The present invention relates to a vehicle seat with a walk-in mechanism, in particular, relates to a lock mechanism of a seat back.
There is a vehicle seat including, what is called, a walk-in mechanism. In addition to an operation for changing angle of a seat back, the walk-in mechanism enables to release a lock of the seat back to instantaneously make a seat back fall forward, for example, when an occupant moves to a back seat by opening a front side door in a two door typed coupe.
As a background art in this technical field, there is Japanese Patent Application Laid-Open No. 2008-296659 (PTL 1). PTL 1 discloses a mechanism that positions the position of the center of gravity of a lock plate below an axial center position of a turning shaft in a locking device of a vehicle seat back that retains the seat back at a seating posture position by turning the lock plate about the turning shaft and engaging the lock plate with a lock pin, for the purpose of providing a locking device of a vehicle seat back that ensures further reliably retaining a lock state of the seat back at a seating posture position.
PTL 1: Japanese Patent Application Laid-Open No. 2008-296659
In PTL 1, the position of the center of gravity of a whole lock plate is set so as to be positioned below an axial center of a turning shaft and in a vehicle rear side. Even in a case where a luggage loaded in a luggage compartment moves to an occupant compartment side by an inertia force when a sudden braking is applied or when a frontal collision of the vehicle occurs, this is advantageous in restricting the lock plate from turning in a lock releasing direction due to the impact when the luggage collides with a seat back. The position of the center of gravity of the lock plate positioned in the vehicle rear side with respect to the axial center of the turning shaft is advantageous in restricting the lock plate from turning even if the luggage in the luggage compartment collides with the seat back. That is, since the lock plate is configured to be positioned at a lock actuating position by upwardly turning about the turning shaft from a vehicle front side toward the vehicle rear side, increasing a weight of the lock plate in the vehicle rear side keeps the lock plate biased to the lock actuating position by its own weight. Accordingly, PTL 1 describes that the lock plate is less likely to turn in the lock releasing direction from vehicle rear side toward the vehicle front side, and therefore, it is advantageous in restricting an unintended turning of the lock plate.
However, the objective of PTL 1 is a restriction of lock plate turning against an impact from the rear side to the front side due to the impact of the luggage loaded in the luggage compartment caused by the frontal collision of the vehicle or the like, in the structure where the lock plate is configured to be positioned at the lock actuating position by upwardly turning about the turning shaft from the vehicle front side toward the vehicle rear side. Therefore, impacts from directions other than the vehicle rear side, such as an impact thrusting upward, for example, by a vehicle floor broken in a vehicle collision, are not discussed.
The present invention has been made in consideration of these problems, and it is one of its objectives to provide a vehicle seat with a walk-in mechanism including a lock mechanism of a seat back that ensures further reliably retaining a lock state against impacts from any directions.
One example of the present invention in order to solve the above-described problems is, a vehicle seat with a walk-in mechanism including a reclining unit that includes the walk-in mechanism. The reclining unit includes a swing plate and a latch for locking a seat back at a seating posture position. The latch has a structure that turns about a latch rotation shaft, locks the turning of the seat back by engaging with the swing plate, and releases the lock by disengaging from the swing plate. The latch has a structure in which a counter plate is added on an opposite side of a position where the latch engages with the swing plate with respect to the latch rotation shaft, and a position of a center of gravity of the latch is brought close to a rotational center of the latch.
With the present invention, a vehicle seat with a walk-in mechanism including a lock mechanism of a seat back that ensures further reliably retaining a lock state against impacts from any directions can be provided.
The following describes an example of the present invention with reference to the drawings.
First, a description will be given of a conventional vehicle seat with a walk-in mechanism as a prerequisite of the present invention.
Here, the center of gravity of the latch 7 is positioned at a position indicated by a black circle in the drawing. In some cases, for example, a collision from a vehicle collision floats the latch by an inertia force, and releases the lock.
Accordingly, this example is configured such that the position of the center of gravity of the latch is brought close to a rotational center of the latch in order to solve the above-described problems. The following describes the example with reference to the drawings.
Generated torque=latch weight×position of center of gravity from rotational center (1)
That is, it is a value obtained by multiplying a distance from the rotational center of the latch to the position of the center of gravity of the latch by the latch weight. In
That is, for all the direction including an impact in a vertical direction thrusting upward by a vehicle floor broken in a vehicle collision and an impact in a front-rear direction, a rotating torque generated in the latch by the inertia force can be reduced. Therefore, the lock state can be further reliably retained.
It should be noted that, while in
Integrating the counter plate 11 with the latch 7 ensures reducing the number of components. The counter plate 11 may be made of a material with a heavy specific gravity, such as lead, by considering an issue of a space. The torque generated by the inertia force is proportionate to the latch weight, and therefore, a hole may be made for a weight reduction after ensuring strength.
As described above, this example is configured such that the position of the center of gravity of the latch is brought close to the rotational center of the latch. This ensures providing the vehicle seat with the walk-in mechanism including the lock mechanism of the seat back that ensures reducing the torque of the latch by the inertia force generated due to a collision or the like so as to further reliably retain the lock state against the impacts from any directions.
While the example has been described above, the present invention is not limited to the above-described examples, and includes various modifications. The above-described examples are described in detail for simply describing the present invention, and do not necessarily include all the described configurations. A part of the configurations of the example can be replaced by the configuration of another example.
Number | Date | Country | Kind |
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2016-101806 | May 2016 | JP | national |
Filing Document | Filing Date | Country | Kind |
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PCT/JP2017/017084 | 4/28/2017 | WO | 00 |
Publishing Document | Publishing Date | Country | Kind |
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WO2017/199740 | 11/23/2017 | WO | A |
Number | Name | Date | Kind |
---|---|---|---|
3628831 | Close | Dec 1971 | A |
4518190 | Kluting | May 1985 | A |
5058240 | Barda | Oct 1991 | A |
5100202 | Hughes | Mar 1992 | A |
5370440 | Rogala | Dec 1994 | A |
Number | Date | Country |
---|---|---|
2524571 | Feb 1997 | JP |
2004-257104 | Sep 2004 | JP |
2008-296659 | Dec 2008 | JP |
2014-226994 | Dec 2014 | JP |
Entry |
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International Search Report from International Patent Application No. PCT/JP2017/017084, dated Jul. 18, 2017. |
Office Action dated Sep. 3, 2019 in Japanese Patent Application No. 2018-518204. |
Number | Date | Country | |
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20190070987 A1 | Mar 2019 | US |