| 摘要 |
PURPOSE:To reduce the discomfort feeling of an operator and improve the durability of a device with the abrasion in each part reduced by making constitution in which an oil temperature is quickly raised with the supply pressure of a hydraulic pump made higher than usual in starting an engine. CONSTITUTION:The starting of an engine with a key switch turned on is confirmed, after that the set oil temperature of an oil temperature detected with an oil temperature sensor 16 is ascertained, and when the oil temperature is the set oil temperature or more, the control is made by normal algorithm with the set pressure of a relief valve 11 made the maximum normal value, and when below the set oil temperature, the oil temperature is made to be quickly raised by sending control current to an electronic pressure controller so that the set pressure of the relief valve 11 can become higher than the maximum normal value. A time from the start of an engine is always confirmed as safety measures, and when a set time elapses, the set pressure of the relief valve 11 is lowered to make a normal condition. This can prevent the abnormal high temperature of an oil temperature when an oil temperature sensor 16 fails. |
