Vehicle seat locking device

Abstract

To provide a vehicular seat lock device which achieves simplification of the structure and can change a backrest angle of a seat back in two steps at a first position and a second position.SOLUTION: A latch 12 may rotate from an unlatch position to a first latch position by engagement of a leg part 51 of a striker 5 entering a striker entering groove 71 with an engagement groove 123 and rotates toward a second latch position by movement of a second auxiliary arm 192 in conjunction with rotation of an engagement auxiliary lever 19 to a restriction position. The leg part 51 of the striker 5 is released from the engagement groove 123 to be sandwiched between the engagement auxiliary lever 19 and a tip 125 of a third arm part 124 by rotation of the latch 12 to the second latch position.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a vehicle seat locking device, and more particularly to a vehicle seat locking device capable of changing the reclining angle of a seat back in two stages.

Background Art

[0002] Conventionally, in a vehicle seat locking device, in a vehicle seat, for example, in a vehicle seat, a locking mechanism provided on a seat back rotatably supported with respect to a vehicle body is engaged with a striker fixed to the vehicle body, whereby the reclining angle of the seat back can be changed in two stages between a first position and a second position.

[0003] For example, in Patent Document 1, a striker fixed to the vehicle body side and having a first rod-shaped engaging portion and a second rod-shaped engaging portion, and a base plate fixed to the seat back are rotatably supported by a first shaft, and a first front contact surface portion that contacts a portion of the first rod-shaped engaging portion on the side opposite to the falling direction of the seat back in the first position of the seat back, and a second front contact surface portion that contacts a portion of the second rod-shaped engaging portion on the side opposite to the falling direction of the seat back in the second position of the seat back. A first hook plate, a second hook plate rotatably supported by a first shaft on the base plate, and having a first rear contact surface portion that contacts a portion of the first rod-shaped engaging portion in the falling direction of the seat back in the first position of the seat back, and a second rear contact surface portion that contacts a portion of the second rod-shaped engaging portion in the falling direction of the seat back in the second position of the seat back, and a pole rotatably supported by a second shaft on the base plate and engaging with the first hook plate to stop the rotation of the first hook plate, and a cam that rotates in conjunction with the pole, are provided, and a vehicle seat locking device capable of changing the seat back in two stages between a first position and a second position is disclosed.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

SUMMARY OF THE INVENTION

PROBLEMS TO BE SOLVED BY THE INVENTION

[0005] However, the vehicle seat lock device disclosed in Patent Document 1 can change the reclining angle of the seat back in two stages, namely, a first position and a second position. Therefore, since the elements that engage with the first rod-shaped engaging portion and the second rod-shaped engaging portion of the striker are constituted by two parts, namely, a first hook plate and a second hook plate, it has a problem of having a large number of parts and a complicated configuration.

[0006] In view of the above problems, an object of the present invention is to provide a vehicle seat lock device that simplifies the configuration and enables the reclining angle of the seat back to be changed in two stages, namely, a first position and a second position.

MEANS FOR SOLVING THE PROBLEMS

[0007] According to the present invention, the above problems are solved as follows. In a vehicle seat lock device, a striker attached to either the vehicle body or the seat back, a base plate attached to the other of the vehicle body or the seat back and having a striker entry groove in which a leg portion provided on the striker can move forward and backward as the seat back operates, a latch supported by the base plate so as to be rotatable by a latch shaft at a predetermined angle and rotatable from an unlatch position via a first latch position to a second latch position and vice versa, and having an engagement groove engageable with the leg portion that has entered the striker entry groove, a first arm portion provided on the latch direction side of the engagement groove, a second arm portion provided on the unlatch direction side of the engagement groove, and a latch having a third arm portion provided between the engagement groove and the second arm portion, a ratchet supported by the base plate so as to be rotatable by a ratchet shaft at a predetermined angle and biased in the engagement direction by a spring, and having a restraining portion that can restrain the latch in the first latch position by engaging with the first arm portion and can restrain the latch in the second latch position by engaging with the second arm portion, and an engagement auxiliary lever supported by the base plate so as to be rotatable by a shaft at a predetermined angle and having a first auxiliary arm portion against which the leg portion that has entered the striker entry groove can abut, and a second auxiliary arm portion that rotates from a standby position toward a restraining position when the leg portion abuts against the first auxiliary arm portion and can abut against the latch in the latch direction by the rotation, wherein the latch is rotatable from the unlatch position to the first latch position when the leg portion that has entered the striker entry groove engages with the engagement groove, and is rotatable toward the second latch position by the movement of the second auxiliary arm portion accompanying the rotation of the engagement auxiliary lever to the restraining position, and the leg portion of the striker is characterized in that it comes out of the engagement groove and is sandwiched between the engagement auxiliary lever and the tip of the third arm portion when the latch rotates to the second latch position.

[0008] Preferably, the engagement auxiliary lever rotates the latch to a position before the second latch position by the second auxiliary arm portion abutting against a pressed portion provided on the latch.

[0009] Preferably, the meshing auxiliary lever stops at the restraint position when the first auxiliary arm portion abuts against the base plate.

[0010] Preferably, the portions of the first auxiliary arm portion of the meshing auxiliary lever that abut against the first leg portion of the striker and the base plate are made of synthetic resin or an elastic body.

[0011] Preferably, the meshing groove of the latch is in a position overlapping the striker entry groove when the latch is in a position between the unlatch position and in front of the second latch position, and retracts to a position not overlapping the striker entry groove when the latch is in the second latch position.

[0012] Preferably, the ratchet has a cam portion that abuts against the second arm portion of the latch by the biasing force of the spring, and forcibly rotates the latch from a position in front of the second latch position to the second latch position.

[0013] Preferably, the ratchet includes a first ratchet rotatably supported by the ratchet shaft at a predetermined angle, and a second ratchet rotatably supported by the ratchet shaft independently of the first ratchet at a predetermined angle. The first ratchet has an engaging portion that prevents rotation of the latch in the unlatch direction from the first latch position of the latch by engaging with the first arm portion, and prevents rotation of the latch in the unlatch direction from the second position of the latch by engaging with the second arm portion. The second ratchet has a hook portion that prevents rotation of the latch in the latch direction from the first latch position of the latch by engaging with the first arm portion.

[0014] Preferably, the cam portion of the ratchet is continuously formed on the engaging portion of the first ratchet.

[0015] Preferably, the striker entry groove has an opening width that is at least twice or more the thickness of the leg portion of the striker.

Advantages of the Invention

[0016] According to the present invention, by using a single latch as the element that meshes with the striker, the reclining angle of the seat back can be changed in two stages, namely the first position and the second position, while reducing the number of parts and simplifying the configuration.

Brief Description of the Drawings

[0017]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

Figure 15

Figure 16

Figure 17

Embodiment for Carrying out the Invention

[0018] Hereinafter, an embodiment according to the present invention will be described with reference to the drawings. As shown in FIG. 1, the rear seat 2 to which the vehicle seat lock device 1 according to the present invention is attached includes a seat cushion 3A installed on the vehicle body floor, and a seat back 3B supported by a hinge shaft (not shown) facing the left-right direction at the lower rear end of the seat cushion 3A so as to be tiltable back and forth.

[0019] The vehicle seat lock device 1 includes a locking mechanism 4 attached to the seat back 3B side and a striker 5 fixed to the vehicle body side. When the seat back 3B is in the upright position, the locking mechanism 4 engages with the striker 5, so that the reclining angle of the seat back 3B can be changed in two steps between a first position shown by a solid line in FIG. 1 and a second position shown by a two-dot chain line inclined rearward from the first position.

[0020] The seat back 3B is selectively held in either the first position or the second position as described above, and based on the operation of the operation member 6 provided on the shoulder of the seat back 3B, the engagement between the locking mechanism 4 and the striker 5 is released, so that it can be moved to a reclined position reclined forward as shown by the two-dot chain line in FIG. 1.

[0021] As can be understood from FIG. 1, the striker 5 has an engagement rod (not numbered) that is substantially U-shaped in plan view and is fixed to the vehicle body side facing the side surface of the seat back 3. The engagement rod has a front first leg portion 51 and a rear second leg portion 52 that is spaced a predetermined amount rearward from the first leg portion 51.

[0022] As shown in FIGS. 2 to 5, the lock mechanism 4 includes a metal base plate 7 fixed to a seat frame 31B (see FIG. 5) inside the seat back 3B, a ratchet including a first ratchet 9 and a second ratchet 10 that are supported by a ratchet shaft 8 facing in the left-right direction on the base plate 7 and are rotatable by a predetermined angle, a latch 12 that is supported by a latch shaft 11 facing in the left-right direction on the base plate 7 and is rotatable by a predetermined angle, and an engagement auxiliary lever 19 that is supported by a shaft 18 facing in the left-right direction on the base plate 7 and is rotatable by a predetermined angle. Thus, as will be described later, by arranging the first and second ratchets 9 and 10 and the engagement auxiliary lever 19 above the striker entry groove 71 in the base plate 7 and arranging the latch 12 below the striker entry groove 71, the dimensions of the lock mechanism 4 in the front-rear direction in particular are reduced, enabling miniaturization.

[0023] The base plate 7 is made of metal and has a striker entry groove 71 that is open at the rear so that when the seat back 3B is actuated, the first and second leg portions 51 and 52 of the striker 5 can advance and retreat in the front-rear direction at a substantially central portion in the up-down direction.

[0024] The opening width in the up-down direction of the striker entry groove 71 of the base plate 7 is set to be about 2 to 3 times the thickness (diameter) of the first leg portion 51 and the second leg portion 52 of the striker 5. Thus, even if the entry position of the striker 5 with respect to the striker entry groove 71 of the base plate 7 is displaced in the up-down direction from the reference position due to an attachment position error of the rear seat 2, play in the movable part of the seat back 3B, etc., as shown in FIGS. 6 to 17, if the displacement of the movement trajectories of the first and second leg portions 51 and 52 of the striker 5 is within a predetermined allowable range, the entry of the first and second leg portions 51 and 52 of the striker 5 into the striker entry groove 71 is allowed.

[0025] In FIGS. 6 to 17, the first and second leg portions 51 and 52 shown by solid lines indicate the reference positions, and the first and second leg portions 51a and 52a (see FIG. 6) shown by two-dot chain lines indicate positions shifted in the vertical direction from the reference positions due to the mounting position error of the rear seat 2, the play of the movable portion of the seat back 3B, etc. Further, the path X (see FIG. 6) shown by a one-dot chain line indicates the reference entry locus of the first and second leg portions 51 and 52 with respect to the striker entry groove 71 of the base plate 7 at the reference position, and the paths X1 and X2 (see FIG. 6) shown by one-dot chain lines indicate the entry loci of the first and second leg portions 51a and 52a with respect to the striker entry groove 71 of the base plate 7 in the state where a shift has occurred.

[0026] The base plate 7 is fixed to the seat frame 31B by a plurality of bolts 32B inserted into a flange-shaped cylindrical support portion 16 fixed to the front upper portion of the base plate itself, and first and second shaft portions 8 and 11 having the same shape as the support portion 16, respectively. Specifically, as shown in FIG. 5, in a state where the flange portions 16a, 8a, and 11a of the support portion 16, the first and second shaft portions 8 and 11 are in contact with the surface of the seat frame 31B, it is fixed to the seat frame 31B by a plurality of bolts 32B.

[0027] The first ratchet 9 is made of metal and is supported by a ratchet shaft 8 so as to be rotatable by a predetermined angle above the striker entry groove 71 in the base plate 7, and is biased in the engagement direction (counterclockwise in FIG. 3 and clockwise in FIG. 4) by a spring 13 supported by the ratchet shaft 8. The first ratchet 9 is connected to the operating member 6 via an operating force transmission member 14 movable in the vertical direction. Thereby, the first ratchet 9 rotates by a predetermined angle in the release direction (clockwise in FIG. 3 and counterclockwise in FIG. 4) against the biasing force of the spring 13 about the ratchet shaft 8 in conjunction with the operation of the operating member 6.

[0028] The second ratchet 10 is supported by a ratchet shaft 8 so as to be rotatable by a predetermined angle independently of the first ratchet 9 above the striker entry groove 71 in the base plate 7, and is biased in the engaging direction (counterclockwise in FIG. 3 and clockwise in FIG. 4) by a spring 15 supported by a support portion 16 in the base plate 7, and rotates in the release direction as the first ratchet 9 rotates in the release direction. The rotation of the second ratchet 10 in the release direction accompanying the rotation of the first ratchet 9 in the release direction is achieved by a protrusion 93 provided on the first ratchet 9 coming into contact with an arm portion 102 provided on the second ratchet 10 from the release direction.

[0029] The meshing auxiliary lever 19 is made of synthetic resin and is supported by a shaft 18 so as to be rotatable by a predetermined angle above the inner part of the striker entry groove 71 in the base plate 7, and is biased in the standby direction (for example, counterclockwise in FIGS. 3 and 6 and clockwise in FIG. 4) by a spring 20 supported by the shaft 18, and is normally held in a standby position shown in FIGS. 3, 4, and 6 where the upper part 19a abuts against the base plate 7.

[0030] Furthermore, the meshing auxiliary lever 19 has a first auxiliary arm portion 191 extending downward and a second auxiliary arm portion 192 extending forward in the standby position. As the first leg portion 51 of the striker 5 enters the striker entry groove 71, when the first leg portion 51 abuts against the first auxiliary arm portion 191, the meshing auxiliary lever 19 rotates by a predetermined angle in the entry direction (for example, clockwise in FIGS. 3 and 6 and counterclockwise in FIG. 4) against the biasing force of the spring 20 from the standby position and stops at a restraint position shown in FIG. 15.

[0031] The first auxiliary arm portion 191 extends downward so as to overlap the striker entry groove 71 in the left - right direction at the standby position, and has a first contact portion 191a provided on the side opposite to the entry direction of the first leg portion 51 of the striker 5, and a second contact portion 191b provided on the opposite side of the first contact portion 191a and opposite to a part of the base plate 7. Thereby, when the first leg portion 51 of the striker 5 enters the striker entry groove 71 and the first leg portion 51 contacts the first contact portion 191a at a predetermined position, the meshing auxiliary lever 19 rotates from the standby position to the restraint position. When the meshing auxiliary lever 19 rotates to the restraint position, the second contact portion 191b contacts the base plate 7, so that the further rotation of the meshing auxiliary lever 19 is blocked and it stops at the restraint position. Preferably, in a state where the first leg portion 51 contacts the first contact portion 191a of the first auxiliary arm portion 191 and the second contact portion 191b of the first auxiliary arm portion 191 contacts the base plate 7, the first contact portion 191a and the second contact portion 191b are formed with a thickness such that they can be elastically deformed slightly in the entry direction of the striker 5. Thereby, it becomes possible to reduce the contact sound when the first leg portion 51 of the striker 5 contacts the first contact portion 191a of the first auxiliary arm portion 191. Furthermore, it also becomes possible to reduce the contact sound when the second contact portion 191b of the first auxiliary arm portion 191 contacts the base plate 7.

[0032] The second auxiliary arm portion 192 is located above the striker entry groove 71 at the standby position of the meshing auxiliary lever 19. When the meshing auxiliary lever 19 rotates from the standby position in the entry direction, it contacts and presses a later - described pressed portion 127 provided on the latch 12 at a predetermined position, thereby forcibly rotating the latch 12 in the latch direction.

[0033] The latch 12 is supported by a latch shaft 11 on the base plate 7 so as to be rotatable by a predetermined angle below the striker entry groove 71, and is biased in the unlatch direction (clockwise in FIG. 3 and counter - clockwise in FIG. 4) by a spring 17 supported by the latch shaft 11.

[0034] Further, when the seat back 3B is in a position other than the first position and the second position and the striker 5 has not entered the striker entry groove 71 of the base plate 7, the latch 12 stops at the unlatch position shown in FIG. 6. As the striker 5 enters the striker entry groove 71 along with the upright movement of the seat back 3B, it rotates against the biasing force of the spring 17 by a predetermined angle in the latch direction (counterclockwise in FIG. 6) from the unlatch position to the first latch position shown in FIG. 10 and stops at that position. Further, it rotates by a predetermined angle in the latch direction from the first latch position to the second latch position shown in FIG. 15 and stops. Also, it rotates in the reverse unlatch direction along with the reclining movement of the seat back 3B based on the operation of the operation member 6.

[0035] The first latch position of the latch 12 corresponds to the first position of the seat back 3B and the striker 5. Similarly, the second latch position corresponds to the second position of the seat back 3B and the striker 5.

[0036] The latch 12 has an engagement groove 123 with which the first leg portion 51 of the striker 5 can engage, a first arm portion 121 that is on the latch direction side of the engagement groove 123 and extends in the centrifugal direction centered on the latch shaft 11, a second arm portion 122 that is on the unlatch direction side of the engagement groove 123 and extends in the centrifugal direction centered on the latch shaft 11, a third arm portion 124 provided between the engagement groove 123 and the second arm portion 122, a fourth arm portion 126 that is spaced apart from the first arm portion 121 by a predetermined distance in the latch direction, and a columnar pressed portion 127 provided on the side surface and protruding in the axial direction of the latch shaft 11.

[0037] The latch 12 is formed by making the core material metal and coating the surface except for the tip portions of the first and second arm portions 121 and 122 and the pressed portion 127 with a synthetic resin material.

[0038] The tip of the first arm portion 121 includes a first unlatch-side contact portion 121a that can engage with the first ratchet 9 in the unlatch direction at the first latch position of the latch 12, and a first latch-side contact portion 121b that can engage with the hook portion 101 (described later) of the second ratchet 10 in the latch direction at the first latch position of the latch 12. The tip of the second arm portion 122 includes a second unlatch-side contact portion 122a that can engage with the first ratchet 9 in the unlatch direction at the second latch position of the latch 12, and a second latch-side contact portion 122b that can engage with the hook portion 101 of the second ratchet 10 in the latch direction at the second latch position of the latch 12.

[0039] When the latch 12 is in the unlatch position, as shown in FIG. 6, the first arm portion 121 is in a posture that slopes obliquely upward to the rear and overlaps with the striker entry groove 71. When the latch 12 is in the second latch position, it assumes a forward posture, moves out of the striker entry groove 71, and moves downward below the striker entry groove 71.

[0040] When the latch 12 is in the unlatch position, the second arm portion 122 is located below the striker entry groove 71, moves upward as the latch 12 rotates in the latch direction, and moves above the striker entry groove 71 at the second latch position.

[0041] When the latch 12 is in the unlatch position, the third arm portion 124 is in a posture that slopes obliquely upward to the rear and is located below the striker entry groove 71. When the latch 12 rotates to the second latch position, it overlaps with the striker entry groove 71 and assumes a forward posture, and the tip portion 125 of itself faces the first contact portion 191a of the first auxiliary arm portion 191 of the meshing auxiliary lever 19.

[0042] When the latch 12 rotates to the second latch position, the first leg portion 51 of the striker 5 is clamped between the tip portion 125 of the third arm 124 and the first contact portion 191a of the meshing auxiliary lever 19.

[0043] The meshing groove 123 is provided between the first arm portion 121 and the third arm portion 124. When the latch 12 is in the unlatch position, it is in a position overlapping the striker entry groove 71. Along with the upright operation of the seat back 3B, the first leg portion 51 of the striker 5 enters the striker entry groove 71, thereby meshing with the first leg portion 51. Accordingly, the latch 12 rotates from the unlatch position in the latch direction to the first latch position shown in FIG. 10. Further, the first leg portion 51 of the striker 5 deeply enters the striker entry groove 71, and the first leg portion 51 of the striker 5 abuts against the first contact portion 191a of the first auxiliary arm portion 191 of the meshing auxiliary lever 19. By the meshing auxiliary lever 19 rotating from the standby position in the entry direction, the second auxiliary arm portion 192 abuts against the pressed portion 127 of the latch 12. Thereby, the latch 12 rotates to a position before the second latch position shown in FIG. 14 or to the second latch position shown in FIG. 15. In the present embodiment, the latch 12 rotates to a position before the second latch position when the second auxiliary arm portion 192 abuts against the pressed portion 127 of the latch 12, and is configured to rotate from the position before the second latch position to the second latch position by a cam portion 92 (described later) provided on the first ratchet 9.

[0044] The pressed portion 127 is cylindrical and is provided so as to protrude in the axial direction of the latch shaft 11 on the side surface of the third arm portion 124 of the latch 12. When the latch 12 is in the unlatch position, it is located below the striker entry groove 71, and when the latch 12 reaches a position before the first latch position, it moves to a position overlapping the striker entry groove 71.

[0045] The first ratchet 9 has an engaging portion 91 provided at the front end thereof and a cam portion 92 continuously provided below the engaging portion 91. As shown in FIG. 10, the engaging portion 91 engages with the first arm portion 121 at the first latch position of the latch 12 to prevent the latch 12 from rotating in the unlatch direction from the first latch position. As shown in FIG. 15, the engaging portion 91 engages with the second arm portion 122 at the second latch position of the latch 12 to prevent the latch 12 from rotating in the unlatch direction from the second latch position.

[0046] Furthermore, based on the operation of the operation member 6, the first ratchet 9 rotates in the release direction (clockwise) from the engaged position where the engaging portion 91 is engaged with the first arm portion 121 or the first arm portion 122, so that the engaging portion 91 disengages from the first arm portion 121 or the second arm portion 122, allowing the latch 12 to rotate in the unlatch direction.

[0047] In the following description, as shown in FIGS. 3, 4, and 6, the state where the lower edge of the first ratchet 9 rides on the outer peripheral portion 126a of the latch 12 is defined as the standby position of the first ratchet 9, and as shown in FIGS. 10 and 15, the state where the engaging portion 91 is engaged with the first arm portion 121 or the second arm portion 122 is defined as the engaged position of the first ratchet 9, and as shown in FIGS. 11 and 16, the state where the engaging portion 91 disengages from the first arm portion 121 or the second arm portion 122 is defined as the release operation of the first ratchet 9, respectively.

[0048] The cam portion 92 of the first ratchet 9 abuts against the first unlatch-side abutting portion 121a of the first arm portion 121 in front of the first latch position of the latch 12, and by the biasing force of the spring 13 acting on the first ratchet 9, a rotational force in the latch direction is applied to the latch 12 to forcibly rotate the latch 12 to the first position. Also, in front of the second latch position of the latch 12, by abutting against the second unlatch-side abutting portion 122a of the second arm portion 122, by the biasing force of the spring 13 acting on the first ratchet 9, a rotational force in the latch direction is applied to the latch 12 to forcibly rotate the latch 12 from in front of the second latch position to the second latch position.

[0049] The second ratchet 10 has a hook portion 101 that protrudes downward at the front end thereof and is located at a position spaced a predetermined distance in the latching direction from the engaging portion 91 of the first ratchet 9. As a result, a restraining portion 103 is formed between the hook portion 101 and the engaging portion 91 of the first ratchet 9, where the first arm portion 121 of the latch 12 engages at the first latch position of the latch 12, and the second arm portion 122 of the latch 12 engages at the second latch position of the latch 12. The restraining portion 103 is formed such that the opening width facing downward is the same as or slightly larger than the width of the tip portions of the first arm portion 121 and the second arm portion 122, and by the tip portions of the first arm portion 121 or the second arm portion 122 engaging respectively, the latch 12 is restrained at the first latch position or the second latch position by preventing the latch 12 from rotating in both the latching direction and the unlatching direction.

[0050] An indicator (not shown) that can visually observe the meshing state of the locking mechanism 4 is connected to the indicator connection portion 104 of the second ratchet 10. The indicator is provided on the seat back 3B.

[0051] When the latch 12 is in the unlatching position, the hook portion 101 abuts against the outer peripheral portion 126a of the fourth arm portion 126 of the latch 12. When the latch 12 rotates in the latching direction from the unlatching position, as shown in FIG. 9, the hook portion 101 abuts against the first arm portion 121 of the latch 12 to stop the latch 12 at the first latch position. At the same time, due to the biasing force of the spring 13, as shown in FIG. 10, it moves to a position where it completely engages with the first arm portion 121. Further, when the latch 12 rotates in the latching direction from the first latch position, as shown in FIG. 15, it moves to the same position as shown in FIG. 10 due to the biasing force of the spring 13. In this way, when the latch 12 is in the unlatching position and the first and second latch positions, the position of the hook portion 101 on the second ratchet 10 changes relative to each other, so that the indicator can reliably confirm the engagement state of the second ratchet 10 with respect to the latch 12.

[0052] Furthermore, when the second ratchet 10 rotates by a predetermined angle in the release direction based on the operation of the operation member 6, the hook portion 101 disengages from the first arm portion 121 or the second arm portion 122 of the latch 12, thereby permitting the latch 12 to rotate in the latching direction. However, when the latch 12 is in the second latch position, the tip portion 125 of the third arm portion 124 abuts against the first contact portion 191a of the first auxiliary arm portion 191 of the meshing auxiliary lever 19 stopped at the restraint position via the first leg portion 51 of the striker 5. Thus, the latch 12 does not substantially rotate in the latching direction.

[0053] In the following description, as shown in FIGS. 3, 4, and 6, the state in which the hook portion 101 of the second ratchet 10 rides on the outer peripheral portion 126a of the latch 12 is defined as the standby position of the second ratchet 10. As shown in FIGS. 10 and 15, the state in which the hook portion 101 is completely engaged with the first arm portion 121 or the second arm portion 122 is defined as the engagement position of the second ratchet 10. Also, as shown in FIGS. 11 and 16, the state in which the hook portion 101 disengages from the first arm portion 121 or the second arm portion 122 is defined as the release operation of the second ratchet 10, respectively.

[0054] Next, with reference to FIGS. 6 to 17, the operation of the vehicle seat lock device 1 according to the present embodiment will be described.

[0055] FIG. 6 shows the unlatched state of the lock mechanism 4, FIG. 7 shows the first state during the transition from the unlatched state to the first latched state of the lock mechanism 4, FIG. 8 shows the second state during the transition from the unlatched state to the first latched state of the lock mechanism 4, FIG. 9 shows the third state during the transition from the unlatched state to the first latched state of the lock mechanism 4, FIG. 10 shows the first latched state of the lock mechanism 4, FIG. 11 shows the release operation in the first latched state of the lock mechanism 4, FIG. 12 shows the fourth state during the transition from the first latched state to the second latched state of the lock mechanism 4, FIG. 13 shows the fifth state during the transition from the first latched state to the second latched state of the lock mechanism 4, FIG. 14 shows the sixth state during the transition from the first latched state to the second latched state of the lock mechanism 4, FIG. 15 shows the second latched state of the lock mechanism 4, FIG. 16 shows the release operation in the second latched state of the lock mechanism 4, and FIG. 17 is an operation explanatory diagram of each after the release operation of the lock mechanism 3.

[0056] (When the seat back 3B is moved from the reclined position to the first position) When the seat back 3B is in the reclined position, as shown in FIG. 6, the latch 12 is held at the unlatched position, and the first and second latches 9, 10 and the meshing auxiliary lever 19 are each held at the standby position.

[0057] When the seat back 3B is raised from the reclined position, the first leg portion 51 of the striker 5 enters the striker entry groove 71 and abuts against the first arm portion 121 of the latch 12. As a result, as shown in FIG. 7, the latch 12 rotates in the latch direction from the unlatched position against the biasing force of the spring 17. When the latch 12 rotates in the latch direction, the first leg portion 51 of the striker 5 meshes with the meshing groove 123 of the latch 12, and the tip of the first arm portion 121 of the latch 12 approaches the lower edge portion 94 of the first latch 9.

[0058] Furthermore, when the latch 12 rotates in the latching direction while the first leg portion 51 of the striker 5 remains engaged with the engagement groove 123, as shown in FIG. 8, the tip of the first arm portion 121 of the latch 12 contacts the lower edge portion 94 of the first ratchet 9. As a result, as the latch 12 rotates in the latching direction, the tip of the first arm portion 121 rotates while slidingly contacting the lower edge portion 94 of the first ratchet 9, holding the first ratchet 9 in the standby position. In this state, the second ratchet 10 is held in the standby position.

[0059] When the first leg portion 51 and the second leg portion 52 of the striker 5 enter the striker entry groove 71 of the base plate 7, even if the entry position of the striker 5 with respect to the striker entry groove 71 of the base plate 7 is displaced in the vertical direction from the reference position due to an attachment position error of the rear seat 2, play in the movable portion of the seat back 3B, etc., if the displacement is within a predetermined allowable range, the entry of the first leg portion 51 and the second leg portion 52 of the striker 5 into the striker entry groove 71 is allowed. Thereby, even if the mutual attachment position relationship between the lock mechanism 4 and the striker 5 is slightly displaced from each other in the vertical direction, the first leg portion 51 of the striker 5 can be surely engaged with the engagement groove 123 of the latch 12.

[0060] Furthermore, when the latch 12 rotates in the latching direction, as shown in FIG. 9, the hook portion 101 of the second ratchet 10 disengages from the outer peripheral portion 126a of the latch 12, and the tip of the first arm portion 121 of the latch 12 disengages from the lower edge portion 94 of the first ratchet 9. As a result, the first ratchet 9 and the second ratchet 10 become rotatable to their respective engagement positions by the biasing forces of their respective springs 13 and 15, and the first arm portion 121 of the latch 12 abuts against the hook portion 101. Thereby, the latch 12 stops at the first latch position, preventing further rotation in the latching direction.

[0061] When the latch 12 is stopped at the first latch position, as shown in FIG. 10, the first ratchet 9 rotates to the engaged position by the biasing force of the spring 13, and the second ratchet 10 rotates to the engaged position by the biasing force of the spring 15. As a result, the first arm portion 121 of the latch 12 engages with the restraint portion 103 formed by the first ratchet 9 and the second ratchet 10, thereby preventing the rotation of the latch 12 in the latch direction and the unlatch direction from the first latch position. Thereby, the latch 12 is restrained at the first latch position. Further, the striker 5 is restrained at the first position shown in FIG. 10.

[0062] In a state where the latch 12 is restrained at the first latch position and the striker 5 is restrained at the first position, as shown in FIG. 10, the meshing groove 123 overlaps with the striker entry groove 71 and faces directly upward in the orthogonal direction. Thus, even if there is a slight shift in the vertical direction between the mounting position relationships of the lock mechanism 4 and the striker 5 with respect to each other, since the first leg portion 51 of the striker 5 can move relative to the inside of the meshing groove 123 of the latch 12 in the vertical direction, the vertical shift can be absorbed, and the first leg portion 51 of the striker 5 can be reliably meshed with the meshing groove 123 of the latch 12. Further, the second leg portion 52 of the striker 5 slightly enters the striker entry groove 71.

[0063] Regarding the operation when the first ratchet 9 rotates to the engaged position in detail, before the first ratchet 9 reaches the engaged position, first, the cam portion 92 abuts against the first arm portion 121 of the latch 12, and by the rotational force of the first ratchet 9 in the engagement direction by the biasing force of the spring 13, the latch 12 is forcibly rotated toward the first latch position, so that the latch 12 is reliably rotated from before the first latch position to the first latch position. Thereafter, the engaging portion 91 of the first ratchet 9 engages with the first arm portion 121 of the latch 12. Thereby, the engaging portion 91 of the first ratchet 9 can be reliably engaged with the first arm portion 121 of the latch 12. Therefore, the latch 12 is reliably restrained at the first latch position, and the seat back 3B can be reliably held at the first position without rattling.

[0064] When a large negative load is applied to the seat back 3B from the rear toward the front while the seat back 3B is held in the first position, due to the engagement of the first arm portion 121 of the latch 12 with the cam portion 92, there is a possibility that the first latch 9 may be forcibly released in the release direction. However, even if this state occurs, the first arm portion 121 abuts against the stepped portion 105 provided on the second latch 10, preventing the latch 12 from rotating in the unlatch direction and reliably restraining the latch 12 in the first latch position.

[0065] (When moving the seat back 3B from the first position to the second position) When the seat back 3B is held in the first position, as shown in FIG. 10, the latch 12 is restrained in the first latch position, the striker 5 is restrained in the first position, the first latch 9 and the second latch 10 are each held in the engaged position, and the meshing auxiliary lever 19 is held in the standby position.

[0066] When the operating member 6 is released by the user, as shown in FIG. 11, the first latch 9 is released from the engaged position, and in conjunction with this, the second latch 10 is also released from the engaged position. As a result, the engaging portion 91 of the first latch 9 disengages from the first arm portion 121 of the latch 12, and the hook portion 101 of the second latch 10 disengages from the first arm portion 121 of the latch 12, enabling the latch 12 to rotate in the latch direction and the unlatch direction from the first latch position.

[0067] Next, while holding the operating member 6, push the seat back 3B backward. As a result, as shown in FIG. 12, the first leg portion 51 of the striker 5 engages with the engagement groove 123 and moves into the striker entry groove 71 toward the inner part, the latch 12 rotates in the latch direction from the first latch position, and the first leg portion 51 abuts against the first contact portion 191a of the first auxiliary arm portion 191 of the meshing auxiliary lever 19.

[0068] Furthermore, as the first leg portion 51 of the striker 5 moves in the entering direction, when the latch 12 rotates in the latching direction and the meshing assist lever 19 rotates in the entering direction, as shown in FIG. 13, the meshing groove 123 of the latch 12 assumes a posture facing obliquely upward in the front. At substantially the same time as the first leg portion 51 of the striker 5 exits from the meshing groove 123, the third arm portion 124 of the latch 12 overlaps the striker entry groove 71 in the forward posture. And as the meshing assist lever 19 rotates in the entering direction from the standby position, the second auxiliary arm portion 192 abuts against the pressed portion 127 of the latch 12 in the rotational direction. As a result, the latch 12 is rotated in the latching direction as the pressed portion 127 is pushed by the second auxiliary arm portion 192 of the meshing assist lever 19 along with the rotation of the meshing assist lever 19 in the entering direction.

[0069] Furthermore, when the first leg portion 51 of the striker 5 moves in the striker entry groove 71, as shown in FIG. 14, the first leg portion 51 completely exits from the meshing groove 123 of the latch 12, and the meshing assist lever 19 stops at the restraint position as the second contact portion 191b of the first auxiliary arm portion 191 abuts against the base plate 7.

[0070] When the meshing assist lever 19 rotates to the position shown in FIG. 14, the latch 12 rotates to before the second latching position. And when the latch 12 rotates to before the second latching position, the cam portion 92 of the first ratchet 9 abuts against the second unlatching side contact portion 122a of the second arm portion 122 of the latch 12. As a result, the latch 12 is forcibly rotated from before the second latching position to the second latching position by the biasing force of the spring 13 acting on the latch 12 by the first ratchet 9, and stops at the second latching position as the tip portion 125 of the third arm portion 124 abuts against the first leg portion 51 as shown in FIG. 15.

[0071] When the latch 12 rotates to the second latch position and stops, the first leg portion 51 completely disengages from the engagement groove 123 of the latch 12 and is clamped between the elastically deformable first contact portion 191a of the engagement auxiliary lever 19 and the tip portion 125 of the third arm portion 124 of the latch 12. Then, the second ratchet 10 rotates to the engaged position by the biasing force of the spring 15, and the first ratchet 9 rotates to the engaged position by the biasing force of the spring 13. As a result, the second arm portion 122 of the latch 12 engages with the restraint portion 103 formed by the first ratchet 9 and the second ratchet 10, thereby preventing the latch 12 from rotating in the unlatch direction and the latch direction. Thereby, the striker 5 is restrained at the second position shown in FIG. 15, and the seat back 3B is held at the second position.

[0072] Also, in a state where the latch 12 is restrained at the second latch position and the striker 5 is restrained at the second position, the first leg portion 51 of the striker 5 is located between the tip portion 125 of the third arm portion 124 of the latch 12 and the first contact portion 191a on the opposite side of the second contact portion 191b that abuts against the base plate 7, so that the first leg portion 51 is reliably restrained in the striker entry groove 71 without rattling. In addition, by making the portion including the first and second contact portions 191a and 191b elastically deformable, the first leg portion 51 of the striker 5 can be more reliably restrained.

[0073] When a large load is applied to the seat back 3B from the rear to the front in a state where the seat back 3B is held at the second position, there is a possibility that the first ratchet 9 may be forcibly released in the release direction due to the second arm portion 122 of the latch 12 engaging with the cam portion 92. However, even if this state occurs, the second arm portion 122 abuts against the stepped portion 105 provided on the second ratchet 10, thereby preventing the latch 12 from rotating in the unlatch direction and reliably restraining the latch 12 at the second latch position.

[0074] As described above, in this embodiment, since the striker 5 can be restrained at the first position and the second position by a single latch 12, compared with the prior art, the number of components can be reduced and the configuration can be simplified.

[0075] (When moving the seat back 3B from the second position (or the first position) to the reclined position) When the seat back 3B is held at the second position (or the first position), the vehicle seat locking device 1 is in the state shown in FIG. 15 (or FIG. 10). In this state, when the operation member 6 is operated, as shown in FIG. 16 (or FIG. 11), the first latch 9 and the second latch 10 are released, and the rotation of the latch 12 in the unlatch direction is permitted.

[0076] When the seat back 3B is moved forward from the second position, as shown in FIG. 17, due to the withdrawal movement of the first leg portion 51 and the second leg portion 52 of the striker 5 from the striker entry groove 71, the latch 12 rotates from the second latch position to the unlatch position, and the engagement assist lever 19 rotates to the standby position. Thereby, the seat back 3B can be moved from the second position (or the first position) to the reclined position. Further, when the seat back 3B is moved forward from the first upright position, although not shown, due to the withdrawal movement of the first leg portion 51 of the striker 5 from the striker entry groove 71, the latch 12 rotates from the first latch position to the unlatch position. Thereby, the seat back 3B can be moved from the first position to the reclined position.

[0077] As described above, one embodiment of the present invention has been described. However, within the scope not departing from the gist of the present invention, various modifications and changes can be made to the above embodiment as follows.

[0078] (a) Attach the lock mechanism 4 to the vehicle body side and provide the striker 5 on the seat back 3B side.

[0079] (b) The latch is formed by integrally forming the first latch 9 and the second latch 10.

[0080] (c) Provide an elastic member such as rubber at the tip of the first auxiliary arm portion 191 (the portion including the first contact portion 191a and the second contact portion 191b) of the meshing auxiliary lever 19. Alternatively, in order to facilitate elastic deformation of the tip, provide a hollow portion at the tip.

[0081] (d) The engaging rod of the striker 5 shall have a single rod-shaped leg portion that fits into the fitting groove 123 of the latch 12. Preferably, provide a flange portion at the tip of the rod-shaped leg portion, and in a state where the leg portion is fitted into the fitting groove 123 of the latch 12, the flange portion of the leg portion engages with the periphery of the fitting groove 123 in the latch 12 in the axial direction of the latch shaft 12.

[0082] (e) The meshing auxiliary lever 19 is configured to be divided into a first auxiliary lever and a second auxiliary lever. The first auxiliary lever is provided with a first auxiliary arm portion 191, and the second auxiliary lever is provided with a second auxiliary arm portion 192.

Explanation of Reference Numerals

[0083] 1 Vehicle seat lock device 2 Rear seat 3A Seat cushion 3B Seat back 31B Seat frame 32B Bolt 4 Lock mechanism 5 Striker 51 First leg portion 52 Second leg portion 6 Operating member 7 Base plate 71 Striker entry groove 8 Latch shaft 8a Flange portion 9 First latch 91 Engaging portion 92 Cam portion 93 Protrusion portion 94 Lower edge portion 10 Second latch 101 Hook portion 102 Arm portion 103 Restraining portion 104 Indicator connection portion 105 Step portion 11 Latch shaft 11a Flange portion 12 Latch 121 First arm portion 121a First unlatch side contact portion 121b First latch side contact portion 122 Second arm part 122a Second unlatch side contact part 122b Second latch side contact part 123 Engagement groove 124 Third arm part 125 Tip part 126 Fourth arm part 126a Outer peripheral part 127 Pressed part 13 Spring 14 Operating force transmission member 15 Spring 16 Support part 16a Flange part 17 Spring 18 Shaft 19 Engagement auxiliary lever 19a Upper part 191 First auxiliary arm part 191a First contact part 191b Second contact part 192 Second auxiliary arm part 20 Spring

Claims

1. A striker attached to either the vehicle body or the seat back, a base plate attached to the other of the vehicle body or the seat back and having a striker entry groove in which a leg portion provided on the striker can advance and retreat as the seat back operates, a latch rotatably supported on the base plate by a latch shaft so as to be rotatable by a predetermined angle from an unlatch position via a first latch position to a second latch position and vice versa, and having an engagement groove engageable with the leg portion that has entered the striker entry groove, a first arm portion provided on the latch direction side of the engagement groove, a second arm portion provided on the unlatch direction side of the engagement groove, and a third arm portion provided between the engagement groove and the second arm portion; and a ratchet rotatably supported on the base plate by a ratchet shaft so as to be rotatable by a predetermined angle and biased in the engagement direction by a spring, and having a restraint portion that can restrain the latch in the first latch position by engaging with the first arm portion and restrain the latch in the second latch position by engaging with the second arm portion. A first auxiliary arm portion rotatably supported on the base plate by a shaft so as to be rotatable by a predetermined angle and against which the leg portion that has entered the striker entry groove can abut; and an engagement auxiliary lever having a second auxiliary arm portion that rotates from a standby position toward a restraint position when the leg portion abuts against the first auxiliary arm portion and can abut against the latch in the latch direction by this rotation. The latch is rotatable from the unlatch position to the first latch position when the leg portion that has entered the striker entry groove engages with the engagement groove, and is rotatable toward the second latch position by the movement of the second auxiliary arm portion accompanying the rotation of the engagement auxiliary lever to the restraint position. The leg portion of the striker is characterized in that when the latch rotates to the second latch position, it exits from the engagement groove and is sandwiched between the engagement auxiliary lever and the tip of the third arm portion. A vehicle seat lock device.

2. The engagement auxiliary lever is characterized in that when the second auxiliary arm portion abuts against a pressed portion provided on the latch, the latch is rotated to a position before the second latch position. The vehicle seat lock device according to claim 1.

3. The meshing auxiliary lever is stopped at the restraint position when the first auxiliary arm portion abuts against the base plate. The vehicle seat lock device according to claim 1 or 2, characterized in that.

4. The vehicle seat lock device according to claim 3, characterized in that a portion of the first auxiliary arm portion of the meshing auxiliary lever that abuts against the leg portion of the striker and a portion that abuts against the base plate are made of synthetic resin or an elastic body.

5. The meshing groove of the latch is in a position overlapping the striker entry groove when the latch is in a position between the unlatch position and before the second latch position, and retracts to a position not overlapping the striker entry groove when the latch is in the second latch position. The vehicle seat lock device according to any one of claims 1 to 4, characterized in that.

6. The ratchet has a cam portion that forcibly rotates the latch from a position before the second latch position to the second latch position by abutting against the second arm portion of the latch by the biasing force of the spring. The vehicle seat lock device according to any one of claims 1 to 5, characterized in that.

7. The ratchet includes a first ratchet rotatably supported by the ratchet shaft at a predetermined angle, and a second ratchet rotatably supported by the ratchet shaft independently of the first ratchet at a predetermined angle. The first ratchet has an engaging portion that prevents the latch from rotating in the unlatch direction from the first latch position of the latch by engaging with the first arm portion, and prevents the latch from rotating in the unlatch direction from the second position of the latch by engaging with the second arm portion. The second ratchet has a hook portion that prevents the latch from rotating in the latching direction from the first latch position of the latch by engaging with the first arm portion. The vehicle seat lock device according to any one of claims 1 to 6, characterized in that.

8. The vehicle seat lock device according to claim 7, which quotes claim 6, characterized in that the cam portion of the ratchet is continuously formed on the engaging portion of the first ratchet.

9. The striker entry groove has an opening width that is at least twice or more the thickness of the leg portion of the striker. The vehicle seat lock device according to any one of claims 1 to 8, characterized in that.

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