JP4272574B2 - Webbing take-up device - Google Patents

Description

  The present invention relates to a webbing take-up device, and more particularly to a webbing take-up device capable of winding a webbing by rotating a take-up shaft by a motor.

  The occupant restraint seat belt device includes a webbing take-up device. In this webbing take-up device, a so-called tension reducer mechanism for reducing or eliminating excessive pressure feeling when the webbing is mounted, and a webbing belt is wound around a take-up shaft by a certain amount in a vehicle sudden deceleration state or the like. There are some which provide a pretensioner mechanism that eliminates a slight slack called `` slack '' and the like and increases the restraining force of the occupant's body by the webbing belt, and holds the occupant's body more securely. A so-called motor retractor in which each function is performed by a motor is known (see Patent Document 1 and Patent Document 2 as examples).

  In this type of motor retractor, for example, not only can the function of a tension reducer and pretensioner be exhibited as described above, but also it is possible to assist in winding and pulling out the webbing when wearing a normal webbing, Very useful.

  Further, particularly in recent years, in the motor retractor as described above, the distance to other vehicles and obstacles in front is detected by a forward monitoring device such as a distance sensor, and the distance to the vehicle and obstacles ahead is a constant value. If it is less than that, a configuration is considered in which the motor is operated and the winding shaft is rotated in the winding direction by the rotational force of the motor.

  By the way, in the case of the motor retractor as described above, in order to prevent the rotation from the take-up shaft side from being transmitted to the motor, a clutch is interposed between the output shaft of the motor and the take-up shaft. Only the rotation from the output shaft side is transmitted to the winding shaft.

  However, in such a conventional motor retractor, since it is necessary to dispose the clutch corresponding to the axial end portion of the winding shaft, the clutch device is disposed on the outer side of the pair of leg plates constituting the frame. The motor is disposed outside the leg plate on the side where the clutch is provided (that is, similar to the clutch), or the motor is disposed above or below the frame from the pair of leg plates. However, in the case of such a configuration, a relatively large and heavy component such as a motor is positioned on the outer side of the frame, above or below the frame, so that the entire motor retractor is enlarged and the weight of the entire motor retractor is increased. There was a drawback of poor balance.

Moreover, in this type of motor retractor, the speed ratio (reduction ratio) of the driving force transmitted from the motor to the clutch can be easily changed and set, and the rotational speed transmitted to the clutch when the motor is driven, and thus the winding shaft There is also a demand to easily set and change the rotation speed (setting of webbing take-up characteristics variation).
JP 2001-130376 A JP 2001-347923 A

  In consideration of the above facts, the present invention not only can rotate the winding shaft by a motor, but also has a simple and compact structure, has a good weight balance, and can easily set variations in webbing winding characteristics. It is an object to obtain a webbing take-up device that can be used.

  The webbing take-up device according to the first aspect of the present invention includes a frame in which a pair of leg plates facing each other are connected by a back plate, and the pair of leg plates in an axial direction along the opposing direction of the pair of leg plates. A winding shaft that is rotatably supported between the leg plates of the occupant, the base end portion of the webbing belt for restraining the occupant is locked, and the webbing belt is wound by rotation in one direction around the shaft, and the rotating shaft is the winding A plurality of motors arranged between the pair of leg plates in a state orthogonal to the spindle and the output side facing away from the back plate, and a plurality of shafts arranged in parallel with the rotation shaft of the motor. A motor gear portion composed of a spur gear and a side of either one of the pair of leg plates, mechanically interposed between the motor and the winding shaft, and rotating the motor Rotate the winding shaft by transmitting to the winding shaft And a clutch that prevents transmission of the rotation generated on the winding shaft side and prevents the rotation from being transmitted to the motor, and its own shaft is arranged in a state parallel to the rotation shaft of the motor. A worm gear connected to the final spur gear of the motor gear portion, and a clutch gear portion comprising a worm wheel arranged coaxially with the winding shaft and meshing with the worm gear to transmit the rotational force of the worm gear to the clutch. And a final spur gear of the motor gear part is detachably connected to the worm gear of the clutch gear part so that the motor and the motor gear part can be separated in an assembled state.

  In the webbing take-up device according to claim 1, the occupant sits on the seat of the vehicle, hangs the webbing belt on the body, for example, by engaging a tongue plate provided on the webbing belt with the buckle device. The belt is attached to the occupant body.

  Further, for example, when an obstacle is present in front of the vehicle while the vehicle is traveling and the distance between the vehicle and the obstacle (distance from the vehicle to the obstacle) reaches a predetermined range, the driving of the motor is started. When the motor is driven, the driving force is transmitted to the clutch by the motor gear portion (plural spur gears) and the clutch gear portion (worm gear and worm wheel), and further the rotational force is transmitted to the winding shaft via the clutch. The winding shaft is rotated in the webbing winding direction. As a result, the webbing belt is wound around the take-up shaft from the base end side, and the slight slackness of the webbing belt in the mounted state, so-called “slack”, is eliminated, and the restraining force of the occupant's body by the webbing belt can be increased. it can.

  Here, in the webbing take-up device according to claim 1, the clutch is disposed on the side of one of the pair of leg plates constituting the frame for supporting the take-up shaft, and the rotating shaft is Since the motor is arranged between the pair of leg plates in a state orthogonal to the take-up shaft, the webbing take-up device as a whole is significantly more compact than the structure in which the motor is arranged outside the frame. Can be. That is, since a relatively large component such as a motor is arranged between a pair of leg plates, the motor, which is the large component, does not protrude outward from the leg plate, and the space between the pair of leg plates is reduced. It can be used effectively, and the device can be made compact as a whole. Moreover, since the motor is arranged between the pair of leg plates as described above as compared with the structure in which the motor is arranged outside the frame, the overall weight balance of the webbing take-up device is set in the direction opposite to the leg plates. The webbing retractor can be stabilized in terms of weight.

  Further, since the clutch is arranged on the side of one leg plate and the motor is arranged between the pair of leg plates, the motor and the clutch can be arranged close to each other, and the output side of the rotation shaft of the motor is opposite to the back plate. Therefore, the motor gear portion (plural spur gears) and the clutch gear portion (worm gear and worm wheel) that connect the output shaft of the motor and the clutch can be arranged without difficulty. Thereby, the structure of the reduction mechanism by a motor gear part and a clutch gear part can be simplified, and also in this meaning, an apparatus can be made compact and cost can also be made cheap.

  Furthermore, since it is the structure which has arrange | positioned comparatively heavy parts like a motor between a pair of leg boards, it is not only one of each leg board and the back board which connects these leg boards, but as needed. The motor can be supported by any two or all of the pair of leg plates and the back plate connecting these leg plates. As a result, it is not necessary to improve the strength for supporting the motor, and as a result, it is possible to reduce the weight and cost of the apparatus.

  Furthermore, in the webbing take-up device according to claim 1, the final spur gear of the motor gear portion and the worm gear of the clutch gear portion are detachably connected, and the motor and the motor gear portion can be separated while being assembled. It has become. In other words, the motor and the motor gear portion can be separated and replaced independently of the clutch gear portion. For this reason, for example, it can be easily exchanged and applied to another different motor gear portion in which the number of teeth of a plurality of spur gears, the number thereof, or the like is changed. This makes it possible to easily change and set the transmission gear ratio (reduction ratio) of the driving force transmitted from the motor to the clutch, and to set / change the rotational speed transmitted to the clutch when the motor is driven, and consequently the rotational speed of the winding shaft ( Webbing take-up characteristics variations can be easily set and handled.

  On the other hand, the webbing take-up device according to the second aspect of the present invention includes a frame in which a pair of leg plates facing each other are connected by a back plate, and an axial direction along the opposing direction of the pair of leg plates. A winding shaft that is rotatably supported between the pair of leg plates, the base end portion of the webbing belt for restraining passengers is locked, and the webbing belt is wound up in one direction around the shaft; The motor is disposed between the pair of leg plates in a state orthogonal to the winding shaft and the output side is directed to the opposite side of the back plate, and its own shaft is disposed in parallel with the rotation shaft of the motor. A motor gear portion composed of a plurality of spur gears and a side of either one of the pair of leg plates, mechanically interposed between the motor and the winding shaft, and rotating the motor Is transmitted to the take-up shaft to rotate the take-up shaft. And a clutch that prevents transmission of the rotation generated on the winding shaft side and prevents the rotation from being transmitted to the motor, and its own shaft is arranged in parallel with the rotation shaft of the motor. A worm gear connected to the final spur gear of the motor gear part; a clutch gear part comprising a worm wheel arranged coaxially with the winding shaft and meshing with the worm gear to transmit the rotational force of the worm gear to the clutch; The motor and the motor gear portion are integrally assembled into a single housing to form a unit, and the clutch and the clutch gear portion are integrally assembled to a single case to form a unit. It is characterized by.

  In the webbing take-up device according to claim 2, the occupant sits on the seat of the vehicle, hangs the webbing belt on the body, for example, by engaging a tongue plate provided on the webbing belt with the buckle device. The belt is attached to the occupant body.

  Further, for example, when an obstacle is present in front of the vehicle while the vehicle is traveling and the distance between the vehicle and the obstacle (distance from the vehicle to the obstacle) reaches a predetermined range, the driving of the motor is started. When the motor is driven, the driving force is transmitted to the clutch by the motor gear portion (plural spur gears) and the clutch gear portion (worm gear and worm wheel), and further the rotational force is transmitted to the winding shaft via the clutch. The winding shaft is rotated in the webbing winding direction. As a result, the webbing belt is wound around the take-up shaft from the base end side, and the slight slackness of the webbing belt in the mounted state, so-called “slack” is eliminated, and the restraining force of the occupant's body by the webbing belt can be increased. it can.

  Here, in the webbing take-up device according to claim 2, the clutch is disposed on the side of one of the pair of leg plates constituting the frame for supporting the take-up shaft, and the rotating shaft is Since the motor is arranged between the pair of leg plates in a state orthogonal to the take-up shaft, the webbing take-up device as a whole is significantly more compact than the structure in which the motor is arranged outside the frame. Can be. That is, since a relatively large component such as a motor is arranged between a pair of leg plates, the motor, which is the large component, does not protrude outward from the leg plate, and the space between the pair of leg plates is reduced. It can be used effectively, and the device can be made compact as a whole. Moreover, since the motor is arranged between the pair of leg plates as described above as compared with the structure in which the motor is arranged outside the frame, the overall weight balance of the webbing take-up device is set in the direction opposite to the leg plates. The webbing retractor can be stabilized in terms of weight.

  Further, since the clutch is arranged on the side of one leg plate and the motor is arranged between the pair of leg plates, the motor and the clutch can be arranged close to each other, and the output side of the rotation shaft of the motor is opposite to the back plate. Therefore, the motor gear portion (plural spur gears) and the clutch gear portion (worm gear and worm wheel) that connect the output shaft of the motor and the clutch can be arranged without difficulty. Thereby, the structure of the reduction mechanism by a motor gear part and a clutch gear part can be simplified, and also in this meaning, an apparatus can be made compact and cost can also be made cheap.

  Furthermore, since it is the structure which has arrange | positioned comparatively heavy parts like a motor between a pair of leg boards, it is not only one of each leg board and the back board which connects these leg boards, but as needed. The motor can be supported by any two or all of the pair of leg plates and the back plate connecting these leg plates. As a result, it is not necessary to improve the strength for supporting the motor, and as a result, it is possible to reduce the weight and cost of the apparatus.

  Furthermore, in the webbing take-up device according to claim 2, the motor and the motor gear portion are integrally assembled into a single housing to form a unit, and the clutch and the clutch gear portion are a single case. Is assembled into a unit. For this reason, for example, even when the motor gear part is replaced or changed for changing the transmission gear ratio (reduction ratio) of the driving force transmitted from the motor to the clutch, the engagement of the plurality of spur gears of the motor gear part The state and the meshing state of the worm gear and the worm wheel in the clutch gear part are not changed (not affected). Therefore, the meshing accuracy of each tooth (gear) is not changed, and the transmission efficiency of the driving force is not lowered (deteriorated).

  A webbing take-up device according to a third aspect of the present invention is the webbing take-up device according to the first or second aspect, wherein a housing to which the motor is attached, a motor cover that covers the motor, and the motor A base plate disposed between the motor cover, a first concave portion provided in the motor cover, and a convex portion provided in the base plate corresponding to the first concave portion and capable of being fitted into the first concave portion; A second concave portion provided in the motor corresponding to the convex portion, into which the convex portion can be fitted, a claw portion provided in the motor cover, and a claw provided in the housing corresponding to the claw portion. A claw receiving portion that can be locked by the portion, and the convex portion is fitted into the second concave portion to position the motor with respect to the base plate, and the convex portion is arranged in the first concave portion. And the base plate is positioned on the motor cover, and the claw portion is locked to the claw receiving portion and the motor cover is positioned on the housing. It is characterized by specifying the attachment position.

  In the webbing retractor according to the third aspect, the motor is attached to the housing, and the motor is covered with the motor cover.

  Here, in the webbing take-up device according to the third aspect, the motor is positioned with respect to the base plate by fitting the convex portion of the base plate into the second concave portion of the motor, and the convex portion of the base plate is set to the first portion of the motor cover. The base plate is positioned on the motor cover by being fitted in the recess, and the motor cover is positioned on the housing by locking the claw portion of the motor cover to the claw receiving portion of the housing. The assembly position around the motor axis is specified. Therefore, the complicated assembly position alignment of the plurality of parts is unnecessary, and the assemblability is improved.

  A webbing take-up device according to a fourth aspect of the present invention is the webbing take-up device according to the third aspect, wherein the electric harness for driving the motor is directed toward the back plate opposite to the output side. It is taken out from the part.

  In the webbing take-up device according to claim 4, since the electric harness for driving the motor is taken out from the rear end portion of the motor cover toward the back plate of the frame opposite to the motor output side, the harness take-out portion is the frame. Will be protected by the backboard. Therefore, the harness take-out portion does not unnecessarily interfere with or interfere with other parts or parts, and the harness take-out portion itself is prevented from being damaged or damaged.

  A webbing take-up device according to a fifth aspect of the present invention is the webbing take-up device according to the fourth aspect, wherein the electric harness take-out portion of the motor cover is waterproofed by a rubber cap.

  In the webbing take-up device according to the fifth aspect, since the rubber cap is protected by the back plate of the frame, the waterproofness of the harness take-out portion is further improved.

  A webbing take-up device according to a sixth aspect of the present invention is the webbing take-up device according to any one of the first to fifth aspects, wherein the electric harness for driving the motor is provided in a main body portion of the motor. The power supply terminal is connected by a crimp terminal structure.

  In the webbing take-up device according to claim 6, since the electric harness for driving the motor is connected to the power supply terminal provided in the main body portion of the motor by a crimp terminal structure, for example, compared with a connection structure such as soldering. In addition, the workability of harness connection can be improved and the physique can be reduced (the required space of the part can also be reduced).

  A webbing take-up device according to a seventh aspect of the present invention is the webbing take-up device according to any one of the first to sixth aspects, wherein the motor gear portion is covered with a cover gear, and the cover gear is engaged. It is characterized by being fixed to the housing by a pawl.

  In the webbing take-up device according to the seventh aspect, the structure becomes simple and the assembling workability is improved.

  As described above, the webbing take-up device according to the present invention is not only capable of rotating the take-up shaft by a motor, but also has a simple and compact structure with good weight balance, and setting of variations in webbing take-up characteristics. It has an excellent effect that it can be easily performed.

  FIG. 1 is a perspective view showing the overall configuration of a webbing take-up device 10 according to an embodiment of the present invention, and FIG. 2 is a perspective view showing the configuration of the main part of the webbing take-up device 10. Is shown. FIG. 3 is an exploded perspective view showing the overall configuration of the webbing take-up device 10.

  The webbing take-up device 10 includes a frame 12. The frame 12 includes a substantially plate-like back plate 14 and a pair of leg plates 16 and 18 that extend integrally from both ends of the back plate 14 in the width direction. The back plate 14 is a fastening member (not shown) such as a bolt. It is configured to be attached to the vehicle body by being fixed to the vehicle body by means.

  Between the pair of leg plates 16 and the leg plates 18 of the frame 12, a winding shaft 20 manufactured by die casting or the like is rotatably arranged. The winding shaft 20 has a drum shape as a whole, and a base end portion of a webbing belt (not shown) formed in a long belt shape is connected and fixed. When the winding shaft 20 is rotated to one side around the axis (hereinafter, this direction is referred to as “winding direction”), the webbing belt is wound in layers on the outer periphery of the winding shaft 20 from the base end side, On the other hand, when the webbing belt is pulled from the front end side, the webbing belt is pulled out while the winding shaft 20 rotates (hereinafter, the rotation direction of the winding shaft 20 when the webbing belt is pulled out is referred to as “drawing direction”). Called).

  One end side of the winding shaft 20 passes through the leg plate 18 and protrudes to the outside of the frame 12. A locking mechanism (not shown) is arranged on the side of the leg plate 18. The lock mechanism is configured to include an acceleration sensor, and is linked to a lock plate 22 spanned between the leg plate 16 and the leg plate 18 and a torsion bar 24 provided at the shaft core portion of the take-up shaft 20. ing. When the vehicle is suddenly decelerated or the like, one end of the torsion bar 24 is restrained via the lock plate 22 by the operation of the lock mechanism, and energy absorption is performed, while the take-up shaft 20 is prevented from rotating in the pull-out direction. It has become.

  On the other hand, a connecting screw 21 is attached to the other end side of the winding shaft 20. The connecting screw 21 penetrates the leg plate 16 and protrudes outward from the frame 12, and a clutch 26 and a clutch gear portion 28 are disposed outside the leg plate 16.

  The clutch 26 and the clutch gear portion 28 are both housed in a case 30, and the clutch 26 is connected to the connecting screw 21. The clutch 26 is linked to a gear wheel 32 that constitutes the clutch gear portion 28. The gear wheel 32 is a so-called worm wheel in which worm wheel teeth are formed on the outer peripheral edge. The gear wheel 32 is arranged coaxially with the winding shaft 20, and this gear wheel 32 is mechanically connected to the coupling screw 21 (that is, the winding shaft 20) via the clutch 26. For this reason, when the gear wheel 32 rotates, a driving force is transmitted through the clutch 26, the winding shaft 20 is rotated in the winding direction, and transmission of rotation generated on the winding shaft 20 side is cut off. The rotation is prevented from being transmitted to the gear wheel 32. Further, the tip of the connecting screw 21 connected to the clutch 26 extends laterally through the clutch 26.

  A worm gear 34 that constitutes the clutch gear portion 28 is provided in the case 30. The worm gear 34 has its own shaft disposed in a state orthogonal to the winding shaft 20, and its end is supported by the case 30 via bushes 36 and 37 and meshed with the gear wheel 32, One end side is provided to protrude outward from the case 30. Further, a steel ball 38 is accommodated in the bearing portion of the case 30 that supports the tip portion of the worm gear 34 and is in contact with the tip portion of the worm gear 34, and an adjustment screw 40 is screwed. The adjusting screw 40 presses the steel ball 38 at its tip, thereby pressing the steel ball 38 against the tip of the worm gear 34. Thereby, the axial displacement of the worm gear 34 is regulated (thrust adjustment). The gear wheel 32 is rotated by rotating the worm gear 34.

  The case 30 that houses the clutch 26 and the clutch gear portion 28 configured as described above is covered with a cover clutch 31.

  As described above, the clutch 26 and the clutch gear portion 28 are integrally assembled to the single case 30 and are configured as a unit as a whole.

  A spring complete 42 is disposed on the side of the clutch 26 and the clutch gear portion 28 (case 30). The spring complete 42 accommodates a spiral spring (not shown) inside. In the spiral spring, the end on the outer side in the spiral direction is locked to the case body, and the end on the inner side in the spiral direction is locked to the tip of the connecting screw 21 that penetrates the clutch 26. Is energized in the winding direction.

  On the other hand, a motor 44 and a motor gear portion 46 are disposed below the winding shaft 20 and between the leg plate 16 and the leg plate 18.

  Here, in FIG. 4, the configurations of the motor 44 and the motor gear portion 46 are shown in an exploded perspective view.

  The motor 44 and the motor gear portion 46 include a housing 48. A motor 44 is attached to one side of the housing 48, and a motor gear portion 46 is provided on the other side of the housing 48. The motor 44 is fixed to one side of the housing 48 with the distal end side (output side) of the rotary shaft 50 facing the housing 48, and the distal end (output side) of the rotary shaft 50 is fixed to the other side of the housing 48 (motor gear portion). 46 side).

  A base plate 54 is attached to the rear end side of the motor 44. An electric harness 52 for driving the motor is routed around the base plate 54. Further, as shown in FIG. 5, the electric harness 52 is connected to a power supply terminal 56 provided in the main body portion of the motor 44 by a crimp terminal structure. It is connected.

  Further, the motor 44 is covered with a cover motor 58 with an O-ring 57 interposed. The cover motor 58 is provided with a claw portion 60, and the claw portion 60 is fitted and locked to a claw receiving projection 62 provided on the housing 48, whereby the cover motor 58 is fixed to the housing 48.

  Here, the cover motor 58 is provided with a first concave portion 64, and the base plate 54 is provided with a convex portion 66 that can be fitted into the first concave portion 64 corresponding to the first concave portion 64. Further, the motor 44 is provided with a second recess 68 into which the projection 66 can be fitted in correspondence with the projection 66 of the base plate 54.

  That is, the convex portion 66 is fitted into the second concave portion 68 to position the motor 44 with respect to the base plate 54, the convex portion 66 is fitted into the first concave portion 64, the base plate 54 is positioned to the cover motor 58, and the claw portion The assembly position of the motor 44 around the shaft with respect to the housing 48 is uniquely specified by fitting and locking 60 to the claw receiving projection 62 and fixing the cover motor 58 to the housing 48. .

  Further, the electric harness 52 for driving the motor is taken out from the rear end portion of the cover motor 58 toward the back plate 14 of the frame 12 opposite to the output side of the motor 44. Further, the take-out portion of the electric harness 52 of the cover motor 58 is waterproofed by a rubber cap 70.

  On the other hand, pinions 72 constituting a plurality of spur gears of the motor gear portion 46 are attached to the distal end of the rotating shaft 50 of the motor 44 projecting to the other side of the housing 48 (motor gear portion 46 side). Further, the motor gear portion 46 accommodates a gear 74 and a gear 76 that constitute driving force transmitting means, each of which is an external spur gear, in mesh with each other. Both the gear 74 and the gear 76 are arranged with their own axes parallel to the rotating shaft 50 of the motor 44, the gear 74 meshes with the pinion 72, and the gear 76 that is the final spur gear is The clutch gear portion 28 is detachably connected to one end portion of the worm gear 34 protruding outward from the case 30 of the clutch gear portion 28. Therefore, when the motor 44 is driven, the driving force is transmitted via the pinion 72, the gear 74, and the gear 76, and the worm gear 34 is rotated.

  The pinion 72, the gear 74, and the gear 76 are covered with a cover gear 78 attached to the housing 48. The cover gear 78 is provided with a claw portion 80, and the cover gear 78 is fixed to the housing 48 by fitting and locking the claw portion 80 to a claw receiving portion 82 provided on the housing 48.

  Thus, both the motor 44 and the motor gear portion 46 are integrally assembled in a single housing 48 and are configured as a unit as a whole.

  In the motor 44 and the motor gear portion 46 configured as described above, the mounting stay 84 provided integrally with the housing 48 can be attached to and detached from the case 30 (that is, the frame 12) housing the clutch 26 and the clutch gear portion 28 by the screw 86. It is attached. In a state where the housing 48 is attached to the case 30 (frame 12), the motor 44 is in a state in which the rotating shaft 50 is orthogonal to the winding shaft 20 and the output side thereof faces away from the back plate 14 of the frame 12. In addition, it is configured between the pair of leg plates 16 and the leg plates 18 and directly below the take-up shaft 20.

  Further, here, the motor 44 and the motor gear portion 46 configured as described above are separably coupled to the worm gear 34 of the clutch 26 and the clutch gear portion 28 with a gear 76 as a final spur gear of the motor gear portion 46. In addition, since the mounting stay 84 is detachably attached to the case 30 by the screw 86, the case where the motor 44 and the motor gear portion 46 remain in the assembled state by removing the screw 86 and removing the mounting stay 84 from the case 30. 30 (frame 12) can be separated independently.

  Furthermore, the motor 44 described above is configured to be operated based on a detection signal from a forward monitoring device, for example.

  Next, the operation of this embodiment will be described.

  In the webbing take-up device 10 configured as described above, an occupant sits on a vehicle seat, hangs the webbing belt around the body, and, for example, engages a tongue plate provided on the webbing belt with the buckle device. It will be in the wearing state for the passenger body.

  Here, even when the webbing belt is wound and pulled out due to the movement of the occupant in the state where the webbing belt is worn, that is, even if the winding shaft 20 rotates in the winding direction or the pulling direction, the clutch 26, the rotational force of the winding shaft 20 is not transmitted to the rotational shaft 50 of the motor 44.

  On the other hand, for example, when an obstacle is present in front of the vehicle while the vehicle is running and the distance between the vehicle and the obstacle (the distance from the vehicle to the obstacle) reaches a predetermined range, the driving of the motor 44 is started, The rotating shaft 50 is rapidly rotated.

  When the rotating shaft 50 of the motor 44 is rotated, the rotational force is transmitted to the clutch 26 by the pinion 72, the gear 74, and the gear 76 of the motor gear portion 46, and the worm gear 34 and the gear wheel 32 of the clutch gear portion 28. Further, a rotational force is transmitted to the take-up shaft 20 via the clutch 26, and the take-up shaft 20 is rotated in the webbing take-up direction. As a result, loosening of the webbing belt, so-called “slack”, is eliminated, and the restraining force of the webbing belt on the occupant's body is improved. Even when the vehicle is decelerated, the webbing belt reliably holds the occupant's body.

  Further, when the motor 44 is stopped in such a state that the slack is eliminated, the mechanical connection between the rotating shaft 50 and the winding shaft 20 of the motor 44 is released.

  Here, in the webbing take-up device 10 according to the present embodiment, the clutch 26 is disposed on the side of one leg plate 16 of the pair of leg plates 16 and 18 constituting the frame 12 for supporting the take-up shaft 20. In addition, since the motor 44 is disposed between the leg plate 16 and the leg plate 18 in a state where the rotation shaft 50 is orthogonal to the winding shaft 20 and directly below the winding shaft 20, the frame 12 Compared with the structure in which the motor 44 is arranged outside, the webbing take-up device 10 can be made significantly compact as a whole. That is, since a relatively large component such as the motor 44 is arranged between the pair of leg plates 16 and the leg plate 18 and directly below the take-up shaft 20, the motor 44, which is the large component, is attached to the frame. Thus, the space between the pair of leg plates 16 and the leg plate 18 can be used effectively, and the device can be made compact as a whole. Moreover, since the motor 44 is disposed between the pair of leg plates 16 and 18 and directly below the winding shaft 20 as compared with the structure in which the motor 44 is disposed outside the frame 12, The overall weight balance of the webbing take-up device 10 can be brought closer to the center side in the opposing direction of the leg plate 16 and the leg plate 18, and the webbing take-up device 10 can be stabilized in terms of weight.

  Further, in the webbing take-up device 10 according to the present embodiment, the clutch 26 is disposed on the side of one leg plate 16 and the motor 44 is disposed between the pair of leg plates 16 and 18 and directly below the take-up shaft 20. Since the arrangement is such that the motor 44 and the clutch 26 can be arranged close to each other, and the output side of the rotating shaft 50 of the motor 44 is arranged facing away from the back plate 14 of the frame 12, the motor 44 The motor gear portion 46 and the clutch gear portion 28 (driving force transmission means) that connect the rotary shaft 50 and the clutch 26 can be arranged without difficulty. Therefore, the configuration of the motor gear portion 46 and the clutch gear portion 28 can be simplified. In this sense, the apparatus can be made compact and the cost can be reduced.

  Further, since a relatively heavy component such as the motor 44 is disposed between the pair of leg plates 16 and 18 and directly below the take-up shaft 20, each leg plate 16, 18 and the leg plates 16, The motor 44 can be supported by any two or all of the pair of leg plates 16, 18 and the back plate 14 as needed, as well as any one of the back plates 14 connecting the 18. As a result, it is not necessary to improve the strength for supporting the motor 44. As a result, it is possible to reduce the weight and cost of the apparatus.

  Furthermore, in the webbing take-up device 10 according to the present embodiment, the gear 76 as the final spur gear of the motor gear portion 46 and the worm gear 34 of the clutch gear portion 28 are detachably connected, so that the motor gear portion 46 can be separated and replaced independently of the clutch gear portion 28. Therefore, for example, it can be easily replaced / applied to another different motor gear portion 46 in which the number of teeth or the number of spur gears such as the pinion 72, the gear 74, and the gear 76 are changed. As a result, the speed ratio (reduction ratio) of the driving force transmitted from the motor 44 to the clutch 26 can be easily changed and set. The rotational speed transmitted to the clutch 26 when the motor 44 is driven, and thus the rotational speed of the take-up shaft 20. Can be easily set / changed (variation of webbing take-up characteristics).

  Further, the motor 44 and the motor gear portion 46 are integrally assembled into a single housing 48 to form a unit, and the clutch 26 and the clutch gear portion 28 are integrally assembled into a single case 30. Are unitized. For this reason, even when the motor gear portion 46 is replaced or changed for changing the transmission gear ratio (reduction ratio) as described above, the meshing state of the plurality of spur gears of the motor gear portion 46 and the clutch gear are changed. The meshing state of the worm gear 34 and the gear wheel 32 of the portion 28 does not change at all (not affected). Therefore, the meshing accuracy of each tooth (gear) is not changed, and the transmission efficiency of the driving force is not lowered (deteriorated).

  Further, in the webbing retractor 10 according to the present embodiment, the motor 44 is positioned with respect to the base plate 54 by fitting the convex portion 66 of the base plate 54 into the second concave portion 68 of the motor 44, and the base plate 54. The base plate 54 is positioned on the cover motor 58 by fitting the convex portion 66 of the cover motor 58 into the first concave portion 64 of the cover motor 58, and the claw portion 60 of the cover motor 58 is engaged with the claw receiving projection 62 of the housing 48. By stopping, the cover motor 58 is attached to the housing 48, and the assembly position around the axis of the motor 44 with respect to the housing 48 is specified. Accordingly, complicated assembly position alignment of the plurality of parts is not necessary (simply fitting the second concave portion 68, the convex portion 66, and the first concave portion 64 and fitting the claw portion 60 to the claw receiving projection 62). Assembling is improved.

  Similarly, in the webbing take-up device 10 according to the present embodiment, the motor gear portion 46 is covered with a cover gear 78, and the cover gear 78 is housed by fitting and locking the claw portion 80 to the claw receiving portion 82. Since it is fixed to 48, the structure becomes simple and the assembly workability is improved.

  Further, in the webbing take-up device 10 according to the present embodiment, since the electric harness 52 is connected to the power supply terminal 56 provided in the main body portion of the motor 44 by a crimp terminal structure, for example, a connection structure such as soldering Compared to the above, the workability of harness connection can be improved and the physique can be reduced (the required space of the part can also be reduced).

  Furthermore, in the webbing retractor 10 according to the present embodiment, the electric harness 52 for driving the motor is directed from the rear end portion of the cover motor 58 toward the back plate 14 of the frame 12 opposite to the output side of the motor 44. Since it is taken out, the harness take-out portion is protected by the back plate 14 of the frame 12. Therefore, the harness take-out portion does not unnecessarily interfere with or interfere with other parts or parts, and the harness take-out portion itself is prevented from being damaged or damaged.

  Moreover, the take-out portion of the electrical harness 52 is waterproofed by the rubber cap 70. However, since the rubber cap 70 is also protected by the back plate 14 of the frame 12, the waterproofness of the harness take-out portion is further improved. To do.

1 is a perspective view showing an overall configuration of a webbing take-up device according to an embodiment of the present invention. It is a perspective view which shows the structure of the principal part of the webbing winding device concerning an embodiment of the invention. It is a disassembled perspective view which shows the whole structure of the webbing winding device concerning an embodiment of the invention. It is a disassembled perspective view which shows the structure structure of the motor and motor gear part of the webbing retractor which concerns on embodiment of this invention. It is a perspective view which shows the crimp terminal structure of the electric power feeding terminal and electric harness of the motor of the webbing retractor which concerns on embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Webbing winding device 12 Frame 14 Back plate 16 Leg plate 18 Leg plate 20 Winding shaft 26 Clutch 28 Clutch gear part 30 Case 32 Gear wheel 34 Worm gear 44 Motor 46 Motor gear part 48 Housing 72 Pinion 74 Gear 76 Gear

Claims (7)

A frame in which a pair of leg plates facing each other are connected by a back plate, and
Rotation is supported between the pair of leg plates in a state where the axial direction is along the opposing direction of the pair of leg plates, and the base end portion of the webbing belt for restraining the passenger is locked to rotate in one direction around the axis. A winding shaft for winding the webbing belt with,
A motor disposed between the pair of leg plates in a state where the rotation shaft is orthogonal to the winding shaft and the output side faces the opposite side of the back plate;
A motor gear portion composed of a plurality of spur gears each having its own shaft arranged parallel to the rotation shaft of the motor;
It is disposed on the side of one of the pair of leg plates, and is mechanically interposed between the motor and the take-up shaft, and transmits the rotation of the motor to the take-up shaft to make the winding. A clutch that rotates the take-up shaft, interrupts transmission of rotation generated on the take-up shaft side, and prevents the rotation from being transmitted to the motor;
A worm gear having its own shaft arranged in parallel with the rotation axis of the motor and connected to the final spur gear of the motor gear portion, and being arranged coaxially with the winding shaft and meshing with the worm gear, the rotational force of the worm gear A clutch gear part comprising a worm wheel for transmitting the clutch to the clutch;
With
The final spur gear of the motor gear portion is detachably connected to the worm gear of the clutch gear portion, and the motor and the motor gear portion can be separated while being assembled.
A webbing take-up device characterized by that. A frame in which a pair of leg plates facing each other are connected by a back plate, and
Rotation is supported between the pair of leg plates in a state where the axial direction is along the opposing direction of the pair of leg plates, and the base end portion of the webbing belt for restraining the passenger is locked to rotate in one direction around the axis. A winding shaft for winding the webbing belt with,
A motor disposed between the pair of leg plates in a state where the rotation shaft is orthogonal to the winding shaft and the output side faces the opposite side of the back plate;
A motor gear portion composed of a plurality of spur gears each having its own shaft arranged parallel to the rotation shaft of the motor;
It is disposed on the side of one of the pair of leg plates, and is mechanically interposed between the motor and the take-up shaft, and transmits the rotation of the motor to the take-up shaft to make the winding. A clutch that rotates the take-up shaft, interrupts transmission of rotation generated on the take-up shaft side, and prevents the rotation from being transmitted to the motor;
A worm gear having its own shaft arranged in parallel with the rotation axis of the motor and connected to the final spur gear of the motor gear portion, and being arranged coaxially with the winding shaft and meshing with the worm gear, the rotational force of the worm gear A clutch gear part comprising a worm wheel for transmitting the clutch to the clutch;
With
The motor and the motor gear portion are integrally assembled into a single housing to form a unit, and the clutch and the clutch gear portion are integrally assembled to a single case to form a unit.
A webbing take-up device characterized by that. A housing to which the motor is attached; a motor cover that covers the motor; a base plate disposed between the motor and the motor cover; a first recess provided in the motor cover; and a first recess Correspondingly provided on the base plate and can be fitted into the first recess, provided on the motor corresponding to the raised portion and provided on the motor cover, and on the motor cover. And a claw receiving portion provided in the housing corresponding to the claw portion and capable of locking the claw portion.
The convex portion is fitted into the second concave portion to position the motor with respect to the base plate, the convex portion is fitted into the first concave portion to position the base plate on the motor cover, and the claw portion is The assembly position around the shaft of the motor relative to the housing was specified by locking the claw receiving portion and positioning the motor cover on the housing.
The webbing take-up device according to claim 1 or 2, characterized in that The electric harness for driving the motor was taken out from the rear end portion of the motor cover toward the back plate opposite to the output side,
The webbing take-up device according to claim 3.   The webbing take-up device according to claim 4, wherein the electric harness take-out portion of the motor cover is waterproofed with a rubber cap.   The webbing winding according to any one of claims 1 to 5, wherein the electric harness for driving the motor is connected to a power supply terminal provided in a main body portion of the motor by a crimping terminal structure. Taking device.   The webbing retractor according to any one of claims 1 to 6, wherein the motor gear portion is covered with a cover gear, and the cover gear is fixed to the housing by a locking claw. .

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