JP2007330515A - Headrest for vehicle seat - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To make a structure for holding the posture position of the bearing part of an active headrest compact with respect to the front and back width of the headrest. <P>SOLUTION: The headrest 3 can move the bearing part 3a with respect to a stay 3b in collision of the vehicle. Regarding a four-bar linkage mechanism 10, the bearing part 3a is moved forward and upward from an initial position of a normal time with turning of a driving linkage 13 and a following linkage 14 in an advancing direction (clockwise). At the driving linkage 13, a pull-in groove 13b which can engage with an engaging pin 31 of a holding member 30 is formed between both of the connection shafts 10a and 10b. The holding member 30 is pivotally supported at a position eccentric in a radial direction from a connection shaft 10d with respect to a fixed linkage 12. The holding member 30 is normally made to be in an engaging state of entering the inside of the pull-in groove 13b by biasing of a tension spring Sa applied to the four-bar linkage mechanism 10, and regulates the turning of the four-bar linkage mechanism 10. In collision of the vehicle, the holding member 30 is pushed out from the pull-in groove 13b into a long hole 13a, and the engaging state is disengaged. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a headrest for a vehicle seat. More specifically, the present invention relates to a headrest for a vehicle seat provided with a moving means capable of moving a support portion for receiving a head of an occupant seated on a seat relative to a headrest base at the time of a vehicle collision.

2. Description of the Related Art Conventionally, some seats for automobile seats employ an active headrest that can support a passenger's head by instantaneously moving the headrest forward when a rear-end collision of the vehicle occurs. For example, the following Patent Document 1 discloses a technique for moving a support portion serving as a head receiving portion of a headrest forward using the movement of a four-bar linkage mechanism. In this disclosure, a four-bar linkage mechanism is provided between a headrest base portion and a support portion that are assembled and fixed to a seat back. A spring member is set between the fixed link fixed to the headrest base side of the four-bar linkage mechanism and another movable link. As a result, the four-link mechanism is normally biased in the rotational direction that moves the support portion forward. Here, the four-joint link mechanism is always held in a posture state at an initial position in which the support portion is retracted to the headrest base side before the vehicle collision occurs. When the vehicle collision occurs, this holding state is released, and the support portion is urged and moved forward.
Further, the four-bar linkage mechanism is held in the posture state by the stopper structure or the latch engagement structure in the posture state in which the support portion is moved forward. Specifically, in the four-link mechanism, the movable link is brought into contact with the stopper by moving the support portion forward, and the movement in the traveling direction is restricted. Furthermore, with this restriction, a latch structure provided integrally with the movable link is engaged with an engagement member provided on the headrest base side. Thereby, the movement to the backward direction of a support part is controlled. Therefore, in the posture state in which the support portion is moved forward, even if the head tilts backward due to the momentum of the collision, the support portion can be received at that position without being pushed back. Thereby, the excessive backward inclination of a head can be prevented and the load concerning a neck part can be reduced.
JP 2002-142910 A

  However, in the above-described conventional disclosed technology, the structure portion for holding the posture position of the support portion with respect to the headrest base portion is provided so as to project to the rear side of the four-bar linkage mechanism. Therefore, the front and rear width of the headrest is necessary.

  The present invention has been devised as a solution to the above-described problem, and the problem to be solved by the present invention is to provide a structure for maintaining the posture position of the support portion with respect to the headrest base portion, and the front-rear width of the headrest. It is to make it compact.

In order to solve the above problems, the headrest of the vehicle seat of the present invention takes the following means.
A first aspect of the present invention is a vehicle seat headrest provided with moving means capable of moving a support portion for receiving a head of an occupant seated on a seat relative to a headrest base portion at the time of a vehicle collision. The moving means includes a four-bar linkage mechanism provided between the support section and the headrest base section, and a drive for rotating the four-bar link mechanism in one direction at the time of a vehicle collision to move the support section toward the collision corresponding position. And a device. In the four-bar linkage mechanism, a movable link fixed to the support part side and a fixed link fixed to the headrest base side are connected by a driving link and a driven link so that they can move relative to each other, and when the driving link and the driven link collide with each other. With the rotation in one direction, the position of the support portion moves relatively forward and upward from the normal initial position with respect to the headrest base portion. The driving device includes a biasing member that biases the four-bar linkage mechanism in one direction, and a holder that holds the four-bar link mechanism so that the support portion is held at an initial position against the biasing of the biasing member. And a member. The driving link or the driven link of the four-bar link mechanism is provided with an engaging portion that can engage with the holding member at a position between the connecting shaft for the movable link and the connecting shaft for the fixed link. The holding member is pivotally supported by a fixed link or a member integral therewith, and the pivot is separated from a connecting shaft that connects one link provided with an engaging portion and the fixed link. Normally, the holding member is brought into a locked state where it is abutted against the engaging portion by the urging force of the urging member applied to the four-bar linkage mechanism, and is rotated in one direction. When the vehicle collides, the holding member is released from the locked state with the engaging portion by the release operation mechanism that releases the held state of the four-bar linkage mechanism.
According to the first aspect of the invention, the four-bar link mechanism is urged in one rotation direction by the urging member. However, the holding member is usually provided in the engaging portion provided in the driving link or the driven link. As a state of being abutted and locked, rotation in the biased direction is restricted. Thereby, the support part is hold | maintained in the initial position of normal time. The engaging portion is disposed at a position between the connecting shaft for the movable link of the one link and the connecting shaft for the fixed link. The holding member is pivotally supported so as to be rotatable at a position apart from the connecting shaft between the one link and the fixed link, and is locked to the engaging portion by abutment. The holding member is released from the locked state with the engaging portion by being swung by the release operation mechanism at the time of a vehicle collision. As a result, the four-bar linkage mechanism rotates in one direction in accordance with the urging force of the urging member. And thereby, a support part moves to the front and upper direction relatively with respect to a headrest base, and moves to a collision corresponding position.

Further, according to a second aspect of the present invention, in the first aspect described above, the engaging structure of the one link provided with the engaging portion of the four-bar linkage mechanism and the holding member is an engaging pin provided on the holding member. Is slidably fitted into a long hole formed along the longitudinal direction of one of the links, and refracted perpendicularly to the longitudinal direction at one end of the long hole, and the engaging pin is drawn from the long hole. A retractable groove is formed as the engaging portion. In the state where the engaging pin is pulled into the slot of the elongated hole, the holding member is restricted from sliding in the longitudinal direction in the slot and is rotated in one direction of the one link where the slot is formed. To regulate.
According to the second aspect of the invention, the holding member has a turning locus different from that of the one link on which the engaging portion is formed. Accordingly, the holding member rotates while sliding the engagement pin within the long hole as the one link rotates. Therefore, the holding member is in a state where the sliding movement of the engaging pin in the longitudinal direction is restricted in a state where the engaging pin is drawn into the drawing groove, and the holding member restricts the rotation of the link in one direction. It becomes a state. Then, the holding member is allowed to slide in the longitudinal direction of the engaging pin when the engaging pin is pulled out of the pulling groove by the release operation mechanism at the time of the collision of the vehicle. Thereby, the rotation of the link in one direction is allowed.

Next, according to a third aspect of the present invention, in the second aspect described above, the other end of the elongated hole formed in the driving link or the driven link is configured such that the four-bar linkage mechanism rotates in one direction and the support portion corresponds to the collision. When the position is reached, the stopper comes into contact with an engagement pin provided on the holding member to lock the slide movement.
According to the third aspect of the present invention, when the four-bar linkage mechanism rotates in one direction, the holding member rotates while sliding the engagement pin within the long hole formed in one of the links. The engaging pin comes into contact with the other end of the long hole and locks when the support portion reaches the collision-corresponding position. Thereby, a holding member will be in the latching state which controlled rotation to the one direction of one link.

The present invention can obtain the following effects by taking the above-described means.
First, according to the first aspect of the present invention, an engaging portion is provided at a position between both connecting shafts of the driving link or the driven link constituting the four-bar linkage mechanism, and the holding member is locked by abutting against the engaging portion. By providing the structure, the structure for maintaining the posture position of the support portion can be stored compactly with respect to the front-rear width of the headrest.
Further, according to the second invention, the engagement pin of the holding member is engaged with and disengaged from the drawing groove formed in the long hole, so that the holding at the initial position of the four-bar linkage mechanism is more stable. Can be done. Further, since the movement of the holding member can be restricted within the range of the shape of the long hole or the drawing groove into which the engagement pin is fitted, it is possible to prevent malfunction during the operation.
Furthermore, according to the third aspect, the four-link mechanism can be restricted from rotating in one direction when the support portion reaches the collision corresponding position by using the length shape of the long hole. In other words, depending on the shape of the long hole, the four-link mechanism can be held at the initial position and held at the collision corresponding position.

  Embodiments of the best mode for carrying out the present invention will be described below with reference to the drawings.

First, the headrest of the vehicle seat according to the first embodiment will be described with reference to FIGS. FIG. 1 is a configuration diagram showing a schematic configuration of the headrest 3 in a side view. FIG. 2 is a perspective view of the skeleton structure of the headrest 3 and the seat back 2 as seen from the back side. FIG. 3 is a perspective view showing an initial posture state of the four-bar linkage mechanism 10. FIG. 4 is a perspective view showing the posture state after the rotation of the four-bar linkage mechanism 10. FIG. 5 is a configuration diagram illustrating the movement of the four-bar linkage mechanism 10 before and after rotation in a side view. FIG. 6 is a perspective view of the movement of the pressure plate 21 before and after movement as seen from the front side. FIG. 7 is a side view of FIG. FIG. 8 is an enlarged configuration diagram of the driving link 13.
Here, in FIGS. 2 to 7, the skin structure of the headrest 3 and the seat back 2 is omitted, and only the internal framework structure is shown for easy understanding of the configuration of the present embodiment. Therefore, in the following description, when describing the skin structure of the headrest 3 and the seat back 2, FIG.

  As shown in FIG. 1, the headrest 3 of the present embodiment constitutes a part of the vehicle seat 1 and supports the head of an occupant seated on the seat 1 from the rear side. . The headrest 3 is installed on the upper portion of the seat back 2 and is always maintained in the installed posture state. However, the headrest 3 is configured to instantaneously move the curved plate-shaped support portion 3a that receives the head of the occupant when a rear-end collision of the vehicle occurs. As a result, when the rear collision of the vehicle occurs, only the support portion 3a is moved close to the back of the back of the head alone with respect to an occupant in a sitting posture with the body floating forward from the seat back 2 or the headrest 3. Can do. Therefore, when a rear collision occurs, the head can be supported so as not to tilt backward due to the momentum, and the load on the neck can be reduced.

Here, the above-described forward movement of the support portion 3 a is performed along with the rotation of the four-bar linkage mechanism 10 incorporated in the headrest 3. The four-joint link mechanism 10 is provided between the support portion 3 a and the stay 3 b that is a support column of the headrest 3. The four-joint link mechanism 10 is normally held in the posture state shown by the solid line in FIG. 5 and holds the curved plate-shaped support portion 3a (see FIG. 1) in the initial position. . The four-joint link mechanism 10 is rotated in the direction in which the support portion 3a is moved forward by the urging force (the advancing direction indicated by the arrow) when the holding state is released by the occurrence of a rear-end collision of the vehicle. Move. As a result, the four-joint link mechanism 10 moves the support portion 3a relatively forward and upward from the normal initial position (solid line state) with respect to the stay 3b, as indicated by the phantom line in FIG. . Here, the urging | biasing rotation to the advancing direction of the 4-joint link mechanism 10 is controlled by the state position shown with the virtual line. And thereby, the support part 3a can be hold | maintained as the state moved close to the collision corresponding position just behind the head. Here, the initial posture state of the four-bar linkage 10 is shown in a perspective view in FIG. 3, and the posture state after the rotation is shown in a perspective view in FIG.
By the way, the operation of releasing the holding state of the four-bar linkage mechanism 10 described above is performed by the operation of the release operation mechanism 20 shown in FIG. The release operation mechanism 20 is disposed inside the seat back 2. The release operation mechanism 20 is connected to a push cam 40 that performs a release operation of the holding member 30 that holds the four-bar linkage mechanism 10 in an initial position by engagement. Here, the release operation mechanism 20 is configured to be pushed backward by receiving a backrest load that causes the back of the occupant to largely press against the seat back 2 due to the occurrence of a rear collision of the vehicle. . Then, the release operation mechanism 20 operates the push cam 40 by this push to release the locked state between the holding member 30 and the four-bar linkage mechanism 10.
Hereinafter, each configuration of the four-bar linkage mechanism 10 and the release operation mechanism 20 will be described in detail.

First, the four-bar linkage mechanism 10 will be described.
That is, the four-bar link mechanism 10 includes a movable link 11, a fixed link 12, a driving link 13, and a driven link 14, as shown in FIG. Each of these links is formed of resin.
Specifically, the movable link 11 is configured as the curved plate-shaped support portion 3a described above. The fixed link 12 is formed in a thick plate shape, and is integrally connected to the stays 3 b and 3 b of the headrest 3. Here, the fixed link 12 corresponds to the headrest base of the present invention. The driving links 13 and 13 and the driven links 14 and 14 are linked to and connected to the movable link 11 and the fixed link 12. The driving links 13 and 13 and the driven links 14 and 14 have a pair of left and right configurations in the width direction of the headrest 3. The driving links 13 and 13 and the driven links 14 and 14 are linked to the movable link 11 and the fixed link 12 by long bar-shaped connecting shafts 10a to 10d, respectively, and the left and right movements are performed in synchronization. It has come to be.
Further, a tension spring Sa is stretched between the connecting shaft 10a and the connecting shaft 10c of the four-bar linkage mechanism 10. Here, the tension spring Sa corresponds to the biasing member of the present invention. By this tension spring Sa, the four-bar linkage mechanism 10 is normally urged in the turning direction of the advancement. Here, the turning direction of the four-joint link mechanism 10 is the direction in which the driving links 13 and 13 turn clockwise about the connecting shaft 10d as seen in FIG.

Further, in the driving link 13 arranged on the side shown in FIG. 5 (left side in the width direction of the headrest 3), a long hole 13a is formed along the longitudinal direction of the link. An engagement pin 31 provided on the holding member 30 is slidably fitted in the long hole 13a. The configuration of the driving link 13 is illustrated in detail in FIG.
Here, the holding member 30 is formed in a link shape with resin. One end of the holding member 30 is pivotally supported on the fixed link 12 by a connecting shaft 30a parallel to the connecting shafts 10a to 10d. Specifically, the connecting shaft 30a is disposed at a position spaced forward and upward from the connecting shaft 10d. An engaging pin 31 protruding in the axial direction is provided at the other end of the holding member 30. As described above, the engaging pin 31 is fitted in the elongated hole 13a of the driving link 13 so as to be slidable in the longitudinal direction (see FIG. 8). Accordingly, when the four-bar linkage mechanism 10 rotates in the traveling direction (clockwise direction), the holding member 30 itself moves in the traveling direction while sliding the engagement pin 31 in the longitudinal direction in the long hole 13a. It is designed to rotate.
By the way, as shown in FIG. 8, the above-described long hole 13a has a pull-in shape that is refracted in a direction perpendicular to the longitudinal direction at the end (one end) on the side supported by the connecting shaft 10d. A groove 13b is formed. As shown by the solid line in the figure, the pull-in groove 13b is formed so that the engaging pin 31 can be pulled into the interior when the driving link 13 is in the initial position. As shown in FIG. 5, when the engagement pin 31 is retracted into the retracting groove 13b, the four-link mechanism 10 is urged to rotate in the traveling direction by the tension spring Sa. The holding member 30 is brought into contact with the driving link 13 by 31.
That is, the holding member 30 is pivotally supported at a position (connection shaft 30 a) that is radially separated from the shaft support position (connection shaft 10 d) of the driving link 13, and has a rotation locus different from that of the driving link 13. ing. Therefore, if the holding member 30 is in a state where the engaging pin 31 is not drawn into the drawing groove 13b (a state where the holding pin 30 is in the long hole 13a), the holding member 30 extends the engaging pin 31 as the driving link 13 rotates. It rotates together while sliding in the hole 13a. However, the holding member 30 is in a state in which the sliding movement of the engagement pin 31 in the longitudinal direction is restricted when the engagement pin 31 is pulled into the pull-in groove 13b. Accordingly, the holding member 30 is brought into a locked state in which the rotation is restricted by being abutted against the driving link 13 that is about to rotate in the traveling direction.
Further, as shown in FIG. 8, the end 13c of the long hole 13a, that is, the end opposite to the above-described rotation center can be locked by the sliding movement of the engagement pin 31 by contact. ing. Here, the end 13c of the long hole 13a corresponds to the other end of the present invention. As shown by the phantom line in FIG. 5, the terminal end 13c of the long hole 13a is an engagement pin when the support portion 3a reaches the collision corresponding position by the rotation of the four-bar linkage mechanism 10 in the traveling direction. 31 comes into contact. As a result, the sliding movement of the engaging pin 31 in the longitudinal direction is restricted, and the holding member 30 is abutted against the driving link 13 that is about to turn in the traveling direction, and the locking is restricted. It becomes a state.

Next, the configuration of the push cam 40 will be described. That is, as shown in FIG. 4, the push cam 40 is disposed on the left side in the width direction of the fixed link 12, and is pivotally supported on the fixed link 12 by the connecting shaft 10d described above. Yes.
The push cam 40 is formed of resin, and is formed in a substantially triangular shape with the connecting portion with the connecting shaft 10d as the apex as well shown in FIG. A curved guide hole 41 is formed in the push cam 40. The guide hole 41 is formed in a shape that is smoothly curved in the lower right direction in the drawing of the push cam 40 shown by a solid line in FIG. And the upper end of the inner cable of the cable member 24 mentioned later is hooked in this guide hole 41 so that the inside of the guide hole 41 is slidably movable.
As a result, when the inner cable is pulled down in the drawing, the rotating cam is pushed clockwise in such a manner that the inner peripheral surface of the guide hole 41 is pressed by the inner cable. Yes. And by this clockwise rotation, the pushing cam 40 pushes the holding member 30 drawn into the inside of the aforementioned drawing groove 13b from the lower side and pushes it out from the drawing groove 13b (see FIG. 8). . As a result, the engagement pin 31 is allowed to slide in the longitudinal direction within the long hole 13a. That is, the driving link 13 (four-bar linkage mechanism 10) is allowed to rotate in the traveling direction.

Here, as shown in FIG. 1, the rotation of the four-bar linkage mechanism 10 in the traveling direction (arrow direction) is restricted by the contact between the terminal end 13 c of the long hole 13 a and the engagement pin 31 of the holding member 30. In the state where the support portion 3a is moved to the position corresponding to the collision, the posture state of the four-bar link mechanism 10 is as follows. That is, the driving link 13 and the driven link 14 are in a posture state in which the linking shaft 10d or the linking shaft 10a with respect to each fixed link 12 faces upward from the horizontal. As a result, the movable link 11 configured as the support portion 3a is configured to apply the receiving load for receiving the head of the occupant to the four-link mechanism 10 between the end 13c of the long hole 13a and the engagement pin 31 of the holding member 30. It is in a posture state in which it acts as a pressing force for rotating in the traveling direction regulated by the contact.
Therefore, when a rear-end collision of the vehicle occurs, even if a receiving load that catches the head of the occupant leaning backward acts on the support portion 3a, the support portion 3a is in a direction opposite to the traveling direction (the direction opposite to the arrow). It is held in a state where it is not pushed back.

Next, the release operation mechanism 20 will be described.
That is, as shown in FIG. 6, the release operation mechanism 20 includes a pressure plate 21, a shaft support member 22, an arm member 23, and a cable member 24. Each of these members is disposed inside the shape of the seat back 2. Specifically, as shown in FIG. 7, each member is disposed so as to fit in the front-rear width of the side frame Fs of the back frame 2 f that forms the skeleton of the seat back 2. Note that the lower end side of the cable member 24 is disposed inside the seat back 2, but the upper end side is a stay provided on the left side in the width direction of the headrest 3, as shown in FIG. By being inserted through the inside of 3b, it is arranged inside the shape of the headrest 3.
Specifically, as shown in FIG. 6, the pressure plate 21 is formed in a curved shape in which the upper and lower edges of the pressure plate 21 are warped toward the rear side of the seat back 2. The pressure plate 21 is fixed integrally with a shaft support member 22 that is pivotally connected to the side frame Fs at a lower rear position. Specifically, the shaft support member 22 is connected to a reinforcing member Rf that is spanned between the side frames Fs and Fs and fixed thereto by a shaft support bracket Rb that is further fixed to the reinforcing member Rf. Has been. As a result, the pressure plate 21 can be pushed and pulled in the front-rear direction within the shape of the seat back 2. The pressure plate 21 is normally held at the front position shown by the solid line in FIGS. 6 and 7. Then, when the rear collision of the vehicle occurs, the back of the occupant receives a backrest load that tends to largely press against the seatback 2 and is pushed backward as indicated by the phantom line in FIG. .

Next, as shown in FIG. 7, the arm member 23 is fixed integrally with the shaft support member 22, and rotates together with the pressure plate 21 and the shaft support member 22. Specifically, the arm member 23 is formed in a shape that extends the arm toward the front of the shaft support member 22. Thereby, the whole shape which consists of the integral structure of the pressurizing plate 21, the shaft support member 22, and the arm member 23 is formed in the L-shaped frame shape centering on the shaft support member 22 which is a bending point. The lower end of the outer cable 24b of the cable member 24 is integrally fixed to the arm member 23.
Here, the cable member 24 has a configuration in which an inner cable 24a having flexibility is inserted into a tubular outer cable 24b having flexibility but relatively high rigidity. The lower end of the outer cable 24b is fixed to the arm member 23 as described above, and the lower end of the inner cable 24a is fixed integrally with the back frame 2f as shown in FIG. Further, as shown in FIG. 3, the upper end of the outer cable 24b is fixed integrally with the stay 3b of the headrest 3, and the upper end of the inner cable 24a is inserted into the guide hole 41 of the push cam 40 as described above. It is laid. The upper end of the inner cable 24a is formed by a relatively rigid wire member, and the push cam 40 can be pushed and moved in accordance with the pulling operation.

  Therefore, returning to FIG. 7, the cable member 24 is pulled by an operation in which the pressure plate 21 is pushed rearward. That is, when the pressure plate 21 is pushed rearward, the arm member 23 lifts the lower end of the outer cable 24b upward. As a result, the lower end side of the inner cable 24a inserted inside is relatively pulled out, and the length of the inner cable 24a on the upper end side with respect to the outer cable 24b is shortened. That is, the inner cable 24a on the upper end side is pulled. Then, as shown in FIG. 5, when the upper end side inner cable 24a is pulled, the pushing cam 40 is pushed in the clockwise direction in the drawing. As a result, as shown in FIG. 8, the engaging pin 31 is pushed out from the drawing groove 13 b, and the locked state between the holding member 30 and the driving link 13 is released. In addition, the pushing cam 40 is returned to the posture state before being automatically pushed and moved by the action of gravity when the pulling state by the inner cable 24a is released. Therefore, by performing an operation of returning the four-bar linkage mechanism 10 rotated in the traveling direction to the initial position, the engaging pin 31 automatically enters the drawing groove 13b by the action of gravity, and the holding member 30 and the driving force are moved. The link 13 is again locked.

Next, the usage method of a present Example is demonstrated.
That is, as indicated by the phantom line in FIG. 1, in the normal initial state of the headrest 3, the support portion 3a is held in the initial position. Then, referring to FIG. 6, when a rear collision of the vehicle occurs, the occupant's back is greatly pressed against the seat back 2 with the momentum, and the pressure plate 21 is pushed rearward. Thereby, as shown in FIG. 5, the cable member 24 is pulled, and the holding state of the four-bar link mechanism 10 by the holding member 30 is released. As a result, the four-joint link mechanism 10 is rotated in the advancing direction (arrow direction) to the position where the engaging pin 31 of the holding member 30 contacts the terminal end 13c of the long hole 13a by the biasing force of the tension spring Sa. . As a result, as shown by the phantom line in the figure, the support portion 3a is moved from the initial position (solid line state) forward and upward to the collision corresponding position, and the head tilts backward at the same position. It will be ready to come. Returning to FIG. 1, since the support portion 3 a has moved to the collision-corresponding position (solid line position), the receiving load accompanying the backward tilting of the head applied to the support portion 3 a causes the four-bar link mechanism 10 to travel in the traveling direction. It acts as a pressing force for rotating the engaging pin 31, that is, a pressing force for sliding the engaging pin 31 in the longitudinal direction regulated by the terminal end 13 c of the long hole 13 a. Therefore, the support portion 3a is not pushed back in the direction opposite to the traveling direction even when receiving the above-described receiving load, and receives the occupant's head at the collision corresponding position.
In order to return the support portion 3a moved to the collision-corresponding position (solid line position) to the original initial position (virtual line position), the four-bar linkage mechanism 10 moves against the bias of the tension spring Sa. What is necessary is just to operate so that it may return in the rotation direction opposite to a direction (arrow direction). As a result, as shown in FIG. 5, the engaging pin 31 automatically falls into the drawing groove 13b, so that the support portion 3a can be held in the initial position again.

Thus, in the headrest of the vehicle seat of the present embodiment, the long hole 13a and the drawing groove 13b are provided between the connecting shaft 10c and the connecting shaft 10d of the driving link 13 constituting the four-bar linkage mechanism 10, The engaging pin 31 of the holding member 30 is abutted and locked in the drawing groove 13b. Thereby, the structure for maintaining the posture position of the support portion 3 a can be stored compactly with respect to the front-rear width of the headrest 3.
Furthermore, since the movement of the holding member 30 can be restricted within the range of the shape of the long hole 13a and the pulling groove 13b in which the engagement pin 31 is fitted, it is possible to prevent malfunction during the operation. Further, by using the length shape of the long hole 13a, it is possible to regulate the rotation of the four-bar linkage mechanism 10 in the traveling direction when the support portion 3a reaches the collision corresponding position. That is, the shape of the long hole 13a makes it possible to hold the four-bar linkage mechanism 10 at the initial position and hold it at the collision handling position.

Next, the headrest of the vehicle seat according to the second embodiment will be described with reference to FIGS. FIG. 9 is a configuration diagram illustrating a schematic configuration of the headrest 3 in a side view. FIG. 10 is a configuration diagram showing the driving link 13 in an enlarged manner.
In the present embodiment, the parts having substantially the same configuration and operation as those of the members shown in the first embodiment are denoted by the same reference numerals, the description thereof will be simplified, and the different parts will be described in detail. .

In the present embodiment, as shown in FIG. 10, a drop portion 13 d having a step shape is formed on the upper surface portion of the driving link 13. Here, the drop portion 13d corresponds to the engaging portion of the present invention. As shown by the solid line in the figure, the drop portion 13d is formed so that the engagement pin 31 can drop into the interior when the driving link 13 is in the initial position. As shown in FIG. 9, in a state where the engagement pin 31 has fallen into the drop portion 13 d, the four-link mechanism 10 is urged to rotate in the traveling direction by the tension spring Sa, whereby the engagement pin 31. Thus, the holding member 30 is brought into contact with the driving link 13.
The holding member 30 is released from the locked state due to abutment with the driving link 13 when the engaging pin 31 is pressed by the pressing cam 40 and pushed out from the drop portion 13d. Accordingly, the holding member 30 rotates while sliding the engagement pin 31 along the upper surface of the driving link 13 as the four-bar linkage mechanism 10 rotates in the traveling direction (see FIG. 10). As shown in FIG. 9, the four-joint link mechanism 10 includes a stopper portion 12 s in which the upper surface portion of the driven link 14 is integrally formed with the fixed link 12 when the support portion 3 a reaches the collision corresponding position. It abuts and its rotation in the direction of travel is regulated.
Thus, in the headrest of the vehicle seat of the present embodiment, a structure that holds the four-bar link mechanism 10 in the initial state posture state by forming the drop portion 13d that falls in a step shape on the upper surface portion of the driving link 13. Can be embodied as a relatively simple configuration.

Although the embodiment of the present invention has been described with respect to one example, the present invention can be implemented in various forms in addition to the above-described example.
For example, the four-link mechanism may be configured to be directly rotated in the traveling direction by a cable member that is pulled by a pressure plate. A configuration in which such a cable member directly rotates the four-bar link mechanism is disclosed in documents such as JP-A-2005-104259.
In addition, the four-bar link mechanism is shown in a posture state in which the driving link and the driven link both face upward from the horizontal in the posture state of the collision corresponding position. However, the posture state of the four-bar link mechanism only needs to be a posture state in which the receiving load that receives the occupant's head by the support portion acts as a pressing force that further rotates the four-bar link mechanism in the traveling direction. It is not particularly limited.
Moreover, although the structure in which the holding member is pushed out by the push cam is shown, the cable member may be directly hooked on the holding member and pushed and pulled.
In addition, the engaging pin provided in the holding member enters the pulling groove (Example 1) and the drop-in part (Example 2) of the driving link, so that the holding member is brought into contact with the driving link and locked. I showed that. However, for example, if the configuration is such that the engaging pin is abutted perpendicularly to the driving link, the engaging portion can be realized without forming the step shape as described above.
Moreover, although the elongate hole, the drawing groove | channel (Example 1), and the drop part (Example 2) which were formed in the drive link showed what was directly formed in the drive link itself, it was comprised integrally with this. It may be formed on the member. Moreover, the engaging part may be formed in the driven link. Further, the engaging portion may be formed on the movable link, but in this case, an urging member for bringing the holding member against the movable link against the action of gravity may be separately required. .
Further, the engaging pin of the holding member may be dropped into the drawing groove (Example 1) or the drop-in part (Example 2) by the urging force of the urging member such as a spring.

It is the block diagram which represented schematic structure of the headrest of Example 1 by the side view. It is the perspective view which looked at the frame structure of a headrest and a seat back from the back side. It is a perspective view showing the initial posture state of the four-bar linkage mechanism. It is a perspective view showing the posture state after rotation of a 4-joint link mechanism. It is the block diagram which represented the motion before and behind rotation of a 4 node link mechanism by the side view. It is the perspective view which looked at the movement before and behind the movement of a pressurization board from the front side. FIG. 7 is a side view of FIG. 6. It is the block diagram which expanded and expressed the drive link. FIG. 5 is a configuration diagram illustrating a schematic configuration of a headrest according to a second embodiment. It is the block diagram which expanded and expressed the drive link.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Seat 2 Seat back 2f Back frame 2s Support 3 Headrest 3a Supporting part 3b Stay 10 Four-bar link mechanism 10a-10d Connecting shaft 11 Movable link 12 Fixed link (headrest base)
12s Stopper 13 Drive link 13a Long hole 13b Pull-in groove 13c Termination (other end)
13d Drop part (engagement part)
DESCRIPTION OF SYMBOLS 14 Follower link 20 Release operation mechanism 21 Pressure plate 22 Shaft support member 23 Arm member 24 Operation cable 24a Inner cable 24b Outer cable 30 Holding member 30a Connection shaft 31 Engagement pin 40 Push cam 41 Guide hole Sa Tension spring (Biasing member) )
Fs Side frame Fu Upper frame Rf Reinforcement member Rb Shaft support bracket

Claims (3)

A vehicle seat headrest provided with moving means capable of moving a support portion for receiving a head of an occupant seated on a seat relative to a headrest base at the time of a vehicle collision,
The moving means is
A four-bar linkage mechanism provided between the bearing and the headrest base;
A drive device for rotating the four-bar linkage mechanism in one direction at the time of a vehicle collision and moving the support portion toward a collision-responsive position;
In the four-joint link mechanism, a movable link fixed to the support portion side and a fixed link fixed to the headrest base portion side are connected to each other by a driving link and a driven link so as to be capable of relative movement. The structure is such that the position of the support portion moves relatively forward and upward from the normal initial position with respect to the headrest base as the link is pivoted in one direction at the time of collision.
The driving device includes:
An urging member that urges the four-bar linkage mechanism to rotate in one direction;
A holding member that holds the four-bar linkage so that the support portion is held in an initial position against the biasing of the biasing member;
The driving link or the driven link of the four-bar linkage mechanism is provided with an engaging portion that can be engaged with the holding member at a position between a connecting shaft for the movable link and a connecting shaft for the fixed link.
The holding member is pivotally supported by the fixed link or a member integral with the fixed link, and the pivot supports the one link provided with the engaging portion and the fixed link. The holding member is normally held at a position abutted against the engagement portion by the urging force of the urging member applied to the four-node link mechanism. The link mechanism is restricted from rotating in one direction, and when the vehicle collides, the holding member is released from the locked state by the release operation mechanism that releases the held state of the four-bar link mechanism. A vehicle seat headrest. The vehicle seat headrest according to claim 1,
In the engagement structure between the one link provided with the engagement portion of the four-bar linkage mechanism and the holding member, an engagement pin provided on the holding member is formed along the longitudinal direction of the one link. A retraction groove that is slidably fitted into the long hole and that is refracted in a direction perpendicular to the longitudinal direction at one end of the long hole and can draw the engagement pin from the long hole is used as the engagement portion. Formed,
In the state in which the engagement pin is pulled into the pull-in groove of the long hole, the holding member is restricted to slide in the longitudinal direction in the long hole and is one of the links in which the pull-in groove is formed. A headrest for a vehicle seat, characterized by restricting rotation in a direction. The vehicle seat headrest according to claim 2,
The other end of the long hole formed in the driving link or the driven link is a member provided in the holding member when the four-bar linkage mechanism rotates in one direction and the support portion reaches the collision-corresponding position. A headrest for a vehicle seat, wherein the headrest serves as a stopper that comes into contact with a mating pin and locks its sliding movement.

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