PURPOSE: To improve reliability by arranging spike pins which can advance and retreat in the radial direction in radial form on a body on which wheel installation holes are formed and connecting spike pins with a sliding body which is installed in slidable and lock-enabled state in the circumferential direction on the body by a damper.

CONSTITUTION: In the case of the traveling on a normal road surface, spike pins 8 are accommodated in a device body 2, and locking pins 27b are inserted into locking holes 23, and a sliding body 15 is fixed. On a frozen road, the lock pin 27b is pushed out from the locking hole 23 by a tool 32 consisting of a cross bar 31 and a pushing pin 31, and the sliding body 15 is turned in the C direction by the tool 32. Accordingly, the spike pin 8 is projected in the C direction. When the locking hole 23 of the sliding body 15 comes to the position of a pin hole 24a, the tool 23 is pulled out, Then, the locking pin 27a is inserted into the locking hole 23, and the sliding body 15 is fixed, and the spike pin 8 projects in the radial form, and a spike state is generated.