JP3410224B2 - Seat reclining device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a seat reclining device which is attached to a seat device such as a vehicle and which adjusts an inclination angle of a seat back with respect to a seat cushion.

[0002]

2. Description of the Related Art In a seat reclining device disclosed in Japanese Utility Model Publication No. 42-7950, a sector gear is fixed to a seat back, while a sector gear and a worm gear that can be inserted into and removed from the seat cushion are rotatably attached to a seat cushion. There is. The worm gear is connected to the operating shaft, and the engagement of the worm gear with the sector gear is released by pulling the operating shaft in the axial direction and further lifting it. When a load is applied to the seat back in this state, the seat back tilts and the tilt angle can be changed quickly.When the hand is released from the operating shaft, the worm gear meshes again with the sector gear, and the seat back Held in position. In addition, when fine adjustment of the seat back inclination angle is required, rotating the operating shaft to rotate the worm gear causes the sector gear that meshes with the worm gear to gradually rotate, allowing the seat back to be steplessly adjusted to an arbitrary inclination angle. Can be changed to

In the seat reclining device disclosed in Japanese Patent Publication No. 52-9892, a worm wheel is fixed to a seat cushion while a worm gear is rotatably attached to a seat back and meshed with the worm wheel. In the axial direction of the worm gear, a groove having a width that allows the end edge of the worm wheel to be loosely fitted is engraved.When the handle connected to the worm gear is rotated, the end edge of the worm wheel can be fitted into the groove. The mesh between the worm gear and the worm wheel is released, and the seat back can be quickly tilted to any position. When the hand is released from the handle after the inclination angle of the seat back is changed, the worm gear is rotated by 90 degrees by the spring and meshes with the worm wheel again to be in the locked state. By gradually rotating the handle, the worm gear integrally rotates, and the worm wheel meshing with the worm gear also gradually rotates, so that the inclination angle of the seat back can be finely adjusted.

The seat reclining device disclosed in US Pat. No. 4,685,735 is a seat back bracket pivotally mounted on a seat mount, and a sector gear fixed to the seat back bracket and having spur teeth.
It is provided with a worm gear that is rotatably attached to the seat mount and meshes with the sector gear. The worm gear that meshes with the spur teeth of the sector gear is tilted relative to the sector gear by an angle corresponding to the spiral angle of the worm gear.By rotating the knob connected to the worm gear, the tilt angle of the seat back is adjusted appropriately. Has become.

Further, a sector gear is fixed to the seat back frame, and a lock gear that meshes with the sector gear is provided.
By manually releasing the engagement of the sector gear and the lock gear, the inclination angle of the seat back is adjusted appropriately.
Seat reclining devices are also known.

Further, a Taumel type seat reclining device utilizing the meshing of an external gear and an internal gear is well known.

[0007]

In the seat reclining device disclosed in Japanese Utility Model Publication No. 42-7950 or Japanese Patent Publication No. 52-9892, a worm gear and a sector gear or By releasing the mesh with the worm wheel,
Although it is a configuration that can change the inclination angle of the seat back quickly, in any of the configurations, the seat back is always biased to the upright position by the spring. However, there is a problem that it gives an uncomfortable feeling to a seated occupant.

Further, in the structure in which the rotation of the sector gear fixed to the seat back is locked by the lock gear, in addition to the above problems, the teeth formed on the sector gear and the lock gear are formed at a predetermined pitch, There was a problem that the back could not be finely adjusted.

Further, in the one disclosed in US Pat. No. 4,685,735 and the Taumel type seat reclining device, the sector gear and the worm gear or the external gear and the internal gear are always meshed with each other. However, there is a problem in that the inclination angle of the seat back cannot be changed quickly, and it takes time to change the inclination angle.

The present invention has been made in view of the above problems of the prior art, and the inclination angle of the seat back can be adjusted quickly and steplessly, and the seat back can be adjusted quickly when adjusting the inclination angle. It is an object of the present invention to provide a seat reclining device that does not move forward.

[0011]

In order to achieve the above object, a seat reclining device of the present invention includes a seat cushion having a built-in seat cushion frame and a seat back frame which is tiltably attached to the seat cushion. In the seat device including the seat back, the sector gear fixed to the seat back frame, the biasing means for biasing the seat back frame toward the front of the seat, and the sector gear that is constantly meshed with the sector gear and rotated to the seat cushion frame. The worm gear is movably mounted and has a lead angle equal to or larger than the friction angle with the sector gear, and braking means that frictionally engages with the worm gear to prevent rotation of the worm gear. While releasing the braking,
The worm gear is rotated via the sector gear by tilting the seat back, and the inclination angle of the seat back can be appropriately changed.

The braking means is composed of a braking member pivotally attached to the seat cushion frame, and a braking surface is formed on the braking member, while a braking surface is formed on a part of the worm gear. It is effective to prevent the worm gear from rotating by frictionally engaging the braked surface with the braking surface.

The braking means comprises a braking piece slidably attached to the seat cushion frame,
The rotation of the worm gear can be prevented by frictionally engaging the braking piece with the tooth surface of the worm gear.

[0014]

Since the lead angle of the worm gear is set to be equal to or larger than the friction angle with the sector gear, if the braking of the worm gear of the braking means is released, the worm gear rotates through the sector gear by the urging force of the urging means, and the seat back gradually moves. Tilt forward to the seat. In addition, the seat back is tilted rearward of the seat by applying a load to the seat back with the upper body of the occupant.

If the braking means is composed of a braking member pivotally attached to the seat cushion frame, and the braking surface and the braking surface are formed in a part of the braking member and the worm gear, the friction between the braking surface and the braking surface is generated. The engagement can prevent the worm gear from rotating, and can change the inclination angle of the seat back steplessly to hold it at an arbitrary position.

Even if the braking means is constituted by a braking piece slidably attached to the seat cushion frame and the rotation of the worm gear is blocked by frictional engagement with the tooth surface of the worm gear of the braking piece, the same as above. The action is obtained.

[0017]

Embodiments of the present invention will be described below with reference to the drawings. Generally, a seat device to which the seat reclining device of the present invention is applied is generally composed of a seat cushion and a seat back that is tiltably attached to the seat cushion, and the seat cushion and the seat back respectively include a seat cushion frame and a seat back. The frame is housed.

As shown in FIG. 1, of the sector gear 2 and the worm gear 4 that constantly mesh with each other, the sector gear 2
Is a bracket 4 fixed to the seat back frame 40
On the other hand, the worm gear 4 is rotatably attached to a bracket 6 which is screwed to a seat cushion frame (not shown) via a pair of centering bearings 8 while being screwed onto the seat cushion frame 2. One pin 10 is planted in the bracket 6, and the sector gear 2 is rotatably attached to the bracket 6 via the pin 10. A coil spring 12 is wound around the pin 10, and both ends of the coil spring 12 are locked to the pin 10 and the sector gear 2, respectively, and the seat back frame 40 is seated forward (direction A).
Always urged.

Further, as shown in FIG. 2, one end of the worm gear 4 is formed in a tapered shape to form a braked surface 4a which makes frictional contact with a tapered braking surface 14a formed inside the braking member 14. There is. One end 14b of the braking member 14 is pivotally attached to the bracket 6, while the other end 14c is biased in the direction of arrow B by a spring (not shown) and is constantly pressed by the cam 16. The cam 16 is integrally fixed to one end of a lever 18 and is swingably attached to the bracket 6 via a pin 20. An operation knob 22 is attached to the other end of the lever 18, and the cam 16 is swung by the vertical movement of the operation knob 22.
The lever 18 is constantly urged downward by a spring 24 and is held at a predetermined position.

FIG. 3 shows the engagement state between the braking surface 14a of the braking member 14 and the braking surface 4a formed on the worm gear 4. In the figure, the alternate long and short dash line indicates a normal time when the operation knob 22 is not operated, and in such a state, the braking surface 14a of the braking member 14 pressed by the cam 16 is frictionally engaged with the braked surface 4a of the worm gear 4. Therefore, the worm gear 4 is prevented from rotating. On the other hand, operation knob 2
When 2 is lifted upward, the cam 16 rotates counterclockwise in the figure, and the braking member 14 moves in the direction of arrow B by the urging force of the spring, and the braking surface 14 of the braking member 14 is moved.
The frictional engagement between a and the braked surface 4a of the worm gear 4 is released, and the worm gear 4 is in a state in which it can freely rotate (a state indicated by a chain double-dashed line).

Here, the lead angle of the worm gear 4 meshing with the sector gear 2 is set to be equal to or larger than the friction angle with the sector gear 2, and the friction surface between the braking surface 14a of the braking member 14 and the braking surface 4a of the worm gear 4 is set. In the state where the engagement is released, the seat back frame 40 easily tilts in the forward tilt direction (direction A in FIG. 1) by the urging force of the coil spring 12, while a rear load is applied to the seat back frame 40, Tilt in the opposite direction. That is, the sector gear 2
The worm gear 4 is rotated by the tilting of the.

The operation of the seat reclining device thus constructed will be described. In a normal state where the operation knob 22 is not operated, the braking surface 1 of the braking member 14 is pressed by the pressing force of the cam 16.
4a frictionally engages the braked surface 4a of the worm gear 4 to prevent the worm gear 4 from rotating. In such a state, the seat back frame 40 does not tilt forward due to the urging force of the coil spring 12, and conversely, even if a rear load is applied to the seat back frame 40, it does not tilt in the direction of the load. Absent.

On the other hand, when it is desired to change the inclination angle of the seat back, when the operation knob 22 is lifted, the cam 16 rotates counterclockwise in the figure. As a result, the braking member 14 moves in the direction of arrow B by the urging force of the spring, and the braking member 14
The frictional engagement between the braking surface 14a of 4 and the braking surface 4a of the worm gear 4 is released. When the seat back wants to lean forward, when the seated occupant takes a forward leaning posture, the worm gear 4 gradually rotates through the sector gear 2 by the biasing force of the coil spring 12, and the seat back becomes smooth. Tilt forward. When the operation knob 22 is released at a desired position, the cam 16 rotates clockwise in the drawing by the urging force of the spring 24, and the braking surface 14a of the braking member 14 and the braking surface 4a of the worm gear 4 are frictionally engaged again. As a result, the rotation of the worm gear 4 is blocked, so that the inclination angle of the seat back is maintained.

On the contrary, when the seat back is to be tilted backward, a load is applied to the seat back with the operation knob 22 raised, and the worm gear 4 resists the urging force of the coil spring 12. The seat back rotates in a direction opposite to that when tilted forward, and as a result, the sector gear 2 also rotates, so that the seat back gradually tilts rearward. When the hand is released from the operation knob 22 at a desired position, the braking surface 14a of the braking member 14 and the braked surface 4a of the worm gear 4 again frictionally engage with each other, and the rotation of the worm gear 4 is blocked. The inclination angle of is maintained.

FIG. 4 shows a second embodiment of the seat reclining device of the present invention. In the seat reclining device of this figure, the rotation of the worm gear 4 is blocked by pressing the substantially rectangular braking piece 26 against the tooth surface of the worm gear 4 with the cam 16. Therefore, the braking piece 26
Is a pair of braking piece holders 28 screwed to the bracket 6.
Thus, the worm gear 4 is held slidably in a direction substantially perpendicular to the axis of the worm gear 4, and is constantly urged toward the pressing surface of the cam 16 by urging means (not shown) such as a spring.

In the device of FIG. 1, the braking member 14
The braking surface 14a of the worm gear 4 is frictionally engaged with the braking surface 4a of the worm gear 4 to prevent the worm gear 4 from rotating. However, in the apparatus of FIG. 4, the braking piece 26 slidably attached to the bracket 6 is used. Is pressed against the tooth surface of the worm gear 4 to prevent the worm gear 4 from rotating. Except for this point, the other structure is the same, and therefore its description is omitted.

FIG. 5 shows a third embodiment of the seat reclining device of the present invention. The seat reclining device shown in this figure includes an operation lever 30 that can be operated in the axial direction, an operation lever holder 32 that is erected on the bracket 6 and holds the operation lever 30 slidably in the axial direction, and an operation lever 30. A pressing piece 34 fixed to the tip and a guide member 36 fixed to the bracket 6 and guiding the pressing piece 34 are provided. The braking piece 26 is interposed between the worm gear 4 and the pressing piece 34, and is constantly urged toward the pressing surface of the pressing piece 34 by an urging means (not shown) such as a spring. The sliding surfaces of the braking piece 26 and the pressing piece 34 are formed in a tapered shape, and when the operating lever 30 is operated, the pressing piece 34 slides along the guide member 34 integrally with the operating lever 30, while the pressing piece 34 is pressed. The braking piece 26 slides in a direction substantially perpendicular to the sliding direction of the piece 34, and the worm gear 4
The frictional engagement with the tooth surface of the worm gear 4 prevents the worm gear 4 from rotating.

Further, the operating lever holder 32 and the pressing piece 34
A spring 38 is interposed around the operation lever 30 between the two, and the pressing piece 34 is constantly urged to the left side in the drawing.

In the seat reclining device shown in FIG. 4, the operation knob 22 is lifted to release the frictional engagement between the braking piece 26 and the worm gear 4. However, in the seat reclining device shown in FIG. By pulling the operating lever 30 in the axial direction, the braking piece 2
The frictional engagement between the worm gear 4 and the worm gear 4 is released. Except for this point, the other configuration is the same, and the description thereof is omitted.

[0030]

Since the present invention is constructed as described above, it has the following effects.

Since the lead angle of the worm gear is set to be equal to or larger than the friction angle with the sector gear, if the braking of the worm gear by the braking means is released, the urging force of the urging means or a backward load is applied to the seat back. As a result, the seat back gradually tilts forward or backward.
At the time of tilting, the tooth surface friction between the sector gear and the worm gear acts as a damper, so that the seat back is tilted smoothly.

If the braking means is composed of a braking member pivotally attached to the seat cushion frame or a braking piece slidably attached to the seat cushion frame, frictional engagement of the braking member or the braking piece with the worm gear is achieved. As a result, the rotation of the worm gear can be prevented, and the inclination angle of the seat back can be continuously changed and held at an arbitrary position.

Further, since the worm gear and the sector gear are always meshed with each other, there is little play.

[Brief description of drawings]

FIG. 1 is a perspective view showing a first embodiment of a seat reclining device according to the present invention.

2 is a cross-sectional view taken along the line II-II in FIG.

FIG. 3 is a schematic cross-sectional view showing an operation of a braking member provided in the seat reclining device of FIG.

FIG. 4 is a perspective view showing a second embodiment of the seat reclining device according to the present invention.

FIG. 5 is a perspective view showing a third embodiment of the seat reclining device according to the present invention.

[Explanation of symbols]

2 sector gear 4 Worm gear 4a braking surface 6 bracket 8 Aligning bearing 12 springs 14 Braking member 14a Braking surface 16 cams 26 Braking piece

─────────────────────────────────────────────────── ─── Continuation of the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) A47C 1/02-1/16

Claims (3)

(57) [Claims] 1. A seat gear including a seat cushion including a seat cushion frame and a seat back tiltably attached to the seat cushion and including a seat back frame, comprising: a sector gear fixed to the seat back frame. When,
An urging means for urging the seat back frame toward the front of the seat, a worm gear which is constantly meshed with the sector gear and is rotatably attached to the seat cushion frame, and which has a lead angle equal to or greater than a friction angle with the sector gear. A braking means for frictionally engaging the worm gear to prevent rotation of the worm gear, releasing the braking of the worm gear by the braking means, and tilting the seat back to move the worm gear through the sector gear. A seat reclining device, which is configured to be rotated so that an inclination angle of the seat back can be appropriately changed. 2. The braking means comprises a braking member pivotally attached to the seat cushion frame, and a braking surface is formed on the braking member, while a braking surface is formed on a part of the worm gear. The rotation of the worm gear is prevented by frictional engagement between the braking surface and the braked surface.
The seat reclining device described in. 3. The braking means comprises a braking piece slidably attached to the seat cushion frame, and frictional engagement of the braking piece with a tooth surface of the worm gear prevents rotation of the worm gear. The seat reclining device according to Item 1.