JP4631802B2 - Headrest operating mechanism for vehicle seat - Google Patents

Description

  The present invention relates to a headrest operating mechanism for a vehicle seat. More specifically, the present invention relates to a headrest operating mechanism for a vehicle seat 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.

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 where the support portion is pulled into the headrest base side by the holding mechanism before the vehicle collision occurs. When a vehicle collision occurs, the holding state by the holding mechanism is released, and the support portion is urged and moved forward.
By the way, the operation of releasing the holding state of the above-mentioned four-bar linkage mechanism is performed in conjunction with the movement of the pressure plate disposed inside the seat back. The pressure plate is pivotally supported inside the seat back so as to be rotatable. As a result, when a rear-end collision of the vehicle occurs, the pressurizing plate is pushed and moved by receiving a backrest load that causes the back of the occupant to largely press the seat back. A cable member is stretched between the pressure plate and the holding mechanism of the four-bar linkage mechanism. Specifically, the cable member is hooked to an arm member formed integrally with the pressure plate. The arm member is formed in a shape in which the arm extends from the shaft portion serving as the rotation center of the pressure plate toward the rear side. Thereby, the cable member is pulled by the swing of the arm member in accordance with the movement of the pressure plate, and the release operation of the holding mechanism can be performed.
JP 2005-104259 A

  However, in the above-described conventional disclosed technique, it is necessary to provide a high support strength to the connection structure for pivotally supporting the pressure plate inside the seat back. That is, in the above disclosed technique, the pressure plate is hinged to the frame member that is installed between the back frames that form the skeleton of the seat back. Therefore, if the support strength of the frame member is weak, the frame member that has been subjected to the pressing force against the pressure plate is deflected and deformed when a rear collision of the vehicle occurs, and the movement of the center of rotation causes the pressure plate to move. The rotation cannot be performed efficiently. As a result, the cable member cannot be pulled stably.

  The present invention has been devised to solve the above-described problems, and the problem to be solved by the present invention is to pull a cable member for switching the operation state of an active headrest at the time of a vehicle collision. The purpose is to enable stable operation.

In order to solve the above-described problems, the vehicle seat headrest operating mechanism of the present invention takes the following means.
First, the first invention is a headrest operating mechanism for a vehicle seat 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. A rocking body disposed inside the seat back, a cable member that connects the rocking body and the moving means, and transmits the movement of the rocking body to the moving means as a push-pull motion. Is formed as a member extending in the vertical direction within the shape of the seat back, and is attached to the back frame forming the skeleton of the seat back, and the back of the occupant presses against the seat back in the event of a vehicle collision By receiving the backrest load, the rocking body is pushed and moved rearward, and the lower end portion thereof is displaced most greatly rearward. The inner cable having flexibility is inserted through the outer cable having flexibility, and the length of the inner cable with respect to the outer cable on one end can be changed to change the length of the other end. The inner cable is operated to push and pull, and the moving means is operated in accordance with the push and pull operation of the inner cable, so that the support part is moved from the initial position to the position corresponding to the collision. The other end side of the outer cable is fixed to the seat back integrally. The other end side of the inner cable is hooked to the moving means so that it can be pushed and pulled. The one end side of the inner cable is located at a position spaced downward from the lower end portion of the oscillating body. Characterized in that it is hooked to a fixed member provided integrally with the back frame Te.
According to the first aspect of the present invention, when a vehicle collision occurs, the occupant's back is greatly pressed against the seat back by the momentum. And by receiving this backrest load, a rocking body is pushed and moved to the back side. This rocking body extends in the vertical direction within the shape of the seat back. Therefore, the entire rocking body is pushed backward by receiving a backrest load at any part in the vertical direction. Specifically, the rocking body is pushed and moved to the rear side in such a manner that the lower end portion, which is the free end side, is displaced most greatly, instead of the portion that receives the backrest load being locally bent and deformed. Therefore, with the movement of the swinging body, one end side of the outer cable fixed to the lower end portion that is displaced most greatly moves relative to one end side of the inner cable fixed integrally with the back frame. As a result, the length of the inner cable with respect to the outer cable on one end side is changed, and the moving means fixed to the inner cable on the other end side is operated.
A fixing member for fixing one end side of the inner cable is provided integrally with the back frame. Therefore, one end side of the inner cable is held at a fixed position of the back frame with respect to one end side of the outer cable that moves largely rearward together with the swinging body.

Further, according to a second aspect of the present invention, in the first aspect described above, an operating shaft of a reclining mechanism that operates so that the backrest angle of the seat back can be changed is provided on both sides at the lower end portions of both side frames constituting the back frame. It is arranged in a state of being spanned between the frames. Further, between the side frames, interference between an assembly member such as a back pad assembled to the back frame and the operating shaft of the reclining mechanism is avoided. In addition, a reinforcing member having a supporting strength capable of reinforcing the supporting strength between the both side frames is fixed integrally with the both side frames, and is integrated with the back frame for hanging the lower end of the inner cable. The fixing member provided in is a reinforcing member.
According to the second invention, the reinforcing member protects the assembling member such as the back pad assembled to the back frame and the operating shaft of the reclining mechanism from interfering with each other, and supports between the side frames. It has support strength that can reinforce strength. Therefore, the one end side of the inner cable is suitably held by adopting the reinforcing member having the arrangement configuration and the supporting strength as described above as a fixing member in order to fix the one end side of the inner cable.

Next, according to a third aspect, in the first or second aspect, the initial state before the lower end portion of the oscillating body is pushed rearward between the lower end portion of the oscillating body and the back frame. An urging member that is held by urging is provided at the posture position, and the urging member applies an urging force that pushes the oscillating body upward as the oscillating body moves rearward. The swinging body is mounted such that the upper end portion thereof is movable in the vertical direction with respect to the back frame.
According to the third aspect, when the oscillating body is pushed rearward, it is pushed upward by the urging force of the urging member. Thereby, the one end side of the outer cable fixed to the lower end part of the rocking body relatively moves in a direction further separated from the one end side of the inner cable fixed to the lower side thereof.

The present invention can obtain the following effects by taking the above-described means.
First, according to the first invention, one end side of the outer cable is fixed to the lower end portion of the swinging body with respect to one end side of the inner cable fixed integrally with the back frame, and is largely displaced at the time of a vehicle collision. With the configuration, the cable member can be efficiently pulled. Therefore, the operation of switching the operating state of the active headrest at the time of a vehicle collision can be stably performed.
Furthermore, according to the second invention, since the reinforcing member is employed as a fixing member for fixing one end side of the inner cable, the one end side of the inner cable can be suitably held, and the structure can be rationalized. Can be achieved.
Furthermore, according to the third aspect of the present invention, the relative displacement of the outer cable with respect to the inner cable on one end side can be further increased by pushing the oscillating body to the upper side when moving backward. Therefore, the cable member can be pulled more efficiently.

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

First, a headrest operating mechanism for a vehicle seat according to the first embodiment will be described with reference to FIGS. FIG. 1 is a perspective view showing the internal structure of the seat back 2. FIG. 2 is a configuration diagram illustrating the operation mechanism of the headrest 3 in a side view. 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 an enlarged configuration diagram showing the fixed state of the lower end of the cable member 24. FIG. 7 is a side view showing a deformation mode of the formed wire 21. FIG. 8 is a configuration diagram showing a mounting structure between the inner cable 24a and the damper 25. As shown in FIG.
Here, in FIGS. 3 to 5, 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 the skin structure of the headrest 3 and the seat back 2 is described, FIG. 2 will be referred to as appropriate.

  As shown in FIG. 1, the headrest operating mechanism for a vehicle seat according to the present embodiment has a configuration capable of independently operating a headrest 3 that constitutes a part of the vehicle seat 1. The headrest 3 is installed on the upper part of the seat back 2, and the headrest of the occupant seated on the seat 1 is supported from the rear side while maintaining the installed posture at all times. However, as shown in FIG. 2, the headrest 3 can instantaneously move the support portion 3 a that catches the head of the occupant by the same mechanism when a rear-end collision of the vehicle occurs. Accordingly, 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 its 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 support portion 3a (see FIG. 2) 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-link mechanism 10 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 holding member 40 that can hold the four-bar linkage mechanism 10 shown in FIG. 2 in the 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 holding member 40 by this pushing operation to release the engaged state between the holding member 40 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 has a pair of left and right configurations, and the left and right movements are synchronized by long connecting shafts 10a to 10d that link the links.
Here, with reference to FIG. 2, the movable link 11 is fixed integrally with the support portion 3a. Further, the fixed link 12 has a structure integrated with a support bracket 3 c formed integrally with the stay 3 b of the headrest 3. Specifically, the fixed link 12 includes an upper arm support portion Au and a lower arm support portion Al that are formed integrally with the support bracket 3c. That is, the connecting shaft 10a is supported by the upper arm support portion Au, and the connecting shaft 10d is supported by the lower arm support portion Al. Here, the support bracket 3c corresponds to the headrest base of the present invention. The driving link 13 and the driven link 14 are link-connected to the movable link 11 and the fixed link 12 in such a manner.

  Here, the above-described stay 3b of the headrest 3 is formed in a bent shape in which the upper portion from the middle of the stay 3b is tilted forward in a dogleg shape. The stay 3 b is inserted into a support 2 s fixed to the upper frame Fu of the back frame 2 f that forms the skeleton of the seat back 2. As a result, the headrest 3 is held as being installed on the upper portion of the seat back 2. Further, as shown in FIG. 4, the support bracket 3c is formed in a U-shaped cross section, and is welded by sandwiching the upper end portion of the stay 3b inclined forward into the U-shape. It is fixed integrally. The support bracket 3 c is fixed to the stay 3 b with the U-shaped opening facing the back of the headrest 3. As a result, the U-shaped groove is not installed on the occupant's head.

Two tension springs Sa are spanned between the connecting shaft 10a and the connecting shaft 10c of the four-bar linkage mechanism 10. This tension spring Sa urges the four-bar linkage 10 in the forward rotation direction. Here, the rotational direction of travel of the four-bar link mechanism 10 is a direction in which the driving link 13 rotates clockwise about the connecting shaft 10d as seen in FIG.
Further, the driving link 13 is integrally formed with an engaging arm portion 15 having a shape in which an arm further extends from a connecting portion (connecting shaft 10 d) with the fixed link 12. The engaging arm portion 15 has a pair of left and right structures, but is formed as an integral part connected to each other. A shaft support member 30 is disposed at a position spaced rearward from the connecting shaft 10d. The shaft support member 30 is supported so as to be pivotable with respect to the lower arm support portion Al, and has a positional relationship in which the shaft center is eccentric in the radial direction with respect to the connecting shaft 10d. A cam-shaped holding member 40 that can hold the four-bar linkage 10 in an initial position by engagement is integrally fixed to the shaft support member 30. The holding member 40 is provided in a pair of left and right at both ends of the shaft support member 30. The holding member 40 is normally urged in the clockwise direction in FIG. 5 by the urging force of the tension spring Sb spanned between the support bracket 3c and is in a standing posture state indicated by a solid line. Is held on.
Here, the engaging arm portion 15 described above is formed with a locking surface 15 a that can contact the cam-shaped holding member 40 and a contact surface 15 b that can contact the shaft support member 30. . The former locking surface 15 a is formed with its surface facing the rotation direction of the engaging arm portion 15. When the holding member 40 is in an upright posture state (solid line state), the locking surface 15a engages in such a manner that it is abutted against the locking surface 15a. As a result, the rotation of the four-bar linkage mechanism 10 in the traveling direction is restricted via the engagement arm portion 15. Further, the latter contact surface 15b is formed in a concave shape that is curved so as to receive the shaft support member 30. The abutment surface 15b abuts on the shaft support member 30 when the engagement state between the engagement surface 15a and the holding member 40 is released and the engagement arm portion 15 rotates in the advancing direction (virtual line state). ). Thereby, the 4 link mechanism 10 will be in the state by which the rotation to the advancing direction was controlled.

Here, as shown in FIG. 2, the rotation of the four-bar linkage mechanism 10 in the traveling direction (arrow direction) is restricted by the shaft support member 30, that is, the support portion 3a has moved to the collision corresponding position. Then, the posture state of the four-bar linkage 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 causes the receiving load that receives the head of the occupant by the support portion 3 a to push the four-bar link mechanism 10 in the traveling direction that is regulated by the contact with the shaft support member 30. It is in the posture state to act as.
Therefore, when a rear-end collision of the vehicle occurs, even if a receiving load that catches the occupant's head accompanying the rearward tilt 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 to.

Next, the release operation mechanism 20 will be described.
That is, as shown in FIG. 1, the release operation mechanism 20 includes a formed wire 21, a bending spring 22, a clip 23, a cable member 24, and a damper 25. Here, the formed wire 21 corresponds to the oscillator of the present invention, and the bending spring 22 corresponds to the biasing member of the present invention. Each of these members is disposed inside the shape of the seat back 2.

Here, as shown in FIG. 1, the back frame 2f is formed in a gate-shaped frame shape by rigidly coupling the above-described upper frame Fu and both side frames Fs and Fs. An upper reinforcing plate 2u, a lower reinforcing plate 2t, and a reinforcing member 2r are rigidly coupled integrally with the back frame 2f. The upper reinforcing plate 2u, the lower reinforcing plate 2t, and the reinforcing member 2r are welded to the side frames Fs and Fs so as to be bridged between the side frames Fs and Fs, and are integrally fixed.
Specifically, the upper reinforcing plate 2u is fixed immediately below the upper frame Fu, with the plate surface facing forward.
The lower reinforcing plate 2t is fixed at a rear position on the lower end side of both side frames Fs, Fs with the plate surface facing forward.
The reinforcing member 2r is formed in a curved plate shape, and is fixed integrally with the lower reinforcing plate 2t at a position in front of the lower reinforcing plate 2t with the curved plate facing upward (see FIG. 7). ). Specifically, returning to FIG. 1, the reinforcing member 2r is disposed so as to cover the periphery of the operating shaft 4a provided between the side frames Fs and Fs from the front side and the lower side. Has been. Here, the operating shaft 4a is a component of the reclining mechanism 4 that operates so that the backrest angle of the seat back 2 can be changed. The operation shaft 4a is supported so as to be rotatable between the side frames Fs and Fs, and is rotated when the operation state of the reclining mechanism 4 is switched. As shown in FIG. 7, the operating shaft 4 a has a lower end side retracted position that is spaced downward from a load acting portion (for example, a portion indicated by P in the figure) of the backrest load of the occupant in the seat back 2. Is provided. Therefore, since the operation shaft 4a is not easily affected by the backrest load, it is difficult to bend and deform when a rear collision of the vehicle occurs. Similarly, the reinforcing member 2r disposed on the lower side of the operating shaft 4a is hardly affected by the backrest load. This reinforcing member 4a protects an assembly member (not shown) such as a back pad assembled to the back frame 2f from interfering with the operation shaft 4a.

Next, the configuration of the above-described formed wire 21 will be described in detail. That is, as shown in FIG. 1, the formed wire 21 is formed as a long linear member that extends over a band in the vertical direction within the frame of the back frame 2f. The formed wire 21 is formed in a single line in a downward gate shape by bending one linear member in some places.
The formed wire 21 formed in the downward gate shape has a pair of upper end portions 21u and 21u extending straight upward and connected to the front side of the upper reinforcing plate 2u. Specifically, the pair of upper end portions 21u and 21u are connected to the upper reinforcing plate 2u via the clips 23 and 23 attached to the upper reinforcing plate 2u from the front side. Here, in each of the clips 23 and 23, insertion holes 23h and 23h through which the upper end portions 21u and 21u formed in a line shape of the formed wire 21 can be inserted from below are formed. ing. These insertion holes 23h and 23h are formed in such a size that the linear upper end portions 21u and 21u can be smoothly inserted and removed from the lower side. Therefore, in the state in which the upper end portions 21u and 21u are inserted through the clips 23 and 23, the formed wire 21 is allowed to move in the vertical direction with respect to the upper reinforcing plate 2u. It is set as the connection state by which the movement to the front-back direction of upper end part 21u and 21u was controlled in the connection site | part inserted.

Further, the lower end portion 21t of the formed wire 21 is elastically supported with respect to the lower reinforcing plate 2t by a pair of bending springs 22 and 22 provided at both left and right ends thereof. As a result, the formed wire 21 is held in the initial posture position shown by the solid line in FIG. 7 in a free state where it does not receive a pressing force to the rear side thereof. Here, the bending spring 22 corresponds to the biasing member of the present invention. The bending spring 22 is formed in a dogleg shape in a side view, and a forearm portion 22f formed by bending from the front end side of the dogleg shape is caulked and fixed integrally with a lower end portion 21t of the formed wire 21. ing. Further, a rear arm portion 22b formed by bending from the rear end side of the bending spring 22 is hooked to a spring hook portion C formed on the lower reinforcing plate 2t.
As shown in FIG. 7, the bending spring 22 is sandwiched between the lower end portion 21 t and the lower reinforcing plate 2 t when the foamed wire 21 is pushed rearward by the backrest load of the occupant. , It bends and deforms in a manner that closes the opening of the square shape. And the bending spring 22 makes a biasing force act in the direction which pushes out the lower end part 21t of the formed wire 21 upwards with the bending deformation to the convolution direction. Therefore, as shown by the phantom line in the figure, when the formed wire 21 is moved rearward, the upper end portions 21u and 21u are moved against the clips 23 and 23 by the urging force of the bending spring 22. The whole is pushed upward while being slid upward.

By the way, as shown in FIG. 7, the above-described formed wire 21 has rigidity capable of maintaining the initial posture shape in a free state in which no pressing force is applied to the rear side thereof. Then, the formed wire 21 receives the occupant's backrest load at any part of the elongated shape, so that the entirety of the formed wire 21 is bent and deformed rearward from the connection part of the upper end parts 21u and 21u. It has become. In other words, the formed wire 21 is not locally deformed and deformed at the site where the occupant's backrest load is received, but is deformed and deformed so that the cantilever is bent and deformed, and the lower end portion 21t is rearward. The largest displacement is to the side. Further, when the backrest load pressed to the rear side of the formed wire 21 is unloaded, the formed wire 21 is returned to the original initial posture shape (the shape indicated by the solid line) again by its own elasticity. It is supposed to be.
Further, as shown in FIG. 6, a mounting plate portion 21 b is integrally formed at the lower end portion 21 t of the formed wire 21 so as to protrude rearward. And the lower end of the outer cable 24b of the cable member 24 is integrally fixed to this attachment plate part 21b. The lower end of the outer cable 24b is fixed in position by fitting a constricted portion formed at the end thereof from the outside of the long hole-shaped slide opening Ml formed in the mounting plate portion 21b and sliding it to the inside. Yes.

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 side (corresponding to one end side of the present invention) of the cable member 24 is disposed inside the shape of the seat back 2, and the upper end side (corresponding to the other end side of the present invention) is arranged. As shown in FIG. 2, the headrest 3 is disposed in the shape of the headrest 3 by being inserted into the stay 3 b.
More specifically, the lower end of the outer cable 24b is fixed integrally with the lower end portion 21t of the formed wire 21 as described above, and the lower end of the inner cable 24a is fixed integrally with the front portion of the reinforcing member 2r. Has been. Specifically, at the lower end of the inner cable 24a, the protruding portion formed at the end is fitted into the large diameter portion of the slide hole H having a large and small hole diameter formed in the reinforcing member 2r and slid to the small diameter portion. The position is fixed by. As shown in FIG. 7, the lower end of the inner cable 24a is fixed at the front and lower positions with respect to the fixed position of the lower end of the outer cable 24b. The fixing position of the lower end of the inner cable 24a may be directly below the fixing position of the lower end of the outer cable 24b.
Further, as shown in FIG. 1, the upper end of the outer cable 24b is integrally fixed to a mounting plate portion T formed so as to protrude forward from the upper reinforcing plate 2u. The upper end of the outer cable 24b is fixed in position by fitting a constricted portion formed at the end from the outside of the long hole-shaped slide port Mu formed in the mounting plate T and sliding it to the inside. Yes.

That is, as shown in FIG. 7, the lower end of the outer cable 24 b is fixed to the lower end portion 21 t having the largest displacement amount in the formed wire 21. And the lower end of the inner cable 24a is being fixed to the reinforcement member 2r provided in the lower end side retraction position which is hard to receive the effect | action of a passenger | crew's backrest load. Thereby, the lower end of the inner cable 24a is a position where the lower end of the outer cable 24b does not change position from the position where the reinforcing member 2r is disposed, while the lower end portion 21t of the formed wire 21 greatly moves rearward. It is held in a fixed state.
Therefore, the cable member 24 is pulled by an operation in which the formed wire 21 is pushed rearward, and transmits the movement in which the formed wire 21 is bent and deformed to the holding member 40 as an axial pulling motion. That is, when the formed wire 21 is pushed rearward, the lower end of the outer cable 24b moves away from the lower end of the inner cable 24a relatively backward and upward. As a result, the lower end side of the inner cable 24a is drawn out relative to the outer cable 24b, 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, the holding member 40 is pulled against the urging force of the tension spring Sb by pulling the inner cable 24 a on the upper end side. That is, the holding member 40 is rotated in the counterclockwise direction in the drawing. As a result, the holding member 40 is released from the engaged state with the locking surface 15a of the engaging arm portion 15 as indicated by the phantom line in FIG. The holding member 40 is returned to the standing posture again by the urging force of the tension spring Sb when the form wire 21 is released from the pushing state. Therefore, the holding member 40 is automatically engaged with the locking surface 15a of the engaging arm portion 15 by performing an operation of returning the four-bar linkage mechanism 10 rotated in the traveling direction to the initial position.

Here, as shown in FIG. 1, a damper 25 is attached to the front side of the upper reinforcing plate 2u. The damper 25 is provided so as to be interposed in the middle of the path of the inner cable 24a fed from the upper end side of the outer cable 24b. Here, the internal structure of the damper 25 is shown in FIG.
As shown in the figure, the damper 25 includes a cylindrical portion 25a filled with silicone oil (viscous material) therein, and a shaft portion 25b assembled so as to be slidable in the vertical direction with respect to the cylindrical portion 25a. Have. An inner cable 24a coming from the upper side is connected to the upper surface side of the former cylindrical portion 25a. Further, an inner cable 24a coming from the lower side is connected to the lower end side of the latter shaft portion 25b. In the damper 25, the internal space of the cylindrical portion 25a is vertically divided by a partition plate 25c formed on the upper end side of the shaft portion 25b, and silicon oil is applied to the partition plate 25c as the shaft portion 25b moves up and down. It circulates through the formed circulation hole 25f. That is, relative movement of the shaft portion 25b relative to the tube portion 25a is allowed by movement of the silicone oil flowing through the flow hole 25f. The partition plate 25c is normally urged and held at an upper position indicated by a solid line by a compression spring 25e provided between the partition plate 25a and the cylinder portion 25a.
The partition plate 25c is provided with an on-off valve 25d that can open and close the lower opening of the flow hole 25f. The on-off valve 25d is normally held in a state where the lower opening of the flow hole 25f is released. The on-off valve 25d is pressed by the viscous resistance of the silicone oil that attempts to flow upward through the flow hole 25f by the lower inner cable 24a being pulled downward at a high speed. The opening of the hole 25f is closed from below. As a result, the downward movement of the shaft portion 25b relative to the cylindrical portion 25a is restricted, and the lower inner cable 24a and the upper inner cable 24a are integrally pulled downward. .
In addition, when the lower inner cable 24a is pulled downward at a low speed, the on-off valve 25d has a small pressing force due to the viscous resistance of the silicone oil, so that the flow hole 25f remains open. Maintain state. Therefore, since the downward movement of the shaft portion 25b relative to the cylindrical portion 25a is allowed, the upper inner cable 24a is not pulled even when the lower inner cable 24a is pulled.
In the present embodiment, a shocking and large backrest load is generated by the occurrence of a rear-end collision of the vehicle, and the on-off valve 25d is closed against the movement in which the inner cable 24a is about to be pulled at a high speed. Is set to be. The opening / closing valve 25d is set so as not to be closed against a movement in which the inner cable 24a tends to be pulled at a low speed due to a backrest load caused by normal seating use. That is, during normal seating use, even if a relatively large backrest load that pulls the inner cable 24a is applied, the movement of the pulled inner cable 24a can be absorbed inside the damper 25. Therefore, it can restrict | limit so that the holding member 40 may not operate | move.

Next, the usage method of a present Example is demonstrated.
That is, as shown by the phantom lines in FIG. 2, in the normal initial state of the headrest 3, the support portion 3a is held in the initial position. Referring to FIG. 7, when a rear collision of the vehicle occurs, the back of the occupant is greatly pressed against the seat back 2 with the momentum, and the formed wire 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 40 is released. Thus, the four-joint link mechanism 10 is rotated in the traveling direction (arrow direction) to the position where the contact surface 15b of the engagement arm portion 15 contacts the shaft support member 30 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. 2, since the support portion 3 a has moved to the collision-corresponding position (solid line position), the receiving load accompanying the rearward tilt of the head applied to the support portion 3 a It acts as a pressing force for rotating in the traveling direction regulated by the material 30. 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). Thereby, as shown in FIG. 5, the locking surface 15 a of the engaging arm portion 15 can be automatically engaged with the holding member 40 biased in the standing posture state (solid line state), The support 3a can be held in the initial position again.

Thus, according to the vehicle seat headrest operating mechanism of this embodiment, the lower end of the outer cable 24b is fixed to the lower end portion 21t of the formed wire 21, and the lower end of the inner cable 24a is retracted to the lower end side of the back frame 2f. By fixing to the reinforcing member 2r provided at the position, the pulling operation of the cable member 24 can be efficiently performed at the time of rear collision of the vehicle. Therefore, the operation of switching the operating state of the active headrest at the time of a rear collision of the vehicle can be stably performed.
Furthermore, by adopting the reinforcing member 2r as a fixing member for fixing the lower end of the inner cable 24a, the lower end of the inner cable 24a can be suitably held and the configuration can be rationalized. Furthermore, the cable member 24 can be pulled more efficiently because the formed wire 21 is pushed upward when moving the rear side thereof.

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 formed wire. 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.
Moreover, the engagement arm part which controls the rotation to the advancing direction of a 4-joint link mechanism may be formed in the driven link side. In addition, although an engaging arm part may be formed in a movable link and a stopper member may be provided in the adjacent motive link or driven link, there exists a possibility that a structure may become complicated.
Further, the four-bar link mechanism is shown in a posture state in which the driving link and the driven link are both directed upward from the horizontal in the posture state in which the rotation in the traveling direction is restricted by the stopper member. 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.
Alternatively, the lower end side of the cable member may be disposed in an upwardly folded state, the lower end of the outer cable may be fixed to the reinforcing member, and the lower end of the inner cable may be fixed to the lower end portion of the formed wire.
Further, although the configuration is shown in which the formed wire as the rocking body is pushed and moved upward when moving backward, it may be configured not to move upward. Examples of such a configuration include a configuration in which the upper end portion of the formed wire is rigidly connected or hinged to the upper reinforcing plate. In this case, a bending spring as an urging member is not necessary. Moreover, although the upper end portion of the oscillator is connected to the upper reinforcing plate in a state where movement in the front-rear direction is restricted, the upper end portion also moves rearward when it receives backrest. It may be configured to.
In addition, although a formed wire capable of bending deformation formed by bending a single linear member in some places as an oscillating body is shown, it may be constituted by a planar member such as a plate member, You may be comprised by the member of a rigid body. However, when the rocking body is formed of a rigid member, the upper end portion of the swinging body needs to be hinged to the upper reinforcing plate so as to be rotatable at least. Furthermore, an urging means for urging the swinging body toward the posture state at the initial position is separately required.
Further, the fixing member for fixing the lower end of the inner cable may be any member as long as it is disposed at the lower end side retracting position that is not easily affected by the passenger's backrest load, and is limited to the reinforcing member shown in the above embodiment. Is not to be done.

It is a perspective view showing the internal structure of a seat back. It is the block diagram which represented the action | operation mechanism of the headrest by the side view. 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 block diagram which expanded and represented the fixing state of the lower end of a cable member. It is a side view showing the deformation | transformation aspect of the formed wire. It is a block diagram showing the attachment structure of an inner cable and a damper.

Explanation of symbols

1 seat 2 seat back 2f back frame 2s support 2u upper reinforcing plate 2t lower reinforcing plate 2r reinforcing member 3 headrest 3a support portion 3b stay 3c support bracket (headrest base)
DESCRIPTION OF SYMBOLS 4 Reclining mechanism 4a Actuating shaft 10 Four-node link mechanism 10a-10d Connecting shaft 11 Movable link 12 Fixed link 13 Driving link 14 Driven link 15 Engaging arm part 15a Locking surface 15b Contact surface 20 Release operation mechanism 21 Formed wire ( Oscillator)
21u Upper end portion 21t Lower end portion 21b Mounting plate portion 22 Bending spring (biasing member)
22f Forearm part 22b Rear arm part 23 Clip 23h Insertion hole 24 Cable member 24a Inner cable 24b Outer cable 25 Damper 25a Tube part 25b Shaft part 25c Partition plate 25d Open / close valve 25e Compression spring 25f Flow hole 30 Shaft support member 40 Holding member Sa Tension spring Sb Tension spring Fs Side frame Fu Upper frame Au Upper arm support part Al Lower arm support part T Mounting plate part Mu Slide port Ml Slide port H Slide hole P Load application site of backrest load C Spring hook

Claims (3)

A vehicle seat headrest actuating mechanism comprising 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,
An oscillating body disposed inside the shape of the seat back;
A cable member that connects the rocking body and the moving means, and transmits the movement of the rocking body to the moving means as a push-pull movement;
The rocking body is formed as a member extending in the vertical direction inside the shape of the seat back, and is mounted on a back frame that forms a skeleton of the seat back. By receiving a backrest load that presses against the seat back, the rocking body is pushed and moved rearward, and the lower end portion thereof is displaced most greatly to the rear side,
The cable member has a configuration in which a flexible inner cable is inserted into a tubular flexible outer cable, and the length of the inner cable with respect to the outer cable on one end side is set. By being changed, the inner cable on the other end side is pushed and pulled, and the moving means is operated along with the pushing and pulling operation of the inner cable so that the support portion collides from the initial position at the normal time. It can be moved to the corresponding position,
The other end side of the outer cable is in a fixed state integrated with the seat back,
The other end side of the inner cable is hooked to the moving means so as to be capable of being pushed and pulled,
One end side of the outer cable is integrally fixed with a lower end portion of the rocking body,
One end side of the inner cable is hooked to a fixing member provided integrally with the back frame at a position spaced downward from a lower end portion of the rocking body. Actuation mechanism. The vehicle seat headrest operating mechanism according to claim 1,
An operating shaft of a reclining mechanism that operates so that a backrest angle of the seat back can be changed is arranged at a lower end portion of both side frames constituting the back frame so as to be spanned between the side frames. And
Further, between the side frames, interference between an assembly member such as a back pad assembled to the back frame and the operating shaft of the reclining mechanism is avoided, and the support strength between the side frames is reinforced. Reinforcing members with supporting strength that can be fixed integrally with both side frames,
A headrest operating mechanism for a vehicle seat, wherein a fixing member provided integrally with a back frame on which a lower end of the inner cable is hooked is the reinforcing member. A vehicle headrest operating mechanism according to claim 1 or 2,
An urging member is provided between the lower end portion of the oscillating body and the back frame to urge the lower end portion of the oscillating body in an initial position before being pushed backward. And
The urging member is adapted to apply an urging force that pushes the oscillating body upward as the oscillating body moves backward.
The headrest operating mechanism for a vehicle seat, wherein the swinging body is mounted such that an upper end portion thereof is movable in a vertical direction with respect to the back frame.

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