JP5077667B2 - Lock mechanism of headrest device - Google Patents

Description

  The present invention relates to a vehicle seat, and more particularly, to a lock mechanism for a headrest device that reduces a nuisance hitting trouble of a seated person when a vehicle is bumped from behind.

  FIG. 4 is a side view schematically showing the internal structure of a conventional headrest device. The headrest device 70 includes a headrest 36, a headrest frame 31, a pressure receiving plate 32 fixed to the lower end of the headrest frame 31, and a column 33 that supports the headrest 36. The headrest frame 31 has an inverted U shape, and is attached to the inside of the seat back frame 21 via the tilt shaft 12 so as to be tiltable in the front-rear direction. The headrest frame 31 is normally urged in the direction of the white arrow by a tilting spring 39 near the pressure receiving plate 32, whereby the upper end of the headrest frame 31 tilts rearward, and the column 33 is seated back. It is pushed to face the 21 side. The tilting spring is a coil spring that pulls the pressure receiving plate 32 forward as shown in FIG. 4 or a U-shaped bridge that spans the pressure receiving plate 32 from both sides of the seat back frame as shown in Patent Document 1. Realized by a bar spring (cantilever).

  When the vehicle is collided, the vehicle is accelerated forward by an impact, so that the seated person M is pushed backward by the vehicle seat. When the pressure receiving plate 32 receives the load of the seated person M and is pushed rearward against the tilting spring 39, the headrest frame 31 rotates about the tilting shaft 12 and tilts the headrest 36 forward. As a result, the head of the seated person M is supported by the headrest 36, and the rapid backward movement of the head that causes whiplash is prevented. The headrest 36 is preferably locked in a tilted state after the impact. Patent Document 2 discloses a lock mechanism in which a ratchet mechanism (14) is provided between a seatback frame and a headrest frame so that the headrest frame does not return to its original position after a rear-end collision. Patent Document 3 shows a lock mechanism in which a headrest frame after a rear-end collision is received by a detent stopper (81) so as not to return to the original position.

In the lock mechanism using the ratchet described above, there is a possibility that the headrest moves forward when the seated person stretches the body backward by stretching. If the teeth are incompletely engaged, the lock is weak. The locking mechanism using a detent stopper that engages with the outer periphery of the headrest frame above locks with the detent stopper so that the headrest frame does not return to its original position when it is bumped. Does not have a function of securely engaging and holding the seat back frame. Although the upper end of the headrest frame is pressed against the seat back frame and held by the force of the tilt spring, the engagement is weak by itself, so that a reliable engagement is required. Here, for example, if the tilting spring is strengthened and the countermeasure is taken, the movement of the pressure receiving plate is slowed down, so that the headrest is not easily tilted forward when the rear-end collision occurs, and this cannot be solved.
JP 2002-144938 A JP 2002-274240 A Japanese Patent Laid-Open No. 10-138813

  An object of the present invention is to provide a lock mechanism for a headrest device that can reliably maintain a normal state in which the headrest frame is engaged with a seatback frame and a locked state when the headrest frame is collided.

  In order to achieve the above object, according to the first aspect of the present invention, there is provided a locking mechanism for a headrest device, wherein the headrest is connected to the upper portion, and receives the rear load applied to the seated person when the headrest is bumped, and A headrest device having a headrest frame provided with a tilting spring for tilting and attached to the inside of the seatback frame so as to be tiltable. A base bracket having an elongated hole attached to an upper portion of the seatback frame and extending vertically on both sides. And a lock pin that is movably mounted in the elongated hole, and is attached to the upper portion of the headrest frame, and normally contacts the lock pin to restrain downward movement of the lock pin, and when it is bumped The pressure receiving plate moves backward and the headrest frame tilts forward so that the lock A stopper bracket that releases the restraint of the pin, abuts on the lock pin that has moved downward, and restrains movement to a normal position by the lock pin, one end is connected to the lock pin, and the other end is the stopper A tension spring connected to the lower end of the stopper bracket through a through-hole of the bracket and biasing the lock pin toward the stopper bracket, and a strap for returning the lock pin to a normal position. To do.

  According to the lock mechanism of the headrest device of the first aspect of the present invention, since the stopper bracket that abuts the lower portion of the lock pin and restrains the downward movement of the lock pin is provided on the upper portion of the headrest frame, Can be securely engaged with and held by the seat back frame. Since the lock pin is pulled downward by the tension spring, the holding force is improved without changing the specifications of the spring that tilts the headrest frame backward, because it is perpendicular to the rearward direction, which is the direction of the force that tilts the headrest frame backward. Can be made. When this stopper bracket is bumped, it comes into contact with the side of the lock pin that has moved downward, and the lock pin is restrained from returning to its original position. Therefore, the locked state can be reliably held. If the strap is pulled upward against the tension spring, the lock pin can be easily returned to the normal position. Since one end of the tension spring is connected to the lower end of the stopper bracket through the stopper bracket's through-hole, pulling the strap will rotate the headrest frame upward and return the headrest frame to its normal position. Since it helps, the return operation is easy.

  Hereinafter, a lock mechanism of a headrest device according to the present invention will be described with reference to the drawings.

  FIG. 1 is a normal perspective view of a lock mechanism provided in a headrest device according to the present invention. The configuration of the headrest device 70 includes a headrest 36, a headrest frame 31, a pressure receiving plate 32 fixed to the lower end of the headrest frame 31, and a column 33 that supports the headrest 36, and is the same as the configuration shown in FIG. The seat back frame 21 and the headrest frame 31 attached to the inside of the seat back frame 21 via the tilting shaft 12 so as to be tiltable are processed pipes, and all of them are curved in an inverted U shape. The lower part of the seat back frame 21 is firmly connected to the reclining mechanism. The headrest frame 31 has two support holders 11 attached to the top thereof, a support 33 is inserted into the support holder 11, and a headrest 36 is attached to the support. A pressure receiving plate 32 is provided below the headrest frame 31. A tilting spring for tilting the headrest frame 31 is attached to the rear of the pressure receiving plate 32. Here, the cantilever 34 is employed as the tilting spring, both ends of the cantilever 34 are mounted on the seat back frame 21, and the central portion of the cantilever 34 is twisted by the pressure receiving plate 32 slightly protruded rearward, so that FIG. As indicated by the downward arrow F1, the force that pushes the lower portion of the headrest frame 31 forward is biased. For this reason, the upper part of the headrest frame 31 and the column holder 11 are urged rearward as shown by an arrow F2 in the upper part of FIG.

  As shown in FIG. 1, the lock mechanism 50 includes a base bracket 1 having a long hole 5 attached to the seat back frame 21 on both sides, a lock pin 2, a stopper bracket 3 attached to the headrest frame 31, a tension spring 6, and a lock pin. 2 includes a strap 4 for pulling up 2. The tension spring 6 has one end hooked to the lock pin 2 and the other end hooked to the lower end of the stopper bracket 3 through the through hole 13 of the stopper bracket 3. In the normal state shown in FIG. 1, the lock pin 2 is positioned above the long hole 5, and the stopper bracket 3 is restrained so as not to move the lock pin 2 downward. Since the lock pin 2 is strongly pulled downward by the tension spring 6, the headrest frame 31 is held so as not to easily move from the seat back frame 21. As shown in the drawing circle, the tilting shaft mounting member 37b is connected to the tilting shaft mounting member 37a so as to be rotatable by the tilting shaft 12. The tilt shaft mounting member 37a is welded to the seat back frame 21, and the tilt shaft mounting member 37b is welded to the headrest frame. Both ends of the horizontal connecting rod 7 are attached to the seat back frame 21, and restrict the rearward inclination of the upper portion of the headrest frame 31. When the headrest frame 31 rotates, the contact portion 38 of the tilt shaft mounting member 37b contacts the forward tilt restraining portion 35 of the tilt shaft mounting member 37a, so that the forward tilt of the headrest frame is limited.

  FIG. 2 is a perspective view when the vehicle of the lock mechanism provided in the headrest device according to the present invention is collided. When the vehicle collides, the human body pushes the tilting pressure receiving plate 32 backward against the force of the cantilever 34, so that the upper part of the headrest frame 31 rotates forward. Therefore, the stopper bracket 3 that restrains the downward movement of the lock pin 2 moves forward and the restraint is released. The lock pin 2 moves downward along the long hole 5. After the impact, the upper part of the headrest frame 31 tries to return to the normal position at the rear by the urging force of the cantilever 34. However, the side surface of the stopper bracket 3 abuts on the lock pin 2 and returns to the normal position. Return is restrained. Accordingly, the headrest 36 is locked in a forwardly tilted state when the rear-end collision occurs. Since the lock pin 2 is pulled downward by the tension spring 6 and is urged rearward of the stopper bracket 3, the locked state is maintained.

  FIG. 3 is a side sectional view of the locking mechanism of FIG. (A) shows a cross-sectional view of a state where the stopper bracket restrains the lock pin in a normal state, and (B) shows a cross-sectional view of a state where the lock pin restrains the stopper bracket when the stopper bracket is impacted. . The operation of the lock mechanism 50 is as follows. Normally, the upper part of the headrest frame 31 is tilted rearward by the cantilever 34 and the lock pin 2 is urged downward by the tension spring 6, but the lower part of the lock pin 2 is placed on the step 9 of the stopper bracket 3. Are in contact with each other, and the downward movement of the lock pin 2 is restricted. Normally, the headrest frame 31 (including the headrest 36) is held at this position by both the urging force of the cantilever 34 and the urging force of the tension spring 6.

  As shown in FIG. 3 (B), when the vehicle is collided and the human body of the occupant seated M is pushed backward, the pressure receiving plate is pushed backward against the urging force of the cantilever 34. The frame 31 rotates about the tilting shaft 12. Along with this, the stopper bracket 3 on the headrest frame 31 moves forward. The stopper bracket 3 moves up to a position indicated by a dotted line. Therefore, the restraint by the stopper bracket 3 is released, and the lock pin 2 moves downward along the long hole 5 by the urging force of the tension spring 6.

  The headrest frame 31 tries to return to the normal position by the urging force of the cantilever 34 after the impact of the rear-end collision, but the lock pin 2 restrains the headrest frame 31 from moving backward. That is, the side portion 10 of the stopper bracket 3 comes into contact with the lock pin 2 that has moved downward, and its movement is blocked. That is, the stopper bracket 3 is restrained by the lock pin 2. The lock pin 2 does not move upward by the urging force of the tension spring 6, and the stopper bracket 3 is held and locked in that position by the urging force of the cantilever 34.

  The locked state is released by pulling up the strap 4 against the tension spring 6. When the lock pin 2 is pulled up, the stopper bracket 3 returns to the normal position by the urging force of the cantilever 34. When the lock pin 2 is pulled up, the lifting force assists the rotation of the headrest frame 31 via the tension spring 6.

  The lock mechanism according to the present invention is suitable for a headrest device for a vehicle seat.

It is a perspective view at the normal time of the lock mechanism provided in the headrest device by the present invention. Example 1 It is a perspective view when the vehicle of the lock mechanism provided in the headrest device by the present invention is collided. Example 1 It is side surface sectional drawing of the locking mechanism of FIG. (A) shows a cross-sectional view of a state where the stopper bracket restrains the lock pin in a normal state, and (B) shows a cross-sectional view of a state where the lock pin restrains the stopper bracket when a rear end collision occurs. Example 1 It is the side view which showed the structure of the conventional headrest apparatus typically.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Base bracket 2 Lock pin 3 Stopper bracket 4 Strap 5 Long hole 6 Tension spring 7 Lateral connecting rod 8 Lifting member 9 Step part 10 Side part 11 Column holder 12 Tilt shaft 13 Through-hole 21 Seat back frame 31 Headrest frame 32 Pressure receiving plate 33 Prop 34 Cantilever 35 Forward tilt restraint part 36 Headrest 37a, 37b Tilt shaft mounting member 38 Abutment part 39 Tilt spring 50 Lock mechanism 70 Headrest device M Seated person

Claims (1)

A headrest frame attached to the inner side of the seat back frame is provided with a pressure receiving plate for receiving a rear load applied to a seated person when the headrest is connected to the upper part and a tilting spring for tilting the headrest backward. In the provided headrest device,
A base bracket attached to the upper part of the seat back frame and having a long hole extending vertically on both sides;
A lock pin movably mounted in the elongated hole;
It is attached to the upper part of the headrest frame, and normally it abuts against the lock pin to restrain the downward movement of the lock pin, and when it is bumped, the pressure receiving plate moves backward and the headrest frame tilts forward. The stopper pin is released from the restraint of the lock pin, abuts on the lock pin that has been moved downward, and the stopper bracket that restrains the movement to the normal position by the lock pin;
One end is connected to the lock pin, the other end is connected to the lower end of the stopper bracket through the through hole of the stopper bracket, and a tension spring that urges the lock pin toward the stopper bracket;
A lock mechanism for a headrest device, comprising: a strap for returning the lock pin to a normal position.

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