Height adjustment apparatus of vehicle seat

1. A height adjustment apparatus of a vehicle seat having a cushion frame, a position of which is adjusted in upward/downward directions on a seat rail, the height adjustment apparatus comprising:

a height link having a plurality of links, the height link being rotatably coupled to a side frame of the cushion frame and to the seat rail, and allowing the cushion frame to be moved in the upward/downward directions by the plurality of links being unfolded or folded;

a drive unit provided on the cushion frame, the drive unit including a power transmission part changeable in a length in forward/rearward directions during an operation of the drive unit; and

a drive mechanism connected to the power transmission part and the height link for operating in cooperation with the drive unit and the height link such that as the length of the power transmission part is increased during the operation of the drive unit, the plurality of links constituting the height link unfolds for the cushion frame to lift,

wherein the height link includes a first link rotatably provided on the seat rail and a second link rotatably provided on the side frame, and wherein the first link is rotatably coupled to the second link.

2. The height adjustment apparatus of claim 1 , wherein a guide slot curvedly extended as an arc shape is provided on the side frame, and a guide part is provided on a connection portion between the first link and the second link of the height link, and

wherein the guide part is placed in and passes through the guide slot.

3. The height adjustment apparatus of claim 2 , wherein after the guide slot extends downward from an upper side thereof, the guide slot is configured to extend in an advancing direction of the power transmission part.

4. The height adjustment apparatus of claim 1 , wherein the first link is provided by extending so as to bend upward and a reinforcement bead is provided by bending along an edge of the first link.

5. The height adjustment apparatus of claim 1 , wherein the drive unit includes a drive motor fixed to the cushion frame and the power transmission part advancing and withdrawing during an operation of the drive motor, and

wherein the drive motor is provided to incline upward such that the power transmission part advances to incline upward.

6. The height adjustment apparatus of claim 1 , wherein the drive mechanism includes;

a rotation link rotatably provided on a front end of the power transmission part;

a first connection bar, each of opposite ends of which is rotatably connected to a connection portion between the first link and the second link and being in contact with a front end part of the rotation link; and

a second connection bar, each of opposite ends of which is rotatably connected to a connection portion between the second link and the side frame and being connected to an end part of the rotation link.

7. The height adjustment apparatus of claim 6 , wherein the rotation link includes a holding part provided on the front end part thereof such that the first connection bar is placed in the holding part so as to be held in and connected to the holding part.

8. The height adjustment apparatus of claim 6 , wherein the first connection bar includes a middle portion being in contact with the front end part of the rotation link and a connection end portion connected to the connection portion between the first link and the second link after each of opposite ends of the first connection bar is bended.

9. The height adjustment apparatus of claim 1 , further comprising:

a gear link having a first end part rotatably connected on the seat rail and a second end part rotatably connected on the cushion frame, the gear link having gear teeth provided on a portion of a circumference of the gear link; and

an operation unit provided on the cushion frame, the operation unit having a drive gear engaged with the gear teeth of the gear link,

wherein the gear link is rotated on the seat rail by a rotation of the drive gear during an operation of the operation unit so as to lift and lower the cushion frame.

10. The height adjustment apparatus of claim 9 , wherein an extension slot is provided on the gear link and the extension slot is extended curvedly along a curve of the gear teeth that is extended, and

a protrusion is provided on the side frame so as to be placed in the extension slot.

11. The height adjustment apparatus of claim 9 , wherein the height link, the drive unit, and the drive mechanism are provided on front portions of the seat rail and the cushion frame, and

the gear link and the operation unit are provided on rear portions of the seat rail and the cushion frame.

12. The height adjustment apparatus of claim 9 , further comprising:

a controller controlling the drive unit and the operation unit,

wherein the controller operates the drive unit and the operation unit so as to adjust a height and an angle of the cushion frame such that a hip-point of a seated passenger is changed.

13. The height adjustment apparatus of claim 12 , wherein when the controller operates the drive unit and the operation unit to adjust the height of the cushion frame, the plurality of links constituting the height link is rotated and unfolded by the operation of the drive unit and the gear link is rotated by the operation of the operation unit, so that the hip-point is changed while tracing a curve forward.

14. The height adjustment apparatus of claim 12 , wherein when the controller operates the drive unit so as to adjust the angle of the cushion frame, the plurality of links constituting the height link is rotated and unfolded by the operation of the drive unit, so that the hip-point is changed while tracing a curve rearward.