JP2006219076A - Vehicle seat - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vehicle seat capable of supporting certainly the head of an occupant with a headrest despite its constitution such that the headrest is moved forward upon sensing a backward movement of the occupant. <P>SOLUTION: A headrest mounting rod 10 having once moved upward is willing to return to the original position upon receiving the load of the backward movement due to the inertia of the occupant's head, while an engaging piece 51 retreated from the moving locus K turns backward due to the inertia acting on the mass of the engaging piece itself quicker than the headrest mounting rod descending to return to the original position and is engaged with the undersurface of the headrest mounting rod, and the head supporting condition of the headrest 6 is held as it is. An engaging bend 53 is formed inclining ahead down while an abutting surface 55 is formed inclining with tail down, and when the engaging piece 51 turns from the position where a spring 61 for retreating abuts to a turn stopper 62, the undersurface of the headrest mounting rod gets over the abutting surface 55 to be engaged with the engaging bend 53 to generate going beyond the dead point M (boundary between the bend 53 and the abutting surface 55), which causes the two members to lock each other. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a vehicle seat provided with a headrest that moves forward to support a head during a so-called “rear impact” in which a seated person moves backward due to inertia in response to a collision from the rear.

Conventionally, a configuration in which a headrest provided on an upper portion of a backrest seat rotates forward by a movable frame in a backrest seat located behind the back of the seated person to support the head of the seated person is known. There is (for example, Patent Document 1).
JP-A-10-119619

In the known example, the back of the seated person moves to the rear side due to the inertia at the time of the rear collision, so that the movable frame is moved backward. Supporting the department.
At this time, the inertia of the rear impact also acts on the head, and the head is heavy, so if the head moves backward, the chest will come to the front and move when the headrest supports the head There is a problem in that the load applied to the frame is reduced, the headrest once moved forward returns to the rear side, and sufficient head support force cannot be obtained.
In the present application, the headrest is supported by the headrest while the headrest is moved forward by detecting the backward movement of the seated person.

In the present invention, a headrest 6 formed by providing a pillar 8 on a head support portion 7 that supports at least a head of a seated person is attached to a backrest frame 3 via a link mechanism L so as to be movable forward. The dorsal frame 3 located behind the waist is provided with a rear impact detector 25 for detecting the backward movement of the seated person due to inertia, and the rear impact detector 25 and the link mechanism L of the headrest 6 detect the rear impact. The headrest 6 is moved forward by the movement of the body 25 so as to support the head of the seated person, and the headrest 6 and the dorsal frame 3 are positioned so as to support the head at the time of a rear collision. A holding mechanism 50 having an engagement piece 51 for holding the headrest 6 moved forward at that position is provided, and the engagement piece 51 has an inertia enough to move the headrest 6 forward by the rearward movement of the rear collision detector 25. Arise In some cases, the inertial force acts on the mass of the engagement piece 51 itself to engage with a part of the link mechanism L or the headrest 6 and keep the headrest 6 moved forward as it is, and for retraction. A spring 61 is always urged so as not to engage with a part of the link mechanism L or the headrest 6, and in the vicinity of the engagement piece 51, a revolving rotation of the engagement piece 51 is stopped at a predetermined position. The vehicle seat is provided with a moving stopper 62.
In the present invention, a part of the link of the headrest 6 is a headrest mounting rod 10 fixed to an upper link rod 15 provided on the back frame 3, and the headrest mounting rod 10 is returned to the engagement piece 51. An abutting contact surface 55 and an engagement bending portion 53 for holding the moving state of the headrest mounting rod 10 are provided, and the engagement bending 51 is based on the rotation direction toward the headrest mounting rod 10. The part 53 is a vehicular seat formed in a front downward inclination, and the contact surface 55 is formed in a rear downward inclination.
In the present invention, the engaging piece 51 is rotatably attached to a bracket 60 provided on the upper frame 57 of the dorsal frame 3 by a mounting shaft 58, and the contact surface 55 of the engaging piece 51 is attached to the mounting shaft 58. Is provided with the retracting spring 61 for urging the headrest mounting rod 10 so as to retract, and the bracket 60 is provided with the rotation stopper 62.
In the present invention, a plate body 31 formed in a substantially rectangular single plate shape is attached to the front side of the rear collision detection body 25 so as to be movable back and forth with respect to the back frame 3 of the back sheet 2. A plate-like support member 30 is provided, and the upper portion of the plate body 31 is a vehicle seat that is as close as possible to the upper frame 57 of the dorsal frame 3.

In the first aspect of the invention, not only can the head support state of the headrest 6 be held by the holding mechanism 50 to improve the certainty of prevention of whiplash, but also the retracting spring 61 and the rotation stopper 62 are provided. Thus, even if the headrest 6 moves other than the impact of the collision, it can be configured to be able to return to the original position, and the headrest 6 can be prevented from becoming unusable.
According to the second aspect of the present invention, the contact surface 55 is normally retracted from the headrest mounting rod 10 to allow the headrest 6 to return to its original position even if the headrest 6 moves other than the impact of the collision. The engagement bent portion 53 engages with the headrest mounting rod 10 beyond the contact surface 55 of the combined piece 51 to reliably prevent the headrest mounting rod 10 from returning.
In the invention of claim 3, since the retracting spring 61 is provided on the mounting shaft 58 and the rotation stopper 62 is provided on the bracket 60, respectively, a rational configuration that is compact and easy to mount can be achieved.
In the invention of claim 4, the headrest 6 is prevented from returning and the head support state is improved, the upper body of the seated person is supported by the plate body 31, and the seated person is supported in an extremely stable posture. The effect of preventing whiplash can be improved.

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to the drawings. Reference numeral 1 denotes a vehicle seat, 2 denotes a back seat of the vehicle seat 1, and the back seat 2 attaches a cushion material 4 to a back frame 3, and the cushion material The outer periphery of 4 is surrounded by the skin member 5.
A headrest 6 is provided on the upper portion of the dorsal seat 2. The configuration of the headrest 6 is arbitrary, and includes at least a head support portion 7 that supports the head of the seated person and a pillar 8 that is attached to the dorsal seat 2.
The pillar 8 of the headrest 6 is attached to a pillar support member 11 provided on the headrest attachment rod 10 in the left-right direction so that the height can be adjusted. Although the structure of the pillar 8 and the pillar support member 11 is well-known and illustration is abbreviate | omitted, it selectively selects to the engagement recessed part formed in the pillar 8 which located the engagement member provided in the pillar support member 11 in desired height. What is necessary is just to engage and hold | maintain.
The left and right sides of the headrest mounting rod 10 are fixed to the upper portion of the upper link rod 15 that moves the headrest 6 back and forth. An upper and lower intermediate portion of the upper link rod 15 is rotatably attached to a side frame 17 of the back frame 3 by a rotation shaft 16. The upper part of the transmission member (rod) 20 is attached to the lower part of the upper link rod 15 by the shaft 21.

In this case, the upper link rod 15 is formed on the upper link arm portion 22 on the upper side of the rotation shaft 16, and is formed on the lower link arm portion 23 on the lower side of the rotation shaft 16. The arm portion 23 is formed in an inverted “<” shape, and the upper link arm portion 22 is formed longer than the lower link arm portion 23. Further, the upper link rod 15 is attached so as to be inclined so that the lower link arm portion 23 is positioned on the front side as it goes downward with respect to the rotation shaft 16.
Therefore, the backrest frame 3 is provided with a rear collision detector 25 that moves backward when a seated person who has collided from behind moves backward due to inertia. The rear impact detection body 25 is attached to the lower part of a pair of lower links 26 provided on the dorsal frame 3 by attachment shafts 27 on both sides thereof. The upper part of the lower link 26 is pivotally attached to the side frame 17 of the dorsal frame 3 by a pivot shaft 28. The lower part of the transmission member 20 is attached to the upper and lower intermediate parts of the lower link 26 by a shaft 29, and when the rear collision detector 25 moves rearward due to the backward movement of the seated person, this energy causes the lower link 26 and the transmission member 20 to move. The upper link rod 15 moves the headrest 6 forward to support the seated person's head.

In this case, when the rear collision detector 25 moves backward, the lower link 26 pulls the transmission member 20 downward, the transmission member 20 rotates the lower portion of the upper link rod 15 downward, and the upper portion of the upper link rod 15 The headrest 6 is moved forward by rotating forward.
Therefore, the upper link rod 15 amplifies the amount of movement of the rear collision detector 25 to move the headrest 6 forward, so that the amount of movement of the headrest 6 can be sufficiently secured and the head of the seated person is reliably supported. .
Thus, the members of the lower link 26 and the upper link rod 15 are formed in a plate shape, and are attached to the left and right side frames 17 of the dorsal frame 3, respectively. The rear collision detector 25 is only located between the two, and does not give the seated person an uncomfortable or uncomfortable feeling when sitting.
Therefore, a plate-like support member 30 is provided on the dorsal frame 3 of the dorsal seat 2. The plate-like support member 30 supports the upper body of the seated person (upper body including the waist). The plate-like support member 30 supports the upper body of the seated person with a “surface”, stabilizes the sitting posture, and makes the headrest 6 support well.

In other words, in the conventional zigzag spring configuration arranged vertically, the upper body of the seated person is supported by “line” by each zigzag spring that moves backward due to the load, so the seating posture is not stable and moves forward in the case of a rear collision. Even if the headrest 6 supports the head, the upper body of the seated person moves backward, and the positional relationship between the head and the upper body becomes unstable. Since the entire upper body of the seated person can be supported by the “surface” and the headrest 6 moving forward supports the head, the plate-like support member 30 supports the upper body of the seated person by the “surface”. The seating posture of the seated person including the head is extremely stabilized.
The plate-like support member 30 is formed by a substantially rectangular single plate-like plate body 31, and the plate body 31 is seated while having a predetermined strength capable of supporting a seated person by a synthetic resin such as polypropylene. If the load is supported while being elastically deformed to some extent when it receives a rear load (including the case of weight) from a person, it is preferable because the feeling at the time of back contact called “contact” can be made flexible.

The plate-like support member 30 is configured by attaching the plate body 31 to the dorsal frame 3 through a wire spring 32 such as a zigzag spring or a formed wire spring so as to be movable back and forth. Support the seated person back and forth while holding.
In this case, the wire spring 32 has a predetermined elasticity, and is configured such that when a load is applied to the plate body 31, the entire plate body 31 can move rearward while maintaining the surface shape.
Thus, the upper edge of the plate body 31 is formed in an upper arc portion 33 having a low arc shape at the center, and the upper arc portion 33 is positioned above the vicinity C of the ninth seat of the average seated person.

The vicinity of the ninth thoracic vertebra is the position of the center of gravity of the upper body and is a portion that does not change in the spinal column in the sitting posture (the amount of movement is small), and the upper edge of the plate body 31 is positioned above the vicinity of the ninth thoracic vertebra. Thus, the plate-like support member 30 supports the position of the center of gravity of the upper body of the seated person.
In this case, the upper wire spring 32A of the wire springs 32 is located slightly below the ninth thoracic vertebra vicinity C and supports the load applied obliquely rearward and downward from the ninth thoracic vertebra vicinity C. It is suitable because it can effectively support the upper body.
Accordingly, the upper side edge 35 of the upper portion 34 of the plate body 31 having the upper arc portion 33 is formed in a substantially linear shape so that the upper portion 34 has substantially the same left-right width. Thereby, the upper part 34 can support a seated person's upper body in a surface state.

The plate middle portion 36 of the plate body 31 below the upper portion 34 has left and right side edges formed in an arc-shaped middle arc portion 37 so that the upper and lower middle portions are narrowest. The vicinity of the waist of the seated person does not require much support in the seating posture, but rather causes seating fatigue and low back pain due to compression. Therefore, the left and right side edges of the plate middle portion 36 are formed in the middle arc portion 37, so The person. In addition, the size in the vicinity of the seated person's waist varies greatly among individuals. In this respect as well, it is preferable to form the plate intermediate portion 36 of the plate body 31 in the intermediate arc portion 37.
In this case, the rear collision detector 25 is positioned behind the plate middle portion 36 of the plate body 31.
That is, by providing the plate-like support member 30 on the dorsal frame 3, it is possible to detect a rear-end collision if the rear-end collision detector 25 is provided behind any portion from the upper end to the lower end of the plate-like support member 30. The plate intermediate portion 36 of the plate-like support member 30 has a large rearward movement amount, and when the rear impact occurs, the rear impact detector 25 can be moved greatly to reliably detect the rear impact, and the rear impact detector 25. The upper part of the plate-shaped support member 30 is moved backward by a predetermined amount, and the support of the upper body of the seated person is insufficient. The rear collision detector 25 is positioned.
Therefore, both the support of the seated person by the plate-like support member 30 and the certainty of the detection of the rear collision by the rear collision detector 25 can be achieved.

Thus, the lower portion 40 of the plate body 31 below the plate intermediate portion 36 forms iliac support portions 41 protruding laterally on the left and right sides, respectively, and the lower side from the iliac support portion 41 goes downward. A sacrum support portion 43 is formed on the lower arc portion 42 of a narrow arc shape and protrudes downward at the junction of the left and right lower arc portions 42.
That is, by supporting the vicinity of the iliac R portion forming the upper part of the pelvis by the iliac support portion 41, the waist of the seated person is surely held.
Similarly, by supporting the vicinity of the sacrum S portion of the seated person by the sacrum support part 43, the seated person's waist is securely held.
Thus, when the lower wire spring 32B of the wire spring 32 is positioned above the iliac support portion 41 and below the narrowest width portion of the intermediate arc portion 37, the waist of the seated person is effectively used. It can be supported and is suitable.
That is, the upper wire spring 32A and the lower wire spring 32B support the vicinity of the seated person's ninth thoracic vertebra and the vicinity of the pelvis / sacrum, so that the seated person's back (waist) is supported at two upper and lower points. By suppressing the pressure applied to the spine between the lower wire spring 32 </ b> B and the lower wire spring 32 </ b> B, an effect of reducing fatigue during sitting can be expected, which is preferable.

In addition, since the lower wire spring 32B is provided in the vicinity of the pelvis and sacrum, the lower portion of the plate-like support member 30 becomes a “plane” in the case of a rear collision and moves backward integrally, thereby detecting the rear collision. It is also expected that the body 25 is reliably moved backward to ensure the detection of a rear collision.
Thus, the upper and lower wire springs 32A and 32B are arranged in parallel at the upper and lower wire springs 32A, and the single plate-like plate body 31 is supported at four upper and lower and left and right positions, and is seated on the planar body. Support the person. The upper wire spring 32A and the lower wire spring 32B of the wire spring 32 are both attached to the dorsal frame 3 in a fixed state at both left and right ends, and an intermediate portion thereof is formed in a bent portion 44 that is appropriately bent in the vertical direction. The bent body 44 is configured to support the plate body 31 in a surface state.
Further, the left and right intermediate portions of the wire spring 32 fix a predetermined portion of the bent portion 44 to the plate-like support member 30 with an arbitrary configuration such as a locking tool 45.

Thus, one end of the spring 18 is locked to the upper link arm portion 22 of the upper link rod 15, and the other end of the spring 18 is locked to the side frame 17. Further, one end of the spring 19 is locked to the lower link 26, and the other end of the spring 19 is locked to the side frame 17. The spring 18 and the spring 19 urge the upper link bar 15 and the lower link 26 so that the headrest 6 is held at a predetermined position on the rear side.
That is, the spring 18 biases the upper link arm portion 22 to rotate downward, and the spring 19 biases the lower link 26 to rotate downward.
A holding mechanism 50 is provided between the headrest 6 and the dorsal fin frame 3 to hold the headrest 6 moved forward to support the head at the time of a rear collision in that position.

The holding mechanism 50 is provided so that the engagement piece 51 rotates toward the movement locus K (FIG. 7) from the normal position of the headrest mounting rod 10 of the headrest 6 to the forward movement position at the time of rear collision, It is configured so that it is retracted from the movement locus K in the normal state and is rotated toward the movement locus K in the rear collision to engage with the lower surface of the headrest attachment rod 10 so that the headrest attachment rod 10 (headrest 6) does not return ( FIG. 10).
The engagement piece 51 is formed at the engagement bent portion 53 by bending the upper portion of the front plate 52 to the rear side, and side plates 54 are integrally provided on the left and right side edges of the front plate 52, and the upper portion of the side plate 54 is The headrest mounting rod 10 is formed on the contact surface 55 with which the front surface contacts.
The lower part of the side plate 54 is formed in the attachment part 56, and the attachment part 56 is attached to the upper frame 57 of the dorsal frame 3 by the attachment shaft 58 so as to rotate from the retracted position to the engaged position with respect to the movement locus K.

The axis of the mounting shaft 58 is provided on the upper frame 57 so as to cross the movement locus K. The mounting shaft 58 is mounted on the bracket 60, and the bracket 60 is fixed to the upper frame 57. The attachment shaft 58 is provided with a retracting spring 61 that urges the engagement piece 51 so as to be always away from the headrest attachment rod 10.
One end of the retracting spring 61 may be in contact with the back surface of the front plate 52 of the engagement piece 51, and the other end of the retracting spring 61 may be in contact with an arbitrary fixing portion such as the bracket 60 or the upper frame 57.
Therefore, the bracket 60 is provided with a rotation stopper 62 that stops the rotation of the engagement piece 51 at a position where the contact surface 55 of the engagement piece 51 does not affect the lowering of the headrest mounting rod 10.
The engagement piece 51 is normally positioned in front of the front surface of the headrest mounting rod 10 before the movement of the upper contact surface 55 of the engagement piece 51 or is brought into contact with the front surface of the headrest mounting rod 10.

When the headrest mounting rod 10 is moved up statically regardless of acceleration, the headrest mounting rod 10 is allowed to descend (return to the original position) (return to FIG. 9 to FIG. 7), and the rear impact When the headrest mounting rod 10 moves upward (forward), the engagement bent portion 53 of the engagement piece 51 moves backward due to the inertia acting on the mass of the engagement piece 51 itself at this time, and as a result, the movement locus The headrest mounting rod 10 is configured to rotate toward K and engage with the lower surface of the headrest mounting rod 10 so that the headrest mounting rod 10 does not return downward.
That is, when the engagement bent portion 53 of the engagement piece 51 is engaged with the lower surface of the headrest mounting rod 10, this state is maintained, but when the headrest mounting rod 10 is moved upward by a load not accompanied by acceleration, Even when the engagement bent portion 53 of the engagement piece 51 rotates against the retraction spring 61, the retraction is performed so that the headrest 6 that has moved forward can be restored (returning to FIGS. 9 to 7). The engagement bending portion 53 is configured not to be engaged with the lower surface of the headrest mounting rod 10 by the spring 61 and the rotation stopper 62.

That is, the engagement piece 51 is retracted from the headrest mounting rod 10 when acceleration is not accompanied (FIG. 8), and the contact surface 55 is engaged when the headrest mounting rod 10 is lowered. The combined piece 51 is returned to the original initial position (returned from FIG. 8 to FIG. 7). In the case of a rear collision, the engagement piece 51 is moved toward the movement locus K by the inertia of the mass of the engagement piece 51, regardless of the spring elasticity. The combined piece 51 is rotated so that the engaging bent portion 53 of the engaging piece 51 is engaged with the lower surface of the headrest mounting rod 10 (FIG. 10).
Accordingly, the engagement bent portion 53 is formed in a forward downward inclination and the contact surface 55 is formed in a rear downward inclination, and the boundary between the engagement bent portion 53 and the contact surface 55 is defined as a dead point M (FIG. 9). Matching the point M position with the lower surface height of the headrest mounting rod 10 that will move upward in the rear impact (FIG. 9), the position will overcome the dead point M position, and the engagement bent portion 53 will move to the headrest mounting rod 10 When contacting the lower surface (FIG. 9), the so-called dead point is exceeded, and the engagement piece 51 and the headrest mounting rod 10 are locked to each other.

In this case, if the headrest attachment rod 10 is formed in a round cross section and the contact surface 55 of the engagement piece 51 is formed in a slope shape, the contact area between the headrest attachment rod 10 and the engagement piece 51 is reduced, and the headrest attachment rod 10 is formed. 10 movement and rotation of the engagement piece 51 are ensured, which is preferable.
Thus, the bracket 60 or the upper frame 57 is provided with a stopper 63 that stops the engaging piece 51 rotated by inertia due to the mass at the time of rear collision at a position where the engaging piece 51 is engaged with the lower surface of the headrest mounting rod 10.
Therefore, the engagement bent portion 53 of the engagement piece 51 is reliably engaged with the lower surface of the headrest mounting rod 10.

(Operation of Example)
A plate-like support member 30 is provided on the dorsal frame 3 of the dorsal seat 2, and the plate-like support member 30 is attached to the dorsal frame 3 via a wire spring 32 and a plate body 31 formed in a substantially rectangular single plate shape. Since the plate-like support member 30 is configured to be freely movable back and forth, the plate-like support member 30 moves back and forth while being held to support the seated person.
In addition, since the plate body 31 of the plate-like support member 30 is formed in a substantially rectangular single plate shape, the load applied only to a predetermined portion of the plate body 31 can be increased or decreased by moving the entire plate body 31 backward. Distribute the load to the left and right to support it securely.
That is, for example, if the upper and lower plate bodies 31 are divided and formed, when a load is applied to a portion between the upper and lower plate bodies 31, the upper and lower plate bodies 31 may rotate and cannot reliably support the load. However, in the present application, since the plate-like support member 30 is formed by the substantially rectangular single plate-like plate body 31, the load applied to the middle of the upper and lower sides is reliably received and supported by the entire plate-like support member 30.

Thus, the headrest mounting rod 10 is attached to the dorsal frame 3 via the upper link rod 15, and the pillar support member 11 that supports the pillar 8 of the headrest 6 is fixed to the headrest mounting rod 10. When the seat occupant moves rearward due to inertia from the impact, the plate body 31 moves rearward, the plate body 31 moves the rear collision detector 25 backward, and the lower link 26 is moved by the rear movement of the rear collision detector 25. Rotates to pull the transmission member 20 downward, the transmission member 20 rotates the upper link rod 15 downward about the rotation shaft 16, and the upper portion of the upper link rod 15 rotates forward about the rotation shaft 16. As a result, the headrest 6 moves forward about the axis 21.
Accordingly, the headrest 6 is rotated forward by the upper link rod 15 to support the head, and has an effect of preventing whiplash.

In this case, the rear collision detector 25 is provided on the rear side of the plate body 31 at a predetermined interval assuming the forward / backward movement amount (particularly the backward movement amount) of the plate body 31. The plate body 31 moves back and forth with respect to the dorsal frame 3 to support the cushion material 4 and to improve the cushioning property. Moreover, since the movement direction of the plate body 31 and the rear collision detector 25 is the same, the plate body 31 that is pushed by the seated person due to the inertia caused by the rear collision reliably moves the rear collision detector 25 backward. , Sensing inertia due to impact.
Therefore, both the support of the seated person by the plate-like support member 30 and the certainty of the detection of the rear collision by the rear collision detector 25 can be made compatible, and a rational configuration is obtained.

Further, since it is not necessary to provide the rear impact sensor 25 on the upper rear side of the plate body 31 of the plate-like support member 30, the plate-like support member 30 can reliably support the upper body of the seated person at the time of the rear impact. .
Thus, the upper link rod 15 and the lower link 26 are biased by the spring 18 and the spring 19 so that the headrest 6 always moves backward.
Therefore, the headrest 6 moves forward when inertia due to an impact stronger (larger) than the elasticity of the springs 18 and 19 occurs. At the same time, the headrest 6 moves forward due to the inertial force acting on the head of the seated person. Will act to return to its original position.
In the present application, a holding mechanism 50 is provided between the headrest 6 and the dorsal fin frame 3 to hold the headrest 6 moved forward in order to support the head at the time of the rear collision. The headrest 6 that has moved forward is held as it is by the holding mechanism 50 and reliably supports the head.
Therefore, the effect of preventing whiplash is more reliably exhibited.

In this case, even if the head is supported by the headrest 6 that moves forward during a rear-end collision, the support of the upper body of the seated person may become unstable, and the positional relationship between the head and the upper body may be deteriorated. However, in the present application, since the entire upper body of the seated person is supported by the “plane” by the plate-shaped support member 30, the head and the upper body of the seated person can be favorably supported in combination with the headrest 6 that moves forward, Furthermore, since the support of the head is held by the holding mechanism 50, the seating posture of the seated person is further stabilized.
Thus, the holding mechanism 50 includes an engagement piece 51 and a retraction spring 61 for retracting the engagement piece 51 from the headrest attachment rod 10. The engagement piece 51 attaches the headrest 6 to the back frame 3. Since the headrest mounting rod 10 is provided so as to go in and out of the movement locus movement locus K from the normal position to the forward movement position at the time of the rear collision, the contact of the engagement piece 51 is normally as shown in FIG. The surface 55 is in contact with the headrest mounting rod 10 and is retracted from the movement locus K.

When the headrest mounting rod 10 moves along the movement track K at the time of a rear collision, the engagement piece 51 retracted from the movement track K moves to the original headrest mounting rod due to inertia acting on the mass of the engagement piece 51 itself. It rotates toward the movement locus K at the position 10 and engages with the lower surface of the headrest mounting rod 10, and the headrest supporting state of the seated person of the headrest 6 is maintained as it is (FIG. 10).
That is, the engaging piece 51 of the holding mechanism 50 is attached to the upper frame 57 of the back frame 3 so that the lower part is rotated by the attachment shaft 58 toward the movement locus K. The engagement piece 51 is retracted from the movement locus K, and is rotated toward the movement locus K and engages with the headrest mounting rod 10 at the time of rear collision.

Therefore, the engagement piece 51 can be configured to be engaged with the moved headrest mounting rod 10 simply by providing the engagement piece 51 so as to be rotatable by the attachment shaft 58, and the holding mechanism 50 can be simply configured. .
Thus, the engagement piece 51 before the rear impact is retracted in front of the headrest mounting rod 10, and when the rear impact sensor 25 is moved backward by applying a static load (non-accelerated force), the link The mechanism L (the upper link rod 15, the transmission member 20, and the lower link 26) may transmit the movement allowance to move the headrest mounting rod 10 upward (FIG. 8). Is engaged with the lower surface of the headrest mounting rod 10, the headrest mounting rod 10 cannot be returned to its original position, and the headrest 6 cannot be used.

In the present application, a rotation stopper 62 is provided in the moving path of the engagement piece 51 to be retracted from the headrest mounting rod 10, and the engagement piece 51 is urged by the retraction spring 61 so that it always contacts the rotation stopper 62. Therefore, even if the headrest mounting rod 10 is moved upward due to a static load, the engagement piece 51 does not rotate from the original position as shown in FIG. 8, and the original position of the headrest mounting rod 10 is restored. Allow.
Therefore, when the rear collision detector 25 moves backward due to a static load (non-accelerated force), the engagement piece 51 can be returned to the initial state, and the headrest 6 can be returned to its original position. The 6 unusable state is avoided.
In this case, if the headrest mounting rod 10 is formed in a round cross section, the contact area between the headrest mounting rod 10 and the contact surface 55 of the engagement piece 51 is reduced, and the movement of the headrest mounting rod 10 and the rotation of the engagement piece 51 are reduced. It is preferable to ensure movement.

Although the explanation is partially overlapped, the headrest mounting rod 10 that has once moved up receives the load of backward movement due to the inertia of the head and tries to return to the original position. The engaging piece 51 is faster than the headrest mounting rod 10 that descends to return to the original position, and rotates backward due to the inertia acting on the mass of the engaging piece 51 itself to engage the lower surface of the headrest mounting rod 10, As it is, the head support state of the seated person of the headrest 6 is maintained (FIG. 10).
At this time, since the lower surface of the headrest mounting rod 10 passes over the contact surface 55 of the engagement piece 51 and comes into contact with the engagement bent portion 53 (FIG. 10), the rotation of the engagement piece 51 to the original position is Stops due to the presence of the headrest mounting rod 10.

Accordingly, the headrest mounting rod 10 and the engaging piece 51 are held in contact with each other and are held in this locked state.
That is, the engagement bent portion 53 is formed to have a front downward inclination, the contact surface 55 is formed to have a rear downward inclination, and the engagement piece 51 rotates from a position where the retracting spring 61 contacts the rotation stopper 62. At this time, the lower surface of the headrest mounting rod 10 gets over the contact surface 55 and engages with the engagement bent portion 53, exceeds the so-called dead point M (the boundary between the engagement bend portion 53 and the contact surface 55), and locks to each other. .
Even if the engagement bent portion 53 of the engagement piece 51 is engaged with the lower surface of the headrest mounting rod 10 and the holding mechanism 50 is locked, the headrest 6 is moved forward by manual operation, and the headrest mounting rod When 10 is lifted above the engagement bent portion 53 of the engagement piece 51, the engagement bending portion 53 of the engagement piece 51 is positioned at the returnable position below the headrest mounting rod 10 by the elasticity of the retracting spring 61 ( 8), when the headrest 6 is returned in this state, the headrest mounting rod 10 descends and contacts the contact surface 55 of the engaging piece 51 to retract the engaging piece 51, and the headrest mounting rod 10 and the engaging piece Each 51 returns to its original position (FIG. 7).

The perspective view of a dorsal fin seat and a headrest. FIG. FIG. The perspective view of a dorsal seat frame (a plate-like support material is omitted). The perspective view of a dorsal fin seat frame. Schematic of the sitting state. The vertical side view of a holding mechanism part. The vertical side view of the holding mechanism before a rear collision. The vertical side view of the holding | maintenance state of a holding | maintenance mechanism. FIG. 6 is a longitudinal side view of the locked state with the holding mechanism engaged.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Vehicle seat, 2 ... Backrest seat, 3 ... Backrest frame, 4 ... Cushion material, 5 ... Skin member, 6 ... Headrest, 8 ... Pillar, 10 ... Headrest mounting collar, 11 ... Pillar support member, 15 ... Upper link rod, 16 ... Rotating shaft, 17 ... Side frame, 20 ... Transmission member, 21 ... Shaft, 22 ... Upper link arm, 23 ... Lower link arm, 25 ... Rear collision detector, 26 ... Lower Side link, 27 ... Mounting shaft, 28 ... Rotating shaft, 29 ... Shaft, 30 ... Plate support, 31 ... Plate body, 32 ... Wire spring, 33 ... Upper arc portion, 34 ... Upper portion, 35 ... Upper side Edge, 36 ... Plate middle part, 37 ... Middle arc part, 40 ... Lower part, 41 ... Iliac support part, 42 ... Lower arc part, 43 ... Sacral support part, 50 ... Holding mechanism, 51 ... Engagement piece 52 ... Front plate, 53 ... Engagement bending portion, 54 ... Side plate, 55 ... Contact surface, 56 ... attaching portion, 57 ... upper frame, 58 ... mounting shaft, 60 ... Bracket, 61 ... retracting spring, 62 ... rotation stopper.

Claims (4)

A headrest 6 constituted by providing a pillar 8 on at least a head support portion 7 that supports the head of the seated person is attached to the dorsal frame 3 via the link mechanism L so as to be movable forward, and is located behind the waist of the seated person. The dorsal frame 3 that is positioned is provided with a rear impact detector 25 that senses the backward movement of the seated person due to inertia. The rear impact detector 25 and the link mechanism L of the headrest 6 are located behind the rear impact detector 25. The headrest 6 is moved so as to move forward to be connected so as to support the head of the seated person, and the headrest is moved between the headrest 6 and the dorsal fin frame 3 to a position where the headrest is supported at the time of a rear collision. 6 is provided with an engagement piece 51 that holds the position 6 at the position, and the engagement piece 51 is moved to the rear when the rear-end collision detector 25 is moved so that the headrest 6 moves forward. The inertial force acts on the mass of the engagement piece 51 itself to engage with a part of the link mechanism L or the headrest 6 to hold the headrest 6 moved forward, and the retraction spring 61. Therefore, a rotation stopper that always urges a part of the link mechanism L so as not to engage with the headrest 6 and stops the retraction rotation of the engagement piece 51 at a predetermined position in the vicinity of the engagement piece 51. A vehicle seat provided with 62. In Claim 1, the said engagement piece 51 is made to engage with the headrest attachment rod 10 which fixed the pillar 8 of the headrest 6, and the headrest attachment rod 10 is fixed to the upper link rod 15 provided in the back frame 3. The engagement piece 51 is provided with a contact surface 55 that allows the headrest attachment rod 10 to return, and an engagement bent portion 53 that holds the moving state of the headrest attachment rod 10. A vehicle seat in which the engagement bent portion 53 is formed in a forward downward inclination and the contact surface 55 is formed in a rear downward inclination with reference to a rotation direction toward the headrest mounting rod 10. 3. The engagement piece 51 according to claim 1 or 2, wherein the engagement piece 51 is rotatably attached to a bracket 60 provided on the upper frame 57 of the dorsal frame 3 by an attachment shaft 58, and the engagement piece 51 is attached to the attachment shaft 58. The vehicular seat is provided with the retracting spring 61 for urging the abutment surface 55 so as to retract from the headrest mounting rod 10 and the bracket 60 with the rotation stopper 62. The plate body 31 formed in the shape of a substantially rectangular single plate on the front side of the rear collision detector 25 with respect to the back frame 3 of the back sheet 2 according to claim 1, 2, or 3. The vehicle seat is provided with a plate-like support member 30 that is movably attached to the back and forth, and the upper portion of the plate body 31 is as close as possible to the upper frame 57 of the dorsal frame 3.

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