English to French Other Patents construction machine, hydraulic pump, upper operation lever

the term swing here is associated with many terms : swing motor, swing pressure, swing acceleration , upper swing structure, swing operation lever

The présent invention relates to a method for contrelling flow rate of hydraulic pump, and more particularly, a method for contre lling a discharge flow rate of hydraulic pump for construction machine in which the discharge flow rate can be restricted when an upper swing structure is suddenly revolved.

Figure 1 is a hydraulic circuit of a swing control apparatus for construction machine according to the conventional technology.

A swing motor (4) that revolves an upper swing structure (not shown in figure) is connected to the hydraulic pump (2) which is driven by working oil.
A main control valve (MCV) (5) is installed in the flow path between the hydraulic pump (2) and the swing motor (4), which Controls the working oil that is supplied from the hydraulic pump (2) to the swing motor (4).

At the moment when the upper swing structure is rotated by operation of the swing operation lever (7), the working oil is unnecessarily or excessively supplied to the swing motor (4) from swing start to swing accélération, which leads to the maximum discharge flow rate of the hydraulic pump (2), and thus not only causes the loss of hydraulic energy, but increases the füel consumption
an electric proportional valve for controlling the working oil supplied to the swing motor from the hydraulic pump; a pressure sensor for detecting a swing pressure generated in the swing motor; and a controller to which the detected signais are inputted from the détection means and the pressure sensor,

step of calculating the first slope a first gradient value of the swing accélération to increase the a discharge flow rate of of the hydraulic pump from the swing start, when the upper swing structure is to be rotatedrevolved;