Patent ID: 7954558

Claim:
A horizontal directional drilling machine having power control, comprising: an engine that outputs mechanical energy through a rotation shaft; a rotation pump that draws upon the mechanical energy output by the engine through rotation of the rotation shaft to operate a rotation motor that rotates a drill string by pressurization of a rotation hydraulic fluid circuit between the rotation pump and the rotation motor; a thrust pump that draws upon the mechanical energy output by the engine through rotation of the rotation shaft to operate a thrust motor that longitudinally moves the drill string by pressurization of a thrust hydraulic fluid circuit between the thrust pump and the thrust motor; a mud pump that draws upon the mechanical energy output by the engine through rotation of the rotation shaft to operate a mud motor that delivers fluid through the drill string by pressurization of a mud hydraulic fluid circuit between the mud pump and the mud motor; a rotation hydraulic fluid sensor that outputs a rotation pressure signal indicative of hydraulic fluid pressure within the rotation hydraulic fluid circuit; a thrust hydraulic fluid sensor that outputs a thrust pressure signal indicative of hydraulic fluid pressure within the thrust hydraulic fluid circuit; a mud hydraulic fluid sensor that outputs a mud pressure signal indicative of hydraulic fluid pressure within the mud hydraulic fluid circuit; a sensor that outputs a rotation signal indicative of rotation rate of the rotation shaft; and control circuitry comprising a processor and memory, the processor configured to execute program instructions stored in the memory, processor execution of the stored program instructions causing the control circuitry to control power draw of the rotation pump from the mechanical energy output by the engine, control power draw of the thrust pump from the mechanical energy output by the engine, control power draw of the mud pump from the mechanical energy output by the engine, calculate a rotation pump power draw from the engine based on the rotation pressure signal and the rotation signal, calculate a thrust pump power draw from the engine based on the thrust pressure signal and the rotation signal, calculate a mud pump power draw from the engine based on the mud pressure signal and the rotation signal, calculate a total power draw based on the rotation pump power draw, the thrust pump power draw and the mud pump power draw, compare the total power draw to a threshold associated with output capacity of the engine, and decrease mechanical energy draw from the engine of each of the rotation pump, the thrust pump, and the mud pump based on the total power draw exceeding the threshold, the processor executing the stored program instructions to cause the control circuitry to decrease the mechanical energy draw of each of the rotation pump, the thrust pump, and the mud pump in different amounts based on the total power draw exceeding the threshold.