JP7700993B2 - Vehicle seat lock device - Google Patents

Description

The present invention relates to a vehicle seat lock device, and in particular to a vehicle seat lock device that allows the seat back angle to be changed in two stages.

Conventionally, in vehicle seat lock devices, for example, in vehicle seats, there are those that allow the seat back's reclining angle to be changed between two positions, a first position and a second position, by engaging a locking mechanism provided on the seat back that is supported rotatably relative to the vehicle body with a striker fixed to the vehicle body.

For example, Patent Document 1 describes a striker that is fixed to the vehicle body and has a first rod-shaped engagement portion and a second rod-shaped engagement portion; a first hook plate that is rotatably supported by a first shaft on a base plate that is fixed to a seat back and has a first front abutment surface that abuts against a portion of the first rod-shaped engagement portion on the opposite side to the reclining direction of the seat back at a first position of the seat back and a second front abutment surface that abuts against a portion of the second rod-shaped engagement portion on the opposite side to the reclining direction of the seat back at a second position of the seat back; The vehicle seat lock device is disclosed, which includes a second hook plate having a first rear contact surface that contacts the portion of the first rod-shaped engagement part in the reclining direction of the seat back at the first position of the hook and a second rear contact surface that contacts the portion of the second rod-shaped engagement part in the reclining direction of the seat back at the second position of the seat back, a pole that is rotatably supported on the base plate by a second shaft and engages with the first hook plate to stop the rotation of the first hook plate, and a cam that rotates in conjunction with the pole, thereby allowing the seat back to be changed between two positions, a first position and a second position.

JP 2019-131100 A

However, the vehicle seat lock device disclosed in Patent Document 1 has a problem in that the number of parts is large and the structure is complex because the elements that mesh with the first and second rod-shaped engagement parts of the striker are composed of two parts, a first hook plate and a second hook plate, in order to change the reclining angle of the seat back to two levels, a first position and a second position.

In view of the above problems, the present invention aims to provide a vehicle seat lock device that has a simplified configuration and allows the seat back angle to be changed in two stages, a first position and a second position.

According to the present invention, the above problems are solved as follows.
a base plate attached to the other of the vehicle body or the seat back, the base plate having a striker entrance groove in which a leg portion of the striker can advance and retreat as the seat back is operated; a latch supported on the base plate by a latch shaft so as to be rotatable by a predetermined angle, the latch being rotatable from an unlatch position to a second latch position via a first latch position and vice versa, the latch having an engagement groove capable of engaging with the leg portion that has entered the striker entrance 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 latch supported on the base plate by a ratchet shaft so as to be rotatable by a predetermined angle, the latch being urged in an engagement direction by a spring to engage with the first arm portion, thereby restraining the latch in the first latch position, the latch is provided with a ratchet having a restraining portion capable of restraining the latch at a second latch position by engaging with the second arm portion; a first auxiliary arm portion supported on the base plate so as to be rotatable by a predetermined angle by a shaft, and against which the leg that has entered the striker entrance groove can abut; and an engagement auxiliary lever which rotates from a standby position to a restraining position when the leg abuts against the first auxiliary arm portion, and has a second auxiliary arm portion which abuts against the latch in a latching direction by this rotation, wherein the latch is rotatable from a standby position to a first latch position by the leg that has entered the striker entrance groove engaging with the engagement groove, and is rotatable toward the second latch position by movement of the second auxiliary arm portion accompanying the rotation of the engagement auxiliary lever to the restraining position, and the leg of the striker comes out of the engagement groove and is clamped between the engagement auxiliary lever and the tip end of the third arm portion when the latch rotates to the second latch position.

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

Preferably, the engagement auxiliary lever stops in the restraining position when the first auxiliary arm portion abuts against the base plate.

Preferably, the portion of the first auxiliary arm of the engagement auxiliary lever that abuts against the first leg of the striker and the portion that abuts against the base plate are made of synthetic resin or an elastic body.

Preferably, the engagement groove of the latch is in a position overlapping the striker entrance groove when the latch is in a position between the unlatched position and a position just before the second latched position, and retracts to a position not overlapping the striker entrance groove when the latch is in the second latched position.

Preferably, the ratchet has a cam portion that abuts against the second arm portion of the latch due to the biasing force of the spring, thereby forcibly rotating the latch from a position just before the second latch position to the second latch position.

Preferably, the ratchet includes a first ratchet supported by the ratchet shaft so as to be rotatable by a predetermined angle, and a second ratchet supported by the ratchet shaft so as to be rotatable by a predetermined angle independently of the first ratchet, the first ratchet has an engagement portion that engages with the first arm portion to prevent the latch from rotating in the unlatch direction from the first latch position and engages with the second arm portion to prevent the latch from rotating in the unlatch direction from the second position, and the second ratchet has a hook portion that engages with the first arm portion to prevent the latch from rotating in the latch direction from the first latch position.

Preferably, the cam portion of the ratchet is formed continuously with the engagement portion of the first ratchet.

Preferably, the striker entry groove has an opening width at least twice as large as the thickness of the leg of the striker.

According to the present invention, by making the element that engages with the striker a single latch, it is possible to reduce the number of parts and simplify the configuration while still allowing the seat back angle to be changed to two stages, a first position and a second position.

1 is a perspective view of a seat equipped with a vehicle seat lock device according to the present invention; FIG. FIG. FIG. 4 is a vertical cross-sectional view taken along line VV in FIG. 3. FIG. 13 is an explanatory diagram of an unlatched state of the lock mechanism. 11 is an explanatory diagram of an operation of the lock mechanism in a first state during the transition from an unlatched state to a first latched state. FIG. 13 is an explanatory diagram of an operation of the lock mechanism in a second state in the middle of the transition from an unlatched state to a first latched state. FIG. 13 is an explanatory diagram of an operation of the lock mechanism in a third state midway from the unlatched state to the first latched state. FIG. FIG. 11 is an explanatory diagram of a first latch state in the lock mechanism. 11A and 11B are explanatory diagrams of a release operation in the first latch state of the lock mechanism. 13 is an explanatory diagram of an operation of the lock mechanism in a fourth state in the middle of transitioning from the first latched state to the second latched state. FIG. 13 is an explanatory diagram of an operation of the lock mechanism in a fifth state in the middle of the transition from the first latched state to the second latched state. FIG. 13 is an explanatory diagram of an operation of the lock mechanism in a sixth state midway from the first latched state to the second latched state. FIG. FIG. 13 is an explanatory diagram of a second latch state in the lock mechanism. 13A and 13B are explanatory diagrams of a release operation in the second latch state of the lock mechanism. 13A and 13B are explanatory views of the operation of the lock mechanism after the release operation.

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

The vehicle seat lock device 1 has a lock mechanism 4 attached to the seat back 3B and a striker 5 fixed to the vehicle body. When the seat back 3B is in the upright position, the lock mechanism 4 engages with the striker 5, allowing the seat back angle of the seat back 3B to be changed between two positions: a first position shown by a solid line in FIG. 1, and a second position shown by a two-dot chain line that is tilted further rearward than the first position.

The seat back 3B is selectively held in either the first or second position as described above, and can be moved forward to a collapsed position as shown by the two-dot chain line in FIG. 1 by disengaging the locking mechanism 4 from the striker 5 based on the operation of the operating member 6 provided on the shoulder of the seat back 3B.

As can be seen from FIG. 1, the striker 5 has an engagement rod (no reference number) that is generally U-shaped in plan view and is fixed to the vehicle body side facing the side of the seat back 3. The engagement rod has a first leg 51 on the front side and a second leg 52 on the rear side that is spaced a predetermined distance rearward from the first leg 51.

As shown in Figures 2 to 5, the locking mechanism 4 includes a metal base plate 7 fixed to the seat frame 31B (see Figure 5) in the seat back 3B, a ratchet including a first ratchet 9 and a second ratchet 10 supported on the base plate 7 by a ratchet shaft 8 facing left and right so as to be rotatable at a predetermined angle, a latch 12 supported on the base plate 7 by a latch shaft 11 facing left and right so as to be rotatable at a predetermined angle, and an engagement auxiliary lever 19 supported on the base plate 7 by a shaft 18 facing left and right so as to be rotatable at a predetermined angle. As a result, by arranging the first and second ratchets 9, 10 and the engagement auxiliary lever 19 above the striker entrance groove 71 in the base plate 7 and arranging the latch 12 below the striker entrance groove 71 as described below, the dimensions of the locking mechanism 4, particularly in the front-rear direction, can be reduced, making it possible to make it more compact.

The base plate 7 is made of metal and has a striker entry groove 71 at approximately the center in the vertical direction that is open at the rear so that the first and second legs 51, 52 of the striker 5 can move forward and backward when the seat back 3B is operated.

The vertical opening width of the striker entry groove 71 of the base plate 7 is set to about 2 to 3 times the thickness (diameter) of the first leg 51 and the second leg 52 of the striker 5. As a result, even if the entry position of the striker 5 into the striker entry groove 71 of the base plate 7 is shifted vertically from the reference position due to an error in the mounting position of the rear seat 2, play in the movable part of the seat back 3B, etc., as long as the deviation in the movement trajectory of the first and second leg parts 51, 52 of the striker 5 is within a predetermined allowable range, as shown in Figures 6 to 17, the first and second leg parts 51, 52 of the striker 5 are allowed to enter the striker entry groove 71.

In Figures 6 to 17, the first and second legs 51, 52 shown by solid lines indicate the reference position, and the first and second legs 51a, 52a shown by two-dot chain lines (see Figure 6) indicate positions that are vertically displaced from the reference position due to an error in the mounting position of the rear seat 2, play in the movable part of the seat back 3B, etc. In addition, the path X shown by a dashed dot line (see Figure 6) indicates the reference approach trajectory of the first and second legs 51, 52 relative to the striker approach groove 71 of the base plate 7 in the reference position, and the paths X1, X2 shown by dashed dot lines (see Figure 6) indicate the approach trajectories of the first and second legs 51a, 52a relative to the striker approach groove 71 of the base plate 7 when a deviation has occurred.

The base plate 7 is fixed to the seat frame 31B by a cylindrical support part 16 with a flange fixed to the upper front part of the base plate 7 itself, and by a number of bolts 32B inserted into the first and second shaft parts 8 and 11, which have the same shape as the support part 16. In detail, as shown in FIG. 5, the support part 16 and the flange parts 16a, 8a, and 11a of the first and second shaft parts 8 and 11 are fixed to the seat frame 31B by the number of bolts 32B with the respective parts abutting against the surface of the seat frame 31B.

The first ratchet 9 is made of metal and is supported by the ratchet shaft 8 above the striker entry groove 71 in the base plate 7 so as to be rotatable by a predetermined angle, and is biased in the engagement direction (counterclockwise in FIG. 3, 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 that can move up and down. As a result, the first ratchet 9 rotates a predetermined angle around the ratchet shaft 8 in the release direction (clockwise in FIG. 3, counterclockwise in FIG. 4) against the biasing force of the spring 13 in conjunction with the operation of the operating member 6.

The second ratchet 10 is supported by the ratchet shaft 8 above the striker entry groove 71 on the base plate 7 so as to be rotatable a predetermined angle independently of the first ratchet 9, and is biased in the engagement direction (counterclockwise in FIG. 3, clockwise in FIG. 4) by a spring 15 supported by a support portion 16 on the base plate 7, and rotates in the release direction in conjunction with the rotation of the first ratchet 9 in the release direction. The rotation of the second ratchet 10 in the release direction in conjunction with the rotation of the first ratchet 9 in the release direction is achieved when the protrusion 93 on the first ratchet 9 abuts against the arm portion 102 on the second ratchet 10 from the release direction.

The engagement assist lever 19 is made of synthetic resin and is supported by a shaft 18 at the top of the back of the striker entry groove 71 in the base plate 7 so that it can rotate by a predetermined angle. It is also biased in the standby direction (e.g., counterclockwise in Figures 3 and 6, clockwise in Figure 4) by a spring 20 supported by the shaft 18, and is normally held in the standby position shown in Figures 3, 4, and 6, for example, with its upper part 19a abutting against the base plate 7.

Furthermore, the engagement auxiliary lever 19 has a first auxiliary arm portion 191 that extends downward in the standby position and a second auxiliary arm portion 192 that extends forward. As the first leg portion 51 of the striker 5 enters the striker entrance groove 71, the first leg portion 51 abuts against the first auxiliary arm portion 191, causing the engagement auxiliary lever 19 to rotate a predetermined angle in the entrance direction (e.g., clockwise in Figures 3 and 6, counterclockwise in Figure 4) against the biasing force of the spring 20 from the standby position and stop at the restraint position shown in Figure 15.

The first auxiliary arm portion 191 extends downward so as to overlap the striker entrance groove 71 in the left-right direction in the standby position, and has a first abutment portion 191a provided on the side opposite to the entrance direction of the first leg portion 51 of the striker 5, and a second abutment portion 191b provided on the opposite side of the first abutment portion 191a and opposite to a part of the base plate 7. As a result, the first leg portion 51 of the striker 5 enters the striker entrance groove 71, and the first leg portion 51 abuts against the first abutment portion 191a at a predetermined position, causing the engagement auxiliary lever 19 to rotate from the standby position to the restraining position. When the engagement auxiliary lever 19 rotates to the restraining position, the second abutment portion 191b abuts against the base plate 7, preventing the engagement auxiliary lever 19 from rotating further and stopping at the restraining position. Preferably, when the first leg 51 abuts against the first abutment portion 191a of the first auxiliary arm portion 191 and the second abutment portion 191b of the first auxiliary arm portion 191 abuts against the base plate 7, the first abutment portion 191a and the second abutment portion 191b are formed thick so that they can be slightly elastically deformed in the direction in which the striker 5 enters. This makes it possible to reduce the abutment sound when the first leg 51 of the striker 5 abuts against the first abutment portion 191a of the first auxiliary arm portion 191. Furthermore, it is also possible to reduce the abutment sound when the second abutment portion 191b of the first auxiliary arm portion 191 abuts against the base plate 7.

The second auxiliary arm portion 192 is located above the striker entry groove 71 when the engagement auxiliary lever 19 is in the standby position. When the engagement auxiliary lever 19 rotates from the standby position in the entry direction, the second auxiliary arm portion 192 abuts against and pushes a pressed portion 127 (described below) provided on the latch 12 at a predetermined position, thereby forcibly rotating the latch 12 in the latch direction.

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

When the seat back 3B is in a position other than the first and second positions and the striker 5 has not entered the striker entry groove 71 of the base plate 7, the latch 12 is stopped in the unlatched position shown in FIG. 6. When the striker 5 enters the striker entry groove 71 as the seat back 3B stands up, the latch 12 rotates from the unlatched position in the latch direction (counterclockwise in FIG. 6) against the biasing force of the spring 17 by a predetermined angle to the first latch position shown in FIG. 10 and stops at that position, and then rotates further from the first latch position in the latch direction by a predetermined angle to the second latch position shown in FIG. 15 and stops there. Also, the latch 12 rotates in the unlatched direction in the opposite direction as the seat back 3B is lowered based on the operation of the operating member 6.

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

The latch 12 has an engagement groove 123 with which the first leg 51 of the striker 5 can engage, a first arm portion 121 on the latch direction side of the engagement groove 123 and extending in a centrifugal direction centered on the latch shaft 11, a second arm portion 122 on the unlatch direction side of the engagement groove 123 and extending in a 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 spaced a predetermined distance from the first arm portion 121 in the latch direction, and a cylindrical pressed portion 127 provided on the side surface and protruding toward the axial direction of the latch shaft 11.

The latch 12 is formed by using a metal core and covering the surfaces, except for the tips of the first and second arm portions 121 and 122 and the pressed portion 127, with a synthetic resin material.

The tip of the first arm portion 121 includes a first unlatch side abutment portion 121a that can engage with the first ratchet 9 in the unlatch direction when the latch 12 is in the first latch position, and a first latch side abutment portion 121b that can engage with a hook portion 101 (described below) of the second ratchet 10 in the latch direction when the latch 12 is in the first latch position. The tip of the second arm portion 122 includes a second unlatch side abutment portion 122a that can engage with the first ratchet 9 in the unlatch direction when the latch 12 is in the second latch position, and a second latch side abutment portion 122b that can engage with the hook portion 101 of the second ratchet 10 in the latch direction when the latch 12 is in the second latch position.

When the latch 12 is in the unlatched position, the first arm portion 121 is in a position facing diagonally upward and rearward while overlapping the striker entry groove 71 as shown in FIG. 6, and when the latch 12 is in the second latched position, it is in a forward-facing position, disengages from the striker entry groove 71, and moves below the striker entry groove 71.

When the latch 12 is in the unlatched position, the second arm portion 122 is located below the striker entry groove 71, and moves upward as the latch 12 rotates in the latching direction, and moves above the striker entry groove 71 in the second latched position.

When the latch 12 is in the unlatched position, the third arm portion 124 is positioned below the striker entry groove 71 in a posture facing diagonally upward and rearward, and when the latch 12 rotates to the second latch position, it assumes a forward-facing posture overlapping the striker entry groove 71, with its own tip portion 125 facing the first abutment portion 191a of the first auxiliary arm portion 191 of the engagement auxiliary lever 19.

When the latch 12 rotates to the second latch position, the first leg 51 of the striker 5 is clamped between the tip 125 of the third arm 124 and the first abutment portion 191a of the engagement assist lever 19.

The meshing groove 123 is provided between the first arm portion 121 and the third arm portion 124, and is located so as to overlap with the striker entrance groove 71 when the latch 12 is in the unlatched position. When the seat back 3B is raised, the first leg portion 51 of the striker 5 enters the striker entrance groove 71, thereby meshing with the first leg portion 51. Accordingly, the latch 12 rotates from the unlatched position in the latch direction to the first latch position shown in FIG. 10, and further, the first leg portion 51 of the striker 5 deeply enters the striker entrance groove 71, and the first leg portion 51 of the striker 5 abuts against the first abutment portion 191a of the first auxiliary arm portion 191 of the meshing auxiliary lever 19. As a result, the meshing auxiliary lever 19 rotates from the standby position in the entrance direction, and the second auxiliary arm portion 192 abuts against the pressed portion 127 of the latch 12. As a result, the latch 12 rotates to a position just before the second latch position shown in Fig. 14 or to the second latch position shown in Fig. 15. In this embodiment, the latch 12 rotates to a position just 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 just before the second latch position to the second latch position by a cam portion 92 (described later) provided on the first ratchet 9.

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

The first ratchet 9 has an engagement portion 91 provided at its front end, and a cam portion 92 provided contiguous to the lower portion of the engagement portion 91. As shown in FIG. 10, the engagement portion 91 engages with the first arm portion 121 at the first latch position of the latch 12, thereby preventing the latch 12 from rotating in the unlatch direction from the first latch position, and as shown in FIG. 15, the engagement portion 91 engages with the second arm portion 122 at the second latch position of the latch 12, thereby preventing the latch 12 from rotating in the unlatch direction from the second latch position.

Furthermore, based on the operation of the operating member 6, the first ratchet 9 rotates in the release direction (clockwise) from the engagement position where the engagement portion 91 is engaged with the first arm portion 121 or the second arm portion 122, and the engagement portion 91 disengages from the first arm portion 121 or the second arm portion 122, allowing the latch 12 to rotate in the unlatching direction.

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

The cam portion 92 of the first ratchet 9 abuts against the first unlatch side abutment portion 121a of the first arm portion 121 just before the first latch position of the latch 12, and the biasing force of the spring 13 acting on the first ratchet 9 applies a rotational force in the latch direction to the latch 12, forcing the latch 12 to rotate to the first position. Also, just before the second latch position of the latch 12, the cam portion 92 abuts against the second unlatch side abutment portion 122a of the second arm portion 122, and the biasing force of the spring 13 acting on the first ratchet 9 applies a rotational force in the latch direction to the latch 12, forcing the latch 12 to rotate from just before the second latch position to the second latch position.

The second ratchet 10 has a hook portion 101 that protrudes downward at its front end and at a position spaced a predetermined distance from the engagement portion 91 of the first ratchet 9 in the latch direction. As a result, a restraining portion 103 is formed between the hook portion 101 and the engagement portion 91 of the first ratchet 9, with which the first arm portion 121 engages in the first latch position of the latch 12 and with which the second arm portion 122 engages in the second latch position of the latch 12. The restraining portion 103 is formed so that the opening width facing downward is the same as or slightly larger than the width of the tip of the first arm portion 121 and the second arm portion 122, and the tip of the first arm portion 121 or the second arm portion 122 engages with the restraining portion 103, respectively, thereby preventing the latch 12 from rotating in both the latch direction and the unlatch direction, thereby restraining the latch 12 in the first latch position or the second latch position.

An indicator (not shown) that allows the engagement state of the locking mechanism 4 to be visually observed is connected to the indicator connection portion 104 of the second ratchet 10. The indicator is provided on the seat back 3B.

When the latch 12 is in the unlatched position, the hook portion 101 abuts against the outer periphery 126a of the fourth arm portion 126 of the latch 12, and when the latch 12 rotates from the unlatched position in the latching direction, as shown in FIG. 9, the hook portion 101 abuts against the first arm portion 121 of the latch 12, stopping the latch 12 at the first latched position, and moves to a position where it fully engages with the first arm portion 121 as shown in FIG. 10 due to the biasing force of the spring 13, and when the latch 12 rotates from the first latched position in the latching direction, as shown in FIG. 15, the hook portion 101 of the second ratchet 10 changes position relative to the first and second latched positions, so that the indicator can reliably confirm the engagement state of the second ratchet 10 with the latch 12.

Furthermore, when the second ratchet 10 rotates a predetermined angle in the release direction based on the operation of the operating member 6, the hook portion 101 disengages from the first arm portion 121 or the second arm portion 122 of the latch 12, thereby allowing the latch 12 to rotate in the latch 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 abutment portion 191a of the first auxiliary arm portion 191 of the engagement auxiliary lever 19 stopped in the restraining position via the first leg portion 51 of the striker 5, so that the latch 12 does not actually rotate in the latch direction.

In the following description, the state in which the hook portion 101 of the second ratchet 10 rides up onto the outer periphery 126a of the latch 12 as shown in Figures 3, 4 and 6 is defined as the standby position of the second ratchet 10, the state in which the hook portion 101 is completely engaged with the first arm portion 121 or the second arm portion 122 as shown in Figures 10 and 15 is defined as the engagement position of the second ratchet 10, and the state in which the hook portion 101 is disengaged from the first arm portion 121 or the second arm portion 122 as shown in Figures 11 and 16 is defined as the release operation of the second ratchet 10.

Next, the operation of the vehicle seat lock device 1 according to this embodiment will be described with reference to Figures 6 to 17.

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

(When the seat back 3B is moved from the reclining 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 in the unlatched position, and the first and second ratchets 9, 10 and the engagement assist lever 19 are each held in the standby position.

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

Furthermore, when the latch 12 rotates in the latch direction while the first leg 51 of the striker 5 is engaged with the engagement groove 123, the tip of the first arm 121 of the latch 12 comes into contact with the lower edge 94 of the first ratchet 9, as shown in FIG. 8. As a result, as the latch 12 rotates in the latch direction, the tip of the first arm 121 rotates while sliding against the lower edge 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.

When the first leg 51 and the second leg 52 of the striker 5 enter the striker entrance groove 71 of the base plate 7, even if the entry position of the striker 7 relative to the striker entrance groove 71 of the base plate 7 is shifted in the vertical 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., the entry of the first leg 51 and the second leg 52 of the striker 5 into the striker entrance groove 71 is permitted as long as the shift is within a predetermined allowable range. As a result, even if the relative attachment positions of the locking mechanism 4 and the striker 5 are slightly shifted in the vertical direction, the first leg 51 of the striker 5 can be reliably engaged with the engagement groove 123 of the latch 12.

Furthermore, when the latch 12 rotates in the latch direction, as shown in FIG. 9, the hook portion 101 of the second ratchet 10 disengages from the outer periphery 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 due to the biasing forces of the respective springs 13, 15, and the first arm portion 121 of the latch 12 abuts against the hook portion 101. As a result, the latch 12 stops at the first latch position and is prevented from rotating further in the latch direction.

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 due to the biasing force of the spring 13, and the second ratchet 10 rotates to the engaged position due to the biasing force of the spring 15. As a result, the first arm portion 121 of the latch 12 engages with the restraining portion 103 formed by the first ratchet 9 and the second ratchet 10, preventing the latch 12 from rotating in the latch direction and the unlatch direction from the first latch position. As a result, the latch 12 is restrained at the first latch position. Also, the striker 5 is restrained at the first position shown in FIG. 10.

When the latch 12 is restrained in the first latch position and the striker 5 is restrained in the first position, as shown in FIG. 10, the engagement groove 123 overlaps with the striker entrance groove 71 and faces straight up in a direction perpendicular to the striker entrance groove 71. As a result, even if the relative mounting positions of the locking mechanism 4 and the striker 5 are slightly misaligned in the vertical direction, the first leg 51 of the striker 5 can move relatively in the vertical direction within the engagement groove 123 of the latch 12, so that the vertical misalignment can be absorbed and the first leg 51 of the striker 5 can be reliably engaged with the engagement groove 123 of the latch 12. In addition, the second leg 52 of the striker 5 slightly enters the striker entrance groove 71.

The operation of the first ratchet 9 when it rotates to the engagement position will be described in detail below. Before the first ratchet 9 reaches the engagement position, the cam portion 92 first abuts against the first arm portion 121 of the latch 12. The spring 13 biases the first ratchet 9 in the engagement direction, forcing the latch 12 to rotate toward the first latch position, thereby reliably rotating the latch 12 from just before the first latch position to the first latch position. After that, the engagement portion 91 of the first ratchet 9 engages with the first arm portion 121 of the latch 12. This ensures that the engagement 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 in the first latch position, and the seat back 3B can be reliably held in the first position without rattle.

When the seat back 3B is held in the first position and a large load is applied from the rear toward the front of the seat back 3B, the first arm portion 121 of the latch 12 is engaged with the cam portion 92, which may cause the first ratchet 9 to be forcibly released in the release direction. However, even if this occurs, the first arm portion 121 comes into contact with the step portion 105 on the second ratchet 10, preventing the latch 12 from rotating in the unlatching direction and reliably restraining the latch 12 in the first latch position.

(When the seat back 3B is moved 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 ratchet 9 and the second ratchet 10 are each held in the engaged position, and the engagement assist lever 19 is held in the standby position.

When the user releases the operating member 6, as shown in FIG. 11, the first ratchet 9 is released from the engaged position, and in conjunction with this, the second ratchet 10 is also released from the engaged position. As a result, the engagement portion 91 of the first ratchet 9 is disengaged from the first arm portion 121 of the latch 12, and the hook portion 101 of the second ratchet 10 is disengaged from the first arm portion 121 of the latch 12, allowing the latch 12 to rotate in the latch direction and the unlatch direction from the first latch position.

Next, while operating the operating member 6, the seat back 3B is pushed backward. As a result, as shown in FIG. 12, the first leg 51 of the striker 5 moves toward the back of the striker entrance groove 71 while engaged with the engagement groove 123, the latch 12 rotates in the latch direction from the first latch position, and the first leg 51 abuts against the first abutment portion 191a of the first auxiliary arm portion 191 of the engagement auxiliary lever 19.

Furthermore, as the first leg 51 moves in, the latch 12 rotates in the latch direction and the engagement auxiliary lever 19 rotates in the entry direction, as shown in FIG. 13, the engagement groove 123 of the latch 12 takes a position facing diagonally upward and forward, and at approximately the same time that the first leg 51 of the striker 5 comes out of the engagement groove 123, the third arm 124 of the latch 12 overlaps with the striker entry groove 71 in a forward position, and the engagement auxiliary lever 19 rotates from the standby position in the entry direction, so that the second auxiliary arm 192 abuts against the pressed portion 127 of the latch 12 in the rotation direction. As a result, the pressed portion 127 of the latch 12 is pressed by the second auxiliary arm 192 of the engagement auxiliary lever 19, and the latch 12 is rotated in the latch direction in conjunction with the rotation of the engagement auxiliary lever 19 in the entry direction.

Furthermore, when the first leg 51 of the striker 5 moves into the striker entrance groove 71, as shown in FIG. 14, the first leg 51 comes completely out of the engagement groove 123 of the latch 12, and the engagement auxiliary lever 19 stops in the restraining position as the second abutment portion 191b of the first auxiliary arm portion 191 abuts against the base plate 7.

When the engagement assist lever 19 rotates to the position shown in FIG. 14, the latch 12 rotates to just before the second latch position. Then, when the latch 12 rotates to just before the second latch position, the cam portion 92 of the first ratchet 9 abuts against the second unlatch side abutment portion 122a of the second arm portion 122 of the latch 12, and the latch 12 is forcibly rotated from just before the second latch position to the second latch position by the biasing force of the spring 13 acting on the first ratchet 9, and as shown in FIG. 15, the tip portion 125 of the third arm portion 124 abuts against the first leg portion 51, stopping at the second latch position.

When the latch 12 rotates to the second latch position and stops, the first leg 51 completely comes out of the meshing groove 123 of the latch 12 and is sandwiched between the elastically deformable first abutment portion 191a of the meshing assist lever 19 and the tip portion 125 of the third arm portion 124 of the latch 12. The second ratchet 10 then rotates to the engagement position due to the biasing force of the spring 15, and the first ratchet 9 rotates to the engagement position due to the biasing force of the spring 13. As a result, the second arm portion 122 of the latch 12 engages with the restraining 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. As a result, the striker 5 is restrained in the second position shown in FIG. 15, and the seat back 3B is held in the second position.

In addition, when the latch 12 is held in the second latch position and the striker 5 is held in the second position, the first leg 51 of the striker 5 is clamped between the tip 125 of the third arm portion 124 of the latch 12 and the first abutment portion 191a on the opposite side of the second abutment portion 191b that abuts against the base plate 7, so that the first leg 51 is securely held in the striker entry groove 71 without rattle. In addition, by making the portion including the first and second abutment portions 191a, 191b elastically deformable, the first leg 51 of the striker 5 can be more securely held.

When the seat back 3B is held in the second position and a large load is applied from the rear toward the front of the seat back 3B, the second arm portion 122 of the latch 12 is engaged with the cam portion 92, which may cause the first ratchet 9 to be forcibly released in the release direction. However, even if this occurs, the second arm portion 122 comes into contact with the step portion 105 on the second ratchet 10, preventing the latch 12 from rotating in the unlatching direction and reliably restraining the latch 12 in the second latch position.

As described above, in this embodiment, the striker 5 can be restrained in the first and second positions by a single latch 12, which allows for fewer components and a simpler configuration compared to conventional technology.

(When moving the seat back 3B from the second position (or the first position) to the folded position)
When the seat back 3B is held in the second position (or the first position), the vehicle seat lock device 1 is in the state shown in Fig. 15 (or Fig. 10). In this state, when the operating member 6 is operated, the first ratchet 9 and the second ratchet 10 are released as shown in Fig. 16 (or Fig. 11), allowing the latch 12 to rotate in the unlatching direction.

When the seat back 3B is moved forward from the second position, as shown in FIG. 17, the first leg 51 and the second leg 52 of the striker 5 move out of the striker entrance groove 71, causing the latch 12 to rotate from the second latch position to the unlatched position, and the engagement assist lever 19 to rotate to the standby position. This allows the seat back 3B to be moved from the second position (or the first position) to the reclined position. Also, when the seat back 3B is moved forward from the first upright position, although not shown in the figure, the first leg 51 of the striker 5 moves out of the striker entrance groove 71, causing the latch 12 to rotate from the first latch position to the unlatched position. This allows the seat back 3B to be moved from the first position to the reclined position.

Although one embodiment of the present invention has been described above, various modifications and changes can be made to the above embodiment without departing from the spirit of the present invention, as follows:

(a) The locking mechanism 4 is attached to the vehicle body, and the striker 5 is provided on the seat back 3B side.

(b) The ratchet is formed integrally with the first ratchet 9 and the second ratchet 10.

(c) An elastic member such as rubber is provided at the tip (the portion including the first contact portion 191a and the second contact portion 191b) of the first auxiliary arm portion 191 of the engagement auxiliary lever 19. Alternatively, a hollow portion is provided at the tip to facilitate elastic deformation of the tip.

(d) The engagement rod of the striker 5 has one rod-shaped leg that fits into the engagement groove 123 of the latch 12. Preferably, a flange is provided at the tip of the rod-shaped leg, and when the leg is fitted into the engagement groove 123 of the latch 12, the flange of the leg engages with the periphery of the engagement groove 123 of the latch 12 in the axial direction of the latch shaft 12.

(e) The engagement auxiliary lever 19 is divided into a first auxiliary lever and a second auxiliary lever, with a first auxiliary arm portion 191 provided on the first auxiliary lever and a second auxiliary arm portion 192 provided on the second auxiliary lever.

REFERENCE SIGNS LIST 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 52 Second leg 6 Operation member 7 Base plate 71 Striker entry groove 8 Ratchet shaft 8a Flange 9 First ratchet 91 Engagement portion 92 Cam portion 93 Projection 94 Lower edge 10 Second ratchet 101 Hook portion 102 Arm portion 103 Restraint portion 104 Indicator connection portion 105 Step portion 11 Latch shaft 11a Flange 12 Latch 121 First arm portion 121a First unlatch side abutment portion 121b First latch side abutment portion 122 Second arm portion 122a Second unlatch side abutment portion 122b Second latch side abutment portion 123 Interlocking groove 124 Third arm portion 125 Tip portion 126 Fourth arm portion 126a Outer periphery portion 127 Pressed portion 13 Spring 14 Operation force transmission member 15 Spring 16 Support portion 16a Flange portion 17 Spring 18 Shaft 19 Interlocking auxiliary lever 19a Upper portion 191 First auxiliary arm portion 191a First contact portion 191b Second contact portion 192 Second auxiliary arm portion 20 Spring

Claims (9)

A striker attached to either the vehicle body or the seat back;
a base plate attached to either the vehicle body or the seat back, the base plate having a striker entrance groove in which a leg portion of the striker can advance and retreat in accordance with operation of the seat back; a latch supported on the base plate by a latch shaft to be rotatable by a predetermined angle, the latch being rotatable from an unlatch position to a second latch position via a first latch position and vice versa, the latch having an interlocking groove capable of engaging with the leg portion that has entered the striker entrance groove, a first arm portion provided on a latch direction side of the interlocking groove, a second arm portion provided on an unlatch direction side of the interlocking groove, and a third arm portion provided between the interlocking groove and the second arm portion; and a ratchet supported on the base plate by a ratchet shaft to be rotatable by a predetermined angle, the ratchet being urged in an engagement direction by a spring, the ratchet having a restraining portion capable of engaging with the first arm portion to restrain the latch to the first latch position and engaging with the second arm portion to restrain the latch to the second latch position.
an engagement auxiliary lever including a first auxiliary arm portion supported on the base plate by a shaft so as to be rotatable by a predetermined angle, with which the leg portion that has entered the striker entrance groove can abut, and a second auxiliary arm portion that rotates from a standby position to a restraining position when the leg portion abuts against the first auxiliary arm portion and that can abut against the latch in a latch direction due to the rotation,
the latch is rotatable from an unlatched position to a first latched position by the leg portion that enters the striker entrance groove engaging with the engagement groove, and is rotatable toward a second latched position by movement of the second auxiliary arm portion accompanying the rotation of the engagement auxiliary lever to a restraining position, and the leg portion of the striker comes out of the engagement groove and is clamped between the engagement auxiliary lever and the tip end of the third arm portion by the rotation of the latch to the second latch position. The vehicle seat lock device according to claim 1, characterized in that the engagement auxiliary lever rotates the latch to just before the second latch position when the second auxiliary arm portion abuts against a pressed portion provided on the latch. The vehicle seat lock device according to claim 1 or 2, characterized in that the engagement auxiliary lever stops in the restraining position when the first auxiliary arm portion abuts against the base plate. 4. The vehicle seat lock device according to claim 3, wherein a portion of the first auxiliary arm portion of the engagement 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 elastic material. A vehicle seat lock device according to any one of claims 1 to 4, characterized in that the engagement groove of the latch is in a position overlapping the striker entrance groove when the latch is in a position between the unlatched position and a position just before the second latched position, and retracts to a position not overlapping the striker entrance groove when the latch is in the second latched position. The vehicle seat lock device according to any one of claims 1 to 5, characterized in that the ratchet has a cam portion that forcibly rotates the latch from a position just before the second latch position to the second latch position by contacting the second arm portion of the latch with the biasing force of the spring. The vehicle seat lock device according to any one of claims 1 to 6, characterized in that the ratchet includes a first ratchet supported by the ratchet shaft so as to be rotatable by a predetermined angle, and a second ratchet supported by the ratchet shaft so as to be rotatable by a predetermined angle independently of the first ratchet, the first ratchet has an engagement portion that engages with the first arm portion to prevent the latch from rotating in the unlatch direction from the first latch position and engages with the second arm portion to prevent the latch from rotating in the unlatch direction from the second position, and the second ratchet has a hook portion that engages with the first arm portion to prevent the latch from rotating in the latch direction from the first latch position. The vehicle seat lock device according to claim 7, which cites claim 6, characterized in that the cam portion of the ratchet is formed continuously with the engagement portion of the first ratchet. A vehicle seat lock device according to any one of claims 1 to 8, characterized in that the striker entry groove has an opening width at least twice as large as the thickness of the leg of the striker.

Images