JP2000083756A - Headrest - Google Patents

Abstract

PROBLEM TO BE SOLVED: To heighten strength in erecting a headrest pad. SOLUTION: A headrest frame 40 is provided with lock pins 41b, 42b. Support plates 20, 30 are provided with circular-arc first to third guide nodes 22, 23, 32 for permitting rotation of an output shaft 46a of a motor 46 and the lock pins 41b, 42b, and first to third notches 22a, 23a, 32a formed by notching the inside walls of the upper end parts of the holes in the radial direction. Cam parts 45b, 48b are respectively provided on a sector gear 45 fixed to the support plate 20 and the output shaft 46a of the motor 46. The headrest frame 40 is displaced upward through a pinion gear 48 and the sector gear 45 by rotation of the motor 46, so that the output shaft 46a of the motor 46 and the lock pins 41b, 42b are respectively engaged with the first to third notches 22a, 23a, 32a.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a headrest in which a headrest pad is rotatably mounted on a headrest stay fixed to a seat back frame.

[0002]

2. Description of the Related Art Conventionally, in a headrest of this type, a headrest stay fixed to a seatback frame and a headrest fixed to the same stay and opposed to each other as shown in, for example, Japanese Utility Model Laid-Open No. 5-4948. A headrest frame to which a headrest pad is fixed while being rotatably assembled to a pair of support plates, wherein a sector gear is fixed to the support plate, a motor is fixed to the headrest frame, and a sector gear is fixed to an output shaft of the motor. It is well known that a pinion gear meshing with the headrest is fixed, and the headrest pad rotates in the front-rear direction with respect to the headrest stay in response to the rotation of the motor.

[0003]

However, in the above-mentioned conventional headrest, when the headrest pad is in an upright state and the rotation of the motor is stopped, both gears are stopped while the teeth of the sector gear and the pinion gear mesh with each other. As a result, the headrest pad is maintained in an upright state. When a large impact force is applied to the headrest pad while the headrest pad is maintained in an upright state, there is a problem that the teeth of both gears meshing with each other are broken by the same impact force.

[0004]

SUMMARY OF THE INVENTION The present invention has been made to address the above problems, and an object thereof is to maintain sufficient strength with a simple structure when a large impact force is applied when the headrest pad is raised. To provide a headrest.

In order to achieve the above object, a structural feature of the present invention is that a lock pin fixed to a headrest frame is provided, and a lock is provided on a support plate as the headrest pad is turned from a standing state to a falling state. In addition to providing an arc-shaped guide hole allowing rotation of the pin, a notch is formed by radially cutting out the inner wall of the guide hole facing the lock pin when the headrest pad is in the upright state, and the headrest pad is When the headrest pad is in the upright state, a cam portion is provided on at least one of the sector gear and the pinion gear so that the lock pin enters the notch by rotation of the motor corresponding to the direction opposite to the rotation direction from the upright state of the headrest pad to the overturning state. It has been provided.

In the present invention thus constructed, when the headrest pad is in the upright state, that is, when the lock pin is located at a position facing the notch, the motor rotates the pad from the upright state to the overturned state. When rotated in a direction corresponding to the opposite direction, the pinion gear rotates, the headrest frame is displaced via the pinion gear and the motor by the action of the cam portion, and the lock pin provided on the frame enters the notch. As a result, the rotation of the headrest frame with respect to the support plate is prohibited, and the headrest frame (headrest pad) is locked to the support plate while standing up (locked state). Therefore,
Even if a large impact force is applied when the headrest pad is locked, the lock pin maintains the upright state of the headrest pad in cooperation with the notch, so that the teeth of the sector gear and the pinion gear have the same impact force as in the above-described conventional device. Can be prevented from being damaged.

Another structural feature of the present invention is that the output shaft of the motor is passed through the support plate, and the rotation of the output shaft of the motor is accompanied by the rotation of the headrest pad from the standing state to the falling state. When an arcuate guide hole is allowed and the headrest pad is in an upright state When the headrest pad is in an upright state, a notch is formed by radially cutting out the side wall of the guide hole facing the output shaft of the motor. The rotation of the motor corresponding to the direction opposite to the rotation direction from the standing state of the headrest pad to the overturned state,
A cam portion is provided on at least one of the sector gear and the pinion gear so that the output shaft of the motor enters the notch.

According to another feature of the present invention having the above-described structure, when the headrest pad is in an upright state, that is, when the output shaft of the motor is located at a position facing the notch, the motor is turned over from the upright state of the pad. When the pinion gear is rotated in a direction corresponding to the direction opposite to the turning direction to the state, the pinion gear rotates and the output shaft of the motor is displaced via the pinion gear by the action of the cam portion, and the output shaft enters the notch. As a result, the rotation of the motor and the headrest frame with respect to the support plate is prohibited, and the headrest frame (headrest pad) is locked to the support plate while standing (locked state). Therefore, also in this case, even if a large impact force is applied when the headrest pad is locked, the output shaft of the motor cooperates with the notch to maintain the upright state of the headrest pad, so that the teeth of the sector gear and the pinion gear have the same impact. It can be prevented from being damaged by force.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the accompanying drawings. FIGS. 1 and 2 show a locked state of a headrest fixed to a seat back frame according to the embodiment. It is a schematic front view and a schematic side view.

The headrest includes a headrest stay 10 formed of a substantially U-shaped rod-shaped metal material, and a pair of support plates 20 and 30 formed of a substantially semicircular metal plate and fixed to the stay 10. And a headrest frame 40 formed of a metal plate with a substantially U-shaped cross section and rotatably assembled to the plates 20 and 30.

The headrest stay 10 has left and right sides 11 and 12 parallel to each other and an upper side 13 connecting the upper ends thereof, and is supported by a seat back 50. The lower ends of the left and right sides 11, 12 are respectively assembled to a pair of support portions 51a, 51a fixed to the upper side of the seat back frame 51 constituting the seat back 50, and the left and right sides 11, 12 of the stay 10 are connected to the seat back 50. Projecting substantially vertically from the upper end.

A pair of support plates 20 and 30 are fixed to the upper left and right ends of the upper side 13 at the lower part thereof in parallel with the left and right sides 11 and 12 so as to face each other. FIG.
As shown in (1), the left support plate 20 is provided with a through hole 21 in the lower front part thereof, and first and second arcuate guide holes 22 and 23 centered on the hole 21. The widths of the first and second guide holes 22 and 23 are set slightly larger than the outer diameter of the output shaft 46a of the motor 46 and the height of the lock pin 41b in the vertical direction, which will be described later. At the upper ends of the first and second guide holes 22 and 23, there are provided first and second notches 22a and 23a, respectively, in which the side walls of both the guide holes 22 and 23 are cut out in the radial direction. The first and second notches 22a, 23
a of the output shaft 46 of the motor 46 described later.
a is set to be slightly larger than the outer diameter of the lock pin 41b and the width of the lock pin 41b in the front-rear direction, and the height in the vertical direction is set to be substantially equal to the outer diameter of the output shaft 46a of the motor 46.

The right support plate 30 is provided with a through hole 31 at a position in front of and below the through hole 21 of the left support plate 20, and an arc-shaped third guide centered on the hole 31. A hole 32 is provided, and at the upper end of the guide hole 32, a third notch 32 a is formed by radially cutting a side wall of the guide hole 32. The width of the third guide hole 32 is determined by a lock pin 42 described later.
b is set slightly larger than the height in the vertical direction, and the width of the third notch 32a in the front-rear direction is set slightly larger than the width of the lock pin 41b described later in the front-rear direction.
The height in the vertical direction is set substantially equal to the outer diameter of the output shaft 46a of the motor 46.

A headrest frame 40 is rotatably mounted on the pair of support plates 20, 30. The headrest frame 40 includes left and right plates 41 and 42 parallel to each other and an upper plate 43 connecting the upper ends thereof. Under the left and right side plates 41, 42, both left and right side plates 41,
Elliptical through holes 41a and 42a having the same longitudinal direction as the longitudinal direction of 42 are provided respectively. A left side plate 41 is rotatably mounted inside the left support plate 20 by a pin 44 penetrating the through hole 21 and the through hole 41a, and a sector gear 45 having the pin 44 penetrated outside the left side plate 41. Installed. Pin 4
At the outer end of 4, a locking portion on a disk is formed for retaining. The sector gear 45 has a meshing portion 45a formed of teeth provided along substantially one-fourth of the entire circumference and a cam portion 45b adjacent to the portion 45a, and the cam portion 45b is connected to the first notch 22a. And the meshing portion 45a is fixed to the left support plate 20 so as to face the first guide hole 22. The height of the cam portion 45b is set substantially equal to the height of the teeth of the meshing portion 45a. A right side plate 42 is rotatably mounted inside the right support plate 30 by a pin 44 passing through the through hole 31 and the through hole 42a. At the inner end of the pin 44, a locking portion on a disk is formed for retaining.

Left and right side plates 4 of headrest frame 40
The left and right support plates 2 are almost at the center of the outer surfaces of
Rectangular lock pins 41b and 42b penetrating the second and third guide holes 23 and 32 of 0 and 30 are provided, respectively. On the outer surface of the left side plate 41, a motor 46 is attached at an upper portion thereof with a plurality of screws 47 penetrating through a plurality of through holes 41c provided in the same plate 41. The motor 46 has a built-in transmission mechanism. An output shaft 46a of the motor 46 projects horizontally from a lower part of the housing of the motor 46, penetrates through the first guide hole 22 of the left support plate 20 and the through hole 41d of the left side plate 41, and has a left end plate at its tip. 41 rotatably supported. This output shaft 4
6a, a pinion gear 4 outside the left support plate 20 is provided.
8 is fixed, and the gear 48 has a meshing portion 48a composed of teeth provided along substantially 1/4 of the entire circumference and a cam portion 48b adjacent to the same portion 48a. The meshing portion 48a meshes with the meshing portion 45a of the sector gear 45.
The height of the cam portion 48b is set to be greater than the height of the teeth of the meshing portion 48a, and the cam portion 48b cooperates with the cam portion 45b of the pinion gear 45 to move the output shaft 46a and the lock pin 41b of the motor 46 to the first and second positions. Second notch 22a, 23a
To invade.

A headrest pad 60 is fixed to the headrest frame 40. Below the upper plate 43 of the headrest frame 40, both left and right plates 41, 42 are provided.
Is fixed, and the support member 49 has screw holes 49a, 49a. Support material 4
9 has the same frame 40, left and right support plates 20, 3
0, a resin case (not shown) covering the motor 46 and the like
Are assembled by screws screwed into the screw holes 49a, 49a. The headrest pad 60 is formed of an elastic material in a substantially rectangular shape, and is integrally assembled to the case so as to cover the case.

Next, the operation of the headrest configured as described above will be described. As shown in FIG. 4, when the headrest pad 60 is in the upright state, that is, the output shaft 46a of the motor 46 is located at a position facing the first notch 22a, and the two lock pins 41b, 42b
When the motor 46 is at a position facing the second and third notches 23a and 32a, respectively, the motor 46 is turned clockwise in FIG. 4 (a direction corresponding to the direction of rotation of the headrest pad 60 from the standing state to the falling state). When the pinion gear 48 rotates, the pinion gear 48 is displaced downward and backward along the meshing portion 45a of the sector gear 45 while rotating, and the output shaft 46 of the motor 46 is rotated.
a is rotated rearward about the pin 44 along the first guide hole 22, and the output shaft 46a and the motor 46
The headrest frame 40 also pivots rearward about the pin 44 via. At this time, both lock pins 41b,
42b also rotates rearward about the pin 44 along the second and third guide holes 23 and 32. Then, as shown in FIG. 5, the output shaft 46a of the motor 46 and both lock pins 4
1b and 42b are the first, second and third guide holes 2 respectively.
When the headrest frame 40 reaches the position where it comes into contact with the lower end side walls, the rotation of the headrest frame 40 is prohibited, and the frame 40 (headrest pad 60) falls down.

Conversely, when the headrest pad 60 is in the overturned state, that is, when the output shaft 46a of the motor 46 and the lock pins 41b and 42b are at the lower end side walls of the first, second and third guide holes 22, 23 and 32. When the motor 46 is rotated in a counterclockwise direction in FIG. 5 (a direction corresponding to the direction of rotation of the headrest pad 60 from the overturned state to the upright state) when the motor 46 is in contact with the pinion gear 48, the pinion gear 48 rotates. The output shaft 46a of the motor 46 is displaced upward and forward along the meshing portion 45a of the sector gear 45, and
The headrest frame 40 also pivots forward about the pin 44 along the guide hole 22 while pivoting forward around the pin 44 via the output shaft 46 a and the motor 46. At this time, the lock pins 41b and 42b also rotate forward about the pin 44 along the second and third guide holes 23 and 32. Then, the headrest frame 40 (headrest pad 60) returns to the upright state.

Further, when the motor 46 is rotated in a direction corresponding to the direction of rotation of the headrest pad 60 from the overturned state to the upright state, the pinion gear 48 is rotated and the cam portion 4 is rotated.
8b, the output shaft 4 of the motor 46 is displaced upward.
6a is displaced upward and enters the first notch 22a, and the headrest frame 40 is also displaced upward via the output shaft 46a and the motor 46. At this time, both lock pins 41b and 42b are also displaced upward and enter the second and third notches 23a and 32a. The output shaft 46a of the motor 46 and both lock pins 41b and 42b are the first,
When the motor 46 reaches a position where it comes into contact with the upper end side wall of the second and third notches 22a, 23a, 32a, the rotation of the motor 46 is stopped, and the rotation of the output shaft 46a of the motor 46 and the headrest frame 40 are prohibited. 40 (headrest pad 60) stand upright and left support plate 2
Locked at 0, 30 (locked state).

Therefore, according to the headrest constructed as described above, even if a large impact force is applied when the headrest pad 60 is locked, the output shaft 46 of the motor 46 can be used.
a and the lock pins 41b and 42b cooperate with the first, second and third notches 22a, 23a and 32a to maintain the headrest pad 60 in the upright state.
5 and the teeth of the pinion gear 48 can be prevented from being damaged by the same impact force.

In the above embodiment, the motor 4
6 and the first output shaft 46a and the lock pins 41b, 42b.
Although the headrest pad 60 is maintained in the upright state by the engagement with the notches 22a, 23a, and 32a, as shown in FIG. 6, the output shaft 46a of the motor 46 and the first notch 22a are connected to each other. The engagement is stopped and the lock pin 41 is released.
The headrest pad 60 may be maintained in an upright state by the engagement of the second and third notches 23a, 32a with the b, 42b. In this case, the width of the first guide hole 22 provided in the left support plate 20 of the above embodiment is increased to the width including the radial length of the first notch 22a to form the fourth guide hole 25, and the first notch 22 is formed. 22a may be omitted.

Also in this modification, when the headrest pad 60 is in the upright state, the motor 46 is rotated in the counterclockwise direction (a direction corresponding to the direction of rotation of the headrest pad 60 from the overturned state to the upright state). Then, since the output shaft 46a of the motor 46 can be displaced upward,
The headrest frame 40 is displaced upward, and both lock pins 41b, 42b are in the second and third notches 23a, 32a.
Invade. Other operations are the same as in the above embodiment. As a result, the two lock pins 41b and 42b cooperate with the second and third notches 23a and 32a to form the headrest pad 60.
, The teeth of the sector gear 45 and the pinion gear 48 can be prevented from being damaged by the same impact force.

The headrest pad 60 is driven only by the engagement between the output shaft 46a of the motor 46 and the first notch 22a.
May be maintained in an upright state. In this case, as shown in FIG. 7, the lock pins 41b and 4
2b and the second and third notches 23a and 32a may be omitted.

Also in this modification, when the headrest pad 60 is in the upright state, the motor 46 is rotated in the counterclockwise direction (the direction corresponding to the direction of rotation of the headrest pad 60 from the overturned state to the upright state). Then, the output shaft 46a of the motor 46 is displaced upward, and
a enters the first notch 22a. Other operations are the same as in the above embodiment. As a result, the output shaft 46 of the motor 46
a cooperates with the first notch 22a to form the headrest pad 6
Since the upright state of 0 is maintained, it is possible to prevent the teeth of the sector gear 45 and the pinion gear 48 from being damaged by the same impact force.

In the above-described embodiment and the modified example, the cam portion 45 is provided on the sector gear 45 and the pinion gear 48.
Although the b and 48b are provided respectively, the cam portion 45b may not be provided on the sector gear 45, and the cam portion 48b may be provided only on the pinion gear 48. This also allows the output shaft 46 of the motor 46 to be driven by the action of the cam portion 48b.
a and both lock pins 41b and 42b enter the first to third notches 22a, 23a and 32a, so that the same operation and effect as those of the above-described embodiment and modification can be obtained.

In the above embodiment and the modified example, the motor 46 is connected to the left side plate 4 of the headrest frame 40.
1, but may be attached to the inner surface of the side plate 41. In this case, the output shaft 46a of the motor 46 projects from the inside of the left side plate 41 to the outside of the left support plate 20 via the through-hole 41d of the left side plate 41 and the first guide hole 22 of the left support plate 20. The pinion gear 48 is fixed. Thus, when the headrest pad 60 is in the upright state, the motor 46
Is rotated in the counterclockwise direction (a direction corresponding to the direction of rotation of the headrest pad 60 from the falling state to the standing state), the output shaft 46a of the motor 46 is displaced upward,
Since the output shaft 46a enters the first notch 22a, the same operation and effect as those of the above-described embodiment and the modified example can be obtained.

[Brief description of the drawings]

FIG. 1 is a schematic front view showing a locked state of a headrest fixed to a seat back frame according to an embodiment of the present invention.

FIG. 2 is a schematic side view showing a locked state of a headrest shown in FIG. 1;

FIG. 3 is an exploded perspective view of the headrest shown in FIG.

FIG. 4 is a schematic side view showing an upright state of the headrest shown in FIG. 1;

FIG. 5 is a schematic side view showing the headrest shown in FIG. 1 in a falling state.

FIG. 6 is an exploded perspective view of a headrest according to a first modification of the present invention.

FIG. 7 is an exploded perspective view of a headrest according to a second modification of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... Headrest stay, 20, 30 ... Support plate, 21, 31, 41a, 41c, 41d, 42a ... Through-hole, 22 ... 1st guide hole, 22a ... 1st notch, 23
... second guide hole, 23a ... second notch, 32 ... third guide hole, 32a ... third notch, 40 ... headrest frame, 41 ... left side plate, 41b ... lock pin, 42 ... right side plate, 42b ... lock Pin, 43: Upper plate, 44: Pin, 4
5: sector gear, 45a, 48a: meshing portion, 46: motor, 46a: output shaft, 47: screw, 48: sector gear,
48b cam part, 49 support member, 50 seat back,
51 ... seat back frame, 51a ... support part, 60 ...
Headrest pad.

Claims (2)

[Claims] 1. A headrest stay fixed to a seatback frame at a lower portion, a pair of support plates fixed to the headrest stay and opposed to each other, and rotatable about a first rotation axis by the pair of support plates. A headrest frame fixed to the headrest pad and fixed thereto, a sector gear fixed to the support plate around the first rotation axis, a motor fixed to the headrest frame to rotate an output shaft, A pinion gear fixed to an output shaft of a motor and meshing with the sector gear, wherein the headrest pad is rotatably mounted to the headrest stay in accordance with rotation of the motor, and is fixed to the headrest frame. With lock pin The support plate is provided with an arc-shaped guide hole that allows the lock pin to rotate with the rotation of the headrest pad from the upright state to the overturned state, and the lock pin is turned on when the headrest pad is in the upright state. A notch formed by radially notching the side wall of the opposed guide hole is provided, and when the headrest pad is in the upright state, the headrest pad corresponds to the direction opposite to the rotation direction from the upright state to the overturned state. A headrest provided with a cam portion on at least one of the sector gear and the pinion gear so that the lock pin enters the notch by rotation of the motor. 2. A headrest stay fixed at a lower portion to the seat back frame, a pair of support plates fixed to the headrest stay and facing each other, and rotatable about the first rotation axis by the pair of support plates. A headrest frame fixed to the headrest pad and fixed thereto, a sector gear fixed to the support plate around the first rotation axis, a motor fixed to the headrest frame to rotate an output shaft, A pinion gear fixed to an output shaft of a motor and meshing with the sector gear, wherein the headrest pad is rotatably assembled with respect to the headrest stay in accordance with rotation of the motor. When the output shaft of the motor is penetrated The headrest pad is provided with an arc-shaped guide hole for allowing rotation of the output shaft as the headrest pad is turned from the upright state to the overturned state, and the output shafts of the motor are opposed to each other when the headrest pad is in the upright state. A notch in which a side wall of the guide hole is cut out in a radial direction, the motor corresponding to a direction opposite to a rotating direction of the headrest pad from a standing state to a falling state when the headrest pad is in a standing state. A headrest provided on at least one of the sector gear and the pinion gear so that the output shaft of the motor enters the notch by the rotation of the motor.