SEAT SLIDE DEVICE FOR VEHICLE

PROBLEM TO BE SOLVED: To provide a seat slide device for a vehicle capable of preventing the detachment operation of a lock lever caused by front collision with a simple structure and effectively.SOLUTION: A lock mechanism has a lock lever 31 which has a rotation shaft M crossing both sidewall parts 15 and is supported by an upper rail 6. In addition, engaging projection parts 36 projecting in the width direction are provided at one end of the lock lever 31 and insertion holes 37 to which the engaging projection parts 36 are vertically movably inserted are provided at each of sidewall parts 15. In addition, a plurality of engaging holes 38 having an upper opening part with which the engaging projection parts 36 can be detachably engaged based on the rotation of the lock lever 31 are provided on a lower rail 5. Further, a notch 52 is formed on a rear inner surface 51 of an insertion hole 37a. Then, the upward movement of engaging projection parts 36 is regulated since the rear inner surface 51 is inclined forward by the deformation of the upper rail 6 in the case of front collision of a vehicle.