Method for automatically controlling hydraulic opener

An automatic control method for a hydraulic taphole opener for opening a taphole by giving impact and rotation to a drill unit holding a drilling rod and driving the drill unit forward and backward by a hydraulically driven feed motor, which method comprises the steps of:

• detecting the driving load in the form of detected hydraulic pressure;
• maintaining the impact when said detected pressure is equal to or higher than a set value to commence the impact;
• and
• stopping the impact when said detected pressure is lower than said set value.

An automatic control method for a hydraulic taphole opener for opening a taphole by giving impact and rotation to a drill unit holding a drilling rod and driving the drill unit forward and backward by a hydraulically driven feed motor, which method comprises the steps of:

• detecting the driving load in the form of detected pressure;
• setting the count of position detection to zero when the detected pressure exceeds an upper limit set value for detecting that the drill unit has reached a plugging material in the taphole, commencing position detection from this position, and calculating the depth of the taphole;
• stopping the driving of the drilling rod when the taphole depth according to the position detection becomes equal to or deeper than a set value and the detected pressure becomes equal to or lower than a lower limit set value for detecting that the taphole has been perforated;
• stopping the driving but maintaining the rotation when, during the forward driving of the drilling rod, said detected pressure reaches an upper limit set value beyond which buckling may occur;
• and
• resuming the driving when said detected pressure falls to a lower limit set value or below.

An automatic control method for a hydraulic taphole opener for opening a taphole by giving impact and rotation to a drill unit holding a drilling rod and driving the drill unit forward and backward by a hydraulically driven feed motor, which method comprises the steps of:

• detecting the driving load in the form of detected pressure;
• setting the count of position detection to zero when the detected pressure exceeds an upper limit set value for detecting that the drill unit has reached a plugging material in the taphole, commencing position detection from this position, and calculating the depth of the taphole;
• stopping the driving of the drilling rod when the taphole depth according to the position detection becomes equal to or deeper than a set value and the detected pressure becomes equal to or lower than a lower limit set value for detecting that the taphole has been perforated;
• maintaining the impact when, during the forward driving of the drilling rod, said detected pressure is equal to or higher than a set value to commence the impacts;
• and
• stopping the impact when said detected pressure is lower than said set value.

An automatic control method for a hydraulic taphole opener for opening a taphole by giving impact and rotation to a drill unit holding a drilling rod and driving the drill unit forward and backward by a hydraulically driven feed motor, which method comprises the steps of:

• detecting the driving load in the form of detected pressure;
• setting the count of position detection to zero when the detected pressure exceeds an upper limit set value for detecting that the drill unit has reached a plugging material in the taphole, commencing position detection from this position, and calculating the depth of the taphole;
• stopping the driving of the drilling rod when the taphole depth according to the position detection becomes equal to or deeper than a set value and the detected pressure becomes equal to or lower than a lower limit set value for detecting that the taphole has been perforated;
• stopping the driving but maintaining the rotation when, during the forward driving of the drilling rod, said detected pressure reaches an upper limit set value beyond which buckling may occur;
• resuming the driving when said detected pressure falls to a lower limit set value or below;
• further, maintaining the impact when, during the forward driving of the drilling rod, said detected pressure is equal to or higher than a set value to commence the impact;
• and
• stopping the impact when said detected pressure is lower than said set value.