Vehicle seat

Abstract

To obtain a vehicle seat which can inhibit unintentional disengagement of engagement teeth in each gear member forming a lock mechanism.SOLUTION: A vehicle seat 10 includes: a lock mechanism 70 which locks a linkage 60 by engagement between first engagement teeth 74B of a first gear member 74 and second engagement teeth 76B of a second gear member 76; and a biasing mechanism 90 which biases the second engagement teeth 76B in an engagement direction relative to the first engagement teeth 74B. The biasing mechanism 90 has: a cam holding member 80 which moves a cam 82 in a pressing direction and a pressing release direction relative to the contact surface 76D of the second gear member 76; a biasing member 88 which biases the cam holding member 80 so that the cam 82 presses the contact surface 76D; and an operation member 78 which moves the cam holding member 80 so as to prevent the cam 82 from pressing the contact surface 76D. The operation member 78 has an engagement part 78B which engages with the engaged part 80F of the cam holding member 80 only when the cam holding member 80 is biased by the biasing member 88.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to a vehicle seat.

Background Art

[0002] A vehicle seat including an air suspension mechanism that changes the height of a seat cushion by supplying air to or discharging air from an air chamber disposed below the vehicle seat when a switch is operated by an occupant, and a lock mechanism that is displaceable to a lock position for locking the height position of the seat cushion and an unlock position for releasing the lock has been conventionally known (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The vehicle seat as described above has link mechanisms on both the left and right sides below the seat cushion for supporting the seat cushion so as to be movable up and down. The link mechanisms are configured such that their height positions are locked and unlocked by a lock mechanism. That is, the link mechanisms are configured to be locked by the engagement of the engaging teeth of a gear member provided on one link arm and the engaging teeth of a gear member provided on the other link arm, and to be unlocked by the release of the engagement of those engaging teeth.

[0005] By the way, when a passenger gets into the vehicle, the seat cushion may be greatly swung in the left-right direction (seat width direction) by the passenger. That is, a load in the seat width direction may be input to the link mechanism provided on the lower side of the seat cushion. In that case, one link arm constituting the link mechanism may tilt in a direction away from the other link arm, and there is a concern that the engagement teeth of each gear member constituting the lock mechanism may unintentionally disengage.

[0006] Therefore, an object of the present invention is to obtain a vehicle seat capable of suppressing unintentional disengagement of the engagement teeth of each gear member constituting the lock mechanism.

Means for Solving the Problems

[0007] In order to achieve the above object, a vehicle seat according to a first aspect of the present invention has a first link arm and a second link arm rotatably connected at a central portion in the longitudinal direction, and is provided on the outer side in the seat width direction on the lower side of the seat cushion in the seat width direction. A link mechanism, a first engagement tooth formed on an end face of a first gear member provided on the first link arm, and a second engagement tooth formed on an end face of a second gear member provided on the second link arm. A lock mechanism that locks the link mechanism by meshing and unlocks the link mechanism by releasing the meshing between the first engagement tooth and the second engagement tooth, and an urging mechanism that urges the second engagement tooth in the meshing direction with respect to the first engagement tooth. The biasing mechanism includes a cam configured to be able to contact an abutting surface that is an end surface of the second gear member on the side opposite to the second engagement tooth, a cam holding member that holds the cam and moves the cam in a pressing direction and a pressing release direction with respect to the abutting surface, and a biasing member that biases the cam holding member so that the cam presses the abutting surface. And an operating member that moves the cam holding member against the biasing force of the biasing member so that the cam does not press the abutting surface. The operating member has a locking portion that locks to a locked portion formed on the cam holding member only when the cam holding member is biased by the biasing member so that the cam presses the abutting surface.

[0008] According to the invention of the first aspect, the actuating member has a locking portion that locks to a locked portion formed on the cam holding member only when the cam holding member is biased by the biasing member so that the cam presses the contact surface. Therefore, when the link mechanism is locked, even if a load is input in the seat width direction with respect to the link mechanism, the cam holding member, the cam, and the second gear member are suppressed from tilting with respect to the first gear member. Thereby, the meshing between the first engaging teeth and the second engaging teeth is suppressed from unintentionally coming off.

[0009] Further, the vehicle seat according to the second aspect of the present invention is the vehicle seat according to the first aspect, wherein the cam holding member is rotatably supported at the longitudinal center portion, the cam is held on one end portion side in the longitudinal direction of the cam holding member, the actuating member is configured to be able to press an end surface on the other end portion side in the longitudinal direction of the cam holding member, and the end surface is an inclined surface that inclines so as to approach the actuating member as it moves away from the rotation center of the cam holding member.

[0010] According to the invention of the second aspect, the cam is held on one end portion side in the longitudinal direction of the cam holding member that is rotatably supported at the longitudinal center portion, and the actuating member is configured to be able to press the end surface on the other end portion side in the longitudinal direction thereof. And the end surface is an inclined surface that inclines so as to approach the actuating member as it moves away from the rotation center of the cam holding member. Therefore, the actuating member can efficiently rotate the cam holding member, and as a result, the locking mechanism can be configured compactly.

[0011] Further, the vehicle seat according to the third aspect of the present invention is the vehicle seat according to the second aspect, wherein the locked portion is formed on the other end portion side in the longitudinal direction of the cam holding member.

[0012] According to the invention of the third aspect, the locked portion is formed on the other end side in the longitudinal direction of the cam holding member. Therefore, the pressing force (moment force) applied to the second gear member by the cam held on one end side in the longitudinal direction of the cam holding member is effectively maintained, and as a result, the meshing force between the first engaging teeth and the second engaging teeth is improved. Thus, even when a load acting in the seat width direction is input to the link mechanism, the cam holding member, the cam, and the second gear member are effectively suppressed from tilting with respect to the first gear member.

[0013] Further, the vehicle seat according to the fourth aspect of the present invention is the vehicle seat according to any one of the first to third aspects, wherein the cam holding member is configured to move the second gear member so that the second engaging teeth are separated from the first engaging teeth when the cam is moved against the biasing force of the biasing member by the operating member so as not to press the contact surface.

[0014] According to the invention of the fourth aspect, when the cam is moved against the biasing force of the biasing member by the operating member so as not to press the contact surface of the second gear member, the cam holding member moves the second gear member so that the second engaging teeth are separated from the first engaging teeth. Therefore, when the cam holding member does not move the second gear member so that the second engaging teeth are separated from the first engaging teeth at that time, the occurrence of unlocking failure when unlocking the lock mechanism is suppressed.

Effects of the Invention

[0015] As described above, according to the present invention, it is possible to suppress the unintended disengagement of the meshing of the engaging teeth in each gear member constituting the lock mechanism.

Brief Description of the Drawings

[0016]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Mode for Carrying Out the Invention

[0017] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. For convenience of explanation, in each figure, the arrow UP shown as appropriate is the upward direction of the vehicle seat, the arrow FR is the forward direction of the vehicle seat, and the arrow RH is the rightward direction of the vehicle seat. Also, in the following description, when the directions of up and down, front and back, and left and right are described without special mention, they indicate up and down, front and back, and left and right in the vehicle seat. Also, the left - right direction is synonymous with the seat width direction, and the view from the seat width direction is referred to as "side view".

[0018] As shown in FIG. 1, the vehicle seat 10 includes a seat body 12 and a seat support device 20. The seat body 12 includes a seat cushion 14 that forms a seating portion on which an occupant sits and supports the buttocks and thighs of the seated occupant, a seat back 16 that supports the back of the seated occupant, and a headrest 18 that supports the head of the seated occupant.

[0019] As shown in FIGS. 2 and 3, the seat support device 20 is disposed below the seat cushion 14. The seat support device 20 includes an upper frame 22 and a lower frame 24. The upper frame 22 and the lower frame 24 are arranged vertically. The upper frame 22 supports the seat body 12 from below, and the lower frame 24 is disposed below the upper frame 22 and fixed to the vehicle body (not shown).

[0020] The upper frame 22 is formed in a substantially rectangular frame shape in plan view, and includes a pair of left and right side members 26 and 28 arranged at intervals in the left-right direction, a front member 30 spanned between the front ends of the pair of left and right side members 26 and 28, and a rear member 32 spanned between the rear ends of the pair of left and right side members 26 and 28. A front pipe 33 is provided parallel to the front member 30 on the rear side of the front member 30, and a rear pipe 34 is provided parallel to the rear member 32 on the front side of the rear member 32.

[0021] The lower frame 24 is formed in a substantially rectangular frame shape in plan view, and includes a pair of left and right side members 36 and 38 arranged at intervals in the left-right direction, a front member 40 spanned between the front ends of the pair of left and right side members 36 and 38, and a rear pipe 42 spanned between the rear ends of the pair of left and right side members 36 and 38. A front pipe 43 is provided parallel to the front member 40 on the rear side of the front member 40.

[0022] Note that fixing plates 44 fixed to the vehicle body side are provided on the lower surfaces of the rear ends of the side members 36 and 38. An upper support plate 46 is spanned along the seat width direction between the side members 26 and 28 of the upper frame 22 on the front side of the rear pipe 34. A lower support plate 48 is spanned along the seat width direction between the side members 36 and 38 of the lower frame 24 on the front side of the rear pipe 42.

[0023] In addition, the seat support device 20 has an air suspension mechanism 50. The air suspension mechanism 50 includes an air spring 52 and a damper 54. The air spring 52 is disposed between the upper support plate 46 and the lower support plate 48 and is supported by the upper support plate 46 and the lower support plate 48.

[0024] Specifically described, the air spring 52 is formed in a substantially cylindrical shape with the vertical direction as the axial direction. The lower end portion of the air spring 52 is fixed to a substantially central portion in the longitudinal direction (left - right direction) of the lower support plate 48 of the lower frame 24. And the upper end portion of the air spring 52 is fixed to a substantially central portion in the longitudinal direction (left - right direction) of the upper support plate 46 of the upper frame 22.

[0025] Also, the air spring 52 is configured such that compressed air can be supplied from an air compressor (air supply source) which is a part of, for example, the air brake device of a vehicle. That is, when air is supplied to this air spring 52, it extends upward and moves the upper frame 22 upward, and when air is discharged, it contracts downward and moves the upper frame 22 downward.

[0026] In other words, this air spring 52 can adjust the height of the seating surface 14A (see FIG. 1) of the seat cushion 14 supported by the upper frame 22 by expanding and contracting in the vertical direction according to the amount of air supplied or discharged. Note that the amount of air in the air spring 52 is configured to be adjusted by a height control unit 51 (see FIG. 3).

[0027] As shown in FIG. 3, the damper 54 is, for example, an oil-type cylinder damper and is disposed on the left side within the seat support device 20 of the vehicle seat 10 (see FIG. 1). One end of the damper 54 is connected to the upper frame 22, and the other end of the damper 54 is connected to the lower frame 24. That is, the damper 54 connects between the upper frame 22 and the lower frame 24. By this damper 54, vibrations generated in the seat body 12 can be attenuated.

[0028] Also, as shown in FIG. 1, an operation unit 55 is provided at the lower right side of the vehicle seat 10. The operation unit 55 is provided with a height lever 56 for operating the air spring 52 and a damper lever 58 for operating the damper 54. The height lever 56 and the damper lever 58 are on the same axis (coaxial) and are configured to be rotatable separately.

[0029] Then, as shown in FIGS. 2 and 3, one ends of an air supply cable 56A and an exhaust cable 56B are connected to the height lever 56, and one end of a damper cable 58A is connected to the damper lever 58. Further, the air supply cable 56A, the exhaust cable 56B, and the damper cable 58A are routed so as to have a slack portion 57 and are fixed to the upper frame 22, the lower frame 24, etc. by a plurality of clips 59.

[0030] Also, as shown in FIGS. 2 to 4, the seat support device 20 has a link mechanism 60 that supports the upper frame 22 so as to be vertically movable (ascend and descend) with respect to the lower frame 24. The link mechanism 60 includes a pair of so-called X-links 62 on the left and right, and the right X-link 62 is shown in FIGS. 4 to 8. Each X-link 62 is configured to connect the upper frame 22 and the lower frame 24 so that the upper frame 22 can move up and down with respect to the lower frame 24.

[0031] As shown in FIG. 4, the X link 62 includes an outer link arm 64 as a first link arm disposed on the outer side in the sheet width direction, and an inner link arm 66 as a second link arm disposed on the inner side in the sheet width direction. The outer link arm 64 is inclined downward as it goes forward, and the inner link arm 66 is inclined upward as it goes forward. The outer link arm 64 and the inner link arm 66 are connected by a link shaft 68 (a fastener such as a bolt) as a shaft portion so as to be rotatable about the sheet width direction as an axial direction at the central portion in the longitudinal direction (front-rear direction).

[0032] Also, the front end portions of the left and right outer link arms 64 are connected in the left-right direction by the front pipe 43 of the lower frame 24, and the rear end portions of the left and right outer link arms 64 are connected in the left-right direction by the rear pipe 34 of the upper frame 22. The front end portions of the left and right inner link arms 66 are connected in the left-right direction by the front pipe 33 of the upper frame 22, and the rear end portions of the left and right inner link arms 66 are connected in the left-right direction by the rear pipe 42 of the lower frame 24.

[0033] Therefore, by the pair of left and right X links 62 rotating synchronously, the upper frame 22 is configured to move up and down along the vertical direction. That is, the outer link arm 64 and the inner link arm 66 rotate relatively in opposite directions about the link shaft 68 at the central portion in the longitudinal direction (front-rear direction), so that the upper frame 22 can move up and down with respect to the lower frame 24.

[0034] Specifically, when the inclination directions of the outer link arm 64 and the inner link arm 66 are displaced so as to approach the vertical direction (the X link 62 is raised upward), the upper frame 22 is displaced (raised) upward, and when the inclination directions of the outer link arm 64 and the inner link arm 66 are displaced so as to approach the front-rear direction (the X link 62 is folded downward), the upper frame 22 is displaced (lowered) downward.

[0035] Further, as shown in FIGS. 4 to 8, the link mechanism 60 has a lock mechanism 70 that locks and unlocks the rotation of the outer link arm 64 and the inner link arm 66. That is, this lock mechanism 70 is configured to be displaceable between a lock position that locks the height position (vertical position) of the seat cushion 14 and an unlock position that releases the lock.

[0036] The lock mechanism 70 includes a lock mechanism main body 72 supported by one of the pair of left and right X-links 62 and arranged along the one X-link 62, and an actuator (not shown) such as a motor that operates the lock mechanism main body 72. Note that the lock mechanism main body 72 in the present embodiment is supported by the right X-link 62 and is arranged on the front side with respect to the link shaft 68.

[0037] As shown in FIGS. 4 to 8, the lock mechanism main body 72 has a ratchet gear 74 as a first gear member supported by the outer link arm 64. Further, the lock mechanism main body 72 has a ball gear 76 as a second gear member supported by the inner link arm 66, a rotor 78 as an operating member, a cam bracket 80 as a cam holding member, and a cam 82 held by the cam bracket 80.

[0038] The lock mechanism main body 72 also has a retainer bracket 84 and a cover 86 that support the ball gear 76, the rotor 78, the cam bracket 80, and the cam 82. The lock mechanism main body 72 also has a tension coil spring 88 as a biasing member that biases the cam bracket 80 to one side. Note that the rotor 78, the cam bracket 80, the cam 82, and the tension coil spring 88 constitute a biasing mechanism 90 that biases the engaging tooth 76B, which will be described later, in the meshing direction with respect to the engaging tooth 74B, which will be described later.

[0039] The ratchet gear 74 is formed in a substantially "C"-shaped curved flat plate shape in side view, with the left-right direction being the thickness direction and the substantially up-down direction being the longitudinal direction. That is, the ratchet gear 74 has a gear body portion 74A whose rear end face facing the rear side and front end face facing the front side are each formed in an arc surface shape centered on the link shaft 68 of the X link 62 in side view.

[0040] A bolt insertion hole 74C is formed at the lower end portion of the gear body portion 74A, and the lower end portion thereof is fixed to the outer link arm 64 by a fastening tool 94 such as a bolt that penetrates the bolt insertion hole 74C. And a plurality of engaging teeth 74B as the first engaging teeth are formed on the front end face of the gear body portion 74A. Note that the plurality of engaging teeth 74B are formed at equal intervals along the front end face of the gear body portion 74A.

[0041] Also, an arc-shaped long hole 66A centered on the link shaft 68 of the X link 62 is formed in the inner link arm 66. And a bolt insertion hole 74C is formed at the upper end portion of the gear body portion 74A, and the upper end portion thereof is fixed to the outer link arm 64 by a fastening tool 94 that penetrates the bolt insertion hole 74C and the long hole 66A. Note that the dimension of this long hole 66A is set to a dimension that does not prevent the up-and-down movement of the X link 62. That is, within the up-and-down movement range of the X link 62, the fastening tool 94 inserted into the long hole 66A does not contact the longitudinal direction end faces of the long hole 66A.

[0042] The ball gear 76 is disposed on the front side with respect to the ratchet gear 74. The ball gear 76 is formed in a flat plate shape with the left-right direction being the thickness direction and the substantially up-down direction being the longitudinal direction in side view. A collar insertion hole 76A into which a collar 77 is inserted is formed at the upper end portion of the ball gear 76, and the upper end portion of the ball gear 76 is rotatably supported by a retainer bracket 84 and a cover 86 via the collar 77. Note that a fastening tool 94 for attaching the ball screw 76 is inserted into this collar 77 (see FIG. 5).

[0043] On the surface of the ball gear 76 facing the cover 86 side at the lower part, an engagement protrusion 76C formed in a columnar shape protrudes integrally toward the cover 86 side. Further, on the rear end surface of the ball gear 76 facing the rear side at the lower part, engagement teeth 76B as a plurality of second engagement teeth are formed. The plurality of engagement teeth 76B are formed at equal intervals along the rear end surface of the lower part of the ball gear 76, and are configured such that the engagement teeth 76B and the engagement teeth 74B mesh with each other. Further, the front end surface of the ball gear 76 facing the front side at the lower part (the end surface on the opposite side to the engagement teeth 76B) is a cam contact surface 76D as a contact surface with which the rear end portion of the cam 82 abuts (contacts).

[0044] The rotor 78 is formed in a flat plate shape that is substantially "L" - shaped in side view with the left - right direction being the thickness direction. At the upper end portion of this rotor 78, a shaft insertion hole 78A that is substantially "D" - shaped in side view into which a substantially columnar shaft 92 having the left - right direction as the axial direction is inserted is formed. And, the base end portion of the shaft 92 on the retainer bracket 84 side is a rotor engagement portion 92A that is substantially "D" - shaped in side view and is inserted into the shaft insertion hole 78A of the rotor 78, and the shape of the rotor engagement portion 92A corresponds to the inner peripheral surface of the shaft insertion hole 78A. Thereby, the rotor 78 and the shaft 92 are configured to be coupled so as not to be relatively rotatable.

[0045] Further, the tip portion of the shaft 92 on the cover 86 side is formed in a substantially "D" - shaped shape in side view and is an engagement portion 92B with which the actuator engages. Note that, by inserting the shaft 92 through the retainer bracket 84 and the cover 86, the rotor 78 is rotatably supported by the retainer bracket 84 and the cover 86.

[0046] Further, a push nut (not shown) is engaged with the base end portion of the shaft 92 protruding toward the inner link arm 66 side, so that the shaft 92 does not fall out from the retainer bracket 84. Further, on the surface of the rotor 78 facing the cover 86 side, an engagement protrusion 78B formed in a columnar shape protrudes integrally toward the cover 86 side.

[0047] The cam bracket 80 is provided between the rotor 78 and the ball gear 76. The cam bracket 80 is formed in a flat plate shape with the left - right direction being the thickness direction and the front - rear direction being the longitudinal direction in a side view. A collar insertion hole 80A into which a collar 85 as a shaft portion is inserted is formed at the center of the cam bracket 80 in the front - rear direction. The cam bracket 80 is rotatably supported by a retainer bracket 84 and a cover 86 via the collar 85 inserted into the collar insertion hole 80A. Note that a fastener 94 for attaching the cam bracket 80 etc. is inserted into this collar 85 (see Fig. 6).

[0048] A long - hole - shaped notch 80B with the vertical direction as the longitudinal direction is formed on the rear side (one - end side in the longitudinal direction) of the collar insertion hole 80A of the cam bracket 80. An engaging projection 76C of the ball gear 76 can be inserted into the inside of this notch 80B. Then, as the cam bracket 80 rotates and displaces, the engaging projection 76C is inserted into the inside of the notch 80B, and the ball gear 76 moves together with the cam bracket 80, so that the ball gear 76 is displaced from the ratchet gear 74 side to the side opposite to the ratchet gear 74 side (in the direction in which the engaging teeth 76B separate from the engaging teeth 74B).

[0049] Also, an engaging hole 80C into which an engaging projection 82B (described later) of the cam 82 is press - fitted is formed between the collar insertion hole 80A and the notch 80B of the cam bracket 80. The upper end surface on the front side (the other - end side in the longitudinal direction) of the collar insertion hole 80A of the cam bracket 80 is an inclined surface that inclines upward and forward in a side view (it inclines so as to approach the lower end surface of the rotor 78 as it moves away from the rotation center of the cam bracket 80), and this inclined surface serves as a rotor engaging surface 80D with which the lower end surface of the rotor 78 engages (presses). Also, a spring locking portion 80E that protrudes toward the cover 86 side is integrally formed at the front end portion of the cam bracket 80.

[0050] The cam 82 is disposed on the retainer bracket 84 side with respect to the cam bracket 80. The cam 82 is formed in a substantially teardrop-shaped flat plate shape in which the left-right direction is the thickness direction and the front-rear direction is the longitudinal direction in side view. A color insertion hole 82A into which a color 85 is inserted is formed at the front portion of the cam 82. And, from the surface of the rear portion of the cam 82 facing the cam bracket 80 side, an engagement protrusion 82B formed in a columnar shape protrudes integrally toward the cam bracket 80 side.

[0051] By press-fitting this engagement protrusion 82B into the engagement hole 80C of the cam bracket 80, the cam 82 is configured to be integrally coupled to the cam bracket 80 so as not to be relatively rotatable. That is, the cam 82 is held by the cam bracket 80 and is configured to be rotatably supported together with the cam bracket 80 via the color 85 inserted into the color insertion hole 80A of the retainer bracket 84 and the cover 86. And, the tapered rear end portion of this cam 82 is adapted to abut (contact) the cam contact surface 76D of the ball gear 76.

[0052] The retainer bracket 84 has a bracket main body portion 84A formed in a substantially rectangular flat plate shape in which the left-right direction is the thickness direction and the up-down direction is the longitudinal direction in side view, and a cover engagement portion 84B that bends and extends from the upper end portion of the bracket main body portion 84A toward the cover 86 side. Further, in the bracket main body portion 84A, two color insertion holes 84C into which colors 77 and 85 are respectively inserted, a shaft insertion hole 84D into which a shaft 92 is inserted, and a rivet insertion hole 84E into which a rivet 96 (to be described later) to be attached between the cover 86 is inserted are formed.

[0053] As shown in FIG. 5, the cover 86 as a cover member is formed in a substantially rectangular flat plate shape in which the left - right direction is the thickness direction and the up - down direction in side view is the longitudinal direction. The cover 86 has a cover main body portion 86A that covers most parts such as the ball gear 76, the rotor 78, and the cam bracket 80 from the inner side in the sheet width direction, and a spring locking portion 86B that bends and extends from the upper end portion of the cover main body portion 86A toward the side opposite to the retainer bracket 84.

[0054] And in the cover main body portion 86A, there are formed two collar insertion holes 86C into which collars 77 and 85 are respectively inserted, a shaft insertion hole 86D into which the shaft 92 is inserted, a rivet insertion hole 86E into which the rivet 96 is inserted, and an arc - shaped long hole 86F into which the engaging projection 78B formed on the rotor 78 is inserted. Note that the dimensions of this long hole 86F are set to dimensions that do not prevent the rotation of the rotor 78.

[0055] As shown in FIGS. 4 to 8, the tension coil spring 88 is bridged between the cam bracket 80 and the cover 86. That is, one end portion of the tension coil spring 88 is locked to the spring locking portion 80E of the cam bracket 80, and the other end portion of the tension coil spring 88 is locked to the spring locking portion 86B of the cover 86. Due to the biasing force of this tension coil spring 88, the rear end portion of the cam 82 abuts against the cam contact surface 76D of the ball gear 76 and presses the cam contact surface 76D, and the cam bracket 80 is constantly rotationally biased to one side (in the clockwise direction in the figure).

[0056] The actuator is configured to operate when energized so that an output portion (not shown) rotates. The engaging portion 92B of the shaft 92 is engaged with the output portion of the actuator. Thereby, the shaft 92 is configured to function as the output shaft of the actuator. That is, when the actuator operates, the shaft 92 rotates together with the rotor 78 in the clockwise direction in the figure, and the cam bracket 80 rotates in the counter - clockwise direction in the figure against the biasing force of the tension coil spring 88.

[0057] Therefore, next, the operation of the lock mechanism 70 will be described. In a normal state, the cam bracket 80 is located at the lock position (see FIG. 7). That is, due to the biasing force of the tension coil spring 88, the front end portion of the cam bracket 80 is pulled upward, and the rear end portion of the cam bracket 80 is biased downward (in the direction in which the cam 82 presses the cam contact surface 76D).

[0058] As a result, the rear end portion of the cam 82 presses the cam contact surface 76D of the ball gear 76 toward the rear side, so that the engaging teeth 76B of the ball gear 76 firmly mesh with the engaging teeth 74B of the ratchet gear 74. Thereby, the X-link 62 is locked. At this time, the lower end portion of the rotor 78 is separated from the rotor engaging surface 80D of the cam bracket 80 or is in a state of not applying a force to the rotor engaging surface 80D.

[0059] On the other hand, when adjusting the height of the seat cushion 14, the actuator operates and the shaft 92 rotates in the clockwise direction as shown in the figure. Then, the rotor 78 rotates in the clockwise direction as shown in the figure, and presses the rotor engaging surface 80D of the cam bracket 80 toward the front side. As a result, the cam bracket 80 rotates so that its front portion moves downward and its rear portion moves upward against the biasing force of the tension coil spring 88.

[0060] Then, the cam bracket 80 houses the engaging projection 76C of the ball gear 76 in its notch 80B, and moves the lower portion of the ball gear 76 forward through the engaging projection 76C. That is, the cam bracket 80 releases the pressing of the cam contact surface 76D of the ball gear 76 by the rear end portion of the cam 82 (while moving the cam 82 in the pressing release direction), and separates the engaging teeth 76B of the ball gear 76 from the engaging teeth 74B of the ratchet gear 74. As a result, the meshing of the engaging teeth 76B of the ball gear 76 with the engaging teeth 74B of the ratchet gear 74 is released, and the X-link 62 is unlocked (see FIG. 8).

[0061] Here, as shown in FIGS. 7 and 8, a hook 78C is integrally formed at the upper front end of the rotor 78 as a locking portion that forms a substantially "J" shape in a side view. And a notch 80F is formed at the front end (the other end in the longitudinal direction) of the cam bracket 80 as a portion to be locked to which the tip of the hook 78C is locked. This hook 78C is configured to be locked to the notch 80F only when the cam bracket 80 is biased by the tension coil spring 88 such that the cam 82 presses the cam contact surface 76D of the ball gear 76.

[0062] That is, the hook 78C is configured to be locked to the notch 80F by the biasing force of the tension coil spring 88, and when the actuator operates and the shaft 92 rotates in the clockwise direction shown in the figure and the rotor 78 rotates in the clockwise direction shown in the figure, the hook 78C is configured to be disengaged from the notch 80F. When the hook 78C is locked to the notch 80F, the cam bracket 80 is configured to be more firmly held in the locked position.

[0063] Next, the operation of the vehicle seat 10 according to the present embodiment configured as described above will be described.

[0064] First, the lock mechanism 170 according to the comparative example shown in FIG. 9 will be described. In this lock mechanism 170, except that the hook 78C and the notch 80F are not formed, it has the same configuration as the above lock mechanism 70. That is, the engagement teeth 176B of the ball gear 176 mesh with the engagement teeth 174B of the ratchet gear 174, and the X-link 162 constituting the link mechanism 160 is locked in the same manner as described above.

[0065] Here, for example, when a large-sized occupant gets into the vehicle, the seat cushion 14 may be greatly swung in the left-right direction (seat width direction) by the occupant. That is, a large load in the seat width direction may be input to the link mechanism 160 provided below the seat cushion 14.

[0066] In that case, the lower part of the inner link arm 166 of the X link 162 that constitutes the link mechanism 160 may tilt in a direction away from the outer link arm 164 (a direction in which the upper part of the inner link arm 166 approaches the outer link arm 164). As shown in FIG. 9, the cam bracket 180, the cam 182, and the ball gear 176 supported by the inner link arm 166 may shift (tilt) in the thickness direction from the ratchet gear 174 supported by the outer link arm 164.

[0067] That is, the engaging teeth 176B of the ball gear 176 may shift in the thickness direction with respect to the engaging teeth 174B of the ratchet gear 174. When a large load in the seat width direction is further input to the link mechanism 160 in a state where it has shifted in the thickness direction, the engaging teeth 176B of the ball gear 176 may unintentionally disengage from the engaging teeth 174B of the ratchet gear 174 (the meshing may be released).

[0068] On the other hand, in the lock mechanism 70 according to the present embodiment, a hook 78C and a notch 80F are formed. That is, this lock mechanism 70 has a hook 78C that locks to the notch 80F formed in the cam bracket 80 only when the cam bracket 80 is biased by the tension coil spring 88 so that the cam 82 presses the cam contact surface 76D.

[0069] Therefore, the cam bracket 80 is more firmly held in the locked position. When a load in the seat width direction is input to the X link 62 while the X link 62 that constitutes the link mechanism 60 is locked, tilting (shifting in their thickness direction) of the cam bracket 80, the cam 82, and the ball gear 76 with respect to the ratchet gear 74 is suppressed. Thereby, it is possible to suppress or prevent the engaging teeth 76B of the ball gear 76 from unintentionally disengaging from the engaging teeth 74B of the ratchet gear 74 (the meshing being released).

[0070] Moreover, since the notch portion 80F is formed at the front end portion (the other end portion in the longitudinal direction) of the cam bracket 80, the pressing force (moment force) of the cam 82 held at the rear portion (one end portion side in the longitudinal direction) of the cam bracket 80 against the cam contact surface 76D of the ball gear 76 is effectively maintained. As a result, the meshing force between the engaging teeth 74B of the ratchet gear 74 and the engaging teeth 76B of the ball gear 76 can be improved.

[0071] Therefore, even when a load acting in the seat width direction is input to the X-link 62 constituting the link mechanism 60, it is possible to more effectively suppress or prevent the cam bracket 80, the cam 82, and the ball gear 76 from tilting (shifting in their thickness directions) with respect to the ratchet gear 74.

[0072] Further, the cam bracket 80 is configured such that the central portion in the longitudinal direction is rotatably supported, the cam 82 is held at the rear portion which is one end portion side in the longitudinal direction, and the rotor engaging surface 80D at the front portion which is the other end portion side in the longitudinal direction can be pressed by the rotor 78. Here, the rotor engaging surface 80D is an inclined surface that inclines upward in the front direction so as to approach the lower end surface of the rotor 78 as it moves away from the rotation center of the cam bracket 80 in a side view. Therefore, the rotor 78 can efficiently rotate the cam bracket 80 (reduce the rotation range of the cam bracket 80) by its rotation, and as a result, the lock mechanism 70 can be configured compactly.

[0073] Also, when the cam 82 is moved via the cam bracket 80 against the biasing force of the tension coil spring 88 by the rotor 78 so as not to press the cam contact surface 76D of the ball gear 76, the cam bracket 80 moves the ball gear 76 such that the engaging teeth 76B of the ball gear 76 are separated from the engaging teeth 74B of the ratchet gear 74.

[0074] Therefore, when the cam bracket 80 does not move the ball gear 76 so that the engaging tooth 76B separates from the engaging tooth 74B at that time, it is possible to suppress or prevent the occurrence of unlocking failure when unlocking the lock mechanism 70, as compared with a configuration in which, for example, the cam 82 is simply separated from the cam contact surface 76D of the ball gear 76.

[0075] As described above, the vehicle seat 10 according to the present embodiment has been described with reference to the drawings. However, the vehicle seat 10 according to the present embodiment is not limited to the illustrated one, and can be appropriately designed and changed within a range not departing from the gist of the present invention. For example, the shapes of the outer link arm 64 and the inner link arm 66 are not limited to the illustrated shapes. Also, the shapes of the hook 78C and the notch 80F are not limited to the illustrated shapes. For example, the tip of the hook 78C may be formed with a greater plate thickness than other portions so as to be easily engaged with the notch 80F (so as not to be easily disengaged from the notch 80F during locking).

Description of Reference Numerals

[0076] 10 Vehicle seat 14 Seat cushion 60 Link mechanism 64 Outer link arm (first link arm) 66 Inner link arm (second link arm) 70 Lock mechanism 74 Ratchet gear (first gear member) 74B Engaging tooth (first engaging tooth) 76 Ball gear (second gear member) 76B Engaging tooth (second engaging tooth) 76D Cam contact surface (contact surface) 78 Rotor (operating member) 78B Hook (locking portion) 80 Cam bracket (cam holding member) 80D Rotor engaging surface (inclined surface) 80F Notch (locked portion) 82 Cam 88 Tension coil spring (biasing member) 90 Biasing mechanism

Claims

1. It has a first link arm and a second link arm that are rotatably connected at the central portion in the longitudinal direction, and a link mechanism provided on the outer side in the seat width direction on the lower side of the seat of the seat cushion, A locking mechanism that locks the link mechanism by the engagement of a first engaging tooth formed on the end face of a first gear member provided on the first link arm and a second engaging tooth formed on the end face of a second gear member provided on the second link arm, and unlocks the link mechanism by releasing the engagement between the first engaging tooth and the second engaging tooth, A biasing mechanism that biases the second engaging tooth in the meshing direction with respect to the first engaging tooth, and is provided with The biasing mechanism is a cam configured to be able to contact a contact surface that is the end face of the second gear member on the side opposite to the second engaging tooth, a cam holding member that holds the cam and moves the cam in the pressing direction and the pressing release direction with respect to the contact surface, a biasing member that biases the cam holding member so that the cam presses the contact surface, an operating member that moves the cam holding member against the biasing force of the biasing member so that the cam does not press the contact surface, and has The operating member is a vehicle seat having a locking portion that locks to a locked portion formed on the cam holding member only when the cam holding member is biased by the biasing member so that the cam presses the contact surface.

2. The cam holding member is rotatably supported at the central portion in the longitudinal direction, The cam is held on one end side in the longitudinal direction of the cam holding member, and the operating member is configured to be able to press an end face on the other end side in the longitudinal direction of the cam holding member, The end face is an inclined surface that inclines so as to approach the operating member as it moves away from the rotation center of the cam holding member. The vehicle seat according to Claim 1.

3. The vehicle seat according to claim 2, wherein the locked portion is formed on the other end side in the longitudinal direction of the cam holding member.

4. The vehicle seat according to any one of claims 1 to 3, wherein the cam holding member is configured to move the second gear member so that the second engaging teeth are separated from the first engaging teeth when the cam is moved by the actuating member against the biasing force of the biasing member so as not to press the contact surface.

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