JP2009179270A - Headrest - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a headrest capable of preventing any erroneous operation in a normal time and in a rear-end collision of a vehicle, and preventing a defective operation when the vehicle is operated. <P>SOLUTION: An inertia weight 96 moving backward of a vehicle with respect to a headrest supporter 10, and a hook member 80 for holding a headrest body 12 at a normal position are arranged on the headrest supporter 10, respectively. The hook member 80 and the inertia weight 96 are connected to each other with a clearance permitting the independent movement of the inertia weight 96 and the hook member 80 backward of the vehicle. Thus, when the inertia weight 96 is moved by a distance over a clearance permitting the independent movement backward of the vehicle from the hook member, the hook member 80 is interlocked therewith, and the headrest body 12 is moved to an emergency position. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a headrest, and more particularly, to a headrest that is disposed in a seat back of a vehicle seat and receives a passenger's head by changing the posture from a normal position to an emergency position at the time of a vehicle collision.

  A headrest is provided above the seat back of the vehicle seat to receive the head of the occupant when the vehicle is bumped from behind. In recent years, various types of movable headrests (also referred to as “active headrests”) with improved protection functions for the head and neck have been proposed. The headrest instantaneously displaces the posture of the headrest body at the time of a vehicle rear-end collision, thereby receiving the head of the occupant. In other words, the movable headrest is configured to displace the headrest body at the normal use position (hereinafter referred to as “normal position”) to a required position (hereinafter referred to as “emergency position”) at the time of vehicle collision. Such a headrest is disclosed in Patent Document 1, for example.

The headrest disclosed in Patent Document 1 is configured by housing each component and member, such as a posture displacing means, a holding means, and a releasing means, in the headrest. Therefore, since the components and members constituting the headrest are not disposed in the seat back, it is possible to avoid an increase in the size of the seat back. In addition, since the components and members that make up the headrest are not separately arranged in the headrest body and the seat back, the components and components are properly connected even if the height of the headrest is adjusted or removed. It is maintained and hardly affects the operation of the headrest.
JP 2001-163101 A

  However, the headrest disclosed in Patent Document 1 is mischievous when, for example, vibrations occur due to sudden acceleration or road surface changes while the vehicle is running, when the seat back angle is changed, when the headrest is attached or detached, or when the height position is adjusted, and when the headrest is hit or shaken. It does not have a function of preventing malfunction of the headrest due to shock or vibration that can act on the headrest at a so-called normal time. In other words, the headrest disclosed in Patent Document 1 may malfunction even when an impact or vibration is applied to the headrest even when the headrest is not in a rear-end collision. Moreover, the headrest of Patent Document 1 is not configured to perform operation control based on the posture state of the seat back. In other words, not only when the seatback is within the normal use range, but also when the seatback is tilted backward or forward, the headrest is actuated at the time of the vehicle rear-end collision. Therefore, for example, even when the occupant is lying down with the seat back tilted backwards or when an article is placed on the headrest body, the headrest is activated at the time of a vehicle collision. Further, even when the headrest is tilted forward and the headrest is in contact with the seat cushion (seat surface), there is a disadvantage that the headrest operates when the vehicle collides.

  On the other hand, the headrest disclosed in Patent Document 1 does not include a return means for returning the headrest body moved to the emergency position to the normal position. For this reason, the headrest operated by the vehicle rear-end collision has a drawback that it cannot be reused because the headrest body cannot be returned to the normal position.

  Accordingly, an object of the present invention is to provide a headrest that prevents malfunction during normal operation and vehicle collision.

In order to solve the above problems and achieve the intended purpose, the invention according to claim 1 of the present application provides:
In a headrest comprising: a support body supported by a seat back of a vehicle seat; and a headrest body connected to the support body through posture displacement means and moving from a normal position to an emergency position at the time of a vehicle collision,
An inertia member disposed on the support and moving relative to the support relative to the support at the time of a vehicle collision;
A holding member that is disposed on the support and normally holds the headrest body in the normal position;
The holding member and the inertia member are linked to each other at a normal position of the headrest body with a clearance that allows the inertia member to move rearward of the vehicle independently of the holding member. The gist is that the holding member is interlocked with the inertia member that moves beyond the amount so that the headrest body is allowed to move to the emergency position.

  Therefore, according to the first aspect of the present invention, when vibration is generated due to sudden acceleration or road surface change while the vehicle is running, when the seat back angle is changed, when the headrest is attached or detached, or when the height position is adjusted, the headrest is hit. Even if the inertia member moves in the vehicle front-rear direction due to impact or vibration acting on the headrest during a so-called mischief, such as a swinging mischief, the inertia member will move within the clearance range at the link between the holding member and the inertia member. The holding member does not interlock. As a result, the headrest does not operate normally, and the headrest can be prevented from malfunctioning.

According to a second aspect of the present invention, there is provided a guide portion that holds the inertia member in a movable manner, and the guide portion that extends in the front-rear direction is provided so as to be swingable on the support so that the guide portion is always in a horizontal state. A balance member;
Located on the rear side of the movement path along the guide portion of the inertia member provided on the support body, the movement of the inertia member to the rear of the vehicle is within the range of the clearance by the amount of angular displacement of the support body in the longitudinal direction of the vehicle. The gist of the present invention is to include a movement restricting unit that restricts the movement to the above.
Therefore, according to the second aspect of the invention, when the angle of the support body in the longitudinal direction of the vehicle is displaced in accordance with the posture of the seat back, the movement of the inertia member is restricted by the movement restricting portion by the amount of displacement. . That is, since the inertia member does not move to the rear of the vehicle beyond the clearance amount described above, the holding member is not displaced and the headrest does not operate. As a result, when the seat back is in the posture of being tilted rearward or forward, the headrest can be prevented from operating even at the time of a vehicle rear-end collision to prevent malfunction of the headrest.

The gist of the invention described in claim 3 is provided with a support member disposed on the support body and biasing the inertia member toward the front of the vehicle.
Therefore, according to the third aspect of the invention, since the inertia member is held by the support member even when an impact or vibration is applied to the headrest at normal times, malfunction of the headrest can be prevented.

According to a fourth aspect of the present invention, the holding member includes a second connecting portion that can be connected to a first connecting portion provided in the headrest body, and the second connecting portion is connected to the first connecting portion to connect the headrest to the headrest. Displaceable between a holding state in which the main body is held in the normal position and a released state in which the connection between the second connecting portion and the first connecting portion is released and the headrest main body is allowed to move to the emergency position. And
When the headrest body that has moved to the emergency position is returned to the normal position, the first connecting portion comes into contact with the second connecting portion of the holding member that is in the released state, and the holding member holds the holding member. The gist of the invention is that the inertia member is positioned at the pre-movement position while being displaced.
Therefore, according to the invention according to claim 4, when the headrest body moved to the emergency position is returned to the normal position after the operation of the headrest, the holding member is displaced to the holding state and the headrest body is held in the normal position. The return operation of the headrest body can be performed easily and quickly. That is, since the headrest body can be returned to the normal position after the operation, it can be reused.

The invention according to claim 5 is a locking portion provided on the holding member;
And a locking member that engages with the locking portion in the holding state of the holding member, and that is disengaged from the locking portion when the inertia member moves relatively rearward of the vehicle. To do.
Therefore, according to the fifth aspect of the present invention, when the holding member is displaced to the holding state, the lock member is engaged with the locking portion, and the headrest body is held at the normal position. When the inertia member moves rearward of the vehicle, the engagement between the lock member and the locking portion is released, the holding member is displaced to the released state, and the headrest body can move to the emergency position.

  According to the headrest of the present invention, it is possible to prevent malfunction during normal times and to prevent malfunction even during a vehicle rear-end collision by restricting the operation by the amount of angular displacement of the support body in the longitudinal direction of the vehicle.

  Next, the headrest according to the present invention will be described below with reference to the accompanying drawings by citing preferred embodiments. In the embodiment, the side that faces the front of the vehicle and receives the head of the passenger (left side in FIG. 1) is referred to as the front side of the headrest HR. Further, the left-right direction of the vehicle is referred to as the left-right direction of the headrest HR, and the left direction is referred to as the left side and the right direction is referred to as the right side when viewed from the front of the vehicle.

  As shown in FIGS. 1 and 2, the headrest HR of the embodiment has a support support 14 that constitutes a headrest support (support) 10 positioned above a stay support member 130 that opens on the upper surface of the seat back S1 in the seat S. Is inserted into the seat back S1. The headrest HR includes a posture displacement mechanism M that moves the headrest main body 12 from the normal position to the emergency position, a holding mechanism D that holds the rotation support member 40 of the posture displacement mechanism M at the normal time, and a rotation by the holding mechanism D during the vehicle rear-end collision. A release mechanism L for releasing the holding of the dynamic support member 40 and a return mechanism T for re-holding the rotation support member 40 by the holding mechanism D are accommodated in the headrest body 12. Further, the headrest HR includes an operation range defining mechanism U for restricting operation at the time of a vehicle rear-end collision, inside the headrest body 12.

  As shown in FIGS. 1 and 2, the headrest HR includes a headrest support 10 that is supported by the seat back S <b> 1 and a headrest body 12 that is disposed on the headrest support 10. The headrest body 12 is connected to the first fixed frame 16 that forms a part of the headrest support 10 via a rotation support member (posture displacement means) 40 of the posture displacement mechanism M. Further, the main body support portion 34 of the headrest main body 12 is disposed so as to be slidable with respect to the support stay 14 constituting the headrest support 10. Therefore, the headrest body 12 slides along the support stay 14 as the rotation support member 40 rotates, and moves while changing its posture from the normal position to the emergency position.

  As shown in FIGS. 1, 2, and 5, the headrest support 10 is fixed to the support stay 14 and a substantially U-shaped support stay 14 formed by bending a pipe material made of steel or the like. A first fixed frame 16 and a second fixed frame 18. The support stay 14 includes a connecting portion 14A that extends horizontally, upper support portions 14B and 14B that are inclined at a required angle toward the rear of the seat back S1 toward the lower side from both left and right ends of the connecting portion 14A, and the upper support portion. The lower support portions 14C and 14C are vertically hung from the lower ends of 14B and 14B and inserted into the stay support member 130 described above. The connecting portion 14 </ b> A contacts the contact surface 46 of the rotation support member 40 when the rotation support member 40 is displaced to a second position (described later), thereby restricting the rotation of the rotation support member 40. . Each of the lower support portions 14C, 14C has four first locking recesses 20 recessed at a required interval in the longitudinal direction of the lower support portion 14C, and locking protrusions (not shown) provided on the stay support member 130. ). Each support stay 14 may be formed of a separate member obtained by bending two pipe members and connected to the first fixed frame 16 and the second fixed frame 18.

  As shown in FIGS. 1 to 6, one second locking recess 22 and three third engagements are provided on the inner side surfaces of the upper support portions 14 </ b> B and 14 </ b> B of the support stay 14, that is, on the inner side of the headrest HR. Stop recesses 23 are formed at required intervals in the longitudinal direction. The second locking recesses 22 and the third locking recesses 23 constitute a reverse prevention mechanism G. Each of the second locking recess 22 and the third locking recess 23 has the same notch shape, but has an inclined surface opposite to that of the first locking recess 20.

  As shown in FIGS. 1 and 5, the first fixed frame 16 fixed to the vicinity of the upper ends of the upper support portions 14 </ b> B and 14 </ b> B is formed by pressing a steel plate having a required outer shape. That is, the first fixed frame 16 includes a flat plate portion 16A extending in parallel with the connecting portion 14A, support portions 16B and 16B which are bent forward from both left and right ends of the flat plate portion 16A and face left and right, and each support portion. It is composed of attachment portions 16C and 16C that are formed in a curved surface at the front ends of 16B and 16B and are fixed to the outer surfaces of the upper support portions 14B and 14B. Each support portion 16B, 16B is provided with a pair of first support holes 24, 24 whose axes are aligned in the left-right direction. A fixed shaft 25 that rotatably supports the rotation support member 40 is inserted and supported in the first support holes 24 and 24. On the flat plate portion 16A, the second arm portions 53, 53 of the main spring 50 are abutted and supported, and a support spring 105 is attached.

  As shown in FIGS. 1 and 5, the second fixed frame 18 fixed to a substantially middle portion of the upper support portions 14 </ b> B and 14 </ b> B is formed by pressing a steel plate having a required outer shape. That is, the second fixed frame 18 is horizontally fixed to the left and right between the upper support portions 14B and 14B, and is bent upward from both left and right ends of the base portion 18A and is fixed to the upper support portion 14B. Mounting portions 18B and 18B, and support portions 18C and 18C extending rearward from the mounting portions 18B and 18B and facing left and right. The base portion 18A has a central portion in the left-right direction that is recessed downward, and a mounting bracket 26 on which the holding mechanism D is disposed is attached. Each of the support portions 18C and 18C is provided with a pair of mounting holes 27 and 27 whose axes are aligned in the lateral direction. The balancer joints 118 and 118 for mounting the balancer (balance member) 110 are mounted in the mounting holes 27 and 27.

  As shown in FIGS. 1 and 2, the headrest body 12 is provided between a headrest core 30 having rigidity, a skin 38 made of genuine leather, synthetic leather, fabric, or the like, and between the headrest core 30 and the skin 38. And a foam 39. The headrest core 30 is a molded part made of synthetic resin that is injection-molded, and includes a front half 31 located on the front side of the headrest HR and a rear half 32 located on the rear side of the headrest HR. The two halves 31, 32 are assembled to form a hollow shape.

  As shown in FIGS. 3 and 6, insertion holes 33 and 33 for inserting the support stay 14 are formed in the bottom wall portions 30 </ b> A and 30 </ b> A of the headrest core 30. Around each insertion hole 33, annular body support portions 34, 34 that move along the upper support portions 14 </ b> B, 14 </ b> B of the support stay 14 are formed. In addition, second support holes 35 and 35 are formed in the vertical wall portions located on the left and right of the front half 31, and a moving shaft (first connecting portion) 36 is inserted and supported in these second support holes 35 and 35. Then, the rotation support member 40 is rotatably supported.

  As shown in FIGS. 1, 5 and 6, the rotation support member 40 constituting the posture displacement mechanism M is a horizontally long single member formed by injection molding a synthetic resin material. And even if it receives the impact force at the time of a passenger | crew's head colliding with headrest HR, the intensity | strength and rigidity which are not deformed or damaged are provided. Further, in a posture in which the rotation support member 40 is housed inside the headrest support 10 (see FIGS. 2 and 6), the left and right sides of the wall portion serving as the upper surface of the rotation support member 40 are in an ear shape. A pair of support portions 41, 41 are provided so as to project. The first support holes 41 and 41 are respectively provided with first through holes 42 and 42 through which the above-described fixing shaft 25 is inserted so that the horizontal axes coincide with each other. Accordingly, the rotation support member 40 is pivotally supported on the first fixed frame 16 by the fixed shaft 25 inserted through the first through holes 42 and 42. As a result, the rotation support member 40 is approximately about the first position (FIG. 2, FIG. 12A) accommodated in the lower front of the first fixed frame 16 and the first fixed frame 16 with the fixed shaft 25 as the center. It is possible to rotate between a second position (FIGS. 1 and 12B) that rotates 90 degrees and protrudes forward. When the rotation support member 40 is in the first position, the headrest HR is held in the normal position (FIG. 2), and when the rotation support member 40 is moved to the second position, the headrest HR is in the emergency position. Move (Figure 1).

  As shown in FIG. 5, a pair of boss portions 43, 43 are formed on the front surfaces on both sides of the lower portion of the rotation support member 40. Both boss portions 43 and 43 are provided with second through holes 44 through which the above-described moving shaft 36 is inserted. The rotation support member 40 is pivotally supported on the front half body 31 of the headrest core 30 via a moving shaft 36 inserted through the second through hole 44 so that the rotation support member 40 can rotate with respect to the headrest body 12. The movable shaft 36 is disposed with a required inter-axis distance from the fixed shaft 25. When the rotation support member 40 is in the first position as shown in FIGS. Located below. Further, as shown in FIGS. 1 and 12 (b), the moving shaft 36 follows an arc locus centered on the fixed shaft 25 when the rotation support member 40 rotates from the first position to the second position. Move forward and upward. As shown in FIG. 1, the moving shaft 36 is positioned substantially in front of the fixed shaft 25 when the rotation support member 40 reaches the second position.

  As shown in FIGS. 2 and 6, a projecting portion 45 extending in the left-right direction protrudes from the front surface portion of the rotation support member 40 in the first position, and the upper surface of the projecting portion 45 is a contact surface 46. It is configured as. As shown in FIG. 1, when the rotational support member 40 is displaced to the second position, the projecting portion 45 comes into contact with the connecting portion 14A of the support stay 14, and the contact surface 46 comes into contact with the connecting portion 14A. The rotation support member 40 is contacted, and the rotation of the rotation support member 40 from the second position is restricted, and the impact caused by the collision of the head of the occupant with the headrest body 12 is received.

  As shown in FIGS. 1, 2, 5, and 6, a double torsion spring type main spring 50 that rotates the rotation support member 40 from the first position to the second position is disposed on the fixed shaft 25. Has been. When the main spring 50 is in an unloaded state, as shown by a two-dot chain line in FIG. 5, the central first arm portion 52 that connects the twisted portions 51, 51 extends from the ends of the twisted portions 51, 51. With respect to the second arm portions 53 and 53 that have come out, the posture is expanded to 90 degrees or more, and the first arm portion 52 is deformed to a position directed vertically downward as shown by a solid line in FIG. The main spring 50 is interposed between the support portions 41 and 41 of the rotation support member 40 and the fixed shaft 25 via spacers 54 and 54 inserted into the twisted portions 51 and 51. As shown in FIGS. 2 and 6, the first arm portion 52 is inserted into the opening 47 formed in the rotation support member 40 and contacts the inner contact portion 48 of the rotation support member 40.

  As shown in FIGS. 1 and 2, the rotation support member 40 attached to the first fixed frame 16 via the fixed shaft 25 has each second arm portion 53 of the main spring 50 as a flat plate of the first fixed frame 16. Since it comes into contact with the portion 16A from the front, it is held in a state of being elastically biased to the second position. Therefore, when the rotation support member 40 located at the second position is moved to the first position, the first arm portion 52 of the main spring 50 is displaced to the position indicated by the solid line in FIG. The maximum elasticity.

  The headrest HR of the embodiment is provided with a reverse prevention mechanism G that restricts the headrest body 12 from returning to the normal position when the headrest body 12 moves from the normal position to the emergency position. As shown in FIGS. 3, 4, and 7, the reverse prevention mechanism G is provided on the lock plates 60 and 60 provided on the outer bottom surface of the headrest body 12 and the upper support portions 14 </ b> B and 14 </ b> B of the support stay 14. The second locking recess 22 and the third locking recess 23 are configured as described above.

  As shown in FIGS. 4 and 7, each lock plate 60 is a rectangular frame made of metal (steel or stainless steel or the like) and is a plate of each bracket 66, 66 fixed to the outer bottom surface of the headrest body 12. The mounting portion 68 is slidably mounted. At one inner end edge portion in the opening portion of each lock plate 60, an edge locking portion 61 that contacts the upper support portion 14B inserted through the opening portion is formed. In addition, an operation portion 62 for slide operation is provided on the outer edge portion of each lock plate 60 on the side opposite to the portion where the edge lock portion 61 is formed. Further, a latch pin 63 for latching the compression coil spring 64 is projected from the outer end edge portion of the lock plate 60 where the end edge locking portion 61 is formed. The bracket 66 defines a plate arrangement portion 68 and has a member main body 67 in which a stay support hole 67A is formed, and a locking claw that enters and locks into a locking hole 30B formed in the bottom wall portion 30A of the headrest core 30. Part 69.

  As shown in FIGS. 3 and 4, the second locking recess 22 is provided at a position where locking by the lock plate 60 is performed when the headrest body 12 is displaced to the emergency position. The locking step portion 22A positioned on the side of the stay 23 and substantially perpendicular to the outer surface of the stay, and located on the second fixing frame 18 side from the bottom side of the locking step portion 22A toward the second fixing frame 18 It has the inclined part 22B which inclines. On the other hand, each of the third locking recesses 23 is positioned closer to the distal end side of the support stay 14 than the second locking recess 22 and is substantially perpendicular to the outer surface of the stay, and the second locking recess 22 An inclined portion 23B that is located on the side and is inclined from the bottom side of the locking step portion 23A toward the second locking recess 22 is provided. Therefore, when the lock plate 60 elastically biased toward the support stay 14 moves from the lower side (the tip side of the support stay 14) to the upper side (the second fixed frame 18 side), the edge locking portion 61 is moved. The headrest main body 12 is allowed to move from the normal position toward the emergency position by slidingly contacting the inclined portion 23B of each third locking recess 23. On the other hand, when the lock plate 60 elastically biased toward the support stay 14 moves from the upper side (the second locking recess 22 side) to the lower side (the tip side of the support stay 14), the edge locking portion 61 is moved. Is locked to the locking step portions 22A and 23A of the second locking recess 22 or the third locking recess 23, and the return of the headrest body 12 to the normal position side is restricted.

  The reverse rotation prevention mechanism G of the embodiment can release the locking between the lock plate 60 and the second locking recess 22 without using a separate reset tool. That is, when the operation portion 62 exposed from the bracket 66 is pushed toward the support stay 14 with the fingertip, the edge locking portion 61 is separated from the second locking recess 22 of the support stay 14 and these edge locking The locking between the portion 61 and the second locking recess 22 is released. Accordingly, when the headrest body 12 is pushed back toward the normal position while the operation portions 62 of the lock plates 60 and 60 are simultaneously pressed with the fingertips, the headrest body 12 is allowed to return to the normal position.

  As shown in FIGS. 2, 6, and 8, the holding mechanism D that holds the rotation support member 40 in the first position in the normal state is located at the position where the headrest body 10 is located inside the headrest body 12. 2 The mounting bracket 26 is fixed to the fixed frame 18. The mounting bracket 26 has a first side wall portion 70 and a second side wall portion 71 that are spaced apart from each other in the left-right direction of the headrest HR, and the holding mechanism D is interposed between the first side wall portion 70 and the second side wall portion 71. And the connecting arm member 90 are disposed. In the vicinity of the front end of the first side wall 70 and the vicinity of the front end of the second side wall 71, first through holes 72 and 72 having through-holes are formed to pivotally support the hook member (holding member) 80 of the holding mechanism D. The hook shaft 78 is inserted and supported in the first support holes 72 and 72. In addition, second support holes 73 and 73 having through-holes are formed behind the first support holes 72 and 72 of the first side wall part 70 and the second side wall part 71 described above, and constitute a holding mechanism D. The pin 81 is inserted into and supported by the second support holes 73 and 73 so as to be slidable. These 2nd support holes 73 and 73 are formed in the back-up inclination shape. Furthermore, stopper holes 74 and 74 through which the weight shaft 97 is inserted loosely are formed in portions extending rearward from the first side wall 70 and the second side wall 71.

  As shown in FIGS. 8A and 8B, the holding mechanism D rotates around a hook shaft 78 that is installed on the first side wall 70 and the second side wall 71 below the rotation support member 40. A hook member 80 that is movably attached, a lock pin 81 that restricts rotation of the hook member 80, and a hook spring 82 that imparts a rotational force to the hook member 80 are provided. The hook member 80 is a plate-shaped molded member made of metal or reinforced resin, and has a strength capable of holding the rotation support member 40 biased toward the second position by the main spring 50 at the first position. Stiffness is given. A pivot hole 83 is formed below the front part of the hook member 80, and the hook shaft 78 is inserted therethrough. Therefore, the hook member 80 is pivotally supported by the mounting bracket 26 in a vertically standing state by the hook shaft 78 inserted through the pivot support hole 83. Thus, the hook member 80 is held between the first side wall 70 and the second side wall 71 of the mounting bracket 26 (FIGS. 2 and 12A), and the mounting bracket 26 with the hook shaft 78 as the center. With respect to the release state (FIGS. 1 and 12 (b)), it rotates about 45 degrees to the front. Then, the rotation support member 40 is held at the first position while the hook member 80 is held, and the rotation support member 40 is allowed to be displaced to the second position when the hook member 80 is released.

  As shown in FIGS. 2 and 11, an engaging recess (second connecting portion) 84 that opens vertically upward is formed in the upper portion of the hook member 80 in a holding state. The engaging recess 84 is aligned with the moving shaft (first connecting portion) 36 exposed between the boss portions 43, 43 of the rotation support member 40 in the first position in the holding state of the hook member 80. Further, as shown in FIG. 12B, the engagement recess 84 is the movement locus direction of the moving shaft 36 when the rotation support member 40 rotates toward the second position in the released state of the hook member 80. Orient the front and upper direction. Therefore, when the hook member 80 is rotated and displaced from the holding state to the released state, the connection between the hook member 80 and the moving shaft 36 (the rotation support member 40) is released.

  Further, as shown in FIG. 11, the hook member 80 is formed with a locking cam groove 85 that allows the locking pin 81 to be inserted behind the pivotal support hole 83. The locking cam groove 85 includes an arc portion 85A having the pivot support hole 83 as an arc center, and a locking portion 85B extending forward from the upper end of the arc portion 85A. As shown in FIGS. 12 (a) and 12 (b), the arc portion 85A has a rear end portion of each second support hole 73 described above when the hook member 80 is displaced between the holding state and the released state. And on the straight line in the horizontal direction. On the other hand, as shown in FIGS. 11 (a) and 11 (b), the locking portion 85B coincides with the second support holes 73 and 73 on the straight line in the left-right direction when the hook member 80 is held.

  Therefore, both ends of the lock pin 81 are inserted and supported by the second support holes 73 and 73 of the mounting bracket 26 in a state where the lock pin 81 penetrates the locking cam groove 85 of the hook member 80 in the left-right direction. The lock pin 81 can slide between the front and rear ends of the second support holes 73 and 73 and between the front and rear ends of the locking portion 85 </ b> B in the locking cam groove 85 in the holding state of the hook member 80. When the lock pin 81 is located at the front end of each of the second support holes 73, 73, the intermediate portion of the lock pin 81 is located at the front end of the locking portion 85B, and the hook member 80 is displaced toward the released state. To be regulated. On the other hand, when the lock pin 81 is positioned at the rear end of each second locking hole 73, 73, the intermediate portion of the lock pin 81 is aligned with the upper end of the arc portion 85 </ b> A of the locking cam groove 85. Accordingly, when the hook member 80 rotates toward the released state, the intermediate portion of the lock pin 81 moves relatively along the arc portion 85A, so that the hook member 80 is allowed to be displaced toward the released state. The

  The hook member 80 is urged so as to be always displaced to a released state by a torsion spring type hook spring 82 externally mounted on the hook shaft 78. That is, one leg portion of the hook spring 82 is locked to the mounting bracket 26, and the other leg portion is locked to the front upper portion of the hook member 80. Therefore, when the rotation support member 40 is in the first position, the hook member 80 is held in the holding state by the lock pin 81 engaging with the engaging portion 85B, and the rotation support member 40 is held in the first position. Hold in position. When the lock pin 81 slides backward and moves to the upper end of the arc portion 85A, the hook member 80 is attached to the hook spring 82 as the engagement between the locking portion 85B and the lock pin 81 is released. It is turned toward the released state by the force. Reference numeral 79 in FIG. 8 denotes a spacer that is externally mounted on the hook shaft 78, and the hook member 80 is pivotally supported by the hook shaft 78 while being sandwiched between the spacer 79 and the hook spring 82.

  As shown in FIG. 1 and FIG. 8, the release mechanism L that moves the lock pin 81 rearward at the time of a vehicle collision and allows the hook member 80 held in the holding state to be displaced to the released state is provided as a headrest support. 10 is disposed on a mounting bracket 26 fixed to the second fixed frame 18 at a portion located inside the headrest body 12. The release mechanism L includes a connecting arm member 90 connected to the lock pin 81 behind the holding mechanism D, and inertia weights (inertial members) 96 and 96 connected to the connecting arm member 90. That is, the lock pin 81 is linked to the inertia weights 96, 96 via the connecting arm member 90 and the weight shaft 97. The connecting arm member 90 is a molded member made of metal or reinforced resin, and connects the first arm 91 and the second arm 92 that are separated from each other in the left-right direction and extend in parallel in the front-rear direction, and both arms 91 and 92. Connecting portion 93 to be connected. A first connection hole 94 through which the lock pin 81 is inserted is formed in the front end portions of the first arm 91 and the second arm 92 so as to be aligned in the left-right direction. These first connection holes 94, 94 have a through-hole shape having the same inner diameter as the outer diameter of the lock pin 81, and the connection arm member 90 and the lock pin 81 are not loose. Are connected to each other.

  Further, as shown in FIGS. 9 and 11, the second connecting hole 95 through which the above-described weight shaft 97 provided in the inertia weight 96 is inserted in the rear end portions of the first arm 91 and the second arm 92. It is formed so as to be aligned in the direction. These second connection holes 95 and 95 have a through-hole shape with a required length extending along the longitudinal direction of the respective arms 91 and 92, and the weight shaft 97 extends along the second connection holes 95 and 95. It can slide. That is, the connecting arm member 90 connected to the hook member 80 and the weight shaft 97 provided to the inertia weight 96 are linked with a clearance that allows the inertia weight 96 to move rearward of the vehicle independently of the hook member 80. Has been.

  As shown in FIGS. 8 to 11, each of the inertia weights 96, 96 is attached with a weight shaft 97 inserted into each of the second connection holes 95, 95 of the connection arm member 90, and is rotatable on the second fixed frame 18. It is accommodated in the balancer 110 attached to the. The balancer 110 is formed with a total of four partition walls 115 that are spaced apart from each other at a required interval in the left-right direction, and each partition wall 115 has a guide hole (guide portion) 119 having a through-hole shape extending in the front-rear direction. Is formed. In other words, the inertia weights 96 and 96 are accommodated in the accommodating portions 116 and 116 formed between the partition walls 115 and 115 in a state where the inertia weights 96 and 96 are connected to the weight shaft 97 inserted into the guide holes 119. The weight shaft 97 can slide in the front-rear direction of the balancer 110 along the guide hole 119, and the inertia weights 96, 96 can move in the front-rear direction in the housing portions 116, 116. Yes. Each of the inertia weights 96 is set to a weight that moves relative to the rear of the vehicle by inertial force with respect to the headrest support 10 and the balancer 110 that move forward together with the headrest HR when the vehicle collides.

  The clearance between the second connecting holes 95, 95 of the connecting arm member 90 connected to the hook member 80 and the weight shaft 97 provided in the inertia weight 96 is an inertia caused by an impact or vibration acting on the headrest HR in a normal state. The weight 96 is set to allow the movement of the weight 96 toward the rear of the vehicle. In other words, the inertia weight 96 moves in the event of vibrations due to sudden acceleration or road changes during vehicle travel, when the seatback angle is changed, when the headrest is attached / detached or when the height position is adjusted, and when the headrest is hit or shaken. In this case, the weight shaft 97 only moves along the second connection holes 95, 95, and the connection arm member 90 does not move. As a result, the headrest HR of the embodiment does not operate even when an impact or vibration is applied during normal operation, and prevents malfunction during normal operation.

  On the other hand, as shown in FIG. 11 (b), when the headrest HR moves forward during the vehicle rear-end collision, each of the inertia weights 96, 96 has the above-described weight shaft 97 and the second weight with respect to the headrest support 10 that moves forward. It moves relative to the rear of the vehicle beyond the amount of clearance at the connecting portion with the connecting holes 95, 95. Accordingly, the weight shafts 97 inserted into the second connection holes 95 and 95 move rearward along the guide holes 119 and come into contact with the rear ends of the second connection holes 95 and 95 during the movement. As a result, as shown in FIG. 12A, the connecting arm member 90 moves rearward following the movement of the inertia weights 96, 96, and the lock pin 81 connected to the connecting arm member 90 has the second support. Since it slides back along the holes 73, 73, the engagement between the lock pin 81 and the engaging portion 85B of the hook member 80 is released. Accordingly, as shown in FIG. 12B, the hook member 80 held in the holding state is displaced to the released state by the urging force of the hook spring 82 and is connected to the hook member 80. The rotational support member 40 is displaced from the first position to the second position by the urging force of the main spring 50.

  As shown in FIGS. 1, 8, and 9, when the headrest body 12 is returned from the emergency position to the normal position, the return mechanism T that reconnects the hook member 80 that has returned to the holding position and the lock pin 81 is provided. The headrest support 10 is disposed on the first fixed frame 16 at a portion located inside the headrest body 12. The return mechanism T is disposed on a lever-shaped support arm (support member) 100 pivotally supported by a fixed shaft 25 attached to the first fixed frame 16 and a flat plate portion 16A of the first fixed frame 16 so as to be supported by the support arm. And a support spring 105 that elastically contacts 100 from the rear.

  As shown in FIGS. 5, 6, and 9, a boss 101 having a width dimension substantially the same as the distance between the spacers 54 and 54 attached to the fixed shaft 25 is formed at the upper end of the support arm 100. Yes. The boss portion 101 is formed with a pivot hole 101 </ b> A through which the fixed shaft 25 is inserted in the left and right direction so as to penetrate the boss portion 101 in the left and right direction. Further, the lower end portion of the support arm 100 is formed with a curved support portion 102 that extends rearward and downward and hangs down between the rear ends of the first arm 91 and the second arm 92 of the connecting arm member 90. The support portion 102 is formed with a support hole 102 </ b> A through which the weight shaft 97 is inserted in the left and right direction so as to penetrate the support portion 102 in the left and right direction. Such a support arm 100 is pivotally supported between the spacers 54 and 54 without rattling with respect to the fixed shaft 25, and rotates so that the support portion 102 moves in the front-rear direction. The opening portions on both sides of the support hole 102A of the support portion 102 are aligned with the second connection holes 95, 95 formed in the first arm 91 and the second arm 92, and the weight shaft 97 is inserted into the support hole 102A. Yes. Therefore, the weight shaft 97 inserted through the support hole 102A is allowed to move in the longitudinal direction of the support arm 100 (up and down direction of the headrest HR) with respect to the support arm 100, and the thickness direction of the support arm 100 (headrest). It is connected to the support arm 100 with no backlash in the HR front-rear direction. Thereby, even if it is the structure provided with the two inertia weights 96,96, both inertia weights 96,96 do not carry out the diagonal attitude | position displacement in the front-back direction in each accommodating part 116,116 of the balancer 110, and both. The inertia weights 96 and 96 are always held in parallel with the balancer 110.

  As shown in FIG. 11, the support spring 105 is a plate spring including an attachment portion 106 that is locked to the flat plate portion 16 </ b> A of the first fixed frame 16 and an abutting portion 107 that abuts against the intermediate portion of the rear surface of the support arm 100. The support arm 100 is always urged forward while being attached to the flat plate portion 16A. The support spring 105 urges the inertia weight 96 forward of the vehicle with a biasing force that is weaker than the force by which the inertia weight 96 moves rearward of the vehicle at the time of a vehicle rear-end collision. Therefore, when the inertia weight 96 moves rearward of the vehicle, the support arm 100 rotates rearward against the urging force of the support spring 105 to allow the inertia weight 96 to move. Is done.

  In a normal state, the weight shaft 97 is held by the support arm 100 urged by the support spring 105, so that the inertia weight 96 attached to the weight shaft 97 is held at the pre-movement position. Further, the connecting arm member 90 connected to the weight shaft 97 is held forward, and the locking portion 85B of the hook member 80 and the lock pin 81 are held in an engaged state. That is, since the support arm 100 urged by the support spring 105 holds the weight shaft 97, rattling of the inertia weight 96 due to impact or vibration is prevented, and the hook member 80 is held in the holding posture.

  Then, when releasing the above-described reversion preventing mechanism G and returning the headrest body 12 from the emergency position to the normal position, as shown in FIG. 13A, the rotation support member 40 is moved from the second position to the first position. Immediately before returning to the position, the moving shaft 36 is fitted into the locking recess 84 of the hook member 80. Further, as shown in FIG. 13B, when the headrest body 12 is pushed beyond the normal position, the second support holes 73 and 73 and the locking portion 85B of the locking cam groove 85 are aligned in the left-right direction. The support arm 100 is pushed forward by the urging force of the support spring 105, and the connecting arm member 90 moves forward. Therefore, the lock pin 81 is engaged with the locking portion 85B of the locking cam groove 85 formed in the hook member 80, and the hook member 80 and the lock pin 81 are reconnected. Then, when the push-back with respect to the headrest body 12 is released, the rotation support member 40 is held at the first position by the hook member 80 held in the holding posture by the lock pin 81.

  The weight shaft 97 and each of the second connecting holes 95 and 95 are connected to each other with the above-described clearance, and the weight shaft 97 is normally second by the support arm 100 biased by the support spring 105. Since it is located at the front end of the connection holes 95, 95, there are the following advantages. That is, at the time of the rear-end collision, the inertia weights 96, 96 are not loaded until the inertia weights 96, 96 are moved rearward from the front holding position by the amount of clearance. The movement starts smoothly. In addition, in a state where the inertia weights 96, 96 are moving while accelerating toward the rear of the vehicle, the weight shaft 97 comes into contact with the rear ends of the second connection holes 95, 95 so that the connection arm member 90 is thereby contacted. As a result, the engagement portion 85B of the engagement cam groove 85 and the lock pin 81 can be reliably released.

  Further, as shown in FIGS. 8 and 15, an operation range defining mechanism U that allows the release mechanism L to be operated by the movement of the inertia weight 96 when the posture of the headrest main body 12 is in a required angle range includes a headrest support body. 10 is disposed on the second fixed frame 18 at a portion located inside the headrest body 12. The operation range defining mechanism U is disposed between the support portions 18C and 18C of the second fixed frame 18 and can be swung so that the guide hole 119 extending in the front-rear direction of the vehicle is always horizontal. And stopper holes 74, 74 provided in the rear side portions of the first side wall 70 and the second side wall 71 of the mounting bracket 26. Specifically, as shown in FIG. 18, when the inclination angle of the seat back S1 with respect to the horizontal front is a so-called normal use range between the forward tilt limit angle R1 and the rear tilt limit angle R2. The operation of the headrest HR during the vehicle rear-end collision is allowed. Further, when the inclination angle of the seat back S1 with respect to the horizontal front is smaller than the forward tilt limit angle R1 (forward tilt posture) or larger than the rear tilt limit angle R2 (back tilt posture). Is configured such that the operation of the headrest HR is restricted even during a vehicle rear-end collision. The normal use range here is set in consideration of the inclination angle range of the seat back S1 when the occupant is normally seated, and the uphill and downhill roads. That is, the forward tilt angle R1 of the seat back S1 assumes a case where the seat back S1 is moved forward as much as possible in a normal sitting posture and the vehicle is lowered forward. Further, the rearward inclination angle R2 of the seat back S1 is assumed to be a case where the seat back S1 is moved to the maximum backward in a normal seating posture and the vehicle is lifted forward.

  The balancer 110 has a concave portion 111 at the center for avoiding interference with the mounting bracket 26 and the support arm 100 described above, and is divided into a first portion 113 and a second portion 114 via a connecting wall portion 112. The first portion 113 and the second portion 114 are formed with the above-described partition walls 115 and 115 that are separated in the left-right direction, and a storage portion 116 that stores the inertia weight 96 between the opposing partition walls 115 and 115. It is defined. Balancer shafts 117 and 117 are formed on the same axis on the left and right side walls of the balancer 110. The positions where the balancer shafts 117 and 117 are formed coincide with the center of gravity of the balancer 110 in the front-rear direction and are biased upward in the vertical direction. Then, the balancer joints 118 and 118 that are rotatably mounted on the balancer shafts 117 and 117 are fitted and mounted in the mounting holes 27 and 27 provided in the support portions 18C and 18C of the second fixed frame 18, respectively. 110 is rotatably attached to the second fixed frame 18. As a result, the balancer 110 is weight-balanced in the front-rear direction, and is always maintained in a horizontal state even when the posture of the headrest support 10 changes in the front-rear direction.

  As shown in FIGS. 10 and 15, each of the aforementioned guide holes 119 provided in each partition wall 115 of the balancer 110 is formed to extend horizontally in the vehicle front-rear direction in the horizontal posture of the balancer 110. . Accordingly, the inertia weights 96, 96 fixed to the weight shaft 97 inserted through the respective guide holes 119 can be moved rearward in the horizontal direction since the balancer 110 is always held in a horizontal posture.

  As shown in FIG. 15, the stopper holes 74 and 74 provided in the first side wall portion 70 and the second side wall portion 71 of the mounting bracket 26 are inserted with the weight shaft 97 in a loosely fitted state, and the support arm 100 guides the guide hole 119. A circular movement restricting portion 121 centered on the axial center of the weight shaft 97 held at the front end of the weight shaft and having a radius equal to or smaller than the clearance amount described above, and a fan-shaped portion formed on the rear edge side of the movement restricting portion 121. The fan-shaped part 122 is comprised. An upper projecting corner portion 123 and a lower projecting corner portion 124 projecting inward of the opening are formed at the upper and lower boundary portions between the movement restricting portion 121 and the fan-shaped portion 122.

  15 and 18, when the seat back S1 is in the standard use position, the guide holes 119 extending horizontally to the balancer 110 face the fan-shaped portions 122 of the stopper holes 74 and 74, respectively. The movement restricting portion 121 described above is not located on the rear side of the movement path along the guide hole 119 of the weight shaft 97. Accordingly, the weight shaft 97 provided on the inertia weight 96 is allowed to move rearward along the guide hole 119, and the headrest HR can be operated as described above.

  Further, as shown in FIGS. 16A and 18, when the inclination angle of the seat back S1 becomes the rearward inclination limit angle R2, the mounting bracket 26 is in the rearward inclination state shown in FIG. However, the guide hole 119 extending horizontally to the balancer 110 faces the fan-shaped portion 122 of each stopper hole 74, 74. That is, the movement restricting portion 121 is not located on the rear side of the movement path along the guide hole 119 of the weight shaft 97. Accordingly, the weight shaft 97 provided on the inertia weight 96 is allowed to move rearward along the guide hole 119, and the headrest HR can be operated as described above.

  However, as shown in FIG. 16B and FIG. 18, when the inclination angle of the seat back S1 is larger than the rearward inclination limit angle R2, the rear inclination angle of the mounting bracket 26 is further increased. The horizontally extending guide hole 119 does not face the fan-shaped portion 122 of each stopper hole 74, 74. That is, the upper projecting angle portion 123 protrudes to the rear side of the movement path along the guide hole 119 of the weight shaft 97, and the movement restriction portion 121 is positioned to the rear side of the movement path along the guide hole 119 of the weight shaft 97. Become. Therefore, the weight shaft 97 provided on the inertia weight 96 is restricted from moving rearward beyond the clearance amount by contacting the movement restricting portion 121, and the headrest HR cannot be operated.

  On the other hand, as shown in FIGS. 17 (a) and 18, when the inclination angle of the seat back S1 becomes the forward inclination limit angle R1, the mounting bracket 26 is in the forward inclination state shown in FIG. 17 (a). However, the guide hole 119 extending horizontally to the balancer 110 faces the fan-shaped portion 122 of each stopper hole 74, 74. That is, the movement restricting portion 121 is not located on the rear side of the movement path along the guide hole 119 of the weight shaft 97. Accordingly, the weight shaft 97 provided on the inertia weight 96 is allowed to move rearward along the guide hole 119, and the headrest HR can be operated as described above.

  However, as shown in FIG. 17B and FIG. 18, when the inclination angle of the seat back S1 becomes smaller than the forward inclination limit angle R1, the front inclination angle of the mounting bracket 26 becomes further larger. The horizontally extending guide holes 119 do not face the fan-shaped portions of the stopper holes 74 and 74. That is, the lower projecting angle portion 124 protrudes to the rear side of the movement path along the guide hole 119 of the weight shaft 97, and the movement restriction portion 121 is positioned to the rear side of the movement path along the guide hole 119 of the weight shaft 97. Become. Therefore, the weight shaft 97 provided on the inertia weight 96 is restricted from moving rearward beyond the clearance amount by contacting the movement restricting portion 121, and the headrest HR cannot be operated.

  Therefore, the working range defining mechanism L of the embodiment changes the setting of the diameter of the movement restricting portion 121 and the opening angle V of the fan-shaped portion 122 in the stopper hole 74 as shown in FIG. 123 and the shape of the lower projecting angle portion 124 can be changed to adjust the operating range of the headrest HR with respect to the inclination angle of the seat back S1 shown in FIG. Note that when the upward spread angle V1 with respect to the horizontal axis of the fan-shaped portion 122 is adjusted, the rearward tilt limit angle R2 is changed, and the operating range on the rearward tilt side of the seat back S1 can be increased or decreased. Similarly, when the downward expansion angle V2 with respect to the horizontal axis of the fan-shaped portion 122 is adjusted, the forward tilt limit angle R1 is changed, and the operating range on the forward tilt side of the seat back S1 can be increased or decreased.

  Therefore, according to the headrest HR of the embodiment configured as described above, the following operational effects can be obtained. First, in the headrest HR of the embodiment, the hook member 80 and the inertia weight 96, that is, the connecting arm member 90 connected to the hook member 80 and the weight shaft 97 provided on the inertia weight 96 are independent of the hook member 80 and the inertia weight. Since the clearance is provided to allow the 96 to move rearward of the vehicle, the malfunction is prevented during normal operation. That is, when a vibration occurs due to sudden acceleration or road surface change while the vehicle is running, when the angle of the seat back S1 is changed, when the headrest HR is attached or detached, or when the height position is adjusted, and when a mischief occurs when the headrest HR is hit or shaken, so-called normal Even when the inertia weight 96 moves rearward due to an impact or vibration acting on the headrest HR, the headrest HR does not operate. Further, since the weight shaft 97 is held by the support arm 100, even if vibration or impact acts on the headrest HR, it is possible to reliably prevent malfunction and to prevent the inertia weight 96 from rattling.

  And, when the seat back S1 is in the normal use range, the headrest HR is operated by the operation range defining mechanism U provided in the headrest body 12, and the seat back S1 is in a position outside the normal use range. In this case, the headrest HR does not operate even during the vehicle rear-end collision. That is, when the seat back S1 is in the normal use range, the operation of the release mechanism L is permitted by the operation range defining mechanism U, the holding mechanism D and the attitude displacement mechanism M are operated, and the headrest HR is operated. As a result, the headrest body 12 is displaced from the normal position to the emergency position, so that the head of the passenger sitting on the seat S can be received. And since the headrest main body 12 does not return in the direction of the normal position by the return prevention mechanism G, the occupant's head can be properly received.

  On the other hand, when the seat back S1 is tilted forward from the normal use range, the operation of the release mechanism L is restricted by the operation range defining mechanism U, and the malfunction of the headrest HR is prevented. Furthermore, even when the seat back S1 is tilted backward from the normal use range, the operation of the release mechanism L is restricted by the operation range defining mechanism U, and the malfunction of the headrest HR is prevented. Thereby, for example, when the occupant is lying down with the seat back S1 lying backward, the headrest HR does not operate even at the time of a vehicle rear-end collision, so the occupant's head is strongly pushed upward. There is no inconvenience. Further, when the article is placed on the headrest main body 12 with the seat back S1 lying in the rearward direction, the headrest HR does not operate even during a vehicle rear-end collision, so that the article is prevented from being thrown away. . Further, when the seat back S1 is laid forward and the headrest HR is in contact with the seat cushion, the headrest HR does not move even at the time of a vehicle rear-end collision. Damage can be prevented.

  Then, the headrest body 12 whose posture is displaced from the normal position to the emergency position is released by the return mechanism T and the holding mechanism when the headrest body 12 is simply pushed into the normal position while the reverse prevention mechanism G is released. D is reconnected and the headrest body 12 can be held in its normal position and can be reused after activation. In addition, when the headrest body 12 is returned from the emergency position to the normal position, a separate reset tool is not required, so that the return operation for returning the headrest body 12 to the normal position can be performed easily and quickly.

  Further, the headrest HR of the embodiment includes a posture displacement mechanism M including a rotation support member 40, a holding mechanism D including a hook member 80, a release mechanism L including an inertia weight 96, a return mechanism T including a support arm 100, and a balancer 110. In addition, all the members and parts constituting the headrest HR such as the operation range defining mechanism U including the movement restricting portion 121 are accommodated in the headrest main body 12. Therefore, since the constituent members and parts of the headrest HR are not disposed in the seat back S1, it is possible to prevent the seat back S1 from becoming large and feeling of use. Further, since all the constituent members and parts are arranged in the headrest body 12, even if the headrest HR is attached to or detached from the seat back S1 or the height of the headrest HR is adjusted, the connection of the constituent members is poor. In this way, malfunction of the headrest HR can be prevented.

(Example of change)
In the above-described embodiment, as the posture displacement mechanism M that moves the headrest body 12 from the normal position to the emergency position, the rotation support member 40 pivotally supported by the headrest support 10 and the headrest core 30 is illustrated. did. However, the posture displacement mechanism M only needs to be able to displace the headrest body 12 from the normal position to the emergency position. For example, the posture displacement mechanism M may be configured by a link mechanism, a slide mechanism, or the like.

  The operating range defining mechanism U is not limited to the embodiment in which the balancer 110 is a main body, and may be in any other form as long as the posture of the seat back S1 can be detected. For example, detection means such as an angle detection sensor or an inclination sensor may be used.

  The movement restricting portion 121 in the operation range defining mechanism U is not limited to the one formed by the stopper holes 74 and 74 provided in the mounting bracket 26, and the weight shaft 97 is accompanied by the angular displacement of the headrest support 10 in the front-rear direction of the vehicle. As long as it is located on the rear side of the movement path along the guide hole 119 and can restrict the movement of the weight shaft 97 toward the rear of the vehicle, other forms may be used. For example, a slide member or the like that extends to the rear side of the moving path of the weight shaft 97 may be provided in accordance with the angular displacement of the headrest support 10.

  The holding mechanism D is not limited to the form of the embodiment with the rotation type hook member 80 as a main body, and any other form can be used as long as it can hold the rotation support member 40 of the posture displacement mechanism M in the first position. It may be. For example, the mounting bracket 26 may be configured to slide or protrude.

  The support spring 105 of the return mechanism T is not limited to the form shown in the embodiment, and may be a coil spring, a torsion spring, or the like as long as it can bias the support arm 100. Further, the support arm 100 is not limited to the one that supports the weight shaft 97 provided on the inertia weight 96, and may support the inertia weight 96 directly.

  In the embodiment, the hook member 80 and the weight shaft 97 are connected via the connecting arm member 90. However, the hook member 80 and the weight shaft 97 may be linked directly. . In this case, the weight shaft 97 has the function of the lock pin 81 together.

  A headrest according to the present invention is a movable headrest that is disposed on a seat back of a seat installed in a vehicle and can be displaced from a normal position to an emergency position when a rear-end collision occurs, and is installed in various types of vehicles. It can be suitably applied to a seat back of a sheet.

It is the sectional side view which showed the state which the attitude | position of the headrest of the Example displaced to the emergency position. It is the sectional side view which showed the state by which the headrest of the Example was hold | maintained at the normal position. (a) is the principal part sectional side view which showed the position of the lock plate in case the headrest main body has faced the normal position, (b) is a head plate main body moving to an emergency position, and a lock plate is 2nd. It is the principal part sectional side view which showed the state latched by the latching recessed part. (a) is principal part sectional drawing which looked at the state of Fig.3 (a) from the front, (b) is principal part sectional drawing which looked at the state of FIG.3 (b) from the front. It is the perspective view which showed each structural member of the headrest support body which comprises a headrest, a rotation support mechanism, a holding mechanism, a cancellation | release mechanism, and a return mechanism. It is the perspective view which showed the state which attaches a headrest core to a headrest support body. It is the perspective view which showed the bracket attached to the outer bottom face of a headrest main body, the lock plate arrange | positioned at this bracket, and a compression coil spring. (a) is a perspective view showing a state in which a holding mechanism, a release mechanism, and a return mechanism are assembled, and (b) is a perspective view showing a hook member, a connecting arm member, and a balancer disposed on a mounting bracket. is there. It is the disassembled perspective view which showed the hook member, the connection arm member, the balancer, the inertia weight, the support arm, etc. (a) is explanatory drawing which showed the balance state of the balancer, (b) is explanatory drawing which showed that the inertia weight accommodated in the balancer slides back. (a) is sectional drawing which showed the state by which a rotation support member is hold | maintained in a 1st position by a hook member, (b) shows the state to which an inertia weight moves relatively back at the time of a vehicle rear-end collision. FIG. (a) is a cross-sectional view showing a state in which the connection arm member is pulled rearward by the movement of the inertia weight to the rear of the vehicle, and the engagement between the lock pin and the locking portion is released, (b) It is sectional drawing which showed that a hook member rotated to a cancellation | release state, and a rotation support member displaced to a 2nd position. (a) is a sectional view showing a state in which the moving shaft abuts on the engaging recess of the hook member when the headrest body is returned to the normal position, and (b) is a state where the headrest body is further pushed from the normal position. FIG. 5 is a cross-sectional view showing a state in which the lock pin and the engaging portion are engaged. It is sectional drawing which showed the state by which the latching | locking part was engaged with the lock pin by releasing the pushing with respect to a headrest main body, and the rotation support member was hold | maintained in the 1st position. It is a sectional side view which shows the relationship between the stopper hole and weight shaft which were formed in the attachment bracket. (a) is an explanatory view showing the relationship between the stopper hole and the guide hole when the seatback inclination angle R = the rearward inclination limit angle R2 shown in FIG. 18, and (b) is shown in FIG. FIG. 6 is an explanatory diagram showing a relationship between a stopper hole and a guide hole when the seat back inclination angle R> the rear inclination limit angle R2. (a) is an explanatory view showing the relationship between the stopper hole and the guide hole when the seatback inclination angle R = the forward inclination limit angle R1 shown in FIG. 18, and (b) is shown in FIG. FIG. 6 is an explanatory diagram showing the relationship between the stopper hole and the guide hole when the seat back inclination angle R <the forward inclination limit angle R1. It is explanatory drawing which showed the operating range and non-operating range of the headrest of an Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Headrest support body (support body), 12 Headrest main body 36 Moving shaft (1st connection part), 40 Rotation support member (Attitude displacement means)
80 hook member (holding member), 81 lock pin (lock member), 84 engaging recess (second connecting portion)
85B Locking part, 96 Inertial weight (inertial member), 100 Support arm (support member)
110 Balancer (balance member), 119 Guide hole (guide part)
121 Movement restriction part, S1 seat back

Claims (5)

In a headrest comprising: a support body supported by a seat back of a vehicle seat; and a headrest body connected to the support body through posture displacement means and moving from a normal position to an emergency position at the time of a vehicle collision,
An inertia member disposed on the support and moving relative to the support relative to the support at the time of a vehicle collision;
A holding member that is disposed on the support and normally holds the headrest body in the normal position;
The holding member and the inertia member are linked to each other at a normal position of the headrest body with a clearance that allows the inertia member to move rearward of the vehicle independently of the holding member. A headrest, wherein a holding member is interlocked with an inertia member that moves beyond an amount, and movement of the headrest body to an emergency position is allowed. A balance member that has a guide portion that movably holds the inertia member, and is provided on the support so as to be swingable so that the guide portion extending in the front-rear direction is always in a horizontal state;
Located on the rear side of the movement path along the guide portion of the inertia member provided on the support body, the movement of the inertia member to the rear of the vehicle is within the range of the clearance by the amount of angular displacement of the support body in the longitudinal direction of the vehicle. The headrest according to claim 1, further comprising a movement restriction portion that restricts the movement of the headrest.   The headrest according to claim 1, further comprising a support member disposed on the support body and biasing the inertia member toward the front of the vehicle. The holding member includes a second connecting portion connectable to a first connecting portion provided on the headrest body, and holds the headrest body in the normal position by connecting the second connecting portion to the first connecting portion. Displaceable between a state and a release state in which the connection between the second connection part and the first connection part is released and the headrest body is allowed to move to the emergency position;
When the headrest body that has moved to the emergency position is returned to the normal position, the first connecting portion comes into contact with the second connecting portion of the holding member that is in the released state, and the holding member holds the holding member. The headrest as described in any one of Claims 1-3 comprised so that the said inertia member may be located in the position before a movement while displacing to a state. A locking portion provided on the holding member;
A locking member that engages with the locking portion in the holding state of the holding member and that is disengaged from the locking portion when the inertia member relatively moves rearward of the vehicle. The headrest as described in any one of 4.

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