JP2016098767A - Variable capacity pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a variable capacity pump controlling the capacity of a pump part with good responsiveness.SOLUTION: A pump part P changing a discharge amount is constituted by displacement of an operation body 22 stored in a pressure chamber PS. A variable capacity pump includes a pressure control valve CV supplying part of fluid discharged from the pump part P to the pressure chamber PS through a control flow passage 7, and a discharge control valve DV controlling a flow rate of a drain flow passage 8 to which fluid is discharged from the pressure chamber PS. The discharge control valve DV limits a flow rate of fluid at the time of pressure rise in the pressure chamber PS, and performs operation of discharging fluid without limitation according to pressure deterioration in the pressure chamber PS.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a variable displacement pump that changes the amount of fluid discharged by operating an operating body in accordance with fluid pressure.

  As a variable displacement pump configured as described above, Patent Document 1 discloses an outer toothed inner rotor, an inner toothed outer rotor, and an actuator (adjusting ring in the document) that supports the outer rotor in a displaceable manner. The technology of the oil pump built in is shown.

  In Patent Document 1, a trochoid pump portion is formed by an inner rotor and an outer rotor, and an arm portion is integrally formed as a working body in a main body portion, and this is accommodated in a control space. With the operation of the arm portion, the amount of oil discharged from the pump portion can be adjusted. For this purpose, an urging force is applied to the arm part from the spring, and the oil pressure from the pump part is applied to the arm part in a direction against the urging force of the spring.

  In this patent document 1, the oil pressure of a pump part is made to act on control space, and the oil pressure which acts on an arm part is easily formed with a control valve by forming the oil relief hole which discharges the oil of control space. It is configured to be adjustable.

JP 2014-139420 A

  In the configuration of Patent Document 1, the oil pressure acting on the arm portion is changed by operating the control valve to operate the arm portion to adjust the amount of oil discharged from the pump portion. Therefore, even when the rotational speed of the drive shaft that drives the pump unit is constant, the amount of oil discharged from the pump unit can be arbitrarily set by the control of the control valve.

  For example, when oil in the control space is discharged by the control valve, the oil in the control space is sent out through the inside of the control valve. In addition, since the control valve is configured to control oil supply and discharge by the operation of the spool, there is a limit to the flow rate of oil flowing inside the control valve even if the spool is set at a position where oil is discharged. It was. Therefore, even when the amount of oil discharged from the pump unit is reduced, the amount of oil discharged from the control space is small, the operating speed of the arm unit is limited, and there is a possibility that the discharge amount cannot be reduced quickly. .

  In particular, in Patent Document 1, since an oil escape hole is formed in the control space and a constant amount of oil leaks out constantly, oil discharge is promoted when oil is discharged by the control valve. However, when the oil is discharged from the control space, the situation in which the operating speed of the arm portion is limited because the oil flows through the control valve has not been solved.

  An object of the present invention is to configure a variable displacement pump that controls the displacement of the pump unit with high responsiveness.

A feature of the present invention is that it has a drive rotor that discharges fluid by drive rotation, has an operating body that displaces in accordance with the pressure of the fluid in a pressure chamber arranged outside the drive rotor, A pump unit that changes a discharge amount of fluid per unit rotation amount of the drive rotor by displacement;
A pressure control valve for adjusting the pressure of the fluid in the pressure chamber by supplying a part of the fluid from the pump unit to the pressure chamber;
As the pressure of the fluid in the pressure chamber increases, the flow rate of the fluid discharged from the pressure chamber to the drain channel is suppressed, and as the pressure of the fluid in the pressure chamber decreases, the fluid discharges from the pressure chamber to the drain channel. And a discharge control valve that discharges the fuel without suppressing it.

According to this configuration, when the pressure in the pressure chamber is increased by the fluid supplied from the pressure control valve, the discharge control valve suppresses the flow rate of the fluid discharged from the pressure chamber. Thereby, the pressure of the pressure chamber is controlled by the pressure control valve to operate the operating body, and the adjustment of the fluid discharge amount by the pump unit is realized. On the contrary, when the pressure in the pressure chamber is reduced by the fluid supplied from the pressure control valve, the fluid is discharged without being suppressed by the discharge control valve.
In addition, when the pressure control valve for controlling the pressure in the pressure chamber and the discharge control valve for discharging the fluid in the pressure chamber are individually provided, the amount of fluid discharged from the pump unit is greatly reduced. By operating the pressure control valve, it is possible to greatly reduce the pressure in the pressure chamber within a short period of time, greatly actuate the operating body, and change the amount of fluid discharged by the pump unit.
Therefore, a variable displacement pump that controls the displacement of the pump unit with high responsiveness has been constructed.

In the present invention, the discharge control valve is switchable between a suppression position for suppressing the flow rate of the fluid flowing through the drain flow path and a discharge position for discharging the fluid without suppressing the fluid, and the valve body is And an urging body that urges the restraining position.
You may provide the pressure flow path which makes the pressure of the fluid supplied to the said pressure chamber from the said pressure control valve act toward the said suppression position.

  In this configuration, when the pressure in the pressure chamber is increased by the control of the pressure control valve, a part of the fluid from the pressure control valve acts in the direction of the suppression position with respect to the valve body. Thereby, a valve body is maintained in the suppression position and discharge | emission of the fluid from a pressure chamber is restrict | limited. Further, when the pressure in the pressure chamber decreases due to the control of the pressure control valve, the pressure of the fluid acting on the valve body decreases via the pressure flow path, and the valve body of the pressure control valve is operated to the discharge position. As a result, the fluid in the pressure chamber can be discharged without restriction.

  In the present invention, the discharge control valve may discharge while restricting the fluid from the pressure chamber in a state where the valve body is in the suppression position.

Assuming a configuration in which the fluid pressurized by the pump unit leaks to the pressure chamber, even if the amount of leakage is small, no fluid is supplied from the pressure control valve if the pressure chamber is a sealed space. Even in this case, the pressure in the pressure chamber increases, leading to a disadvantage that the discharge amount of the pump unit changes.
On the other hand, by adopting a configuration in which the fluid is continuously discharged from the pressure chamber, even if the fluid pressurized by the pump unit leaks to the pressure chamber, the amount of this leakage amount is taken into account. The pressure of the pressure chamber can be easily set by supplying the fluid from the pressure control valve to the pressure chamber. As a result, the flow rate of the fluid from the pump unit can be adjusted with high accuracy.

  In the present invention, the drain flow path may be communicated with a drain hole formed in the pressure chamber, and the discharge control valve may be disposed at a position near the drain hole.

  According to this, since the distance from the drain hole to the discharge control valve via the drain flow path is short, the pressure is reduced when the discharge control valve switches from the state of suppressing the flow rate of the fluid to be discharged to the state of not suppressing. The chamber pressure can be quickly reduced.

It is a hydraulic circuit diagram which shows the structure of a variable displacement pump. It is sectional drawing of the pump part in a maximum capacity | capacitance. It is sectional drawing of the pump part in a minimum capacity | capacitance.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[Basic configuration]
As shown in FIG. 1, a variable displacement pump is configured including a pump unit P driven by an engine E, a pressure control valve CV formed of an electromagnetic valve, and a discharge control valve DV.

  This variable displacement pump (hereinafter abbreviated as “pump”) supplies lubricating oil (oil: an example of fluid) of an oil pan of the engine E to the main gallery 1 as well as operating oil to the valve timing control device 2. Supply as. The valve opening / closing timing control device 2 sets the intake timing or exhaust timing of the engine E by oil pressure.

  As shown in FIGS. 1 and 2, the pump part P sucks lubricating oil of the oil pan of the engine E into the suction port 11 through the suction flow path 4, and sucks the sucked oil from the discharge port 12 to the oil filter 5. And the supply flow path 6 to the main gallery 1 and the valve timing control device 2. The variable displacement pump discharges a part of the oil sent to the supply passage 6 to the pressure chamber PS of the pump part P via the pressure control valve CV and the oil in the pressure chamber PS. And a drain passage 8 for discharging through the control valve DV.

  The pressure control valve CV realizes increase / decrease (change in pump capacity) of the amount of oil discharged from the pump part P under the control of the control device 50 functioning as an ECU. The discharge control valve DV improves the responsiveness when changing the capacity of the pump.

[Pump part]
As shown in FIGS. 1 and 2, the pump portion P includes an inner rotor 14 as a drive rotor, an outer rotor 15, and an adjustment mechanism 20 in a housing H in which the suction port 11 and the discharge port 12 are formed. Contained.

  The inner rotor 14 has a plurality of external teeth 14A, is supported rotatably about the drive shaft core X, and rotates in the direction indicated by the arrow in the drawing by the drive shaft 13 driven by the engine E. The outer rotor 15 has a plurality of inner teeth 15A that mesh with the outer teeth of the inner rotor 14, and is rotatable about a driven axis Y that is eccentric with respect to the drive axis X.

  The pump part P is also called an internal gear type, and the outer teeth 14A of the inner rotor 14 are formed in a tooth surface shape according to a mathematical curve. The outer periphery of the outer rotor 15 Internal teeth 15A having a number of teeth one more than the number of teeth are formed.

  The adjustment mechanism 20 includes an adjustment ring 21 that rotatably houses the outer rotor 15, an arm portion 22 (an example of an operating body) that is integrally formed with the adjustment ring 21, and a compression coil type that applies a biasing force to the arm portion 22. The adjusting spring 23 is provided. In this adjustment mechanism 20, the guide ring 24 fixed to the housing H is inserted into a pair of elongated guide holes 21 </ b> A formed in the adjustment ring 21. 21 is guided.

  Oil seals 25 are provided at two locations on the outer periphery of the adjustment ring 21 and at the protruding end of the arm portion 22. Thus, a low pressure chamber LS communicating with the suction port 11, a high pressure chamber HS communicating with the discharge port 12, and a pressure chamber PS are formed on the outer periphery of the adjustment ring 21 in the internal space of the housing H. Further, a drain hole 16 communicating with the drain channel 8 and the control channel 7 is formed in the wall surface of the housing H constituting the pressure chamber PS. The control flow path 7 does not necessarily need to be connected to the drain flow path 8, and may directly communicate with the pressure chamber PS.

  In the adjusting mechanism 20, the outer rotor 15 moves in such a manner that the driven shaft core Y revolves around the drive shaft core X by displacing the adjusting ring 21 while being guided by the pair of guide pins 24. By this movement, the meshing relationship in the pressurizing region between the outer teeth 14A of the inner rotor 14 and the inner teeth 15A of the outer rotor 15 is changed, and adjustment of the oil discharge amount is realized.

  That is, when the adjustment ring 21 (arm portion 22) is in the posture shown in FIG. 2, the change in meshing between the outer teeth 14A of the inner rotor 14 and the inner teeth 15A of the outer rotor 15 is large, so that the oil discharge amount is large. Maximum (maximum pump capacity). Further, when the adjustment ring 21 (arm portion 22) is in the posture shown in FIG. 3, the change in meshing between the outer teeth 14A of the inner rotor 14 and the inner teeth 15A of the outer rotor 15 is small, so that the oil discharge amount is minimized. (Pump capacity is minimum).

  Further, the biasing force of the adjustment spring 23 acts in the direction of increasing the amount of oil discharged from the pump part P. As a result, by increasing the pressure acting on the pressure chamber PS, the adjustment ring 21 is operated against the biasing force of the adjustment spring 23, and an arbitrary discharge amount can be obtained.

  In this pump part P, the inner rotor 14 is driven and rotated by the drive shaft 13 driven by the engine E. However, the outer rotor 15 may be driven and rotated by the driving force of the engine E. In this configuration, the outer rotor 15 serves as a drive rotor.

(Pressure control valve)
The pressure control valve CV includes a valve housing 31, a spool 32 that is slidably accommodated in the valve housing 31, a compression coil type spool spring 33 that biases the spool 32 in the closing direction, and a biasing force of the spool spring 33. And an electromagnetic solenoid 34 for operating the spool 32 against the above.

  In the valve housing 31, a supply port 31A communicating with the upstream side (pump portion side) of the control flow path 7 and a control port 31B communicating with the downstream side (pressure chamber side) of the control flow path 7 are formed. . In particular, the control flow path 7 to which oil from the control port 31 </ b> B is supplied communicates with the drain hole 16.

  The spool 32 has a simple configuration in which a single groove is formed between a pair of land portions. Then, by increasing the power supplied to the electromagnetic solenoid 34, the flow rate of oil flowing from the supply port 31A to the control port 31B is increased, and the pressure of the pressure chamber PS is increased.

  In the pressure control valve CV, the position of the spool 32 is set to a position where the flow of oil between the supply port 31A and the control port 31B is prevented in a state where electric power is not supplied to the electromagnetic solenoid 34.

(Discharge control valve)
The discharge control valve DV includes a valve case 41, a valve body 42 that is slidably accommodated with respect to the valve case 41, and a compression coil spring type urging body that urges the valve body 42 in a flow rate suppressing direction. 43. The biasing force of the biasing body 43 is set to a value that causes the valve body 42 to be displaced to the discharge position by the pressure when the oil pressure from the pressure chamber PS acts on the valve body 42 by the biasing force of the adjustment spring 23. Has been.

  A drain flow path 8 communicating with the drain hole 16 is formed in the housing H. The valve case 41 is formed with a supply hole 41A communicating with the upstream side (pressure chamber side) of the drain flow path 8 and a discharge hole 41B communicating with the downstream side (oil pan side) of the drain flow path 8. . Further, a pressure channel 7 </ b> A branched from the control channel 7 communicates with a space in the valve case 41 in which the urging body 43 is accommodated.

  This discharge control valve DV is formed integrally with the housing H of the pump part P or attached to the outer surface of the housing H, so that the relative distance between the drain hole 16 and the supply hole 41A (the length of the drain flow path 8). Is as short as possible.

  The valve body 42 has a configuration in which a predetermined amount of oil is circulated from the supply hole 41A to the discharge hole 41B even in the restrained position shown in FIG. Further, the valve element 42 increases the opening degree when the pressure applied from the drain passage 8 exceeds the combined pressure of the urging force of the urging body 43 and the pressure applied from the pressure passage 7A. The amount of oil flowing from the supply hole 41A to the discharge hole 41B is increased. That is, the valve body 42 is maintained at the suppression position by the pressure applied from the pressure channel 7A, and when no pressure is applied from the pressure channel 7A, the valve body 42 is operated to the discharge position by the pressure in the pressure chamber PS.

  In the pump portion P having such a configuration, it is assumed that a part of the oil pressurized between the inner rotor 14 and the outer rotor 15 flows into the pressure chamber PS due to leakage, leading to an increase in pressure in the pressure chamber PS. . In order to suppress this rise, a configuration is adopted in which the oil in the pressure chamber PS is discharged from the drain hole 16 to the drain channel 8 even when the valve body 42 is in the suppression position.

  Further, in this discharge control valve DV, the flow passage cross-sectional areas of the drain hole 16, the supply hole 41A, and the discharge hole 41B are set to be equal, but when the valve body 42 is set to the suppression position, the drain hole The channel cross-sectional area set by the valve body 42 is smaller than the sixteen channel cross-sectional areas. Thereby, when the valve body 42 is in the suppression position, the oil discharge is limited, and the arm portion 22 is operated by controlling the oil supplied from the pressure control valve CV to control the oil discharge amount of the pump portion P. Is possible. When the valve body 42 is operated to the open position (a position where the discharge hole 41B is fully opened), it is possible to cancel the oil restriction by the valve body 42 and to discharge the oil in a short time.

[Operating form]
When power is not supplied to the electromagnetic solenoid 34 of the pressure control valve CV in a situation where the engine E is operating, the pressure control valve CV is maintained at the closed position shown in FIG. 1, and no oil is supplied to the pressure chamber PS. In addition, since the oil is discharged from the pressure chamber PS through the drain flow path 8 and has a pressure equal to the atmospheric pressure, the pressure in the pressure chamber PS decreases.

  Accordingly, in a situation where the rotational speed of the engine E is low and the amount of oil is reduced, such as when the engine E is started, the control device 50 performs control that does not supply power to the electromagnetic solenoid 34. As a result, the pressure acting on the pressure chamber PS decreases to atmospheric pressure, and the adjustment mechanism 20 sets the oil discharge amount by the pump portion P to the maximum by the urging force of the adjustment spring 23. As a result, the required amount of oil can be supplied to the main gallery 1 while the engine E has a low rotational speed.

  Further, when adjustment of the amount of oil sent from the pump part P to the supply flow path 6 is necessary, the control device 50 adjusts the power supplied to the electromagnetic solenoid 34, so that the control flow path 7 is controlled from the pressure control valve CV. The amount of oil supplied to the pressure chamber PS via the is controlled. Further, when oil is supplied to the pressure chamber PS, the oil pressure from the pressure flow path 7A acts in the direction of the suppression position with respect to the valve body 42 of the discharge control valve DV. Held in position.

  That is, when oil is supplied to the pressure chamber PS, the oil in the pressure chamber PS is discharged from the drain hole 16, but a large amount of oil is discharged because the flow rate is suppressed by the discharge control valve DV. Rather, by supplying an amount of oil that exceeds the discharge amount, the pressure in the pressure chamber PS can be increased, decreased, or maintained. Thereby, the adjustment ring 21 is operated integrally with the arm portion 22 to a position corresponding to the pressure of the oil acting on the pressure chamber PS, and the adjustment of the oil discharge amount is realized.

  Further, in the situation where the engine E is operating, when the amount of oil to be supplied to the main gallery 1 or the like is required, the control device 50 performs control that does not supply power to the electromagnetic solenoid 34 of the pressure control valve CV. Done.

  As a result, the pressure chamber PS is switched to a state in which no oil is supplied, and at the same time, in the discharge control valve DV, the pressure of the oil acting on the valve body 42 from the pressure flow path 7A is released. Switch to the open state.

  The oil in the pressure chamber PS flows and is discharged from the drain hole 16 without being suppressed with respect to the drain flow path 8. As a result, the pressure in the pressure chamber PS is reduced to atmospheric pressure, the adjustment ring 21 of the adjustment mechanism 20 reaches the position shown in FIG. 1 by the urging force of the adjustment spring 23, and the discharge amount of the pump part P is maximized.

[Operation / Effect of Embodiment]
Thus, the variable displacement pump of the present invention has a basic configuration in which the discharge amount of the pump part P is set by controlling the pressure acting from the oil. In addition to the pressure control valve CV that controls the amount of oil supplied to the pressure chamber PS, the pump unit P includes a discharge control valve DV that controls the discharge of oil from the pressure chamber PS. Responsiveness when increasing the amount of oil discharged is improved.

  Further, the discharge control valve DV is formed integrally with the housing H of the pump part P, etc., so that the distance of the drain flow path 8 from the drain hole 16 to the supply hole 41A of the discharge control valve DV is shortened. When 42 is switched to the discharge position, the oil is quickly discharged.

  The present invention can be used for a variable displacement pump that changes its capacity according to the pressure of a fluid.

7A Pressure channel 8 Drain channel 14 Drive rotor (inner rotor)
16 Drain hole 22 Actuator (Adjustment ring)
42 Valve body 43 Energizing body P Pump part PS Pressure chamber CV Pressure control valve DV Discharge control valve

Claims (4)

A driving rotor that discharges fluid by driving rotation; an operating body that displaces corresponding to the pressure of fluid in a pressure chamber disposed outside the driving rotor; A pump unit that changes the fluid discharge rate per unit rotation amount;
A pressure control valve for adjusting the pressure of the fluid in the pressure chamber by supplying a part of the fluid from the pump unit to the pressure chamber;
As the pressure of the fluid in the pressure chamber increases, the flow rate of the fluid discharged from the pressure chamber to the drain channel is suppressed, and as the pressure of the fluid in the pressure chamber decreases, the fluid discharges from the pressure chamber to the drain channel. A variable displacement pump configured to include a discharge control valve that discharges the fuel without suppressing it. The discharge control valve is provided with a valve body that can be switched between a suppression position for suppressing the flow rate of the fluid flowing through the drain flow path and a discharge position for discharging the fluid without suppressing the fluid, and the valve body is attached to the suppression position. And an urging body for energizing,
The variable displacement pump according to claim 1, further comprising a pressure channel that causes the pressure of the fluid supplied from the pressure control valve to the pressure chamber to act toward the suppression position.   3. The variable displacement pump according to claim 2, wherein the discharge control valve restricts and discharges the fluid from the pressure chamber in a state where the valve body is in a suppression position.   The variable capacity type according to any one of claims 1 to 3, wherein the drain flow path communicates with a drain hole formed in the pressure chamber, and the discharge control valve is disposed at a position near the drain hole. pump.

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