WO2009060667A1

WO2009060667A1 - Seatbelt retractor and seatbelt device with the same

Info

Publication number: WO2009060667A1
Application number: PCT/JP2008/066896
Authority: WO
Inventors: Ro Ohashi; Tomofumi Nakagawa; Kenji Ikeda
Original assignee: Takata Corporation
Priority date: 2007-11-08
Filing date: 2008-09-11
Publication date: 2009-05-14
Also published as: JP2009113718A; JP5191213B2

Abstract

A seatbelt retractor has a magnet holding member (20) for holding a large number of annularly arranged magnets (19) and transmitting rotation of a spool to each magnet (19). The magnet holding member (20) has an inner peripheral section (20a), an outer peripheral section (20b), and a predetermined number of connection sections (20c) for interconnecting the inner peripheral and outer peripheral sections and arranged at predetermined intervals in the circumferential direction. The connection sections (20c) each have a radial connection section (20c1) extended in the radial direction, a circumferential connection section (20c2) extended in the substantially circumferential direction, and a bent section (20c3) located between the radial and circumferential connection sections. The magnet holding member (20) is in-molded or insert-molded with resin integrally with the large number of magnets (19).

Description

Specification

Seat belt retractor and seat belt device provided with the same

The present invention relates to a technical field of a seatbelt retractor configured as a motor retractor that performs belt winding and belt withdrawal by controlling the rotation of a spool in an electric motor and a seatbelt device including the same. To do. In particular, the present invention relates to a technical field of a seat belt retractor having a rotation amount detecting means for detecting a rotation amount of a spool and a seat belt device using the same.

[0002] Seatbelt devices that have conventionally been installed in vehicles such as moving vehicles prevent occupants from jumping out of their seats by restraining the occupant with a seatbelt in an emergency such as a vehicle collision. . Such a seat belt apparatus includes a seat belt retractor that winds up the seat belt. In this seat belt retractor, when the seat belt is not worn, the seat belt is scraped off by the spool, but when the seat belt is worn, it is pulled out and attached to the passenger. Then, in the case of an emergency as described above, the locking means of the belt retractor is actuated to prevent the spool from rotating in the belt withdrawing direction, thereby preventing the seat belt from being withdrawn. As a result, the seat belt restrains the passenger in an emergency.

[0003] In the conventional seat belt device, various belt tension modes are set according to the traveling state of the vehicle and the usage state of the seat belt device, and the spool that winds up the seat belt as a seat belt retractor Japanese Patent Laid-Open No. 2 0 0 5-2 7 1 9 1 7 proposes a seat belt device provided with a motor retractor that rotates a motor with the power of a motor. The seat belt retractor disclosed in Japanese Patent Publication No. 2 0 0 5— 2 7 1 9 1 7 is a belt tension mode belt tension set in accordance with the traveling state of the vehicle and the usage state of the seat belt device. Thus, the controller drives and controls the electric motor, which is the driving means, to control the spool take-up and the belt pull-out of the spool. [0004] By the way, in order for the controller to control the driving of the electric motor to control the winding of the spool and the pulling out of the bell rod, it is necessary to detect the amount and direction of rotation of the spool. Therefore, as a rotation sensor that detects the amount and direction of rotation of the spool, it rotates by detecting a rotating disk, a magnet, and this magnet that are supported on the rotating shaft of the spool so as to rotate together with the spool. A seat belt retractor that includes a rotation sensor that includes a hall element (hole IC) that detects the rotation of the disk and that controls the electric motor based on the amount of rotation of the spool detected by the rotation sensor. This is proposed in Japanese Laid-Open Publication No. 2 0 0 5 — 2 9 7 7 8 1.

[0005] In the rotation sensor described in Japanese Patent Laid-Open No. 2 0 0 5-2 9 7 7 8 1, the rotating disk holds a large number of magnets arranged in an annular shape, and rotates the spool. Each magnet 1 is rotated together with the spool.

[0006] Therefore, in order to detect the rotation of the spool more accurately, the rotating disk is required to rotate as accurately as possible with respect to the rotation of the spool. The rotating disk is required to hold each magnet as stably as possible while suppressing the force applied to each magnet as much as possible by holding each magnet. Disclosure of the invention

An object of the present invention is to provide a sheet capable of stably holding a large number of magnets while suppressing the force applied to each magnet while rotating the rotating disk more accurately with respect to the rotation of the spool. The present invention is to provide a belt retractor and a seat belt device using the belt retractor.

In order to achieve the above object, a seat belt retractor according to the present invention includes a spool for winding a seat belt, a driving means for rotating the spool, and a rotation amount detecting means for detecting the rotation amount of the spool. And based on the rotation amount of the spool detected by the rotation amount detection means In the seat belt retractor, the amount of rotation by the spool is controlled by drivingly controlling the driving unit. In the seat belt retractor, the rotation amount detecting unit is a rotating disk provided so as to be integrally rotatable with the spool, and an N pole magnet A rotating disk having a predetermined number of magnets alternately arranged with S-pole magnets and arranged in an annular shape concentric with the rotating disk, and a magnet holding member for holding the predetermined number of magnets; Magnetic detecting means for detecting a magnet located at a predetermined position among the predetermined number of magnets is provided, and the magnet holding member is formed of resin.

[0009] Further, in the seat belt retractor of the present invention, the magnet holding member is an inner peripheral side portion located on the inner peripheral side of the annular magnet, and an outer periphery located on the outer peripheral side of the annular magnet. And a connecting portion that connects the inner peripheral side portion and the outer peripheral side portion. The magnet holding member includes the inner peripheral side portion, the outer peripheral side portion, and the connecting portion. It is characterized in that it is formed by integral molding or insert molding.

[0010] Further, in the seat belt retractor of the present invention, a radially unconnected portion in which a part of the connecting portion does not exist in the radial direction between the inner peripheral side portion and the outer peripheral side portion is set. It is characterized by.

[0011] Further, in the seat belt retractor of the present invention, the connecting portion is connected to the inner peripheral side connecting portion that is connected to the inner peripheral side portion, and is connected to intersect with the inner peripheral side connecting portion. And an outer peripheral side connecting portion connected to the inner peripheral side, and a bent portion between the inner peripheral side connecting portion and the outer peripheral side portion.

Furthermore, the seat belt retractor of the present invention is characterized in that the magnet holding member has a predetermined number of radial ribs arranged at predetermined intervals in the circumferential direction on the inner peripheral side portion. Yes.

[0013] Further, the seat belt retractor of the present invention includes a seat belt retractor that winds up the seat belt, a tanda that is slidably supported by the seat belt pulled out from the seat belt retractor, and the tanda is engaged and disengaged. And at least a buckle that can be engaged with the occupant by the seat belt. In the seat belt apparatus for restraining the seat belt, the seat belt retractor is any one of the seat belt retractors of the present invention described above.

According to the seat belt retractor of the present invention configured as described above, a magnet holding member that holds a predetermined number of magnets arranged in an annular shape and transmits the rotation of the spool to these magnets. Is made of lightweight resin, the moment of inertia of the magnet holding member can be reduced, and the rotation of the spool can be detected more accurately.

In particular, according to the seat belt retractor of the present invention, the inner peripheral side portion, the outer peripheral side portion, and the inner peripheral side portion and the outer peripheral side portion of the magnet holding member that clamps the annular magnet in the radial direction are connected. Since the connecting part to be formed is integrally formed by resin in-mold molding or insert molding to the annular magnet, each magnet arranged in an annular shape is stably held with a simple structure, The rotation of the spool can be transmitted efficiently. In that case, by setting a radial non-connecting portion in which a part of the connecting portion does not exist in the radial direction between the inner peripheral side portion and the outer peripheral side portion, a force directed directly in the radial direction when the resin contracts is reduced. Can be prevented. Therefore, the stress generated in each magnet due to the contraction force of the connecting portion can be further reduced.

[0016] Further, in the seat belt retractor of the present invention, the connecting portion that connects the inner peripheral side portion and the outer peripheral side portion of the magnet holding member that clamps the annular magnet in the radial direction, and the inner peripheral side connecting portion. Since the bent portion is formed by the outer peripheral side connecting portion intersecting the inner peripheral side connecting portion, when the magnet holding member is contracted, the contraction of the connecting portion is contracted with the contracting direction of the inner peripheral side connecting portion, and the outer peripheral side. It can be set in two different directions from the contraction direction of the connecting part. In this way, by contracting the connecting portion in two different directions, the contraction force of the connecting portion can be dispersed in other directions besides one direction. Thereby, the stress which arises in each magnet by the contraction force of a connection part can be made smaller.

[0017] In that case, of the two directions of contraction, by setting the contraction in one direction to the contraction in the circumferential direction, the cross-sectional area along the circumferential direction of the annular magnet is relatively large Therefore, the stress of the magnet due to the contraction force dispersed in the circumferential direction can be effectively reduced.

[0018] In addition, the bent portion of the connecting portion formed by the intersection of the inner peripheral side connecting portion and the outer peripheral side connecting portion opens the outer peripheral side connecting portion in the direction of the inner peripheral side connecting portion when the magnet holding member contracts. In this way, the connecting part can make a fist that tries to deform. Then, the behavior of the bent portion that deforms acts as a cushion, so that the force caused by the contraction of the connecting portion can be reduced. Therefore, the force applied to each magnet due to the contraction of the connecting portion can be suppressed to be smaller than that when the connecting portion is extended only in the radial direction. Thus, the stress generated in the magnet can be reduced by the cushioning action of the bent portion.

Furthermore, according to the seat belt retractor of the present invention, when the magnet holding member is contracted, the contraction of the inner peripheral side portion can be suppressed by the predetermined number of radial ribs. As a result, the entire shrinkage of the magnet holding member is also suppressed, so that the overall contracting force of the magnet holding member applied to each magnet can also be suppressed. Therefore, the stress generated in each magnet due to the overall contraction force of the magnet holding member can be reduced.

[0020] As described above, even if the magnet holding member is made of resin, the stress generated in each magnet can be reduced, so that it is not necessary to increase the thickness of each magnet. This makes it possible to reduce the thickness of the rotation sensor (the axial length of the spool) while holding each magnet stably. Moreover, since it is not necessary to add a reinforcing material such as a filler to the resin of the magnet holding member in order to cope with the generated stress, it is possible to prevent the physical properties of the resin from being changed by the added material.

[0021] Further, since the thickness of the rotation sensor can be reduced, the seat belt retractor can be formed more effectively and compactly. Therefore, it is possible to sufficiently and faithfully meet the demand for a wider cabin while reducing the overall outer shape of the vehicle required in recent years.

[0022] On the other hand, according to the seat belt device of the present invention, the seat belt belt of the present invention. Since the lacquer is used, the occupant can be restrained efficiently with a seat belt over a long period of time, depending on the vehicle running situation and the use situation of the seat belt device. Brief Description of Drawings

FIG. 1 is a view schematically and partially showing an example of an embodiment of a seat belt retractor according to the present invention.

FIG. 2 (a) is a front view of the rotation sensor of the example shown in FIG.

Figure 2 (b) is a back view of this rotation sensor.

Fig. 2 (c) is a cross-sectional view taken along the line IIC-IIC in Fig. 2 (b). FIG. 3 (a) is a plan view showing the magnet of the rotation sensor of the example shown in FIG.

Fig. 3 (b) is an enlarged view of part IIIB in Fig. 3 (a) showing the relationship between each magnet and the Hall element.

Fig. 3 (c) is a cross-sectional view taken along line IIIC-IIIC in Fig. 3 (b). FIG. 4 is a diagram showing an electrical connection between the Hall element and the controller in the example shown in FIG.

FIG. 5 is a diagram for explaining a magnet detection signal by the Hall element of the example shown in FIG.

FIG. 6 (a) shows a rotation sensor according to another example of the embodiment of the present invention, and is a rear view similar to FIG. 2 (b).

Fig. 6 (b) is a cross-sectional view taken along line VIB-VIB in Fig. 6 (a). FIG. 6 (c) is a rear view similar to FIG. 2 (b), showing a rotation sensor in still another example of the embodiment of the present invention.

Fig. 6 (d) is a cross-sectional view taken along the line VID-VDI in Fig. 6 (c). FIG. 7 (a) is a rear view showing a rotation sensor in still another example of the embodiment of the invention.

FIG. 7 (b) is a back view showing a rotation sensor in still another example of the embodiment of the invention. FIG. 7 (c) is a back view showing a rotation sensor in still another example of the embodiment of the invention.

FIG. 7 (d) is a rear view showing a rotation sensor in still another example of the embodiment of the invention.

FIG. 8 (a) is a back view showing a rotation sensor in still another example of the embodiment of the invention.

FIG. 8 (b) is a rear view showing a rotation sensor in still another example of the embodiment of the invention.

FIG. 8 (c) is a back view showing a rotation sensor in still another example of the embodiment of the invention.

FIG. 8 (d) is a rear view showing a rotation sensor in still another example of the embodiment of the invention.

FIG. 9 is a view showing an example of a seat belt apparatus to which the seat belt retractor of the example shown in FIG. 1 is applied. BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, the best mode for carrying out the present invention will be described with reference to the drawings.

FIG. 1 is a diagram schematically and partially showing an example of an embodiment of a seatbelt retractor according to the present invention.

As shown in FIG. 1, a seat belt retractor 1 of this example is configured as a motor retractor used in a seat belt device, and has a U-shaped frame 2 having left and right side walls 2 a and 2 b. Seat belt 3, spool 2 supported by itself to rotate and spool 4 to wind up seat belt 3, left wall 2 of frame 2 lock mechanism 5 and deceleration sensing mechanism 6 provided on a 2 right side wall 2 of frame 2 Spring mechanism 7 which is a spool 卷 mounting urging mechanism provided in b, an electric motor 8 which is a drive means, a power transmission mechanism 9, and a rotation sensor 10 which is a rotation amount detection means, a controller (CPU) 1 1, And a pretensioner 1 1 2 respectively. [0026] The lock mechanism 5, the deceleration sensing mechanism 6, the spring mechanism 7, and the pretensioner 12 are the same as those of a conventionally known emergency lock type seat belt retractor. That is, the spool 4 is always urged in the belt winding direction by the urging force of the spring mechanism 7, and when the belt is not attached, the entire amount that the seat belt 3 can be wound by the urging force of the spring mechanism 7 is scanned. Rolled up in pool 4. If a greater deceleration than normal is applied to the vehicle while the occupant is wearing the belt, the pretensioner 1 2 will operate and the spool 4 will rotate in the belt winding direction. Then, the spool 4 winds a certain amount of the seat belt 3 to increase the restraining force of the occupant. When the deceleration detection mechanism 6 senses this large deceleration and activates the lock mechanism 5 due to this large deceleration of the vehicle, the lock mechanism 5 is clogged with the rotation of the spool 4 in the pulling out direction of the bell rod. This prevents the seat belt 3 from being pulled out due to the inertia of the occupant, and the occupant is restrained by the seat belt 3 with a predetermined restraining force. The specific configuration and specific operation of the lock mechanism 5, the deceleration sensing mechanism 6, and the spring mechanism 7, which are the basic configurations of the seat belt retractor, are disclosed in, for example, Japanese Patent Laid-Open No. Hei 2 0 0 1-1 8 0 4 As described in Japanese Patent No. 37 and Japanese Laid-Open Patent Publication No. 2 0 0 1-2 2 5 7 19, etc., they are well known in the art and are not characteristic features of the present invention. To do.

On the other hand, the rotation sensor 10 detects the rotation amount of the spool 4 and inputs the rotation amount detection signal to the controller (C PU) 11. Then, the controller (C PU) 11 controls the rotation drive of the electric motor 8 based on the input rotation amount detection signal. Thus, the rotation of the electric motor 8 is decelerated by the power transmission mechanism 9 and transmitted to the spool 4, and the spool 4 is driven to rotate. In that case, a conventionally known power transmission mechanism such as a planetary gear reduction mechanism or an external gear reduction mechanism can be used as the power transmission mechanism 9.

[0028] Then, the controller (CPU) 11 has a belt tension in which the belt tension due to the belt scraping of the spool 4 is variously set in the seat belt device like the seat belt device described in Patent Document 1 described above. Of the modes, the vehicle running status, vehicle specifications, and seat belt device usage status Based on the rotation amount detection signal from the rotation sensor 10, the rotation direction of the motorized motor 8 (belt winding direction or belt pull-out direction) and rotation so that the belt tension is set according to at least one belt tension mode. Control the amount.

As shown in FIG. 1, the rotation sensor 10 of this example includes a rotating disk 14 supported on a rotating shaft 4 a of a spool 4 via a push 13 so as to be rotatable together with the spool 4, and a frame 2. And a Hall element (Hall IC) 16 as a magnetic detection means supported by a bracket 15 on the right side wall 2b. The rotating disk 14 and the hall element 16 are disposed between the spring mechanism 7 and the power transmission mechanism 9 and are covered with a case 17 of the spring mechanism 7 and a case 18 of the power transmission mechanism 9. Thus, by covering the rotation sensor 10 with these cases 17 and 18, the influence of the rotation sensor 10 due to an external noise signal is prevented. A pair of Hall elements 16 are provided at predetermined intervals in the circumferential direction of a circle centered on the rotation shaft 4 a of the spool 4. These Hall elements 16 are electrically connected to the controller 9. The Hall element 16 can also be provided in the case 18.

FIG. 2 shows a rotation sensor of this example, (a) is a front view, (b) is a back view, and (c) is a sectional view taken along line IIC-IIC in (b).

As shown in FIGS. 2 (a) and 2 (b), the rotating disk 14 includes an annular magnet 19 and a circle that holds the magnet 19 and is attached to the rotating shaft 4a of the spool 4 so as to rotate together with the spool 4. And an annular magnet holding member 20. The magnet 19 and the magnet holding member 20 are provided concentrically with each other.

[0031] As shown in Fig. 3 (a), the annular magnet 19 is composed of a number of N pole magnets 19 N and a number of S pole magnets 19 S, and both of the magnets 19N, 19 S It is formed with a circumferential width of a predetermined angle in the circumferential direction (7.5 ° in the illustrated example, but not limited to this; it will be described as 7.5 ° in this description below). And each N pole and S pole magne 1 9 N and 1 9 S are alternately arranged without gaps. Therefore, the magnets 1 9 N and 19 S are arranged at a predetermined interval equal to the circumferential width.

[0032] As shown in Figs. 2 (a) to (c), the magnet holding member 20 is partially formed on one side of each N pole and S pole magnet 19 N, 19 S arranged in an annular shape. The N pole and S pole magnets 19 N and 19 S are formed so as to cover the outer peripheral surface and the inner peripheral surface. That is, the magnet holding member 20 is composed of an inner peripheral side portion 20 a located in the inner peripheral region of each N-pole and S-pole magnet 19 N, 19 S, and each N-pole and S-pole magnet 19 N , 19 S An annular outer peripheral side 20 b located on the outer peripheral surface of the S, and a predetermined number connecting the inner peripheral side 20 a and the outer peripheral side 20 b (six in the example shown; The connection part 20 c is not limited to the above.

[0033] A through hole 20 ai is formed at the center of the inner peripheral side portion 20 a, and a predetermined number (2) of two opposing portions on the inner peripheral surface of the through hole 20 ai In the illustrated example, four spline teeth 20 a ₂ are formed (but not limited to this). Then, the rotation shaft 4 a of the spool 4 passes through the through hole 20 _ai , and each spline tooth 20 a ₂ is engaged with a spline groove (not shown) formed on the rotation shaft 4 a of the spool 4. The inner peripheral side portion 20 a is rotationally connected to the rotating shaft 4 a.

[0034] Further, the surface of the inner peripheral side portion 2 0 a is magnet 1 9, a first outer peripheral side annular Li Bed 2 0 the as, the inner circumferential side annular rib 2 0 a _4, first of A predetermined number (24 in the illustrated example; but not limited to) of radial ribs 20 0 a laid between the outer annular rib 20 a ₃ and the inner annular rib 20 a ₄ _{And 5} . A first annular flange portion 20 a ₆ is formed on the first outer circumferential annular rib 20 a ₃ . Further, the inner peripheral side portion 2 0 a is the surface opposite to the magnet 1 9 side, and has a second outer peripheral side annular rib 2 0 a _7. A second annular flange portion 20 a ₈ is formed on the second outer peripheral annular ring 20 a ₇ . The inner peripheral edges of each N pole and S pole magnet 19 N, 19 S arranged in an annular shape by the first and second annular flange portions 20 a ₆ , 20 a ₈ Sandwich the part I have it.

[0035] The outer peripheral side 2 ° b is in close contact with the entire circumference of each of the N-pole and S-pole magnets 19 N, 19 S arranged in an annular shape, and these magnets 19 N, 1 Holds the outer surface of 9S.

[0036] Each of the connecting portions 20c has the same shape. That is, the connecting portion 20 c projects from the second annular flange portion 20 a _{8 of} the second outer circumferential annular rib 20 a ₇ to the outer diameter direction of the second annular flange portion 20 a _8. Radial connection ¾ | 5 2 0 ci (corresponding to the inner peripheral connection part of the present invention) and a substantially circumferential direction on the one side perpendicular to or substantially perpendicular to this radial connection part 2 0 c 1 (second A circumferential connecting portion 20 0 C 2 (corresponding to the outer peripheral side connecting portion of the present invention) that extends in a direction parallel to the tangential line of the annular flange portion 20 0 a ₈ and is connected to the outer peripheral side portion 2 Ob. It is configured. In this case, in this example, the length in the extending direction (that is, the radial direction) of the radial direction connecting portion 20 ci is relatively short, and the length in the extending direction (that is, the circumferential direction) of the circumferential direction connecting portion 20 c ₂ It is set short. Therefore, the connecting portion 20 c has a bent portion 20 c ₃ formed by the radial connecting portion 20 e and the circumferential connecting portion 20 c ₂ intersecting each other at a predetermined angle.

[0037] Each connecting portion 20c is arranged at equal intervals in the circumferential direction. Note that the connecting portions 20 c do not necessarily have equal intervals in the circumferential direction, and the arrangement intervals are arbitrary. However, in order to hold each N pole and S pole magnet 19 N, 19 S stably and firmly, it is desirable that the connecting portions 20 c be arranged at equal intervals in the circumferential direction.

[0038] The magnet holding member 20 has an inner peripheral side portion 20a, an outer peripheral side portion 20b, and a connecting portion 20c arranged in an annular shape by resin thin molding or insert molding. Each N pole and S pole magnet is formed on 1 9 N and 1 9 S. As the resin material of the magnet holding member 20, for example, POM (polyacetal), PP (polypropylene), phenol resin, nylon, or the like can be used.

[0039] In the rotary disk 1 4 of the rotation sensor 1 0 in this example, each of the connecting portions 2 0 c is radially from the second annular flange portion 2 0 a ₈ of the second outer peripheral side annular rib 2 0 a ₇ The circumferential direction connecting portion 20 c ₂ connected to the outer peripheral side portion 20 b is connected to the mysterious direction connecting portion 20 c protruding from In addition, since they are provided at predetermined intervals in the circumferential direction, the force applied to each N-pole and S-pole magnet 1 9 N, 19 S is suppressed by the contraction force of each connecting part 20 c .

[0040] That is, two directions of shrinkage direction of each connecting portion 2 0 c has a shrinking direction of the radial direction toward the radial connecting portion 2 0 c, a peripheral circumferential shrinkage direction of directional connecting portion 2 0 c ₂ become. As a result, as indicated by arrows in FIG. 2 (b), the force due to the contraction of each connecting portion 20c is equal to the radial force Fr due to the contraction of the radial connecting portion 20c and the circumferential connecting portion 20c. _It consists of the radial force F t due to the shrinkage of ₂ . At this time, since the length in the extending direction of the radial connecting portion 20 ci is relatively short, the amount of contraction of the radial connecting portion 20 is small, and the radial force F r is relatively small. Further, the circumferential Direction connecting portion 2 0 c extending direction of the length of _two relatively long and shrinkage of the circumferential connecting portion 2 0 c ₂ is relatively large, the circumferential connecting portion 2 0 c ₂ extending Since the length of each N pole and S pole magnet in the installation direction is relatively long and the cross-sectional area is large, the generated stress is relatively small. '

In addition, in the rotating disk 14 of this example, each connecting portion 20 c has a bent portion 20 c ₃ , so that when the magnet holding member 20 contracts, the circumferential connecting portion 20 c ₂ in the direction of the bizarre direction connecting portion 2 0 (circumferential connecting portion 2 0 c ₂ and the radial connecting portion 2 0 c and the bent portion 2 0 forms of c ₃ right angle or nearly right angle is large AMS1) Try to transform to open. When the magnet holding member 20 is contracted, the bending behavior of the bent portion 20 C 3 performs a cushioning action, so that the force caused by the contraction of each connecting portion 20 c is relieved.

[0042] Therefore, the force applied to each N pole S pole magnet 19 N, 19 S due to contraction of each connecting portion 20 c is further reduced. That is, the stress generated in each magnet 19 is also reduced by the cushioning action of the bent portion 20 c ₃ .

[0043] Further, when shrinkage of the magnet holding member 2 0, contraction of the inner peripheral side portion 2 0 a is between the inner circumferential side annular rib 2 0 a ₄ a first outer peripheral side annular rib 2 0 a ₃ Erected on It is suppressed by a predetermined number of radial ribs 20 as. As a result, the entire shrinkage of the magnet holding member 20 is also suppressed, so that the entire shrinking force of the magnet holding member 20 applied to each of the N pole and S pole magnets 19N and 19S (in particular, the inner peripheral side portion). The contraction force of 20a and the contraction force of outer peripheral side 20b) are also suppressed. Therefore, the stress generated in each magnet 19 by the overall contraction force of the magnet holding member 20 is reduced.

[0044] As shown by the two-dot chain line in FIGS. 2 (b) and 2 (c), two Hall elements 16 corresponding to the first Hall element 16a and the second Hall element 16b, which have come to predetermined positions, respectively. Attached to the bracket 15 at a predetermined interval along the circumferential direction of the annular magnet 19 so as to face the magnet 19. In that case, the circumferential distance between the two first and second Hall elements 16a, 16b is the circumferential distance between two adjacent magnets 19N, 19S (the circumferential center of the two magnets). (Odd distance + (1/2)) times (in the example shown, it is 3.5 times, but not limited to this).

[0045] The circumferential distance between the first and second Hall elements 16a, 16b is set to [even + (1/2) times the circumferential distance between the two magnets 19N, 19S. You can also In other words, the circumferential distance between the first and second Hall elements 16a and 16b should be set to [natural number + (1/2)] times the circumferential distance between the two magnets 19N and 19S. You can also. In the following description, as shown in FIG. 2 (c), the circumferential distance between the first and second Hall elements 16a and 16b is the odd number of the circumferential distance between the two magnets 19N and 19S. + (1/2)] It is assumed that it is set to double.

In addition, the first and second Hall elements 16 a and 16 b are disposed with a predetermined gap between them and the magnet 19 on the rotating disk 14.

As shown in FIG. 4, the first and second Hall elements 16 a and 16 b are both electrically connected to the controller 11. In the rotation sensor 10 of this example configured as described above, when the spool 4 rotates in the belt pulling direction, the first Hall element 16a becomes one of the N pole magnet 19N and the S pole magnet 19S. Figure 5 As shown in FIG. 4, a detection signal based on a current having a magnitude greater than or equal to a predetermined value is output to the controller 11. After that, when the spool 4 is further rotated 7.5 ° in the belt drawing direction, the 2nd Hall element 1 6 b detects one of the N pole magnet 19 N and the S pole magnet 19 S. Similarly, a detection signal based on current is output to the controller 11.

[0047] When the spool 4 further rotates in the belt drawing direction, as shown in FIG. 5, the first Hall element 1 6a does not detect the one magnet 19 and is turned off. Subsequently, the N pole magnet 1 9 N and S pole magnets 1 9 S detect one of the other magnets 19 Then, the first Hall element 16 a outputs a detection signal to the controller 11 by a current having a magnitude greater than a predetermined value having a polarity opposite to that described above. That is, the polarity of the current of the detection signal from the first hall element 16a is switched. After that, when the spool 4 further rotates 7.5 ° in the belt drawing direction, the second Hall element 16 b detects the other magnet 19 of the N pole magnet 19 N and S pole magnet 19 S, In the same way, a detection signal based on a current having a polarity opposite to that described above is output to the controller 11. In other words, the polarity of the current of the detection signal from the second hall element 16a is switched.

Then, the controller 11 detects the amount of rotation of the spool 4 by counting the number of switching of the polarity of the current of the detection signal from the first and second Hall elements 16 a, 16. Further, when the spool 4 rotates in the belt drawing direction, the phase of the detection signal from the first hall element 16a advances 7.5 ° ahead of the phase of the detection signal from the second hall element 16b. It is out. Therefore, when the detection of the magnet of the first Hall element 1 6a is switched from one of the N pole magnet 1 9 N and the S pole magnet 1 9 S to the other, the controller 1 1 If it is determined that 1 6 b detects either N pole magnet 19 N or S pole magnet 19 S, it is determined that the rotation direction of spool 4 is the belt drawing direction.

[0049] When the spool 4 rotates in the belt winding direction, the phase of the detection signal from the second Hall element 16b is 7.5% higher than the phase of the detection signal from the first Hall element 16a. ° Going forward. Therefore, the controller 1 1 1 Hall element 1 6 When the magnet detection of a N-pole magnet 1 9 N and S-pole magnet 1 9 S switches from one to the other, 2nd hall element 1 6 b becomes N-pole magnet 1 If it is determined that one of the 9 N and S pole magnets 1 9 S is detected, it is determined that the rotation direction of the spool 4 is the belt winding direction.

In this example, the circumferential width of each of the magnets 19 N and 19 S is 7.5 °, but the two first and second Hall elements 16 a and 16 b The rotation direction of the spool 4 is detected by setting the circumferential direction width of each magnet 19 N and 19 S to an angle smaller than the aforementioned 7.5 °, and setting this angle to the first and second holes. It can also be obtained by detecting with the elements 16a and 16b and calculating from the difference between the detected values.

According to the rotation sensor 10 of this example configured as described above, the magnet holding member 20 that holds each magnet 19 and transmits the rotation of the spool 4 to these magnets 19 is provided with a magnet. Since 1 9 is formed by resin-in molding or insert molding, each N pole and S pole magnet, 1 9 N, 19 S arranged in an annular shape can be stably constructed with a simple structure. The rotation of the spool 4 can be efficiently transmitted while being held. As a result, the rotation of the spool can be detected more accurately. In particular, since the magnet holding member 20 is formed of a lightweight resin, the inertia moment of the magnet holding member 20 can be reduced, and the rotation of the spool can be detected even more accurately.

[0052] Further, the magnet holding member 20 is supported by the rotating shaft 4a of the spool 4 and the inner peripheral edge of each of the N pole and S pole magnets 19 N and 19 S arranged in an annular shape. Inner peripheral side 20a to be held, each N-pole and S-pole magnet 19 N, 19 S outer peripheral side 20b to hold the outer peripheral surface, and inner peripheral side 20a and outer peripheral side 2 0 b and the connecting portion 20 c is further bent at a right angle or almost a right angle to the radial connecting portion 20 ci and the radial connecting portion 20 c. Since the circumferential connecting portion 20 c ₂ to be connected is formed, the shrinkage of the magnet holding member 20 that occurs during the resin effect during molding is reduced in the radial direction. It can be set in two directions: radial contraction of the connecting part 20 ci and circumferential contraction of the circumferential connecting part 20 c ₂ . Due to the circumferential contraction of the circumferential connecting portion 20 c ₂ , the contraction force of each connecting portion 20 c can be dispersed not only in the radial direction but also in the circumferential direction. Thereby, the stress generated in each N-pole and S-pole magnet 19 N, 19 S can be further reduced by the contraction force of each connecting portion 20 c. In addition, since the cross-sectional area of the magnet 19 in the direction of the contracting force dispersed in the circumferential direction is relatively large, the stress due to the contracting force dispersed in the circumferential direction can be effectively reduced. In addition, since the length of the extension direction of the mysterious direction connecting portion 20 ci is relatively short, the amount of contraction of the radial direction connecting portion 20 ci is reduced, and the radial force F r can be relatively reduced. .

[0053] Further, in the rotating disk 14 of this example, since each connecting portion 20c has a bent portion 20c3, when the magnet holding member 20 contracts, the circumferential connecting portion 20c ₂ behaves you'll deformed to to open in the direction of the radial connecting portions 2 0 ci can be performed on each of the connecting portions 2 0 c. Since the behavior of the bent portion 20 c ₃ that deforms acts as a cushion, the force caused by the contraction of each connecting portion 20 can be reduced.

Accordingly, the force applied to each N pole and S pole magnet 19 N, 19 S due to the contraction of each connecting portion 20 c is further reduced. Thus, the stress generated in each magnet 19 can also be reduced by the cushioning action of the bent portion 20 c ₃ .

[0055] Further, when shrinkage of the magnet holding member 2 0, the shrinkage of the inner peripheral side portion 2 0 a, between the inner circumferential side annular rib 2 0 a ₄ a first outer peripheral side annular rib 2 0 a ₃ It can be suppressed by a predetermined number of radial ribs 20 a ₅ installed on the wall. As a result, the entire contraction of the magnet holding member 20 is also suppressed, so that the total contracting force of the magnet holding member 20 applied to each N-pole and S-pole magnet 19 N, 19 S (Particularly, the contraction force of the inner peripheral side 20 a and the contraction force of the outer peripheral side 20 b) can also be suppressed. Therefore, the stress generated in each magnet 19 due to the entire contraction force of the magnet holding member 20 can be reduced. [0056] Thus, since the stress generated in each magnet 19 can be reduced even if the magnet holding member 20 is formed by resin in-mold molding or insert molding, the thickness of each magnet 19 is increased. You don't have to. This makes it possible to reduce the thickness of the rotation sensor i 0 (the length of the spool 4 in the axial direction) while holding each magnet 19 stably. Moreover, since it is not necessary to add a reinforcing material such as a filler to the resin of the magnet holding member 20 in order to cope with the generated stress, it is possible to prevent the physical properties of the resin from being changed by the added material.

In addition, according to the seat belt retractor 1 of this example configured as described above, the thickness of the rotation sensor 10 can be reduced, so that the seat belt retractor 1 is more effectively formed into a compact and compact. be able to. Therefore, it is possible to sufficiently and faithfully meet the demand for a wider cabin while reducing the overall outer shape of the vehicle required in recent years.

[0058] Further, since the rotation sensor 1.0 is arranged between the spring mechanism 7 and the power transmission mechanism 9 and is covered with these cases 17 and 18, the rotation sensor is detected by a noise signal from the outside. The effect on 10 can be prevented.

[0059] In the above-described example, the angle formed between the radial direction connecting portion 20 ci and the circumferential direction connecting portion 20 c ₂ in each connecting portion 20 c is not necessarily a right angle or a substantially right angle. If the direction connecting portion 20 c ₂ has a portion extending in the circumferential direction other than the radial direction, the angle can be set to an arbitrary angle. Further, the circumferential connecting portion 2 0 C 2 is, and FIG. 2 (b) in good be extended in the circumferential direction opposite to the example shown Le ^ that case, the circumferential connecting portion 2 0 c ₂ is either Even if it is extended in the circumferential direction on the same side, all of the circumferential connecting parts 20 0 c ₂ should extend in the circumferential direction on the same side. This is preferable in terms of more uniform distribution of the force applied to each magnet 19.

[0060] Further, the radial direction connecting portion 20 ct and the circumferential direction connecting portion 20 0 c ₂ may be provided opposite to the above example with respect to the inner peripheral side portion 20 0 a and the outer peripheral side portion 20 0 b. it can. In other words, the radial connecting portion 20 ct is provided on the outer peripheral side 2 side, and the circumferential connecting portion 20 0 c ₂

One Π — Can also be provided on the inner peripheral side 20a side. In this case, the angle formed by the radial connecting portion 20 and the circumferential connecting portion 20 c ₂ needs to be set larger than a right angle in order to connect the circumferential connecting portion 20 c ₂ to the inner peripheral side portion 20 a. is there.

FIG. 6 (a) shows a rotation sensor according to another example of the embodiment of the present invention, and is a rear view similar to FIG. 2 (b), and FIG. 6 (b) shows the ΉΒ-VBI line in FIG. (C) shows a rotation sensor in still another example of the embodiment of the present invention, and (b) is a rear view similar to FIG. 2 (b), and (d) is a VID-VID line in (c). FIG.

[0062] above in the example connecting portion 20 c of the predetermined number of circumferential direction is found provided at a predetermined interval, and although the bent portion 20 c ₃ of these connecting portions 20 c are as provided, FIG. 6 In the examples shown in (a) and (b), the connecting portion 20 c is provided by resin in-mold molding or insert molding over the entire circumference between the inner peripheral side portion 20 a and the outer peripheral side portion 20 b. The other configurations of the rotation sensor 10 and the seat belt retractor 1 in this example are the same as those in the above example.

[0063] The rotating disk 14 of this example also efficiently transmits the rotation of the spool 4 while stably holding the N-pole and S-pole magnets 19N, 19S arranged in an annular shape with a simple structure. be able to. Thereby, the rotation of the spool can be detected more accurately. In particular, since the magnet holding member 20 is made of a light amount of resin, the moment of inertia of the magnet holding member 20 can be reduced, and the rotation of the spool can be detected even more accurately. However, since the connecting portion 20c is provided over the entire circumference between the inner peripheral side portion 20a and the outer peripheral side portion 20b, a relatively large force F toward the center in the radial direction when the resin is cured F r may be added to the magnet 19 over the entire circumference. Therefore, the above example is preferred. Other functions and effects of the rotation sensor 10 and the seat belt retractor 1 in this example are the same as those in the example shown in FIGS. 1 to 5 described above.

[0064] Further, although it is assumed to be provided at a predetermined distance connecting portion 20 c of a predetermined number having a bent portion 20 c ₃ in the circumferential direction in the example above, shown in FIG. 6 (c) and (d) In the example, each connecting part 20c does not have a bent part and is simply a rotating disc. 14 is extended in the radial direction. The rotation sensor 10 and other configurations in this example are the same as the example shown in FIG. 2 (b). The other configuration of the seat belt retractor 1 in this example is the same as that in the above example.

In the rotating disk 14 of this example, the force applied to the magnet 19 when the resin is cured is smaller than in the example shown in FIGS. 6 (a) and 6 (b). However, in the region where the connecting portion 20 c is provided, each N pole and S pole magnet 19N, 19 S is applied with a relatively large force F r indicated by the arrow, so each N pole in this region And the stress generated in the S pole magnets 19N, 19 S increases. When the connecting portion 20c divided into a predetermined number is simply extended in the radial direction, the stress generated in each N-pole and S-pole magnet 19N, 19S may partially increase. Therefore, in order to suppress this force more effectively, the example shown in FIG. 2 (b) is preferable. Other functions and effects of the rotation sensor 10 and the seat belt retractor 1 of this example are the same as the examples shown in FIGS. 1 to 5 described above.

[0066] Figs. 7 (a) to (d) and Figs. 8 (a) to (d) show rotation sensors in other examples of the embodiment of the present invention, which are the same as those in Fig. 2 (b), respectively. It is a back view.

In the example shown in the aforementioned FIG. 2 (b) it is assumed that the bent portion 20 c ₃ to the connecting portion 20 c are al provided, in the example shown in FIG. 7 (a), bending the connecting portion 20 c. Parts 20 c ₃ is not provided. That is, the connecting portion 20c in this example is a connecting portion 20c that extends linearly in both the radial direction and the circumferential direction, and a predetermined number of these linear connecting portions 20c are predetermined in the circumferential direction. It is extended at intervals. In that case, in the connecting portion 20c in this example, a part of the connecting portion 20c does not exist in the radial direction, and a radially non-connecting portion is set. As shown in FIG. Are not set in the radial direction all the connecting portions. In this way, by setting the radially unconnected portion in the connecting portion 20c, the radial force applied to the magnet 19 when the resin contracts is more effectively suppressed. In this example, the connecting portion 20 c extends in both the radial direction and the circumferential direction, and therefore, the connecting portion between the inner peripheral side portion 20 a and the connecting portion 20 c and the outer peripheral side portion 20 a. And the connection portion of the connecting portion 2 0 c, same effects one Mari cushioning and bending section 2 0 c ₃ described above is obtained.

[0067] In the example shown in FIG. 7 (b), the entire radial connecting portion is set in a part of the connecting portion 20c as compared to the example shown in FIG. 7 (a). Thus, by setting the radial non-connecting portion in the connecting portion 20c, the radial force applied to the magnet 19 when the resin contracts becomes larger than the example shown in FIG. 7 (a). The shown to example in FIG. 7 (c), the inner peripheral side connecting portion 2 0 c I, the outer circumferential side connecting portion 2 0 c ₂ is extended both in the radial direction. Also, the bent portion 20 c ₃ between the inner peripheral side connecting portion 20 ci and the outer peripheral side connecting portion 20 c ₂ is formed in a semicircular arc shape, and the overall shape of the connecting portion 20 c is almost the same. It is formed in Ω shape. Since the bent portion 20 c ₃ is formed in the connecting portion 20 c in this example, the function and effect of the bent portion 20 c ₃ described above can be obtained. In the example shown in FIG. 7 (d), it is formed in an S shape with respect to the Ω-shaped connecting portion 20c in the example shown in FIG. 7 (c). Therefore, in this example, the bending portion 20 c ₃ is provided at two places, and the above-described operational effect by the bending portion 20 c ₃ can be obtained even more efficiently.

On the other hand, in the example shown in FIG. 8 (a), both the inner peripheral side connecting portion 20 c 1 and the outer peripheral side connecting portion 20 c ₂ are both radially and in comparison with the example shown in FIG. 2 (b). Extending in both directions in the circumferential direction, the connecting portion 20 c is formed in a “H” shape as a whole. Also, the inner peripheral side connecting portion 20 c and the outer peripheral side connecting portion 20 c ₂ inward (bending side) of the bent portion 2 0 c 3 between its inner peripheral surface an arcuate recess 2 0 c ₄ is provided. in this example, the aforementioned bent portion of the above by the recess 2 0 ₄ action effect according to 2 0 c ₃ is obtained may further more effectively. also, in this example, connecting unit 2 0 c from being extended in both the radial direction and the circumferential direction, the inner peripheral side portion 2 0 The same effect as that of the above-described bent portion 20 c ₃ , that is, the cushion effect can be obtained at the connection portion between a and the connecting portion 20 c and the connecting portion between the outer peripheral side portion 20 a and the connecting portion 20 c. The recess 2 0 C 4 is Zushi also not necessary to provide, can be omitted. However, it is preferable to provide a recess 2 0 c ₄ in order to obtain better further more efficiently effects caused by the bending section 2 0 c _3.

[00693 In the example shown in FIG. 8 (b), a predetermined number of connecting portions 20c are all formed in a diamond shape. Has been. Also in this example, the operation effect by the above-described bent portion 20 C 3 can be obtained more efficiently by the concave portion 20 c ₄ . In this example, since the connecting portion 20 c extends in both the radial direction and the circumferential direction, the connecting portion between the inner peripheral side portion 20 a and the connecting portion 20 c and the outer peripheral side portion 20 a are connected. The same effect as that of the above-described bent portion 20 c ₃ , that is, the cushion effect can be obtained at the connection portion with the portion 20 c.

In the example shown in FIG. 8 (c) ′, the connecting portion 20c in FIG. 7 (a) is formed in a curved shape with respect to the straight shape. In this example, in addition to the function and effect of the example of FIG. 7A described above, the same cushioning effect as that of the bent portion 20c can be obtained by the bending of the connecting portion 20c.

[0071] In the example shown in FIG. 8 (d), the connecting portion 20 in FIG. 8 (a) is formed in a “H” shape, whereas the connecting portion 20c “It is formed in the shape of a letter. In this example, the same effect as the effect of the example of FIG.

[0072] It should be noted that other configurations and other functions and effects of the rotation sensor 10 and the seat belt retractor 1 in the examples of Figs. 7 (a) to (d) and Figs. 8 (a) to (d) described above are described above. Example The same as the example shown in FIGS.

[0073] The seat belt retractor 1 of this example can be applied to a motor retractor used in a conventionally known seat belt device. For example, as shown in FIG. 9, the seatbelt retractor 1 of this example includes a seatbelt retractor 1 fixed to the vehicle body, a belt belt retractor 1 that is pulled out from the seatbelt retractor 1 3 a is the seat belt 3 fixed to the floor of the vehicle body or the vehicle seat 21, the guide belt force for guiding the seat belt 3 pulled out from the seat belt retractor 1 toward the occupant's shoulder 22, this guide force (1) Consists of a tread 23 supported slidably on a seat belt 3 guided from 22 and a buckle 24 fixed to a floor of a vehicle body or a vehicle seat 21 and detachably inserted into an evening 23 There are 25 seat belt devices that are played.

[0074] Thus, the seat belt retractor 1 of this example is replaced with the seat belt device 2 By applying this to 5, the passenger can be restrained efficiently with the seat belt 3 over a long period of time, depending on the vehicle running situation and the usage situation of the seat belt device 25. Industrial applicability

A seat belt retractor and a seat belt apparatus according to the present invention include a seat belt retractor configured as a motor retractor that performs belt winding and belt withdrawal by controlling the rotation of a spool in an electric motor, and a seat belt apparatus including the same. In particular, it can be suitably used for a seat belt retractor provided with a rotation amount detecting means for detecting the amount of rotation of a spool and a seat belt device using the same.

Claims

The scope of the claims

1. a spool that winds up a seat belt; a drive unit that rotates the spool; and a rotation amount detection unit that detects a rotation amount of the spool, and the rotation of the spool detected by the rotation amount detection unit In the seat belt retractor in which the amount of rotation by the spool is controlled by controlling the driving means based on the amount,

The rotation amount detecting means is a rotating disk provided so as to be integrally rotatable with the spool, and is arranged in a predetermined annular shape concentrically with the rotating disk with alternating N pole magnets and S pole magnets. A rotating disk having a number of magnets and a magnet holding member for holding the predetermined number of magnets, and a magnetic detection means for detecting a magnet located at a predetermined position out of the predetermined number of magnets, A seat belt retractor wherein the magnet holding member is made of resin.

2. The magnet holding member includes an inner peripheral side portion positioned on an inner peripheral side of the annular magnet, an outer peripheral side portion positioned on an outer peripheral side of the annular magnet, and an inner peripheral side portion and an outer peripheral side thereof. Consisting of connecting parts that connect parts,

The magnet holding member is characterized in that the inner peripheral side portion, the outer peripheral side portion, and the connecting portion are integrally formed with the annular magnet by in-mold molding or insert molding. The seat belt retractor according to claim 1.

3. The radial non-connection portion is set, wherein a part of the connection portion does not exist in a radial direction between the inner peripheral side portion and the outer peripheral side portion. Seat bell.

4. The connecting portion includes an inner peripheral side connecting portion connected to the inner peripheral side portion, an outer peripheral side connecting portion that is connected to the inner peripheral side connecting portion and is connected to the outer peripheral side portion, and 4. The seat belt retractor according to claim 2, comprising a bent portion between an inner peripheral side connecting portion and the outer peripheral side portion.

5. The magnet holding member according to any one of claims 2 to 4, wherein the magnet holding member has a predetermined number of radial ribs arranged at predetermined intervals in the circumferential direction on the inner peripheral side portion. The described seat belt retractor.

6. At least a seat belt retractor that winds up the seat belt, a tanda that is slidably supported by the seat belt pulled out from the seat belt retractor, and a buckle that is detachably engaged with the evening belt. A seatbelt device for restraining an occupant by the seat bell rod,

The seat belt apparatus according to any one of claims 1 to 5, wherein the seat belt retractor is a seat belt retractor.