SEAT BELT REEL

Abstract

A seatbelt retractor comprises a winding drum, a locking base, and a belt tensioner. The belt tensioner includes a drive wheel, a pressure vessel, and a moving element. The pressure vessel is positioned such that the opening direction of the end section is inclined orthogonally to an axial direction of the winding drum, either towards or away from the winding drum. When the belt tensioner is activated, the moving element moves the locking base, the drive wheel, and the winding drum in the axial direction of the winding drum towards the opening direction side of the end section of the pressure vessel, bringing one of the locking base, the drive wheel, and the winding drum into contact with a limiting element.

Description

REFERENCE TO RELATED REGISTRATION

[0001] This application claims the priority and benefit of Japanese patent application No. 2024-165912, which was filed on September 25, 2024, and the entire disclosure of which is hereby incorporated by reference. BACKGROUND OF THE INVENTION 1. Field of the invention

[0002] The present disclosure relates to a seat belt retractor comprising a belt tensioner for eliminating sagging of a webbing in an emergency, for example in a vehicle collision. 2. Description of the state of the art

[0003] Existing technology includes a seatbelt retractor that incorporates a belt tensioner to eliminate slack in the webbing in an emergency, such as a vehicle collision. For example, JP6752631B2 discloses a seatbelt retractor 100, which is Fig. 20 is shown.

[0004] In particular, the seat belt winder 100 includes a winding drum 120 (referred to as a "coil" in JP6752631B2) designed to wind a webbing 200, rotatably located between a pair of side walls 111 and 112 (referred to as "leg plates" in JP6752631B2) of a housing 110 (referred to as a "frame" in JP6752631B2), and a belt tensioner 130 is provided on one side wall 111.

[0005] The belt tensioner 130 comprises a drive wheel 131 (referred to as the "connecting element" in JP6752631B2) provided on an end face of the winding drum 120, a movable element 132 (referred to as the "rack" in JP6752631B2) designed to rotate the drive wheel 131 in the winding direction of the webbing 200 in a vehicle emergency, a tube (cylindrical pressure vessel) (not shown) in which the movable element 132 is housed in its normal state, and a cover element 133 that receives the drive wheel 131. The movable element 132 moves within the tube and within the cover element 133 by the pressure of gas supplied by a gas generator in a vehicle emergency to engage with the teeth of the drive wheel 131.

[0006] In the rewinder 100, a locking base 140 (referred to as "locking base" in JP6752631B2) is attached to the winding drum 120 via the drive wheel 131. In a normal state, the locking base 140 rotates together with the winding drum 120, and in a vehicle emergency, a latch 150 held by the locking base 140 engages the internal teeth formed on the cover element 133, thereby preventing the locking base 140 from rotating in the extension direction of the webbing 200.

[0007] Furthermore, in the reel 100, a movement of the locking base 140 and the drive wheel 131 to one side (in Fig. 20 the right side) in the axial direction of the winding drum 120 is restricted by the fact that a circumferential edge of the drive wheel 131 comes into contact with the side wall 111. The movement of the locking base 140 and the drive wheel 131 to the other side (left side in Fig. 20) in the axial direction of the winding drum 120 is restricted by a stepped section of a shaft section of the locking base 140, which comes into contact with a cover element 160 in which a locking mechanism is housed. SUMMARY OF THE INVENTION

[0008] In JP6752631B2, the direction of movement of the movable element 132 is not clearly described, but from Fig. Figure 20 shows that the direction of movement is perpendicular to the axial direction of the winding drum 120. However, it is not defined in this case which side in the axial direction of the winding drum 120 the locking base 140 and the drive wheel 131 move when the belt tensioner 130 is activated. That is, the sliding resistance resulting from contact with the movement limit varies depending on the direction of movement, so that a retraction force for the belt by the belt tensioner may not be stabilized.

[0009] One aspect of non-restrictive embodiments of the present disclosure relates to the provision of a seatbelt retractor that can stabilize a retraction force for a webbing by means of a belt tensioner.

[0010] According to one aspect of the present disclosure, a seat belt retractor is provided comprising: a housing comprising a pair of opposing side walls; a winding drum configured to wind up a webbing, the winding drum being located between the pair of side walls so that it is rotatable in a winding direction and an extension direction of the webbing; a locking base configured to rotate with the winding drum in a normal state and to be prevented from rotating in the extension direction in a vehicle emergency; and a belt tensioner configured to rotate the winding drum in the winding direction in an emergency.The belt tensioner comprises: a drive wheel provided on an end face of the winding drum, the drive wheel being configured to rotate in the winding direction together with the winding drum, at least during an initial phase of the emergency; a tubular pressure vessel provided on the belt tensioner-side side wall of the pair of side walls, the pressure vessel comprising an end section open at a position adjacent to the drive wheel and a base section equipped with a gas generator; and a movable element housed in the pressure vessel in a normal state, the movable element being configured to engage with the drive wheel in an emergency while being forced out of the pressure vessel by the gas generated by the gas generator in an opening direction of the end section to rotate the drive wheel in the winding direction.The pressure vessel is configured such that the opening direction of the end section is inclined orthogonally to an axial direction of the winding drum, either towards or away from the winding drum, with respect to a plane. When the belt tensioner is activated, the moving element moves the locking base, the drive wheel, and the winding drum in the axial direction of the winding drum towards the opening direction side of the end section of the pressure vessel, bringing one of the locking base, the drive wheel, and the winding drum into contact with a limiting element that is part of or attached to the housing.

[0011] According to the present disclosure, a seat belt retractor is provided which can stabilize a retraction force for a webbing by means of a belt tensioner. BRIEF DESCRIPTION OF THE DRAWINGS Fig. Figure 1 is a perspective view of a seatbelt retractor according to one embodiment; Fig. 2 is a perspective exploded view of the in Fig. 1 shown seatbelt retractor; Fig. 3 is a sectional view of the in Fig. 1 shown seatbelt retractor; Fig. 4 is a sectional view along line IV-IV in Fig. 3; Fig. 5 is a section view along line VV in Fig. 3; Fig. 6 is a sectional view along line VI-VI in Fig. 4; Fig. Figure 7 is a perspective exploded view of part of a winding drum unit; Fig. Figure 8 is a perspective exploded view of the remaining part of the winding drum unit and a synchronization gear; Fig. Figure 9 is a perspective view of a winding drum; Fig. Figure 10 is a perspective view of a drive wheel; Fig. 11 is a sectional view of a locking base; Fig. Figure 12 is a perspective exploded view of the locking base and a locking element; Fig. Figure 13 is a perspective exploded view of the locking base and locking element as seen from an opposite side; Fig. Figure 14A shows a state of a return spring when the locking element is in a non-engaged position, and Fig. Figure 14B shows a state of the return spring when the locking element is in an engaged position; Fig. Figure 15 is a sectional view of part of a seatbelt retractor according to a first modification; Fig. Figure 16 is a sectional view of part of a seatbelt retractor according to a second modification; Fig. 17 is a sectional view of a seatbelt retractor according to a third modification, as appropriate Fig. 6; Fig. Figure 18 is a sectional view of part of the seatbelt retractor according to the third modification; Fig. Figure 19 is a sectional view of part of a seatbelt retractor according to a fourth modification; and Fig. Figure 20 is a cutaway view of a conventional seatbelt retractor. DESCRIPTION OF PREFERRED EXECUTION FORMS

[0012] Fig. 1 and Fig. Figure 2 shows a seat belt retractor 1 according to one embodiment. The seat belt retractor 1 is designed to prevent a webbing 10, which forms a seat belt, from being pulled out in an emergency, for example in a vehicle collision.

[0013] In particular, the seat belt retractor 1 comprises a housing 2, a winding spring unit 1A, a winding drum unit 1B, a belt tensioner 1C and a locking unit 1D. The winding drum unit 1B comprises a winding drum 3 designed to wind up the webbing 10, and the housing 2 comprises a first side wall 21 and a second side wall 22 facing each other in an axial direction of the winding drum 3.

[0014] The winding drum 3 is positioned between the first side wall 21 and the second side wall 22 such that it can rotate in both a winding and an extension direction of the webbing 10. The housing 2 includes a rear wall 23, which is formed by sheet metal fabrication together with the first side wall 21 and the second side wall 22 and is perpendicular to the first side wall 21 and the second side wall 22. However, the rear wall 23 need not be formed by sheet metal fabrication together with the first side wall 21 and the second side wall 22, and the first side wall 21 and second side wall 22, separate from the rear wall 23, can be attached to the rear wall 23.

[0015] For the sake of simplicity, the axial direction of the winding drum 3 will be referred to as a left-right direction (the side of the first side wall 21 will be referred to as the left direction, the side of the second side wall 22 as the right direction), and the thickness direction of the back wall 23 will be referred to as a front-back direction (one side of the side walls 21 and 22 will be referred to as the forward direction, and the opposite side will be referred to as the backward direction). As in the Fig. 1 and Fig. As shown in Figure 2, one side of a direction orthogonal to the left-right direction and the front-back direction is called the upward direction, and the other side of the direction orthogonal to the left-right direction and the front-back direction is called the downward direction.

[0016] The lower and upper sections of the front faces of the first side wall 21 and the second side wall 22 of the housing 2 are connected to each other by connecting rods 24 and 25. The first side wall 21 and the second side wall 22 are each provided with openings 21a and 22a through which the winding drum 3 is inserted. In addition, the rear wall 23 is provided with an opening 23a through which the winding drum 3 is exposed.

[0017] The coil spring unit 1A is attached to the second side wall 22 of the housing 2, and the belt tensioner 1C is attached to the first side wall 21 of the housing 2. The locking unit 1D is attached to the belt tensioner 1C.

[0018] As in Fig. As shown in Figure 3, the winding drum 3 comprises a first end face 31 on one side of the first side wall 21 of the housing 2 and a second end face 32 on one side of the second side wall 22 of the housing 2. In the present embodiment, the winding drum 3 comprises a shaft section 33 that projects to the right from the second end face 32, and the shaft section 33 is rotatably mounted on the winding spring assembly 1A. However, a torsion bar 4A, to be described later, can penetrate the winding drum 3, and a right end section of the torsion bar 4A can be rotatably mounted on the winding spring assembly 1A. Since one embodiment of the winding spring assembly 1A is known, a detailed description of it is omitted.

[0019] As in the Fig. 7 and Fig. As shown in Figure 8, the winding drum unit 1B comprises, in addition to the winding drum 3, a bushing 3A, a bearing 3B, the torsion rod 4A, an impact energy-absorbing wire 4B, a stop element 4C, a drive wheel 5, a locking base 6, a return spring 9A, and a pivot shaft 9B. The drive wheel 5 is also a component of the belt tensioner 1C. In other words, the drive wheel 5 is also included in the belt tensioner 1C.

[0020] The bushing 3A and the bearing 3B are emergency devices that ensure the winding drum 3 rotates smoothly even if its relative position to the housing 2 shifts during a vehicle emergency. As shown in Fig. As shown in Figure 3, the bushing 3A is attached to a right end section of the winding drum 3, which is positioned in the opening 22a of the second side wall 22, and the bearing 3B is attached to a left end section of the winding drum 3, which is positioned in the opening 21a of the first side wall 21. Furthermore, the bearing 3B comprises a folded section 3Ba (see Figure 3). Fig. 7), which is folded back to an inside of the left end section of the winding drum 3 and is designed to slide with the drive wheel 5 when the winding drum 3 and the locking base 6 are rotated relative to each other.

[0021] The winding drum 3 has a central hole 30 that extends along a central axis of the winding drum 3. In the present embodiment, the central hole 30 is provided with a bottom and is open only towards the first end face 31. However, in a case where the torsion bar 4A penetrates the winding drum 3 as described above, the central hole 30 can be open not only in the first end face 31, but also in the second end face 32.

[0022] The torsion bar 4A is inserted into the central hole 30 of the winding drum 3. The locking base 6 described above is arranged such that it faces the first end face 31 of the winding drum 3. The torsion bar 4A comprises one end face opposite the locking base 6, which is connected to the winding drum 3 without being rotatable relative to the winding drum 3, and the other end face, which is connected to the locking base 6 without being rotatable relative to the locking base 6. Therefore, in a normal state, the locking base 6 rotates together with the winding drum 3.

[0023] More precisely, the torsion rod 4A includes spline-shaped coupling sections 41 and 42 on one end face and the other end face, respectively. The bottom of the central hole 30 of the winding drum 3 includes a spline-shaped recess for coupling with the coupling section 41, and the coupling section 41 is fitted into the recess.

[0024] The torsion bar 4A is designed to be plastically deformed when the pull-out force of the webbing 10 exceeds a predetermined value, while the locking base 6 is prevented from rotating in the pull-out direction in order to absorb the impact energy and simultaneously allow relative rotation between the winding drum 3 and the locking base 6. In other words, in an initial phase of the vehicle emergency, before the torsion bar 4A is plastically deformed, the locking base 6 and the drive wheel 5 attached to the locking base 6 rotate together with the winding drum 3 in the winding direction of the webbing 10.

[0025] The impact energy-absorbing wire 4B is designed to absorb impact energy in an initial phase when the winding drum 3 and the locking base 6 rotate relative to each other. In the present embodiment, the winding drum 3 is, as shown in Fig. Figure 9 shows the winding drum 3 with two slots 35 open in the first end face 31. In the present embodiment, each slot 35 has a groove shape that is recessed obliquely from an outer circumferential surface of the winding drum 3. However, the slot 35 can also be a hole extending in the axial direction of the winding drum 3. The number of slots 35 can be one.

[0026] The impact energy absorbing wire 4B is housed in one of the slots 35 in a state in which a head section 43 (see Fig. 7) protrudes from the opening 36 of the slot 35. The impact energy-absorbing wire 4B is designed to be pulled out of the opening 36 while plastically deformed when the winding drum 3 and the locking base 6 are rotated relative to each other to absorb the impact energy. The impact energy-absorbing wire 4B can be omitted.

[0027] The stop element 4C defines a permissible amount of relative rotation between the winding drum 3 and the locking base 6 in a case where the torsion bar 4A absorbs the impact energy. The stop element 4C is held in the center hole 30 of the winding drum 3 without being rotatable relative to the winding drum 3, and is movable in the left-right direction.

[0028] As in Fig. As shown in Figure 7, the stop element 4C has a tubular shape through which the torsion rod 4A is inserted. The stop element 4C is formed with an internal thread 47 on an inner circumferential surface of the stop element 4C.

[0029] In the present embodiment, the stop element 4C comprises an annular section 45 and three claw sections 46 projecting from the annular section 45 in the right direction. The central hole 30 of the winding drum 3, on the other hand, comprises three guide grooves 34. Since the three claw sections 46 are each fitted into the three guide grooves 34, the stop element 4C is held by the winding drum 3 without being rotatable relative to the winding drum 3 and is thus movable in the left-right direction. However, instead of the stop element 4C comprising the claw sections 46, the cross-sectional shape of an outer form of the stop element 4C and the cross-sectional shape of a left end section of the central hole 30 of the winding drum 3 can also be polygonal.

[0030] As in the Fig. 3 and Fig. As shown in Figure 8, the locking base 6 has an external threaded screw 73 onto which the internal threaded screw 47 of the stop element 4C is screwed. Furthermore, the drive wheel 5 is attached to the locking base 6 in an annular shape. In other words, the drive wheel 5 is provided via the locking base 6 on an end face (in the present embodiment, the left end face) of the winding drum 3.

[0031] In the present embodiment, as in Fig. Figure 3 shows the stop element 4C during the relative rotation of the winding drum 3 and the locking base 6 from a position in which the stop element 4C is separated from the drive wheel 5 to a position in which the stop element 4C comes into contact with the drive wheel 5, thereby limiting the relative rotation between the winding drum 3 and the locking base 6 to a predetermined amount.

[0032] As in the Fig. 8 and Fig. As shown in Figure 10, the drive wheel 5 comprises a main body section 51 with a fitting hole having a hexagonal cross-section, a plurality of engagement teeth 52 formed on an outer circumferential surface of the main body section 51, an annular flange section 53 projecting radially outward from the main body section 51 on a right side of the engagement teeth 52, and an annular rib 55 projecting to the right of the flange section 53. An annular flange section 56 projects from an inner circumferential surface of the main body section 51. The flange section 56 is a part that comes into contact with the stop element 4C.

[0033] As in Fig. As shown in Figure 3, the flange section 53 of the drive wheel 5 faces the first end face 31 of the winding drum 3. The flange section 53 comprises a plurality of (in the present embodiment six, as shown in Figure 3). Fig. 10 shown) Holding sections 54. The head section 43 of the impact energy absorbing wire 4B described above is attached to one of the holding sections 54.

[0034] In the present embodiment, the retaining sections 54 are radially outwardly opening grooves. The head section 43 of the impact energy absorbing wire 4B comprises an anti-lifting section 44 (see Fig. 7), which is located on one side of the flange section 53 opposite the winding drum 3 and has a diameter larger than the width of the groove forming the retaining section 54. However, the retaining sections 54 can also be holes that penetrate the flange section 53.

[0035] As in Fig. As shown in Figure 3, in the present embodiment the drive wheel 5 comes into contact with the first end face 31 of the winding drum 3 via the rib 55. The impact energy-absorbing wire 4B is pulled out of the opening 36 of the slot 35 while it is wound around the rib 55. When the winding drum 3 and the locking base 6 are rotated relative to each other, the winding drum 3 and the drive wheel 5 are rotated relative to each other, while the rib 55 of the drive wheel 5 comes into contact with the first end face 31 of the winding drum 3 in the axial direction of the winding drum 3, and while an outer circumference of the flange section 53 of the drive wheel 5 comes into contact with the folded section 3Ba of the bearing 3B attached to the winding drum 3 in a radial direction of the winding drum 3.

[0036] The belt tensioner 1C rotates the winding drum 3 in the winding direction of the webbing 10 via the locking base 6 and the torsion bar 4A by rotating the drive wheel 5 in the winding direction of the webbing 10 in a vehicle emergency. As shown in the Fig. As shown in Figures 2 to 4, the belt tensioner 1C comprises a cover element 11 attached to the first side wall 21 of the housing 2, a tubular pressure vessel 12 extending in a bending motion from the cover element 11, and a movable element 13 which is housed in the pressure vessel 12 in the normal state.

[0037] As in Fig. As shown in Figure 6, the pressure vessel 12 is provided at the cover element 11 and the first side wall 21 on the belt tensioner side 1C. The cover element 11 accommodates the drive wheel 5 and an end section 12a of the pressure vessel 12. The end section 12a of the pressure vessel 12 is open at a point next to the drive wheel 5, and a gas generator 18 is provided in a base section 12b of the pressure vessel 12.

[0038] In the present embodiment, the pressure vessel 12 is configured such that the opening direction of the end section 12a is inclined towards the winding drum 3 in a plane orthogonal to the axial direction of the winding drum 3. Therefore, the flange section 53 of the drive wheel 5 is positioned on the opening direction side of the end section 12a of the pressure vessel 12 in the axial direction of the winding drum 3 with respect to the engagement teeth 52. For example, the angle of inclination of the opening direction of the end section 12a with respect to the plane orthogonal to the axial direction of the winding drum 3 is in a range of 5 to 15 degrees.

[0039] In the present embodiment, the movable element 13 has a rod shape and is plastically deformed by the engagement of the engagement teeth 52 of the drive wheel 5. However, the movable element 13 can be realized by a plurality of split bodies (for example, spheres) arranged at the same distance as the engagement teeth 52 of the drive wheel 5.

[0040] In a vehicle emergency, the movable element 13 engages with the engagement teeth 52 of the drive wheel 5. It is then forced out of the pressure vessel 12 by the gas generated by the gas generator 18 in the opening direction of the end section 12a, thus rotating the drive wheel 5 in the winding direction of the webbing 10. As the drive wheel 5 rotates, the locking base 6, the torsion bar 4A, and the winding drum 3 also rotate. Once the belt tensioner 1C is activated, the pressure of the gas in the pressure vessel 12 prevents the movable element 13 from being pushed back into the pressure vessel 12, thereby preventing the drive wheel 5 from rotating in the extension direction of the webbing 10.

[0041] As in the Fig. 2 and Fig. As shown in Figure 5, the cover element 11 is provided with an opening 11a through which the locking base 6 is inserted, and the opening 11a has internal teeth 11b formed on a circumferential edge of the opening 11a. The locking base 6 also includes a latch 61 designed to engage with the internal teeth 11b. The latch 61 engages with the internal teeth 11b to prevent the locking base 6 from rotating in the extension direction of the webbing 10 in a vehicle emergency.

[0042] As in the Fig. As shown in Figures 11 to 13, the locking base 6 comprises a first base element 7, to which the drive wheel 5 is attached, and a second base element 8, which is attached to the first base element 7 on one side of the first base element 7 opposite the winding drum 3, without being rotatable relative to the first base element 7. The pawl 61 is held between the first base element 7 and the second base element 8.

[0043] More precisely, the first basic element 7 comprises a disk-shaped first main body section 71 and a projecting section 72 that extends from the first main body section 71 in the right direction. As in Fig. As shown in Figure 3, the drive wheel 5 is arranged between the first main body section 71 and the first end face 31 of the winding drum 3, and the projecting section 72 penetrates the drive wheel 5. A proximal section of the projecting section 72 is configured to have a hexagonal cross-sectional shape, and by fitting the proximal section into the fitting hole of the main body section 51 of the drive wheel 5, which also has a hexagonal cross-sectional shape, the drive wheel 5 is fastened to the first base element 7 without being rotatable relative to the first base element 7. The externally threaded screw 73 described above is formed on the outer circumferential surface of the distal end face of the projecting section 72.

[0044] The first base element 7 comprises a first recess 74, which is set back from a distal end face of the projecting section 72, and a second recess 75, which is coaxial with the first recess 74 and is set back from a surface of the first main body section 71 on a side opposite the drive wheel 5. The first recess 74 is a spline-shaped recess for coupling with the coupling section 42 of the torsion rod 4A, and the coupling section 42 is fitted into the first recess 74. In the present embodiment, the second recess 75 has a circular cross-sectional shape. In the present embodiment, the first base element 7 comprises a partition 76 that separates the first recess 74 and the second recess 75 from each other. That is to say, the first recess 74 and the second recess 75 are provided with a bottom.

[0045] The second base element 8 comprises a plate-shaped second main body section 81 that overlaps the first main body section 71, and a fitting projection 82 that projects from the second main body section 81 in the right-hand direction. In the present embodiment, the second main body section 81 comprises three concave engagement sections 87, and the second base element 8 is attached to the first base element 7 by the engagement of three convex engagement sections 79 provided on the first main body section 71 with the respective concave engagement sections 87, without being rotatable relative to the first base element 7. The fitting projection 82 has a circular cross-section and is fitted into the second recess 75.However, the second recess 75 and the fitting projection 82 can also have a non-circular cross-sectional shape, and by fitting the fitting projection 82 into the second recess 75, the second base element 8 can be attached to the first base element 7 without being rotatable relative to the first base element 7. In this case, the concave engagement sections 87 and the convex engagement sections 79 can be omitted.

[0046] In the present embodiment, the second main body section 81 of the second base element 8 comprises three crimp projections 85 projecting in the right direction, while the first main body section 71 of the first base element 7 is provided with three through-holes 77 through which the crimp projections 85 are inserted. On a side of the first main body section 71 opposite the second main body section 81, concave crimp sections 78 are formed which are coaxial with the through-holes 77 and have a larger diameter than the through-holes 77. A portion of each crimp projection 85 that projects from the through-hole 77 is crimped to have a larger diameter than the through-hole 77 in the concave crimp section 78 and to have an outer diameter that is substantially equal to the inner diameter of the concave crimp section 78 (in the Fig. 12 and Fig. 13 shows the crimp protrusion 85 in a form before crimping).

[0047] The latch 61 comprises an essentially arc-shaped and plate-shaped main body section 62, which is held by the first main body section 71 of the first base element 7 and by the second main body section 81 of the second base element 8, a plurality of (in the illustrated example three) engagement teeth 63, which are formed on an outer surface of the main body section 62 and are designed to engage with the internal teeth 11b described above, and an actuating shaft 64, which projects from the main body section 62 in the left direction.

[0048] The second main body section 81 of the second base element 8 includes a pin 84 that projects in the left direction. The return spring 9A described above has, as in Fig. Figure 8 shows a spring essentially in an arc shape, and the return spring 9A comprises one end that engages with the actuating shaft 64 of the pawl 61, and the other end that engages with the pin 84. The return spring 9A is designed to return the pawl 61 to a position that is Fig. to maintain the non-intervention position shown in 14A.

[0049] The second base element 8 is provided with an engagement hole 83 that is coaxial with the fitting projection 82 and opens in the left-hand direction. In the present embodiment, the engagement hole 83 penetrates the second base element 8 and also opens in the right-hand direction. The engagement hole 83 has a hexagonal cross-sectional shape.

[0050] The latch 61 is actuated by a synchronous wheel 14 (see Fig. 2 and Fig. 8). As in Fig. As shown in Figure 2, the locking unit 1D comprises a cover element 17 in which the synchronizing wheel 14 and a vehicle sensor 16 are housed. The synchronizing wheel 14 includes a belt sensor 15. The belt sensor 15 is designed to be activated when the belt 10 is rapidly extended, thus preventing the synchronizing wheel 14 from rotating in the extension direction. The vehicle sensor 16 is designed to be activated when the vehicle's acceleration changes sharply, thus preventing the synchronizing wheel 14 from rotating in the extension direction.

[0051] In a case where the synchronizing wheel 14 is prevented from rotating in the extension direction, the locking base 6 together with the winding drum 3 is rotated relative to the synchronizing wheel 14, and the actuating shaft 64 of the pawl 61 is inserted into a guide hole 14a (see Fig. 8) of the synchronizing wheel 14 is actuated, causing the pawl 61 to disengage from the in Fig. 14A non-intervention position in a Fig. The intervention position shown in 14B is moved.

[0052] As in Fig. As shown in Figure 8, the rotary shaft 9B described above comprises a rod-shaped main body section 91 and an arm 92 extending radially outward from the main body section 91. A right-hand side section of the main body section 91 has a hexagonal cross-sectional shape, and the right-hand side section is fitted into and engages with the engagement hole 83 of the second base element 8. The arm 92 serves to retain the return spring 9A, and a hook 93 provided at the distal end of the arm 92 engages in an engagement hole 86 provided in the second main body section 81 of the second base element 8. As shown in Fig. As shown in Figure 3, a left side section of the rotary shaft 9B projects into the synchronizing wheel 14 and is rotatably mounted by the cover element 17 of the locking unit 1D.

[0053] Next, an effect is described that results from the inclination of the opening direction of the end section 12a of the pressure vessel 12. When the belt tensioner 1C is activated, the movable element 13, which is pushed out of the pressure vessel 12 in the opening direction of the end section 12a, comes into contact with the flange section 53 of the drive wheel 5 and pushes the flange section 53 in the axial direction of the winding drum 3 towards the opening direction side of the end section 12a of the pressure vessel 12, i.e., to the right. The movable element 13 also comes into contact with the bearing 3B, which is arranged radially outside the flange section 53, and pushes the first end face 31 of the winding drum 3 over the bearing 3B to the right.This causes the drive wheel 5, the locking base 6 and the winding drum 3 to be moved to the right by the movable element 13, so that the right end section of the winding drum 3 comes into contact with the second side wall 22 of the housing 2 via the socket 3A.

[0054] That is, the second side wall 22, which is part of the housing 2, serves as a limiting element designed to restrict movement of the drive wheel 5, the locking base 6, and the winding drum 3 in the axial direction of the winding drum 3. The bushing 3A is a friction-reducing element arranged between the winding drum 3 and the second side wall 22 and designed to reduce sliding resistance due to contact between the winding drum 3 and the second side wall 22. The friction-reducing element simply needs to have better sliding properties than in a case where the winding drum 3 and the second side wall 22 slide against each other. In a case where the housing 2 and the winding drum 3 are made of metal (e.g., steel or an aluminum alloy), as in the present embodiment, the bushing 3A is made of a material (e.g.,Fluoropolymer, polyacetal, polypropylene or the like), which has better lubricity than in a case where metals slide against each other.

[0055] As described above, in the seatbelt retractor 1 according to the present embodiment, the movable element 13, when the belt tensioner 1C is activated, brings the winding drum 3 into contact with the limiting element, which is the second side wall 22 of the housing 2, via the bushing 3A, thus defining movement restriction states of the locking base 6, the drive wheel 5, and the winding drum 3 in the axial direction of the winding drum 3. Therefore, a retraction force for the webbing 10 can be stabilized by the belt tensioner 1C.

[0056] Furthermore, in the present embodiment, the movable element 13 presses on the flange section 53 of the drive wheel 5 and also presses on the first end face 31 of the winding drum 3 via the bearing 3B. Thus, by means of a pressure force of the movable element 13 on the flange section 53 of the drive wheel 5 and the first end face 31 of the winding drum 3, the winding drum 3 can be brought into contact with the limiting element via the bushing 3A.

[0057] Furthermore, in the present embodiment, the limiting element is the second side wall 22 of the housing 2, and thus the existing component serves as the limiting element. Therefore, it is not necessary to add a new component as the limiting element. Moreover, the housing 2, which has sufficient strength, can be used as the limiting element.

[0058] Furthermore, in the present embodiment, the bushing 3A is used as the friction-reducing element, thereby reducing the friction between the winding drum 3 and the limiting element when the belt tensioner 1C is activated. This ensures a sufficient retraction force for the belt 10 by the belt tensioner 1C. If the friction-reducing element is the bushing 3A, it can also be designed in a simplified manner. <modifikationen>

[0059] The foregoing description of exemplary embodiments of the present invention is provided for illustrative and descriptive purposes. It does not claim to be exhaustive and does not limit the invention to the forms disclosed. Naturally, those skilled in the art will think of many modifications and variations. The embodiments have been selected and described to best explain the principles of the invention and its practical applications, so that other skilled persons may understand the invention for different embodiments and with the various modifications suitable for the respective intended use. The scope of the invention is defined by the following claims and their equivalents.

[0060] For example, the locking base 6 does not need to hold the latch 61 and can be a ratchet mechanism with which the latch held by the housing 2 engages.

[0061] The belt tensioner 1C can be located on one side of the winding drum 3 opposite the locking base 6, i.e., on the second side wall 22 of the housing 2. In this case, the drive wheel 5 can be provided via a coupling on the right end face of the winding drum 3. The coupling, provided as described above, is designed to allow the drive wheel 5 to rotate relative to the winding drum 3 in a normal state and to rotate integrally with the winding drum 3 in a vehicle emergency. That is, at least in the initial phase of a vehicle emergency, the drive wheel 5 can rotate together with the winding drum 3 in the winding direction of the webbing 10.

[0062] Even in the case where the belt tensioner 1C is provided on the first side wall 21 as in the embodiment above, a coupling can be provided between the locking base 6 and the drive wheel 5, so that the drive wheel 5 rotates relative to the locking base 6 in a normal state and the drive wheel 5 rotates integrally with the locking base 6 in the vehicle emergency.

[0063] In contrast to the embodiment described above, the belt tensioner 1C can be provided inside the housing 2 (between the first side wall 21 and the second side wall 22). For example, the cover element 11 of the belt tensioner 1C can be attached to an inner surface of the first side wall 21, and internal teeth can be provided on the first side wall 21 that engage with the latch 61.

[0064] The drive wheel 5 can function without the flange section 53, and when the belt tensioner 1C is activated, the movable element 13 can come into contact with the first end face 31 of the winding drum 3 and press the first end face 31 in the axial direction of the winding drum 3 towards the opening direction side of the end section 12a of the pressure vessel 12, i.e., to the right side. In this configuration, the winding drum 3 can be brought into contact with the second side wall 22, which is the limiting element, by a pressure force of the movable element 13 on the first end face 31 of the winding drum 3.

[0065] As with a seatbelt retractor according to an initial modification, which in Fig. As shown in Figure 15, the winding drum 3 can have a flanged section 37 at its left end section, located on the left side relative to the first side wall 21 and extending radially outwards, and a bushing 3C can be attached to the opening 21a of the first side wall 21. The flanged section 37 faces a circumferential section of the opening 21a of the first side wall 21 in the left-right direction. That is, in the first modification, the first side wall 21, which is part of the housing 2, is the limiting element, and the bushing 3C is the friction-reducing element arranged between the winding drum 3 and the limiting element.

[0066] Alternatively, as with a seatbelt retractor according to a second modification, the one in Fig. As shown in Figure 16, the drive wheel 5 has a flange section 57 extending radially outwards, such that it faces a circumferential section of the opening 21a of the first side wall 21 in the left-right direction, and the bushing 3C can be attached to the opening 21a of the first side wall 21. That is, in the second modification, the first side wall 21, which is part of the housing 2, is the limiting element, and the bushing 3C is the friction-reducing element arranged between the drive wheel 5 and the limiting element.

[0067] In Fig. 16. When the belt tensioner 1C is activated, the movable element 13, which is pushed out of the pressure vessel 12 in the opening direction of the end section 12a, comes into contact with the flange section 53 and the flange section 57 of the drive wheel 5 and pushes the flange section 53 and the flange section 57 in the axial direction of the winding drum 3 towards the opening direction side of the end section 12a of the pressure vessel 12, i.e., to the right side. This causes the drive wheel 5, the locking base 6, and the winding drum 3 to be moved to the right by the movable element 13, so that the flange section 57 comes into contact with the first side wall 21 via the bushing 3C.

[0068] As with a seatbelt retractor according to a third modification, which is in Fig. As shown in Figure 17, the pressure vessel 12 can be provided such that the opening direction of the end section 12a is inclined relative to the winding drum 3 with respect to a plane that is orthogonal to the axial direction of the winding drum 3, i.e. inclined to the left.

[0069] In this case, as in Fig. 18 shows an outer circumferential edge located on the radially outer side of the first main body section 71 of the first base element 7 of the locking base 6 relative to the preceding section 72, as a flange section provided on the opening direction side of the end section 12a of the pressure vessel 12 relative to the engagement teeth 52 of the drive wheel 5 in the axial direction of the winding drum 3, i.e., provided on the left side.

[0070] A portion located on the radially outer side of the first main body section 71 of the first base element 7 of the locking base 6, relative to the preceding section 72, faces a circumferential edge of the opening 11a of the cover element 11 of the belt tensioner 1C in the left-right direction. That is, the cover element 11 serves as the limiting element designed to restrict movement of the drive wheel 5, the locking base 6, and the winding drum 3 in the axial direction of the winding drum 3.

[0071] Furthermore, a 3D coating is provided on the right surface of the circumferential edge of the opening 11a of the cover element 11 as a friction reduction element, designed to reduce sliding resistance due to contact between the locking base 6 and the cover element 11. The 3D coating is made of a material (e.g., a material containing fluoropolymer, molybdenum disulfide, or graphite) with excellent lubricity.

[0072] In Fig. 18. When the belt tensioner 1C is activated, the movable element 13, which is pushed out of the pressure vessel 12 in the opening direction of the end section 12a, comes into contact with the outer circumferential edge (flange section) of the first main body section 71 of the first base element 7 of the locking base 6 and pushes the outer circumferential edge of the first main body section 71 in the axial direction of the winding drum 3 towards the opening direction side of the end section 12a of the pressure vessel 12, i.e., to the left. This causes the drive wheel 5, the locking base 6, and the winding drum 3 to be moved to the left by the movable element 13, so that the outer circumferential edge of the first main body section 71 comes into contact with the cover element 11 via the coating 3D.

[0073] That means also in the third in Fig. In the modification shown in Figure 18, as in the embodiment above, movement restriction states of the locking base 6, the drive wheel 5, and the winding drum 3 are defined in the axial direction of the winding drum 3. Therefore, a retraction force for the belt 10 can be stabilized by the belt tensioner 1C.

[0074] Furthermore, in the third modification, the movable element 13 presses on the outer circumferential edge of the first main body section 71 of the first base element 7. By means of a pressure force of the movable element 13 on the outer circumferential edge of the first main body section 71, the outer circumferential edge of the first main body section 71 can thus be brought into contact with the cover element 11 (boundary element) via the 3D coating.

[0075] Furthermore, in the third modification, the limiting element is the cover element 11, and thus the existing component serves as the limiting element. Therefore, it is not necessary to add a new component as the limiting element. Moreover, the cover element 11, which has sufficient strength, can be used as the limiting element.

[0076] Furthermore, in the third modification, the 3D coating is used as the friction reduction element, thus reducing friction between the locking base 6 and the limiting element when the belt tensioner 1C is activated. This ensures sufficient retraction force for the webbing 10 by the belt tensioner 1C. If the 3D coating serves as the friction reduction element, its design can also be simplified.

[0077] In a case where the pressure vessel 12 is provided such that the opening direction of the end section 12a is inclined to the left, as in a seatbelt retractor according to a fourth modification described in Fig. As shown in Figure 19, the winding drum 3 can have a flanged section 38 at its left end section, which is located on the right side relative to the first side wall 21 and extends radially outwards, and a bushing 3E can be attached to the opening 21a of the first side wall 21. The flanged section 38 faces a circumferential section of the opening 21a of the first side wall 21 in the left-right direction. That is, in the fourth modification, the first side wall 21, which is part of the housing 2, is the limiting element, and the bushing 3E is the friction-reducing element arranged between the winding drum 3 and the limiting element.

[0078] In the embodiment above, the bushing 3A can be provided on the second side wall 22 instead of on the right end section of the winding drum 3. In the first modification, the bushing 3C can be provided on the left end section of the winding drum 3 instead of on the first side wall 21. In the second modification, the bushing 3C can be provided on the drive wheel 5 instead of on the first side wall 21. In the third modification, the coating 3D can be provided on a surface of the first main body section 71 of the first base element 7 of the locking base 6 instead of on a surface of the cover element 11. In the fourth modification, the bushing 3E can be provided on the left end section of the winding drum 3 instead of on the first side wall 21. Furthermore, a coating can be used instead of a bushing, or a bushing instead of a coating.

[0079] When the belt tensioner 1C is activated, the movable element 13 can be configured to move the drive wheel 5, the locking base 6 and the winding drum 3 in the axial direction of the end section 12a of the pressure vessel 12 only by means of a frictional force in the direction of the opening direction side of the end section 12a of the pressure vessel 12, without coming into contact with any parts other than the engagement teeth 52 of the drive wheel 5. <Overview>

[0080] The first aspect of the present disclosure is a seat belt retractor comprising: a housing comprising a pair of opposing side walls; a winding drum configured to wind up a webbing, the winding drum being located between the pair of side walls so that it is rotatable in a winding direction and an extension direction of the webbing; a locking base configured to rotate with the winding drum in a normal state and to be prevented from rotating in the extension direction in a vehicle emergency; and a belt tensioner configured to rotate the winding drum in the winding direction in an emergency.The belt tensioner comprises: a drive wheel provided on an end face of the winding drum, the drive wheel being configured to rotate in the winding direction together with the winding drum, at least during an initial phase of the emergency; a tubular pressure vessel provided on the belt tensioner-side side wall of the pair of side walls, the pressure vessel comprising an end section open at a position adjacent to the drive wheel and a base section equipped with a gas generator; and a movable element housed in the pressure vessel in a normal state, the movable element being configured to engage with the drive wheel in an emergency while being forced out of the pressure vessel by the gas generated by the gas generator in an opening direction of the end section to rotate the drive wheel in the winding direction.The pressure vessel is configured such that the opening direction of the end section is inclined orthogonally to an axial direction of the winding drum, either towards or away from the winding drum, with respect to a plane. When the belt tensioner is activated, the moving element moves the locking base, the drive wheel, and the winding drum in the axial direction of the winding drum towards the opening direction side of the end section of the pressure vessel, bringing one of the locking base, the drive wheel, and the winding drum into contact with a limiting element that is part of or attached to the housing.

[0081] According to the above embodiment, when the belt tensioner is activated, the movable element brings one of the locking bases, the drive wheel, and the winding drum into contact with the limiting element, thereby defining movement limit states of the locking base, the drive wheel, and the winding drum in the axial direction of the winding drum. Therefore, the retraction force for the belt can be stabilized by the belt tensioner.

[0082] As a second aspect, the drive wheel, according to the first aspect, can have engagement teeth for engagement with the moving element and a flange section provided on the opening direction side of the end section of the pressure vessel in the axial direction of the winding drum with respect to the engagement teeth, and when the belt tensioner is activated, the moving element can come into contact with the flange section and press the flange section in the axial direction of the winding drum towards the opening direction side of the end section of the pressure vessel.

[0083] According to the above design, a pressure force of the movable element on the flange section of the drive wheel can bring one of the locking base, the drive wheel and the winding drum into contact with the limiting element.

[0084] As a third aspect, in addition to the first or second aspect, when the belt tensioner is activated, the moving element can come into contact with an end face of the winding drum and press the end face in the axial direction of the end section of the pressure vessel.

[0085] According to the above embodiment, a pressure force of the movable element on the end face of the winding drum can cause one of the locking base, the drive wheel and the winding drum to come into contact with the limiting element.

[0086] As a fourth aspect, in accordance with the first or second aspect, the drive wheel can be provided via the locking base on an end face of the winding drum and include engagement teeth for engaging with the moving element. The locking base can include a flange section provided on the opening-direction side of the end section of the pressure vessel in the axial direction of the winding drum with respect to the engagement teeth. When the belt tensioner is activated, the moving element can come into contact with the flange section and press the flange section in the axial direction of the winding drum towards the opening-direction side of the end section of the pressure vessel. According to the above embodiment, a compressive force of the moving element on the flange section of the locking base can bring the locking base, the drive wheel, and the winding drum into contact with the limiting element.

[0087] As a fifth aspect, in accordance with one of the first four aspects, the limiting element can be one of the two side walls of the housing. According to the design described above, the existing component serves as the limiting element. Therefore, it is not necessary to add a new component as the limiting element. Furthermore, the housing itself, which possesses sufficient strength, can be used as the limiting element.

[0088] As a sixth aspect, in accordance with one of the first four aspects, the belt tensioner can include a cover element that accommodates the drive wheel and the end section of the pressure vessel and is attached to the housing, and the limiting element can be the cover element. According to the above embodiment, the existing component serves as the limiting element. Therefore, it is not necessary to add a new component as the limiting element. Furthermore, the cover element, which has sufficient strength, can be used as the limiting element.

[0089] As a seventh aspect, the seatbelt retractor, according to one of the first to sixth aspects, can further include a friction reduction element designed to reduce sliding resistance due to contact between the limiting element and one of the locking base, the drive wheel, and the winding drum. According to the above embodiment, friction between the limiting element and one of the locking base, the drive wheel, and the winding drum is reduced when the belt tensioner is activated. Thus, a sufficient retraction force for the webbing by the belt tensioner can be ensured.

[0090] As an eighth aspect, in accordance with the seventh aspect, the friction-reducing element can be a bushing arranged between the limiting element and one of the locking base, the drive wheel, and the winding drum, or a coating on a surface of the locking base, the drive wheel, the winding drum, or the limiting element. According to the above embodiment, the friction-reducing element can be designed in a simplified manner. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] JP 2024-165912

[0001] JP 6752631B2 [0003, 0004, 0005, 0006, 0008]< / modifikationen>

Claims

[1] Seat belt retractor, comprising: a housing comprising a pair of opposing side walls; a winding drum designed to wind up a webbing, wherein the winding drum is housed between the pair of side walls in such a way that it can be rotated in a winding direction and an extension direction of the webbing; a locking base designed to rotate with the winding drum in a normal state and to be prevented from rotating in the extension direction in a vehicle emergency; and a belt tensioner designed to rotate the winding drum in the winding direction in an emergency, whereby the seatbelt tensioner includes a drive wheel provided on an end face of the winding drum, wherein the drive wheel is designed to rotate together with the winding drum in the winding direction, at least in an initial phase of the emergency, a tubular pressure vessel provided on the belt tensioner-side side wall of the pair of side walls, the pressure vessel comprising an end section open at a position next to the drive wheel and a base section fitted with a gas generator, and a movable element which in a normal state is housed in the pressure vessel, wherein the movable element is designed to engage with the drive wheel in an emergency while being forced out of the pressure vessel by the gas generated by the gas generator in an opening direction of the end section in order to rotate the drive wheel in the winding direction, the pressure vessel is provided in such a way that the opening direction of the end section is inclined orthogonally to an axial direction of the winding drum towards or away from the winding drum with respect to a plane, and When the belt tensioner is activated, the moving element moves the locking base, the drive wheel and the winding drum in the axial direction of the winding drum towards the opening direction side of the end section of the pressure vessel and brings one of the locking base, the drive wheel and the winding drum into contact with a limiting element that is part of or attached to the housing. [2] Seat belt retractor according to claim 1, wherein the drive wheel comprises engagement teeth for engagement with the moving element, and a flange section provided on the opening direction side of the end section of the pressure vessel in the axial direction of the winding drum with respect to the engagement teeth, and When the belt tensioner is activated, the moving element comes into contact with the flange section and pushes the flange section in the axial direction of the winding drum towards the opening direction side of the end section of the pressure vessel. [3] Seat belt retractor according to claim 1 or 2, wherein When the belt tensioner is activated, the moving element comes into contact with an end face of the winding drum and presses the end face in the axial direction of the winding drum towards the opening direction side of the end section of the pressure vessel. [4] Seatbelt retractor according to claim 1 or 2, wherein the drive wheel is provided via the locking base on an end face of the winding drum and includes engagement teeth for engagement with the moving element, the locking base comprises a flange section provided on the opening direction side of the end section of the pressure vessel in the axial direction of the winding drum with respect to the engagement teeth, and When the belt tensioner is activated, the moving element comes into contact with the flange section and pushes the flange section in the axial direction of the winding drum towards the opening direction side of the end section of the pressure vessel. [5] Seat belt retractor according to one of claims 1 to 4, wherein the limiting element is one of the two side walls of the housing. [6] Seat belt retractor according to any one of claims 1 to 4, wherein the belt tensioner includes a cover element that accommodates the drive wheel and the end section of the pressure vessel and is attached to the housing, and The boundary element is the cover element. [7] Seat belt retractor according to any one of claims 1 to 6, further comprising a friction reduction element designed to reduce sliding resistance due to contact between the limiting element and the locking base, the drive wheel and the winding drum. [8] Seat belt retractor according to claim 7, wherein The friction reduction element is a bushing arranged between the limiting element and one of the locking base, drive wheel and winding drum, or a coating on a surface of the locking base, drive wheel, winding drum or limiting element.

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