Variable displacement pump, oil jet and lublicating system using variable displacement pump

Abstract

A variable displacement pump arranged to supply a hydraulic fluid to an oil jet arranged to inject the hydraulic fluid to a piston of an internal combustion engine, the variable displacement pump includes: a pump constituting section arranged to be driven and rotated by the internal combustion engine, and thereby to discharge the hydraulic fluid; a movable member arranged to decrease the flow rate discharged from the discharge portion by moving in one direction; a control section configured to move the movable member in the one direction by a predetermined amount when the discharge pressure becomes a first discharge pressure, and to further move the movable member in the one direction when the discharge pressure becomes a second discharge pressure larger than the first discharge pressure, the first discharge pressure being set smaller than the predetermined pressure at which the oil jet starts to inject the hydraulic fluid.

1 . A variable displacement pump arranged to supply a hydraulic fluid to an oil jet arranged to inject the hydraulic fluid to a piston of an internal combustion engine when a pressure of the supplied hydraulic fluid becomes equal to or greater than a predetermined pressure, the variable displacement pump comprising:
 a pump constituting section arranged to be driven and rotated by the internal combustion engine, and thereby to discharge the hydraulic fluid entered from a suction portion to a plurality of operation chambers, from a discharge portion by volume variations of the operation chambers;   a movable member arranged to decrease the flow rate of the hydraulic fluid discharged from the discharge portion by moving in one direction; and   a control section configured to move the movable member in the one direction by a predetermined amount when the discharge pressure of the hydraulic fluid becomes a first discharge pressure, and to further move the movable member in the one direction when the discharge pressure of the hydraulic fluid becomes a second discharge pressure larger than the first discharge pressure,   the first discharge pressure being set smaller than the predetermined pressure at which the oil jet starts to inject the hydraulic fluid.   
     
     
         2 . The variable displacement pump as claimed in  claim 1 , wherein the second discharge pressure is set larger than the predetermined pressure at which the oil jet starts to inject the hydraulic fluid. 
     
     
         3 . The variable displacement pump as claimed in  claim 1 , wherein the oil jet includes;
 a body including a hydraulic fluid supplying portion to which the hydraulic fluid is supplied, a hydraulic fluid introducing portion arranged to introduce the hydraulic fluid supplied to the hydraulic fluid supplying portion, and a valve seat formed between the hydraulic fluid supplying portion and the hydraulic fluid introducing portion;   a valve element arranged to be seated on and released from the valve seat in accordance with the pressure of the hydraulic fluid supplied to the hydraulic fluid supplying portion, and thereby to open and close the hydraulic fluid supplying portion;   an urging member arranged to urge the valve element in a valve closing direction in which the valve element closes the hydraulic fluid supplying portion, and to set a valve opening pressure of the valve element at which the valve element opens the hydraulic fluid supplying portion, to a value larger than the first discharge pressure; and   an injection nozzle connected on a downstream side of the hydraulic pressure introducing portion, and arranged to inject the hydraulic fluid from an injection opening toward the piston.   
     
     
         4 . The variable displacement pump as claimed in  claim 1 , wherein the movable member is a cam ring having a cam surface formed on an inner circumference surface thereof; the pump forming section includes a rotor arranged to be driven and rotated by the internal combustion engine, and vanes disposed on an outer circumference portion of the rotor, and arranged to be moved in a radially inward direction or in a radially outward direction, and to be moved in the radially outward direction toward the inner circumference surface to separate the plurality of the operation chambers; and the cam ring is arranged to move to vary an eccentric amount of the cam ring with respect to a center of the rotor. 
     
     
         5 . The variable displacement pump as claimed in  claim 4 , wherein the discharged hydraulic fluid lubricates sliding portions of the internal combustion engine. 
     
     
         6 . The variable displacement pump as claimed in  claim 1 , wherein the discharged hydraulic fluid activates a valve timing control apparatus arranged to vary a relative rotational phase between a driving rotational member and a cam shaft of the internal combustion engine, and a lock mechanism of the valve timing control apparatus; and the lock mechanism has a release pressure at which a lock of the lock mechanism is released, and which is set smaller than the first discharge pressure. 
     
     
         7 . A lubricating system comprising:
 an oil jet arranged to inject a hydraulic fluid to a piston of an internal combustion engine when a pressure of a supplied hydraulic fluid becomes equal to or greater than a predetermined pressure; and   a variable displacement pump arranged to supply the hydraulic fluid to the oil jet, the variable displacement pump including;
 a pump constituting section arranged to be driven and rotated by the internal combustion engine, and thereby to discharge the hydraulic fluid entered from a suction portion to a plurality of operation chambers, from a discharge portion by volume variations of the operation chambers; 
 a movable member arranged to decrease the flow rate of the hydraulic fluid discharged from the discharge portion by moving in one direction; and 
 a control section configured to move the movable member in the one direction by a predetermined amount when the discharge pressure of the hydraulic fluid becomes a first discharge pressure, and to further move the movable member in the one direction when the discharge pressure of the hydraulic fluid becomes a second discharge pressure larger than the first discharge pressure, 
   the first discharge pressure being set smaller than the predetermined pressure at which the oil jet starts to inject the hydraulic fluid.   
     
     
         8 . An oil jet comprising:
 a body including a hydraulic fluid supplying portion to which a hydraulic fluid is supplied, a hydraulic fluid introducing portion arranged to introduce the hydraulic fluid supplied to the hydraulic fluid supplying portion, and a valve seat formed between the hydraulic fluid supplying portion and the hydraulic fluid introducing portion;   a valve element arranged to be seated on and released from the valve seat in accordance with the pressure of the hydraulic fluid supplied to the hydraulic fluid supplying portion, and thereby to open and close the hydraulic fluid supplying portion;   an urging member arranged to urge the valve element in a valve closing direction in which the valve element closes the hydraulic fluid supplying portion, and to set a valve opening pressure of the valve element at which the valve element opens the hydraulic fluid supplying portion, to a value larger than the first discharge pressure; and   an injection nozzle connected on a downstream side of the hydraulic pressure introducing portion, and arranged to inject the hydraulic fluid from an injection opening toward the piston,   the hydraulic fluid supplying portion of body receiving the supply of the hydraulic fluid from a variable displacement pump including a pump constituting section arranged to be driven and rotated by an internal combustion engine, and thereby to discharge the hydraulic fluid entered from a suction portion to a plurality of operation chambers, from a discharge portion by volume variations of the operation chambers, a movable member arranged to decrease the flow rate of the hydraulic fluid discharged from the discharge portion by moving in one direction, and a control section configured to move the movable member in the one direction by a predetermined amount when the discharge pressure of the hydraulic fluid becomes a first discharge pressure, and to further move the movable member in the one direction when the discharge pressure of the hydraulic fluid becomes a second discharge pressure larger than the first discharge pressure,   the valve element of the body being arranged to open the hydraulic fluid supplying portion to inject the hydraulic fluid to a piston of the internal combustion engine when a pressure of the supplied hydraulic fluid becomes equal to or greater than a predetermined pressure larger than the first discharge pressure.   
     
     
         9 . The oil jet as claimed in  claim 8 , wherein the oil jet is arranged to start to inject the hydraulic fluid at the predetermined pressure smaller than the second discharge pressure.