US20100244530A1 - Seat reclining apparatus - Google Patents
Seat reclining apparatus Download PDFInfo
- Publication number
- US20100244530A1 US20100244530A1 US12/730,356 US73035610A US2010244530A1 US 20100244530 A1 US20100244530 A1 US 20100244530A1 US 73035610 A US73035610 A US 73035610A US 2010244530 A1 US2010244530 A1 US 2010244530A1
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- United States
- Prior art keywords
- frame
- internal gear
- tilt
- external gear
- gear
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
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Classifications
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60N—SEATS SPECIALLY ADAPTED FOR VEHICLES; VEHICLE PASSENGER ACCOMMODATION NOT OTHERWISE PROVIDED FOR
- B60N2/00—Seats specially adapted for vehicles; Arrangement or mounting of seats in vehicles
- B60N2/02—Seats specially adapted for vehicles; Arrangement or mounting of seats in vehicles the seat or part thereof being movable, e.g. adjustable
- B60N2/22—Seats specially adapted for vehicles; Arrangement or mounting of seats in vehicles the seat or part thereof being movable, e.g. adjustable the back-rest being adjustable
- B60N2/225—Seats specially adapted for vehicles; Arrangement or mounting of seats in vehicles the seat or part thereof being movable, e.g. adjustable the back-rest being adjustable by cycloidal or planetary mechanisms
- B60N2/2252—Seats specially adapted for vehicles; Arrangement or mounting of seats in vehicles the seat or part thereof being movable, e.g. adjustable the back-rest being adjustable by cycloidal or planetary mechanisms in which the central axis of the gearing lies inside the periphery of an orbital gear, e.g. one gear without sun gear
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60N—SEATS SPECIALLY ADAPTED FOR VEHICLES; VEHICLE PASSENGER ACCOMMODATION NOT OTHERWISE PROVIDED FOR
- B60N2/00—Seats specially adapted for vehicles; Arrangement or mounting of seats in vehicles
- B60N2/02—Seats specially adapted for vehicles; Arrangement or mounting of seats in vehicles the seat or part thereof being movable, e.g. adjustable
- B60N2/20—Seats specially adapted for vehicles; Arrangement or mounting of seats in vehicles the seat or part thereof being movable, e.g. adjustable the back-rest being tiltable, e.g. to permit easy access
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60N—SEATS SPECIALLY ADAPTED FOR VEHICLES; VEHICLE PASSENGER ACCOMMODATION NOT OTHERWISE PROVIDED FOR
- B60N2/00—Seats specially adapted for vehicles; Arrangement or mounting of seats in vehicles
- B60N2/02—Seats specially adapted for vehicles; Arrangement or mounting of seats in vehicles the seat or part thereof being movable, e.g. adjustable
- B60N2/20—Seats specially adapted for vehicles; Arrangement or mounting of seats in vehicles the seat or part thereof being movable, e.g. adjustable the back-rest being tiltable, e.g. to permit easy access
- B60N2/206—Seats specially adapted for vehicles; Arrangement or mounting of seats in vehicles the seat or part thereof being movable, e.g. adjustable the back-rest being tiltable, e.g. to permit easy access to a position in which it can be used as a support for objects, e.g. as a tray
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60N—SEATS SPECIALLY ADAPTED FOR VEHICLES; VEHICLE PASSENGER ACCOMMODATION NOT OTHERWISE PROVIDED FOR
- B60N2/00—Seats specially adapted for vehicles; Arrangement or mounting of seats in vehicles
- B60N2/02—Seats specially adapted for vehicles; Arrangement or mounting of seats in vehicles the seat or part thereof being movable, e.g. adjustable
- B60N2/22—Seats specially adapted for vehicles; Arrangement or mounting of seats in vehicles the seat or part thereof being movable, e.g. adjustable the back-rest being adjustable
- B60N2/235—Seats specially adapted for vehicles; Arrangement or mounting of seats in vehicles the seat or part thereof being movable, e.g. adjustable the back-rest being adjustable by gear-pawl type mechanisms
- B60N2/2352—Seats specially adapted for vehicles; Arrangement or mounting of seats in vehicles the seat or part thereof being movable, e.g. adjustable the back-rest being adjustable by gear-pawl type mechanisms with external pawls
Definitions
- This disclosure relates to a seat reclining apparatus.
- a known seat reclining apparatus includes a mechanism for adjusting a tilt angle of a seat back relative to a seat base by means of a driving force of an actuator and a stopper structure for determining a tilt limit of the seat back when a locked state between the seat back and the seat base is released.
- Such seat reclining apparatus is disclosed in JP61-48311A (hereinafter referred to as Reference 1).
- a reclining apparatus disclosed in Reference 1 includes a base provided at a seat cushion, an arm provided at a seat back so as to be rotatably connected to each other, and a sub plate arranged at a position where the sub plate is sandwiched between the base and the arm.
- the reclining apparatus further includes a lock mechanism of a planetary gear type between the sub plate and the arm. A sun gear included in the lock mechanism is manually operated so as to achieve a stepless reclining adjustment of the seat back relative to the seat base.
- a sub plate holding member is provided to obtain a locked state where the sub plate is connected to the base as a unit and an unlocked state where the sub plate is disconnected from the base.
- the sub plate holding member is rotated in a predetermined direction by a manual operation to thereby release an engagement of an engagement projection of the sub plate holding member with the sub plate, the sub plate is disconnected from the base.
- a locked state of the arm which is connected to the sub plate by the lock mechanism, relative to the base is released.
- the seat back is tiltable forward.
- the sub plate holding member is rotated in a direction opposite from the aforementioned predetermined direction so that the engagement projection of the sub plate holding member engages with the sub plate.
- the sub plate in addition to the arm, is locked at an original tilt position relative to the base.
- the seat reclining apparatus disclosed in Reference 2 includes lower arms attached to respective side portions of a seat cushion via lower brackets and upper arms attached to respective side portions of the seat back.
- Each of the lower arms is formed by an annular internal gear portion.
- Each of the upper arms is formed by an external gear portion that projects from a general flat portion of the upper arm attached to the seat back.
- the external gear portion of the upper arm has one fewer tooth or less compared to the internal gear portion of the lower arm.
- the external gear portion of the upper arm partially engages with the internal gear portion of the lower arm.
- the seat reclining apparatus disclosed in Reference 2 further includes a pair of wedges and the like by means of which the driving force of the drive mechanism is transmitted to the external gear portion of the upper arm. Then, the external gear portion rotates about an axial center eccentric to a center of a drive shaft. As a result, a meshed position of the external gear portion with the internal gear portion moves sequentially along an inner periphery of the internal gear portion to thereby adjust an angle of the upper arm relative to the lower bracket.
- the speed reduction of the driving force of the drive mechanism is achieved by the rotation of the external gear portion about a position eccentric to the center of the drive shaft, thereby specifying a position of the seat back.
- the meshed position between the external gear portion and the internal gear portion moves in the circumferential direction by the driving of the drive mechanism (i.e., the actuator)
- a portion of the internal gear portion with which the external gear portion is meshed is displaced away from the center of the drive shaft.
- the seat reclining apparatus disclosed in Reference 2 in a case where the seat back is tilted forward so as to achieve a walk-in function in the same way as the apparatus disclosed in Reference 1, a certain structure is required for supporting a reclining operation mechanism including the actuator, the external gear portion, the internal gear portion and the seat back to be rotatable about an axial center relative to the seat cushion. Then, the entire reclining operation mechanism is tilted forward by a release of a locked state between the seat back and the seat cushion in a case where the seat back is tilted forward.
- a stopper is required to determine a forward tilt limit.
- a structure where a frame of the seat back makes contact with the stopper provided at the seat cushion is considerable to use.
- a contact position of the frame of the seat back with the stopper may vary, which fails to maintain the forward tilt limit at a target forward tilt angle.
- the aforementioned reclining operation mechanism may often include a spring for biasing the seat back in the forward tilt direction.
- a spring for biasing the seat back in the forward tilt direction.
- a seat reclining apparatus includes a support frame tiltable about a support axis relative to a first frame constituting a seat cushion, an angle adjustment unit causing a second frame constituting a seat back to tiltably move forward or rearward relative to the support frame by a driving force of an actuator, the second frame being displaced in a direction to approach and separate from the support axis in a case where the second frame tiltably moves forward or rearward relative to the support frame, a lock mechanism selectively operated to an unlocked state where the support frame is allowed to integrally tiltably move with the angle adjustment unit about the support axis and a locked state where the support frame is prohibited to integrally tiltably move with the angle adjustment unit, and a front stopper provided at the first frame to specify a forward tilt limit of the seat back by making contact with a forward tilt contact portion provided at the second frame in a state where the lock mechanism is in the unlocked state, the front stopper including a linearly-shaped contact surface that makes contact with the forward tilt contact portion and that matches
- FIG. 1 is a side view illustrating a first frame and a second frame of a seat according to an embodiment disclosed here;
- FIG. 2 is a plan view illustrating a structure of the first frame
- FIG. 3 is a cross-sectional view taken along line III-III in FIG. 2 ;
- FIG. 4 is a cross-sectional view taken along the line IV-IV in FIG. 2 ;
- FIG. 5 is a cross-sectional view illustrating an angle adjustment unit according to the embodiment disclosed here;
- FIGS. 6A and 6B are cross-sectional views each illustrating a meshed state between an internal gear and an external gear according to the embodiment disclosed here;
- FIG. 7 is a side view illustrating a lock mechanism in a locked state according to the embodiment disclosed here;
- FIG. 8A is a side view illustrating a state where a front stopper and a forward tilt contact portion make contact with each other and
- FIG. 8B is a side view illustrating a state where a back stopper and a rearward tilt contact portion make contact with each other according to the embodiment disclosed here;
- FIG. 9 is an exploded perspective view illustrating a structure of the right angle adjustment unit.
- FIG. 10 is an exploded perspective view illustrating a structure of the left angle adjustment unit.
- a reclining-type seat for a vehicle such as a passenger car includes a seat cushion A of which a center portion in a width direction of the vehicle is formed by a seated surface and a seat back B attached at a rear edge of the seat cushion A so as to be tiltable in a longitudinal direction of the vehicle.
- directions and orientations such as left, right, front, rear, top, and bottom correspond to those when viewed from a passenger seated on the seat for a vehicle.
- the seat cushion A includes two first frames (i.e., left and right first frames) 1 constituting left and right side portions of the seat cushion A.
- the seat back B includes two second frames (i.e., left and right second frames) 2 constituting left and right side portions of the seat back B.
- the first frames 1 and the second frames 2 are tiltably connected to each other at left and right sides of the seat, respectively, about a support axis X.
- the seat also includes two angle adjustment units (i.e., left and right angle adjustment units) C at connecting portions between the first frames 1 and the second frames 2 respectively so as to arbitrarily specify a tilt amount (i.e., a tilt angle) of the second frames 2 relative to the first frames 1 by means of a driving force of a single actuator.
- the seat includes two lock mechanisms (i.e., left and right lock mechanisms) L that achieve a locked state where each of the second frames 2 is maintained at a fixed tilt angle relative to each of the first frames 1 and an unlocked state where each of the second frames 2 is tiltable relative to each of the first frames 1 .
- a seat reclining apparatus according to the present embodiment is constituted by a structure where the seat is tiltable by the first frames 1 and the second frames 2 , the angle adjustment units C, and the lock mechanisms L.
- each of the angle adjustment units C includes an upper gear plate 12 serving as a tilt frame, a lower gear plate 13 serving as a support frame, a fixed plate 14 and a lock release arm 15 that are arranged in this order along an axial center X (which is equal to the support axis X) of each drive shaft 11 (i.e., each of left and right drive shafts) rotatably supported by the first frame 1 .
- the lock release arm 15 is provided at only one of the angle adjustment units C (for example, at the right angle adjustment unit C).
- Inner ends of the left and right drive shafts 11 are connected to an intermediate shaft 16 .
- An outer end of one of the drive shafts 11 is provided with a first power transmission mechanism where a gear reduction mechanism 17 performs a speed reduction on a driving force of an electric motor M serving as the actuator and performs a power transmission of the resulting driving force.
- Left and right torsion springs 18 are provided at facing portions of the left and right first frames 1 .
- One end of each of the torsion springs 18 engages with a support block 1 A of the first frame 1 while the other end of each of the torsion springs 18 engages with the upper gear plate 12 .
- the second frames 2 are biased forward.
- each of the lower gear plates 13 includes multiple lock recess portions 13 A at a lower side.
- Each lock arm (i.e., each of left and right lock arms) 19 including multiple protruding portions 19 A engageable and disengageable relative to the multiple lock recess portions 13 A is supported at a side surface of each of the left and right first frames 1 so as to be rotatable about a lock support shaft 20 .
- the lock arm 19 includes a guide portion 19 B having a cutout shape along which a control roller 22 is movable.
- Each of the aforementioned lock mechanisms L is obtained by engagement and disengagement between the lock arm 19 and the lower gear plate 13 .
- the lock release arm 15 is movably supported about the support axis X at an outer wall portion of one of the fixed plates 14 , specifically, the right fixed plate 14 . Then, a linking arm 35 is provided at a position facing the lock release arm 15 across the right first frame 1 . The linking arm 35 is movable about the support axis X. The right control roller 22 is supported at both ends by the lock release arm 15 and the right linking arm 35 .
- An arm portion 15 A of the lock release arm 15 is provided with a grip of which a user takes hold.
- An operation arm 36 is movably supported about the support axis X at an outer wall portion of the other of the fixed plates 14 , specifically, the left fixed plate 14 .
- the operation arm 36 is provided at a position symmetrical to a position where the lock release arm 15 is provided.
- the left control roller 22 is supported at both ends by the operation arm 36 and the left linking arm 35 .
- the left and right linking arms 35 are connected to a linking shaft 23 within which the intermediate shaft 16 is coaxially fitted.
- the left linking arm 35 and the operation arm 36 receive a biasing force from a lock spring 21 (see FIG. 7 ) to thereby maintain the control roller 22 at a locked position.
- the guide portion 19 B of each of the lock arms 19 includes a lock area and an unlock area continuously formed as illustrated in FIGS. 7 , 8 A and 8 B.
- the protruding portions 19 A engage with the respective lock recess portions 13 A.
- the protruding portions 19 A of the lock arm 19 disengage from the respective lock recess portions 13 A.
- Each of the lock mechanisms L is brought to the unlocked state so that the seat back B is tilted forward by the biasing force of the left and right torsion springs 18 .
- the seat back B is tilted rearward against the biasing force of the left and right torsion springs 18 .
- the angle adjustment unit C transmits the driving force of the electric motor M from the gear reduction mechanism 17 to a second power transmission mechanism serving as a power transmission mechanism provided between the upper gear plate 12 and the lower gear plate 13 . Then, the speed reduction is conducted on the driving force by the second power transmission mechanism to thereby tilt the upper gear plate 12 relative to the lower gear plate 13 .
- each of the lower gear plates 13 is formed by a circular-shaped gear accommodating portion at a center.
- the gear accommodating portion is formed by press working, or the like, and is dent in a thickness direction of the lower gear plate 13 .
- a support boss portion 13 B is formed at a center of the gear accommodating portion by burring, or the like so as to protrude along the support axis X.
- a bore 13 H is formed at an inner periphery of the support boss portion 13 B.
- an internally toothed gear (internal gear) 13 G is integrally formed at an inner periphery of the gear accommodating portion of the lower gear plate 13 so as to be coaxial with the support boss portion 13 B.
- Each of the upper gear plates 12 is formed by a circular-shaped bulged portion at a center.
- the bulged portion is formed by a press working, or the like, and is dent in a thickness direction of the upper gear plate 12 .
- a circular-shaped bore 12 H penetrates through a center of the bulged portion.
- an externally toothed gear (external gear) 12 G is integrally formed at an outer periphery of the bulged portion of the upper gear plate 12 so as to be coaxial with the bore 12 H.
- the external gear 12 G has one fewer tooth or less compared to the internal gear 13 G.
- a pair of wedge pieces 25 is arranged at an outer periphery of the support boss portion 13 B so as to be slidable on the outer periphery thereof in a circumferential direction.
- the wedge pieces 25 are examples of eccentric members.
- Each of the wedge pieces 25 is integrally formed by a projecting portion 25 A along the support axis X.
- a loop-shaped spring 26 is disposed to bias the pair of wedge pieces 25 to separate them each other in the circumferential direction of the support boss portion 13 B.
- a cam plate 27 including an engagement recess portion 27 A that makes contact with the projecting portions 25 A of the pair of wedge pieces 25 so as to apply a rotational force thereto is provided at each of the drive shafts 11 .
- the pair of wedge pieces 25 collectively forms an outer peripheral shape that partially constitutes a periphery eccentric to the axial center X of each of the drive shafts 11 when viewed in a direction along the axial center X.
- the pair of wedge pieces 25 is arranged to make contact with an inner periphery of the bore 12 H of each of the upper gear plates 12 .
- a center of the external gear 12 G formed at each of the upper gear plates 12 is positioned eccentric to the axial center X of the drive shaft 11 . Consequently, a portion of the internal gear 13 G of each of the lower gear plates 13 is meshed with a portion of the external gear 12 G of each of the upper gear plates 12 .
- the center of the external gear 12 G of the upper gear plate 12 moves along a circumferential locus so as to be away from the axial center X of the drive shaft 11 . While the center of the external gear 12 G is moving, the meshed position between the external gear 12 G and the internal gear 13 G is moving along the inner periphery of the internal gear 13 G. As a result, the external gear 12 G tiltably moves relative to the internal gear 13 G.
- the external gear 12 G has one fewer tooth or less compared to the internal gear 13 G
- the external gear 12 G rotates one turn on the inner periphery of the internal gear 13 G and the internal gear 13 G rotates by an angle (i.e., an angle shown by an arrow in FIG. 6B ) corresponding to a difference of the number of teeth between the internal gear 13 G and the external gear 12 G when the drive shaft 11 rotates one turn, for example.
- an angle i.e., an angle shown by an arrow in FIG. 6B
- the second frames 2 move tiltably along with rotations of the drive shafts 11 , thereby arbitrarily specifying the angle of the seat back B relative to the seat cushion A.
- each of the angle adjustment units C of the present embodiment the meshed position between the external gear 12 G and the internal gear 13 G moves along the inner periphery of the internal gear 13 G.
- each of the second frames 2 in addition to each of the upper gear plates 12 including the external gear 12 G is displaced in a direction to approach and separate from the support axis X.
- each of the upper gear plates 12 and each of the lower gear plates 13 are connected to each other via the second power transmission mechanism so as to be integrally tiltable about the support axis X.
- the upper gear plates 12 and the lower gear plates 13 are integrally tilted forward to the utmost limit about the support axis X by the biasing force of the torsion springs 18 .
- front stoppers 31 that determine a forward tilt limit of the upper gear plates 12 and the lower gear plates 13 are provided at the respective first frames 1 .
- forward tilt contact portions 2 S that make contact with the front stoppers 31 are formed at the respective second frames 2 .
- each of the front stoppers 31 is made of a plate member fixed to the first frame 1 by spot welding, or the like.
- the front stoppers 31 having the plate shape also serve as reinforcements of the first frame 1 .
- the front stopper 31 includes a contact surface 31 S at an upper end linearly and horizontally extending.
- a virtual straight line V obtained by an extension of the contact surface 31 S is configured to pass through a vicinity of the support axis X. It is desirable that the virtual straight line V passes through the support axis X, however, the virtual straight line V is still effective even when passing through the vicinity of the support axis X.
- the forward tilt contact portions 2 S constitute portions of the second frames 2 .
- Each of the forward tilt contact portions 2 S does not include a specific structure for a contact according to the present embodiment. However, for example, a projection, a contact member, or the like may be formed at the forward tilt contact portion 2 S for the contact with the front stopper 31 .
- the seat back B is also tiltable forward by the driving force of the electric motor M of the angle adjustment unit C.
- an angle achieved immediately before each of the forward tilt contact portions 2 S makes contact with each of the front stoppers 31 is specified to be a forward operation limit of the seat back B.
- the electric motor M is automatically stopped by an electric control.
- the seat back B may be configured to be tilted rearward so as to be positioned substantially horizontally by the use of the driving force of the electric motor M. Such configuration is realized by an operation of a switch, for example.
- the electric motor M is automatically stopped by the electric control.
- a space in the rear of the seat back B is open. Therefore, for example, a wide space is ensured for a user to get in or out of a seat arranged behind the present seat to thereby ease a walk-in operation, and the like.
- the upper gear plates 12 and the lower gear plates 13 are integrally tilted rearward to the utmost limit about the support axis X.
- back stoppers 32 are provided at the first frames 1 respectively at positions adjoined to the lower gear plates 13 .
- Rearward tilt contact portions 13 S making contact with the back stoppers 32 are formed at the respective lower gear plates 13 .
- Each of the back stoppers 32 having a column shape is provide at the first frame 1 in a projecting manner.
- the back stopper 32 also serves as a member supporting the fixed plate 14 to the first frame 1 and further serves as a connection member connecting the front stopper 31 to the first frame 1 (see FIG. 1 ).
- the rearward tilt contact portion 13 S is a portion of the end surface of the lower gear plate 13 .
- the rearward tilt contact portion 13 S does not include a specific structure for a contact according to the present embodiment. Alternatively, a member for the contact may be separately provided from the lower gear plate 13 .
- the first distance D 1 is greater than the second distance D 2 (i.e., D 1 >D 2 ).
- D 1 >D 2 a distance between the contact position between the front stopper 31 and the forward tilt contact portion 2 S and the support axis X
- the first distance D 1 is greater than the second distance D 2 (i.e., D 1 >D 2 ).
- a value of the first distance D 1 varies depending on the tilt angle of the seat back B relative to the seat cushion A by the angle adjustment units C as mentioned above.
- the relationship between the first distance D 1 and the second distance D 2 i.e., D 1 >D 2
- the relationship of D 1 >D 2 is an example of the present embodiment and may not be necessarily achieved.
- the position of the forward tilt contact portion 2 S formed at each of the second frames 2 is displaced relative to the support axis X in the direction to approach and separate therefrom by the operation of the angle adjustment units C and therefore the contact position of the forward tilt contact portion 2 S relative to the front stopper 31 varies upon the forward tilt of the seat back B with the lock mechanism L in the unlocked state.
- the variation of the contact position of the forward tilt contact portion 2 S relative to the front stopper 31 corresponds to the direction to approach and separate from the support axis X.
- the tilt angle of the seat back B is prevented from varying to thereby retain the seat back B at a desirable angle.
- the tilt amount i.e., the tilt angle of the second frames 2 relative to the first frames 1 is selectable by the driving force of the electric motor M of the angle adjustment unit C.
- the forward tilt contact portions 2 S of the second frames 2 make contact with the respective front stoppers 31 , thereby determining the limit of the tilt operation.
- the forward tilt contact portions 2 S make contact with the respective front stoppers 31 on the respective virtual lines V, thereby restraining the tilt angle of the seat back B from varying.
- the seat back B is maintained at a position of the forward tilt limit. Accordingly, in a case where the position of the seat back B varies relative to the support axis X serving as the axial center of the tilt operation of the seat back B when the reclining operation of the seat is adjusted by the electric motor M, the forward operation of the seat back B is restricted at an appropriate position in a state where the seat back B is tilted forward with the lock mechanisms L each in the unlocked state.
- the first frame 1 is constituted by a plate member and the front stopper 31 serves as a reinforcement member connected to the first frame 1 .
- the contact surface 31 S of the front stopper 31 is easily linearly formed while the reinforcement of the first frame 1 is conducted.
- the seat reclining apparatus further includes the back stopper 32 arranged adjacent to the lower gear plate 13 and specifying the rearward tilt limit of the seat back B by making contact with the rearward tilt contact portion 13 S provided at the lower gear plate 13 in a state where the lock mechanism L is in the unlocked state, the back stopper 32 serving as a connection member connecting the front stopper 31 to the first frame 1 .
- the rearward tilt contact portion formed at the lower gear plate 13 makes contact with the back stopper 32 to thereby determine the rearward operation limit.
- the back stopper 32 is provided adjacent to the rearward tilt contact portion 13 S to thereby restrain an enlargement of the rearward tilt contact portion 13 S, i.e., an enlargement of the lower gear plate 13 .
- the back stopper 32 also serves as a member to connect the front stopper 31 to the first frame 1 , an increase of the number of components may be restrained.
- the lock mechanism L includes the lock arm 19 rotatably supported by the front stopper 31 and being engageable and disengageable relative to the lower gear plate 13 by a rotation of the lock arm 9 .
- the angle adjustment unit C includes the internal gear 13 G formed at the lower gear plate 13 , the external gear 12 G formed at the upper gear plate 12 connected to the second frame 2 and having fewer teeth compared to the internal gear 13 G, and the pair of wedge pieces 25 integrally rotating with the drive shaft 11 which is driven to rotate by the electric motor M, a portion of the internal gear 13 G engaging with a portion of the external gear 12 G, the external gear 12 G being rotatably mounted at an outer periphery of the pair of wedge pieces 25 .
- the seat reclining apparatus further includes the second power transmission mechanism moving the meshed position between the external gear 12 G and the internal gear 13 G along an inner periphery of the internal gear 13 G by a rotational force of the pair of wedge pieces 25 when the electric motor M is driven, the second power transmission mechanism causing the upper gear frame 12 to tilt by an angle corresponding to a difference of the number of teeth between the external gear 12 G and the internal gear 13 G in a case where the external gear 12 G rotates one turn along the inner periphery of the internal gear 13 G, the upper gear frame 12 being displaced in the direction to approach and separate from the support axis X when the meshed position between the external gear 12 G and the internal gear 13 G moves along the inner periphery of the internal gear 13 G.
- the upper gear plate 12 is displaced in the direction to approach and separate from the support axis X, which results in a relatively simple structure with two gears for obtaining a large speed reduction.
- the variation of the forward operation limit when the seat back B is tilted forward may be restrained.
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- Engineering & Computer Science (AREA)
- Aviation & Aerospace Engineering (AREA)
- Transportation (AREA)
- Mechanical Engineering (AREA)
- Chairs For Special Purposes, Such As Reclining Chairs (AREA)
- Seats For Vehicles (AREA)
Abstract
A seat reclining apparatus includes a support frame tiltable about a support axis relative to a first frame, an angle adjustment unit causing a second frame to tiltably move forward or rearward relative to the support frame by a driving force of an actuator, the second frame being displaced in a direction to approach and separate from the support axis, a lock mechanism selectively operated to an unlocked state and a locked state, and a front stopper provided at the first frame to specify a forward tilt limit of the seat back by making contact with a forward tilt contact portion provided at the second frame in a state where the lock mechanism is in the unlocked state, the front stopper including a linearly-shaped contact surface that makes contact with the forward tilt contact portion and that matches or approximates a virtual straight line passing through the support axis.
Description
- This application is based on and claims priority under 35 U.S.C. §119 to Japanese Patent Application 2009-085538, filed on Mar. 31, 2009, the entire content of which is incorporated herein by reference.
- This disclosure relates to a seat reclining apparatus.
- A known seat reclining apparatus includes a mechanism for adjusting a tilt angle of a seat back relative to a seat base by means of a driving force of an actuator and a stopper structure for determining a tilt limit of the seat back when a locked state between the seat back and the seat base is released. Such seat reclining apparatus is disclosed in JP61-48311A (hereinafter referred to as Reference 1). A reclining apparatus disclosed in
Reference 1 includes a base provided at a seat cushion, an arm provided at a seat back so as to be rotatably connected to each other, and a sub plate arranged at a position where the sub plate is sandwiched between the base and the arm. The reclining apparatus further includes a lock mechanism of a planetary gear type between the sub plate and the arm. A sun gear included in the lock mechanism is manually operated so as to achieve a stepless reclining adjustment of the seat back relative to the seat base. - According to the reclining apparatus disclosed in
Reference 1, a sub plate holding member is provided to obtain a locked state where the sub plate is connected to the base as a unit and an unlocked state where the sub plate is disconnected from the base. When the sub plate holding member is rotated in a predetermined direction by a manual operation to thereby release an engagement of an engagement projection of the sub plate holding member with the sub plate, the sub plate is disconnected from the base. Then, a locked state of the arm, which is connected to the sub plate by the lock mechanism, relative to the base is released. As a result, the seat back is tiltable forward. Afterwards, when the seatback is pulled back (i.e., returned), the sub plate holding member is rotated in a direction opposite from the aforementioned predetermined direction so that the engagement projection of the sub plate holding member engages with the sub plate. As a result, the sub plate, in addition to the arm, is locked at an original tilt position relative to the base. - In addition, according to a seat reclining apparatus for a vehicle disclosed in JP2002-65388A (hereinafter referred to as Reference 2), a driving force of a drive mechanism on which a speed reduction is conducted is transmitted to a seat back. Specifically, the seat reclining apparatus disclosed in
Reference 2 includes lower arms attached to respective side portions of a seat cushion via lower brackets and upper arms attached to respective side portions of the seat back. Each of the lower arms is formed by an annular internal gear portion. Each of the upper arms is formed by an external gear portion that projects from a general flat portion of the upper arm attached to the seat back. The external gear portion of the upper arm has one fewer tooth or less compared to the internal gear portion of the lower arm. The external gear portion of the upper arm partially engages with the internal gear portion of the lower arm. - The seat reclining apparatus disclosed in
Reference 2 further includes a pair of wedges and the like by means of which the driving force of the drive mechanism is transmitted to the external gear portion of the upper arm. Then, the external gear portion rotates about an axial center eccentric to a center of a drive shaft. As a result, a meshed position of the external gear portion with the internal gear portion moves sequentially along an inner periphery of the internal gear portion to thereby adjust an angle of the upper arm relative to the lower bracket. - According to the seat reclining apparatus disclosed in
Reference 2, the speed reduction of the driving force of the drive mechanism is achieved by the rotation of the external gear portion about a position eccentric to the center of the drive shaft, thereby specifying a position of the seat back. Thus, in a case where the meshed position between the external gear portion and the internal gear portion moves in the circumferential direction by the driving of the drive mechanism (i.e., the actuator), a portion of the internal gear portion with which the external gear portion is meshed is displaced away from the center of the drive shaft. - In addition, according to the seat reclining apparatus disclosed in
Reference 2, in a case where the seat back is tilted forward so as to achieve a walk-in function in the same way as the apparatus disclosed inReference 1, a certain structure is required for supporting a reclining operation mechanism including the actuator, the external gear portion, the internal gear portion and the seat back to be rotatable about an axial center relative to the seat cushion. Then, the entire reclining operation mechanism is tilted forward by a release of a locked state between the seat back and the seat cushion in a case where the seat back is tilted forward. - When the entire reclining operation mechanism is tilted forward, a stopper is required to determine a forward tilt limit. For example, it is considerable to use a structure where a frame of the seat back makes contact with the stopper provided at the seat cushion. However, depending on the tilt angle of the seat back that is specified by the reclining operation mechanism, a contact position of the frame of the seat back with the stopper may vary, which fails to maintain the forward tilt limit at a target forward tilt angle.
- In addition, the aforementioned reclining operation mechanism may often include a spring for biasing the seat back in the forward tilt direction. In a case where it is impossible to restrict the forward tilt of the seat back at the target forward tilt angle, an upper surface of the seat cushion strongly makes contact with a front surface of the seat back by the biasing force of the spring before the forward tilt of the seat back is restricted or the forward tilt angle of the seat back is insufficient at a time when the locked state between the seat back and the seat cushion is released.
- A need thus exists for a seat reclining apparatus which is not susceptible to the drawback mentioned above.
- According to an aspect of this disclosure, a seat reclining apparatus includes a support frame tiltable about a support axis relative to a first frame constituting a seat cushion, an angle adjustment unit causing a second frame constituting a seat back to tiltably move forward or rearward relative to the support frame by a driving force of an actuator, the second frame being displaced in a direction to approach and separate from the support axis in a case where the second frame tiltably moves forward or rearward relative to the support frame, a lock mechanism selectively operated to an unlocked state where the support frame is allowed to integrally tiltably move with the angle adjustment unit about the support axis and a locked state where the support frame is prohibited to integrally tiltably move with the angle adjustment unit, and a front stopper provided at the first frame to specify a forward tilt limit of the seat back by making contact with a forward tilt contact portion provided at the second frame in a state where the lock mechanism is in the unlocked state, the front stopper including a linearly-shaped contact surface that makes contact with the forward tilt contact portion and that matches or approximates a virtual straight line passing through the support axis.
- The foregoing and additional features and characteristics of this disclosure will become more apparent from the following detailed description considered with the reference to the accompanying drawings, wherein:
-
FIG. 1 is a side view illustrating a first frame and a second frame of a seat according to an embodiment disclosed here; -
FIG. 2 is a plan view illustrating a structure of the first frame; -
FIG. 3 is a cross-sectional view taken along line III-III inFIG. 2 ; -
FIG. 4 is a cross-sectional view taken along the line IV-IV inFIG. 2 ; -
FIG. 5 is a cross-sectional view illustrating an angle adjustment unit according to the embodiment disclosed here; -
FIGS. 6A and 6B are cross-sectional views each illustrating a meshed state between an internal gear and an external gear according to the embodiment disclosed here; -
FIG. 7 is a side view illustrating a lock mechanism in a locked state according to the embodiment disclosed here; -
FIG. 8A is a side view illustrating a state where a front stopper and a forward tilt contact portion make contact with each other andFIG. 8B is a side view illustrating a state where a back stopper and a rearward tilt contact portion make contact with each other according to the embodiment disclosed here; -
FIG. 9 is an exploded perspective view illustrating a structure of the right angle adjustment unit; and -
FIG. 10 is an exploded perspective view illustrating a structure of the left angle adjustment unit. - An embodiment disclosed here will be explained with reference to the attached drawings.
- [Overall Structure]
- As illustrated in
FIGS. 1 and 2 , a reclining-type seat for a vehicle such as a passenger car includes a seat cushion A of which a center portion in a width direction of the vehicle is formed by a seated surface and a seat back B attached at a rear edge of the seat cushion A so as to be tiltable in a longitudinal direction of the vehicle. In the embodiment, directions and orientations such as left, right, front, rear, top, and bottom correspond to those when viewed from a passenger seated on the seat for a vehicle. - The seat cushion A includes two first frames (i.e., left and right first frames) 1 constituting left and right side portions of the seat cushion A. The seat back B includes two second frames (i.e., left and right second frames) 2 constituting left and right side portions of the seat back B. The
first frames 1 and thesecond frames 2 are tiltably connected to each other at left and right sides of the seat, respectively, about a support axis X. The seat also includes two angle adjustment units (i.e., left and right angle adjustment units) C at connecting portions between thefirst frames 1 and thesecond frames 2 respectively so as to arbitrarily specify a tilt amount (i.e., a tilt angle) of thesecond frames 2 relative to thefirst frames 1 by means of a driving force of a single actuator. Further, the seat includes two lock mechanisms (i.e., left and right lock mechanisms) L that achieve a locked state where each of thesecond frames 2 is maintained at a fixed tilt angle relative to each of thefirst frames 1 and an unlocked state where each of thesecond frames 2 is tiltable relative to each of thefirst frames 1. A seat reclining apparatus according to the present embodiment is constituted by a structure where the seat is tiltable by thefirst frames 1 and thesecond frames 2, the angle adjustment units C, and the lock mechanisms L. - As illustrated in
FIGS. 1 to 5 , 9, and 10, each of the angle adjustment units C includes anupper gear plate 12 serving as a tilt frame, alower gear plate 13 serving as a support frame, afixed plate 14 and alock release arm 15 that are arranged in this order along an axial center X (which is equal to the support axis X) of each drive shaft 11 (i.e., each of left and right drive shafts) rotatably supported by thefirst frame 1. According to the present embodiment, thelock release arm 15 is provided at only one of the angle adjustment units C (for example, at the right angle adjustment unit C). - Inner ends of the left and
right drive shafts 11 are connected to anintermediate shaft 16. An outer end of one of thedrive shafts 11 is provided with a first power transmission mechanism where agear reduction mechanism 17 performs a speed reduction on a driving force of an electric motor M serving as the actuator and performs a power transmission of the resulting driving force. - Left and right torsion springs 18, each having a coil shape, are provided at facing portions of the left and right first frames 1. One end of each of the torsion springs 18 engages with a
support block 1A of thefirst frame 1 while the other end of each of the torsion springs 18 engages with theupper gear plate 12. As a result, thesecond frames 2 are biased forward. - As illustrated in
FIGS. 7 , 8A and 8B, each of thelower gear plates 13 includes multiplelock recess portions 13A at a lower side. Each lock arm (i.e., each of left and right lock arms) 19 including multiple protrudingportions 19A engageable and disengageable relative to the multiplelock recess portions 13A is supported at a side surface of each of the left and right first frames 1 so as to be rotatable about alock support shaft 20. Thelock arm 19 includes aguide portion 19B having a cutout shape along which acontrol roller 22 is movable. Each of the aforementioned lock mechanisms L is obtained by engagement and disengagement between thelock arm 19 and thelower gear plate 13. - The
lock release arm 15 is movably supported about the support axis X at an outer wall portion of one of the fixedplates 14, specifically, the right fixedplate 14. Then, a linkingarm 35 is provided at a position facing thelock release arm 15 across the rightfirst frame 1. The linkingarm 35 is movable about the support axis X. Theright control roller 22 is supported at both ends by thelock release arm 15 and theright linking arm 35. Anarm portion 15A of thelock release arm 15 is provided with a grip of which a user takes hold. - An
operation arm 36 is movably supported about the support axis X at an outer wall portion of the other of the fixedplates 14, specifically, the left fixedplate 14. Theoperation arm 36 is provided at a position symmetrical to a position where thelock release arm 15 is provided. Theleft control roller 22 is supported at both ends by theoperation arm 36 and theleft linking arm 35. - The left and right linking
arms 35 are connected to a linkingshaft 23 within which theintermediate shaft 16 is coaxially fitted. Theleft linking arm 35 and theoperation arm 36 receive a biasing force from a lock spring 21 (seeFIG. 7 ) to thereby maintain thecontrol roller 22 at a locked position. - The
guide portion 19B of each of thelock arms 19 includes a lock area and an unlock area continuously formed as illustrated inFIGS. 7 , 8A and 8B. Specifically, in a case where thecontrol roller 22 is positioned at the lock area as illustrated inFIG. 7 , the protrudingportions 19A engage with the respectivelock recess portions 13A. In a case where thecontrol roller 22 is positioned at the unlock area as illustrated inFIGS. 8A and 8B , the protrudingportions 19A of thelock arm 19 disengage from the respectivelock recess portions 13A. - When the
arm portion 15A of thelock release arm 15 is manually operated upward in a state where each of the lock mechanisms L is in the locked state, i.e., the protrudingportions 19A engage with the respectivelock recess portions 13A, thecontrol roller 22 moves along theguide portion 19B from the lock area to the unlock area. Because the left and right linkingarms 35 are connected to each other by means of the linkingshaft 23, the left andright control rollers 22 both move to the respective unlock areas from the respective lock areas at the same time. As a result, the left and right lockarms 19 are allowed to move in a direction where the locked states of both of the lock mechanisms L are released. Then, as illustrated inFIGS. 8A and 8B , the protrudingportions 19A of each of thelock arms 19 disengage from the respectivelock recess portions 13A of each of thelower gear plates 13, thereby bringing each of the lock mechanisms L to the unlocked state. - Each of the lock mechanisms L is brought to the unlocked state so that the seat back B is tilted forward by the biasing force of the left and right torsion springs 18. In addition, in a case where a force to tilt the seat back B rearward is applied thereto when each of the lock mechanisms L is brought to the unlocked state, the seat back B is tilted rearward against the biasing force of the left and right torsion springs 18.
- [Angle adjustment unit]
- The angle adjustment unit C transmits the driving force of the electric motor M from the
gear reduction mechanism 17 to a second power transmission mechanism serving as a power transmission mechanism provided between theupper gear plate 12 and thelower gear plate 13. Then, the speed reduction is conducted on the driving force by the second power transmission mechanism to thereby tilt theupper gear plate 12 relative to thelower gear plate 13. - Specifically, as illustrated in
FIGS. 3 to 6 , 9 and 10, each of thelower gear plates 13 is formed by a circular-shaped gear accommodating portion at a center. The gear accommodating portion is formed by press working, or the like, and is dent in a thickness direction of thelower gear plate 13. Asupport boss portion 13B is formed at a center of the gear accommodating portion by burring, or the like so as to protrude along the support axis X. Abore 13H is formed at an inner periphery of thesupport boss portion 13B. In addition, an internally toothed gear (internal gear) 13G is integrally formed at an inner periphery of the gear accommodating portion of thelower gear plate 13 so as to be coaxial with thesupport boss portion 13B. - Each of the
upper gear plates 12 is formed by a circular-shaped bulged portion at a center. The bulged portion is formed by a press working, or the like, and is dent in a thickness direction of theupper gear plate 12. A circular-shapedbore 12H penetrates through a center of the bulged portion. In addition, an externally toothed gear (external gear) 12G is integrally formed at an outer periphery of the bulged portion of theupper gear plate 12 so as to be coaxial with thebore 12H. Theexternal gear 12G has one fewer tooth or less compared to theinternal gear 13G. - A pair of
wedge pieces 25 is arranged at an outer periphery of thesupport boss portion 13B so as to be slidable on the outer periphery thereof in a circumferential direction. Thewedge pieces 25 are examples of eccentric members. Each of thewedge pieces 25 is integrally formed by a projectingportion 25A along the support axis X. A loop-shapedspring 26 is disposed to bias the pair ofwedge pieces 25 to separate them each other in the circumferential direction of thesupport boss portion 13B. Acam plate 27 including anengagement recess portion 27A that makes contact with the projectingportions 25A of the pair ofwedge pieces 25 so as to apply a rotational force thereto is provided at each of thedrive shafts 11. The pair ofwedge pieces 25 collectively forms an outer peripheral shape that partially constitutes a periphery eccentric to the axial center X of each of thedrive shafts 11 when viewed in a direction along the axial center X. The pair ofwedge pieces 25 is arranged to make contact with an inner periphery of thebore 12H of each of theupper gear plates 12. - Accordingly, a center of the
external gear 12G formed at each of theupper gear plates 12 is positioned eccentric to the axial center X of thedrive shaft 11. Consequently, a portion of theinternal gear 13G of each of thelower gear plates 13 is meshed with a portion of theexternal gear 12G of each of theupper gear plates 12. - In the aforementioned arrangement between the
internal gear 13G and theexternal gear 12G, in a case where each of thedrive shafts 11 is driven to rotate, end faces of theengagement recess portion 27A of thecam plate 27 make contact with the respective projectingportions 25A of the pair ofwedge pieces 25. The rotational force of thedrive shaft 11 is transmitted to the pair ofwedge pieces 25 via the contacting portion between the cam plate 27 (i.e., theengagement recess portion 27A) and the pair ofwedge pieces 25, thereby slidably rotating the pair ofwedge pieces 25 on the outer periphery of thesupport boss portion 13B in the circumferential direction. According to such rotation of the pair ofwedge pieces 25, the center of theexternal gear 12G of theupper gear plate 12 moves along a circumferential locus so as to be away from the axial center X of thedrive shaft 11. While the center of theexternal gear 12G is moving, the meshed position between theexternal gear 12G and theinternal gear 13G is moving along the inner periphery of theinternal gear 13G. As a result, theexternal gear 12G tiltably moves relative to theinternal gear 13G. - According to a principle of the speed reduction of the second power transmission mechanism, because the
external gear 12G has one fewer tooth or less compared to theinternal gear 13G, theexternal gear 12G rotates one turn on the inner periphery of theinternal gear 13G and theinternal gear 13G rotates by an angle (i.e., an angle shown by an arrow inFIG. 6B ) corresponding to a difference of the number of teeth between theinternal gear 13G and theexternal gear 12G when thedrive shaft 11 rotates one turn, for example. As a result, a large speed reduction by a large reduction gear ratio is achieved. As a result, according to the second power transmission mechanism of the present embodiment, thesecond frames 2 move tiltably along with rotations of thedrive shafts 11, thereby arbitrarily specifying the angle of the seat back B relative to the seat cushion A. - Specifically, according to each of the angle adjustment units C of the present embodiment, the meshed position between the
external gear 12G and theinternal gear 13G moves along the inner periphery of theinternal gear 13G. Thus, each of thesecond frames 2 in addition to each of theupper gear plates 12 including theexternal gear 12G is displaced in a direction to approach and separate from the support axis X. - [Tilt limiting mechanism]
- In a case where the left and right lock
arms 19 are operated in a direction where the locked state of each of the lock mechanisms L is released by an operation of thelock release arm 15 so that the lock mechanism L is brought to the unlocked state, each of theupper gear plates 12 and each of thelower gear plates 13 are connected to each other via the second power transmission mechanism so as to be integrally tiltable about the support axis X. - Thus, in a case where the lock mechanisms L are each brought to the unlocked state while a user is not seated on the seat, the
upper gear plates 12 and thelower gear plates 13 are integrally tilted forward to the utmost limit about the support axis X by the biasing force of the torsion springs 18. Then,front stoppers 31 that determine a forward tilt limit of theupper gear plates 12 and thelower gear plates 13 are provided at the respectivefirst frames 1. In addition, forwardtilt contact portions 2S that make contact with thefront stoppers 31 are formed at the respectivesecond frames 2. - As illustrated in
FIG. 7 , each of thefront stoppers 31 is made of a plate member fixed to thefirst frame 1 by spot welding, or the like. Thefront stoppers 31 having the plate shape also serve as reinforcements of thefirst frame 1. Thefront stopper 31 includes acontact surface 31S at an upper end linearly and horizontally extending. A virtual straight line V obtained by an extension of thecontact surface 31S is configured to pass through a vicinity of the support axis X. It is desirable that the virtual straight line V passes through the support axis X, however, the virtual straight line V is still effective even when passing through the vicinity of the support axis X. - The forward
tilt contact portions 2S constitute portions of the second frames 2. Each of the forwardtilt contact portions 2S does not include a specific structure for a contact according to the present embodiment. However, for example, a projection, a contact member, or the like may be formed at the forwardtilt contact portion 2S for the contact with thefront stopper 31. - According to the seat reclining apparatus of the present embodiment, the seat back B is also tiltable forward by the driving force of the electric motor M of the angle adjustment unit C. In this case, an angle achieved immediately before each of the forward
tilt contact portions 2S makes contact with each of thefront stoppers 31 is specified to be a forward operation limit of the seat back B. When the seat back B reaches the forward operation limit, the electric motor M is automatically stopped by an electric control. In addition, the seat back B may be configured to be tilted rearward so as to be positioned substantially horizontally by the use of the driving force of the electric motor M. Such configuration is realized by an operation of a switch, for example. When the seat back B reaches a rearward operation limit, the electric motor M is automatically stopped by the electric control. - When the seat back B is tilted to the forward operation limit, a space in the rear of the seat back B is open. Therefore, for example, a wide space is ensured for a user to get in or out of a seat arranged behind the present seat to thereby ease a walk-in operation, and the like.
- In a case where the angle adjustment units C are each brought in the unlocked state when the user, seated on the seat, leans against the seat back B, the
upper gear plates 12 and thelower gear plates 13 are integrally tilted rearward to the utmost limit about the support axis X. In order to determine a rearward tilt limit as illustrated inFIGS. 8A and 8B , backstoppers 32 are provided at thefirst frames 1 respectively at positions adjoined to thelower gear plates 13. Rearwardtilt contact portions 13S making contact with theback stoppers 32 are formed at the respectivelower gear plates 13. - Each of the
back stoppers 32 having a column shape is provide at thefirst frame 1 in a projecting manner. Theback stopper 32 also serves as a member supporting the fixedplate 14 to thefirst frame 1 and further serves as a connection member connecting thefront stopper 31 to the first frame 1 (seeFIG. 1 ). The rearwardtilt contact portion 13S is a portion of the end surface of thelower gear plate 13. The rearwardtilt contact portion 13S does not include a specific structure for a contact according to the present embodiment. Alternatively, a member for the contact may be separately provided from thelower gear plate 13. - As illustrated in
FIGS. 8A and 8B , when assuming that a distance between the contact position between thefront stopper 31 and the forwardtilt contact portion 2S and the support axis X is a first distance D1 and a distance between the contact position between theback stopper 32 and the rearwardtilt contact portion 13S and the support shaft X is a second distance D2, the first distance D1 is greater than the second distance D2 (i.e., D1>D2). A value of the first distance D1 varies depending on the tilt angle of the seat back B relative to the seat cushion A by the angle adjustment units C as mentioned above. However, the relationship between the first distance D1 and the second distance D2, i.e., D1>D2, is maintained. At this time, the relationship of D1>D2 is an example of the present embodiment and may not be necessarily achieved. - According to the aforementioned structure, the position of the forward
tilt contact portion 2S formed at each of thesecond frames 2 is displaced relative to the support axis X in the direction to approach and separate therefrom by the operation of the angle adjustment units C and therefore the contact position of the forwardtilt contact portion 2S relative to thefront stopper 31 varies upon the forward tilt of the seat back B with the lock mechanism L in the unlocked state. However, the variation of the contact position of the forwardtilt contact portion 2S relative to thefront stopper 31 corresponds to the direction to approach and separate from the support axis X. Thus, the tilt angle of the seat back B is prevented from varying to thereby retain the seat back B at a desirable angle. - That is, the tilt amount, i.e., the tilt angle of the
second frames 2 relative to thefirst frames 1 is selectable by the driving force of the electric motor M of the angle adjustment unit C. In addition, in a case where the seat back B is tilted forward while the lock mechanisms L are each in the unlocked state, the forwardtilt contact portions 2S of thesecond frames 2 make contact with the respectivefront stoppers 31, thereby determining the limit of the tilt operation. Further, even when the distance between each of thesecond frames 2 and the support axis X varies depending on the tilt angle specified by the angle adjustment units C, the forwardtilt contact portions 2S make contact with the respectivefront stoppers 31 on the respective virtual lines V, thereby restraining the tilt angle of the seat back B from varying. The seat back B is maintained at a position of the forward tilt limit. Accordingly, in a case where the position of the seat back B varies relative to the support axis X serving as the axial center of the tilt operation of the seat back B when the reclining operation of the seat is adjusted by the electric motor M, the forward operation of the seat back B is restricted at an appropriate position in a state where the seat back B is tilted forward with the lock mechanisms L each in the unlocked state. - According to the aforementioned embodiment, the
first frame 1 is constituted by a plate member and thefront stopper 31 serves as a reinforcement member connected to thefirst frame 1. - Because the
front stopper 31 is formed by the reinforcement member, thecontact surface 31S of thefront stopper 31 is easily linearly formed while the reinforcement of thefirst frame 1 is conducted. - In addition, according to the aforementioned embodiment, the seat reclining apparatus further includes the
back stopper 32 arranged adjacent to thelower gear plate 13 and specifying the rearward tilt limit of the seat back B by making contact with the rearwardtilt contact portion 13S provided at thelower gear plate 13 in a state where the lock mechanism L is in the unlocked state, theback stopper 32 serving as a connection member connecting thefront stopper 31 to thefirst frame 1. - Accordingly, in a case where the seat back B is tilted rearward with the lock mechanism L in the unlocked state, the rearward tilt contact portion formed at the
lower gear plate 13 makes contact with theback stopper 32 to thereby determine the rearward operation limit. Theback stopper 32 is provided adjacent to the rearwardtilt contact portion 13S to thereby restrain an enlargement of the rearwardtilt contact portion 13S, i.e., an enlargement of thelower gear plate 13. In addition, because theback stopper 32 also serves as a member to connect thefront stopper 31 to thefirst frame 1, an increase of the number of components may be restrained. - Further, according to the aforementioned embodiment, the lock mechanism L includes the
lock arm 19 rotatably supported by thefront stopper 31 and being engageable and disengageable relative to thelower gear plate 13 by a rotation of the lock arm 9. - Furthermore, according to the aforementioned embodiment, the angle adjustment unit C includes the
internal gear 13G formed at thelower gear plate 13, theexternal gear 12G formed at theupper gear plate 12 connected to thesecond frame 2 and having fewer teeth compared to theinternal gear 13G, and the pair ofwedge pieces 25 integrally rotating with thedrive shaft 11 which is driven to rotate by the electric motor M, a portion of theinternal gear 13G engaging with a portion of theexternal gear 12G, theexternal gear 12G being rotatably mounted at an outer periphery of the pair ofwedge pieces 25. The seat reclining apparatus further includes the second power transmission mechanism moving the meshed position between theexternal gear 12G and theinternal gear 13G along an inner periphery of theinternal gear 13G by a rotational force of the pair ofwedge pieces 25 when the electric motor M is driven, the second power transmission mechanism causing theupper gear frame 12 to tilt by an angle corresponding to a difference of the number of teeth between theexternal gear 12G and theinternal gear 13G in a case where theexternal gear 12G rotates one turn along the inner periphery of theinternal gear 13G, theupper gear frame 12 being displaced in the direction to approach and separate from the support axis X when the meshed position between theexternal gear 12G and theinternal gear 13G moves along the inner periphery of theinternal gear 13G. - Accordingly, the
upper gear plate 12 is displaced in the direction to approach and separate from the support axis X, which results in a relatively simple structure with two gears for obtaining a large speed reduction. Specifically, according to the seat reclining apparatus of the embodiment, while the aforementioned second power transmission mechanism is used, the variation of the forward operation limit when the seat back B is tilted forward may be restrained. - The principles, preferred embodiment and mode of operation of the present invention have been described in the foregoing specification. However, the invention which is intended to be protected is not to be construed as limited to the particular embodiments disclosed. Further, the embodiments described herein are to be regarded as illustrative rather than restrictive. Variations and changes may be made by others, and equivalents employed, without departing from the spirit of the present invention. Accordingly, it is expressly intended that all such variations, changes and equivalents which fall within the spirit and scope of the present invention as defined in the claims, be embraced thereby.
Claims (13)
1. A seat reclining apparatus comprising:
a support frame tiltable about a support axis relative to a first frame constituting a seat cushion;
an angle adjustment unit causing a second frame constituting a seat back to tiltably move forward or rearward relative to the support frame by a driving force of an actuator, the second frame being displaced in a direction to approach and separate from the support axis in a case where the second frame tiltably moves forward or rearward relative to the support frame;
a lock mechanism selectively operated to an unlocked state where the support frame is allowed to integrally tiltably move with the angle adjustment unit about the support axis and a locked state where the support frame is prohibited to integrally tiltably move with the angle adjustment unit; and
a front stopper provided at the first frame to specify a forward tilt limit of the seat back by making contact with a forward tilt contact portion provided at the second frame in a state where the lock mechanism is in the unlocked state, the front stopper including a linearly-shaped contact surface that makes contact with the forward tilt contact portion and that matches or approximates a virtual straight line passing through the support axis.
2. The seat reclining apparatus according to claim 1 , wherein the first frame is constituted by a plate member and the front stopper serves as a reinforcement member connected to the first frame.
3. The seat reclining apparatus according to claim 1 , further comprising a back stopper arranged adjacent to the support frame and specifying a rearward tilt limit of the seat back by making contact with a rearward tilt contact portion provided at the support frame in a state where the lock mechanism is in the unlocked state, the back stopper serving as a connection member connecting the front stopper to the first frame.
4. The seat reclining apparatus according to claim 2 , further comprising a back stopper arranged adjacent to the support frame and specifying a rearward tilt limit of the seat back by making contact with a rearward tilt contact portion provided at the support frame in a state where the lock mechanism is in the unlocked state, the back stopper serving as a connection member connecting the front stopper to the first frame.
5. The seat reclining apparatus according to claim 1 , wherein the lock mechanism includes a lock arm rotatably supported by the front stopper and being engageable and disengageable relative to the support frame by a rotation of the lock arm.
6. The seat reclining apparatus according to claim 2 , wherein the lock mechanism includes a lock arm rotatably supported by the front stopper and being engageable and disengageable relative to the support frame by a rotation of the lock arm.
7. The seat reclining apparatus according to claim 3 , wherein the lock mechanism includes a lock arm rotatably supported by the front stopper and being engageable and disengageable relative to the support frame by a rotation of the lock arm.
8. The seat reclining apparatus according to claim 4 , wherein the lock mechanism includes a lock arm rotatably supported by the front stopper and being engageable and disengageable relative to the support frame by a rotation of the lock arm.
9. The seat reclining apparatus according to claim 1 , wherein the angle adjustment unit includes an internal gear formed at the support frame, an external gear formed at a tilt frame connected to the second frame and having fewer teeth compared to the internal gear, and an eccentric member integrally rotating with a drive shaft which is driven to rotate by the actuator, a portion of the internal gear engaging with a portion of the external gear, the external gear being rotatably mounted at an outer periphery of the eccentric member, and
the seat reclining apparatus further comprises a power transmission mechanism moving a meshed position between the external gear and the internal gear along an inner periphery of the internal gear by a rotational force of the eccentric member when the actuator is driven, the power transmission mechanism causing the tilt frame to tilt by an angle corresponding to a difference of a number of teeth between the external gear and the internal gear in a case where the external gear rotates one turn along the inner periphery of the internal gear, the tilt frame being displaced in the direction to approach and separate from the support axis when the meshed position between the external gear and the internal gear moves along the inner periphery of the internal gear.
10. The seat reclining apparatus according to claim 2 , wherein the angle adjustment unit includes an internal gear formed at the support frame, an external gear formed at a tilt frame connected to the second frame and having fewer teeth compared to the internal gear, and an eccentric member integrally rotating with a drive shaft which is driven to rotate by the actuator, a portion of the internal gear engaging with a portion of the external gear, the external gear being rotatably mounted at an outer periphery of the eccentric member, and
the seat reclining apparatus further comprises a power transmission mechanism moving a meshed position between the external gear and the internal gear along an inner periphery of the internal gear by a rotational force of the eccentric member when the actuator is driven, the power transmission mechanism causing the tilt frame to tilt by an angle corresponding to a difference of a number of teeth between the external gear and the internal gear in a case where the external gear rotates one turn along the inner periphery of the internal gear, the tilt frame being displaced in the direction to approach and separate from the support axis when the meshed position between the external gear and the internal gear moves along the inner periphery of the internal gear.
11. The seat reclining apparatus according to claim 3 , wherein the angle adjustment unit includes an internal gear formed at the support frame, an external gear formed at a tilt frame connected to the second frame and having fewer teeth compared to the internal gear, and an eccentric member integrally rotating with a drive shaft which is driven to rotate by the actuator, a portion of the internal gear engaging with a portion of the external gear, the external gear being rotatably mounted at an outer periphery of the eccentric member, and
the seat reclining apparatus further comprises a power transmission mechanism moving a meshed position between the external gear and the internal gear along an inner periphery of the internal gear by a rotational force of the eccentric member when the actuator is driven, the power transmission mechanism causing the tilt frame to tilt by an angle corresponding to a difference of a number of teeth between the external gear and the internal gear in a case where the external gear rotates one turn along the inner periphery of the internal gear, the tilt frame being displaced in the direction to approach and separate from the support axis when the meshed position between the external gear and the internal gear moves along the inner periphery of the internal gear.
12. The seat reclining apparatus according to claim 4 , wherein the angle adjustment unit includes an internal gear formed at the support frame, an external gear formed at a tilt frame connected to the second frame and having fewer teeth compared to the internal gear, and an eccentric member integrally rotating with a drive shaft which is driven to rotate by the actuator, a portion of the internal gear engaging with a portion of the external gear, the external gear being rotatably mounted at an outer periphery of the eccentric member, and
the seat reclining apparatus further comprises a power transmission mechanism moving a meshed position between the external gear and the internal gear along an inner periphery of the internal gear by a rotational force of the eccentric member when the actuator is driven, the power transmission mechanism causing the tilt frame to tilt by an angle corresponding to a difference of a number of teeth between the external gear and the internal gear in a case where the external gear rotates one turn along the inner periphery of the internal gear, the tilt frame being displaced in the direction to approach and separate from the support axis when the meshed position between the external gear and the internal gear moves along the inner periphery of the internal gear.
13. The seat reclining apparatus according to claim 5 , wherein the angle adjustment unit includes an internal gear formed at the support frame, an external gear formed at a tilt frame connected to the second frame and having fewer teeth compared to the internal gear, and an eccentric member integrally rotating with a drive shaft which is driven to rotate by the actuator, a portion of the internal gear engaging with a portion of the external gear, the external gear being rotatably mounted at an outer periphery of the eccentric member, and
the seat reclining apparatus further comprises a power transmission mechanism moving a meshed position between the external gear and the internal gear along an inner periphery of the internal gear by a rotational force of the eccentric member when the actuator is driven, the power transmission mechanism causing the tilt frame to tilt by an angle corresponding to a difference of a number of teeth between the external gear and the internal gear in a case where the external gear rotates one turn along the inner periphery of the internal gear, the tilt frame being displaced in the direction to approach and separate from the support axis when the meshed position between the external gear and the internal gear moves along the inner periphery of the internal gear.
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2009085538A JP2010233840A (en) | 2009-03-31 | 2009-03-31 | Seat reclining device |
JP2009-085538 | 2009-03-31 |
Publications (1)
Publication Number | Publication Date |
---|---|
US20100244530A1 true US20100244530A1 (en) | 2010-09-30 |
Family
ID=42352674
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US12/730,356 Abandoned US20100244530A1 (en) | 2009-03-31 | 2010-03-24 | Seat reclining apparatus |
Country Status (4)
Country | Link |
---|---|
US (1) | US20100244530A1 (en) |
EP (1) | EP2236348A3 (en) |
JP (1) | JP2010233840A (en) |
CN (1) | CN101849748A (en) |
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US20120019041A1 (en) * | 2010-07-20 | 2012-01-26 | Faurecia Sieges D'automobile | Hinge Mechanism and Vehicle Seat Comprising Such a Mechanism |
US20120267932A1 (en) * | 2011-04-22 | 2012-10-25 | Aisin Seiki Kubushiki Kaisha | Seat reclining apparatus |
US20130207432A1 (en) * | 2009-08-12 | 2013-08-15 | Bruce A. Hiemstra | Modular Recline Mechanism And Sidemember For Rotary Recliner |
US20140319894A1 (en) * | 2011-07-20 | 2014-10-30 | C. Rob. Hammerstein Gmbh & Co. Kg | Adjusting device for a motor vehicle seat, comprising at least one stop |
US9010862B2 (en) * | 2012-10-23 | 2015-04-21 | Toyota Boshoku Kabushiki Kaisha | Seat frame structure |
US20150298586A1 (en) * | 2012-07-31 | 2015-10-22 | Johnson Controls Gmbh | Adjustable vehicle seat |
US10144313B2 (en) * | 2013-12-03 | 2018-12-04 | Aisin Seiki Kabushiki Kaisha | Deceleration device and seat drive device |
US20190016238A1 (en) * | 2017-07-11 | 2019-01-17 | Faurecia Sièges d'Automobile | Device for tilting the backrest of a vehicle seat and method for mounting such a tilting device |
US10266076B2 (en) * | 2016-08-17 | 2019-04-23 | Grammer Ag | Device for adjusting the inclination of a backrest |
US10399466B2 (en) * | 2017-12-26 | 2019-09-03 | Hyundai Dymos Incorporated | Seat recliner for vehicle |
US10870372B2 (en) * | 2016-10-04 | 2020-12-22 | Adient Luxembourg Holding S.Á R.L. | Vehicle seat, in particular motor vehicle seat |
US11065985B2 (en) | 2019-01-08 | 2021-07-20 | Toyota Boshoku Kabushiki Kaisha | Vehicle seat device |
US11142103B2 (en) * | 2019-01-17 | 2021-10-12 | Fisher & Company, Incorporated | Cross member for seat recliner assembly |
US11251680B2 (en) * | 2016-11-17 | 2022-02-15 | Shiroki Corporation | Deceleration device |
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DE102012014897A1 (en) * | 2012-01-25 | 2013-07-25 | GM Global Technology Operations LLC (n. d. Gesetzen des Staates Delaware) | Adjuster i.e. discontinuous adjuster, for adjusting backrest position of seat of motor vehicle e.g. passenger car, has locking devices actuatable over common actuator device and switched in series with actuator device |
CN102641189B (en) * | 2012-05-09 | 2014-03-12 | 合肥工业大学 | Easily-adjusted wheel chair |
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KR101598722B1 (en) * | 2014-12-30 | 2016-02-29 | 주식회사다스 | Seat-back folding device of work-in seat for vehicle |
JP6750471B2 (en) * | 2016-11-21 | 2020-09-02 | トヨタ紡織株式会社 | Vehicle seat |
JP2018118531A (en) * | 2017-01-23 | 2018-08-02 | トヨタ紡織株式会社 | Seat for vehicle |
CN113507864B (en) * | 2019-01-18 | 2024-02-02 | 富洛克公司 | Tilt lock device |
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Cited By (20)
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US20130207432A1 (en) * | 2009-08-12 | 2013-08-15 | Bruce A. Hiemstra | Modular Recline Mechanism And Sidemember For Rotary Recliner |
US9079515B2 (en) * | 2009-08-12 | 2015-07-14 | Johnson Controls Technology Company | Modular recline mechanism and sidemember for rotary recliner |
US8672407B2 (en) * | 2010-07-20 | 2014-03-18 | Faurecia Sièges d'Automobile | Hinge mechanism and vehicle seat comprising such a mechanism |
US20120019041A1 (en) * | 2010-07-20 | 2012-01-26 | Faurecia Sieges D'automobile | Hinge Mechanism and Vehicle Seat Comprising Such a Mechanism |
US20120267932A1 (en) * | 2011-04-22 | 2012-10-25 | Aisin Seiki Kubushiki Kaisha | Seat reclining apparatus |
US8950811B2 (en) * | 2011-04-22 | 2015-02-10 | Aisin Seiki Kabushiki Kaisha | Seat reclining apparatus |
US9499071B2 (en) * | 2011-07-20 | 2016-11-22 | C. Rob. Hammerstein Gmbh & Co. Kg | Adjusting device for a motor vehicle seat, comprising at least one stop |
US20140319894A1 (en) * | 2011-07-20 | 2014-10-30 | C. Rob. Hammerstein Gmbh & Co. Kg | Adjusting device for a motor vehicle seat, comprising at least one stop |
US9555725B2 (en) * | 2012-07-31 | 2017-01-31 | Johnson Controls Gmbh | Adjustable vehicle seat |
US20150298586A1 (en) * | 2012-07-31 | 2015-10-22 | Johnson Controls Gmbh | Adjustable vehicle seat |
US9010862B2 (en) * | 2012-10-23 | 2015-04-21 | Toyota Boshoku Kabushiki Kaisha | Seat frame structure |
US10144313B2 (en) * | 2013-12-03 | 2018-12-04 | Aisin Seiki Kabushiki Kaisha | Deceleration device and seat drive device |
US10266076B2 (en) * | 2016-08-17 | 2019-04-23 | Grammer Ag | Device for adjusting the inclination of a backrest |
US10870372B2 (en) * | 2016-10-04 | 2020-12-22 | Adient Luxembourg Holding S.Á R.L. | Vehicle seat, in particular motor vehicle seat |
US11251680B2 (en) * | 2016-11-17 | 2022-02-15 | Shiroki Corporation | Deceleration device |
US20190016238A1 (en) * | 2017-07-11 | 2019-01-17 | Faurecia Sièges d'Automobile | Device for tilting the backrest of a vehicle seat and method for mounting such a tilting device |
US10661686B2 (en) * | 2017-07-11 | 2020-05-26 | Faurecia Sieges D'automobile | Device for tilting the backrest of a vehicle seat and method for mounting such a tilting device |
US10399466B2 (en) * | 2017-12-26 | 2019-09-03 | Hyundai Dymos Incorporated | Seat recliner for vehicle |
US11065985B2 (en) | 2019-01-08 | 2021-07-20 | Toyota Boshoku Kabushiki Kaisha | Vehicle seat device |
US11142103B2 (en) * | 2019-01-17 | 2021-10-12 | Fisher & Company, Incorporated | Cross member for seat recliner assembly |
Also Published As
Publication number | Publication date |
---|---|
EP2236348A2 (en) | 2010-10-06 |
JP2010233840A (en) | 2010-10-21 |
CN101849748A (en) | 2010-10-06 |
EP2236348A3 (en) | 2011-03-23 |
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Legal Events
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AS | Assignment |
Owner name: AISIN SEIKI KABUSHIKI KAISHA, JAPAN Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:KITANO, TAKASHI;WATARIGUCHI, MITSUTOSHI;MORIMOTO, HIROKI;REEL/FRAME:024130/0090 Effective date: 20100318 |
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