 is rotated about its axis to the other side (direction of arrow F1) along with the auxiliary clutch spring 202. As a result, a rotational force from the input gear 200 to one side (direction of arrow F1) is transmitted to the rotor plate 128 via the auxiliary clutch spring 202, and the second clutch 116 is rotated about its axis to one side (direction of arrow F1).

[0062] Furthermore, when the input gear 200 is rotated about its axis in the other direction (direction of arrow F2), the outer diameter of the winding section 216 tends to increase as a result of the frictional force between the shaft section 208 of the input gear 200 and the winding section 216 of the auxiliary clutch spring 202. The shaft section 208 therefore rotates freely relative to the winding section 216. As a result, the transmission of the rotational force of the input gear 200 about its axis to the rotor plate 128 in the other direction (direction of arrow F2) is blocked, and the second clutch 116 is not rotated about its axis in the other direction (direction of arrow F2).

[0063] The detailed construction of the motor 38 and the gearbox housing 52, which are relevant sections of the present embodiment, is explained below.

[0064] As this is in Fig. As shown in Figure 8, the motor 38 of the present embodiment is a DC motor. The motor 38 has a rotor 244 and a stator 246. The rotor 244 is constructed such that it has the rotating shaft 242, a rotor core 248 fixed to the rotating shaft 242, a conductive coil (not shown in the drawings) wound around the rotor core 248, and a commutator (not shown in the drawings) fixed to the rotating shaft 242 to switch the current flow to the coil wound around the rotor core 248. The stator 246 is constructed such that it connects the motor housing 240 at an axially central section, where the rotor 244 is arranged such that most of the rotor 244 is covered, and has magnets 250 fixed to an inner circumferential surface of the motor housing 240.The motor housing 240 has a tubular section 252, which is formed in a tube shape and to whose inner circumferential surface the magnets 250 are fixed, and a first side wall section 254 and a second side wall section 256, each designed to close one end section and another end section of the tubular section 252. A first hub section 258, which serves as an engagement section within which a shaft bearing is arranged that supports a portion of the rotating shaft 242, is designed to project from an axially central section of the first end section 254. A second hub section 260, within which a shaft bearing is arranged that supports another portion of the rotating shaft 242, is designed to project outwards from an axially central section of the second side wall section 256.Furthermore, the respective outer circumferential surfaces 258A and 260A of the first hub section 258 and the second hub section 260 are constructed with circular cylindrical surface profiles, which are arranged coaxially to the rotating shaft 242.

[0065] As this is in Fig. As shown in Figure 9, a B-gear support section 264, which serves as a support section for a second gear to which a shaft section 262 is fixed and which rotatably supports the B-gear, is provided inside the housing recess (concave section) 52A of the gearbox housing 52. Furthermore, a motor fixing section 266, to which the motor 38 (see Figure 9) is attached, is provided. Fig. 1 and Fig. 8) is fixed at a location adjacent to (next to) the B-gear support section 264 within the housing recess 52A of the gearbox housing 52. An engagement hole 270, which serves as an engagement section and is provided with four projections 268 on an inner circumferential section, is formed in the motor fixing section 266. It should be noted that the projection height of the projections 268 in Fig. 9 is exaggerated.

[0066] The profile of an inner circumferential surface 270A of a location of the engagement hole 270, wherein the projections 268 are not formed at this location, is formed as a circular cylindrical surface profile with an inner diameter D1 which is larger than the outer diameter of the outer circumferential surface 258A of the first hub section 258 (see figure). Fig. 8) of the motor housing 240. Furthermore, the four projections 268 are arranged at equal intervals around the circumferential direction of the inner circumferential surface 270A at the location of the engagement hole 270, with the projections 268 not being formed at this location. In addition, an imaginary circle 272 passing through projection-direction guide ends of the projections 268 has an inner diameter D2 that is defined as smaller than the outer diameter of the outer circumferential surface 258A of the first hub section 258 (see figure). Fig. 8) of the motor housing 240. Two fixing screw insertion holes 274, into which fixing screws not shown in the drawings are inserted, are formed around the vicinity (surroundings) of the engagement hole 270 of the motor fixing section 266.

[0067] Furthermore, as is stated in the Fig. 8 and Fig. As shown in Figure 9, when the first hub section 258 of the motor housing 240 is inserted into the engagement hole 270 formed in the motor fixing section 266, the four projections 268 between the outer circumferential surface 258A of the first hub section 258 and the inner circumferential surface 270A of the location of the engagement hole 270 are deformed, with the projections 268 not being formed at this location. The first hub section 258 thus engages with the engagement hole 270 in such a way that a fastening tolerance (in other words, an interference fit or a clamping fit) exists between them.

[0068] For example, the fastening tolerance corresponds to a measure of a difference between a radius of the imaginary circle 272 passing through the projection directional guide ends of the four projections 268 before deformation (half the inner diameter D2) and a radius of the outer circumferential surface 258A of the first hub section 258 (half the outer diameter of the outer circumferential surface 258A), in other words, it corresponds to the deformed amount of the projection 268 in a case where only the projections 268 are deformed.

[0069] Furthermore, the fixing screws not shown in the drawings, which are inserted into the two fixing screw insertion holes 274 formed in the motor fixing section 266 around the area of ​​the engagement hole 270, are in fixing screw insertion holes 276 (see. Fig. 1) screwed, which are formed in the first side wall section 254 of the motor housing 240, whereby the motor 38 is fixed to the motor fixing section 266 of the gearbox housing 52. Operation and advantageous effects of the present embodiment

[0070] The operation and advantageous effects of the present embodiment are explained below.

[0071] As this is in Fig. As shown in Figure 1, in the belt winding device 10, which is constructed as described above, in a housed state of the belt which is wound in a layered form on the spool 20, when the belt is pulled while pulling on a tongue plate not shown in the drawings, the belt is pulled out while the spool 20 is rotated in the pulling direction against the pushing force of the retraction spring 82, which pushes the spool 20 towards the winding direction.

[0072] In a state where the belt is extended, the belt is placed over the body of an occupant by coupling the belt around the front part of the body of the seated occupant, inserting the tongue plate into the belt buckle device, and holding the tongue plate in the belt buckle device.

[0073] When the insertion of the tongue plate into the belt buckle device is detected by a switch or the like (not shown in the drawings), a motor control device (not shown in the drawings) rotates the rotating shaft 242 of the motor 38 in a forward direction. The rotation of the rotating shaft 242 of the motor 38 is transmitted to the coil via a first transmission route, which is located in Fig. Figure 10 shows this. More precisely, the rotating shaft 242 of the motor 38 rotates the A-gear 40 in the direction of arrow A1. When the A-gear 40 is rotated in the direction of arrow A1, the B-gear 46 is rotated in the direction of arrow B1 by the A-gear 40, and the OL-gear 48 is rotated in the direction of arrow C1 by the B-gear 46. Furthermore, the C-gear 50 is then rotated in the direction of arrow D1 by the OL-gear 48, and the clutch gear 56 of the first clutch 44 is rotated in the direction of arrow E1 by the C-gear 50. It should be noted that when the clutch gear 56 is rotated in the direction of arrow E1, the locking bar 58 engages with the ratchet wheel 64. As a result, the rotation of the coupling gear 56 is transmitted to the ratchet wheel 64, and the coil 20 rotates in the winding direction together with the ratchet wheel 64.The belt is thereby wound onto the spool 20, eliminating any sag in the belt fastened by the occupant (this is referred to below as "fitting support"). Then, in a state where the rotating shaft 242 of the motor 38 has stopped rotating, the belt holds the occupant with a relatively weak force as a result of the retraction force of the retraction spring 82.

[0074] In a moving vehicle, if a detection device (not shown in the drawings) detects, for example, a sudden deceleration of the vehicle, the motor control device (not shown in the drawings) rotates the motor shaft 242 in the forward direction. When this occurs, the torque on the motor shaft 242 is set higher than the torque during the aforementioned fitting support. The forward rotation of the motor shaft 242 is transmitted to the coil 20 by the Fig. 10 first transmission route shown, such that the belt is wound onto the spool 20, thereby removing any sagging of the belt fitted by the occupant (this is referred to as "pretensioning").

[0075] On the other hand, if the vehicle occupant stops and releases the tongue plate from the seatbelt buckle, the spool 20 rotates in the winding direction under the pulling force of the retraction spring 82. However, since the pulling force of the retraction spring 82 is set to be comparatively weak, the spool 20 rotates in the winding direction with a comparatively weak rotational force, which corresponds to the pulling force of the retraction spring 82.

[0076] At this point, the motor control device (not shown in the drawings) rotates the rotating shaft 242 of the motor 38 in the reverse direction. The rotation of the rotating shaft 242 of the motor 38 is transmitted to the coil 20 via a second transmission path, which is located in Fig. Figure 11 shows that the reduction ratio (sampling ratio) of the second transmission route is set higher than the reduction ratio (sampling ratio) of the first transmission route described above.

[0077] When the rotating shaft 242 of motor 38 is rotated in the reverse direction, the rotating shaft 242 of motor 38 rotates the A-gear 40 in the direction of arrow A2. When the A-gear 40 is rotated in the direction of arrow A2, the B-gear 46 is rotated in the direction of arrow B2 by the A-gear 40, and the OL-gear 48 is rotated in the direction of arrow C2 by the B-gear 46. Then the input gear 200 is rotated in the direction of arrow F1 by the OL-gear 48. When this happens, as shown in the Fig. 4, Fig. 5 to Fig. As shown in Figure 6, the rotational force of the input gear 200 is transmitted to the rotor plate 128 of the second clutch 116 by the auxiliary clutch spring 202, and the rotor plate 128 is rotated in the direction of arrow F1 together with the base 118.

[0078] The rotation of the base 118 is transmitted to the clutch weight 170 via the support shaft 176 and the shaft bearing hole 174, and to the clutch weight 172 via the support shaft 178 and the shaft bearing hole 175, causing the clutch weight 170 and the clutch weight 172 to rotate about the axis of the base 118. Consequently, a centrifugal force acts on the clutch weight 170 and the clutch weight 172. As a result, the clutch weight 170 and the clutch weight 172 rotate (tilt) towards the radially outer side of the base 118 about the support shafts 176 and 178, and against the thrust force of the return spring 164 acting on the lever 148.

[0079] Accordingly, lever 148 rotates in the opposite direction around the axis (the direction of arrow F2 in the Fig. 7A and Fig. 7B) with respect to the base 118, wherein the coupling projection 158 engages with the engagement claw 180 of the coupling weight 170 and the coupling projection 156 engages with the engagement claw 182 of the coupling weight 172.

[0080] When the lever 148 rotates about the axis in the opposite direction with respect to the base 118, the second captive section 146 of the clutch spring 140 becomes aligned with one winding direction of the clutch spring 140 (the direction of arrow F2 in the Fig. 7A and Fig. 7B) is moved by the lever 148. As a result, the outer diameter of the winding section 141 of the clutch spring 140 is increased, which brings the outer circumferential section of the winding section 141 of the clutch spring 140 into close contact with the inner circumferential surface of the clutch gear 136. Accordingly, the rotation of the clutch spring 140 is transmitted to the clutch gear 136, and the clutch gear 136 rotates in the direction of arrow F1. As this is shown in Fig. As shown in Figure 11, the outer teeth 138 of the clutch gear 136 mesh with the outer teeth 79 of the idle gear 78 in such a way that the idle gear 178 is rotated in the direction of arrow G1. The spool gear 80 is rotated in the direction of arrow H1 by the idle gear 78, which in turn rotates the spool 20 in the winding direction together with the spool gear 80. The rotation of the spool 20 results in insufficient force on the retraction spring 82 to wind and position the belt in a layered form on the spool 20 (this is known as "winding support").

[0081] Furthermore, in such cases, since the spool 20 is rotated at a lower speed than during the aforementioned fitting support, the belt can be securely wound and stored on the spool 20. Moreover, in the present embodiment, the belt can be easily pulled out of the spool 20 even when the aforementioned winding support is in place. This is because the spool 20 can be easily rotated in the pull-out direction against the torque of the winding support.

[0082] When the belt has been completely wound onto the spool 20, the power supply to the motor 38 is switched off by the motor control device, thereby stopping the rotation of the motor 38's rotating shaft 242. When the rotation of the motor 38 stops, the clutch weight 170 and the clutch weight 172 rotate towards the radially inward side of the base 118 due to the elastic force of the clutch spring 140 and the elastic force of the return spring 164 acting on the lever 148. The clutch spring 140 thus returns once again to its natural state, and the outer circumferential section of the winding section 141 separates from the inner circumferential surface of the clutch gear 136, immediately disengaging (releasing) the clutch between the clutch spring 140 and the clutch gear 136 as described above.The coupling of the spool 20 and the rotating shaft 242 of the motor 38 by the second coupling 116 is thereby lifted, which makes it possible for the belt wound on the spool 20 to be pulled out again.

[0083] It should be noted that the construction is designed in such a way that a rotation of the rotating shaft 242 of the motor 38 in the reverse direction during the winding support is not transmitted to the coil 20 through the first transmission route (via the A gear 40, the B gear 46, the OL gear 48, the C gear 50 and the first clutch 44).

[0084] As this is in Fig. As shown in Figure 11, during the fitting support and pre-tensioning phases, the forward rotation of the motor 38's drive shaft 242 is transmitted to the input gear 200 via gear A 40, gear B 46, and gear OL 48, and the input gear 200 is rotated in the direction of arrow F2. When this occurs, the input gear 200 rotates freely relative to the auxiliary clutch spring 202, preventing the torque of the input gear 200 from being transmitted to the rotor plate 128 via the auxiliary clutch spring 202. In this embodiment, the second clutch 116 is able to prevent rotation of the second clutch 116 in cases where there is no need to transmit the torque of the input gear 200 to the coil 20 via the idle gear 78 and the coil gear 80. In other words, non-essential actuation (rotation) of the clutch spring 116 can be avoided.

[0085] The operation and advantageous effects of the belt winding device 10 according to the present embodiment are explained below.

[0086] As this is shown in the Fig. 8 and Fig. As shown in Figure 9, in the present embodiment, the first hub section 258 of the motor housing 240 engages with the engagement hole 270, which is formed in the motor fixing section 266, such that the fastening tolerance exists between them. This enables a variation during the separation (disconnection) between the rotating shaft 242 of the motor 38 and the rotating shaft (shaft section 262) of the B-gear 46 to be suppressed. Accordingly, as shown in Figure 9, the following applies: Fig. As shown in Figure 11, the outer teeth 11 of gear A 40 and the outer teeth 47T of the large-diameter section 46T of gear B 46 mesh stably with each other, thereby reducing operating noise during rotation of the coil 20 under the driving force of the motor 38. Specifically, operating noise during winding support can be reduced.

[0087] Furthermore, in the present embodiment, the first hub section 258 of the motor housing 240 is inserted into the engagement hole 240, which is formed in the motor fixing section 266, such that the four projections 268 between the outer circumferential surface 258A of the first hub section 258 and the inner circumferential surface 270A of the engagement hole 270 are deformed at the location where the projections 268 are not formed. In this way, the provision of the deformable projections 268 in the present embodiment allows the first hub section 258 of the motor housing 240 to easily engage with the engagement hole 270 of the motor fixing section 266 in a state in which the fastening tolerance between them exists.

[0088] It should be noted that the present embodiment describes an example in which the first hub section 258 of the motor housing 240 engages with the engagement hole formed in the motor fixing section 266 such that the fastening tolerance between them exists as a result of the projections 268 being deformed between the outer circumferential surface 258A of the first hub section 258 and the inner circumferential surface 270A of the engagement hole 270 at the location where the projections 268 are not formed. However, the present embodiment is not limited to this.For example, the profile of the inner circumferential surface 270A of the engagement hole 270 formed in the motor fixing section 266 can have a profile corresponding to the profile of the outer circumferential surface 258A of the first hub section 258 of the motor housing 240, and the first hub section 258 of the motor housing 240 can be gently pressed and fitted into the engagement hole 270 in the motor fixing section 266 such that the first hub section 258 of the motor housing 240 engages with the engagement hole 270 of the motor fixing section 266 in a state where the fastening tolerance exists between them. Furthermore, as shown in... Fig. Figure 12 shows a flexible strip (or several flexible strips) 278, which can undergo bending deformation towards the outer side of the inner circumferential surface 270A of the engagement hole 270 as viewed in the radial direction, and which is present at an inner circumferential section of the engagement hole 270. In such a configuration, when the first hub section 258 of the motor housing 240 is inserted into the engagement hole 270 of the motor fixing section 266, the flexible strip 278 bends, and the flexible strip 278 is deformed between the outer circumferential surface 258A of the first hub section 258 and the inner circumferential surface 270A of the engagement hole 270. The first hub section 258 of the motor housing 240 thus engages with the engagement hole 270, which is formed in the motor fixing section 266, in such a way that a fastening tolerance exists between them.

[0089] Furthermore, the present embodiment describes an example in which a plurality of the projections 268 are arranged at uniform intervals around the circumferential direction of the inner circumferential surface 270A of the engagement hole 270 at a location where the projections 268 are not formed (i.e., the outer circumferential surface 258A of the first hub section 258 and only the deformed sections of the projections 268 abut each other; i.e., the section of the inner circumferential surface 270A of the engagement hole 270 at the location where the projections 268 are not formed and the outer circumferential surface 258A of the first hub section 258 do not abut each other). However, the present embodiment is not limited to this. For example, as shown in the Fig. 13 and Fig. As shown in Figure 14, the multitude of projections 268 are arranged in a compressed (concentrated) arrangement around a part of the inner circumferential surface 270A of the engagement hole 270.

[0090] As this is in Fig. As shown in Figure 13, a plurality (three) of the projections 268 are arranged crowded together on a part of the inner circumferential surface 270A of the engagement hole 270, wherein a part on the side of the engagement hole 270, which is on one side of an axial center 280 of the shaft section 262, is on a section which is divided by a line L, wherein the line L passes through the axial center 280 of the shaft section 262 (see Figure 13). Fig. 9), which supports the B-gear 246, passes through a center point 282 of an inner circumferential surface 270A at a location of the engagement hole 270 where the projections 268 are not formed. Furthermore, it shows Fig. 14 a plurality (three) of projections 268 arranged crowded together on a portion of the inner circumferential surface 270A of the engagement hole 270, one portion being on the side opposite the engagement hole 270 to the side of the axial center 280 of the shaft section 262 on a section intersected by line L. The Fig. 13 and Fig. The 14 assembly options shown allow the first hub section 258 of the motor housing 240, which is inserted into the engagement hole 270, to be designed such that it abuts a section 284, which is a section of the inner circumferential surface 270A of the engagement hole 270 where the projections 268 are not formed, and which is intersected by line L. This allows for an even more stable separation between the axial center 280 of the shaft section 262, which supports the B-gear 46, and an axial center 286 of the rotating shaft 242 of the motor 38.

[0091] One embodiment has been described above. However, the present invention is not limited to this embodiment and various other modifications compared to the embodiment described above can be implemented.

[0092] The belt winding device has a spool on which a belt, fitted by an occupant, is wound, and a motor having a rotating shaft and a first hub section arranged coaxially with the rotating shaft. The belt winding device further has a gear A, fixed to the rotating shaft, and a gear B, which meshes with gear A and is rotated by the rotating gear A, thus rotating the spool. The belt winding device also has a gearbox housing 52, which has a support section 264 for gear B, on which gear B is supported, and an engagement hole 270 that engages with the first hub section such that a mounting tolerance (an interference) exists between them, and on which the motor is fixed in a state where the first hub section is engaged with the engagement hole 270.

Claims

[1] Belt winding device (10) with: a spool (20) on which a belt fitted by an occupant is wound; a motor (38) having a rotating shaft (242) and an engaging section (58A) arranged coaxially to the rotating shaft (242); a first gear (40) which is fixed to the rotating shaft (242); a second gear (46) which meshes with the first gear (40) and which is rotated by the rotation of the first gear (40) so that the coil (20) is rotated; and a housing (52) having a support section (264) for the second gear (46) on which the second gear (46) is supported, and an engagement section (270) which engages with the engaging section (58A) such that there is a fastening tolerance between the engagement section (270) and the engaging section (58A), wherein the motor (38) is fixed to the housing (52) in a state in which the engaging section (58A) engages with the engagement section (270). wherein the engagement section (270) is an engagement hole, wherein a projection (268) is provided on an inner circumferential section of the engagement hole; and the projection (268) is deformed in a state in which the engaging section (58A) is positioned inside the engagement hole. [2] Belt winding device (10) according to claim 1, wherein the engaging section (58A) abuts a section of an inner circumferential surface (270A) of the engagement hole, wherein the projection (268) is not formed on the section of the inner circumferential surface (270A). [3] Belt winding device (10) according to claim 1, wherein the engaging section (58A) only rests against a deformed section of the projection (268).

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