JPH09286264A - 2-stage folding hinge structure for vehicle seats - Google Patents

Abstract

(57) [Abstract] [PROBLEMS] To improve a two-stage folding hinge structure of a vehicle seat so that a seat back in a forward-folded state can be stably used as a table. A reclining device (2) is provided on a seat cushion (S1), a hinge shaft (4) serving as a rotation center of a bracket (5) fixed to a seat back (S2) is provided at an upper end of an upper arm (3) of the reclining device, and the upper arm (3) is provided. By engaging the lock plate 7 provided on the bracket 5 with the first lock pin 6,
The seat back S2 is attached to the upper arm 3 and the bracket 5.
And the upper arm 3 is disengaged from the lock plate 7 and the first lock pin 6, and when the seat back S2 is tilted around the hinge shaft 4 as the center of rotation, the lock plate 7 is moved forward. A structure in which a second lock pin 8 different from the first lock pin 6 is provided at a position corresponding to, and the lock plate 7 is engaged with the second lock pin 8 to lock the seat back S2 in the forward tilted state. And

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a two-stage folding hinge structure for connecting a seat back and a seat cushion of a vehicle seat.

[0002]

2. Description of the Related Art Conventionally, as a vehicle seat to be installed in a rear compartment of a wagon type vehicle or the like, a seat cushion and a seat back are connected via a two-stage folding hinge so that the seat back can be reclining backward. There is a seat cushion that can be folded forward so that it can be stacked horizontally, and can be used as a table with the seat back folded forward.

As a two-stage folding hinge used for this type of seat, a bracket fixed to the side surface of the seat back is rotatable by a hinge shaft at the upper end of an upper arm of a reclining device provided at the rear end of the side surface of a seat cushion of the seat. There is a structure in which a lock pin is provided so as to be axially supported, and a lock pin is projectingly provided on the upper arm, and on the other hand, there is a bracket in which a lock plate urged by an urging means in a direction of engagement with the lock pin is rotatably provided. Then, normally, the lock plate engages with the lock pin to enable the seatback to be held and reclined in the upright posture by integrally forming the upper arm and the bracket, and the engagement between the lock plate and the lock pin is released to release the seatback from the above. The structure is such that it can be tilted forward to a nearly horizontal position where it overlaps with the seat cushion around the hinge axis. There is also one in which the above-mentioned lock plate is provided on the upper arm and the above-mentioned lock pin is provided on the bracket (Japanese Utility Model Publication No. 7-31466).

[0004]

However, in the above-mentioned conventional structure, although the seat back which is tilted forward is supported by the seat cushion, the seat back swings up and down relative to the seat cushion when the vehicle vibrates. There was a risk that the objects placed on it would fall. Therefore, an object of the present invention is to provide a two-stage folding hinge structure having a simple structure and having a lock mechanism for locking the seat back in a forward tilted state.

[0005]

According to the present invention, a reclining device is provided on a seat cushion, a hinge shaft serving as a pivot center of a bracket fixed to a seat back is provided on an upper end of an upper arm of the reclining device, and the reclining device is provided on the upper arm. By engaging the lock plate provided on the bracket with the first lock pin, the seat back can be reclined integrally with the upper arm and the bracket, and the upper arm can be engaged with the lock plate and the first lock pin. When the seat back is tilted with the hinge shaft as the center of rotation and the seat back is tilted forward, a second lock pin different from the first lock pin is provided at a position corresponding to the lock plate, and the second lock pin has the above-mentioned structure. The structure is such that the lock plate is engaged (Claim 1).

Further, according to the present invention, the bracket is provided with a projection portion which engages with the first lock pin when the seat back is tilted forward and also restricts downward rotation of the seat back (claim 2).

According to the present invention, only by attaching the second lock pin to the conventional structure, it is possible to prevent the rocking of the seat back when the seat back is tilted forward. Further, by providing the above-mentioned protrusion, it is possible to obtain a further excellent rocking prevention effect.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a vehicle seat to which the present invention is applied. A seat S has a seat back S2 divided left and right into a seat cushion S1 that covers almost the entire width of the passenger compartment. It has a structure in which the hinges H are used for connection. The two-stage folding hinges H having the same structure are provided at the lower ends of the left and right side surfaces of each seat back S2 (the figure shows one of them), and each seat back S2 can be reclined and tilted forward independently. A tray T is provided on the back surface of each seat back S2, and the seat back S2 is tilted forward so that it can be used as a table. H1, H in the figure
Reference numeral 2 is a cover member of a two-stage bent hinge H.

The two-stage folding hinge H will be described below with reference to FIGS. 2, 3 and 4. FIG. 2 is an exploded perspective view of the two-stage folding hinge H, and FIG. 3 is a two-stage folding hinge H.
FIG. 4 is a side view showing a state in which the seat back S2 is locked in the upright position and the forward tilt position, and FIG. 4 is a side view showing a state in which the seat back S2 is unlocked in the upright position and the front tilt position.

As shown in FIGS. 2, 3 and 4, the reclining device 2 is provided at the rear end of the side surface of the seat cushion S1.
Is provided. The reclining device 2 is provided with an operation handle 21 that extends toward the front. By operating the operation handle 21, the arm 31 and the arm 32 are provided.
The upper arm 3 is fixed by swaging with the studs and extended upward, and the upper arm 3 is reclined around the support shaft 1 with respect to the lower arm 22 fixed to the seat cushion S1.

A hinge shaft 4 is provided at the upper end of the upper arm 3 so that the lower end of the bracket 5 is rotatably supported. On the other hand, the upper end of the bracket 5 is bolted and fixed to the side surface of the seat back S2.

A first lock pin 6 is provided at a rear portion of the upper end of the upper arm 3 so that the rear end of the bracket 5 comes into contact with the bracket 5 when the bracket 5 linearly stands upright with respect to the upper arm 3. , The rearward position of rotation of the bracket 5 is restricted by the first lock pin 6. A recess 51 is formed at the rear end of the bracket 5 at a position where the first lock pin 6 abuts.

A lock plate 7 which is engageable with the first lock pin 6 when the bracket 5 is in the upright posture is rotatably provided substantially in the center of the bracket 5. The base end of the lock plate 7 is sandwiched between the bracket 5 and the reinforcement 52, and the operation shaft 72 and the stay 73 are supported by the support shaft 71.
Is rotatably supported integrally with. Lock plate 7
Has an engaging groove 74 formed at the tip thereof so that the first lock pin 6 can be engaged with the engaging groove 74. The urging force of a spring 75 bridged between the stay 73 and the upper end of the bracket 5 causes the first Is urged in the engagement direction with the lock pin 6. The lock plate 7 has its rotation range in the bracket 5
When the bracket 5 is in the upright posture, the lock plate 7 is engaged with the first lock pin 6 at the position where the stopper 53 is rotationally restricted, and the upper arm 6 is restricted by the stopper 53. 3 and the bracket 5 are locked together.

Further, at the upper front part of the upper arm 3, when the seat back S2 is tilted forward by rotating the bracket 5 around the hinge shaft 4, the lock plate 7 is moved.
Of the first lock pin 6 at a position corresponding to the engaging groove 74 of
A second lock pin 8 different from the above is projectingly provided. The second lock pin 8 has a diameter smaller than that of the first lock pin 6 and projects toward the bracket 5, and has a length that does not hinder the rotation of the bracket 5. The second lock pin 8 contacts the side 741 of the engagement groove 74 of the lock plate 7 on the side of the support shaft 71 when the seat back S2 is tilted forward. The side 741 has a shape of an arc centered on a point displaced upward from the support shaft 71, which is the rotation center of the lock plate 7, and the distance between the support shaft 71 and the side 741 is The length of the engaging groove 74 gradually increases from the inlet side to the deepest part.

At the lower end of the bracket 5, a seat back S
A protrusion 55 is formed on the first lock pin 6 to abut against the first lock pin 6 from the lower side when the latter is tilted forward, and the abutment surface is concave.

Next, the operation of the seat S will be described. Normally,
As shown in FIG. 3A, the upper arm 3 and the bracket 5 are linear, and the first lock pin 6 of the upper arm 3 is formed.
Comes into contact with the concave portion 51 of the bracket 5, and the lock plate 7 of the bracket 5 is engaged with the first lock pin 6 by the urging force of the spring 75 to keep the seatback S2 in the upright posture. The operating handle 21 is operated to recline the seat back S2 with the upper arm 3 and the bracket 5 integrally around the support shaft 1.

To bring the seat back S2 forward, use FIG.
As shown in (A), the operating lever 72 is operated to rotate the lock plate 7 in a direction against the urging force of the spring 75 to release the engagement between the first lock pin 6 and the lock plate 7. . Then, as shown in FIG. 4B, the seat back S2 is tilted forward about the hinge shaft 4 and rotated to bring the protrusion 55 of the bracket 5 into contact with the first lock pin 6. As a result, the seat back S2
Are positioned and supported substantially horizontally along the upper surface of the seat cushion S1. At this time, the second lock pin 8 of the upper arm 3 is located near the side edge of the root of the lock plate 7, and as shown in FIG. Accordingly, the lock plate 7 enters the engaging groove 74 and comes into contact with the side edge 741 of the engaging groove 74. In this case, as the return rotation of the lock plate 7 progresses and the second lock pin 8 approaches the deepest part of the engagement groove 74, the side edge 741 becomes closer to the lock plate 7.
Since it deviates from the rotation orbit line to the outside, the contact pressure between the side edge 741 and the second lock pin 8 is increased, and the seat cushion S2 is reliably locked in the forwardly tilted state. In this state, the seat back S2 is used as a table.

According to the above-described embodiment, when the seat back S2 is tilted forward, the second lock pin 8 of the upper arm 3 and the side edge 741 of the lock plate 74 are engaged with each other. Since the upward rotation is prevented and the protrusion 55 of the bracket 5 is in contact with the first lock pin 6 at the rear of the upper arm 3 from below, the downward rotation of the seat back S2 is prevented. Therefore, the seat back S2 can be held in a constant horizontal state even when the vibration of the vehicle acts.

The second lock pin 8 of the upper arm 3 is
The first lock pin 6 on the rear side has substantially the same diameter as that of the first lock pin 6 and is installed at a position slightly higher than the above. You may do it.

Without providing the protrusion 55 on the upper arm 3,
The seat back S2 may be supported by the seat cushion S1 in a state where the seat back S2 is tilted forward. However, in terms of strengthening the lock of the seat back S2, the protrusion 55 is provided to engage with the first lock pin 6. desirable.

Further, according to the present invention, also in a two-stage folding hinge having a structure in which the first lock pin is provided on the bracket side and the lock plate is provided on the upper arm side, the seat back is in a position corresponding to the lock plate when the seat back is tilted forward. A second lock pin may be provided, and these may be engaged with each other to hold the seat back in a forwardly tilted state.

[0022]

According to the present invention, the seat back that has been tilted forward can be locked in a horizontal state only by attaching one lock pin to the conventional two-stage folding hinge structure, and the seat back can be used as a table. The stability can be improved.

[Brief description of drawings]

FIG. 1 is a perspective view of a vehicle seat provided with a two-stage folding hinge structure of the present invention.

FIG. 2 is an exploded perspective view of a two-stage folding hinge structure of the present invention.

FIG. 3 (A) is a side view showing a state in which a seat back having a two-stage folding hinge structure of the present invention is locked in a standing posture,
FIG. 3B is a side view showing a state in which the seat back is tilted forward and locked in the posture.

FIG. 4 (A) is a side view showing a state in which a seat back having a two-stage folding hinge structure of the present invention is unlocked in a standing posture, and FIG. 4 (B) is unlocked in a posture in which the seat back is tilted forward. It is a side view which shows the state which was done.

[Explanation of symbols]

 S1 Seat cushion S2 Seat back 1 Spindle 2 Reclining device 3 Upper arm 4 Hinge shaft 5 Bracket 55 Protrusion 6 First lock pin 7 Lock plate 8 Second lock pin

Claims (2)

[Claims] 1. A bracket fixed to a seat back is rotatably supported by a hinge shaft on an upper end of an upper arm of a reclining device provided on a seat cushion, and a first lock pin is projectingly provided on the upper arm. At the same time, the bracket is provided with a lock plate that can be engaged with and disengaged from the first lock pin and is urged in a direction of engagement with the first lock pin by urging means. The seat back can be reclined by engaging the lock pin with the upper arm and the bracket as one body, and the seat plate is moved forward to a substantially horizontal position about the hinge axis by releasing the engagement between the lock plate and the first lock pin. In the possible two-stage folding hinge structure of the vehicle seat, the upper arm includes
A second stage of a vehicle seat characterized in that when the seat back is tilted to a substantially horizontal position, the lock plate engages and a second lock pin that restricts the upward rotation of the seat back is provided in a protruding manner. Foldable hinge structure. 2. The bracket is provided with a projection portion that engages with the first lock pin and restricts downward rotation of the seat back when the seat back is tilted to a substantially horizontal position. Item 2. A two-stage folding hinge structure for a vehicle seat according to Item 1.