Device for preventing wheel lock of vehicle

A device for preventing wheel lock of a vehicle in which an engine output power is transmitted to front and rear wheels of the vehicle through a transmission and an inter axle differential, said device comprising:

• a differential lock mechanism for locking said inter axle differential;
• means for detecting a wheel lock state of the front and rear wheels during a braking operation of respective front and rear wheel brakes;
• and
• means for operating the differential lock mechanism so as to lock the inter axle differential by operating the differential lock mechanism upon the detection of the wheel lock state during the braking operation;
• wherein said wheel lock detection means is operated to detect the wheel lock state in a case where a relative revolution number difference between a transmission output revolution number and a differential revolution number in a braking state of the respective front and rear wheel brakes is more than a set revolution number;
• wherein said differential lock mechanism operating means comprises a differential lock valve that discharges pressurized oil to the differential lock mechanism, and said differential lock valve is operated upon the detection of the wheel lock state during the braking operation to thereby discharge the pressurized oil;
• wherein said wheel lock detection means stores a plurality of set revolution numbers and is operated to generate a wheel lock signal in accordance with the wheel lock state upon the detection of the wheel lock state during the braking operation in a case where said relative revolution number difference is more than each of said set revolution numbers stored in the wheel lock detection means, and
• wherein the pressurized oil discharged by said differential lock valve has a pressure in accordance with the detected wheel lock signal so as to create a differential lock state in accordance with the wheel lock state.