JP2014134185A - Oil pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an oil pump capable of detecting biting of foreign matters.SOLUTION: An oil pump 100 comprises: a casing 1 on which a suction port 2 and an emission port 3 are formed and that includes an inner rotor 12 and an outer rotor 13; an operation part 50 that is provided on an outer periphery of an adjustment ring 14 for relatively rotatably supporting the outer rotor 13, and to which a driving force is inputted: a guide part G that is provided to the casing 1 and the adjustment ring 14 and guides the adjustment ring 14 so that an axial core of the outer rotor 13 revolves around an axial core of the inner rotor 12 as a center according to the driving force inputted to the operation part 50; a driving force control part 16 for controlling the driving force inputted to the operation part 50 so that pressure of the oil emitted from the emission port 3 reaches required hydraulic pressure; and a biting determination part 17 for determining whether biting of foreign matters occurs between the casing 1 and the adjustment ring 14 based on the required hydraulic pressure and the pressure of the oil emitted from the emission port 3.

Description

  The present invention relates to a variable displacement oil pump.

  2. Description of the Related Art Conventionally, variable displacement oil pumps that can change the suction amount and discharge amount of a pump have been used. As such a variable displacement type oil pump, for example, an inner rotor having external teeth and driven around a driving rotation axis, and an inner tooth engaging with the inner rotor in an eccentric state, and rotating around a driven axis. Some have an outer rotor provided inside the casing. This type of oil pump is provided with an adjustment ring that revolves the driven center of the outer rotor around the driving rotation axis in a state where the inner rotor and the outer rotor mesh with each other, and the adjustment ring is displaced to displace the outer rotor. The pump capacity can be changed by revolving.

  In changing the pump capacity in this way, in the variable capacity type oil pump, the outer rotor is configured to revolve with respect to the inner rotor, so the size of the gap formed between the casing and the outer rotor Changes. When foreign matter is caught between the casing and the adjustment ring, the range in which the outer rotor can revolve is limited with respect to the preset maximum range. May deviate from pressure. Therefore, techniques for detecting whether or not such foreign matter is bitten have been studied (for example, Patent Documents 1 and 2).

  The hydraulic control device for an internal combustion engine described in Patent Literature 1 includes a pressure stage switching mechanism, a detection unit, and a determination unit. The pressure stage switching mechanism controls the oil pressure by switching the pressure of the oil supplied to each part of the engine between a high pressure state and a low pressure state. The detecting means detects the pressure of the oil after being controlled by the pressure stage switching mechanism. The determination means is assumed when the oil pressure detected by the detection means is in a high pressure state in a state in which a command to set the oil pressure to a high pressure state is output to the pressure stage switching mechanism. It is determined that an abnormality has occurred in the pressure stage switching mechanism when the value falls below a predetermined abnormality determination value that is set between a value and a value that is assumed when the pressure is low. Alternatively, when the oil pressure detected by the detecting means is in a high pressure state in a state where a command is output to the pressure stage switching mechanism to set the oil pressure to a low pressure state, the determination means is It is determined that an abnormality has occurred in the pressure stage switching mechanism when it exceeds a predetermined abnormality determination value that is set between a value that is assumed and a value that is assumed when the pressure is low.

  In addition, the abnormality determination system for the oil pump mechanism described in Patent Document 2 is detected after the control state of the oil pump mechanism is switched from the high pressure control state to the low pressure control state by the oil pressure control unit or by the cooling water temperature detection unit. The engine in the idle state after the control state of the oil pump mechanism is switched from the low pressure control state to the high pressure control state by the oil pressure control unit when the temperature of the cooled cooling water is lower than the predetermined temperature. It is determined whether or not the oil pump mechanism is abnormal based on the change in the rotational speed. Further, the abnormality determination system includes a required displacement time required for the variable valve timing mechanism unit to be displaced by a required displacement amount that represents a displacement amount required for the variable valve timing mechanism unit by the valve timing control unit, It is determined whether or not the oil pump mechanism is abnormal based on the actual displacement time until the displacement amount is reached. Furthermore, the abnormality determination system determines whether or not the oil pump mechanism is abnormal based on the actual displacement calculated by the actual displacement calculator and the requested displacement requested by the valve timing controller. .

JP 2010-116890 A JP 2010-48205 A

  The techniques described in Patent Document 1 and Patent Document 2 described above can be applied to an oil pump that performs switching control of the discharge pressure in two stages of a high pressure state and a low pressure state. However, it is difficult to apply to an oil pump that performs control such as switching the discharge pressure in three or more stages. That is, for example, in a variable oil pump that switches oil pressure in three stages, when controlling in an intermediate pressure state between a low pressure state and a high pressure state, the state shifts from a high pressure state to an intermediate pressure state when performing abnormality detection. And when shifting from the low pressure state to the intermediate pressure state, the determination threshold value must be set separately. Further, when undershoot and overshoot are taken into account, even if the determination threshold value is set separately, the determination cannot be made. There is. Therefore, since the determination logic is complicated, it is not easy to apply to a variable displacement oil pump that switches between three or more discharge pressures. Further, the techniques described in Patent Literature 1 and Patent Literature 2 are for detecting an abnormality. For example, when a switching operation is locked by biting a foreign object, the technology is not considered until the lock is released. .

  In view of the above problems, an object of the present invention is to provide an oil pump capable of detecting biting of foreign matter.

The characteristic configuration of the oil pump according to the present invention for achieving the above object is as follows:
An inner rotor having a plurality of external teeth and rotating about a first rotation axis;
An outer rotor that is formed in an annular shape having a plurality of internal teeth that mesh with the external teeth, and that rotates according to the rotation of the inner rotor at a second rotational axis that is eccentric with respect to the first rotational axis;
A suction port that supplies oil between the external teeth and the internal teeth, and a discharge port that discharges oil supplied from the suction ports as the inner rotor rotates from between the external teeth and the internal teeth And a casing enclosing the inner rotor and the outer rotor;
An adjustment ring that supports the outer rotor so as to be relatively rotatable from the radially outer side in a state where the outer teeth and the inner teeth mesh with each other;
An operation unit provided on an outer peripheral surface of the adjustment ring, to which a driving force is input;
The adjustment ring is provided on the casing and the adjustment ring, and guides the adjustment ring so that the second rotation axis revolves around the first rotation axis according to a driving force input to the operation unit. A guide part;
A discharge pressure detector that detects the pressure of oil discharged from the discharge port;
A driving force control unit that controls the driving force input to the operation unit such that the pressure of oil discharged from the discharge port becomes a desired required oil pressure;
A biting determination unit that determines whether there is a biting of foreign matter between the casing and the adjustment ring based on the required oil pressure and a detection result of the discharge pressure detection unit;
It is in the point equipped with.

  With such a characteristic configuration, the pressure of the oil discharged from the discharge port is compared with the required oil pressure. If the pressure of the oil discharged from the discharge port does not reach the required oil pressure, the casing and the adjustment ring It can be easily determined that a foreign object is caught between the two.

  Further, it is preferable that the rotational power of the engine is transmitted to the inner rotor, and the required oil pressure is preset according to the rotational speed of the engine.

  The engine speed fluctuates in accordance with the driving state of the vehicle such as the oil temperature and engine load. Therefore, with such a configuration, it is possible to determine whether or not a foreign object is bitten in real time according to the driving state of the vehicle.

  In addition, it is preferable that a temperature detection unit for detecting the temperature of the oil is provided, and the biting determination unit is determined in consideration of the temperature of the oil detected by the temperature detection unit.

  It is known that the viscosity of oil changes with temperature. For this reason, it is conceivable that the discharge pressure changes depending on the temperature of the oil. Therefore, with this configuration, even when the viscosity of the oil changes, it is possible to appropriately determine the foreign matter bite.

  In addition, it is preferable that the biting determination unit performs a preliminary determination based on a hydraulic pressure gradient when a predetermined time elapses after the driving force control unit controls the driving force.

  The time until the pressure of the oil discharged from the discharge port reaches the required oil pressure, that is, the oil pressure gradient, can be predicted if the current oil pressure, oil temperature, and engine speed are known. For this reason, if the current hydraulic pressure gradient is significantly different from the predicted hydraulic pressure gradient, there is some abnormality in the oil pump until the pressure of the oil discharged from the discharge port settles to a predetermined value. Can be recognized in advance.

  The driving force control unit preferably increases or decreases the driving force input to the operation unit based on the current driving force when it is determined that the foreign matter is bitten.

  With such a configuration, the second rotation axis can be repeatedly rotated around the first rotation axis in the clockwise direction and in the reverse direction. Accordingly, since the adjustment ring can be moved in a shaking manner, it is possible to easily release the foreign object.

  Further, when it is determined that the foreign matter has been caught, even if the driving force control unit increases or decreases the driving force input to the operation unit, the pressure of the oil discharged from the discharge port is increased. It is preferable to provide an explicit part that clearly indicates to the user that the foreign object is bitten when the desired hydraulic pressure is not reached.

  With this configuration, it is possible to clearly indicate to the user that the foreign object has not been released as a result of attempting to release the foreign object. Therefore, it is possible to prompt the user for maintenance.

It is sectional drawing of the oil pump in a pump capacity | capacitance maximum state. It is sectional drawing of the oil pump in a pump capacity minimum state. It is a figure which shows the determination threshold value utilized when determining the presence or absence of the biting of a foreign material. It is a figure which shows the example of the state which bitten the foreign material. It is a figure which shows the example of the state which bitten the foreign material. It is a figure which shows the releasing operation | movement of the biting of a foreign material. It is a figure which shows the releasing operation | movement of the biting of a foreign material. It is a flowchart which shows the process of an oil pump. It is a figure which shows the criteria used when performing preliminary determination.

  The oil pump according to the present invention is configured to have a function of detecting that a movable part in the oil pump has bitten a foreign object. Hereinafter, the oil pump 100 of the present embodiment will be described in detail. FIG. 1 shows a variable displacement oil pump 100 whose discharge pressure can be changed as an example of the oil pump 100. In the present embodiment, the oil pump 100 is mounted on a vehicle and driven by the engine of the vehicle. The use is for supplying oil for lubricating the engine and supplying oil to hydraulic equipment such as an engine valve opening / closing timing control device.

  The oil pump 100 according to the present embodiment includes an inner rotor 12, an outer rotor 13, an adjustment ring 14, a suction port 2, a discharge port 3, an operation unit 50, a guide unit G, a driving force control unit 16, a biting determination unit 17, A discharge pressure detection unit 18 and an explicit unit 19 are provided. In particular, the driving force control unit 16, the bite determination unit 17, and the indication unit 19 are constructed with hardware and / or software to perform various processes for determining whether or not a foreign object is bitten, with the CPU as a core member. Has been.

  The inner rotor 12 has a plurality of external teeth 12A and rotates about the first rotation axis X. The inner rotor 12 is formed in an annular shape, and a plurality of external teeth 12A are formed on the outer peripheral surface thereof. These external teeth 12A are configured in a tooth surface shape according to a trochoid curve, a cycloid curve, or the like. In the present embodiment, the rotational power of the engine is transmitted to the inner rotor 12. The engine is a power source of a vehicle on which the oil pump 100 is mounted. The inner rotor 12 is disposed coaxially with the first rotation axis X, is rotatably supported with respect to the casing 1 via a drive shaft 11 to which the rotational power of the engine is transmitted, and rotates integrally with the drive shaft 11. To do.

  The outer rotor 13 is formed in an annular shape having a plurality of internal teeth 13A meshing with the external teeth 12A, and rotates according to the rotation of the inner rotor 12 with a second rotation axis Y that is eccentric with respect to the first rotation axis X. To do. The outer rotor 13 is also formed in an annular shape like the inner rotor 12, and a plurality of internal teeth 13 </ b> A are formed on the inner peripheral surface thereof, and is provided rotatably about the second rotation axis Y. The inner teeth 13A of the outer rotor 13 are configured to have one more tooth than the outer teeth 12A of the inner rotor 12, and when the outer rotor 13 rotates, the tooth surface that contacts the outer teeth 12A of the inner rotor 12 It is molded into a shape. Therefore, a predetermined gap Q is provided between the outer teeth 12A and the inner teeth 13A. Further, the second rotation axis Y is provided eccentrically with respect to the first rotation axis X, and is configured such that the respective rotation centers are different.

  The casing 1 includes an inner rotor 12 and an outer rotor 13. Encapsulating means including and configuring inside. Therefore, the inner rotor 12 and the outer rotor 13 are provided in the casing 1.

  Further, a suction port 2 and a discharge port 3 are formed in the casing 1. The suction port 2 is an opening formed in the wall 1 </ b> A of the casing 1. Specifically, the suction port 2 is provided on the wall 1 </ b> A facing the axial end surface of the outer rotor 13 in the inner wall of the casing 1, and is provided along the radial direction of the outer rotor 13. From such a suction port 2, oil is supplied between the external teeth 12A and the internal teeth 13A. Between the external teeth 12A and the internal teeth 13A is the predetermined gap Q described above. As a result, oil is supplied to the gap Q between the outer teeth 12 </ b> A and the inner teeth 13 </ b> A from the suction port 2 provided on the axial end portions of the inner rotor 12 and the outer rotor 13.

  Similarly to the suction port 2, the discharge port 3 also includes an opening formed in the wall portion 1 </ b> A of the casing 1. Specifically, the discharge port 3 is provided on the wall portion 1 </ b> A facing the axial end surface of the outer rotor 13 in the inner wall of the casing 1, and is provided along the radial direction of the outer rotor 13. In the present embodiment, the discharge port 3 is provided on the wall portion 1A on the side where the suction port 2 is provided. That is, the suction port 2 and the discharge port 3 are provided in the wall portion 1A facing the same direction. Moreover, the opening part which comprises the discharge port 3 is spaced apart from the opening part which comprises the suction port 2, and is provided along the radial direction of the outer rotor 13. As shown in FIG. From such a discharge port 3, the oil supplied from the suction port 2 with the rotation of the inner rotor 12 is discharged from between the outer teeth 12A and the inner teeth 13A. Between the external teeth 12A and the internal teeth 13A is the predetermined gap Q described above. Accordingly, oil flows out from the gap Q between the outer teeth 12A and the inner teeth 13A to the discharge port 3 provided on the side of the inner rotor 12 and the outer rotor 13 in the axial direction.

  In the oil pump 100, the inner rotor 12 is driven to rotate in the direction of arrow A. Therefore, when the adjustment ring 14 is in the posture (initial position) shown in FIG. 1, the negative pressure acting region that reduces the pressure between the outer teeth 12 </ b> A of the inner rotor 12 and the inner teeth 13 </ b> A of the outer rotor 13 is used. The suction port 2 faces, and the discharge port 3 faces a positive pressure acting region that compresses oil between the outer teeth 12A of the inner rotor 12 and the inner teeth 13A of the outer rotor 13. This functions to suck oil from the suction port 2 and send oil from the discharge port 3.

  The adjustment ring 14 supports the outer rotor 13 so as to be relatively rotatable from the outside in the radial direction in a state where the outer teeth 12A and the inner teeth 13A are engaged with each other. The adjustment ring 14 is formed in a ring shape having an inner peripheral surface coaxial with the second rotation axis Y so as to insert the outer rotor 13 therein. In addition, the outer periphery of the outer rotor 13 is formed in a circular shape centered on the second rotation axis Y. As a result, the center position of the inner periphery of the adjustment ring 14 and the position of the second rotation axis Y of the outer rotor 13 coincide with each other, and the adjustment ring 14 supports the outer peripheral surface of the outer rotor 13 on its inner peripheral surface. It is possible.

  The operation unit 50 is provided on the outer peripheral surface of the adjustment ring 14 and receives driving force. In the present embodiment, the first arm portion 53 and the second arm portion 54 that protrude in the direction away from the second rotation axis Y from the outer peripheral surface of the adjustment ring 14 correspond to the operation portion 50. Below, when it is not necessary to distinguish the 1st arm part 53 and the 2nd arm part 54 in particular, it demonstrates generically as the operation part 50, and is demonstrated. The driving force is a driving force that revolves the second rotational axis Y of the outer rotor 13 around the first rotational axis X of the inner rotor 12 as described later. Here, the outer rotor 13 is accommodated in the adjustment ring 14 so as to be relatively rotatable. For this reason, the adjustment ring 14 revolves around the first rotation axis X as the second rotation axis Y revolves. Therefore, the driving force input to the operation unit 50 corresponds to a driving force for revolving the adjustment ring 14 itself.

  The guide portion G is provided on the casing 1 and the adjustment ring 14 and is adjusted so that the second rotation axis Y revolves around the first rotation axis X according to the driving force input to the operation unit 50. Guide the ring 14. In the present embodiment, guide pins 31 that are parallel to the first rotation axis X are formed to protrude at two locations on the outer peripheral surface of the adjustment ring 14. A guide groove 32 into which the protruding ends of these two guide pins 31 are fitted is formed in the wall portion 1A of the casing 1. The two guide pins 31 and the two guide grooves 32 constitute a guide portion G.

  In addition, an engagement recess 36 is formed at a position opposite to the guide portion G on the outer peripheral portion of the adjustment ring 14. A support recess 37 is formed in the casing 1 at a position facing the engagement recess 36. A seal vane 38 is disposed between the engagement recess 36 and the support recess 37.

  Here, a pressurized space 1Q in which the discharge pressure from the discharge port 3 acts is formed inside the casing 1, and the first pressure chamber 51 on the high pressure side in which the oil pressure in the pressurized space 1Q directly acts. And a second pressure chamber 52 on the low pressure side in which the pressure of the oil in the pressurizing space 1Q acts via the electromagnetic valve V is formed. The oil pressure in the first pressure chamber 51 acts on the first arm portion 53 described above, and the oil pressure in the second pressure chamber 52 acts on the second arm portion 54. The second arm portion 54 has a larger pressure receiving area than the first arm portion 53, and the compression coil spring 6 is disposed on the opposite side to the direction in which the oil pressure acts.

  In the oil pump 100, oil in the pressurized space 1Q is supplied to the electromagnetic valve V via the oil filter 55, and oil from the electromagnetic valve V is supplied to the second pressure chamber 52 via the oil passage 56. A road is formed. The oil passage 56 is formed in the casing 1 in a groove shape.

  In the oil pump 100, the protruding end of the first arm portion 53 is brought into sliding contact with the inner peripheral surface of the first pressure chamber 51 when the adjustment ring 14 is operated. The oil supplied to the first arm portion 53 operates the adjusting ring 14 without leaking. Also, with this configuration, the first arm portion 53 functions as a blocking portion that prohibits the flow of oil between the first pressure chamber 51 and the second pressure chamber 52.

  The protruding end of the second arm portion 54 is also in sliding contact with the inner peripheral surface of the second pressure chamber 52. The adjustment ring 14 is operated without leaking the oil supplied to the second pressure chamber 52. When the adjustment ring 14 moves from the posture shown in FIG. 1 to the posture shown in FIG. 2, the oil pump 100 has a second meshing relationship between the outer teeth 12 </ b> A of the inner rotor 12 and the inner teeth 13 </ b> A of the outer rotor 13. The rotation axis Y is configured to reach a positional relationship obtained by revolving 90 degrees.

  The discharge pressure detection unit 18 detects the pressure of oil discharged from the discharge port 3. The discharge pressure detection part 18 is comprised by the pressure sensor which detects the pressure of oil. The oil discharged from the discharge port 3 corresponds to oil immediately after discharge from the discharge port 3 or oil supplied to the main gallery M as hydraulic equipment such as the valve opening / closing timing control device described above. In the present embodiment, the discharge pressure detection unit 18 detects the pressure of oil supplied to the main gallery M. Hereinafter, “pressure of oil discharged from the discharge port 3” will be described as “discharge pressure”. A detection result by the discharge pressure detection unit 18 is transmitted to a driving force control unit 16 and a bite determination unit 17 which will be described later.

  The driving force control unit 16 controls the driving force input to the operation unit 50 so that the pressure of oil discharged from the discharge port 3 becomes a desired required oil pressure. The oil pressure of the oil discharged from the discharge port 3, that is, the discharge pressure is transmitted as a detection result of the discharge pressure detection unit 18 described above. In this embodiment, a desired required oil pressure is set in advance according to the engine speed. This is because the hydraulic pressure required for the main gallery M differs depending on the engine speed. Such a required oil pressure is preferably stored in advance in the driving force control unit 16 as a map that defines the relationship between the engine speed and the required oil pressure. An example of such a map is shown in FIG. Rotational speed information indicating the current rotational speed of the engine is also transmitted from the engine to the driving force control unit 16.

  Such a driving force control part 16 is comprised by ECU etc., and controls the solenoid valve V based on required hydraulic pressure. As specific examples of the control, a low pressure control mode, a high pressure control mode, and a DUTY control mode for repeatedly changing the low pressure control and the high pressure control are set. Specifically, it may be changed between the low pressure control and the high pressure control, or may be changed by appropriately setting each DUTY. Furthermore, the DUTY set value may be exchanged at a constant cycle or may be changed at random. Moreover, you may set suitably the period which replaces DUTY setting value.

  In the high pressure control mode, the solenoid valve V is set to a position that prevents oil from coming out of the pressurizing space 1Q and opens the second pressure chamber 52 to the atmosphere. Accordingly, the adjustment ring 14 can be operated by applying the oil pressure in the pressurizing space 1Q to the first arm portion 53.

  In the low pressure control mode, the electromagnetic valve V is set to a position where oil from the pressurizing space 1Q is applied to the second arm portion 54 via the oil passage 56. Thereby, it is possible to operate the adjustment ring 14 at a pressure lower than the pressure to operate the adjustment ring 14 in the high pressure control mode by applying the oil pressure in the pressurized space 1Q to the second arm portion 54. Become.

  In this way, by setting the driving force control unit 16 to the low pressure control mode, the amount of oil discharged from the oil pump 100 can be reduced even when the engine speed is low, or only when the engine speed is high. An operation for reducing the amount of oil discharged from the oil pump 100 is realized. Accordingly, it is possible to suppress an inconvenience that the excessive amount of oil is discharged based on the conditions or the discharge pressure is excessively increased to deteriorate the fuel consumption of the engine.

  The driving force control unit 16 controls the solenoid valve V so that the detection result of the discharge pressure detection unit 18 matches the required hydraulic pressure set according to the current engine speed, and inputs the control valve 14 to the adjustment ring 14. The driving force to be controlled is controlled by feedback control.

  Thereby, the inner rotor 12 and the outer rotor 13 can be brought into the state shown in FIG. 1 or the state shown in FIG. That is, in the state of FIG. 1, the drive shaft 11 is driven and rotated as described above, whereby oil is sucked from the suction port 2 and oil is discharged from the discharge port 3.

  On the other hand, in the state of FIG. 2, the movement of the second rotation axis Y revolving around the first rotation axis X is performed, and at the same time, the adjustment ring 14 rotates around the second rotation axis Y. To do. Therefore, at this time, the outer rotor 13 also moves together, and the second rotation axis Y revolves around the first rotation axis X in a state where the outer teeth 12A of the inner rotor 12 are engaged with the inner teeth 13A of the outer rotor 13.

  In this way, the positive pressure acting region and the negative pressure acting region move around the first rotation axis X, the negative pressure acting on the suction port 2 from the negative pressure acting region decreases, and the discharge port from the positive pressure acting region. The positive pressure acting on 3 also decreases. As a result, the amount of oil supplied by the oil pump 100 is reduced.

  When the adjustment ring 14 is moved to the moving end position shown in FIG. 2, the negative pressure acting region and the positive pressure acting region are in a positional relationship across the suction port 2 and the discharge port 3. For this reason, almost no negative pressure acts on the suction port 2, and almost no positive pressure acts on the discharge port 3. For this reason, oil is not supplied or discharged, and as a result, the amount of oil discharged is reduced.

  Thus, in the present oil pump 100, the adjustment ring 14 revolves around the second rotation axis Y by 90 degrees. At this time, in a normal state, there is a portion where the adjustment ring 14 and the casing 1 are close to each other. However, if a foreign object is caught in such an adjacent part, the second rotational axis Y is around the first rotational axis X even if the driving force control unit 16 tries to control the discharge pressure to the desired required hydraulic pressure. In this case, the target hydraulic pressure may not be reached because the revolution does not revolve by the amount corresponding to the desired angle.

  That is, when the foreign matter J is caught between the casing 1 and the adjustment ring 14 at the position shown in FIG. 4, the adjustment ring 14 cannot move to the position shown in FIG. Therefore, the desired required hydraulic pressure that is uniquely determined cannot be maintained, and a phenomenon occurs in which the hydraulic pressure increases or decreases. On the other hand, when the foreign matter J is caught between the casing 1 and the adjustment ring 14 at the position shown in FIG. 5, the adjustment ring 14 cannot move to the position shown in FIG. In such a case as well, a desired required hydraulic pressure that is uniquely determined cannot be maintained, and a phenomenon occurs in which the hydraulic pressure increases or decreases. Therefore, the oil pump 100 includes a biting determination unit 17 that determines whether or not a foreign object is bitten.

  The bite determination unit 17 determines whether there is a foreign object bit between the casing 1 and the adjustment ring 14 based on the required oil pressure and the detection result of the discharge pressure detection unit 18. In the present embodiment, the required hydraulic pressure is stored in advance in the form of a map in the driving force control unit 16 as described above. Therefore, the required hydraulic pressure is transmitted from the driving force control unit 16 to the biting determination unit 17. Further, the detection result of the discharge pressure detection unit 18 is also transmitted to the biting determination unit 17. This detection result corresponds to the current discharge pressure. The biting determination unit 17 compares the required oil pressure with the detection result of the discharge pressure detection unit 18. Here, when the driving force is controlled by the driving force control unit 16, the discharge pressure usually reaches the desired required oil pressure in about several tens of milliseconds to several hundreds of milliseconds. Therefore, the biting determination unit 17 has the current discharge pressure significantly deviated from the required oil pressure even after a predetermined time (for example, about several hundred milliseconds or more) has passed after the driving force control by the driving force control unit 16. In this case, it is determined that there is a foreign matter bite. On the other hand, when the current discharge pressure is within a predetermined range based on the required oil pressure, it is determined that no foreign matter is caught. The biting determination unit 17 transmits the determination result to the driving force control unit 16.

  It is preferable to use a map as shown in FIG. 3 for the determination of the presence or absence of such foreign matter. FIG. 3 is a map defining the relationship between the required oil pressure and the engine speed as described above. A determination threshold is provided with a predetermined width for such a required oil pressure. For example, it is preferable that the determination threshold value is set such that + 10% of the required oil pressure is the upper limit oil pressure and −10% is the lower limit oil pressure. Of course, this ± 10% can be changed. Further, in a state where the engine speed is low, the discharge pressure does not theoretically become higher than the required oil pressure, so that it is not necessary to provide the upper limit oil pressure as shown in FIG.

  The driving force control unit 16 according to the present embodiment increases / decreases the driving force input to the operation unit 50 based on the current driving force when it is determined that a foreign object is bitten. The biting of the foreign matter occurs between the casing 1 and the adjustment ring 14 and is determined by the biting determination unit 17. The driving force control unit 16 controls the driving force input to the operation unit 50 so that the discharge pressure becomes a desired required oil pressure as described above. When it is determined that there is a foreign object bitten, the driving force control unit 16 increases or decreases the driving force input to the operation unit 50 with a predetermined width around the current driving force. Accordingly, as shown in FIG. 6 or FIG. 7, the second rotation axis Y revolves around the first rotation axis X around the current position. As a result, the driving force input to the operation unit 50 of the adjustment ring 14 is alternately pushed and pulled, and the adjustment ring 14 is moved so as to be shaken. Such an operation is preferably controlled so as to forcibly and repeatedly change the state of the electromagnetic valve V. Thereby, since the part which adjoined between the casing 1 and the adjustment ring 14 will separate, it will become possible to cancel | release the biting of the foreign material between the casing 1 and the adjustment ring 14. FIG.

  Note that the change of the state of the electromagnetic valve V described above may be performed with a constant cycle or may be performed while changing the cycle. When the period is changed, it may be gradually increased or may be changed randomly. In addition, when the solenoid valve V is not an on-off valve as shown in FIG. 1 and is configured to open and close by DUTY control, it can be realized by repeatedly changing the DUTY to be larger or smaller. is there. Specifically, the on-duty may be changed between 100% and 0%, or may be changed by appropriately setting each DUTY. Furthermore, the DUTY set value may be exchanged at a constant cycle or may be changed at random. Moreover, you may change suitably the period which replaces a DUTY setting value. Furthermore, when the resonance frequency of the adjustment ring 14 and the compression coil spring 6 is known, the adjustment ring 14 resonates and is easily released by driving at that frequency.

  When foreign matter is removed from between the casing 1 and the adjustment ring 14 by such control, the driving force control unit 16 can appropriately control the discharge pressure to be a desired required oil pressure. Become. Therefore, the driving force control unit 16 performs the feedback control described above. On the other hand, if the foreign matter cannot be removed even if the above-described control is performed, that is, if the detection result of the discharge pressure detection unit 18 is significantly deviated from the desired hydraulic pressure, the biting determination unit 17 continues. It is determined that a foreign object is caught. In such a case, the driving force control unit 16 stops the feedback control described above. Then, the biting determination unit 17 is notified to the explicit unit 19 described later. The engine valve opening / closing timing control apparatus cannot be supplied with the desired hydraulic pressure, so that it is preferable that the engine is stopped at a position at which the vehicle can travel.

  When it is determined that there is a foreign matter bite, the clarification unit 19 increases or decreases the amount of oil discharged from the discharge port 3 even if the driving force control unit 16 increases or decreases the driving force input to the operation unit 50. If the oil pressure does not reach the desired oil pressure, the user is clearly informed that a foreign object has been caught. When it is determined that foreign matter has been caught, even if the driving force control unit 16 increases or decreases the driving force input to the operation unit 50, the discharge pressure does not become the desired required oil pressure. This is notified by the inclusion determination unit 17. Upon receiving this notification, the clarification unit 19 clearly indicates that the user has bitten foreign matter. This indication may be in a form in which a warning sound is emitted and indicated, or in a form in which the lamp is flashed or turned on.

  Next, processing related to the detection of the above-mentioned foreign object biting will be described with reference to the flowchart of FIG. When the engine is started, the driving force control unit 16 acquires the rotation speed information indicating the rotation speed of the engine (step # 1), and acquires the required oil pressure corresponding to the rotation speed indicated by the rotation speed information (step # 2). . Further, as the engine is started, the discharge pressure detection unit 18 detects the discharge pressure, and the result is transmitted to the driving force control unit 16. Therefore, the driving force control unit 16 acquires the discharge pressure (step # 3).

  The driving force control unit 16 controls the driving force input to the operation unit 50 so that the acquired discharge pressure becomes the required hydraulic pressure (step # 4). This control is performed by the driving force control unit 16 controlling the opening and closing of the electromagnetic valve V. Thereafter, the biting determination unit 17 determines whether foreign matter is bitten between the casing 1 and the adjustment ring 14. After the above control is performed, if the discharge pressure is within a predetermined range set with the required oil pressure as a reference (step # 5: No), the biting determination unit 17 may be a foreign object between the casing 1 and the adjustment ring 14. Is determined not to be bitten, and the process returns to step # 1 to continue processing.

  On the other hand, if the discharge pressure is not within the predetermined range set with the required oil pressure as a reference even after a predetermined time has elapsed after the above-described control has been performed (step # 5: Yes), the biting determination unit 17 Determines that a foreign object is caught between the casing 1 and the adjustment ring 14 and notifies the driving force control unit 16 of the result.

  When the driving force control unit 16 receives notification from the biting determination unit 17 indicating that a foreign object is bitten between the casing 1 and the adjustment ring 14, the driving force control unit 16 increases or decreases the driving force based on the current driving force. (Step # 6). Thereby, the adjustment ring 14 moves as if it was shaken with respect to the casing 1.

  Thereafter, if the discharge pressure falls within a predetermined range set with reference to the required oil pressure (step # 7: No), it is determined that foreign matter has been removed from between the casing 1 and the adjustment ring 14, and the processing from step # 1 is performed. Will continue. On the other hand, if the discharge pressure is not within the predetermined range set with the required oil pressure as a reference even after the predetermined time has elapsed (step # 7: Yes), since the foreign matter has not been released, the explicit part 19 clearly indicates that the oil pump 100 has failed (step # 8). In this way, processing related to the detection of foreign matter is performed.

[Other Embodiments]
In the above embodiment, the oil pump 100 is described as being mounted on a vehicle and driven by the engine of the vehicle. However, the scope of application of the present invention is not limited to this. The oil pump 100 can be configured without being mounted on the vehicle, and can naturally be configured not to be driven by the engine, for example, to be driven by an electric motor or the like.

  In the above-described embodiment, it has been described that the required oil pressure is preset according to the engine speed. However, the scope of application of the present invention is not limited to this. It is also possible to employ a configuration in which the required oil pressure is calculated every time the engine speed is acquired.

  In the above-described embodiment, it has been described that the map that defines the required oil pressure and the engine speed is stored in the driving force control unit 16 in advance. However, the scope of application of the present invention is not limited to this. Of course, it is also possible to adopt a configuration in which the required oil pressure is transmitted from another arithmetic processing unit.

  In the above-described embodiment, the driving force control unit 16 has been described as increasing or decreasing the driving force input to the operation unit 50 based on the current driving force when it is determined that a foreign object is bitten. However, the scope of application of the present invention is not limited to this. Of course, even if it is determined that there is a foreign matter bite, the driving force control unit 16 may be configured not to increase or decrease the driving force.

  In the above embodiment, when it is determined that foreign matter has been caught, even if the driving force control unit 16 increases or decreases the driving force input to the operation unit 50, the discharge pressure does not become the required oil pressure. The description unit 19 has been described as clearly indicating the biting of the foreign object to the user. However, the scope of application of the present invention is not limited to this. Of course, it is possible to employ a configuration without the clarification unit 19, and in such a case, it is also possible to employ a configuration that is not clearly shown to the user.

  In the embodiment described above, the biting determination unit 17 has been described as determining whether or not there is a foreign object bitten based on the discharge pressure. However, the scope of application of the present invention is not limited to this. The biting determination unit 17 may be configured to determine in consideration of the oil temperature. In such a case, it is preferable to provide a temperature detection unit that detects the temperature of the oil.

  In the above-described embodiment, the description has been given on the assumption that the biting determination unit 17 determines whether or not a foreign object is bitten based on the required hydraulic pressure and the discharge pressure. However, the scope of application of the present invention is not limited to this. The biting determination unit 17 may be configured to perform a preliminary determination based on a hydraulic pressure gradient when a predetermined time elapses after the driving force control unit 16 controls the driving force. FIG. 9 shows a diagram illustrating such a form.

  When the driving force input to the operation unit 50 is controlled by the driving force control unit 16, the desired required oil pressure is reached within several tens of milliseconds to several hundreds of milliseconds as described above. Therefore, it is possible to predict in advance the oil pressure gradient at a predetermined time, that is, the amount of change in oil pressure until the oil pressure after a predetermined time has elapsed from the current oil pressure. Such a hydraulic gradient is shown as “normal response” in FIG. On the other hand, if there is a foreign matter bite or some abnormality, the hydraulic gradient changes significantly with respect to the “normal response”. Therefore, the allowable range based on “normal response” is set as “upper limit response” and “lower limit response”, and when the hydraulic gradient exceeds “upper limit response” or lower than “lower limit response”. It is possible to predict in advance that there is a high possibility of an abnormality, and then it is possible to accurately determine whether or not a foreign object is caught by performing the above-described biting determination. In addition, when the determination is performed in a short time, it is possible to determine whether or not a foreign object is caught by only this preliminary determination. In performing such foreign object biting determination, the hydraulic pressure gradient can be calculated by the biting determination unit 17. Further, it is preferable that the reference used for the determination as shown in FIG. 9 is stored in the bite determination unit 17 in advance.

  The above embodiment has been described on the assumption that the required oil pressure is defined in relation to the engine speed. However, the scope of application of the present invention is not limited to this. As a matter of course, it is possible to set the oil temperature, the engine load, the throttle opening degree, and the like according to the engine operating state in addition to the engine speed.

  In the above embodiment, the determination threshold value used by the biting determination unit 17 for biting determination is described as being stored in advance in the form of a map according to the engine speed. However, the scope of application of the present invention is not limited to this. It may be set in advance from the difference between the oil temperature, the required oil pressure and the oil pressure at the start of control, or may be configured to learn with a learning function. It is also possible to set the “upper limit hydraulic pressure” and the “lower limit hydraulic pressure” with different values.

  The present invention can be used for a variable displacement oil pump.

DESCRIPTION OF SYMBOLS 1 Casing 2 Suction port 3 Discharge port 12A External tooth 12 Inner rotor 13 Outer rotor 13A Internal tooth 14 Adjustment ring 16 Driving force control part 17 Engagement determination part 18 Discharge pressure detection part 19 Explicit part 50 Operation part G Guide part X 1st Rotation axis Y Second rotation axis 100 Oil pump

Claims (6)

An inner rotor having a plurality of external teeth and rotating about a first rotation axis;
An outer rotor that is formed in an annular shape having a plurality of internal teeth that mesh with the external teeth, and that rotates according to the rotation of the inner rotor at a second rotational axis that is eccentric with respect to the first rotational axis;
A suction port that supplies oil between the external teeth and the internal teeth, and a discharge port that discharges oil supplied from the suction ports as the inner rotor rotates from between the external teeth and the internal teeth And a casing enclosing the inner rotor and the outer rotor;
An adjustment ring that supports the outer rotor so as to be relatively rotatable from the radially outer side in a state where the outer teeth and the inner teeth mesh with each other;
An operation unit provided on an outer peripheral surface of the adjustment ring, to which a driving force is input;
The adjustment ring is provided on the casing and the adjustment ring, and guides the adjustment ring so that the second rotation axis revolves around the first rotation axis according to a driving force input to the operation unit. A guide part;
A discharge pressure detector that detects the pressure of oil discharged from the discharge port;
A driving force control unit that controls the driving force input to the operation unit such that the pressure of oil discharged from the discharge port becomes a desired required oil pressure;
A biting determination unit that determines whether there is a biting of foreign matter between the casing and the adjustment ring based on the required oil pressure and a detection result of the discharge pressure detection unit;
Oil pump equipped with. The rotational power of the engine is transmitted to the inner rotor,
The oil pump according to claim 1, wherein the required oil pressure is preset according to the rotational speed of the engine. A temperature detection unit for detecting the temperature of the oil;
The oil pump according to claim 1 or 2, wherein the biting determination unit is determined in consideration of the temperature of the oil detected by the temperature detection unit.   The said biting determination part performs preliminary determination based on the hydraulic pressure gradient when the preset predetermined time passes, after the said driving force control part controls the said driving force. Oil pump as described in   5. The drive force control unit according to claim 1, wherein the drive force control unit increases or decreases a drive force input to the operation unit based on a current drive force when it is determined that the foreign object is bitten. 5. The oil pump described.   Even when the driving force control unit increases or decreases the driving force input to the operation unit when it is determined that the foreign matter has been caught, the pressure of the oil discharged from the discharge port is expected. 6. The oil pump according to claim 5, further comprising: an indicating unit that clearly indicates to the user that the foreign matter is bitten when the required oil pressure is not reached.

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