JP2014159757A - Control device for variable displacement oil pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a control device for a variable displacement oil pump, capable of achieving a more appropriate pump discharge oil pressure.SOLUTION: Devices which are provided in an oil supply system for an engine are sorted into a first device group which utilizes oil as operating oil, a second device group for which a required oil pressure depends on an intake air amount and which utilizes oil as cooling agent, and a third device group for which a required oil pressure depends on an engine speed and which utilizes oil as cooling agent and lubricant. The highest required discharge oil pressures are extracted from the devices in each of the device groups, and the highest required discharge oil pressure of them is set as a target discharge oil pressure of an oil pump 5. For example, in the early stage of starting the engine, the required oil pressures for the second device group and the third device group are lower and a relatively low pump discharge pressure enough to meet the required oil pressure for the first device group is required, thus improving the fuel consumption rate of the engine.

Description

  The present invention relates to a control device for a variable displacement oil pump. In particular, the present invention relates to a measure for optimizing pump discharge hydraulic pressure.

  Conventionally, as disclosed in Patent Document 1 and Patent Document 2, in an engine mounted on an automobile or the like, the power of an oil pump (power received from the engine) provided in an oil supply system is suppressed. The target control is performed.

  For example, in Patent Document 1, when the discharge pressure adjusted by the variable displacement oil pump reaches a predetermined pressure, the piston jet is directed toward the back of the piston. The discharge pressure of the oil pump is adjusted according to the engine speed. By doing so, the power required for the oil pump is suppressed. Moreover, in patent document 2, the thermostat opened | released at the time of engine cold is provided in an oil return path | route, and the burden of the oil pump at the time of cold is reduced.

JP 2011-163194 A JP 2007-107485 A

  By the way, the oil supply system is provided with various devices. For example, a device that uses oil as hydraulic oil (for example, a VVT mechanism), a device that uses oil as a coolant (cooling oil) (for example, a piston jet for cooling a piston), and oil as a lubricant (lubricant) There is a device to be used (for example, a journal portion of each shaft).

  The inventors of the present invention have noted that the discharge hydraulic pressure of the oil pump required by these devices and the required timing of the discharge hydraulic pressure are different for each device.

  As a method of individually supplying the hydraulic pressure corresponding to each device, it is possible to provide a switching valve corresponding to each of these devices, and obtain the supply hydraulic pressure individually for each device by the switching operation of these switching valves. Conceivable. However, this is not practical because it complicates the configuration of the oil supply system and complicates the control.

  Therefore, the inventors of the present invention improve the fuel consumption rate of the engine by minimizing the power of the oil pump by comprehensively managing the discharge hydraulic pressure and hydraulic pressure supply timing of the oil pump required by these devices. The present invention has been considered.

  The present invention has been made in view of this point, and an object of the present invention is to provide a control device for a variable displacement oil pump capable of optimizing pump discharge hydraulic pressure.

-Solution principle of the invention-
The solution principle of the present invention taken in order to achieve the above object is that various devices provided in an oil supply system of an internal combustion engine are required to have a high response to the supply oil pressure and a response delay of the supply oil pressure. The oil pressure is separately determined for each of the oil pumps, and the oil pressure is controlled individually so that the highest required oil pressure is set as the target discharge oil pressure. This makes it possible to minimize the power of the oil pump while meeting the requirements of all devices.

-Solution-
Specifically, the present invention is premised on a control device for a variable displacement oil pump that operates by receiving power from an internal combustion engine and includes a variable displacement mechanism. For the control device of the variable displacement oil pump, the hydraulic pressure required for a device that uses oil as hydraulic oil among the devices (components of the oil supply system) provided in the oil supply system of the internal combustion engine, The oil pressure is higher than the oil pressure required for a device that receives heat from combustion in the combustion chamber and uses oil as cooling oil, and generates frictional heat due to sliding, and the oil is used as lubricating oil and cooling oil. The variable capacity mechanism is controlled so that the oil pressure required for the device that uses the oil as hydraulic oil is the oil pump discharge oil pressure when the oil pressure is higher than the oil pressure required for the device to be used.

  In general, when a cold start of an internal combustion engine is performed, an operation of a device that uses oil as hydraulic oil is first required along with the start. For example, a device such as a VVT mechanism may be requested to operate as soon as the internal combustion engine is started. On the other hand, a device (for example, a piston jet) that is heated by receiving heat accompanying combustion in the combustion chamber and uses oil as cooling oil until the amount of heat generated in the combustion chamber of the internal combustion engine reaches a predetermined amount. Does not require cooling. Further, a device that generates frictional heat due to sliding and uses oil as lubricating oil and cooling oil (for example, a crankshaft journal) does not require lubrication or cooling until the rotational speed of the internal combustion engine reaches a predetermined value. . In other words, the hydraulic pressure required for these devices (devices that use oil as cooling oil and devices that use oil as lubricating oil and cooling oil) is the hydraulic pressure required for devices that use oil as hydraulic oil. This request is delayed.

  Therefore, at the initial cold start of the internal combustion engine, the oil pressure required for the device that uses oil as the working oil is higher than the oil pressure required for the device that uses the oil as the cooling oil, and the oil It becomes a situation higher than the hydraulic pressure required for a device using the oil as a lubricating oil and a cooling oil. In this case, in this solution, the variable capacity mechanism is controlled so that the oil pressure required for the device that uses oil as hydraulic oil is the oil pump discharge oil pressure. In other words, only the hydraulic pressure required for a device that uses oil as hydraulic oil is taken into consideration, and the oil pump discharge hydraulic pressure (the hydraulic pressure required to operate a device such as a VVT mechanism) is set to a relatively low level. It will be. For this reason, the oil pump discharge hydraulic pressure is not set higher than necessary, the power of the oil pump can be suppressed to the minimum necessary, and the fuel consumption rate of the internal combustion engine can be improved.

  In the above description, the initial cold start time of the internal combustion engine is taken as an example, but in other periods, the hydraulic pressure required for a device that uses oil as hydraulic oil is higher than the hydraulic pressure required for other devices. The same control is performed when the situation becomes high.

  Also, the oil pressure required for the device that uses the oil as hydraulic oil is lower than the oil pressure required for the device that uses oil as cooling oil, and the device that uses the oil as lubricating oil and cooling oil is required. When the oil pressure is lower than the oil pressure, the oil pressure required for the device that uses the oil as a lubricating oil and the oil pressure required for the device that uses the oil as a lubricating oil and a cooling oil are higher. The variable capacity mechanism is controlled to have a pump discharge hydraulic pressure.

  When the amount of heat generated in the combustion chamber of the internal combustion engine reaches a predetermined amount or the rotational speed of the internal combustion engine reaches a predetermined value due to completion of the warm-up operation of the internal combustion engine, the oil is used as cooling oil. The oil pressure required for devices and the oil pressure required for devices that use oil as lubricating oil and cooling oil are high, and the oil pressure required for devices that use oil as hydraulic oil is lower than these oil pressures. . In this case, in this solution, a higher hydraulic pressure is required among a hydraulic pressure required for a device using oil as a lubricating oil and a hydraulic pressure required for a device using oil as a lubricating oil and a cooling oil. Therefore, the variable capacity mechanism is controlled so as to obtain the oil pump discharge hydraulic pressure. For this reason, it is possible to minimize the power of the oil pump while satisfying the requirements (required hydraulic pressure) of all devices, so that the performance, lubrication and cooling requirements of each device can be met. Ensuring and improving the fuel consumption rate of the internal combustion engine can be combined.

  Specific examples of the configuration for calculating the hydraulic pressure required for a device that uses the oil as cooling oil include the following. That is, the hydraulic pressure required for a device that uses the oil as cooling oil is calculated according to the operating state of the internal combustion engine. The followability of the calculated hydraulic pressure with respect to the change in the operating state of the internal combustion engine is set higher as the amount of heat generated by combustion in the combustion chamber of the internal combustion engine increases.

  According to this configuration, when the amount of heat generated by combustion in the combustion chamber rapidly increases, the hydraulic pressure required for a device that uses oil as cooling oil is calculated as a high value with high followability. It will be. For this reason, in a situation where the hydraulic pressure required for this device (a device that uses oil as cooling oil) is higher than the hydraulic pressure required for other devices, this device should be cooled well. And heat damage to the device can be prevented. On the other hand, when the amount of heat generated by combustion in the combustion chamber is small, followability is lowered as a hydraulic pressure required for a device that uses oil as cooling oil. That is, the amount of increase in hydraulic pressure required for the device is made relatively low with respect to the amount of increase in heat generated by combustion in the combustion chamber. When the calorific value rises from such a situation where the calorific value due to combustion in the combustion chamber is small, the timing of occurrence of the cooling performance required for cooling the device that uses oil as cooling oil is determined by this device. It is delayed by a period until it is heated to a temperature (temperature at which cooling is required). For this reason, in such a situation, by reducing the follow-up performance of the hydraulic pressure, it is possible to set the necessary minimum hydraulic pressure (minimum required hydraulic pressure to satisfy the current cooling performance). Is not wasted by the oil pump. For example, the oil pressure required for this device (a device that uses oil as cooling oil) can be delayed from exceeding the oil pressure required for another device (for example, a device that uses oil as hydraulic oil) The oil pump discharge hydraulic pressure can be changed in a low state, and the fuel consumption rate of the internal combustion engine can be improved. Further, in a situation where the amount of heat generated by combustion in the combustion chamber temporarily increases, it is not necessary to increase the oil pump discharge hydraulic pressure accordingly. Even in such a case, the followability of the hydraulic pressure is set to be low (followup is set to be low due to the subsequent decrease in the amount of heat generation), and thus the power of the internal combustion engine is wasted by the oil pump. Nothing will happen.

  Specific examples of the configuration for calculating the hydraulic pressure required for a device that uses the oil as a lubricating oil and a cooling oil include the following. That is, the hydraulic pressure required for a device that uses the oil as lubricating oil and cooling oil is calculated according to the operating state of the internal combustion engine. The followability of the calculated hydraulic pressure with respect to the change in the operating state of the internal combustion engine is set higher as the rotational speed of the internal combustion engine is higher.

  According to this configuration, when the rotational speed of the internal combustion engine increases rapidly, the hydraulic pressure required for a device that uses oil as lubricating oil and cooling oil is calculated as a high value with high followability. It will be. Therefore, in a situation where the hydraulic pressure required for this device (a device that uses oil as lubricating oil and cooling oil) is higher than the hydraulic pressure required for other devices, Can be lubricated and cooled. On the other hand, when the rotational speed of the internal combustion engine is low, followability is lowered as a hydraulic pressure required for a device that uses oil as lubricating oil and cooling oil. That is, the amount of increase in hydraulic pressure required for the device is relatively low with respect to the amount of increase in the rotational speed of the internal combustion engine. When the engine speed increases from such a low engine speed, the lubrication performance required for lubrication of the device that uses oil as the lubricating oil and cooling oil and the cooling performance required for cooling are required. The generation time of is delayed by a period until the relative speed of the sliding portion of the device reaches a predetermined speed (speed at which lubrication or cooling is required). For this reason, by reducing the follow-up performance of the hydraulic pressure in such a situation, it is possible to set the required minimum hydraulic pressure (the minimum required hydraulic pressure to satisfy the current lubrication performance and cooling performance). The engine power is not wasted by the oil pump. For example, delaying the hydraulic pressure required for this device (a device that uses oil as lubricant and cooling oil) from exceeding the hydraulic pressure required for other devices (eg, a device that uses oil as hydraulic fluid) Thus, the oil pump discharge hydraulic pressure can be changed in a low state, and the fuel consumption rate of the internal combustion engine can be improved. Further, in a situation where the rotational speed of the internal combustion engine temporarily increases, it is not necessary to increase the oil pump discharge hydraulic pressure accordingly. Even in such a case, the followability of the hydraulic pressure is set to be low (followability is set to be low due to the subsequent decrease in the rotational speed), so that the power of the internal combustion engine is wasted by the oil pump. Nothing will happen.

  Specific examples of each device include the following. First, a plurality of devices that use the oil as hydraulic oil are defined as a first device group, and the highest hydraulic pressure required for each of the plurality of devices is the hydraulic pressure required for the first device group. The oil pressure required for a device that uses the oil as a cooling oil and the oil pressure required for a device that uses the oil as a lubricating oil and a cooling oil are compared.

  In this case, a device that uses the oil as hydraulic oil includes a variable valve timing mechanism and a chain tensioner.

  In addition, a plurality of devices that use the oil as cooling oil are defined as a second device group, and the highest hydraulic pressure required for each of the plurality of devices is the hydraulic pressure required for the second device group. The hydraulic pressure required for a device that uses the oil as hydraulic oil and the hydraulic pressure required for a device that uses the oil as lubricating oil and cooling oil are compared.

  In this case, examples of a device that uses the oil as cooling oil include a turbo shaft of a turbocharger and an oil jet for cooling a piston.

  Further, a plurality of devices that use the oil as lubricating oil and cooling oil are defined as a third device group, and the highest hydraulic pressure required for each of the plurality of devices is required for the third device group. The oil pressure is represented by a hydraulic pressure required for a device that uses the oil as hydraulic oil, and a hydraulic pressure required for a device that uses the oil as hydraulic oil.

  In this case, examples of devices that use the oil as lubricating oil and cooling oil include a crankshaft journal and a camshaft journal.

  As described above, multiple devices are defined as a device group, and the comparison of the representative value of the hydraulic pressure required for that device group with the hydraulic pressure required for other devices makes this comparison operation simple. Can be achieved.

  In the present invention, the required oil pressure is individually determined for each device provided in the oil supply system of the internal combustion engine, and the oil pump is controlled so that the highest required oil pressure is the target discharge oil pressure. This makes it possible to minimize the power of the oil pump while satisfying the requirements of all devices.

It is a schematic block diagram which shows the oil supply system of the engine which concerns on embodiment. It is sectional drawing which shows the structure of an oil pump, Comprising: It is a figure which shows a pump capacity | capacitance in the maximum state. It is sectional drawing which shows the structure of an oil pump, Comprising: It is a figure which shows a pump capacity | capacitance in the minimum state. It is a block diagram which shows schematic structure of a control system. It is a conceptual diagram of the operation | movement which determines the target discharge hydraulic pressure of an oil pump. It is a flowchart figure which shows the procedure of pump capacity | capacitance control. FIG. 7A shows an example of the relationship between the engine speed, the VVT mechanism required oil pressure, and the chain tensioner required oil pressure, and FIG. 7B shows the relationship between the engine load, the piston cooling required oil pressure, and the turbocharger cooling required oil pressure. FIG. 7C is a diagram showing an example of the relationship between the engine speed, the crankshaft journal required hydraulic pressure, and the camshaft journal required hydraulic pressure. It is a figure which shows an example of transition of the target discharge oil_pressure | hydraulic of an oil pump with a raise of engine speed or engine load.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. This embodiment demonstrates the case where this invention is applied to the variable displacement oil pump with which the oil supply system of the gasoline engine (internal combustion engine) for motor vehicles was equipped.

-Oil supply system-
FIG. 1 is a schematic configuration diagram illustrating an oil supply system of an engine according to the embodiment. As shown in FIG. 1, in an oil supply system, oil stored in an oil pan 10 provided at the lower part of a cylinder block is pumped up by an oil pump 5 and each device (a device that uses oil as hydraulic oil, oil Is supplied to a device that uses oil as a coolant (cooling oil), and a device that uses oil as a lubricant (lubricating oil), and then is recovered by the oil pan 10.

  Specifically, the oil stored in the oil pan 10 is pumped up to the oil pump 5 through an oil strainer 11a for removing foreign matter. The oil pump 5 is operated by engine power (crankshaft rotational power) and pressurizes and discharges oil. The oil pump 5 is a variable displacement oil pump. A specific configuration of the oil pump 5 will be described later.

  The oil discharged from the oil pump 5 is cooled by the oil cooler 11b and then filtered by the oil filter 11c.

  The oil that has passed through the oil filter 11c is supplied to the main oil hole 20 formed in the cylinder block. The main oil hole 20 extends toward various parts (each device) in the engine. This will be specifically described below. In addition, since the specific structure of each device described below is well-known, description here is abbreviate | omitted.

  Part of the oil that has flowed through the main oil hole 20 is supplied to the chain tensioner 12 and used as hydraulic oil for the chain tensioner 12. That is, the tension of the timing chain is adjusted by the hydraulic pressure supplied to the chain tensioner 12.

  Part of the oil that has passed through the main oil hole 20 flows inside the cylinder head 13, and part of the oil lubricates and cools a camshaft journal (camshaft bearing portion) 13a provided in the cylinder head 13. To do. Part of the oil that has lubricated and cooled the camshaft journal 13 a is returned to the oil pan 10. Further, another part of the oil that has lubricated and cooled the camshaft journal 13a is returned to the oil pan 10 after lubricating the rocker arm (sliding portion of the rocker arm) 13b and the like.

  The other part of the oil that has flowed through the cylinder head 13 is used as hydraulic oil for a variable valve timing (VVT) mechanism 13c. Specifically, the supply of hydraulic oil to the VVT mechanism 13c is controlled by a hydraulic control valve (OCV) 13d, and the supplied oil is discharged from the VVT mechanism 13c or the amount of oil to be supplied to the VVT mechanism 13c is determined. Excess excess oil is returned to the oil pan 10 from the OCV 13d.

  Part of the oil that has passed through the main oil hole 20 is sent to the oil jet 14a. The oil from the oil jet 14a is ejected toward the back surface of the piston 14b, whereby the piston 14b is cooled. The oil ejected to the piston 14b is returned to the oil pan 10.

  A part of the oil that has passed through the main oil hole 20 is supplied to a crankshaft journal (bearing portion of the crankshaft) 15a and a timing chain 15c. The oil supplied to the crankshaft journal 15a lubricates and cools the crankshaft journal 15a and is guided to a connecting rod (sliding portion of the connecting rod) 15b. The oil that has lubricated and cooled the connecting rod 15 b is returned to the oil pan 10. Also, the oil supplied to the timing chain 15c lubricates the timing chain 15c and returns to the oil pan 10.

  Further, part of the oil that has passed through the main oil hole 20 cools the turbocharger 16. Specifically, the turbo shaft of the turbocharger 16 whose temperature has risen due to the heat of the exhaust gas is cooled. The oil that has passed through the turbocharger 16 is returned to the oil pan 10.

  The above oil circulation operation is performed in the oil supply system.

-Structure of oil pump-
Next, the structure of the oil pump 5 will be described in detail with reference to FIG. The oil pump 5 includes an external gear drive rotor 51 that is rotated by an input shaft 5a, an internal gear driven rotor 52 that is meshed with the drive rotor 51, and an adjustment ring 53 that rotatably holds the driven rotor 52 from the outer periphery. (Holding member) is housed in a housing 50 (pump housing). The adjustment ring 53 is also a capacity adjustment member that changes the pump capacity by displacing the drive rotor 51 and the driven rotor 52 as described later.

  The housing 50 has a thick plate shape as a whole, and has a long oval shape when viewed from the rear of the engine as shown in FIG. 2, and has a protruding portion 50a from the upper right to the right in the figure. From the lower left part of the figure, a protrusion 50b is formed downward. In addition, a recess 50c is formed in the entire housing 50 so as to open rearward, that is, toward the inside of the engine (front side in the figure).

  The recess 50c accommodates the drive rotor 51, the driven rotor 52, the adjustment ring 53, and the like (hereinafter referred to as an accommodation recess 50c), and is closed by a cover (not shown) superimposed on the housing 50 from the rear. . Further, a through hole (not shown) having a circular cross section is formed at a position slightly to the right of the center of the housing recess 50 c, and the input shaft 5 a inserted through the through hole projects forward from the housing 50.

  Thus, a pump sprocket to which the rotational power of the crankshaft is transmitted via the chain is attached to the front end portion of the input shaft 5a protruding forward of the housing 50. On the other hand, the rear end portion of the input shaft 5a passes through the center portion of the drive rotor 51 and is fitted by, for example, a spline. The drive rotor 51 has a plurality of outer teeth 51a (11 in the example shown in the figure) having a trochoid curve or a curve approximated to a trochoid curve (for example, involute, cycloid, etc.) on the outer periphery.

  On the other hand, the driven rotor 52 is formed in an annular shape, and has inner teeth 52a that are one tooth larger than the inner teeth 52a (12 in the example shown in the figure) so as to mesh with the outer teeth 51a of the drive rotor 51. Is formed. The center of the driven rotor 52 is eccentric by a predetermined amount with respect to the center of the drive rotor 51, and the outer teeth 51 a of the drive rotor 51 and the inner teeth 52 a of the driven rotor 52 on the eccentric side (the upper left side in FIG. 2). Are engaged.

  The driven rotor 52 is slidably fitted and supported by an annular main body 53 a of the adjustment ring 53. In this example, the adjustment ring 53 has two projecting portions 53b and 53c projecting radially outward from the outer periphery of the main body 53a in the circumferential direction over a predetermined angular range (about 50 ° in the example in the figure). In addition, an arm portion 53d extending greatly outward in the radial direction and a small protruding portion 53e are integrally formed. Details of the adjustment ring 53 will be described later.

  In this embodiment, a trochoid pump having 11 leaves and 12 nodes is configured by the drive rotor 51 and the driven rotor 52 held in the adjustment ring 53 in this manner, and the annular space between the two rotors 51 and 52 is formed in the annular space. Are formed with a plurality of working chambers R arranged in the circumferential direction between teeth engaged with each other. The volume of each working chamber R increases or decreases while moving along the outer periphery of the drive rotor 51 as the two rotors 51 and 52 rotate.

  That is, in a range extending from the position where the teeth of the two rotors 51 and 52 mesh with each other to about 180 degrees in the rotor rotation direction indicated by the arrow in the drawing (the lower left side range in FIG. 2), the two rotors 51 and 52 rotate. Accordingly, the volume of the working chamber R gradually increases, and an intake range for sucking oil is obtained. On the other hand, in the remaining range of about 180 degrees (the upper right side range in FIG. 2), the volume of the working chamber R gradually decreases as the rotors 51 and 52 rotate, and the oil is discharged while being pressurized. The discharge range.

  A suction port and a discharge port are formed in the housing 50 and the cover so as to correspond to the suction range and the discharge range, respectively. Although only the suction port 50d and the discharge port 50e of the housing 50 are shown in FIG. 2, the suction port 50d is opened on the bottom surface of the housing recess 50c of the housing 50 so as to correspond to the suction region. The discharge port 50e is opened so as to correspond.

  The suction port 50d is located on the lower left side of the housing 50 in the drawing and communicates with a suction port of a cover (not shown), and communicates with the suction conduit of the oil strainer 11a through this. On the other hand, the discharge port 50e is located on the upper right side of the housing 50, communicates with a discharge port of a cover (not shown), and extends toward the right side of the drawing so as to correspond to the protruding portion 50a of the housing 50. It reaches the communication path 6a toward the cooler 11b.

  With this configuration, when the input shaft 5a rotates in response to the force from the crankshaft transmitted to the pump sprocket, the oil pump 5 rotates while the drive rotor 51 and the driven rotor 52 mesh with each other, and is formed between them. Oil is sucked into the working chamber R from the suction port 50d, pressurized, and discharged from the discharge port 50e.

(Capacity variable mechanism)
The oil pump 5 of the present embodiment includes a variable capacity mechanism capable of changing the amount of oil discharged per rotation of the drive rotor 51, that is, the pump capacity. In the present embodiment, the adjustment ring 53 is displaced mainly by the hydraulic pressure (discharge pressure) guided from the discharge port 50e, and the relative positions of the drive rotor 51 and the driven rotor 52 with respect to the suction port 50d and the discharge port 50e. By changing the flow rate of the oil sucked and discharged per one rotation.

  Specifically, as shown in FIG. 2, a pressing force from the compression coil spring 54 acts on the arm portion 53d extending radially outward from the main body portion 53a of the adjustment ring 53, whereby the adjustment ring 53 53 is urged so as to be slightly displaced upward while rotating clockwise in the figure. Further, the adjustment ring 53 is guided by the guide pins 55 and 56 during such displacement.

  That is, the projecting portions 53 b and 53 c of the adjustment ring 53 are each formed in a curved elliptical frame shape, and accommodate the guide pins 55 and 56 projecting from the bottom surface of the housing recess 50 c of the housing 50. These guide pins 55 and 56 are in contact with the inner circumferences of the frame-like projecting portions 53b and 53c, respectively, and slide in the longitudinal direction thereof, whereby the locus of displacement of the adjustment ring 53 is defined. The

  The adjusting ring 53 that is displaced by being guided by the guide pins 55 and 56 in this way divides the inside of the accommodating recess 50c into a high-pressure space TH on the upper right side in the drawing and a low-pressure space TL from the left side to the lower side. It is operated in response to the hydraulic pressure. That is, the high-pressure space TH is surrounded by the outer periphery of the protruding portion 53 c of the adjustment ring 53 and the wall portion of the housing 50 in the housing recess 50 c of the housing 50, and the first and second sealing members 57 and 58. Is formed in a region where the flow of oil is restricted.

  A part of the opening of the discharge port 50 e faces the high pressure space TH, and the discharge pressure of the oil pump 5 is guided to the high pressure space TH and acts on the outer peripheral surface of the adjustment ring 53. On the other hand, since the atmospheric pressure is generally applied to the low pressure space TL that communicates with the suction port 50d, the adjustment ring 53 is rotated counterclockwise in the figure by the hydraulic pressure from the high pressure space TH. Will be energized.

  On the other hand, the adjustment ring 53 is biased in the clockwise direction by receiving the elastic force of the coil spring 54 acting on the arm portion 53d as described above, and is mainly displaced by the biasing force.

  Further, in the present embodiment, as shown in FIG. 2 (state where the pump capacity is maximum) and FIG. 3 (state where the pump capacity is minimum), the control space TC is adjacent to the high-pressure space TH in the housing 50. A (hydraulic chamber) is provided, and a control oil pressure is supplied from an electronically controlled control valve 60 (hereinafter referred to as OCV) to generate a force that assists the displacement of the adjustment ring 53. By adjusting the control oil pressure with the OCV 60 with high accuracy and adjusting the magnitude of the force that assists the displacement of the adjustment ring 53, the controllability of the pump capacity is enhanced.

  Specifically, a second sealing member 58 is disposed on the outer periphery of the adjusting ring 53 at approximately the middle between the two projecting portions 53b and 53c, and the inner surface of the wall portion of the housing 50 surrounding the housing recess 50c. It comes in sliding contact. The second seal material 58 is a seal portion between the high-pressure space TH and the control space TC, and moves along the inner surface of the wall portion of the housing 50 in accordance with the displacement of the adjustment ring 53 as described above. Become.

  Similarly, a third seal material 59 is disposed at the tip of the arm portion 53d of the adjustment ring 53 so as to be in sliding contact with the inner surface of the wall portion of the housing 50 facing the adjustment ring 53. The second and third sealing materials 58 and 59 and the first sealing material 57 described above both have the thickness of the adjustment ring 53 (the dimension in the direction perpendicular to the paper surface of FIGS. 2 and 3). It is formed of a metal material or resin material having the same size and excellent wear resistance.

  Thus, the control space TC is surrounded by the outer periphery of the adjustment ring 53 (specifically, the outer periphery of the projecting portion 53b), the arm portion 53d, and the wall portion of the housing 50 facing them in the housing recess 50c of the housing 50, In addition, the second and third seal members 58 and 59 are formed in a region where the oil flow is restricted. Then, the control oil pressure is supplied from the OCV 60 through the control oil passage 61 that opens to the bottom surface of the housing recess 50c in the control space TC.

  That is, one end of the control oil passage 61 opens as the round hole 61a facing the control space TC as described above, and the other end communicates with the control port 60a of the OCV 60. The OCV 60 receives a signal from the ECU 100 (see FIG. 4), which will be described later, the spool position is changed, and the oil from the supply port 60b is sent from the control port 60a to the control oil passage 61. The discharged oil is received by the control port 60a and switched to a state of discharging from the drain port 60c.

  Further, as an example, in the OCV 60 that is a linear solenoid valve, the position of the spool continuously changes in response to a signal (Duty signal) from the ECU 100, and the pressure of oil sent from the control port 60a to the control oil passage 61 as described above. Can be increased or decreased linearly. Therefore, for example, when the adjustment ring 53 is displaced in the counterclockwise direction of FIG. 2 as the engine speed increases as described above, the control hydraulic pressure supplied to the control space TC is increased to reduce the displacement of the adjustment ring 53. Can assist.

  On the other hand, if the control hydraulic pressure supplied to the control space TC is reduced by the control of the OCV 60, the displacement of the adjustment ring 53 in the counterclockwise direction can be suppressed. This improves the controllability of the pump capacity. As shown in FIGS. 2 and 3, in this embodiment, the branch path 6b is connected in the middle of the communication path 6a from the discharge port 50e of the oil pump 5 to the oil cooler 11b to supply oil to the OCV 60. However, the present invention is not limited to this. For example, the oil filtered by the oil filter 11c may be supplied to the OCV 60.

-Control system-
FIG. 4 is a block diagram showing a schematic configuration of a control system in the engine. As shown in FIG. 4, the ECU 100 includes a CPU 101, a ROM 102, a RAM 103, a backup RAM 104, and the like. The ROM 102 stores various control programs, maps that are referred to when the various control programs are executed, and the like. The CPU 101 executes arithmetic processing based on various control programs and maps stored in the ROM 102. The RAM 103 is a memory that temporarily stores calculation results from the CPU 101, data input from each sensor, and the backup RAM 104 is a non-volatile memory that stores data to be saved when the engine is stopped. . These ROM 102, CPU 101, RAM 103, and backup RAM 104 are connected to each other via a bus 107, and are connected to an input interface 105 and an output interface 106.

The input interface 105 includes a water temperature sensor 110 for detecting the coolant temperature of the engine, an air flow meter 111 for measuring the intake air amount, an intake air temperature sensor 112 for measuring the intake air temperature, an O ₂ sensor 113 provided in the exhaust system, An accelerator position sensor 114 that detects the accelerator opening, a throttle position sensor 115 that detects the opening of the throttle valve, a crank position sensor 116 that detects the rotational position of the crankshaft, a cam position sensor 117 that detects the rotational position of the camshaft, An oil pressure sensor 118 that is disposed in the main oil hole 20 and detects the oil pressure in the main oil hole 20, and an oil temperature sensor that is disposed in the main oil hole 20 and detects the oil temperature in the main oil hole 20. Various sensors such as 119 It has been continued.

  Connected to the output interface 106 are an injector 7, an ignition plug igniter 8, a throttle valve throttle motor 9, the OCV 60 that controls the discharge hydraulic pressure of the oil pump 5, and the like. The ECU 100 executes various engine controls including fuel injection control of the injector 7, ignition timing control of the ignition plug, throttle valve opening control, and the like based on the detection signals of the various sensors described above.

  Then, the ECU 100 adjusts the pump capacity of the oil pump 5 according to the operating state of the engine and the like, and executes the following pump capacity control for controlling the discharge hydraulic pressure from the oil pump 5.

-Pump capacity control-
Hereinafter, the pump displacement control characteristic in the present embodiment will be described. First, an outline of the pump displacement control will be described.

  Ensuring the hydraulic oil pressure for operating the VVT mechanism 13c and the chain tensioner 12, ensuring the cooling performance required for cooling the turbocharger 16 and the piston 14b, and the crankshaft journal 15a and camshaft In order to improve the fuel consumption rate of the engine while ensuring the cooling performance and lubrication performance required for cooling and lubricating the journal 13a, the discharge hydraulic pressure and power of the oil pump 5 (the operation of the oil pump 5) It is effective to minimize the power required for

  However, until now, each of these multiple devices (devices that use oil as hydraulic oil, devices that use oil as a coolant (cooling oil), devices that use oil as a lubricant (lubricating oil) and coolant), respectively. There have been no proposals for comprehensively managing the required oil pump discharge hydraulic pressure and hydraulic pressure supply timing to minimize the oil pump power and thereby improving the fuel consumption rate of the engine. For this reason, in the prior art, the engine power may be wasted by the oil pump, leading to a deterioration in the fuel consumption rate.

  In view of this point, the present embodiment first obtains the required discharge hydraulic pressure and hydraulic pressure supply timing of the oil pump 5 for each device. Specifically, the plurality of devices are heated by receiving heat accompanying combustion in the combustion chamber in the first device group that is a set of a plurality of devices that use oil as hydraulic oil, and the oil is cooled. A second device group that is a set of a plurality of devices used as a coolant (cooling oil), and a set of devices that generate frictional heat due to sliding and use oil as a coolant and lubricant (lubricant) Grouped into a certain third device group. An oil pump discharge hydraulic pressure currently requested by the first device group (hereinafter sometimes simply referred to as a required hydraulic pressure), an oil pump discharge hydraulic pressure currently requested by the second device group, and a third The oil pump discharge hydraulic pressure currently requested by the device group is compared, the highest oil pump discharge hydraulic pressure among them is determined as the current target discharge hydraulic pressure, and the oil pump 5 is set so as to obtain this target discharge hydraulic pressure. Perform pump capacity control. Specifically, the pump displacement is adjusted by controlling the displacement variable mechanism.

  For example, the required oil pressure of the first device group (device group that uses oil as hydraulic oil) is higher than the required oil pressure of the second device group (device group that uses oil as a coolant), and the third In the situation where the required oil pressure of the device group (device group using oil as a coolant and lubricant) is higher than the required oil pressure of the first device group, the variable capacity mechanism is controlled. Yes. That is, the displacement variable mechanism is controlled so that the oil pressure required for the first device group is the discharge oil pressure of the oil pump 5.

  Further, in the present embodiment, when determining the oil pump discharge hydraulic pressure required by the second device group and the oil pump discharge hydraulic pressure required by the third device group, the dependency parameter for each device group is determined. Response delay control using a time constant according to (physical quantity such as engine load (intake air quantity) and engine speed) is performed. This response delay control will be described later.

  FIG. 5 is a conceptual diagram of an operation for determining the target discharge hydraulic pressure of the oil pump 5. In FIG. 5, the VVT mechanism 13c and the chain tensioner 12 are listed as the devices of the first device group. Further, the turbocharger 16 and the piston 14b are cited as devices of the second device group. Furthermore, a crankshaft journal 15a and a camshaft journal 13a are listed as devices of the third device group.

  Then, the pump discharge hydraulic pressure required by each device 13c, 12 of the first device group is input to the first comparator 201, and the highest pump discharge hydraulic pressure among the pump discharge hydraulic pressures is input to the required discharge of the first device group. Output as hydraulic pressure. In addition, the pump discharge hydraulic pressure required by each device 16 and 14b of the second device group is input to the second comparator 202, and the highest pump discharge hydraulic pressure among the pump discharge hydraulic pressures is input to the required discharge of the second device group. Output as hydraulic pressure. Further, the pump discharge hydraulic pressure required by each of the devices 15a and 13a of the third device group is input to the third comparator 203, and the highest pump discharge hydraulic pressure among them is supplied to the required discharge of the third device group. Output as hydraulic pressure.

  Then, these required discharge hydraulic pressures are input to the fourth comparator 204, the required discharge hydraulic pressure of the first device group, the required discharge hydraulic pressure of the second device group (the required discharge hydraulic pressure obtained by response delay control), the first The required discharge hydraulic pressure of the device group 3 (required discharge hydraulic pressure obtained by response delay control) is compared, and the highest required discharge hydraulic pressure is determined as the target discharge hydraulic pressure of the oil pump 5. The displacement variable mechanism is controlled according to the determined target discharge hydraulic pressure, and the pump displacement is adjusted so as to obtain the target discharge hydraulic pressure.

  Next, the pump displacement control will be specifically described with reference to the flowchart of FIG. The flowchart shown in FIG. 6 is executed every several milliseconds during the operation of the engine.

  First, in step ST1, information from each sensor is acquired. Specifically, the rotational position information of the crankshaft from the crank position sensor 116, the accelerator opening information from the accelerator position sensor 114, the intake air amount information from the air flow meter 111, and the like are acquired.

  Thereafter, the process proceeds to step ST2, and the required discharge hydraulic pressure of the first device group is extracted. Specifically, the pump discharge hydraulic pressure (required hydraulic pressure) required by each device in the first device group is compared, and the highest pump discharge hydraulic pressure is extracted. FIG. 7A shows an example of a change in the required oil pressure of the first device group accompanying an increase in the engine speed. A solid line in the figure represents a change in pump discharge hydraulic pressure (required hydraulic pressure) required for the VVT mechanism 13c among the devices in the first device group, and a broken line in the figure represents a chain among the devices in the first device group. This is a change in pump discharge hydraulic pressure required for the tensioner 12. Note that these required oil pressures are obtained as values obtained by correcting the required minimum oil pressure of each device obtained by experiments and simulations by a predetermined amount to increase correction (increasing correction considering the safety factor).

  In the case shown in FIG. 7A, the pump discharge hydraulic pressure required for the VVT mechanism 13c is higher than the pump discharge hydraulic pressure required for the chain tensioner 12, so this first device group. As the required discharge hydraulic pressure, the pump discharge hydraulic pressure required for the VVT mechanism 13c is extracted.

  When the pump discharge hydraulic pressure required for the chain tensioner 12 is higher than the pump discharge hydraulic pressure required for the VVT mechanism 13c, the chain tensioner 12 is used as the required discharge hydraulic pressure for the first device group. Therefore, the pump discharge hydraulic pressure required is extracted. Further, when the pump discharge hydraulic pressure on the higher side switches between the pump discharge hydraulic pressure required for the VVT mechanism 13c and the pump discharge hydraulic pressure required for the chain tensioner 12 as the engine speed increases, The higher pump discharge hydraulic pressure is extracted at the engine speed.

  Each device in the first device group is a device that uses oil as hydraulic oil, and therefore, hydraulic pressure for operating these devices is required almost simultaneously with the start of the engine. In other words, the valve timing adjustment operation by the VVT mechanism 13c and the timing chain tension adjustment operation by the chain tensioner 12 are required substantially simultaneously with the start of the engine, and the hydraulic pressure supplied to these devices increases with the start of the engine. Immediately required. That is, each device of the first device group can be called an engine start immediate hydraulic pressure request device.

  After extracting the required discharge hydraulic pressure of the first device group, the process proceeds to step ST3, and the required discharge hydraulic pressure of the second device group is extracted. Specifically, the pump discharge hydraulic pressure (required hydraulic pressure) required by each device in the second device group is compared, and the highest pump discharge hydraulic pressure is extracted. FIG. 7B shows an example of a change in the required hydraulic pressure of the second device group accompanying an increase in engine load. The solid line in the figure is the change in pump discharge hydraulic pressure required for the piston 14b (required for cooling the piston 14b) among the devices of the second device group, and the broken line in the figure is the second device group. This is a change in pump discharge hydraulic pressure required for the turbocharger 16 (required for cooling the turbo shaft) of each device.

  As described above, the pump discharge hydraulic pressure required for each device in the second device group depends on the engine load (in other words, the intake air amount), and each device in the second device group corresponds to the engine load. It can be referred to as an (intake air amount) dependent hydraulic pressure request device. Note that these required oil pressures are obtained as values obtained by correcting the required minimum oil pressure of each device obtained by experiments and simulations by a predetermined amount to increase correction (increasing correction considering the safety factor).

  In the case shown in FIG. 7 (b), the pump discharge hydraulic pressure required for the piston 14b is higher than the pump discharge hydraulic pressure required for the turbocharger 16. Therefore, the second device group is required. As the discharge hydraulic pressure, the pump discharge hydraulic pressure required for the piston 14b is extracted.

  When the pump discharge hydraulic pressure required for the turbocharger 16 is higher than the pump discharge hydraulic pressure required for the piston 14b, the required discharge hydraulic pressure for the second device group is the turbocharger 16 The required pump discharge hydraulic pressure is extracted. Furthermore, when the pump discharge hydraulic pressure on the higher side is switched between the pump discharge hydraulic pressure required for the piston 14b and the pump discharge hydraulic pressure required for the turbocharger 16 as the engine load increases, the current engine The pump discharge hydraulic pressure on the higher side in the load is extracted.

  Since each device of the second device group is a device that uses oil as a coolant, the device is heated to a predetermined temperature (a temperature that requires cooling) until a predetermined time elapses after the engine is started. The request is delayed.

  In the present embodiment, response delay control is executed when extracting the required discharge hydraulic pressure of the second device group. This response delay control is performed when the engine load temporarily increases, that is, when the engine load decreases again after the engine load increases temporarily, the pump discharge corresponding to the temporary increase in engine load is performed. It is considered in view of the fact that it is not necessary to increase the hydraulic pressure (the pump discharge hydraulic pressure does not need to increase because the temperature of the device does not increase suddenly when the engine load temporarily increases). That is, the control is performed to increase the required discharge hydraulic pressure in response to the increase in the engine load only when the engine load has increased for a predetermined time. That is, this response delay control is to calculate the required discharge hydraulic pressure so that the required discharge hydraulic pressure of the second device group is increased when the engine load is high for a predetermined time. In the invention, “corresponding to the change in the operating state of the internal combustion engine at the calculated hydraulic pressure is set higher as the amount of heat generated by combustion in the combustion chamber of the internal combustion engine is larger”). Specifically, for example, by appropriately setting a time constant in the following equation (1), the response of the required discharge hydraulic pressure in accordance with the fluctuation of the engine load is adjusted.

Required discharge hydraulic pressure = previous value of required discharge hydraulic pressure +
{(Required discharge oil pressure map value−Previous value of requested discharge oil pressure) / Time constant} (1)
Here, the previous value of the required discharge hydraulic pressure corresponds to the required discharge hydraulic pressure calculated in step ST3 in the previous routine. The required discharge hydraulic pressure map value is a required discharge hydraulic pressure value read from a map stored in advance in the ROM 102 in order to extract the required discharge hydraulic pressure according to the engine load. This map is created in advance based on experiments and simulations.

  The time constant is changed according to the engine load. The larger the engine load, the smaller the time constant is set, and the larger the amount of change in the required discharge hydraulic pressure obtained by the equation (1). It has come to be obtained. For this reason, when the engine load temporarily increases, the time constant temporarily decreases in the direction of decreasing, but as the engine load subsequently decreases, the time constant increases and the required discharge hydraulic pressure increases. (The responsiveness to the side where the required discharge hydraulic pressure increases is reduced). As a result, unless the state where the engine load becomes high continues, the increase in the required discharge hydraulic pressure is suppressed, and the increase in the required discharge hydraulic pressure is delayed. Due to the delay in the increase in the required discharge hydraulic pressure, the power of the oil pump 5 is reduced, and the fuel consumption rate of the engine can be improved.

  In addition, the required discharge hydraulic pressure obtained by the above equation (1) has a small time constant and high follow-up performance when the amount of heat generated by combustion in the combustion chamber increases due to an increase in engine load. It will be calculated as a high value. For this reason, the required discharge hydraulic pressure for cooling each device of the second device group (the device whose temperature has increased due to the heat generated by the combustion) is required at an early stage.

  The response delay control when extracting the required discharge hydraulic pressure of the second device group is not limited to that described above. For example, the time constant is corrected in accordance with the heat capacity of each device of the second device group, or after the engine load increases, the time constant is changed (waiting for the state to continue for a predetermined time). May be changed).

  After extracting the required discharge hydraulic pressure of the second device group, the process proceeds to step ST4, and the required discharge hydraulic pressure of the third device group is extracted. Specifically, the pump discharge hydraulic pressure (required hydraulic pressure) required by each device of the third device group is compared, and the highest pump discharge hydraulic pressure is extracted. FIG. 7C shows an example of the change in the required oil pressure of the third device group accompanying the increase in the engine speed. The solid line in the figure is the change in pump discharge hydraulic pressure required for the crankshaft journal 15a (required for cooling and lubrication of the crankshaft journal 15a) among the devices of the third device group, and the broken line in the figure is This is a change in pump discharge hydraulic pressure required for the camshaft journal 13a among the devices of the third device group (required for cooling and lubrication of the camshaft journal 13a).

  Thus, the pump discharge hydraulic pressure required for each device in the third device group depends on the engine speed, and each device in the third device group is an engine speed-dependent hydraulic pressure request device. Can be called. Note that these required oil pressures are obtained as values obtained by correcting the required minimum oil pressure of each device obtained by experiments and simulations by a predetermined amount to increase correction (increasing correction considering the safety factor).

  In the case shown in FIG. 7C, the pump discharge hydraulic pressure required for the crankshaft journal 15a is higher than the pump discharge hydraulic pressure required for the camshaft journal 13a. As the required discharge hydraulic pressure of the group, the pump discharge hydraulic pressure required for the crankshaft journal 15a is extracted.

  If the pump discharge hydraulic pressure required for the camshaft journal 13a is higher than the pump discharge hydraulic pressure required for the crankshaft journal 15a, the required discharge hydraulic pressure for the third device group is the cam The pump discharge hydraulic pressure required for the shaft journal 13a is extracted. Further, when the engine speed increases, the higher pump discharge hydraulic pressure is switched between the pump discharge hydraulic pressure required for the crankshaft journal 15a and the pump discharge hydraulic pressure required for the camshaft journal 13a. The pump discharge hydraulic pressure on the higher side at the current engine speed is extracted.

  Each device in the third device group is a device that uses oil as a coolant and a lubricant. Therefore, until a predetermined time elapses after the engine is started (the device is at a predetermined temperature (a temperature at which cooling is required)). The request is delayed for a period until it is heated to a predetermined time and only when a relative speed of the sliding portion of the device reaches a predetermined speed (speed at which lubrication is required).

  Also, when extracting the required discharge hydraulic pressure of the third device group, the same response delay control as described above is executed. This response delay control is used to temporarily increase the engine speed when the engine speed temporarily increases, that is, when the engine speed decreases again after the engine speed temporarily increases. In view of the fact that the pump discharge hydraulic pressure does not need to be increased accordingly (the temporary increase in engine speed is unlikely to cause a sudden increase in the device temperature or oil shortage at the sliding portion, so there is no need to increase the pump discharge hydraulic pressure). It is what was done. That is, it is a control for increasing the required discharge hydraulic pressure in response to the increase in the engine speed only when the state in which the engine speed has increased continues for a predetermined time. In other words, this response delay control is to calculate the required discharge hydraulic pressure so as to increase the required discharge hydraulic pressure of the third device group when the state where the engine speed is high continues for a predetermined time. In the present invention, “corresponding to changes in the operating state of the internal combustion engine at the calculated hydraulic pressure is set higher as the rotational speed of the internal combustion engine is higher”). Specifically, by appropriately setting the time constant in the equation (1), the responsiveness of the required discharge hydraulic pressure in accordance with the fluctuation of the engine speed is adjusted. Since this equation (1) has been described above, a description thereof is omitted here.

  Note that the previous value of the required discharge hydraulic pressure in the equation (1) when calculating the required discharge hydraulic pressure of the third device group corresponds to the required discharge hydraulic pressure calculated in step ST4 in the previous routine. The required discharge hydraulic pressure map value is a required discharge hydraulic pressure value read from a map stored in advance in the ROM 102 in order to extract the required discharge hydraulic pressure according to the engine speed. This map is created in advance based on experiments and simulations.

  Further, the time constant is changed according to the engine speed, and the higher the engine speed, the smaller the time constant is set, and the amount of change in the required discharge hydraulic pressure obtained by the equation (1). Is greatly gained. For this reason, when the engine speed increases temporarily, the time constant temporarily changes in the direction of decreasing, but as the engine speed subsequently decreases, the time constant increases and the required discharge hydraulic pressure The rise is suppressed (responsiveness to the side where the required discharge hydraulic pressure rises decreases). As a result, unless the state in which the engine speed is high continues, an increase in the required discharge hydraulic pressure is suppressed, and the increase in the required discharge hydraulic pressure is delayed. Due to the delay in the increase in the required discharge hydraulic pressure, the power of the oil pump 5 is reduced, and the fuel consumption rate of the engine can be improved.

  In addition, the required discharge hydraulic pressure obtained by the above formula (1) is the case where the amount of heat generated at the sliding portion of the device increases or the oil runs out due to an increase in the engine speed. Is calculated as a high value with a high follow-up property because the time constant becomes small. For this reason, the required discharge hydraulic pressure for cooling and lubricating each device of the third device group is required at an early stage.

  Note that the response delay control when extracting the required discharge hydraulic pressure of the third device group is not limited to that described above. For example, the time constant is corrected according to the heat capacity and material (material of the crankshaft or the like) of each device in the third device group, or the state is continued for a predetermined time after the engine speed increases. After waiting, the time constant may be changed (changed to a smaller side).

  After the required discharge hydraulic pressure of each device group is extracted as described above, the process proceeds to step ST5, the required discharge hydraulic pressure of each device group is compared, and the highest required discharge hydraulic pressure is extracted among these, The target discharge hydraulic pressure of the pump 5 is set.

  FIG. 8 is a diagram showing the transition of the pump discharge hydraulic pressure required for each device group (shown in FIGS. 7A to 7C) in an overlapping manner. In FIG. 8, the required discharge hydraulic pressure of the first device group is indicated by a broken line, the required discharge hydraulic pressure of the second device group is indicated by a one-dot chain line, and the required discharge hydraulic pressure of the third device group is indicated by a two-dot chain line. The maximum value of the required discharge oil pressure of each device group for each rotation speed or each engine load is connected by a solid line A. The target discharge hydraulic pressure of the oil pump 5 is defined by the solid line A.

  That is, a period in which the required discharge hydraulic pressure of the first device group is higher than the required discharge hydraulic pressures of the other device groups (second and third device groups) in accordance with changes in engine speed or engine load (period in FIG. 8). In T1), the required discharge hydraulic pressure of the first device group is set as the target discharge hydraulic pressure of the oil pump 5. Further, in a period (period T2 in FIG. 8) in which the required discharge hydraulic pressure of the second device group is higher than the required discharge hydraulic pressure of the other device groups (first and third device groups), this second The required discharge hydraulic pressure of the device group is set as the target discharge hydraulic pressure of the oil pump 5. Further, in a period (period T3 in FIG. 8) in which the required discharge hydraulic pressure of the third device group is higher than the required discharge hydraulic pressure of the other device groups (first and second device groups), this third The required discharge hydraulic pressure of the device group is set as the target discharge hydraulic pressure of the oil pump 5.

  Thereafter, the process proceeds to step ST6, and the OCV 60 is controlled so that the target discharge hydraulic pressure of the oil pump 5 is obtained. That is, the position of the spool is continuously changed according to a signal (Duty signal) from the ECU 100, and the pressure of the oil sent from the control port 60a to the control oil passage 61 is linearly increased or decreased to linearly adjust the adjustment ring 53. The target discharge hydraulic pressure is obtained by displacing. As specific control for obtaining the target discharge hydraulic pressure, for example, feedback control based on the hydraulic pressure detected by the hydraulic sensor 118 is performed.

  The above operation is repeated, and the discharge hydraulic pressure is adjusted according to the operating state of the engine.

  As described above, in the present embodiment, for example, at the initial cold start of the engine, the hydraulic pressure required for the first device group is higher than the hydraulic pressure required for the other device groups. (See period T1 in FIG. 8). In this case, the variable capacity mechanism is controlled so that the hydraulic pressure required for the first device group is the target discharge hydraulic pressure of the oil pump 5. In other words, only the hydraulic pressure required for the first device group is taken into consideration, and the oil pump discharge hydraulic pressure (for example, about the hydraulic pressure required to operate the VVT mechanism 13c) is set. Therefore, the oil pump discharge hydraulic pressure is not set higher than necessary, the power of the oil pump 5 can be suppressed to the minimum necessary, and the fuel consumption rate of the engine can be improved.

  A solid line B in FIG. 8 shows an example of the transition of the pump discharge hydraulic pressure in the prior art. As described above, in the prior art, the target discharge hydraulic pressure of the oil pump is set only in accordance with the change in the engine speed or the engine load without considering the required hydraulic pressure for each device. In contrast, the solid line A, which is the transition of the target discharge hydraulic pressure of the oil pump 5 in the present embodiment, is set lower than the target discharge hydraulic pressure in the prior art (solid line B), and the power of the oil pump 5 is reduced. Can be reduced. That is, the target discharge hydraulic pressure is set low by the difference between the solid line B and the solid line A, the power of the oil pump 5 is reduced, and the fuel consumption rate of the engine is improved.

-Other embodiments-
In the embodiment described above, the case where the present invention is applied to the oil pump 5 mounted in the automobile gasoline engine has been described. The present invention is not limited to this, and can be applied to an oil pump mounted on an engine other than an automobile. It can also be applied to an oil pump mounted on a diesel engine.

  In the embodiment, the VVT mechanism 13c and the chain tensioner 12 are used as the devices of the first device group, the turbocharger 16 and the piston 14b are used as the devices of the second device group, and the crankshaft journal 15a is used as the device of the third device group. The camshaft journal 13a is illustrated as an example. The present invention is not limited to this, and various devices can be applied. For example, a variable valve lift mechanism is applied as a device of the first device group, a cylinder head is applied as a device of the second device group, or a connecting rod is applied as a device of the third device group You can also.

  In the above-described embodiment, the case where the present invention is applied to a variable displacement oil pump having a variable displacement mechanism has been described. However, a variable discharge pressure mechanism that operates by receiving power from an engine (internal combustion engine). The present invention can also be applied to an oil pump that includes a concept of a variable capacity mechanism, and has a mechanism that makes the discharge hydraulic pressure variable.

  The present invention can be applied to discharge hydraulic pressure control of a variable displacement oil pump mounted on an automobile engine.

12 Chain tensioner 13a Camshaft journal 13c VVT mechanism 14a Oil jet 14b Piston 15a Crankshaft journal 16 Turbocharger 5 Oil pump (variable capacity oil pump)
100 ECU
111 Air Flow Meter 114 Accelerator Position Sensor 116 Crank Position Sensor

Also, the oil pressure required for the device that uses the oil as hydraulic oil is lower than the oil pressure required for the device that uses oil as cooling oil, and the device that uses the oil as lubricating oil and cooling oil is required. When the oil pressure is lower than the oil pressure, the oil pressure required for the device that uses the oil as cooling oil and the oil pressure that is higher among the oil pressure required for the device that uses the oil as lubricating oil and cooling oil are The variable capacity mechanism is controlled to have a pump discharge hydraulic pressure.

When the amount of heat generated in the combustion chamber of the internal combustion engine reaches a predetermined amount or the rotational speed of the internal combustion engine reaches a predetermined value due to completion of the warm-up operation of the internal combustion engine, the oil is used as cooling oil. The oil pressure required for devices and the oil pressure required for devices that use oil as lubricating oil and cooling oil are high, and the oil pressure required for devices that use oil as hydraulic oil is lower than these oil pressures. . In this case, in the present solution, the hydraulic pressure required for devices that utilize oil as a cooling oil, and a high side pressure of the hydraulic pressure required in devices that utilize oil as a lubricating oil and cooling oil Therefore, the variable capacity mechanism is controlled so as to obtain the oil pump discharge hydraulic pressure. For this reason, it is possible to minimize the power of the oil pump while satisfying the requirements (required hydraulic pressure) of all devices, so that the performance, lubrication and cooling requirements of each device can be met. Ensuring and improving the fuel consumption rate of the internal combustion engine can be combined.

Further, a plurality of devices that use the oil as lubricating oil and cooling oil are defined as a third device group, and the highest hydraulic pressure required for each of the plurality of devices is required for the third device group. The oil pressure is represented by a hydraulic pressure required for a device that uses the oil as hydraulic oil, and a hydraulic pressure required for a device that uses the oil as cooling oil .

Claims (10)

In a control device for a variable displacement oil pump that operates by receiving power from an internal combustion engine and includes a variable displacement mechanism,
Of each device provided in the oil supply system of the internal combustion engine, the oil pressure required for a device that uses oil as hydraulic oil is heated by receiving heat accompanying combustion in the combustion chamber and the oil is cooled. When the oil pressure is higher than the oil pressure required for the device used as the oil, and the friction oil is generated by sliding and higher than the oil pressure required for the device using the oil as the lubricating oil and the cooling oil, the oil is used as the working oil. A control apparatus for a variable displacement oil pump, characterized in that the displacement variable mechanism is controlled so that a hydraulic pressure required for a device to be used is an oil pump discharge hydraulic pressure. In the control apparatus of the variable displacement oil pump according to claim 1,
The oil pressure required for the device that uses the oil as the working oil is lower than the oil pressure required for the device that uses the oil as the cooling oil, and is required for the device that uses the oil as the lubricating oil and the cooling oil. When lower than the oil pressure, the oil pump discharges the oil pressure required for the device that uses the oil as a lubricating oil and the oil pressure required for the device that uses the oil as a lubricating oil and a cooling oil. A control apparatus for a variable displacement oil pump, wherein the displacement variable mechanism is controlled to be hydraulic. The control apparatus for a variable displacement oil pump according to claim 1 or 2,
The oil pressure required for the device that uses the oil as cooling oil is calculated according to the operating state of the internal combustion engine,
The follow-up performance of the calculated hydraulic pressure with respect to the change in the operating state of the internal combustion engine is set so as to increase as the amount of heat generated by combustion in the combustion chamber of the internal combustion engine increases. Control device. The control apparatus for a variable displacement oil pump according to claim 1 or 2,
The oil pressure required for the device that uses the oil as a lubricating oil and a cooling oil is calculated according to the operating state of the internal combustion engine,
A control apparatus for a variable displacement oil pump, wherein the followability of the calculated hydraulic pressure with respect to a change in the operating state of the internal combustion engine is set higher as the rotational speed of the internal combustion engine is higher. In the control apparatus of the variable displacement type oil pump according to any one of claims 1 to 4,
A plurality of devices that use the oil as hydraulic oil is defined as a first device group, and the highest hydraulic pressure required for each of the plurality of devices is the hydraulic pressure required for the first device group. And the hydraulic pressure required for a device that uses the oil as a cooling oil, and the hydraulic pressure required for a device that uses the oil as a lubricating oil and a cooling oil. A variable displacement oil pump control device. In the control apparatus of the variable displacement oil pump according to claim 5,
The control device for a variable displacement oil pump, wherein the plurality of devices that use the oil as hydraulic oil are a variable valve timing mechanism and a chain tensioner. In the control apparatus of the variable displacement type oil pump according to any one of claims 1 to 4,
A plurality of devices that use the oil as cooling oil are defined as a second device group, and the highest hydraulic pressure required for each of the plurality of devices is the hydraulic pressure required for the second device group. And the hydraulic pressure required for a device that uses the oil as hydraulic oil, and the hydraulic pressure required for a device that uses the oil as lubricating oil and cooling oil. A variable displacement oil pump control device. The control apparatus for a variable displacement oil pump according to claim 7,
The control apparatus for a variable displacement oil pump, wherein the plurality of devices that use the oil as cooling oil are a turboshaft of a turbocharger and an oil jet for cooling a piston. In the control apparatus of the variable displacement type oil pump according to any one of claims 1 to 4,
A plurality of devices that use the oil as lubricating oil and cooling oil are defined as a third device group, and the highest hydraulic pressure required for each of the plurality of devices is required for the third device group. The hydraulic pressure is represented by a hydraulic pressure required for a device that uses the oil as hydraulic oil, and the hydraulic pressure required for a device that uses the oil as hydraulic oil. A variable displacement oil pump control device. The control apparatus for a variable displacement oil pump according to claim 9,
A device for using the oil as lubricating oil and cooling oil includes a crankshaft journal and a camshaft journal.

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