Buckle and seat belt device

Abstract

Provided are a buckle in which the cost for attaching a wire to a base can be reduced, and a seat belt device including the buckle. A buckle 1 comprises: a latch member 3 that locks to an inserted tongue 56 to latch the tongue 56; an operating button 12 for releasing the latching of the tongue 56 by the latch member 3; a base 4 that has a bottom surface portion 40 and a pair of side wall portions 41 rising from lateral-direction side edge parts of the bottom surface part 40 and that pivotably supports the latch member 3; a fastening member 8 that employs a wire W to connect the base 4 to a vehicle body member; a pulley plate 80 that is disposed on the bottom surface portion 40 and around which the wire W is wound and which locks the wire W; and a rivet R that attaches the pulley plate 80 to the bottom surface portion 40.

Description

Buckle and Seat Belt Device

[0001] The present invention relates to a seat belt device equipped on a seat of an automobile or the like, and a buckle for this seat belt device.

[0002] In general, a vehicle such as an automobile is provided with a seat belt device that restrains an occupant on a seat, which includes a seat bottom (seat cushion) where the occupant sits and a backrest part (seat back) located on the back of the occupant. The seat belt device includes a webbing that restrains the occupant, a retractor that winds up the webbing, a buckle disposed on the side of the seat, and a tongue disposed on the webbing, and restrains the occupant on the seat by fitting the tongue into the buckle.

[0003] A conventional buckle has a latch member that enters a locking hole of an inserted tongue to lock the tongue, an ejector that presses the tongue in a direction to release it from the buckle when the latch member releases the locking with the tongue, and a member such as an ejector spring that constantly biases the ejector in a direction for the tongue to disengage from the buckle. These members are attached to a base formed of a U-shaped frame having a pair of side walls and a bottom.

[0004] The buckle is fastened and fixed to the vehicle body side by attaching one end of a fastening wire to the base and the other end to a vehicle body member (vehicle or seat). Conventionally, three parts, a wire plate, a rivet, and a pulley of a forged product, are used to attach the wire to the base, resulting in high costs (see, for example, Patent Document 1).

[0005] Japanese Patent Application Laid-Open No. 2003-127829

[0006] The present invention has been made in view of the above conventional situation, and an object thereof is to provide a buckle that can reduce the cost of attaching a wire to a base, and a seat belt device including this buckle.

[0007] The buckle of the present invention comprises a latch member that engages with an inserted tongue to latch the tongue, an operating button for releasing the latch of the tongue by the latch member, a base having a first bottom surface and a pair of side walls rising from the short-side edges of the first bottom surface, which rotatably supports the latch member, a fastening member using a wire that connects the base to a vehicle body member, a pulley plate disposed on the first bottom surface around which the wire is wound and which locks the wire, and a rivet for attaching the pulley plate to the first bottom surface.

[0008] In one aspect of the present invention, a first opening is formed in each of the pair of side wall portions, a second opening is formed in the first bottom portion through which the rivet is inserted, the pulley plate has a second bottom portion, a peripheral wall portion rising from a part of the peripheral edge of the second bottom portion, and a claw portion extending outward from a part of the upper edge of the peripheral wall portion, the wire is sandwiched between the peripheral wall portion and the claw portion, and a third opening is formed in the second bottom portion through which the rivet is inserted.

[0009] In one aspect of the present invention, a portion of the claw portion enters the first opening.

[0010] The seat belt device of the present invention comprises a seat belt to be worn by an occupant, a tongue movably supported by the seat belt, and a buckle of the present invention to which the tongue is locked.

[0011] According to the present invention, the cost of attaching the wire to the buckle base can be reduced.

[0012] This is a schematic diagram of a seat belt device equipped with a buckle according to an embodiment of the present invention. This is an exploded view of the components of the buckle according to the same embodiment. This is a perspective view of the base according to the same embodiment. This is an enlarged perspective view of the base. This is a diagram showing a pulley plate and rivets for attaching a wire to the base. This is a perspective view of the pulley plate. This is a perspective view of the pulley plate. This is a top view of the pulley plate. This is a bottom view of the pulley plate. This is a perspective view of the base to which the wire is attached. This is a perspective view of the base to which the wire is attached. Figure 12A is a top view of the base to which the wire is attached, and Figure 12B is a cross-sectional view taken along line B-B in Figure 12A.

[0013] Embodiments of the present invention will be described below with reference to the drawings.

[0014] As shown in Figure 1, the seat belt device 50 is basically a conventionally known three-point seat belt device and comprises a seat belt retractor 53 disposed near the vehicle seat 2, a seat belt 54 that is retractably wound onto the seat belt retractor 53 and whose end belt anchor 54a is fixed to the floor of the vehicle body or the vehicle seat 2, a guide anchor 55 that guides the seat belt 54 pulled out from the seat belt retractor 53 toward the occupant's shoulder, a tongue 56 that is slidably supported on the seat belt 54 that has been guided from the guide anchor 55, a buckle 1 into which the tongue 56 is detachably inserted and locked, and a fastening member 8 that fixes the buckle 1 to a vehicle body member (vehicle floor or vehicle seat 2).

[0015] Figure 2 is an exploded view of the buckle 1. The buckle 1 is configured to be detachably attached to the tongue 56 of the seat belt device 50 that restrains the occupant to the vehicle seat 2, and includes a latch member 3 having a claw portion that can engage with the opening 56a of the tongue 56.

[0016] The buckle 1 also includes an upper cover 11 having an insertion opening for the tongue 56, an operating button 12 for releasing the engagement of the latch member 3, a base 4 that movably supports the latch member 3 and the operating button 12, a lower cover 14 connected to the upper cover 11 and housing the base 4, a lock pin 15 supported by the base 4 that restrains the movement of the latch member 3 engaged with the tongue 56 in the release direction, an ejector 16 slidably positioned in the longitudinal direction of the base 4 and capable of biasing the tongue 56 in the direction of detaching it from the buckle 1, and a metal lever 18 (inertia lever) rotatably supported by the base 4 that prevents the movement of the operating button 12 when the operating button 12 receives an inertial force in the release direction when the tongue 56 is engaged with the latch member 3.

[0017] Furthermore, the buckle 1 is provided with a slider 34 that is slidably positioned on the upper surface of the latch member 3. The slider 34 has a pair of arms that extend in the lateral direction of the buckle 1, and the arms are configured to be able to be locked onto the operation button 12.

[0018] When the tongue 56 is inserted into the opening of the upper cover 11, the ejector 16 is pushed in by the tongue 56, causing the ejector 16 to rotate in a direction that engages the latch member 3 with the tongue 56. As the latch member 3 rotates, the slider 34 also rotates, and the slider 34, which was restrained by the side of the lock pin 15, slides under the lock pin 15 due to the biasing force of the slider spring 35. Through this operation, the latch member 3 engages with the opening 56a of the tongue 56, and the tongue 56 can be restrained by the buckle 1.

[0019] On the other hand, to release the tongue 56, pressing the operation button 12 pushes in the slider 34, which is then pushed out from below the lock pin 15. Consequently, the latch member 3 rotates in the disengagement direction, and the opening 56a of the tongue 56 is released from the latch member 3. The tongue 56 is then ejected to the outside of the buckle 1 via the ejector 16 by the biasing force of the ejector spring 17.

[0020] As shown in Figures 2 to 4, the base 4 is a U-shaped frame having a pair of side wall portions 41 that rotatably support the latch member 3, and a bottom portion 40 (first bottom portion) that connects the pair of side wall portions 41. The bottom portion 40 is a rectangular member in plan view with a plurality of openings formed therein, and the side wall portions 41 rise from a pair of side edges at both ends in the short direction. The side wall portions 41 are parallel to the longitudinal direction of the base.

[0021] The side wall portion 41 has a support groove 42, a support hole 43, an engagement groove 44, a support groove 45, and an opening 46 (first opening) formed in order from one end (tongue insertion side) to the other end in the longitudinal direction. The support groove 42 rotatably supports the pivot shaft of the lever 18. The support hole 43 supports the lock pin 15, into which the end of the lock pin 15 is inserted. The engagement groove 44 supports the slider 34 so that the engagement shaft of the slider 34 is engaged, allowing the slider 34 to move within the engagement groove 44. The support groove 45 rotatably supports the latch member 3. The lower end of the opening 46 reaches the bottom surface portion 40.

[0022] A retaining hole 47 extending in the longitudinal direction of the base 4 is formed in the bottom portion 40, and the ejector 16 is slidably positioned in the retaining hole 47. An ejector spring is also positioned in the retaining hole 47 to bias the ejector 16. A protrusion 47a is formed at the edge of the retaining hole 47, and the protrusion 47a is inserted inside one end of the ejector spring 17. The other end of the ejector spring 17 is attached to the ejector 16.

[0023] An opening 48 (second opening) is formed at the longitudinal end of the bottom portion 40 (the end opposite to the tongue insertion opening). The opening 48 is, for example, circular. The opening 48 is located between the lower ends of the pair of openings 46.

[0024] As shown in Figures 1 and 5, the buckle 1 is connected to the vehicle body member by a fastening member 8. The fastening member 8 has a loop-shaped wire W and a bracket connected to the wire W, with the wire W attached to the base 4 and the bracket attached to the vehicle body member.

[0025] For attaching the wire W to the base 4, a pulley plate 80 and a rivet R are used, around which the wire W is wound and which is secured to the wire W. The pulley plate 80 is manufactured, for example, by pressing and heat-treating iron.

[0026] As shown in Figures 6 to 9, the pulley plate 80 has a flat bottom portion 81 (second bottom portion), a peripheral wall portion 82 rising from the periphery of the bottom portion 81, and two claw portions 83 extending from a part of the upper edge of the peripheral wall portion 82.

[0027] An opening 81a (third opening) is formed in the center of the bottom surface 81. The bottom surface 81 is roughly semi-elliptical in plan view and is surrounded by an edge 81b that is parallel to the shorter side of the base 4 when installed on the base 4, a pair of straight sections 81c that extend perpendicularly from both ends of the edge 81b, and a semi-circular curved section 81d that connects the ends of the pair of straight sections 81c. A peripheral wall 82 rises from the pair of straight sections 81c and the curved section 81d on the periphery of the bottom surface 81b.

[0028] The peripheral wall portion 82 is curved upwards in a convex shape, becoming more outward towards the top (in the direction away from the center of the bottom surface portion 81).

[0029] The claw portion 83 extends outward from a part of the upper edge of the peripheral wall portion 82 and is curved upward convexly so that the tip is downward. The claw portion 83 is formed on the outer edges of both ends of the curved portion 81d that is connected to the straight portion 81c, on the periphery of the bottom surface portion 81, as shown in Figures 8 and 9.

[0030] The groove between the outer circumferential surface of the peripheral wall portion 82 and the inner circumferential surface of the claw portion 83 becomes the area where the wire W is placed.

[0031] As shown in Figures 10, 11, 12A, and 12B, the U-shaped portion of the wire W is sandwiched between the peripheral wall portion 82 and the claw portion 83 of the pulley plate 80. Then, the pulley plate 80 is placed on the bottom surface portion 40 of the base 4, the opening 81a of the pulley plate 80 is aligned with the opening 48 of the base 4, and rivets R are inserted through the openings 81a and 48 and crimped to fix the pulley plate 80 and the base 4. This fixes the wire W to the base 4. At this time, a part of the claw portion 83 of the pulley plate 80 enters the opening 46 of the side wall portion 41 of the base 4.

[0032] When a load is applied to the wire W in a direction that pulls it out of the base 4, a portion of the load on the wire W is transmitted to the bottom surface 40 of the base 4 via the bottom surface 81 of the pulley plate 80 and the rivet R. In addition, a portion of the load on the wire W is transmitted to the side wall 41 of the base 4 via the claw portion 83 of the pulley plate 80. This makes it easier for the load to be transmitted to the base 4 and suppresses deformation of the pulley plate 80.

[0033] In this embodiment, the wire W is attached to the base 4 using only two parts: a rivet R and a pulley plate 80 that can be manufactured by press working and heat treatment. This reduces costs compared to using three parts, including a forged pulley, as is done in the past.

[0034] The present invention is not limited to the embodiments described above, and various modifications are possible without departing from the spirit of the invention. For example, the buckle 1 may be connected to the buckle pretensioner by a fastening member 8.

[0035] This application is based on Japanese Patent Application No. 2025-007007, filed on 17 January 2025, which is incorporated herein by reference in its entirety.

[0036] 1 Buckle 3 Latch member 4 Base 8 Fastening member 12 Operation button 50 Seat belt device 56 Tongue 80 Pulley plate R Rivet W Wire

Claims

1. A buckle comprising: a latch member that engages with and latches an inserted tongue; an operating button for releasing the latch of the tongue by the latch member; a base having a first bottom surface and a pair of side walls rising from the short-side edges of the first bottom surface, which rotatably supports the latch member; a fastening member using a wire that connects the base to a vehicle body member; a pulley plate disposed on the first bottom surface around which the wire is wound and which locks the wire; and a rivet for attaching the pulley plate to the first bottom surface.

2. The buckle according to claim 1, wherein a first opening is formed in each of the pair of side wall portions, a second opening is formed in the first bottom portion through which the rivet is inserted, the pulley plate has a second bottom portion, a peripheral wall portion rising from a part of the peripheral edge of the second bottom portion, and a claw portion extending outward from a part of the upper edge of the peripheral wall portion, the wire is sandwiched between the peripheral wall portion and the claw portion, and a third opening is formed in the second bottom portion through which the rivet is inserted.

3. The buckle according to claim 2, wherein a portion of the claw portion enters the first opening.

4. A seat belt device comprising: a seat belt to be worn by an occupant; a tongue movably supported by the seat belt; and a buckle according to any one of claims 1 to 3 to which the tongue is locked.

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