SEAT ADJUSTING APPARATUS FOR VEHICLE
A seat adjusting apparatus includes: a first clutch mechanism; a second clutch mechanism; and a return member having a contact portion and a second engagement portion. The contact portion is configured to come in contact with a roller and is positioned in a wedge-shaped space. The contact portion is located at the side of an area, where a distance between a cam surface of an input side member of a first clutch mechanism and an inner peripheral surface of a control member is reduced. The second engagement portion is engaged in a circumferential direction with a first engagement portion provided at the input side member so that the return member rotates integrally with the input side member.
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This application is based on and claims priority under 35 U.S.C. § 119 to Japanese Patent Applications No. 2005-363956, filed on Dec. 16, 2005, No. 2005-377509, filed on Dec. 28, 2005, the entire content of which is incorporated herein by reference.
FIELD OF THE INVENTIONThe present invention relates to a seat adjusting apparatus for a vehicle, which adjusts a height of a seat cushion. More specifically, the present invention pertains to a clutch mechanism of a seat adjusting apparatus for a vehicle.
BACKGROUNDConventionally known are seat adjusting apparatuses for vehicles, which adjust the height of a seat cushion. In such seat adjusting apparatus, the height of the seat cushion is adjustable upon an operation of an operating lever in cases where an occupant is seated on the seat.
For example, according to a seat adjusting apparatus for a vehicle disclosed in JP2003-93187A (
In the first clutch mechanism, rollers are arranged in a wedge-shaped space defined between a cam surface provided at the input side member connected to the operating lever and an cylindrical surface of the control member. The control member rotates with the rollers engaged in response to rotation of the input side member. When the operating lever is released from being operated, the input side member is returns to the original neutral position.
However, according to the above-described structure, if the rollers rotate slowly relative to the rotation of the input side member in a situation where the input side member returns, the rollers arranged in the wedge-shaped space wedge-shaped space are occasionally trapped, i.e., engaged, between the cam surface and the cylindrical surface. In order to prevent a rotational error due to such engagement, a play is provided for the rollers in the wedge-shaped space. However, such play causes deterioration in an operation feeling due to a delayed movement of the rollers relative to the operation of the operating lever.
The present invention has been made in view of the above circumstances and provides a seat adjusting apparatus for a vehicle in which an operational performance of the operating member at the neutral position is enhanced.
SUMMARY OF THE INVENTIONAccording to an aspect of the present invention, a seat adjusting apparatus for a vehicle having a seat lifted up and down in response to a rotation of an output shaft following an operation of an operating lever, includes: a first clutch mechanism and a second clutch mechanism. The first clutch mechanism is connected to the operating lever and includes: an input side member connected to the operating member and having a cam surface and a first engagement portion; a control member having an inner peripheral surface facing the cam surface in a radial direction, a wedge-shaped space being defined between the inner peripheral surface and the cam surface; and at least one roller arranged in the wedge-shaped space. In the first clutch mechanism, operation force of the operating member is transmitted to the control member when the operating member is operated, and force transmission between the input side member and the control member is discontinued when the operating member returns to an original position. The second clutch mechanism includes: a static member housing the output shaft to be rotatable. In the second clutch mechanism, operation force of the operating member is transmitted to the output shaft from the control member when the operating member is operated, and the control member is engaged with the static member when the operating member is not operated so that the output shaft is locked not to rotate. The seat adjusting apparatus further includes a return member having a contact portion and a second engagement portion. The contact portion is configured to come in contact with the roller and is positioned in the wedge-shaped space. The contact portion is located at a side of an area, where a distance between the cam surface and the inner peripheral surface is more reduced than that of an area where the roller is located. The second engagement portion is engaged in a circumferential direction with the first engagement so that the return member rotates integrally with the input side member.
BRIEF DESCRIPTION OF THE DRAWINGS
An embodiment of the present invention is described below with reference to the attached drawings.
As illustrated in
The lower rails 2a and 2b are mounted with the upper rails 4a and 4b slidable over the lower rails 2a and 2b. The upper rails 4a and 4b support base frames 5a and 5b of the seat cushion 1a to be lifted up and down, respectively.
Lifter links 6a and 7a are supported at front and rear ends of the upper rail 4a so as to pivot about lower ends, respectively. The lifter links 6a and 7a are further connected to front and rear ends of the base frame 5a so as to pivot about upper ends, respectively. Likewise, lifter links 6b and 7b are supported at front and rear ends of the upper rail 4b so as to pivot about lower ends, respectively. The lifter links 6b and 7b are further connected to front and rear ends of the base frame 5b so as to pivot about upper ends, respectively. The joining point between the lifter link 7a and the base frame 5a is connected to the joining point between the lifter link 7b and the base frame 5b via an approximately cylindrical torque rod 8. Therefore, the base frames 5a and 5b are interlocked with each other to be lifted up and down.
The base frame 5b is equipped with a clutch mechanism 11 configuring the seat adjusting apparatus 3. An operating lever 12, which serves as an operating member, is attached to the clutch mechanism 11. A pinion gear 13 is mounted at an output shaft of the clutch mechanism 11. The pinion gear 13 rotates in response to operation of the operating lever 12. A sector gear 14 is supported at the base frame 5b behind the clutch mechanism 11 so as to rotate about its lower base end. The sector gear 14 is formed, at a distal end, with teeth 14a engaged with the pinion gear 13. The sector gear 14 is hence rotated in response to rotation of the pinion gear 13. An upper base end of the sector gear 14 is connected to an upper end of the lifter link 7b via the driving link 15 in a manner that the driving link 15 allows the sector gear 14 and the lifter link 7b to pivotably rotate. Therefore, once the sector gear 14 is pivoted, the lifter link 7b is pivoted via the driving link 15 and the litter link 7a is pivoted via the torque rod 8, wherein the base frames 5a and 5b are interlocked with each other to be lifted up or down.
Described below is a detailed structure of the clutch mechanism 11. As illustrated in
The output shaft 22 is integrally formed with a rotor cam 23 at the side of the operating lever 12 of the base frame 5b. The output shaft 22 is further formed integrally with the pinion gear 13 at an opposite side to the operating lever 12 of the base frame 5b. The rotor cam 23 exhibits an approximately hexagonal shape having an outer surface as a cam surface 23a and grooves 23b each defined at an intermediate of the corresponding edge of the hexagonal surface. According to the embodiment of the present invention, the rotor cam 23 and the pinion gear 13 are each formed integrally with the output shaft 22. However, the rotor cam 23 and the pinion gear 13 can be each separated from the output shaft 22 and can rotate integrally therewith.
Further, the output shaft 22 supports an input side member 24 to be freely rotatable, which input side member 24 is attached with the operating lever 12. As illustrated in
As is apparent from
Further, as illustrated in
The control member 32 is idly fitted at the radially outward side of the return member 31. The control member 32 includes an annular shaped outer race 32a, first engagement portions 32b and second engagement portions 32c. The first and second engagement portions 32b and 32c protrude along the axial direction from the outer race 32a to the opposite side to the operating lever 12 and are arranged in turn along the circumferential direction. The outer race 32a is positioned at the radially outward side of the contact portions 31b of the return member 31. A diameter of the outer peripheral surface of the outer race 32a is approximately identical to the diameter of the inner circumferential surface of the reduced diameter potion 21e of the case 21. Each first engagement portion 32b is fitted with a predetermined looseness into the corresponding groove 23b of the rotor cam 23. Each second engagement portion 32c is formed into an approximately L-shaped structure having a stepped portion 32e extending radially outwardly from the outer race 32a. A portion of each second engagement portion 32c, which extends axially, is arranged to be radially more outward than the first engagement portions 32b.
As illustrated in
As illustrated in
As is apparent from
As is obvious from
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As illustrated in
The input side member 24 is formed with a hook portion 26b, which is engageable with the first torsion spring 37 and serves as a first engagement portion, and protrusions 26c which come in contact with the engagement portions 21g of the case 21 in the circumferential direction. As illustrated in
The return member 31 is formed with a hook portion 31c which is engaged with the second torsion spring 38 and serves as a second engagement portion. As illustrated in
As illustrated in
Further, as illustrated in
According to the embodiment of the present invention, as illustrated in
Further, as illustrated in
The auxiliary frame 16 is formed with a through hole to be a first bearing 17, while the base frame 5b is formed with a through hole to be a second bearing 18 arranged to be coaxial with the first bearing 17. The second bearing 18 possesses a diameter larger than the one of the first bearing 17.
The output shaft 22 is supported, at its axially intermediate portion, by the second bearing 18 so as to be rotatable. The output shaft 22 is supported, at its distal end, by the first bearing 17 so as to be rotatable. The teeth 14a of the sector gear 14 are gear-meshed with the pinion gear 13 between the auxiliary frame 16 and the base frame 5b.
As illustrated in
Described below is an operation of the seat adjusting apparatus for a vehicle provided with the clutch apparatus 11 described above. As illustrated in
The inner race 25 illustrated in
Once the control member 32 rotates, the first engagement portions 32b of the control member 32 come in contact with side surfaces of the corresponding fitting grooves 23b of the rotor cam 23, wherein the rotor cam 23 is rotated in the clockwise direction in
Once the operating lever 12 is released from being operated, the output shaft 22 rotates counterclockwise in
Upon the operating lever 12 is released from being operated as described above, the return member 31 and the input side member 24 are biased by the first torsion spring 37 and the second torsion spring 38 to rotate back to the neutral positions. Here, the first rollers 33 rotate, by the contact portions 31b of the return member 31, in the same rotational direction as the return member 31 and the input side member 24, wherein the first rollers 33 are not locked or engaged and are movable. Therefore, the first rollers 33 are not restrained from returning to the neutral position. That is, in the first clutch mechanism 41, when the operating lever 12 returns to the original position thereof, torque transmitting between the input side member 24 and the control member 32 is cut off.
According to the embodiment of the present invention, the input side member 24 and the return member 31 rotate integrally with the through bores 26d being fitted with the projections 31d. Therefore, when the input side member 24 goes back to the original neutral position, the first rollers 33 are forced to rotate by the contact portions 31b in the wedge-shaped space between the cam surface 25a of the input side member 24 and the inner circumferential surface 32d of the control member 32. Here, the contact portions 31b are positioned at the sides where a distance between the cam surface 25a and the inner circumferential surface 32d is gradually reduced, that is to say, the contact portions 31b is located at a side of an area where a distance between the cam surface 25a and the inner peripheral surface 32d is more reduced than that of an area where the roller 33 is located. Therefore, even if a play does not exist in the wedge-shaped space defined in the first clutch mechanism 41, it is possible to prevent an event that the input side member 24 can not rotate by the locking or the engagement of the first rollers 33 at the wedge-shaped space when the input side member 24 goes back to the original neutral position by the release operation of the operating lever 12.
Especially, according to the embodiment of the present invention, in the case where the second torsion spring 38, which biases the return member 31 toward the original neutral position upon rotation of the return member 31, is provided, if the return member 31 is not structured so as to rotate integrally with the input side member 24, the return member 31 is biased to the neutral position by the second torsion spring 38, wherein the first rollers 33 are easily engaged in the wedge-shaped space. According to the embodiment of the present invention, the return member 31 is engaged with the input side member 24 and rotates integrally in the circumferential direction so that the first rollers 33 can be prevented from being engaged.
Further, the leaf spring 43 biases the hook portion 31c of the return member 31 towards the hook portion 26b of the input side member 24. Therefore, when the return member 31 returns to the neutral position, the return member 31 is applied with biasing force of the leaf spring 43 towards the input side member.
When the operating lever 12, which has been operated to lift up the seat 1, rotates to the neutral position, the clutch apparatus 11 operates in the same manner as the case where the operating lever 12 is released from being operated. Therefore, the rotation of the operating lever 12 is not limited. Further, when the operating lever 12 is operated to rotate in a direction for lifting down the seat 1, the clutch apparatus 11 rotates in an opposite direction and functions in the same manner. Therefore, the operation of the clutch apparatus 11 for the case in which the operating lever 12 is operated to rotate in the direction for lifting down the seat 1 will be omitted herein.
The following effects are obtained according to the embodiment of the present invention.
(1) The return member 31 rotates integrally with the input side member 24. Therefore, when the input side member 24 rotates and returns to the original neutral position in response to releasing of the operating lever 12 from an operated state, the first rollers 33 rotate with the contact portions 31b arranged at the sides, where the distance between the cam surface 25a and the inner circumferential surface 32d is narrowed, in each wedge-shaped space. As described above, the first rollers 33 are forced to move in response to rotation of the input side member 24, wherein it is possible to prevent an event that the input side member 24 can not rotate by the locking or the engagement of the first rollers 33 at the wedge-shaped space when the input side member 24 goes back to the original neutral position by the release operation of the operating lever 12. Therefore, it is possible to reduce an amount of play in each wedge-shaped space and to improve an operation performance of the operating lever 12 in the neutral position.
(2)
Provided is the leaf spring 34 which biases the return member 31 towards the input side member 24. Therefore, when the operating lever 12 is returned to the original neutral position after the rotation of the input side member 24 and the return member 31 in response to an operation of the operating lever 12, the return member 31 is biased toward the input side member 24 and rotates integrally with the input side member 24.
Conventionally, there is a seat for a vehicle provided with a seat adjusting apparatus, which adjusts the height or the surface level of a seat cushion. In such seat adjusting apparatus for a vehicle, the height of the seat cushion can be adjusted in a case where an occupant is seated on the seat.
The seat adjusting apparatus outputs torque in a normal direction or a reverse direction in response to an operation of an operating lever and adjusts the height of the seat cushion. Further, the seat adjusting apparatus includes a first clutch and a second clutch which retains the seat cushion at the appropriate height or position in a state where the operating lever has been released.
Once an operation force is applied to the operating lever, the operation force is transmitted to an output shaft via the first and second clutches. The second clutch prohibits the output shaft from rotating when the operating lever is not driven to operate. The seat adjusting apparatus further includes: a torsion spring returning the input side member connected to the operating lever when the operating lever is not inputted with an operation force; and a stopper restraining a rotational range of the input side member when the operating lever is operated.
Therefore, an outer race of the second clutch mechanism includes a flange serving as a stopper for restraining a rotation of the input side member and an engagement portion engaged with a torsion spring, as disclosed in JP2003-93187A (
However, the flange is formed by incising a flat portion of the outer race, which may deteriorate a mechanical rigidity of the outer race. This may require a process for working the incised portion. Further, because the flange is formed by being the incised portion, which limits the height of the flange and an axial height. In such circumstances, the torsion spring, which has a diameter different from the one of the outer race, is require to be located at the same axial position coaxially with the outer race. Therefore, it is necessary to increase the diameter of the outer race for the purpose of generating a predetermined amount of spring torque. This however causes upsizing of the apparatus.
The present invention has been made in view of the above circumstances and provides a seat adjusting apparatus downsized and formed with a simple structure and downsized.
(1) According to the embodiment of the present invention, the hook portion 21b extends axially from the reduced diameter portion 21e housing the first clutch mechanism 41 and the second clutch mechanism 42. Therefore, there is no need to apply a notching process or a bending process and so on so that the case 21 can be simply structured.
(2) The hook portion 21b, which is engaged with the first torsion spring 37 and the second torsion spring 38, extends axially from the reduced diameter portion 21e. Therefore, the axial length of the hook portion 21b is not limited and is formed in a way that the first and second torsion springs 37 and 38 are engaged appropriate points of the hook portion 21b respectively. This prevents upsizing of the apparatus in the radial direction and enables to downsize the apparatus.
(3) The engagement portion 21g, which comes in contact with the protrusion 26c of the input side member 24 and restrains rotation of the input side member 24, extends in the axial direction from the reduced diameter portion 21e. Therefore, there is no need to apply additional processes to the reduced diameter portion 21e, such as a notching process, a bending process or the like, and the case 21 is simply structured.
(4) The first engagement portion 21h, which is engaged with the first torsion spring 37, and the second engagement portion 21i, which is engaged with the second torsion spring 38, are formed continuously in the axial direction. Therefore, because the first and second torsion springs 37 and 38 can possess any diameters respectively, a radial directional size can be reduced by designing the first and second torsion springs 37 and 38 having the same diameter, which downsizes the apparatus.
(5) The first engagement portion 21h, which is engaged with the first torsion spring 37, and the second engagement portion 21i, which is engaged with the second torsion spring 38, are arranged at the same position in the circumferential direction. Therefore, a member (the hook portion 21b) can be shared by the first torsion spring 37 and the second torsion spring 38.
The embodiment of the present invention is not limited to the above and can be modified as follows.
According to the embodiment of the present invention, the return member 31 is engaged with the input side member 24 in the circumferential direction and rotate integrally with the projections 31d of the return member 31 fitted into the through bores 26d of the input side member 24 in the axial direction. However, the return member 31 can be engaged with the input side member 24 in another manner. For example, the input side member 24 can be provided with a projection as the first engagement portion, while the return member 31 can be provided with a recess as the second engagement portion. The input side member 24 and the return member 31 can rotate integrally with each other with the recess engaged with the projection.
According to the embodiment, provided is the leaf spring 43 serving as the biasing member biasing the return member 31 towards the input side member 31. More particularly, the leaf spring 43 biases the hook portion 31c of the return member 31 toward the hook portion 26b of the input side member 24. However, in substitution for the leaf spring 43, an elastic member such as a rubber can be disposed in a circumferential directional clearance between each through bore 26d of the input side member 24 and the corresponding projection 31d of the return member 31.
According to the embodiment, the case 21 of the clutch apparatus 11 is directly secured to the base frame 5b. However, the case 21 can be secured to a base supporting the output shaft 22 so as to unitize the clutch apparatus.
According to the embodiment, the seat cushion 1a is biased by the spiral spring 39 so as to be lifted up. However, the seat cushion 1a can be biases by another elastic member such as a torsion bar.
According to the embodiment, the cylindrical portion housing the first clutch mechanism 41 and the second clutch mechanism 42 includes the reduced diameter portion 21e and the enlarged diameter portion 21f. However, the shape of the cylindrical portion is not limited to the above. For example, a portion housing the first clutch mechanism can possess a diameter approximately identical to the one of a portion housing the second clutch mechanism.
As described above, the return member rotates integrally with the input side member. When the input side member rotates and returns to the neutral position when the operating member is driven to operate, the contact portion, which is located in the wedge-shaped space at the side of an area, where a distance between the cam surface and the inner peripheral surface is reduced rotates with the roller. Therefore, the rotor is forced to move in response to rotation of the input side member and the rotor is trapped, wherein a rotational error is avoided. Accordingly, a play in the wedge-shaped space can be reduced, and a user can obtain an appropriate operating feeling when operating the operating member, wherein it is possible to enhance an operability of the operating member at the neutral position.
It is preferable that the seat adjusting apparatus includes the biasing member biasing the return member towards the input side member. In this case, when the input side member is returned to the original neutral position after the input side member and the return member rotates in response to an operation of the operating member, the return member is biased toward the input side member so that the return member rotates integrally with the input side member.
According to the seat adjusting apparatus for a vehicle, it is possible to enhance an operability of the operating member at the neutral position.
The principles, of the 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 embodiment disclosed. Further, the embodiment 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 that fall within the spirit and scope of the present invention as defined in the claims, be embraced thereby.
Claims
1. A seat adjusting apparatus for a vehicle having a seat lied up and down in response to a rotation of an output shaft following an operation of an operating member, comprising:
- a first clutch mechanism connected to the operating member and including: an input side member connected to the operating member and having a cam surface and a first engagement portion; a control member having an inner peripheral surface facing the cam surface in a radial direction, a wedge-shaped space being defined between the inner peripheral surface and the cam surface; and at least one roller arranged in the wedge-shaped space, wherein operation force of the operating member is transmitted to the control member when the operating member is operated, and force transmission between the input side member and the control member is discontinued when the operating member returns to an original position,
- a second clutch mechanism including: a static member housing the output shaft to be rotatable; wherein operation force of the operating member is transmitted to the output shaft from the control member when the operating member is operated, and the control member is engaged with the static member when the operating member is not operated so that the output shaft is locked not to rotate,
- a return member having a contact portion and a second engagement portion, the contact portion configured to come in contact with the roller and positioned in the wedge-shaped space, the contact portion being located at a side of an area, where a distance between the cam surface and the inner peripheral surface is more reduced than that of an area where the roller is located, the second engagement portion engaged in a circumferential direction with the first engagement portion so that the return member rotates integrally with the input side member.
2. A seat adjusting apparatus for a vehicle according to claim 1, further comprising:
- a biasing member biasing the return member towards the input side member.
3. A seat adjusting apparatus according to claim 1, further comprising:
- an elastic member configured to store the operation force when the operating member is operated and to return the input side member to a neutral position by an elastic force based on the operation force stored therein when the operating member is not operated.
4. A seat adjusting apparatus according to claim 3, wherein the static member includes a cylindrical portion housing the first clutch mechanism and the second clutch mechanism and the elastic member engagement portion extending axially from the cylindrical portion and engaged with the elastic member.
5. A seat adjusting apparatus for a vehicle according to claim 1, wherein the control member is arranged at a radially outward side of the input side member and the static member is arranged at a radially outward side of the control member.
6. A seat adjusting apparatus for a vehicle according to claim 1, wherein the control member is arranged at a radially outward side of the input side member, the static member is arranged at a radially outward side of the control member, the second clutch mechanism prohibits a rotation of the output shaft against the static member when the operating member is not operated, the seat adjusting apparatus further comprising:
- an elastic member configured to store the operation force when the operating member is operated and to return the input side member to a neutral position by an elastic force based on the operation force stored therein when the operating member is not operated; and
- the static member including: a cylindrical portion housing the first clutch mechanism and the second clutch mechanism and an elastic member engagement portion extending axially from the cylindrical portion and engaged with the elastic member.
7. A seat adjusting apparatus according to claim 6, wherein the static member includes an input side member engagement portion extending axially from the cylindrical portion, and the input side member includes a projection coming in contact with the input side member engagement portion in the circumferential direction so that a rotational range of the input side member is restrained.
8. A seat adjusting apparatus according to claim 6, ether comprising:
- the roller including a plurality of rollers transmitting the operational force of the operating member from the cam surface of the input side member to the control member,
- the return member holding the rollers and moving the rollers with the input side member in a circumferential direction when the input side member returns to a neutral position;
- the elastic member including:
- a first elastic member for returning the input side member to the neutral position;
- a second elastic member for returning the holding member to a neutral position; and
- the elastic member engagement portion including: a first elastic member engagement portion axially extending from the cylindrical portion and engaged with the first elastic member; and a second elastic member engagement portion formed axially continuously at the first elastic member engagement portion and engaged with the second elastic member.
9. A seat adjusting apparatus according to claim 7, further comprising:
- the roller including a plurality of rollers transmitting the operational force of the operating member from the cam surface of the input side member to the control member,
- the return member holding the rollers and moving the rollers with the input side member in a circumferential direction when the input side member returns to a neutral position;
- the elastic member including:
- a first elastic member for returning the input side member to the neutral position;
- a second elastic member for returning the holding member to a neutral position; and
- the elastic member engagement portion including: a first elastic member engagement portion axially extending from the cylindrical portion and engaged with the first elastic member; and a second elastic member engagement portion formed axially continuously at the first elastic member engagement portion and engaged with the second elastic member.
10. A seat adjusting apparatus according to claim 8, wherein the first elastic member engagement portion and the second elastic member engagement portion are arranged at the same position in the circumferential direction.
11. A seat adjusting apparatus according to claim 9, wherein the first elastic member engagement portion and the second elastic member engagement portion are arranged at the same position in the circumferential direction.
Type: Application
Filed: Dec 14, 2006
Publication Date: Jun 21, 2007
Applicant: AISIN SEIKI KABUSHIKI KAISHA (Kariya-shi)
Inventors: Yukifumi YAMADA (Toyota-shi), Yasuhiro Kojima (Kariya-shi)
Application Number: 11/610,630
International Classification: F16D 67/00 (20060101);