JPWO2016163302A1 - Variable displacement oil pump - Google Patents

Abstract

An electromagnetic switching valve 40 formed so as to be switchable between a state in which the hydraulic oil is discharged from the second control oil chamber 32 and a state in which the hydraulic oil is introduced into the second control oil chamber, a discharge pressure by the hydraulic oil, and a control spring 55 The hydraulic pressure is supplied to or interrupted from the first control oil chamber 31 according to the discharge pressure, and the hydraulic pressure is supplied to the second control oil chamber 32 via the electromagnetic switching valve 40, the intermediate passage 70, and the like. In a variable displacement oil pump that includes a pilot valve 50 that supplies or discharges and controls the pump discharge pressure to a two-stage characteristic, a control spring housing chamber 54 in which a control spring 55 of the pilot valve 50 is disposed is provided inside the first, The hydraulic oil discharged from the second control oil chambers 31 and 32 is not guided. Thereby, the control accuracy of the pump discharge pressure with respect to the set hydraulic characteristic can be improved.

Description

  The present invention relates to a variable displacement oil pump that supplies oil as a driving source for, for example, lubrication of a sliding portion of an internal combustion engine and auxiliary equipment of the internal combustion engine.

  As a conventional variable displacement oil pump, one described in Patent Document 1 below is known. This oil pump supplies hydraulic pressure to the first and second control oil chambers from the main oil gallery formed on the downstream side of the discharge passage, or discharges it through the drain passage, thereby preventing the cam ring rotor. The amount of eccentricity is changed.

  That is, the first control oil chamber moves the cam ring in a direction in which the amount of eccentricity is reduced by introducing the hydraulic pressure supplied from the first branch passage branched from the main oil gallery. ing. On the other hand, the second control oil chamber moves the cam ring in the direction in which the eccentric amount increases by introducing the hydraulic pressure supplied from the second branch passage branched from the main oil gallery. Yes.

  The introduction of the hydraulic pressure into the second control oil chamber is controlled on and off by a switching operation of an electromagnetic switching valve provided in the second branch passage, whereby the pump discharge pressure is reduced and It is controlled to a two-stage characteristic of high pressure.

  Each branch passage is provided with a pilot valve for adjusting the amount of hydraulic oil supplied to or discharged from each control oil chamber to stabilize the two-stage characteristics.

  In this pilot valve, a spool valve slidably accommodated inside is controlled based on a differential pressure between the hydraulic pressure supplied from the main oil gallery and the urging force of a valve spring provided therein. The hydraulic pressure is appropriately supplied to or discharged from each control oil chamber according to the control position. When the hydraulic pressure is discharged from each control oil chamber, each control oil chamber and the outside of the pump are connected to each other via a spring housing chamber that houses the valve spring and a drain port that is formed through a peripheral wall of the spring housing chamber. To communicate with each other.

  However, as described above, the conventional oil pump discharges the hydraulic oil in each control chamber via the spring accommodating chamber of the pilot valve. As a result, the pressure in the spring accommodating chamber rises, and as a result, the internal differential pressure of the pilot valve fluctuates, and the behavior of the spool valve becomes unstable, and the pump discharge pressure is set to a preset hydraulic characteristic. There was a risk of loss of control.

JP 2014-105623 A

  The present invention has been devised in view of the above-described conventional technical problems, and an object thereof is to provide a variable displacement oil pump that can improve the control accuracy of pump discharge pressure with respect to a set hydraulic characteristic.

  According to the present invention, the volumes of the plurality of pump chambers are changed by being rotationally driven by the internal combustion engine, and the plurality of pump chambers that discharge the hydraulic oil sucked from the suction portion from the discharge portion are moved. A movable member that changes the volume change amount of the pump chamber, and a biasing mechanism that is provided with a set load applied thereto and biases the movable member in a direction in which the volume change amount of the plurality of pump chambers increases; A first control oil chamber that causes the movable member to act on the movable member in a direction in which the volume change amount of the plurality of pump chambers is reduced by supplying the hydraulic oil, and the plurality of the plurality of the plurality of pump chambers by supplying the hydraulic oil. A second control oil chamber that causes the movable member to exert a force in a direction to increase the volume change amount of the pump chamber, a state in which hydraulic oil is discharged from the second control oil chamber, and a second control oil chamber. Introducing hydraulic fluid A switching mechanism formed to be switchable, and a state in which the hydraulic oil in the first control oil chamber is discharged when the switching mechanism is in a state of discharging the hydraulic oil from the second control oil chamber; The hydraulic oil is introduced into the first control oil chamber in a state where the hydraulic oil whose pressure is lower than the discharge pressure from the discharge portion is introduced, and the hydraulic oil is introduced into the first control oil chamber as the discharge pressure increases. When the pressure in the first control oil chamber is adjusted and the switching mechanism is in a state of introducing hydraulic oil into the second control oil chamber, the discharge from the discharge section to the second control oil chamber A state in which the hydraulic oil whose pressure is lower than the pressure is introduced, and a state in which the introduction of the hydraulic oil to the second control oil chamber via the switching mechanism is blocked and the hydraulic oil in the second control oil chamber is discharged. In addition, as the discharge pressure increases, the inside of the second control oil chamber A control mechanism for adjusting the pressure in the second control oil chamber by discharging the hydraulic oil, and the control mechanism is controlled by the hydraulic pressure by the hydraulic oil and the biasing force by the biasing member, and the biasing member It is characterized in that hydraulic oil is not guided to the portion where is disposed.

  According to the present invention, it is possible to improve the control accuracy of the pump discharge pressure with respect to a preset hydraulic characteristic.

It is the schematic which shows the oil pump and hydraulic circuit of the variable displacement oil pump which concern on embodiment of this invention. It is a front view which shows the state which removed the cover member of the oil pump provided to this embodiment. It is a longitudinal cross-sectional view of the oil pump of this embodiment. It is a front view which shows the pump body of the oil pump provided to this embodiment. It is a longitudinal cross-sectional view of the electromagnetic switching valve provided for this embodiment. It is a longitudinal cross-sectional view of the pilot valve provided for this embodiment. It is operation | movement explanatory drawing of the variable displacement type oil pump. It is operation | movement explanatory drawing of the variable displacement type oil pump. It is operation | movement explanatory drawing of the variable displacement type oil pump. It is a graph which shows the relationship between the engine speed and pump discharge pressure in the variable displacement oil pump which concerns on the same embodiment. It is a longitudinal cross-sectional view which shows the pilot valve of 2nd Embodiment of this invention. It is a longitudinal cross-sectional view of the pilot valve which shows the example of a change of 2nd Embodiment.

Hereinafter, each embodiment of the variable displacement oil pump according to the present invention will be described in detail with reference to the drawings.
[First Embodiment]
FIG. 1 shows a variable displacement oil pump and a hydraulic circuit according to this embodiment. A variable displacement oil pump 10 is rotated by a rotational driving force transmitted from a crankshaft of an internal combustion engine and stored in an oil pan 01. After being sucked from the suction passage 03 via the strainer 02, the oil which is the working oil is discharged from the discharge passage 04 to the main oil gallery 05 formed in the engine.

  The relief passage 06 branched from the discharge passage 04 is provided with a check ball type relief valve 07 that returns oil into the oil pan 01 when the pump discharge pressure rises excessively.

  Further, on the downstream side of the relief passage 06 of the discharge passage 04, foreign matter in the oil is removed by an unillustrated oil cooler used for cooling the oil flowing through the inside or a metallic mesh portion not shown. A first oil filter 1 for collecting is provided.

  Further, a bypass passage 08 that bypasses the upstream side and the downstream side of the first oil filter 1 is provided at a predetermined portion of the discharge passage 04 sandwiching the first oil filter 1. When the first oil filter 1 is clogged, for example, and the oil flow becomes difficult, the bypass passage 08 is opened to allow the upstream side and the downstream side of the bypass passage 08 to communicate with each other. A check ball type bypass valve 09 is provided.

  The main oil gallery 05 supplies oil to a sliding portion of the engine, for example, an oil jet that injects cooling oil onto a piston, a variable valve device (valve timing control device), and a crankshaft bearing. Yes. That is, the oil flowing through the main oil gallery 05 is not only used as a lubricating oil for lubricating the components included in the engine, but is also cooled by the drive source of the variable valve operating device and the oil jet. It is also used as an oil.

  A first branch passage 3 is branched in the middle of the main oil gallery 05. The first branch passage 3 is provided with the second oil filter 2 in the upstream portion, and further, the second and third branch passages 4 and 5 are further branched from the downstream end portion.

  As shown in FIG. 5, the second oil filter 2 includes a substantially cylindrical main body 2a press-fitted to the inner peripheral surface of the first branch passage 3, and a bottomed body coupled to one end of the main body 2a. The cylindrical metal mesh portion 2b is configured to prevent contamination mixed into the oil from flowing into an electromagnetic switching valve 40 described below.

  The first and second oil filters 1 and 2 are each a cartridge type in which the mesh portions are detachable, and can be replaced when clogging or the like occurs. The first and second oil filters 1 and 2 may perform oil filtration with filter paper attached in a replaceable manner.

  As shown in FIG. 2, the second branch passage 4 can communicate with a first control oil chamber 31 (to be described later) of the oil pump 10 through a pilot valve 50 and a first supply / discharge passage 7a which are control mechanisms. ing. On the other hand, the third branch passage 5 is connected to the oil pump 10 via an electromagnetic switching valve 40 which is a switching mechanism that is electrically controlled and switched, an intermediate passage 70, the pilot valve 50, and the second supply / discharge passage 7b. It is possible to communicate with a second control oil chamber 32 described later.

  The oil pump 10 is provided at the front end of a cylinder block 35 of an internal combustion engine, etc., and as shown in FIGS. 2 to 4, the oil pump 10 is formed so that one end side is open and has a pump housing chamber 13 inside. A pump body 11 having a shape and a cover member 12 that closes one end opening of the pump body 11, and a housing that is rotatably supported by the housing and penetrates substantially the center of the pump housing chamber 13. And a drive shaft 14 that is rotatably supported by the cover member 12 and that is driven by the crankshaft of the engine, and is rotatably accommodated in the pump housing chamber 13, and a central portion is coupled to the drive shaft 14. Rotor 15 and a plurality of bases respectively housed in a plurality of slits 15a radially cut out on the outer periphery of the rotor 15. 16 and a plurality of pump chambers together with the rotor 15 and the adjacent vanes 16 and 16 are arranged on the outer peripheral side of each vane 16 so as to be eccentrically swingable (movable eccentrically) with respect to the rotation center of the rotor 15. And a cam ring 17 which is a movable member separating 20, and is housed in the pump body 11, and constantly biases the cam ring 17 in a direction in which an eccentric amount with respect to the rotor 15 (hereinafter simply referred to as “eccentric amount”) increases. A cam spring 18 that is an urging mechanism, and a pair of ring members 19 and 19 that are slidably disposed at both ends on the inner peripheral side of the rotor 15 and have a smaller diameter than the rotor 15; It has. The drive shaft 14, the rotor 15, and the vanes 16 are pump components.

  The pump body 11 is integrally formed of an aluminum alloy material, and rotatably supports one end portion of the drive shaft 14 at a substantially central position of the bottom surface 13a of the pump housing chamber 13 as shown in FIGS. A bearing hole 11a is formed through. Further, as shown in FIG. 4, a pivot pin 24 which is a swing fulcrum for swingably supporting the cam ring 17 is inserted into a predetermined position on the inner peripheral wall of the pump housing chamber 13 which is the inner surface of the pump body 11. The support hole 11b to be fixed is notched. A holding groove 11e that holds oil and serves to lubricate the drive shaft 14 is formed on the inner peripheral surface of the bearing hole 11a.

  Further, as shown in FIG. 2, a straight line (hereinafter referred to as “cam ring reference line”) M connecting the center of the bearing hole 11 a and the center of the support hole 11 b is sandwiched between the inner peripheral walls of the pump housing chamber 13. On both sides, there are formed first and second seal slidable contact surfaces 11c and 11d, which are slidably contacted with two seal members 30 and 30 (to be described later) disposed on the outer periphery of the cam ring 17, respectively. As shown in FIG. 4, each of the seal sliding contact surfaces 11c and 11d is formed in a circular arc shape with predetermined radii R1 and R2 from the center of the support hole 11b.

  Further, as shown in FIG. 2 and FIG. 4, the inner volume of the pump chamber 20 is increased on the bottom surface 13 a of the pump housing chamber 13 in the outer peripheral area of the bearing hole 11 a with the pump action of the pump structure. A suction port 21 that is a substantially arc-shaped concave suction portion that opens to a region (suction region) that opens, and a region (discharge region) in which the internal volume of the pump chamber 20 decreases with the pump action of the pump component. The discharge port 22 which is a substantially arc-shaped discharge part is cut out so as to be substantially opposed to each other across the bearing hole 11a.

  A suction hole 21a having a substantially circular cross section that passes through the bottom wall of the pump body 11 and opens to the outside is formed at a substantially central position of the suction port 21. Thereby, the oil stored in the oil pan 01 of the engine is sucked into each pump chamber 20 in the suction area through the suction passage 03, the suction hole 21a and the suction port 21.

  The suction hole 21a is disposed and formed so as to face a suction side outer peripheral region including a spring accommodating chamber 28 described later of the cam ring 17.

  On the other hand, at the upper position of the discharge port 22 in FIG. 4, a discharge hole 22 a having a substantially circular cross section that passes through the bottom wall of the pump body 11 and opens to the outside is formed. Thereby, the oil in each pump chamber 20 in the discharge region pressurized by the pump action of the pump structure is supplied to the main oil gallery 05 through the discharge port 22, the discharge hole 22a, and the discharge passage 04. It is supplied to each sliding part in the engine, a variable valve operating device, and the like.

  As shown in FIG. 3, the cover member 12 has a substantially plate shape, and a position corresponding to the bearing hole 11 a of the pump body 11 on the outer side is formed in a cylindrical shape, and the substantially axial center of the cylindrical portion is formed. A bearing hole 12a that rotatably supports the other end of the drive shaft 14 is formed at a position. The cover member 12 is attached to the opening end surface of the pump body 11 by a plurality of bolts 26.

  The drive shaft 14 is configured to rotate the rotor 15 in the clockwise direction in FIG. 2 by a rotational force transmitted from a crankshaft (not shown) via a pulley or the like.

  As shown in FIG. 2, the rotor 15 has a plurality of slits 15a radially formed from the inner center side to the radially outer side, and the discharge port is provided at the inner base end of each slit 15a. A back pressure chamber 15b having a substantially circular cross section for introducing the oil discharged to 22 is formed.

  Each vane 16 is pushed outward by the centrifugal force accompanying the rotation of the rotor 15 and the back pressure of the back pressure chamber 15b. The inner surfaces of the adjacent vanes 16, 16, the outer peripheral surface of the rotor 15, the inner peripheral surface of the cam ring 17, the bottom surface 13 a of the pump housing chamber 13 of the pump body 11, and the cover member 12. The pump chamber 20 is liquid-tightly defined by the side surface.

  As shown in FIGS. 2 and 3, each ring member 19 has an outer peripheral surface in sliding contact with the inner end surface of the base end portion of each vane 16, and presses each vane 16 outward by centrifugal force. It has become. As a result, even when the engine speed is low and the centrifugal force or the back pressure in the back pressure chamber 15b is small, the outer end surface of each vane 16 is brought into contact with the inner peripheral surface of the cam ring 17. The liquid tightness of the pump chamber 20 can be secured.

  The cam ring 17 is formed integrally with a sintered metal in an annular shape, and as shown in FIG. 2, the cam ring 17 is fitted in the pivot pin 24 at a predetermined position on the outer peripheral portion to form an eccentric rocking fulcrum. A pivot portion 17a protrudes along the axial direction, and an arm portion 17b linked to the cam spring 18 is provided at a position opposite to the pivot portion 17a across the center of the cam ring 17 in the radial direction. Protruding along.

  A spring accommodating chamber 28 that communicates with the pump accommodating chamber 13 via a communication portion 27 is provided at a position opposite to the support hole 11 b of the pump body 11, and the spring accommodating chamber 28 includes the spring accommodating chamber 28. A distal end portion of the arm portion 17b and the cam spring 18 are accommodated.

  One end of the cam spring 18 is in elastic contact with the substantially arc-shaped support protrusion 17c protruding from the lower surface of the distal end of the arm portion 17b, and the other end is in elastic contact with the bottom surface of the spring accommodating chamber 28. The cam ring 17 is always urged through the arm portion 17b in the direction of increasing the eccentric amount (clockwise in FIG. 2) with a spring force (biasing force). As a result, in the operating state shown in FIG. 2, the cam ring 17 is pressed against the stopper surface 28 a formed on the lower surface of the upper wall of the spring accommodating chamber 28 by the spring force of the cam spring 18. In this state, the eccentric amount is held at the maximum position.

  In addition, a pair of first and second seals having a substantially triangular cross section having first and second seal surfaces facing the first and second seal sliding contact surfaces 11c and 11d are provided on the outer peripheral portion of the cam ring 17. The component parts 17d and 17e are formed to protrude. Each of the seal constituting portions 17d and 17e has first and second seal holding grooves each having a substantially arc concave cross section formed on each of the seal surfaces along the axial direction of the cam ring 17. A pair of seal members 30, 30 that are in sliding contact with the seal sliding contact surfaces 11c, 11d when the cam ring 17 is eccentrically swung are accommodated and held in the holding grooves.

  As shown in FIG. 4, the first and second seal surfaces are separated by a predetermined radius slightly smaller than the radii R1 and R2 from the center of the support hole 11b to the seal sliding contact surfaces 11c and 11d, respectively. It is formed in a circular arc shape, and is in sliding contact with each of the seal sliding contact surfaces 11c and 11d with a small clearance.

  As shown in FIG. 2, each of the seal members 30 and 30 is formed in a rectangular flat plate shape along the axial direction of the cam ring 17 by using, for example, a fluorine-based resin material having low friction characteristics, and the bottom of each seal holding groove. Are pressed against the seal sliding contact surfaces 11c and 11d by the elastic force of a rubber elastic member disposed on the surface. Thereby, the liquid tightness of each control oil chamber 31 and 32 mentioned later is always ensured.

  Further, first and second control oil chambers 31 and 32 are disposed on the pivot portion 17a side of the cam ring 17, that is, on the outer peripheral area on the pump discharge side, so as to sandwich the pivot portion 17a.

  Each of the control oil chambers 31 and 32 has an inner space having a substantially arc-shaped cross section defined by the inner peripheral surface of the pump body 11, the outer peripheral surface of the cam ring 17, and the seal members 30 and 30. Each part is defined by being further divided into two parts in the vertical direction in FIG.

  Of the control oil chambers 31, 32, the upper first control oil chamber 31 in FIG. 2 is the first supply hole 25 a through the first communication hole 25 a formed through the side of the pump body 11. The pump discharge pressure that is connected to the exhaust passage 7a and flows through the main oil gallery 05 is appropriately set via the first and second branch passages 3 and 4, the pilot valve 50, and the first communication hole 25a. It comes to be supplied.

  A first pressure receiving surface 33 for receiving the hydraulic pressure supplied into the first control oil chamber 31 is formed on the outer peripheral surface of the cam ring 17 facing the first control oil chamber 31. As a result, when hydraulic pressure is supplied into the first control oil chamber 31, the cam ring 17 is counteracted against the urging force of the cam spring 18 via the first pressure receiving surface 33, that is, the eccentricity. A swinging force in the direction of decreasing the amount is applied.

  On the other hand, the second control oil chamber 32 is connected to the second supply / discharge passage 7b through a second communication hole 25b formed in a side portion of the pump body 11 in parallel with the first communication hole 25a. The pump discharge pressure flowing in the main oil gallery 05 is the first and third branch passages 3 and 5, the electromagnetic switching valve 40, the intermediate passage 70, the pilot valve 50, and the first It is appropriately supplied via the communication hole 25a.

  A second pressure receiving surface 34 is formed on the outer peripheral surface of the cam ring 17 facing the second control oil chamber 32. As a result, when hydraulic pressure is supplied into the second control oil chamber 32, the direction of assisting the biasing force of the cam spring 18 via the second pressure receiving surface 34, that is, the direction of increasing the amount of eccentricity. The rocking force is applied.

  Here, as shown in FIG. 2, the pressure receiving area of the first pressure receiving surface 33 is set larger than the pressure receiving area of the second pressure receiving surface 34, and is applied based on the internal pressure of the first control oil chamber 31. The urging force and the urging force based on the internal pressure of the second control oil chamber 32 and the spring force of the cam spring 18 are balanced with a predetermined force relationship.

  Further, as described above, the electromagnetic switching valve 40 is interposed between the third branch passage 5 for supplying hydraulic pressure to the second control oil chamber 32 and the intermediate passage 70.

  As shown in FIGS. 1, 2 and 5, the electromagnetic switching valve 40 is a two-port three-position valve, and is transmitted in accordance with the operating state of the engine from a control unit (not shown) that controls the internal combustion engine. Based on the ON / OFF signal, the third branch passage 5 and the intermediate passage 70 are communicated, or the intermediate passage 70 and the drain passage 6 are communicated.

  That is, as shown in FIG. 5, the electromagnetic switching valve 40 is press-fitted into a valve housing hole 35a drilled from the outside of the cylinder block 35 to the connecting portion between the third branch passage 5 and the intermediate passage 70. The valve body 41 is fixed and has an operation hole 41a penetratingly formed along the inner axial direction, and is fitted and fixed to the tip of the valve body 41 (one end portion inside the cylinder block 35) of the operation hole 41a. A valve seat 42 formed in the center with a solenoid opening port 42a communicating with the downstream end of the third branch passage 5, and is provided inside and outside the valve seat 42 so as to be separable and openable to open and close the solenoid opening port 42a. And a solenoid unit 44 coupled to the base end portion (the other end portion) of the valve body 41. .

  In the valve body 41, a communication port 45 communicating with the intermediate passage 70 is formed in a radial direction at a side portion position of the ball valve body 43 which is a distal end side of the peripheral wall, while a proximal end portion of the peripheral wall is formed. On the side, a drain port 46 communicating with the drain passage 6 is formed to penetrate in the radial direction.

  The solenoid unit 44 accommodates and arranges an electromagnetic coil, a fixed plunger, a movable plunger, etc., not shown in the figure, and when a signal is emitted from the control unit to the electromagnetic coil, the movable plunger is moved in the axial direction accordingly. It is designed to move forward and backward.

  In addition, a return spring (not shown) is provided inside the solenoid unit 44 to constantly urge the movable plunger in the backward direction.

  Furthermore, one end of a cylindrical rod-shaped push rod 47 accommodated in the operation hole 41 a is coupled to the tip of the movable plunger, and the ball valve body 43 is connected to the valve via the push rod 47. It can be pressed in the direction of the sheet 42.

  A cylindrical passage 48 is formed between the outer peripheral surface of the push rod 47 and the inner peripheral surface of the central portion of the operating hole 41a so as to allow the communication port 45 and the drain port 46 to communicate appropriately.

  The control unit detects the current engine operating state from the oil temperature, water temperature, engine speed, load, etc. of the engine, and particularly when the engine speed is below a predetermined value, an ON signal (energization) is applied to the electromagnetic coil of the solenoid unit 44. When it is higher than a predetermined value, an off signal (non-energized) is output. However, even when the engine speed is below a predetermined value, an off signal is output to the electromagnetic coil when the engine is in a high load range.

  With this configuration, for example, when the engine speed is equal to or lower than a predetermined value, when an ON signal (energization) is output from the engine control unit to the electromagnetic coil of the solenoid unit 44, the movable plunger is moved to the return spring. As shown by the solid line in FIG. 5, the ball valve element 43 is pushed toward the valve seat 42 via the push rod 47 as it moves forward against the spring force. Then, the ball valve body 43 closes the solenoid opening port 42a and connects the communication port 45 with the passage 48 and the drain port 46, so that the hydraulic pressure in the second control oil chamber 32 is controlled by the pilot valve. 50 and the intermediate passage 70 can be discharged to the oil pan 01 through the communication port 45, the passage 48 and the drain port 46.

  On the other hand, for example, when the engine speed is higher than a predetermined value, when an off signal (non-energized) is output from the engine control unit to the electromagnetic coil of the solenoid unit 44, the movable plunger is moved to the spring of the return spring. By moving backward by force, the push of the ball valve element 43 by the push rod 47 is released. Then, the pump discharge pressure from the third branch passage 5 acts on the ball valve body 43 to urge the ball valve body 43 in the direction of the solenoid unit 44 as shown by a one-dot chain line in FIG. become. As a result, one end of the passage 48 is closed to block communication between the passage 48 and the drain port 46, the solenoid opening port 42a is opened, and the third branch passage 5 and the intermediate passage 70 are communicated. Therefore, the pump discharge pressure flowing through the main oil gallery 05 can be supplied to the second control oil chamber 32.

  Therefore, the oil pump 10 selects supply / discharge of the hydraulic pressure in the second control oil chamber 32 in accordance with the switching operation of the electromagnetic switching valve 40 based on the operating state of the engine. Along with this, the pump discharge pressure is controlled based on the hydraulic pressure in the first control oil chamber 31 supplied from the main oil gallery 05 and the biasing force of the cam spring 18. Thus, there are two types, a state in which control is performed to a predetermined low pressure P1 and a state in which control is performed to a predetermined high pressure P2 by controlling the amount of eccentricity of the cam ring 17 by adding the hydraulic pressure in the second control oil chamber 32 thereto The discharge pressure characteristic is obtained.

  The set load of the cam spring 18 is set based on these two types of discharge pressure characteristics.

  That is, when the hydraulic pressure is supplied only to the first control oil chamber 31 of the first and second control oil chambers 31 and 32, the cam spring 18 is operated with the hydraulic pressure lower than a predetermined low pressure P1. The set load is set so that the operation starts when the pressure becomes equal to or higher than the starting pressure P1 ′.

  When the same hydraulic pressure is supplied to the first and second control oil chambers 31 and 32, the cam spring 18 is based on the difference in urging force due to the area difference between the pressure receiving surfaces 33 and 34. In this case, when the hydraulic pressure supplied to the cam springs 31 and 32 becomes equal to or higher than the operation start pressure P2 ′ higher than the predetermined high pressure P2, the cam spring 18 generates a force in a direction against it. Set load is set to start operation.

  Note that the hydraulic pressure at which the cam spring 18 starts operating may fluctuate when the engine speed is high or when bubbles are included in the hydraulic oil, but the operation start pressure P2 ′ is The engine is set so as to be equal to or higher than the desired high pressure P2 in any operating condition of the engine.

  The oil pump 10 is provided with the pilot valve 50.

  As shown in FIGS. 2 and 6, the pilot valve 50 includes a cylindrical valve body 51 provided integrally with the outer wall of the pump body 11, and a sliding hole formed in the valve body 51. A spool valve 53 slidably accommodated in 52 and a control spring accommodating chamber 54 formed on the other axial end side of the valve body 51 are disposed in the upper direction in the drawing. A control spring 55 that is an urging member that urges the valve body 51, and a hook-like press-fit plug 56 that is press-fitted and fixed to the other end opening of the valve body 51 in a state where a spring load of the control spring 55 is applied. I have. The sliding hole 52 and the spool valve 53 (first and second land portions 63 and 64 described later) are slightly larger than the outer diameter with reference to the outer diameter of the control spring 55. Each diameter is set.

  In the valve body 51, an introduction port 57 having a smaller diameter than the sliding hole 52 is formed at an upper end opening located above the sliding hole 52 in FIG. The introduction port 57 communicates with the main oil gallery 05 through the first and second branch passages 3 and 4 and the second oil filter 2.

  Further, a stepped taper surface as a seating surface on which the spool valve 53 is seated by being biased upward by the spring force of the control spring 55 at the edge of the sliding hole 52 of the valve body 51 on the introduction port 57 side. 51a is formed.

  Furthermore, a first supply / discharge port 58, which is a first control port communicating with the first control oil chamber 31 via the first supply / discharge passage 7a, is formed on the peripheral wall of the valve body 51 where the sliding hole 52 faces. A second supply / discharge port 59, which is a second control port communicating with the second control oil chamber 32 via the second supply / discharge passage 7b, is formed through the radial supply direction. A drain port 60 communicating with the atmospheric pressure outside the pump is formed at a position below the port 59 along the radial direction.

  Further, a connection port connected to one end of the intermediate passage 70 between the first supply / exhaust port 58 and the second supply / exhaust port 59 on the peripheral wall and at a position opposite to both the ports 58, 59. 61 is formed so as to penetrate along the radial direction, and at the same position in the circumferential direction as the connection port 61 and below the drain port 60, the spool valve communicates with the atmospheric pressure. A back pressure port 62 for back pressure relief that ensures good slidability 53 is formed penetrating in the radial direction.

  The drain port 60 and the back pressure port 62 can communicate with the suction port 21 instead of the atmospheric pressure outside the pump.

  The spool valve 53 is integrally formed as a solid body, and has comparatively large-diameter cylindrical first and second land portions 63 and 64 provided on both ends in the axial direction, and the land portions 63 and 64. A comparatively small-diameter columnar small-diameter portion 65 that connects between them.

  The first and second land portions 63 and 64 are formed to have the same outer diameter, and slide on the inner peripheral surface of the sliding hole 52 through a minute gap.

  The first and second land portions 63 and 64 satisfy the communication or blocking conditions between the ports 58 to 61 in the first to fourth operating states of the oil pump 10 to be described later. The distance between the two 63 and 64 is set.

  That is, the distance L1 between the opposing side surfaces 63a, 64a of the first land portion 63 and the second land portion 64 is equal to the lower end edge 58a of the first supply / discharge port 58 in FIG. The distance between the lower end edge 61a of the connection port 61 in the drawing and the upper end edge 60a of the drain port 60 in the drawing is larger than the interval L2 between the upper and lower edges 59a of the two supply / discharge ports 59 in the drawing. It is set to be substantially equal to L3.

  The first land portion 63 is set so that its axial width is substantially the same as the hole diameter of the first supply / discharge port 58.

  Further, a cylindrical pressure receiving portion 66 having a slightly smaller diameter than the first land portion 63 is formed on the end face of the first land portion 63 on the introduction port 57 side. A flat pressure receiving surface 66 a that receives the pump discharge pressure introduced from the introduction port 57 into the sliding hole 52 is formed at the tip of the pressure receiving portion 66.

  In addition, a holding projection 67 that is a columnar convex portion having a smaller diameter than the second land portion 64 is provided on the end surface of the second land portion 64 on the press-fit plug 56 side.

  As shown in FIGS. 2 and 6, the small-diameter portion 65 allows oil to flow through an annular ring groove 68 formed on the outer periphery between the small-diameter portion 65 and the sliding hole 52.

  The control spring accommodating chamber 54 is cylindrically defined by the inner peripheral surface of the sliding hole 52, the end surface of the second land portion 64 of the spool valve 53 on the press-fit plug 56 side, and the inner end surface of the press-fit plug 56. It is made.

  The control spring 55 is set so that its spring force is smaller than the spring force of the cam spring 18.

  The control spring 55 has one end elastically contacting the end surface of the second land portion 64 on the press-fit plug 56 side, and the other end elastically contacting the inner end surface of the press-fit plug 56. Thus, the spool valve 53 is always urged toward the introduction port 57 side.

  Further, one end of the control spring 55 is held by the outer peripheral surface of the holding projection 67, and substantially the entire outer peripheral portion is held by the inner peripheral surface of the control spring accommodating chamber 54.

The spool valve 53 is moved downward or upward by the relative pressure between the pump discharge pressure received from the introduction port 57 and the spring force of the control spring 55 on the pressure receiving surface 66a, and the ports 57 to 61 are moved. It opens and closes (communicates) as appropriate. The opening / closing operation of the ports 57 to 61 by the operation of the spool valve 53 will be specifically described in the section of the operation of the present embodiment below.
[Operation of this embodiment]
Hereinafter, the operation of the variable displacement oil pump according to the present embodiment will be described with reference to FIGS. 2 and 7 to 10.

  First, when the engine is in a low-rotation operating state from the start, the oil pump 10 enters the first operating state shown in FIG.

  In this first operating state, the electromagnetic switching valve 40 is energized when the internal electromagnetic coil receives an ON signal from the control unit, and the ball valve body 43 is moved through the movable plunger and the push rod 47. By pushing up toward the valve seat 42, the solenoid opening port 42a of the valve seat 42 is closed, while the communication port 45 and the drain port 46 are connected.

  Further, since the pilot valve 50 has a low engine speed and low oil pressure, and the pump discharge pressure (pilot pressure) acting on the pressure receiving surface 66a is also small, the spool valve 53 moves toward the press-fit plug 56. In other words, the state where the tip edge of the pressure receiving portion 66 is seated on the stepped tapered surface 51a is maintained.

  Thereby, the pilot valve 50 is in a state where the first and second supply / discharge ports 58 and 59 and the connection port 61 are communicated with each other via the annular groove 68 on the outer periphery of the small diameter portion 65.

  Accordingly, in the first operating state, the first control oil chamber 31 and the second control oil chamber 32 are both in communication with the drain port 46, so that hydraulic pressure is not introduced into the both 31 and 32. The eccentric amount control of the cam ring 17 is performed.

  That is, the cam ring 17 does not depend on the hydraulic pressure in the first and second control oil chambers 31 and 32, and only the spring force of the cam spring 18 is used in the clockwise direction in FIG. The maximum eccentric state in contact with the surface 28a is maintained.

  As a result, in the first operating state, the pump discharge pressure of the oil pump 10 increases substantially in proportion to the increase in the engine speed, as shown in the rotation region a of FIG.

  Thereafter, when the rotational speed of the engine exceeds the rotation region a and the pump discharge pressure in the main oil gallery 05 reaches a low pressure P1 shown in FIG. 10, the oil pump 10 is connected to the second pump shown in FIG. Transition to the operating state.

  Even in the second operating state, the electromagnetic switching valve 40 is maintained in the energized state, as in the first operating state.

  The pilot valve 50 communicates the second supply / exhaust port 59 and the connection port 61 through the annular groove 68 in the same manner as in the first operating state, so that the second control oil chamber 32 is The state is communicated with the drain port 46.

  Further, when the pilot valve 50 receives a pump discharge pressure higher than the low pressure P1 on the pressure receiving surface 66a of the spool valve 53, the pilot valve 50 moves backward while resisting the spring force of the control spring 55. The introduction port 57 and the first supply / exhaust port 58 are communicated with each other in an orifice state in which the opening area is reduced by the one land portion 63.

  At this time, the hydraulic pressure supplied into the first control oil chamber 31 is P1 ′ which is reduced from the pump discharge pressure by passing through the orifice portion, but the set load of the cam spring 18 is also Since the hydraulic pressure is supplied only to the first control oil chamber among the first and second control oil chambers 31 and 32, it is set to operate at the operation start pressure P1 ′. The pump discharge pressure can be controlled without being affected by the reduced pressure.

  As a result, the first control oil chamber 31 is supplied with a reduced hydraulic pressure through the orifice portion that expands according to the pump discharge pressure, and the cam ring 17 is camped based on the hydraulic pressure. While urging the spring force of the spring 18 to bias the eccentric amount, the pump discharge amount is reduced and the pump discharge pressure is reduced.

  On the other hand, when the pump discharge pressure received by the pressure receiving surface 66a is lower than the low pressure P1, the pilot valve 50 moves the spool valve 53 toward the introduction port 57 by the spring force of the control spring 55. As in the first operating state, the introduction port 57 and the first supply / discharge port 58 are blocked by the first land portion 63 and the first supply / discharge port 58 and the drain port 46 are communicated with each other. Let

  As a result, the hydraulic pressure in the first control oil chamber 31 is reduced, and the eccentric amount of the cam ring 17 increases accordingly. As a result, the pump discharge amount increases and the pump discharge pressure increases.

  Therefore, in the second operating state, the pilot valve 50 introduces oil into the first control oil chamber 31 and adjusts the pressure as the pump discharge pressure of the oil pump 10 increases. While the pump discharge pressure is reduced, the pump discharge pressure is improved by adjusting the pressure by deriving oil from the first control oil chamber 31 when the pump discharge pressure is lowered, and the pressure is adjusted to the low pressure P1. Yes.

  In the present embodiment, since the hole diameter of the first supply / discharge port 58 and the axial width of the first land portion 63 that closes the first supply / discharge port 58 are substantially the same length, the first control The oil supply / discharge of the oil chamber 31 can be switched and controlled only by a minute movement of the spool valve 53. For this reason, since the influence of the spring constant of the control spring 55 hardly affects the discharge pressure control, the pump discharge pressure can be accurately controlled to the low pressure P1.

  As a result, in the second operating state, the pump discharge pressure of the oil pump 10 is maintained substantially at the low pressure P1 regardless of the increase in the engine speed, as shown in the rotation region b of FIG. It becomes.

  Next, when the engine speed further increases and the load and hydraulic pressure increase, and when the engine enters a high load operation state in which the operation of an oil jet for injecting oil to the piston is required, the oil pump 10 performs the third operation shown in FIG. It becomes the operation state.

  In this third operating state, the electromagnetic switching valve 40 is in a non-energized state when the internal electromagnetic coil receives an OFF signal from the control unit, and accordingly, the ball valve element 43 moves toward the valve seat 42. Since the urging force is released, the solenoid opening port 42a is opened. When the solenoid opening port 42a is opened, the ball valve body 43 is biased toward the solenoid unit 44 by the pump discharge pressure supplied through the solenoid opening port 42a. Is closed, and the communication between the communication port 45 and the drain port 46 is blocked.

  The pilot valve 50 makes the introduction port 57 and the first supply / discharge port 58 communicate with each other, and makes the second supply / discharge port 59 and the connection port 61 communicate with each other, as in the second operation state. ing. Further, the second land portion 64 blocks the second supply / exhaust port 59 and the drain port 60.

  Therefore, in the third operating state, since hydraulic pressure is introduced into both the first control oil chamber 31 and the second control oil chamber 32, the cam ring 17 is coupled with the spring force of the cam spring 18 and the first control oil chamber 32. 2 Moves again clockwise in FIG. 8 by the hydraulic pressure of the control oil chamber 32 and returns to the maximum eccentric state again.

  As a result, in the third operating state, the pump discharge pressure of the oil pump 10 increases again almost in proportion to the increase in the engine speed, as shown in the rotation region c of FIG.

  Thereafter, when the engine speed exceeds the rotation region c, and the discharge pressure of the main oil gallery 05 reaches a high pressure P2 shown in FIG. 10, the oil pump 10 performs the fourth operation shown in FIG. Transition to the state.

  Even in the fourth operating state, the electromagnetic switching valve 40 is maintained in a non-energized state, as in the third operating state.

  The pilot valve 50 allows the introduction port 57 and the first supply / exhaust port 58 to communicate with each other as in the third operating state.

  Further, when the pilot valve 50 receives a pump discharge pressure higher than the high pressure P2 on the pressure receiving surface 66a, the pilot valve 50 moves backward against the spring force of the control spring 55, whereby the second supply / discharge port 59 is provided. And the drain port 60 are communicated with each other.

  At this time, a hydraulic pressure equivalent to the pump discharge pressure is supplied to the first control oil chamber 31, while the hydraulic pressure introduced from the second control oil chamber 32 to the third operating state is the drain port. It is in a state of being gradually discharged through 60.

  For this reason, the force in the direction against the cam spring 18 is not only the difference in urging force due to the difference in area between the pressure receiving surfaces 33 and 34 but also in the first and second control oil chambers 31 and 32. Since it is also affected by the hydraulic pressure difference, as a result, the state is the same as when P2 ′ pressurized to the pump discharge pressure is supplied to both 31 and 32.

  On the other hand, the set load of the cam spring 18 is set to operate at the operation start pressure P2 ′ when the hydraulic pressure is supplied to both the first and second control oil chambers 31 and 32. Therefore, the pump discharge pressure can be controlled without being affected by the pressure reduction caused by the discharge of the second control oil chamber 32.

  Thereby, the second control oil chamber 32 is appropriately depressurized according to the pump discharge pressure, and based on this, the cam ring 17 is moved in the direction of decreasing the eccentric amount, thereby reducing the pump discharge amount. Reduce the pump discharge pressure.

  On the other hand, when the pump discharge pressure received by the pressure receiving surface 66a is lower than the high pressure P2, the pilot valve 50 moves the spool valve 53 toward the introduction port 57 by the spring force of the control spring 55. As in the third operating state, the second land portion 64 blocks the second supply / exhaust port 59 and the drain port 60.

  As a result, the hydraulic pressure in the second control oil chamber 32 is pressurized, and the eccentric amount of the cam ring 17 is increased accordingly, so that the pump discharge amount is increased and the pump discharge pressure is increased.

  Therefore, in the fourth operating state, the pilot valve 50 allows the oil in the second control oil chamber 32 to be depressurized and adjusted as the pump discharge pressure of the oil pump 10 increases. On the other hand, when the pump discharge pressure is lowered, the pump discharge pressure is improved by adjusting the pressure by introducing oil into the second control oil chamber 32 and adjusting the pressure to the high pressure P2. ing.

  In the present embodiment, the distance L1 between the side surfaces 63a, 64a facing each other in the axial direction of the first and second land portions 63, 64 is substantially equal to the distance L3 between the drain port 60 and the connection port 61. Therefore, the oil supply / discharge of the second control oil chamber 32 can be switched and controlled only by a minute movement of the spool valve 53. For this reason, since the influence of the spring constant of the control spring 55 hardly affects the discharge pressure control, the pump discharge pressure can be accurately controlled to the high pressure P2.

  As a result, in the fourth operating state, the pump discharge pressure of the oil pump 10 is maintained substantially at the high pressure P2 regardless of the increase in the engine speed, as shown in the rotation region d of FIG. It becomes.

  Thus, in this embodiment, by controlling the operation of the pilot valve 50 via the electromagnetic switching valve 40, the pump discharge pressure can be controlled to the two-stage characteristic of the low pressure P1 and the high pressure P2.

  In this embodiment, the pilot valve 50 is configured so that oil does not flow through the control spring accommodating chamber 54 in all of the first to fourth operating states described above.

  That is, when the oil is discharged from the first and second control oil chambers 31 and 32 based on the eccentricity control of the cam ring 17, the annular groove 68 formed at the center position of the spool valve 53. Then, the oil pump 10 is discharged to the outside.

  For this reason, as in the prior art, the hydraulic pressure of the oil discharged from the first and second control oil chambers 31 and 32 flows into the control spring accommodation chamber 54, and the back pressure enters the control spring accommodation chamber 54. The problem that the position control of the spool valve 53 due to the pump discharge pressure (pilot pressure) applied to the pressure receiving surface 66a and the spring force of the control spring 55 becomes unstable due to the back pressure can be avoided. .

  Therefore, according to the present embodiment, by improving the stability of the position control of the spool valve 53, the control accuracy of the pump discharge pressure with respect to the set hydraulic characteristics can be improved. This effect is particularly effective in the fourth operating state in which relatively high-pressure oil is discharged from the second control oil chamber 32.

  By the way, as a spool valve applied to the pilot valve 50, a cylinder with a lid having a pressure receiving wall at one end as in the conventional variable displacement oil pump is generally used.

  However, the shape of such a covered cylindrical spool valve is complicated because it is necessary to form a passage through which oil flows on the peripheral wall.

  In addition, the covered cylindrical spool valve must be formed with a valve diameter larger than the outer diameter of the control spring 55 in order to accommodate one end side of the control spring 55 inside. Since the diameter of the sliding hole 52 is increased in accordance with the valve diameter, the pilot valve 50 is increased in size.

  Further, since the outer diameter of the control spring 55 inevitably becomes smaller than the diameter of the sliding hole 52, the other end side of the control spring 55 is in an unstable state in which it floats in the air. For this reason, as the plug for sealing the sliding hole 52, a screw plug or the like having a groove for holding the other end of the control spring 55 is used to hold the other end of the control spring 55. However, this may also lead to an increase in the size of the pilot valve 50.

  On the other hand, in the present embodiment, the spool valve 53 is formed in a solid shape, and oil flows through the annular groove 68 on the outer periphery of the small diameter portion 65, so that the shape is relatively simple. .

  In addition, since the control spring 55 is elastically supported by the end face of the second land portion 64 on the press-fit plug 56 side, the valve diameter of the spool valve 53 (the outer diameter of each land portion 63, 64). ) Can be set to substantially the same diameter as the outer diameter of the control spring 55, and accordingly, the hole diameter of the sliding hole 52 can be made substantially the same as the outer diameter of the control spring 55. As a result, the pilot valve 50 can be reduced in size and the control spring 55 is guided by the inner peripheral surface of the sliding hole 52, so that the pump discharge pressure (pilot) acting on the pressure receiving surface 66a can be reduced. The spring force can be accurately exhibited with respect to (pressure).

  Further, since the control spring 55 is held by the inner peripheral surface of the control spring accommodating chamber 54 (the inner peripheral wall of the valve body 51), a simple shape can be used without using a screw plug or the like as described above. It is possible to support the sealing of the sliding hole 52 and the other end of the control spring 55 only by press-fitting the press-fit plug 56.

  In the present embodiment, since the holding projection 67 is formed to project from the end face of the second land portion 64 on the press-fit plug 56 side, one end of the control spring 55 is connected to the inside of the valve body 51. Since it is clamped between the peripheral wall and the outer peripheral surface of the holding projection 67, the holding performance of the control spring 55 is further improved.

  Furthermore, in the present embodiment, the electromagnetic switching valve 40 is energized when the oil can be discharged from the second control oil chamber 32, that is, in the first and second operating states. When the oil can be introduced into the second control oil chamber 32, that is, in the third and fourth operating states, the non-energized state is established.

Thereby, for example, when the electromagnetic coil of the electromagnetic switching valve 40 or a harness outside the figure is disconnected, the high pressure characteristic remains even if the low pressure characteristic is lost, so that the operation can be continued safely. .
[Second Embodiment]
FIG. 11 shows a second embodiment of the present invention. The basic configuration is the same as that of the first embodiment, but the holding structure of the control spring 55 of the pilot valve 50 is changed.

  The second land portion 64 of the spool valve 53 in this embodiment is formed so that the width in the axial direction is longer than that in the first embodiment. In the second land portion 64, the holding projection 67 is abolished from the end surface on the control spring 55 side, and a holding groove portion 71, which is a cylindrical recess, is provided in a substantially central position of the end surface. ing. The holding groove portion 71 is formed to have a smaller diameter than the outer diameter of the second land portion 64 and slightly larger than the outer diameter of the control spring 55, and the groove bottom is one end portion of the control spring 55. And one end of the control spring 55 is held by the peripheral wall.

  Further, the press-fit plug 56 is abolished on the other end portion side of the control spring 55 of the valve body 51, and a screw plug 72, which is a cylindrical member with a lid, is screwed and fixed. In the screw plug 72, the inner wall of the lid 72a is in elastic contact with the other end of the control spring 55, and the other end of the control spring 55 is held by the inner peripheral wall of the cylindrical portion 72b. .

  Therefore, also in this embodiment, as in the first embodiment, the oil discharged from the first and second control oil chambers 31 and 32 does not flow through the control spring accommodating chamber 54. It is possible to improve the stability of the position control of the valve 53 and improve the control accuracy of the pump discharge pressure with respect to the set hydraulic characteristics.

  Further, since both axial end portions of the control spring 55 can be held in a stable state by the holding groove portion 71 of the second land portion 64 and the inner wall of the screw plug 72, the pump discharge pressure acting on the pressure receiving surface 66a. The spring force can be exhibited accurately with respect to (pilot pressure).

  FIG. 12 is a modification of the second embodiment, in which the small-diameter portion 65 of the spool valve 53 is formed to have a larger diameter compared to the second embodiment, and the holding groove portion 71 is The second land portion 64 is recessed from the end surface on the control spring 55 side to the inside of the small diameter portion 65. Therefore, also in this case, it is possible to obtain the same effect as that of the second embodiment.

  The present invention is not limited to the configuration of each of the embodiments described above, and the configuration can be changed without departing from the spirit of the invention.

  For example, in the present embodiment, the switching times of the respective ports by the first land portion 63 and the second land portion 64 of the spool valve 53 are set at the same time. There may be.

  Moreover, the characteristics of the opening area may be changed by chamfering or rounding the end edges in the axial direction of the first and second land parts 63 and 64, and these may be adjusted according to the characteristics of the mounted engine. Is done.

  In the present embodiment, in consideration of fail-safety when the electromagnetic switching valve 40 fails, the non-energized state is set in the third and fourth operating states (during high engine speed). However, it is also possible to reversely set energization and deenergization in consideration of power saving and the like.

  Further, the energization / non-energization timing of the electromagnetic switching valve 40 can be changed as appropriate according to various configurations. For example, switching to the non-energized state can be performed at a higher engine speed than in the above embodiments. By performing at this point, the oil pump 10 can be directly switched from the second operating state to the fourth operating state.

  As the variable displacement oil pump based on the embodiment described above, for example, the following modes can be considered.

  In one aspect, the variable displacement oil pump is a pump structure that changes the volume of a plurality of pump chambers by being rotationally driven by an internal combustion engine, and discharges hydraulic oil sucked from the suction portion from the discharge portion. A movable member that changes the volume change amount of the plurality of pump chambers by moving, and the movable member is provided in a state in which a set load is applied and the volume change amount of the plurality of pump chambers increases. A first control oil chamber that applies a force in a direction to reduce the volume change amount of the plurality of pump chambers to the movable member when the hydraulic oil is supplied; Is supplied, a second control oil chamber that acts on the movable member in a direction that increases the volume change amount of the plurality of pump chambers, and a state in which the hydraulic oil is discharged from the second control oil chamber. And a state in which hydraulic oil is introduced into the second control oil chamber, and a switching mechanism formed to be switchable, and when the switching mechanism is in a state of discharging hydraulic oil from the second control oil chamber, A state in which the hydraulic oil in the first control oil chamber is discharged and a state in which the hydraulic oil having a pressure lower than the discharge pressure from the discharge portion is introduced into the first control oil chamber, and the discharge pressure increases. The hydraulic oil is introduced into the first control oil chamber according to the above, the pressure is adjusted in the first control oil chamber, and the switching mechanism is in a state of introducing the hydraulic oil into the second control oil chamber. A state in which the hydraulic oil reduced in pressure than the discharge pressure from the discharge unit is introduced into the second control oil chamber, and the introduction of the hydraulic oil into the second control oil chamber via the switching mechanism is shut off, The hydraulic oil in the second control oil chamber is discharged and the discharge pressure is high. And a control mechanism that discharges the hydraulic oil in the second control oil chamber and adjusts the pressure in the second control oil chamber to a reduced pressure. The control mechanism includes a hydraulic pressure by the hydraulic oil and a biasing member. While being controlled by the urging force, the hydraulic oil is not guided to a portion where the urging member is disposed.

  In a preferred aspect of the variable displacement oil pump, the control mechanism includes an introduction port for introducing hydraulic pressure of hydraulic oil discharged from the discharge portion, a first control port communicating with the first control oil chamber, A valve body having a second control port communicating with the second control oil chamber; a connection port connected to the switching mechanism; and a drain port communicating with the low pressure portion; and sliding on one end side in the axial direction of the valve body The communication state of the introduction port and the connection port with respect to the first control oil chamber and the communication state of the connection port and the drain port with respect to the second control oil chamber are switched according to the sliding position in the axial direction. The biasing valve is housed and disposed on the other axial end side of the spool valve and the valve body, and biases the spool valve toward one axial end side by a biasing force smaller than that of the biasing mechanism. Having a control spring which is wood, a.

  In another preferred aspect, in any one of the aspects of the variable displacement oil pump, the spool valve has a large-diameter land portion that slides with the valve body at both axial end portions, and each of the land portions. A small-diameter portion is formed between the first control oil chamber and the connection port and the drain with respect to the second control oil chamber. The port is formed so as to communicate appropriately.

  In still another preferred aspect, in any one of the aspects of the variable displacement oil pump, the introduction port is provided at one axial end of the valve body, and the spool valve is disposed at an axial end on the introduction port side. A pressure receiving surface on which hydraulic pressure of the hydraulic oil acts is formed at the portion.

  In still another preferred aspect, in any of the aspects of the variable displacement oil pump, the first and second control ports and the drain port are respectively formed through the peripheral wall of the valve body.

  In still another preferred embodiment, in any of the embodiments of the variable displacement oil pump, the spool valve is formed solid.

  In still another preferred aspect, in any one of the aspects of the variable displacement oil pump, a cylindrical convex portion having a smaller diameter than the land portion is formed to protrude from an end surface of the land portion on the control spring side, One end side of the control spring is held by the convex portion.

  In still another preferred aspect, in any of the aspects of the variable displacement oil pump, the control spring is supported by an inner peripheral wall of the valve body.

  In another preferred embodiment, in any one of the embodiments of the variable displacement oil pump, a cylindrical recess having a smaller diameter than the land portion is formed on the end surface on the control spring side of the land portion toward the introduction port side. The one end side of the said control spring is hold | maintained by this recessed part.

  In still another preferred aspect, in any one of the aspects of the variable displacement oil pump, a cylindrical member with a lid is disposed at the control spring side end of the valve body, and the other end of the control spring. The side is held by the inner wall surface of the cylindrical member.

  In still another preferred aspect, in any of the aspects of the variable displacement oil pump, when the hydraulic oil is discharged from the first and second control oil chambers at the same time, the hydraulic oil is supplied to the small diameter portion. After passing through the outer periphery, it is discharged via the switching mechanism.

  In still another preferred aspect, in any one of the aspects of the variable displacement oil pump, the switching mechanism is an electromagnetic control valve that is electrically switched.

  In still another preferred aspect, in any one of the aspects of the variable displacement oil pump, the electromagnetic control valve is in a non-energized state when operating oil is guided to the second control chamber, and the second control oil When operating oil is discharged from the chamber, it is energized.

  In still another preferred aspect, in any one of the aspects of the variable displacement oil pump, the electromagnetic control valve performs switching of supply and discharge of the hydraulic oil to and from the second control oil chamber by a ball valve.

  In still another preferred aspect, in any one of the aspects of the variable displacement oil pump, the hydraulic oil discharged from the discharge portion is used as a lubricating oil for lubricating a constituent member included in the internal combustion engine.

  In still another preferred aspect, in any one of the aspects of the variable displacement oil pump, the hydraulic oil discharged from the discharge unit supplies the hydraulic oil to a drive source of a variable valve operating device and a piston of the internal combustion engine. Used for oil jets.

  In another aspect, the variable displacement oil pump includes a rotor that is rotationally driven by an internal combustion engine, a plurality of vanes that are provided in an outer periphery of the rotor, and the rotor and the vanes on an inner peripheral side. A plurality of cam chambers that separate the plurality of pump chambers while being housed and change the amount of eccentricity with respect to the axis of the rotor by moving to change the volume change amount of the plurality of pump chambers; and Of these, a suction portion that opens to a suction region that increases in volume as the rotor rotates, a discharge portion that opens to a discharge region whose volume decreases as the rotor rotates among the plurality of pump chambers, and a set load is applied And a biasing mechanism that biases the cam ring in a direction in which the amount of eccentricity increases, and a direction in which the amount of eccentricity decreases by supplying hydraulic oil. A first control oil chamber for applying a force to the cam ring; a second control oil chamber for applying a force in a direction in which the eccentric amount increases by supplying hydraulic oil; and the second control oil. A switching mechanism configured to be able to switch between a state in which the hydraulic oil is discharged from the chamber and a state in which the hydraulic oil is introduced into the second control oil chamber, and the switching mechanism discharges the hydraulic oil from the second control oil chamber A state in which the hydraulic oil in the first control oil chamber is discharged, and a state in which the hydraulic oil having a pressure reduced from the discharge pressure from the discharge portion is introduced into the first control oil chamber. As the discharge pressure increases, hydraulic oil is introduced into the first control oil chamber to adjust the pressure in the first control oil chamber, and the switching mechanism supplies the hydraulic oil to the second control oil chamber. When in the state of introduction, the second control oil chamber The state of introducing the hydraulic oil whose pressure is lower than the discharge pressure from the discharge unit and the introduction of the hydraulic oil to the second control oil chamber via the switching mechanism are blocked, and the hydraulic oil in the second control oil chamber is And a control mechanism that discharges the hydraulic oil in the second control oil chamber as the discharge pressure increases, and adjusts the pressure in the second control oil chamber to be reduced. The hydraulic oil is controlled by the hydraulic pressure by the hydraulic oil and the biasing force by the biasing member, and the hydraulic oil is not guided to the portion where the biasing member is disposed.

  In a preferred aspect of the variable displacement oil pump, the first and second control oil chambers are provided on an outer peripheral side of the cam ring and defined by a swing fulcrum provided on the outer peripheral side of the cam ring. ing.

Claims (18)

A pump structure that discharges hydraulic fluid sucked from the suction portion from the discharge portion, by the volume of the plurality of pump chambers being changed by being rotationally driven by the internal combustion engine;
A movable member that changes a volume change amount of the plurality of pump chambers by moving;
An urging mechanism that is provided in a state in which a set load is applied and urges the movable member in a direction in which a volume change amount of the plurality of pump chambers increases;
A first control oil chamber that applies a force to the movable member in a direction to reduce a volume change amount of the plurality of pump chambers by supplying hydraulic oil;
A second control oil chamber that applies a force to the movable member in a direction to increase a volume change amount of the plurality of pump chambers by supplying hydraulic oil;
A switching mechanism formed to be switchable between a state in which the hydraulic oil is discharged from the second control oil chamber and a state in which the hydraulic oil is introduced into the second control oil chamber;
When the switching mechanism is in a state of discharging the hydraulic oil from the second control oil chamber, the state of discharging the hydraulic oil in the first control oil chamber and the discharge from the discharge unit to the first control oil chamber Taking a state of introducing hydraulic oil whose pressure is lower than the pressure, introducing hydraulic oil into the first control oil chamber as the discharge pressure increases, and adjusting the pressure in the first control oil chamber; And when the switching mechanism is in a state of introducing hydraulic oil into the second control oil chamber, a state of introducing hydraulic oil having a pressure lower than the discharge pressure from the discharge portion into the second control oil chamber; The introduction of hydraulic oil into the second control oil chamber via the switching mechanism is shut off, the hydraulic oil in the second control oil chamber is discharged, and the second control is increased as the discharge pressure increases. The hydraulic oil in the oil chamber is discharged and the pressure in the second control oil chamber is reduced. A control mechanism to adjust;
With
The control mechanism is controlled by a hydraulic pressure by hydraulic oil and a biasing force by a biasing member, and has a configuration in which the hydraulic oil is not guided to a portion where the biasing member is disposed. Shape oil pump. The variable displacement oil pump according to claim 1, wherein
The control mechanism is
An introduction port for introducing hydraulic pressure of hydraulic oil discharged from the discharge section, a first control port communicating with the first control oil chamber, a second control port communicating with the second control oil chamber, and the switching A valve body having a connection port connected to the mechanism and a drain port communicating with the low pressure portion;
The valve body is slidably accommodated at one axial end of the valve body, and the communication state of the introduction port and the connection port with respect to the first control oil chamber according to the axial sliding position, and the second control oil chamber A spool valve that switches the communication state of the connection port and the drain port;
A control spring that is an urging member that is accommodated and disposed on the other axial end side of the valve body, and that urges the spool valve toward one axial end side by an urging force smaller than the urging mechanism;
A variable displacement oil pump characterized by comprising: The variable displacement oil pump according to claim 2,
The spool valve has a large-diameter land portion that slides with the valve body at both axial ends, and a small-diameter portion is formed between the land portions,
The connection port is appropriately communicated with the first control oil chamber through the outer periphery of the small diameter portion, and the connection port and the drain port are appropriately communicated with the second control oil chamber. Variable displacement oil pump. In the variable displacement oil pump according to claim 3,
The introduction port is provided at one axial end of the valve body,
The variable displacement oil pump according to claim 1, wherein the spool valve has a pressure receiving surface on which an oil pressure of hydraulic oil acts at an axial end on the introduction port side. The variable displacement oil pump according to claim 4,
The variable displacement oil pump according to claim 1, wherein the first and second control ports and the drain port are respectively formed through the peripheral wall of the valve body. In the variable displacement oil pump according to claim 5,
2. The variable displacement oil pump according to claim 1, wherein the spool valve is solid. The variable displacement oil pump according to claim 6,
On the end surface of the land portion on the control spring side, a cylindrical convex portion having a smaller diameter than the land portion is formed to protrude,
One end side of the control spring is held by the convex portion. The variable displacement oil pump according to claim 7,
The variable displacement oil pump, wherein the control spring is supported on an inner peripheral wall of the valve body. In the variable displacement oil pump according to claim 5,
On the end face of the land portion on the control spring side, a cylindrical concave portion having a smaller diameter than the land portion is provided in the direction toward the introduction port,
One end side of the control spring is held by the concave portion. The variable displacement oil pump according to claim 9,
At the control spring side end of the valve body, a covered cylindrical tubular member is disposed,
2. The variable displacement oil pump according to claim 1, wherein the other end side of the control spring is held by an inner wall surface of the cylindrical member. In the variable displacement oil pump according to claim 3,
When hydraulic oil is discharged from the first and second control oil chambers at the same time, the hydraulic oil is discharged via the switching mechanism after passing through the outer periphery of the small diameter portion. Variable displacement oil pump. The variable displacement oil pump according to claim 1, wherein
The variable displacement oil pump according to claim 1, wherein the switching mechanism is an electromagnetic control valve that is electrically controlled to be switched. The variable displacement oil pump according to claim 12,
The electromagnetic control valve is in a non-energized state when hydraulic oil is introduced into the second control chamber, and is in an energized state when hydraulic oil is discharged from the second control oil chamber. Capacity type oil pump. The variable displacement oil pump according to claim 13,
A variable displacement oil pump, wherein the electromagnetic control valve performs switching of supply and discharge of hydraulic oil to and from the second control oil chamber by a ball valve. The variable displacement oil pump according to claim 1, wherein
The variable displacement oil pump according to claim 1, wherein the hydraulic oil discharged from the discharge portion is used as a lubricating oil for lubricating a constituent member included in the internal combustion engine. The variable displacement oil pump according to claim 15,
The variable displacement oil pump is characterized in that the hydraulic oil discharged from the discharge unit is also used for an oil jet that supplies hydraulic oil to a drive source of a variable valve device and a piston of the internal combustion engine. A rotor driven to rotate by an internal combustion engine;
A plurality of vanes provided on the outer periphery of the rotor so as to be freely movable; and
A plurality of pump chambers are separated while accommodating the rotor and the vanes on the inner peripheral side, and the amount of eccentricity with respect to the shaft center of the rotor is changed by moving to change the volume change amount of the plurality of pump chambers Cam ring to make,
A suction portion that opens to a suction region whose volume increases with rotation of the rotor among the plurality of pump chambers;
A discharge portion that opens to a discharge region whose volume decreases with rotation of the rotor among the plurality of pump chambers;
An urging mechanism that is provided in a state where a set load is applied and urges the cam ring in a direction in which the amount of eccentricity increases;
A first control oil chamber that applies a force in a direction in which the amount of eccentricity is reduced to the cam ring by supplying hydraulic oil;
A second control oil chamber that applies a force in a direction in which the amount of eccentricity increases to the cam ring by supplying hydraulic oil;
A switching mechanism formed so as to be switchable between a state in which the hydraulic oil is discharged from the second control oil chamber and a state in which the hydraulic oil is introduced into the second control oil chamber;
When the switching mechanism is in a state of discharging the hydraulic oil from the second control oil chamber, the state of discharging the hydraulic oil in the first control oil chamber and the discharge from the discharge unit to the first control oil chamber Taking a state of introducing hydraulic oil whose pressure is lower than the pressure, introducing hydraulic oil into the first control oil chamber as the discharge pressure increases, and adjusting the pressure in the first control oil chamber; And when the switching mechanism is in a state of introducing hydraulic oil into the second control oil chamber, a state of introducing hydraulic oil having a pressure lower than the discharge pressure from the discharge portion into the second control oil chamber; The introduction of hydraulic oil into the second control oil chamber via the switching mechanism is shut off, the hydraulic oil in the second control oil chamber is discharged, and the second control is increased as the discharge pressure increases. The hydraulic oil in the oil chamber is discharged and the pressure in the second control oil chamber is reduced. A control mechanism to adjust;
With
The control mechanism is controlled by a hydraulic pressure by hydraulic oil and a biasing force by a biasing member, and has a configuration in which the hydraulic oil is not guided to a portion where the biasing member is disposed. Shape oil pump. The variable displacement oil pump according to claim 17,
The first and second control oil chambers are provided on the outer peripheral side of the cam ring and are defined by a swing fulcrum provided on the outer peripheral side of the cam ring. pump.

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