JP7417050B2 - reclining device - Google Patents

Description

The present invention relates to a seat reclining device that tiltably holds a seat back relative to a seat cushion.

2. Description of the Related Art Conventionally, a reclining device disclosed in Patent Document 1 below is known as a seat reclining device that tiltably holds a seat back relative to a seat cushion. This reclining device is configured such that the external teeth of the external gear welded to the lower arm and the internal teeth of the internal gear welded to the upper arm coaxially and rotatably fit together. Further, by moving a pair of eccentric cams that eccentrically move the external gear and the internal gear, rotation of the external gear and the internal gear is restricted and rotation is allowed. The structure is such that a pair of eccentric cams are pushed apart by a spring to remove play between the external gear and internal gear and maintain the amount of eccentricity.

Japanese Patent Application Publication No. 2011-207253

By the way, in the above-mentioned structure of the reclining device, which is desired to be miniaturized, when a large force is applied such as during a car collision, the eccentric cam comes off and the amount of eccentricity between the external gear and the internal gear decreases. The meshing between the external gear and the internal gear becomes shallow, and the holding load of the gear decreases. That is, in order to maintain the angle of the seat back even when a large force is applied, it is necessary not to make the engagement shallow.

The present invention has been made to solve the above-mentioned problems, and its purpose is to provide a reclining device that can realize miniaturization and thinning of internal gears and external gears. .

In order to achieve the above object, a reclining device according to a first aspect of the present invention holds a seat back so as to be tiltable relative to a seat cushion. A first frame fixed to either one of the seat cushion and the seat back, a second frame fixed to the other of the seat cushion and the seat back, and a second frame connected to the first frame and having external teeth on the outer peripheral surface. an externally toothed gear having an externally toothed boss portion coaxial with the axial direction on the inner circumferential surface thereof, and an internal tooth connected to the second frame and capable of meshing with the external teeth on the outer circumferential surface; an internal gear that is coaxially and rotatably fitted to the external gear or the internal gear, and which is coaxially and rotatably fitted to the external gear or the internal gear; A rotating shaft that revolves one gear shaft around the other gear shaft, and is inserted between the internally toothed boss portion and the externally toothed boss portion, and is inserted between the internal toothed boss portion side and the external toothed boss portion side at the same time. The rotation of the internal toothed boss part and the external toothed boss part is restricted by contact, and when the rotating shaft rotates, at least one of the internal toothed boss part side and the external toothed boss part side slides. a pair of wedge-shaped cams that allow rotation of the internally toothed boss and the externally toothed boss; and a pair of wedge-shaped cams that simultaneously contact the internally toothed boss and the externally toothed boss. A biasing spring member is provided. The invention also includes an eccentricity reduction prevention plate that is inserted between the internally toothed boss portion and the externally toothed boss portion to ensure a minute gap between the internally toothed boss portion side and the external toothed boss portion side. .
The eccentricity reduction prevention plate has a half-sleeve shape, and a first semicircular shape that is approximately equal to the inner periphery of the U-shaped bushing that is in contact with the outer periphery is provided on the outer periphery of the eccentricity reduction prevention plate. A second semicircular shape that is approximately equal to the outer circumference of the externally toothed boss portion that is in contact with the inner circumference is provided on the inner circumference side of the amount reduction prevention plate, and the thickness of the U-shaped bush is equal to the thickness of the eccentricity reduction prevention plate. The thickness is approximately equal to the sum of the thickness of the pair of wedge-shaped cams, the side surface of the eccentricity reduction prevention plate is in contact with the side surface of the pair of wedge-shaped cams, and the outer periphery of the pair of wedge-shaped cams is approximately equal to the sum of the thicknesses of the pair of wedge-shaped cams. Touches the inner circumference of the U-shaped bush.
Note that an eccentricity reduction prevention plate may be provided on the inner circumferential side of the U-shaped bushing, or an eccentricity reduction prevention plate may be provided on the outer circumference side of the U-shaped bushing.

In the invention of claim 1, it is inserted between the internal tooth boss portion and the external tooth boss portion, and the internal tooth boss portion and the external tooth boss portion are inserted while ensuring a minute gap between the internal tooth boss portion side and the external tooth boss portion side. Equipped with an eccentricity reduction prevention plate that makes the tooth boss part eccentric. When a large force is applied, the small gap disappears, and the eccentricity reduction prevention plate minimizes the decrease in eccentricity between the external gear and internal gear, thereby improving the connection between the external gear and internal gear. The meshing is hardly shallow and the holding load of the gear is maintained. Even if the external gear and internal gear are made smaller, the seatback angle can be maintained even when a large force is applied.
Therefore, the internal gear and the external gear can be made smaller and thinner, and the reclining device can be made smaller and thinner.

FIG. 1 is a side view conceptually showing an example of a vehicle seat equipped with a reclining device of the present invention. FIG. 2 is an exploded perspective view of the reclining device. 3(A) is a front view of the reclining device, FIG. 3(B) is a side view of the reclining device, and FIG. 3(C) is a DD cross-sectional view of the reclining device of FIG. 3(A). be. 4(A) is a sectional view taken along line EE of the reclining device shown in FIG. 3(A), and FIG. 4(B) is a sectional view taken along line BB of the reclining device shown in FIG. 3(B). FIG. 3B is a sectional view taken along the line CC of the reclining device shown in FIG. 3(B).

Hereinafter, one embodiment of a vehicle seat 10 equipped with a reclining device 20 according to the present invention will be described with reference to the drawings. FIG. 1 is a side view conceptually showing an example of a vehicle seat 10 equipped with a reclining device 20 of the present invention.
As shown in FIG. 1, a vehicle seat 10 equipped with a reclining device 20 of the present invention includes a seat cushion 11 that receives the seat of a seated person, and a seat cushion 11 that is tiltable with respect to the seat cushion 11 and that supports the back of the seated person. The seat back 12 is provided with a seat back 12 for receiving the seat.

A seat frame 11a serving as the skeleton of the seat cushion 11 and a back frame 12a serving as the skeleton of the seat back 12 are shown in FIG. 4(A) of the reclining device 20 installed at the end of the seat frame 11a. They are connected via a first frame 21, a second frame 22, and the like. The seat back 12 can be tilted relative to the seat cushion 11 in accordance with the rotational drive of a tilting motor (not shown) provided in the reclining device 20.

Next, the configuration of the reclining device 20 will be explained using FIGS. 2 to 5. FIG. 2 is an exploded perspective view of the reclining device. 3(A) is a front view of the reclining device, FIG. 3(B) is a side view of the reclining device, and FIG. 3(C) is a DD cross-sectional view of the reclining device of FIG. 3(A). be. 4(A) is a sectional view taken along line EE of the reclining device shown in FIG. 3(A), and FIG. 4(B) is a sectional view taken along line BB of the reclining device shown in FIG. 3(B). FIG. 5 is a sectional view taken along line CC of the reclining device shown in FIG. 3(B).

As shown in FIG. 2, the reclining device 20 includes, in addition to the frames 21 and 22 described above, an external gear 23, an internal gear 24, a rotating shaft 25, a plate cover 26, a resin bearing 27, a U-shaped bush 28, It includes an eccentricity reduction prevention plate 32, a pair of wedge-shaped cams 30A and 30B, a spring 29, and a shaft cover 31. In addition, in FIG. 3, description of both frames 21 and 22 is omitted for convenience of explanation.

The external gear 23 is formed in a substantially annular shape around the through hole 23b, and has external teeth 23a formed on its outer peripheral surface. As shown in FIG. 4(A), this external gear 23 is formed such that an external tooth boss portion 23c protrudes from the center of one side, and four approximately arc-shaped protrusions from the other side. 23d is formed to protrude.

As shown in FIGS. 2, 4(A), and 4(B), the internal gear 24 includes a cylindrical portion 24d in which internal teeth 24a are formed on the inner peripheral surface, and internal teeth centered around the through hole 24b. It includes a side plate portion 24e in which a boss portion 24c is formed. The internal teeth 24a are formed to have a larger number of teeth than the external teeth 23a so as to mesh eccentrically with the external teeth 23a. Specifically, for example, when the number of teeth of the external teeth 23a is set to 32, the number of teeth of the internal teeth 24a is set to 33.

Further, a portion on the side plate portion 24e side is formed so as not to mesh with the external teeth 23a when the external gear 23 and the internal gear 24 mesh. Further, the side plate portion 24e is provided with a half-arc-shaped engagement protrusion 24g for fixing the internal gear 24 to the second frame 22 via the shaft cover 31.

The rotating shaft 25 is coaxial with the externally toothed boss portion 23c of the external gear 23 and is formed to be rotatably fitted therein. This rotating shaft 25 is rotated at a predetermined reduction ratio according to the rotational drive of the tilting motor when the seat back 12 is tilted with respect to the seat cushion 11. Serrations 25a are formed to connect rotating members that rotate according to the rotational drive of the tilting motor.

The plate cover 26 is formed of a metal plate in a substantially cylindrical shape, and serves to restrict the axial movement of the external gear 23 whose external teeth 23a mesh with the internal teeth 24a. It is caulked and fixed to the end of the cylindrical portion 24d of 24.

A cylindrical resin bearing 27 with excellent wear resistance and a small coefficient of friction is fitted into the through hole 24b of the internal gear 24 in order to reduce the frictional force at the contact portion of the U-shaped bush 28 described below. Between the inner circumferential surface of the bearing 27 and the outer circumferential surface of the externally toothed boss portion 23c of the external gear 23, there is a groove as shown in FIG. A U-shaped bush 28 and a pair of wedge-shaped cams 30A and 30B are inserted into the holder. Further, in the BB cross section of FIG. 3(B), as shown in FIG. 4(B), the U-shaped bush 28 is inserted to ensure a small gap, and the eccentricity reduction prevention plate 32 is inserted.

The thickness T3 of the U-shaped bushing 28 shown in FIG. 2 is approximately equal to the sum of the thickness T1 of the U-shaped bushing 28 and the thickness T2 of the wedge-shaped cams 30A and 30B. The eccentricity reduction prevention plate 32 is inserted between the internal toothed boss portion 24c and the external toothed boss portion 23c, and is inserted between the U-shaped bush 28 in the resin bearing 27 on the internal toothed boss side and the external toothed boss portion 23c. The internal toothed boss portion 24c and the external toothed boss portion 23c are made eccentric by ensuring a minute gap, and are brought into contact with a pair of wedge-shaped cams 30A and 30B on one side 32s (see FIG. 2) of the eccentricity reduction prevention plate 32. . The eccentricity reduction prevention plate 32 has a half-sleeve shape, and a first semicircular shape that is approximately equal to the inner periphery 28I of the U-shaped bush 28 that is in contact with the outer periphery 32O is provided on the outer periphery 32O side of the eccentricity reduction prevention plate 32. On the inner periphery 32I side of the eccentricity reduction prevention plate 32, a second semicircular shape is provided which is approximately equal to the outer periphery of the externally toothed boss portion 23c that is in contact with the inner periphery 32I.

The U-shaped bush 28, the pair of wedge-shaped cams 30A and 30B, and the eccentricity reduction prevention plate 32 are arranged between the inner circumferential surface of the resin bearing 27 and the outer circumferential surface of the externally toothed boss portion 23c. The internal gear 24 is made eccentric with respect to the gear 23, and the internal teeth 24a are meshed with the external teeth 23a. When the rotating shaft 25 fitted into the through hole 23b of the external gear 23 rotates, the U-shaped bush 28, the pair of wedge-shaped cams 30A and 30B, and the eccentricity reduction prevention plate 32 are rotated, and the external gear 23a and By changing the meshing position of the internal teeth 24a, either the external gear 23 or the internal gear 24 can be caused to revolve around the other gear axis. Both engaging ends 29a of the spring 29 are engaged with the outer shapes of the wedge-shaped cams 30A and 30B, and unless a rotational force is input to the rotating shaft 25, the relative relationship between the rotating shaft 25 and the internal gear 24 is reduced. A spring 29 urges the wedge-shaped cams 30A and 30B in a direction that separates them so as to inhibit their movement.

Then, the shaft cover 31 formed in a substantially annular shape is assembled to the internal gear 24 so that the engagement protrusions 24g of the internal gear 24 are inserted through the three arc-shaped openings 31a. As a result, the rotating shaft 25, the U-shaped bush 28, etc. are held in proper positions, and dust and dirt are prevented from entering the meshing portions and the like.

Then, as shown in FIG. 4, the first frame 21 and each protrusion 23d of the external gear 23 are welded and fixed, and the second frame 22 and the engagement protrusion 24g of the internal gear 24 (see FIG. 2), etc. By welding and fixing these, the reclining device 20 is completed.

When the rotating shaft 25 rotates in response to the rotational drive of the tilting motor in order to tilt the seat back 12 with respect to the seat cushion 11, the restriction by the wedge-shaped cams 30A and 30B is released, and the rotating shaft 25 is rotated. According to the rotation, the external gear 23 and the internal gear 24 rotate relative to each other, and the seat back 12 tilts with respect to the seat cushion 11. By stopping the rotation of the rotating shaft 25, the rotation of the external gear 23 and the internal gear 24 is restricted by the wedge-shaped cams 30A and 30B.

The reclining device 20 of the embodiment secures a minute gap between the external toothed boss portion 23c and the U-shaped bush 28, contacts the internal toothed boss portion side and the external toothed boss portion side simultaneously, and presses the internal toothed boss portion. 24c and the externally toothed boss portion 23c are provided. Even when a large force is applied, the eccentricity reduction prevention plate 32 only slightly reduces the eccentricity between the external gear 23 and the internal gear 24. The engagement with the internal teeth 24a is only slightly shallower, and the holding load of the gear is maintained. Even if the external gear 23 and the internal gear 24 are made smaller and thinner, the angle of the seat back can be maintained even when a large force is applied.
Therefore, the internal gear and the external gear can be made smaller and thinner, and the reclining device can be made smaller and thinner.

In the reclining device 20 of the embodiment, the wedge-shaped cams 30A and 30B are urged in a direction away from each other by the spring 29, thereby removing play between the gears. By providing the eccentricity decrease prevention plate 32, even when a large force is applied to the reclining device, the decrease in the eccentricity of the external gear 23 and the internal gear 24 can be minimized. That is, even when a large force is applied to the external gear 23 and the internal gear 24, the meshing between the external teeth 23a of the external gear 23 and the internal teeth 24a of the internal gear 24 only becomes slightly shallow, and the load is reduced. Possible to retain.
Note that it is also possible to integrate the U-shaped bush and the eccentricity reduction prevention plate.
Furthermore, an eccentricity reduction prevention plate may be provided on the inner circumferential side of the U-shaped bushing, or an eccentricity reduction prevention plate may be provided on the outer circumference side of the U-shaped bushing.
Further, it is also possible to provide an eccentricity reduction prevention plate that secures a small gap between the inner circumferential surface of the resin bearing 27 and the outer circumferential side of the externally toothed boss portion 23c.

Here, the present invention is not limited to the above embodiment, and may be embodied as follows, and even in that case, the same effects and effects as the above embodiment can be obtained.
(1) The first frame 21 is not limited to being connected to the seat frame 11a and the second frame 22 is connected to the back frame 12a. 22 may be connected to the seat frame 11a.

(2) The first frame 21 and the second frame 22 may be part of the seat frame 11a and the back frame 12a.

10... Vehicle seat 11... Seat cushion 12... Seat back 20... Reclining device 21... First frame 22... Second frame 23... External gear 23a... External gear 24... Internal gear 24c... Internal gear 25... Rotating shaft 27 ...Resin bearing 28...U-shaped bush 29...Spring 30A...Wedge-shaped cam 30B...Wedge-shaped cam 32...Eccentricity reduction prevention plate

Claims (1)

A seat reclining device that tiltably holds a seat back relative to a seat cushion,
a first frame fixed to either the seat cushion or the seat back;
a second frame fixed to the other of the seat cushion and the seat back;
an external gear connected to the first frame, having external teeth formed on its outer circumferential surface, and having an externally toothed boss portion coaxial with the axial direction on its inner circumferential surface;
an internal gear connected to the second frame, having internal teeth formed on its outer circumferential surface that can mesh with the external teeth, and having an internal tooth boss portion coaxial with the axial direction on the inner circumferential surface;
a rotation shaft that coaxially and rotatably fits into the external gear or the internal gear, and causes either the external gear or the internal gear to revolve around the other gear shaft;
is inserted between the internal toothed boss portion and the external toothed boss portion, contacts the internal toothed boss portion side and the external toothed boss portion side simultaneously, and connects the internal toothed boss portion and the external toothed boss portion. and at the same time, when the rotating shaft rotates, at least one of the internally toothed boss section and the externally toothed boss section slides to allow rotation of the internally toothed boss section and the externally toothed boss section. a pair of wedge-shaped cams,
The internal tooth boss portion and the external tooth boss portion are interposed between the internal tooth boss portion and the external tooth boss portion, and are inserted between the internal tooth boss portion and the external tooth boss portion while ensuring a minute gap between the internal tooth boss portion side and the external tooth boss portion side. an eccentricity reduction prevention plate that eccentrically connects the boss part;
a spring member that urges the pair of wedge-shaped cams to simultaneously contact the internal toothed boss portion side and the external toothed boss portion side;
Equipped with
The eccentricity reduction prevention plate has a half sleeve shape,
A first semicircular shape that is approximately equal to the inner circumference of the U-shaped bush that is in contact with the outer circumference is provided on the outer circumference side of the eccentricity reduction prevention plate,
A second semicircular shape that is approximately equal to the outer circumference of the externally toothed boss portion that is in contact with the inner circumference is provided on the inner circumference side of the eccentricity reduction prevention plate,
The thickness of the U-shaped bush is approximately equal to the combined thickness of the eccentricity reduction prevention plate and the pair of wedge-shaped cams;
A side surface of the eccentricity reduction prevention plate contacts a side surface of the pair of wedge-shaped cams,
A reclining device characterized in that an outer periphery of the pair of wedge-shaped cams is in contact with an inner periphery of the U-shaped bush .

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