JP4343818B2 - Vehicle seat - Google Patents

Description

  The present invention relates to a vehicle seat having a headrest.

In order to restrain an occupant's head at the time of a rear-end collision of a vehicle, a movable headrest device that moves the headrest forward at the time of a collision has been proposed. For example, there is provided a headrest device in which a pressure receiving plate is provided at a lower portion of a bracket that supports a headrest stage, and the bracket rotates in the front-rear direction about an axis positioned between the headrest and the pressure receiving plate. Are known. In this type of headrest device, the headrest moves forward when the occupant is pressed against the seat back by a collision and the pressure receiving plate is pushed backward. (See Patent Document 1 below)
The headrest device described in Patent Document 1 has a small amount of forward movement of the headrest with respect to the amount of movement of the pressure receiving plate, so that it is difficult to restrain the head at an early stage, and the failure reduction effect is small. If the center of rotation is set downward, the operating speed of the headrest increases, and the head can be restrained early. However, the headrest step is greatly increased backward due to the load input when restraining the head. Since it will bend, the obstacle reduction effect will fall. Increasing the rigidity of the stage to reduce the deflection of the stage causes a problem that the weight of the stage increases.

There is also a headrest device that increases the ratio (link ratio) of the distance from the center of rotation of the headrest to the headrest and the distance from the center of rotation of the headrest to the pressure plate by disposing the pressure receiving plate on the upper part of the seat back. Proposed. (See Patent Document 2 below)
JP-A-11-268565 JP 2001-58533 A

  In Patent Document 1, since the headrest and the pressure receiving plate move like a seesaw in directions opposite to each other with the axis between the headrest and the pressure receiving plate as a rotation center, the components are large and heavy. Tend to be. In addition, it takes time to assemble the seat back, and in the case of a power seat, it is necessary to dispose a movable part such as a pressure receiving plate so as not to interfere with the motor and power seat mechanism parts. Bad attachment.

  Even if the pressure receiving plate is disposed above as described in Patent Document 2, it is insufficient for early restraining of the head. In addition, when the pressure receiving plate is arranged on the upper part of the seat back, it is necessary to arrange the pressure receiving plate on the rear side in the thickness direction of the seat back as much as possible in order to prevent the pressure receiving plate from causing a foreign object feeling. is there. In that case, there arises a problem that the operation start time is delayed.

  Further, as in Patent Document 2, when the pressure receiving plate is provided at a relatively upper portion of the seat back and the pressure receiving plate is pushed by the back of the occupant, the pressure receiving plate is disposed at the lower portion of the seat back. The load input to the pressure receiving plate is smaller than that of the existing structure. Moreover, there is a problem that the start of operation is further delayed because the seat back frame itself bends backward.

  In order to solve these problems, the present inventors accommodate a speed increasing unit that speeds up the movement of the pressure receiving member inside the seat back, and outputs the output of the speed increasing unit via a wire to a headrest driving mechanism. A vehicle seat having a structure to be transmitted to the vehicle was considered. The speed increasing unit has a contact member such as a roller disposed on the back side of the pressure receiving member, and when the pressure receiving member moves rearward, the contact member is pushed so that the wire is pulled. It is configured.

  However, since the pressure receiving member is pushed almost horizontally by the back of the occupant, in the case where the lower side of the link mechanism constituting the speed increasing unit is moved downward by the guide means, the backward movement of the pressure receiving member is efficiently performed. There is a concern that the transmission cannot be transmitted to the link mechanism, and the operation of the headrest may be hindered.

  Accordingly, an object of the present invention is to provide a vehicle seat provided with a speed increasing unit capable of quickly and reliably operating a headrest at the time of a collision.

  The vehicle seat according to the present invention includes a seat back having a seat back frame, a headrest provided at an upper portion of the seat back, and an upper portion of the seat back frame that is movable in the vertical direction and tiltable in the front-rear direction. A support bracket for inserting the stage, a pressure receiving member that is provided on the seat back and moves rearward when pushed by an occupant, a wire that has one end and the other end and is disposed on the seat back, and the wire One end of the wire is connected, and when the pressure receiving member moves rearward, the speed increasing unit that accelerates the movement of the pressure receiving member to drive the wire in a pulling direction is connected to the other end of the wire, A headrest drive mechanism that tilts the support bracket to the front side while moving the support bracket upward when pulled.

  The speed increasing unit includes a base bracket provided on the seat back frame to which the one end of the wire is connected, and a first arm and a second arm that are rotatably connected to each other. An upper end portion of the arm is supported so as to be rotatable in the front-rear direction with respect to the base bracket, and a lower end portion of the second arm is movable in the vertical direction with respect to the base bracket. A link mechanism in which the connecting portion of the arm protrudes in the direction of the pressure receiving member, an abutting member provided at the connecting portion of the first arm and the second arm, and a lower end portion of the second arm. And the guide pulley for winding the wire and the second arm so that the angle formed by the first and second arms is large when the contact member is pushed backward by the pressure receiving member. Are provided with guide means for guiding the end.

  The pressure receiving member has a convex portion provided facing the contact member of the speed increasing unit, and the convex portion has a tapered surface inclined so that the upper side protrudes toward the contact member side rather than the lower side. And when the pressure receiving member moves rearward, the tapered surface abuts against the abutting member, thereby generating a downward component force at the corresponding contact portion.

In one form of this invention, the said contact member is a roller which roll-contacts to the said taper surface.
The convex portion is formed by extruding a part of the pressure receiving member made of, for example, a metal plate by a press.
An example of the convex portion has a substantially right triangle shape having the tapered surface and an upper side continuous with the tapered surface as viewed from the side surface direction of the pressure receiving member, for example.

  Another example of the convex portion has a substantially isosceles triangular shape having the tapered surface and an inclined surface connected to the tapered surface when viewed from the side surface direction of the pressure receiving member. Moreover, the flange part which suppresses that the said roller moves to the width direction of this taper surface may be provided in the width direction both sides of the taper surface of the said convex part.

  According to the present invention, when the pressure receiving member moves rearward due to a collision, the movement of the pressure receiving member is accelerated by the speed increasing unit and transmitted to the headrest tilting mechanism via the wire, so that there is no operation delay. The head of the occupant can be restrained promptly. Further, by providing a convex portion on the pressure receiving member and forming the tapered surface on the convex portion, a downward component force can be generated at the corresponding contact portion when the pressure receiving member pushes the contact member backward. Therefore, the lower side of the link mechanism constituting the speed increasing unit can be assisted to move downward by the guide means, and the speed increasing unit can be functioned quickly and reliably at the time of a collision.

A first embodiment of the present invention will be described below with reference to FIGS.
FIG. 1 shows a vehicle seat 10. The vehicle seat 10 includes a seat portion 11, a seat back 12, and a headrest 13. The headrest 13 includes a headrest main body 14 provided on the upper portion of the seat back 12 and a pair of left and right stages 15 extending below the headrest main body 14.

  2 and 3 show the interior of the seat back 12. The seat back 12 includes a seat back frame 20, a spring assembly 21, a pad member 22 (shown by a two-dot chain line in FIG. 3) arranged to cover the spring assembly 21, and a cover member that covers the outer surface of the pad member 22. 23 (shown in FIG. 1).

  The seat back frame 20 includes a pair of left and right side frame members 30 and 31, an upper frame member 32 positioned on the upper side, a lower frame member 33 positioned on the lower side, and the like. The side frame members 30 and 31 and the lower frame member 33 are formed into a predetermined shape by pressing a metal plate. The upper frame member 32 is made of a pipe having a circular cross section, for example, and both ends thereof are welded to the upper portions of the side frame members 30 and 31. Both ends of the lower frame member 33 are welded to lower portions of the side frame members 30 and 31.

  An example of the spring assembly 21 includes a flat spring 35 and a plurality of tension springs 36. The flat spring 35 is constituted by a plurality of vertical wires 37 extending in the vertical direction and horizontal wires 38 extending in the horizontal direction. Both side portions of the flat spring 35 are supported on the side frame members 30 and 31 by a tension spring 36.

  As shown in FIG. 2, two systems of cables 41 and 42 are arranged inside the seat back 12. FIG. 3 shows one cable 41 as a representative. Each of these cables 41, 42 has an outer tube 43 and a wire 44 inserted into the outer tube 43. The wire 44 is an example of a rope body, and is configured by twisting a plurality of strands.

  The intermediate portions in the longitudinal direction of the cables 41 and 42 are supported by, for example, the upper frame member 32 by a retainer 45 (shown in FIG. 3). As shown in FIGS. 2 and 3, the outer tube 43 has one end 43a and the other end 43b. The wire 44 also has one end 44a and the other end 44b.

  As shown in FIGS. 2 and 3, long hole brackets 51 each having a guide hole 50 are provided at both ends of the upper frame member 32 of the seat back frame 20. The guide hole 50 extends obliquely in the vertical direction so that one end 50a thereof is located in front of and lower than the other end 50b. A subframe 55 is provided between the pair of long hole brackets 51.

  The subframe 55 includes a horizontal portion 56 extending in the horizontal direction and a pair of arm portions 57 formed at both ends of the horizontal portion 56. The arm portion 57 extends obliquely downward and forward from both ends of the horizontal portion 56. A slide member (for example, a slide pin) 58 is provided at the end of each arm portion 57. The slide member 58 is inserted into the guide hole 50 of the long hole bracket 51 and comes into contact with the upper side portion 50c of the guide hole 50 at a contact C2 (shown in FIG. 4). The slide member 58 can move in the vertical direction (longitudinal direction of the guide hole) along one end 50 a and the other end 50 b of the guide hole 50 along the guide hole 50.

  The lower portions of the pair of left and right support brackets 60 are fixed to the horizontal portion 56 of the subframe 55. The stage 15 of the headrest 13 is inserted into each support bracket 60. The support bracket 60 has a cylindrical shape, and a grommet 61 is provided at the upper end. A sliding guide bracket 65 is provided on the upper frame member 32. The sliding guide bracket 65 is provided with a sliding guide member 66 (shown in FIG. 2) made of synthetic resin at a portion in contact with the support bracket 60.

  The support bracket 60 can smoothly slide in the vertical direction with respect to the upper frame member 32 by the sliding guide member 66. As shown in FIG. 4, the back surface 60 a of the intermediate portion in the vertical direction of the support bracket 60 is supported by the sliding guide bracket 65 so as to contact the upper frame member 32 at the contact C <b> 1. In addition, the support bracket 60 has a sliding guide bracket 65 and an upper frame member so that the support bracket 60 can be inclined in a range of a certain angle θ1 (shown in FIG. 3) in the front-rear direction with the contact C1 with the upper frame member 32 as a fulcrum. 32 and is supported so as to be tiltable.

  The long hole bracket 51, the subframe 55, the slide member 58, the support bracket 60, the sliding guide bracket 65, and the like constitute a headrest driving mechanism 67 for supporting the headrest 13 so as to be tiltable in the front-rear direction. ing.

  In the headrest drive mechanism 67, the headrest body 14 and the support bracket 60 move upward when the slide member 58 moves obliquely upward and backward along the guide hole 50 (in the direction indicated by the arrow A in FIGS. 3 and 4). However, the positions of the contact points C1 and C2, the length of the arm portion 57 of the sub-frame 55, the angle θ2 (shown in FIG. 3) formed by the arm portion 57 and the support bracket 60, etc. are set so as to incline forward. Yes.

  The stage 15 of the headrest 13 is inserted into the support bracket 60 from the hole of the grommet 61. Each of the stages 15 is movable in the vertical direction with respect to the support bracket 60. The stage 15 is fixed to the support bracket 60 by a lock mechanism (not shown) in a state where the headrest body 14 is adjusted to a desired height.

  A pressure receiving member 70 is provided inside the seat back 12 so as to be positioned below the spring assembly 21, that is, behind the waist of the occupant (seater). The pressure receiving member 70 is attached to the spring assembly 21. When the spring assembly 21 is pushed by the occupant and bent backward, the pressure receiving member 70 can move together with the spring assembly 21 from the front side position toward the rear side position. A convex portion 71 protruding rearward is formed on a part of the pressure receiving member 70.

  The convex portion 71 formed on the pressure receiving member 70 is provided at a position facing the roller 95 of the speed increasing unit 79 described below. The convex portion 71 has a tapered surface 72 inclined so that the upper side protrudes toward the roller (contact member) 95 side from the lower side. By providing such a tapered surface 72, when the pressure receiving member 70 moves rearward, the tapered surface 72 contacts the roller 95, thereby generating a downward component force F <b> 1 at the contact portion with the roller 95. .

  The convex portion 71 is formed by extruding a part of a pressure receiving member 70 made of a metal plate by a press. As shown in FIG. 7, the convex portion 71 has the tapered surface 72 and the upper side 73 connected to the tapered surface 72 as viewed from the side of the pressure receiving member 70, and is generally in the shape of a right triangle. As shown in FIG. 5, an opening 76 is formed on the upper surface side of the convex portion 71.

  A speed increasing unit 79 is provided at a position facing the rear surface of the pressure receiving member 70. The speed increasing unit 79 includes a base bracket 80 fixed to the lower frame member 33, and a first arm 81 and a second arm 82 provided on the base bracket 80. The speed increasing unit 79 has a vertical orientation in which the first arm 81 is located on the upper side and the second arm 82 is located on the lower side, that is, the longitudinal direction of the base bracket 80 is the vertical direction. Is arranged on the lower frame member 33 in a posture along

  As shown in FIGS. 3, 6, and 7, one end 43 a of each outer tube 43 of the pair of cables 41 and 42 is connected to the cable support portion 85 of the base bracket 80. One end 44 a of each wire 44 of the cables 41 and 42 is connected to the wire support portion 86 of the base bracket 80.

  One end (upper end) of the first arm 81 is supported by the first pin 90 so as to be rotatable in the front-rear direction with respect to the base bracket 80. The first pin 90 is an example of a first shaft. The base bracket 80 is provided with a guide roller 91 that can rotate around the first pin 90.

  The first arm 81 and the second arm 82 are pivotally connected to each other by a second pin 92, and the connecting portion of the first arm 81 and the second arm 82 protrudes toward the pressure receiving member 70. Yes. That is, these arms 81 and 82 constitute a <shaped link mechanism 83. The angle θ3 (shown in FIG. 7) formed by the first arm 81 and the second arm 82 is preferably 90 ° or more (obtuse angle). The second pin 92 is an example of a second shaft.

  A roller 95 is provided at a connection portion between the first arm 81 and the second arm 82 constituting the link mechanism 83. The roller 95 is an example of a contact member. The roller 95 is rotatable around the second pin 92. The roller 95 is disposed so as to face the convex portion 71 protruding from the rear surface of the pressure receiving member 70. When the pressure receiving member 70 moves rearward (in the direction indicated by the arrow B in FIGS. 3 and 7), the roller 95 is disposed. Is in rolling contact with the tapered surface 72.

  At the other end (lower end) of the second arm 82, a third pin 96 and a guide pulley 97 that is rotatable around the third pin 96 are provided. The third pin 96 is an example of a third shaft. The third pin 96 is inserted into the guide hole 100 formed in the base bracket 80 and can move along the guide hole 100 in the longitudinal direction (vertical direction) of the guide hole 100.

  The third pin 96 and the guide hole 100 constitute guide means. The guide means guides the movement of the guide pulley 97 so that the angle θ3 formed by the first and second arms 81 and 82 increases when the roller 95 is pushed rearward by the pressure receiving member 70.

  When the roller 95 is pushed in the direction of arrow B in FIG. 7 by the convex portion 71, the angle θ3 formed by the first arm 81 and the second arm 82 increases as shown in FIG. Here, since the first pin 90 is supported by the base bracket 80, the third pin 96 moves downward from one end (upper end) 100a of the guide hole 100 toward the other end (lower end) 100b. For this reason, the distance from the 1st pin 90 to the 3rd pin 96 becomes large gradually. That is, the guide pulley 97 moves downward along the guide hole 100.

  The guide hole 100 has a first portion 101 located on the side close to the first pin 90 and a second portion 102 located on the side far from the first pin 90. The first portion 101 extends obliquely downward and rearward at an angle θ4 with respect to an extension line L1 (shown in FIG. 7) connecting the first pin 90 and the third pin 96. The second portion 102 is bent to the opposite side (obliquely lower front) to the first portion 101 with respect to the extension line L1.

  For this reason, when the guide pulley 97 moves along the guide hole 100 from the one end 100 a of the guide hole 100 toward the other end 100 b, the third pin 96 can easily move along the first portion 101. When the third pin 96 moves along the second portion 102, the moving speed of the guide pulley 97 becomes higher than when the first portion 101 moves.

  As shown in FIGS. 6 to 8, a part 44 c of each wire 44 of the pair of cables 41 and 42 is in contact with a part of the guide roller 91. A portion 44d on the other end side of each wire 44 is wound around the guide pulley 97 positioned below it by about a half circumference. In other words, the portion 44d on the other end side of the wire 44 is fixed to the wire support portion 86 of the base bracket 80 in a state where the direction is changed by approximately 180 ° (U-turn) by the guide pulley 97. Yes.

  For this reason, when the guide pulley 97 moves along the guide hole 100 from one end 100a of the guide hole 100 toward the other end 100b, the guide pulley 97 moves downward like a moving pulley, so that each wire 44 becomes The guide pulley 97 is pulled by a length corresponding to a distance twice the amount of movement. In other words, when the pressure receiving member 70 moves rearward (in the direction of arrow B), the movement of the pressure receiving member 70 is increased by the speed increasing unit 79, and the wire 44 is pulled quickly.

  The other end 44 b (shown in FIG. 3) of each wire 44 of the pair of cables 41 and 42 is connected to each slide member 58 of the headrest drive mechanism 67. Therefore, when each wire 44 is pulled in the direction indicated by the arrow D in FIG. 3 by the speed increasing unit 79, each slide member 58 of the headrest drive mechanism 67 moves in the direction indicated by the arrow A.

Next, the operation of the vehicle seat 10 having the above configuration will be described.
When the occupant is pressed against the seat back 12 at the time of the collision, the pressure receiving member 70 is pushed backward by a load input to the seat back 12 from the vicinity of the occupant's waist. As a result, the pressure receiving member 70 pushes the roller (contact member) 95 of the speed increasing unit 79, so that the angle θ3 (shown in FIG. 7) formed by the first arm 81 and the second arm 82 increases. The second arm 82 moves. At this time, when the third pin 96 provided at the lower end of the second arm 82 moves downward along the guide hole 100, the guide pulley 97 moves downward as shown in FIG.

  The convex portion 71 provided on the pressure receiving member 70 has a tapered surface 72 that is inclined so that the upper side protrudes toward the roller 95 side rather than the lower side. When contacted with the roller 95, a downward component force F1 (shown in FIGS. 7 and 8) is generated at the contact portion with the roller 95.

  This component force F1 helps the third pin 96 to move downward along the guide hole 100, so that the third pin 96 can move reliably and smoothly along the guide hole 100, As shown in FIG. 8, the guide pulley 97 moves downward.

  Since each wire 44 of the pair of cables 41 and 42 is wound around the guide pulley 97 in a U-shape about half a circumference, the guide pulley 97 has a speed approximately twice the moving speed of the guide pulley 97 according to the principle of a so-called moving pulley. The wire 44 is pulled in the direction indicated by the arrow E. For this reason, each slide member 58 of the headrest drive mechanism 67 moves in the direction shown by the arrow A in FIG.

  Since the first portion 101 of the guide hole 100 is inclined rearward at an angle θ4 with respect to the extension line L1 (shown in FIG. 7) of the first and third pins 90 and 96, the roller 95 is an arrow. When pushed in the B direction, initially, the third pin 96 moves downward along the first portion 101 while moving slightly backward. For this reason, the wire 44 can be easily pulled out from the outer tube 43.

  Thereafter, since the third pin 96 moves along the second portion 102, the drawing speed of the wire 44 increases. Such a guide hole 100 allows the wire 44 to be pulled out by changing the inclination angle θ4 of the first portion 101 or changing the angle formed by the second portion 102 with respect to the first portion 101. The speed can be adjusted.

  As described above, the pressure-receiving member 70 moves rearward at the time of a collision, and the wires 44 of the cables 41 and 42 are pulled simultaneously by the speed increasing unit 79, whereby each slide member 58 of the pair of left and right headrest drive mechanisms 67 is obtained. However, they move obliquely upward and rearward along the guide hole 50 from one end 50a to the other end 50b.

  When the slide member 58 moves along the guide hole 50 from the one end 50a toward the other end 50b, the arm portion 57 of the subframe 55 moves upward and backward. Along with this, the support bracket 60 and the headrest main body 14 move upward so as to fall forward with the contact C1 as a fulcrum. Since the contact C1 itself remains in the same position without moving forward, the headrest main body 14 moves forward and upward along a locus shown by the arrow M1 in FIG. 4 without accelerating restraint under the occupant's neck. Thus, the head is quickly restrained by the headrest body 14 before the neck is restrained.

  In the seat back 12 of the present embodiment, the backward movement of the pressure receiving member 70 is transmitted from the speed increasing unit 79 to the headrest drive mechanism 67 via the wires 44 of the pair of cables 41 and 42. Even if the distance from the speed unit 79 to the headrest driving mechanism 67 is large, the movement of the pressure receiving member 70 can be quickly transmitted to the headrest driving mechanism 67 by the wire 44.

  For this reason, even if the distance from the speed increasing unit 79 to the headrest drive mechanism 67 is relatively large, the entire apparatus including the pressure receiving member 70 and the headrest drive mechanism 67 can be configured to be lightweight. Further, it is easy to assemble the speed increasing unit 79 and the headrest drive mechanism 67 inside the seat back 12.

  Moreover, the vehicle seat 10 according to the present embodiment is configured to increase the moving speed of the pressure receiving member 70 at the time of the collision by the speed increasing unit 79 and operate the headrest driving mechanism 67 via the wire 44. Excellent and no delay in operation. Since the speed increasing unit 79 is configured independently of the pressure receiving member 70, the assembling property to the seat back frame 20 is good.

  FIG. 9 shows a pressure receiving member 70A according to the second embodiment of the present invention. The convex portion 71A of the pressure receiving member 70A has a substantially isosceles triangular shape having a tapered surface 72 whose upper side protrudes toward the roller 95 and a slope 74 continuous thereon, as viewed from the side surface direction of the pressure receiving member 70A. Yes. The protrusion 71A is stamped and formed by pressing, but does not form the upper opening 76 (shown in FIG. 5) like the protrusion 71 of the first embodiment. Also in this embodiment, when the pressure receiving member 70A moves rearward, the taper surface 72 comes into contact with the roller 95 (contact member), thereby generating a downward component force F1.

  70 A of pressure receiving members which have the convex part 71A of such a shape can increase the intensity | strength of the convex part 71A because the rigidity of the convex part 71A and its circumference becomes large. Since other configurations, operations, and effects are the same as those of the speed increasing unit 79 of the first embodiment, the same reference numerals as those of the first embodiment are used and description thereof is omitted.

  FIG. 10 shows a pressure receiving member 70B according to the third embodiment of the present invention. The convex portion 71B of the pressure receiving member 70B has a substantially right triangle shape having a tapered surface 72 and an upper side 75 connected to the tapered surface 72 when viewed from the side surface direction of the pressure receiving member 70B. This convex portion 71B is also stamped and formed by press working so as not to form the opening 76 on the upper side like the convex portion 71 of the first embodiment. The convex portion 71B having such a shape also has high strength, and the convex portion 71B can be configured compactly. Other configurations, operations, and effects are the same as those in the first embodiment and the second embodiment.

  FIG. 11 shows a pressure receiving member 70C according to the fourth embodiment of the present invention. The convex portion 71C of the pressure receiving member 70C includes flange portions 110 on both sides in the width direction of the tapered surface 72 of the convex portion 71C when viewed from above the pressure receiving member 70C. These flange portions 110 prevent the roller 95 from moving in the width direction of the tapered surface 72. With the convex portion 71 </ b> C having such a flange portion 110, the roller 95 can be prevented from coming off the tapered surface 72 when the roller 95 moves in the vertical direction along the tapered surface 72. Other configurations, operations, and effects are the same as those in the above embodiments.

The perspective view of the vehicle seat which concerns on the 1st Embodiment of this invention. The perspective view which shows the inside of the seat back of the vehicle seat shown by FIG. The side view which shows the inside of the seat back of the vehicle seat shown by FIG. The side view of the headrest drive mechanism of the seat back shown in FIG. FIG. 4 is a perspective view of a part of the seat back and the pressure receiving member shown in FIG. 3. FIG. 4 is a perspective view of a speed increasing unit for the seat back shown in FIG. 3. FIG. 4 is a side view of the speed increasing unit for the seat back shown in FIG. 3. The side view which shows the state which the speed increasing unit shown by FIG. 7 act | operated. The side view of the speed increasing unit which concerns on the 2nd Embodiment of this invention. The side view of the speed increasing unit which concerns on the 3rd Embodiment of this invention. Sectional drawing which follows the horizontal direction of the pressure receiving member of the speed increasing unit which concerns on the 4th Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Vehicle seat 12 ... Seat back 13 ... Headrest 20 ... Seat back frame 44 ... Wire 60 ... Support bracket 67 ... Headrest drive mechanism 70, 70A, 70B, 70C ... Pressure receiving member 71, 71A, 71B, 71C ... Convex part 72 ... Tapered surface 79 ... Speed increasing unit 80 ... Base bracket 81 ... First arm 82 ... Second arm 83 ... Link mechanism 95 ... Roller (contact member)
97 ... guide pulley 100 ... guide hole (guide means)

Claims (6)

A seat back having a seat back frame;
A headrest provided on the upper portion of the seat back;
A support bracket that is provided on the upper portion of the seat back frame so as to be movable in the vertical direction and tiltable in the front-rear direction, and for inserting the stage of the headrest;
A pressure receiving member that is provided in the seat back and moves rearward when pressed by an occupant;
A wire having one end and the other end disposed on the seat back;
A speed increasing unit that is connected to one end of the wire and that drives the pressure receiving member in a direction to pull the wire by increasing the movement of the pressure receiving member when the pressure receiving member moves backward;
A headrest drive mechanism that is connected to the other end of the wire and tilts forward while moving the support bracket upward when the wire is pulled;
The speed increasing unit is:
A base bracket provided on the seat back frame to which the one end of the wire is connected;
The first arm and the second arm are rotatably connected to each other, and the upper end of the first arm is supported to be rotatable in the front-rear direction with respect to the base bracket. A link mechanism in which a lower end portion is movable in a vertical direction with respect to the base bracket, and a connection portion between the first arm and the second arm protrudes toward the pressure receiving member;
An abutting member provided at the connecting portion of the first arm and the second arm;
A guide pulley that is provided at a lower end portion of the second arm and winds the wire;
Guide means for guiding a lower end portion of the second arm so that an angle formed by the first and second arms is increased when the contact member is pushed backward by the pressure receiving member;
Comprising
The pressure receiving member has a convex portion provided facing the contact member of the speed increasing unit, and the convex portion has a tapered surface inclined so that the upper side protrudes toward the contact member side rather than the lower side. The vehicular seat is characterized in that when the pressure receiving member moves rearward, the tapered surface abuts against the abutting member, thereby generating a downward component force at the corresponding portion.   The vehicle seat according to claim 1, wherein the contact member is a roller that is in rolling contact with the tapered surface.   The vehicle seat according to claim 1, wherein the convex portion is formed by extruding a part of the pressure receiving member made of a metal plate by a press.   4. The vehicle seat according to claim 3, wherein the convex portion has a substantially right triangle shape having the tapered surface and an upper side continuous with the tapered surface when viewed from a side surface direction of the pressure receiving member. .   4. The vehicle according to claim 3, wherein the convex portion has a substantially isosceles triangle shape having the tapered surface and an inclined surface connected to the tapered surface when viewed from a side surface direction of the pressure receiving member. Sheet.   The vehicular seat according to claim 2, wherein flanges are provided on both sides of the convex portion in the width direction of the tapered surface to prevent the roller from moving in the width direction of the tapered surface. .

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