JPH10309963A - Seat sliding device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the enlargement of outer shape without increasing the number of part items by providing a rotating force switching mechanism arranged between a lead screw and a nut body and capable of changing the rotating force imparted to the lead screw by the movement of the nut body while a seat is retreated on the down side. SOLUTION: A rotating force switching mechanism 13 comprises first and third flanks 7b1, 8b1 forming pressure-side flanks when a seat is moved on down side in the male screws 7b, 8b of first and second lead screws 7, 8, and fifth and seventh flanks 11a1, 12a1 forming the pressure-side flanks when the seat is moved on down side in the female screws 11a, 12a of first and second nut bodies 11, 12. The rotating force switching mechanism 13 can be formed without enlarging the outer shapes of the first and second lead screws 7, 8 and the first and second nut bodies 11, 12, and also requires no additional part because it is not separately provided on a seat sliding device.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet slide device for automatically sliding a sheet.

[0002]

2. Description of the Related Art As a seat slide device for automatically sliding a seat, when a power supply in a forward direction is connected to a seat motor, an armature provided in the seat motor rotates forward to be supported by a lower rail. The lead screw rotates forward, and the nut body fixed to the seat together with the upper rail movably mounted on the lower rail and meshed with the lead screw moves toward the rear side of the vehicle body by the forward rotation of the lead screw. On the other hand, when a power supply in the opposite direction is connected to the seat motor, the armature provided in the seat motor rotates in the reverse direction, causing the lead screw to rotate in the reverse direction, and the nut body meshed with the lead screw to rotate in the opposite direction to the lead screw. By rotation, it moves with the seat toward the front side of the vehicle body.

[0003]

In the seat slide apparatus described above, a trapezoidal rolling screw is formed on the lead screw, and the lead screw is disposed to be inclined downward from the front to the rear of the vehicle body. Was. for that reason,
When the seat is moved from the front part to the rear part of the body, the load including the weight of the seat and the weight of the upper rail is applied as a negative load to the nut body, and the load is applied to the nut body by the negative load. The screw rotates forward at a rotation speed exceeding the rotation force of the seat motor,
As a result, a metallic rubbing noise may be generated from the lead screw and the nut body. Therefore, in order to eliminate such metallic rubbing noise, a device provided with braking means for preventing the lead screw from rotating beyond a predetermined number of rotations was considered. Because it was configured separately from the existing seat slide device, an increase in the number of components as the entire device was unavoidable, and when such a braking means was provided, the external shape of the entire seat slide device was large. Therefore, there is a problem that installation in a limited space such as a lower portion of the seat may be difficult.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a seat slide apparatus capable of braking a lead screw without increasing the number of parts and without increasing the outer shape.

[0005]

Configuration of the Invention

[0006]

According to a first aspect of the present invention, there is provided a seat slide apparatus comprising: a seat motor having an armature that rotates forward or backward depending on a direction of current supply;
A nut and a lead are arranged in the same direction as the moving direction of the sheet, mesh with the nut, and rotate forward or backward depending on the rotation direction of the armature of the sheet motor, thereby moving the sheet forward or downward. A rotational force that is arranged between the lead screw that moves backward and the lead screw and the nut body, and that can change the rotational force given to the lead screw by the movement of the nut body while the sheet moves backward to the down side A switching mechanism is provided.

In a seat slide device according to a second aspect of the present invention, a lower rail which is inclined downward from a horizontal plane from a front portion to a rear portion of the vehicle body and is fixed to the vehicle body side, and is movably mounted along the lower rail. The upper rail fixed to the seat, a seat motor having an armature that rotates forward by connecting the power supply in the forward direction and rotates in the reverse direction by connecting the power supply in the reverse direction, a nut body fixed to the upper rail, It has a lead screw that has a lead in the same direction as the moving direction and is meshed with the nut body and rotates forward or backward by the rotation of the armature of the seat motor, and the lead screw and the nut body have a seat at the front of the vehicle body. The flank angle of the pressure side flank when moving from Is characterized by small teeth than the corner has a structure which is formed respectively.

In the seat slide device according to a third aspect of the present invention, the lead screw is formed with a lead screw side tooth portion, and the nut body is formed with a nut body side tooth portion that can mesh with the lead screw side tooth portion. The lead screw side tooth portion and the nut body side tooth portion have a flank angle of the pressure side flank selected from 3 degrees to 9 degrees, and a flank angle of the play side flank selected from a range of 25 degrees to 33 degrees. It is characterized by having the configuration described above.

[0009]

In the seat slide device according to the first aspect of the present invention, when the seat is retreating downward, the rotating force switching mechanism disposed between the lead screw and the nut body moves the nut body. The rotation force applied to the lead screw is changed to a small value. Therefore, the rotational speed of the lead screw does not increase due to the force given to the nut body by the weight of the sheet, and the rotational force switching mechanism for preventing the rotational speed of the lead screw from increasing is increased. Because it is arranged between the two, the braking means does not require parts to be added to the lead screw and the nut body as compared with those separately configured, and the outer shape of the lead screw and the nut body changes. There is no.

[0010] In the seat slide device according to the second aspect of the present invention, when the seat is moving from the front part to the rear part of the vehicle body, the teeth of the lead screw and the nut body are shifted from the flank angle of the play-side flank. Because the flank angle of the pressure side flank is smaller, the force given to the lead screw from the nut body by the weight of the seat and the upper rail is greater in the lead screw lead direction, while the lead screw helical winding It takes less in the direction. Therefore, the rotation speed of the lead screw does not increase due to the force applied to the nut body, and the lead screw is braked by the teeth formed on the lead screw and the nut body. Therefore, as compared with a configuration in which the braking means is formed separately, there is no need for a component added to the lead screw and the nut body, and there is no change in the outer shapes of the lead screw and the nut body.

In the seat slide device according to a third aspect of the present invention, when the seat is moving from the front part to the rear part of the vehicle body, the teeth of the lead screw and the nut body have the flank angle of the pressure side flank. The flank angle of the play side flank is smaller than the flank angle of the play side flank because the flank angle of the play side flank is selected from the range of 25 degrees to 33 degrees. Therefore, the force given to the lead screw from the nut body by the weight of the seat and the upper rail is large in the lead direction of the lead screw side teeth of the lead screw, while the helical direction of the lead screw side teeth of the lead screw is large. It takes a little. Therefore,
The rotation speed of the lead screw is not increased by the force applied to the nut body, and the lead screw is formed by the flank angles of the lead screw side teeth formed on the lead screw and the nut body side teeth formed on the nut body. Is braked. Therefore, as compared with a configuration in which the braking means is formed separately, there is no need for a component added to the lead screw and the nut body, and there is no change in the outer shapes of the lead screw and the nut body.

[0012]

1 to 3 show one embodiment of a seat slide device according to the present invention.

The illustrated seat slide device 1 mainly includes a seat motor 2, a right lower rail 3, a left lower rail 4, a right upper rail 5, a left upper rail 6, a first lead screw (right) 7, a second , A right gear box 9, a left gear box 10, a first nut body 11 (right), a second nut body (left) 12, and a torque switching mechanism 13. .

The seat motor 2 is provided on the left gear box 1.
The armature 2b, which is mounted on the zero side and is accommodated in the motor case 2a, rotates forward by the connection of the power supply on the positive side, and reversely rotates by connection of the power supply on the opposite side. A cable 14 is coupled to the armature shaft 2b1 provided on the armature 2b at one end of the motor case 2a, and a first worm gear 15 described later in the right gear box 9 is connected via the cable 14.
Are combined. Also, the armature shaft 2b1
Is connected to a second worm gear 16 described later in the left gear box 10 at the other end of the motor case 2a.

The right lower rail 3 is attached to the vehicle body so as to be inclined downward from a horizontal plane 00 shown in FIG. 2 from the front to the rear of the vehicle. A right gear box 9 is fixed to one end of the right lower rail 3 on the front side of the vehicle body.

A right upper rail 5 is mounted on the right lower rail 3 so as to be movable along the length direction of the right lower rail 3. A seat (not shown) is fixed to the upper part of the right upper rail 5. I have.

The lower rail 4 on the left side is provided as a pair with the lower rail 3 on the right side. The lower rail 4 is attached to the vehicle body from the front to the rear of the vehicle body, inclining downward with respect to the horizontal plane 00 shown in FIG. I have. A left gear box 10 is fixed to one end of the left lower rail 4 on the front side of the vehicle body.

A left upper rail 6 is mounted on the left lower rail 4 so as to be movable along the length direction of the left lower rail 4. The left upper rail 6 is provided as a pair with the right upper rail 5, and a seat (not shown) is fixed to an upper portion of the left upper rail 6.

As shown in FIG. 2, a first worm gear 15 and a first helical gear 17 are rotatably housed in the right gear box 9, and the first worm gear 15 The helical gear 17 is engaged. One end of the first lead screw 7 is connected to the first helical gear 17.

As shown in FIG. 2, a second worm gear 16 and a second helical gear 18 are rotatably housed in the left gear box 10, respectively.
The second helical gear 18 is meshed with the worm gear 16. One end of the second lead screw 8 is connected to the second helical gear 18.

The right and left gear boxes 9 and 10 are connected to the first worm gear through the cable 14 in the right gear box 9 when the armature shaft 2b1 is rotated forward by the positive power supply connected to the seat motor 2. 15 rotates forward, the first helical gear 17 rotates forward to rotate the first lead screw 7 in the forward direction, and at the same time, the second worm gear 16 together with the armature shaft 2b1 in the left gear box 10.
Rotates forward, the second helical gear 18 rotates forward and the second helical gear 18 rotates forward.
Is rotated in the forward direction.

Contrary to the above, when the armature shaft 2b1 rotates in the reverse direction by connecting the power source on the opposite side to the seat motor 2, the right and left gear boxes 9 and 10 The first worm gear 15 rotates in the reverse direction, the first helical gear 18 rotates in the reverse direction and rotates the first lead screw 7 in the reverse direction, and at the same time, the second gear together with the armature shaft 2b1 in the left gear box 10 The worm gear 16 rotates in the reverse direction, the second helical gear 18 rotates in the reverse direction, and rotates the second lead screw 8 in the reverse direction.

The first lead screw 7 has the other end rotatably supported on the rear side of the vehicle body, which is the other end side of the right lower rail 3, and has one end side located on the front side of the vehicle body and the other end. Since the side is located on the rear side of the vehicle body, the other end is disposed lower than the one end. The first lead screw 7 extends along the right upper rail 5, and has a male thread 7b, which is a two-rolled screw, formed at the center of the shaft body 7a. The male screw 7b forms a part of the torque switching mechanism 13. The first lead screw 7 has a first damper 19 at one end of the male screw 7 b and a first damper 19.
, And a second damper 21 and a second stopper 22 are respectively attached to the other end of the male screw 7b.

Male thread 7b of first lead screw 7
As shown in FIG. 3, the flank angle α1 of the first flank 7b1 on the left side in the figure is 6 degrees. First
The flank angle α1 of the flank 7b1 is selected from the range of 3 degrees to 9 degrees.

As shown in FIG. 3, in the male screw 7b of the first lead screw 7, the flank angle α2 of the second flank 7b2 on the right side in the figure is 29 degrees. The flank angle α2 of the second flank 7b2 is selected from a range of 25 degrees to 33 degrees.

In the first lead screw 7, the first
Of the flank 7b1 of the second flank 7
The reason why the flank angle α2 is extremely smaller than the flank angle α2 is that the force applied to the first lead screw 7 from the later-described first nut body 11 meshed with the male screw 7b of the first lead screw 7 This is because the first lead screw 7 is set to be large in the lead direction, while the first lead screw 7 is set to be small in the vine winding direction.

The second lead screw 8 is provided as a pair with the first lead screw 7, and the other end is rotatably supported on the rear side of the vehicle body, which is the other end of the left lower rail 4. Since one end is located on the front side of the vehicle body and the other end is located on the rear side of the vehicle body, the other end is disposed lower than the one end. The second lead screw 8 extends along the left upper rail 6 and has a male thread 8b which is a two-rolled screw at the center of the shaft body 8a.
Are formed. The male screw 8b forms a part of the torque switching mechanism 13. In the second lead screw 8,
A third damper 23 and a third stopper 24 are respectively attached to one end of the male screw 8b, and a fourth damper 25 and a fourth stopper 26 are respectively attached to the other end of the male screw 8b.

Male screw 8b of second lead screw 8
As shown in FIG. 3, the flank angle α1 of the third flank 8b1 on the left side in the figure is 6 degrees. Third
The flank angle α1 of the flank 8b1 is selected from the range of 3 to 9 degrees.

As shown in FIG. 3, in the male screw 8b of the second lead screw 8, the flank angle α2 of the fourth flank 8b3 on the right side in the figure is 29 degrees. The flank angle α2 of the fourth flank 8b3 is selected from the range of 25 degrees to 33 degrees.

In the second lead screw 8, the third lead screw 8
The flank angle α1 of the flank 8b1 is the fourth flank 8
The reason why the flank angle α2 is extremely smaller than the flank angle α2 is that the force applied to the second lead screw 8 from the second nut body 12 to be meshed with the male screw 8b of the second lead screw 8 The reason for this is to apply a large amount in the lead direction of the second lead screw 8 and a small amount in the helical winding direction of the second lead screw 8.

On the other hand, a first nut body 11 is meshed with the male screw 7b of the first lead screw 7, and a second nut body 12 is meshed with the male screw 8b of the second lead screw 8.
Are engaged.

The first nut body 11 includes a nut body 11b having a female screw 11a formed therein, and a nut housing 11c containing the nut body 11b. The internal thread 11a has an external thread 7b of the first lead screw 7
Is screwed. Internal thread 11 of first nut body 11
a constitutes another part of the rotational force switching mechanism 13. The nut housing 11c is screwed to the right upper rail 5.

As shown in FIG. 3, the female screw 11a of the first nut body 11 has a fifth flank 1 on the left side in the figure.
The flank angle α3 of 1a1 is 6 degrees. The flank angle α3 of the fifth flank 11a1 is selected from a range of 3 to 9 degrees.

The female screw 11a of the first nut body 11
As shown in FIG. 3, the flank angle α4 of the sixth flank 11a2 on the right side in the figure is 29 degrees.
The flank angle α4 is selected from a range of 25 degrees to 33 degrees.

In the first nut body 11, the flank angle α3 of the fifth flank 11a1 is changed to the sixth flank 11a.
The reason why the flank angle α4 is extremely smaller than the flank angle α4 is that the force applied from the first nut body 11 to the first lead screw 7 meshed with the female screw 11a of the first nut body 11 This is because the first lead screw 7 is set to be large in the lead direction, while the first lead screw 7 is set to be small in the vine winding direction.

The second nut body 12 is a first nut body 1
1 and a pair, and the second nut body 12 includes:
A nut body 12b having a female screw 12a formed therein and a nut housing 12c accommodating the nut body 12b are provided. The male screw 8b of the second lead screw 8 is screwed into the female screw 12a. Second nut body 1
The second female screw 12a forms another part of the rotational force switching mechanism 13. The nut housing 12c is screwed to the left upper rail 6.

As shown in FIG. 3, the female screw 12a of the second nut body 12 has a seventh flank 1 on the left side in the figure.
The flank angle α3 of 2a1 is 6 degrees. The flank angle α3 of the seventh flank 12a1 is selected from a range of 3 degrees to 9 degrees.

The female screw 12a of the second nut body 12
As shown in FIG. 3, the flank angle α4 of the eighth flank 12a2 on the right side in the figure is 29 degrees.
The flank angle α4 of the eighth flank 12a2 is selected from the range of 25 degrees to 33 degrees.

In the second nut body 12, the flank angle α3 of the seventh flank 12a1 is changed to the eighth flank 12a.
The reason why the flank angle α4 is extremely smaller than the flank angle α4 of the second nut body 12 is that the force applied from the second nut body 12 to the second lead screw 8 meshed with the female screw 12a of the second nut body 12 This is for the reason that it is set to be large in the lead direction of the lead screw 8, while it is set small in the helical direction of the second lead screw 8.

The first and second nut bodies 11 and 12 have first and second lead screws 7 and 8 because the nut housings 11c and 12c are screwed to the right and left upper rails 5 and 6, respectively. Rotates forward in the clockwise direction when viewed from the right and left gear boxes 9 and 10, respectively.
The seat is moved together with the right and left upper rails 5 and 6 toward the left front side of the vehicle body in FIG. On the other hand, when the first and second lead screws 7 and 8 rotate counterclockwise as viewed from the right and left gear boxes 9 and 10, respectively, the first and second nut bodies 11 and 12 rotate. The seat is moved together with the right and left upper rails 5 and 6 toward the right rear side of the vehicle body in FIG.

When the seat is moved toward the front part of the vehicle body, the first and second lead screws 7 and 8 have the second and fourth flank 7b2 and 8b2 become pressure side flank,
The first and third flanks 7b1 and 8b1 are idle flanks.

Further, the first and second nut bodies 11, 12
Indicates that the sixth and eighth flanks 11a2 and 12a2 are pressure-side flanks and the fifth and seventh flanks 11a1 and 12a
a1 becomes a play side flank.

Therefore, when the seat is moved toward the front part of the vehicle body, the first and second lead screws 7, 8 and the first and second nut bodies 11, 12 are connected to the first and second nut bodies 11, 12, respectively. The rotational force of the lead screws 7 and 8 is large in the helical direction of the first and second nut bodies 11 and 12. And
In this state, the second and fourth flanks 7b2, 8b2 of the first and second lead screws 7, 8 and the sixth and eighth flanks 11a2, 1 of the first and second nut bodies 11, 12 are provided.
2a2 contacts at a pressure angle α1, the first and third flank 7b1, of the first and second lead screws 7, 8
8b1 and the fifth and seventh nut bodies 11 and 12
The transmission efficiency is higher than when the flank 11a1 and 12a1 are in contact with each other at the pressure angle α2.

On the contrary, when the seat is moved toward the rear part of the vehicle body, the right and left lower rails 3 and 4 and the right and left upper rails 5 and 6 are connected to the right and left gear boxes 9 and 10. Since the first and second nut bodies 11 and 12 are inclined upward, the right and left lower rails 3 and 4 have a seat moving downward on the lower side and a right and left seats.
The weight of the upper rails 5 and 6 on the left side is applied.

The first and second lead screws 7 and 8 have the first and third flanks 7b1 and 8b1 as pressure side flanks and the second and fourth flanks 7b2 and 8b.
2 becomes the play side flanks.

Also, the first and second nut bodies 11, 12
Is that the fifth and seventh flanks 11a1 and 12a1 are pressure side flanks and the sixth and eighth flanks 11a2 and 12a
a2 becomes a play-side flank.

Therefore, when the seat is moved toward the rear part of the vehicle body, the first and second lead screws 7, 8 and the first and second nut bodies 11, 12 are attached to the seat and the right and left nuts. In the first and second nut bodies 11 and 12 on which the weights of the upper rails 5 and 6 are applied, the fifth and seventh flank 11a1 and 12a1 having a small flank angle are formed in the first and second lead screws 7 and 8 respectively. The first and second nut bodies 11, 1 are engaged with the first and second flank 7b1, 8b1 having a small flank angle.
2 to the first and second lead screws 7 and 8, a large force is applied in the lead direction of the first and second lead screws 7 and 8, and the force applied to the first and second lead screws 7 and 8 is increased. It takes a small amount in the vine winding direction. In this state, the first and third flanks 7b1 and 8b1 of the first and second lead screws 7 and 8 and the fifth and seventh flanks 11a1 of the first and second nut bodies 11 and 12 are provided. 12
a1 contacts at a pressure angle α2 which is much larger than the pressure angle α1 described above, so that the second and fourth flank 7b2, 8b2 of the first and second lead screws 7, 8 and the first,
Sixth and eighth flank 11 of second nut body 11, 12
The braking is applied as compared with the case where a2 and 12a2 contact at the pressure angle α1.

The rotation force switching mechanism 13 is provided with first and second lead screws 7 and 8 having first and second male screws 7b and 8b, which serve as pressure-side flank when the sheet is moved downward.
The fifth and seventh flank 11a1, which are pressure flank when the seat is moved downward in the third flank 7b1, 8b1 and the female screw 11a, 12a of the first and second nut body 11, 12, 12a1. Therefore, the rotation force switching mechanism 13 includes the first and second lead screws 7 and 8 and the first and second nut bodies 1.
It is formed without enlarging the outer shape of 1 and 12.
Further, since the rotational force switching mechanism 13 is not provided separately from the seat slide device 1, the first and second lead screws 7, 8 and the first and second nut bodies 11,
There is no need for any additional components.

In the seat slide device 1 having such a structure, the right and left upper rails 5 and 6 are attached to the lower surface of the seat, and the right and left lower rails 3 and 4 are fixed to the floor panel and assembled to the vehicle body. Attached.

The armature 2 of the seat motor 2
A controller for connecting a power supply is electrically connected to b. Since the controller is installed in the auto driving position system, it supplies current for manual operation by operating the manual switch, switches the ignition switch from the on position to the off position, and opens the door from the closed state. A current for auto operation is supplied by a detection signal generated when the power is turned on.

When the power switch on the positive side is connected to the armature 2b of the seat motor 2 by switching the manual switch to the forward side, the armature shaft 2b
1 rotates forward, the first worm gear 15 rotates forward in the right gear box 9 and the first helical gear 17 rotates.
Rotates forward, and the first lead screw 7 rotates in the forward direction. At the same time, the second worm gear 16 rotates forward in the left gear box 10, the second helical gear 18 rotates in the reverse direction, and the second lead screw 8 rotates in the forward direction. Accordingly, the first and second nut bodies 11 and 12 move upward together with the right and left upper rails 5 and 6 to the side approaching the right and left gear boxes 9 and 10, so that the seat moves forward.

While the first and second lead screws 7, 8 are rotating in the forward direction, the first and second lead screws 7, 8 are driven by the second and fourth flank 7b2, 8b2 on the pressure side. Become Frank and First and Third Frank 7
b1 and 8b1 are play-side flanks, and the first and second nut bodies 11 and 12 are the sixth and eighth flanks 11a2,
12a2 becomes the pressure side flank and the fifth and seventh flank 11a1 and 12a1 become the play side flank, and the rotational force of the first and second lead screws 7, 8 reduces the first and second nut bodies 11 , 12, the seat is moved toward the front of the vehicle body by being greatly wound in the wrapping direction.

The sheet is moved forward and reaches the foremost position, and the first and second nuts are attached to the first and third dampers 20 and 23 mounted on the first and second lead screws 7 and 8. When the bodies 11 and 12 collide with each other, the rotation of the first and second lead screws 7 and 8 is restricted, and the current supply from the controller is cut off, so that the armature 2b of the seat motor 2 stops rotating. And the sheet stops at the frontmost position.

In the state where the seat is stopped at the frontmost position, contrary to the above, when the manual switch is switched to the retreating side, and the power supply on the opposite side is connected to the armature 2b of the seat motor 2, the armature shaft Since 2b1 rotates in the reverse direction, the first worm gear 15 rotates in the right gear box 9 in the reverse direction, the first helical gear 17 rotates in the reverse direction, and the first lead screw 7 rotates in the reverse direction. At the same time, the second worm gear 16 reversely rotates in the left gear box 10, the second helical gear 18 reversely rotates, and the second lead screw 8 rotates in the reverse direction. Thereby, the first and second nut bodies 11, 1
2 moves down with the right and left upper rails 5 and 6 to the side away from the right and left gear boxes 9 and 10, so that the seat moves backward.

While the first and second lead screws 7, 8 are rotating in opposite directions, the first and second flank 7b1, 8b1 are connected to the pressure side by the first and second flank 7b1, 8b1. Becoming Frank and Second and Fourth Frank 7
b2 and 8b2 are play-side flanks, and the first and second nut bodies 11 and 12 are connected to the fifth and seventh flanks 11a1 and 11b1, respectively.
12a1 becomes the pressure side flank, and the sixth and eighth flank 11a2, 12a2 become the play side flank.

Then, the first and second nut bodies 11, 12
The force applied to the first and second lead screws 7 and 8 is large in the lead direction of the first and second lead screws 7 and 8, while the force of the first and second lead screws 7 and 8 is By taking small in the winding direction,
The seat and the first and second nut bodies 11 and 12 on which the weights of the right and left upper rails 5 and 6 are applied do not increase the rotation speeds of the first and second lead screws 7 and 8 so that the seat is rotated. It is moved toward the rear of the vehicle.

The sheet is moved backward and reaches the last position, and the first and second nuts are attached to the first and third dampers 20 and 23 mounted on the first and second lead screws 7 and 8. When the bodies 11 and 12 collide with each other, the rotation of the first and second lead screws 7 and 8 is restricted, and the current supply from the controller is cut off, so that the armature 2b of the seat motor 2 stops rotating. And the sheet is stopped at the last position.

Unlike the above, when the ignition switch is switched from the on position to the off position while the seat is in the position determined by the occupant and the door is opened from the closed state, the armature 2b of the seat motor 2 is opened. Is supplied to the armature 2b of the seat motor 2 with the power supply on the opposite side to rotate the armature shaft 2b1 in the reverse direction, so that the first and second lead screws 7, 8 rotate in the opposite directions. And the first and second nut bodies 11 and 12 move down with the right and left upper rails 5 and 6 to the side away from the right and left gear boxes 9 and 10, so that the seat starts to move backward.

While the first and second lead screws 7 and 8 are rotating in opposite directions, the first and second flank 7b1 and 8b1 are on the pressure side. Becoming Frank and Second and Fourth Frank 7
b2 and 8b2 are play-side flanks, and the first and second nut bodies 11 and 12 are connected to the fifth and seventh flanks 11a1 and 11b1, respectively.
12a1 becomes the pressure side flank, and the sixth and eighth flank 11a2, 12a2 become the play side flank.

Then, the first and second nut bodies 11, 12
The force applied to the first and second lead screws 7 and 8 is large in the lead direction of the first and second lead screws 7 and 8, while the force of the first and second lead screws 7 and 8 is By taking small in the winding direction,
The seat and the first and second nut bodies 11 and 12 on which the weights of the right and left upper rails 5 and 6 are applied do not increase the rotation speeds of the first and second lead screws 7 and 8 so that the seat is rotated. It is moved toward the rear of the vehicle.

The sheet is moved backward and reaches the last position, and the first and second nuts are attached to the first and third dampers 20 and 23 mounted on the first and second lead screws 7 and 8. When the bodies 11 and 12 collide with each other, the rotation of the first and second lead screws 7 and 8 is restricted, and the current supply from the controller is cut off, so that the armature 2b of the seat motor 2 stops rotating. Then, the seat stops at the rearmost position where the passenger can easily get on and off the vehicle.

As described above, when the seat is moved downward, the first and second nut bodies 11, 12 on which the weight of the seat and the right and left upper rails 5, 6 are applied are:
The first and second lead screws 7 and 8 are the first and second lead screws.
The first and third flanks 7b1 and 8b1 having small flank angles in the lead screws 7 and 8 and the fifth and fifth flank angles having small flank angles in the first and second nut bodies 11 and 12
When the seventh flank 11a1 and the seventh flank 12a1 are meshed with each other, the force applied from the first and second nut bodies 11 and 12 to the first and second lead screws 7 and 8 is increased by the first and second leads. The first and second lead screws 7 and 8 take a large amount in the lead direction, while the first and second lead screws 7 and 8 take a small amount in the helical winding direction, thereby rotating the first and second lead screws 7 and 8. Braking is performed so that the number does not become high.

Although not shown, the right and left gear boxes 9 and 10 are attached to the right and left upper rails 5 and 6, respectively, and the first and second gear boxes 9 and 10 are connected to the right and left gear boxes 9 and 10, respectively. Lead screws 7, 8
May be rotatably supported on the right and left upper rails 9 and 10, and the first and second nut bodies 11 and 12 may be fixed to the right and left lower rails 3 and 4.

In this case, the external thread 7b of the first lead screw 7 is opposite to that shown in FIG.
The flank angle α1 of the flank 7b1 is selected from the range of 25 ° to 33 °, the flank angle α2 of the second flank 7b2 is selected from the range of 3 ° to 9 °, and the second lead screw 8 In the same manner as the first lead screw 7, the third flank 8b1 has a flank angle α1 selected from a range of 25 degrees to 33 degrees, and the fourth flank 8b2 has a flank angle α2 of 3 degrees. It is selected from the range of degrees to 9 degrees.

Then, the female screw 11 of the first nut body 11
a is opposite to that shown in FIG. 3, the flank angle α3 of the fifth flank 11a1 is selected from the range of 25 degrees to 33 degrees, and the flank angle α4 of the sixth flank 11a2 is 3 degrees. And the female screw 12a of the second nut body 12 has a flank angle α3 of the seventh flank 12a1 in the range of 25 to 33 degrees in the same manner as the first nut body 11. And the flank angle α4 of the eighth flank 12a2 is selected from the range of 3 degrees to 9 degrees.

In this case, when the first and second lead screws 7, 8 are rotated in reverse by the seat motor 2, the seat, the right and left upper rails 5, 6, the right and left gear boxes 9, 10 and the first , The second lead screws 7 and 8 are integrated, and the right and left gear boxes 9 and 10 are moved forward away from the first and second nut bodies 11 and 12.

On the other hand, when the first and second lead screws 7, 8 are rotated forward by the seat motor 2, the seat, the right and left upper rails 5, 6, the right and left gear boxes 9, 10 and the The first and second lead screws 7 and 8 are integrated, and the right and left gear boxes 9 and 10 are retracted toward the first and second nut bodies 11 and 12.

The first and second lead screws 7, 8 on which the weight of the seat, the right and left upper rails 5, 6, the right and left gear boxes 9, 10 are applied are first and second nuts. When the sheet is moved backward while meshing with the bodies 11, 12, the first and second lead screws 7, 8 have second and fourth flanks 7b2, 8b2 having a small flank angle, and the first and second nut bodies. 11, 12
6th and 8th flank 11 having a small flank angle
a2 and 12a2 are engaged with each other,
The braking is performed so that the rotation speeds of the first and second lead screws 7 and 8 do not increase.

[0069]

As described above, according to the seat slide device according to the first aspect of the present invention, the seat slide device is disposed between the lead screw and the nut body when the seat is retreating downward. A rotation force switching mechanism reduces the rotation force applied to the lead screw by the movement of the nut body. Therefore, the rotation speed of the lead screw does not increase due to the force given to the nut body by the weight of the sheet, and a rotation force switching mechanism for preventing the rotation speed of the lead screw from increasing is provided by the lead screw and the nut body. Because it is arranged between the two, the components added to the lead screw and the nut body are not required as compared with those in which the braking means is configured separately, so the number of parts does not increase, and the lead screw Also, since the outer shape of the nut body does not change, there is an excellent effect that the outer shape of the entire seat slide device does not increase.

According to the seat slide device of the second aspect of the present invention, when the seat is moving from the front part to the rear part of the vehicle body, the tooth portions of the lead screw and the nut body become the flank of the play side flank. Since the flank angle of the pressure side flank is smaller than the angle, the force applied to the lead screw from the nut body by the weight of the seat and the upper rail due to the weight of the seat and the upper rail is greater in the lead direction of the lead screw, while the lead screw is flared. It takes a small amount in the winding direction. Therefore, the rotation speed of the lead screw does not increase due to the force applied to the nut body, and the lead screw is braked by the teeth formed on the lead screw and the nut body. Therefore, as compared with the case where the braking means is configured separately, no additional parts are required for the lead screw and the nut body, so that the number of parts does not increase and the outer shapes of the lead screw and the nut body change. Therefore, there is an excellent effect that the outer shape of the entire seat slide device does not increase.

In the seat slide device according to the third aspect of the present invention, when the seat is moving from the front to the rear of the vehicle body, the teeth of the lead screw and the nut body have the flank angle of the pressure side flank. The flank angle of the play side flank is smaller than the flank angle of the play side flank because the flank angle of the play side flank is selected from the range of 25 degrees to 33 degrees. Therefore, the force given to the lead screw from the nut body by the weight of the seat and the upper rail is large in the lead direction of the lead screw side teeth of the lead screw, while the helical direction of the lead screw side teeth of the lead screw is large. It takes a little. Therefore,
The rotation speed of the lead screw is not increased by the force applied to the nut body, and the lead screw is formed by the flank angles of the lead screw side teeth formed on the lead screw and the nut body side teeth formed on the nut body. Is braked. Therefore, as compared with the case where the braking means is configured separately, no additional parts are required for the lead screw and the nut body, so that the number of parts does not increase and the outer shapes of the lead screw and the nut body change. Therefore, there is an excellent effect that the outer shape of the entire seat slide device does not increase.

[Brief description of the drawings]

FIG. 1 is a partially broken plan view of an embodiment of a seat slide device according to the present invention.

FIG. 2 is a longitudinal sectional front view around a lead screw in the seat slide device shown in FIG. 1;

FIG. 3 is a cross-sectional view around a tooth portion of a lead screw and a nut body in the seat slide device shown in FIG.

[Explanation of symbols]

 Reference Signs List 1 seat slide device 2 seat motor 2b armature 3 (lower rail) right lower rail 4 (lower rail) left lower rail 5 (upper rail) right upper rail 6 (upper rail) left upper rail 7 (lead screw) first lead screw 7b (tooth (Part) (lead screw side tooth part) Male screw 7b1 (13 rotation force switching mechanism) first flank 7b2 (13 rotation force switching mechanism) second flank 8 (lead screw) second lead screw 8b (tooth part) ( Lead screw side teeth) Male screw 8b1 (13 rotating force switching mechanism) Third flank 8b2 (13 rotating force switching mechanism) Fourth flank 11 (nut body) First nut body 11a (tooth) (nut body side teeth) Part) female screw 11a1 (13 torque switching mechanism) 5th franc H 11a2 (13 rotating force switching mechanism) sixth flank 12 (nut body) second nut body 12a (tooth portion) (nut body side tooth portion) female screw 12a1 (13 rotating force switching mechanism) seventh flank 12a2 (13 Rotational force switching mechanism) Eighth flank

Claims (3)

[Claims] A seat motor provided with an armature that rotates forward or backward depending on the direction of energization; a nut body; a lead arranged in the same direction as the sheet moving direction; A lead screw for moving the sheet forward or backward by moving forward or backward by rotating forward or backward depending on the rotation direction of the armature provided for, disposed between the lead screw and the nut body,
A seat slide device comprising a rotating force switching mechanism capable of changing a rotating force applied to a lead screw by moving the nut body while the sheet is moving backward on the downside. 2. A lower rail which is fixed to the vehicle body side while being inclined downward from a horizontal plane from a front portion to a rear portion of the vehicle body, an upper rail movably mounted along the lower rail, and fixed to a seat. A seat motor having an armature that rotates forward by connecting the power supply in the forward direction and rotates backward by connecting the power supply in the reverse direction, a nut body fixed to the upper rail, and in the same direction as the moving direction of the upper rail. A lead screw meshed with the nut body having a lead and rotated forward or backward by the rotation of the armature of the seat motor includes a lead screw and a nut body in which a seat is directed from a front part to a rear part of a vehicle body. Tooth flank angle of the pressure side flank is smaller than the flank angle of the play side flank when moving Seat slide apparatus characterized by being formed respectively. 3. The lead screw is formed with a lead screw side tooth portion, and the nut body is formed with a nut body side tooth portion that can mesh with the lead screw side tooth portion. The flank angle of the flank of the pressure side flank is selected from 3 degrees to 9 degrees,
The seat slide device according to claim 2, wherein the flank angle of the play-side flank is selected in a range of 25 degrees to 33 degrees.