JP2010242529A - Hydraulic control apparatus of internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hydraulic control apparatus of internal combustion engine capable of suppressing generation of abnormal sounds due to frequent changes of operation modes of a pressure stage switching mechanism. <P>SOLUTION: A hydraulic control apparatus of internal combustion engine includes a pressure stage switching mechanism for switching pressure stages of oils to be supplied to respective parts of an engine between a high-pressure stage and a low-pressure stage, and controls pressures of oils by switching pressure stages of oils depending on an engine rotational speed NE. Further, when the pressure stage of oil is set to the low-pressure stage, the engine rotational speed NE may be in some cases equal to or higher than a first predetermined rotational speed Nx (KL), and accordingly the pressure stage of oil is changed to the high-pressure stage. On the other hand, when the pressure stage of oil is set to the high-pressure stage, the engine rotational speed NE may be in some cases equal to or lower than a second predetermined rotational speed Ny (KL), which is larger than the first predetermined rotational speed Nx (KL), and accordingly the pressure stage of oil is changed to the low-pressure stage. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a hydraulic control device for an internal combustion engine.

  A conventional internal combustion engine hydraulic control device includes a relief valve that opens when the pressure of oil discharged from an oil pump exceeds a predetermined valve opening pressure, and allows part of the oil to escape to the relief passage through the relief valve. I am doing so. Thereby, the pressure of the oil supplied to each part of the engine is controlled. An example of such a hydraulic control device for an internal combustion engine is disclosed in Patent Document 1.

  Further, a hydraulic control including a pressure stage switching mechanism that switches a pressure stage of oil supplied to each part of the internal combustion engine between a high pressure stage and a low pressure stage by switching the valve opening pressure of the relief valve to, for example, two stages. Devices have been developed. According to such a hydraulic control device, for example, when the engine is in an operating state where it is not necessary to increase the pressure of oil supplied to each part of the engine, the oil pressure stage is changed to the low pressure stage, thereby improving fuel efficiency. be able to.

JP 2007-107485 A

  By the way, in such a hydraulic control device, when the oil pressure stage is a low pressure stage, for example, when the engine rotational speed is equal to or higher than a predetermined rotational speed, the oil pressure stage is changed to the high pressure stage, If the engine rotational speed falls below the predetermined rotational speed when the oil pressure stage is a high pressure stage, the oil pressure stage is changed to a low pressure stage. For this reason, if the engine rotational speed fluctuates in the vicinity of the predetermined rotational speed and the engine rotational speed exceeds or falls below the predetermined rotational speed in a short time, the operation mode of the pressure stage switching mechanism is accordingly accompanied. Will be changed frequently. As a result, abnormal noise and vibration caused by this problem become a problem.

  These problems are not limited to switching the oil pressure stage in accordance with the engine speed, but are generally common in hydraulic control devices for internal combustion engines that switch the oil pressure stage in accordance with the engine state quantity. It has become.

  The present invention has been made in view of such circumstances, and the object thereof is to suppress the generation of abnormal noise and the occurrence of vibration caused by frequent changes in the operation mode of the pressure stage switching mechanism. An object of the present invention is to provide a hydraulic control device for an internal combustion engine.

Hereinafter, means for solving the above-described problems and the effects thereof will be described.
(1) The invention described in claim 1 is provided with a pressure stage switching mechanism that switches a pressure stage of oil supplied to each part of the engine between a high pressure stage and a low pressure stage, and the oil is supplied according to the engine state quantity. In an oil pressure control apparatus for an internal combustion engine that controls oil pressure by switching a pressure stage, the oil state is obtained when an engine state quantity becomes a first predetermined value or more when the oil pressure stage is a low pressure stage. The oil pressure stage is changed to a high pressure stage, and when the oil pressure stage is a high pressure stage, the engine state quantity becomes equal to or less than a second predetermined value smaller than the first predetermined value. The gist is to change the pressure stage to a low pressure stage.

  According to this configuration, the first predetermined value, which is the engine state quantity for changing the oil pressure stage from the low pressure stage to the high pressure stage, is the engine state for changing the oil pressure stage from the high pressure stage to the low pressure stage. It is larger than a second predetermined value that is an amount. As a result, the engine state quantity for changing the oil pressure stage from the low pressure stage to the high pressure stage is the same as the engine state quantity for changing the oil pressure stage from the high pressure stage to the low pressure stage. In comparison with this, it is possible to suppress frequent changes in the operation mode of the pressure stage switching mechanism in accordance with fluctuations in the engine state quantity. Accordingly, it is possible to suppress the occurrence of abnormal noise and vibration due to frequent changes in the operation mode of the pressure stage switching mechanism.

  (2) The invention described in claim 2 is a predetermined value setting means for variably setting at least one of the first predetermined value and the second predetermined value in the hydraulic control apparatus for an internal combustion engine according to claim 1. And the predetermined value setting means sets the predetermined value so that the degree of deviation between the first predetermined value and the second predetermined value is a predetermined degree. When it is estimated that the frequency of fluctuation of the quantity is equal to or higher than the predetermined frequency, these predetermined values are set so that the degree of divergence between the first predetermined value and the second predetermined value is larger than the case where the frequency is not so. The gist is to set.

  According to the above configuration, when it is estimated that the change frequency of the operation mode of the pressure stage switching mechanism is equal to or higher than the predetermined level, the degree of divergence between the first predetermined value and the second predetermined value becomes relatively large. Since these predetermined values are set as described above, it is possible to further suppress frequent changes in the operation mode of the pressure stage switching mechanism in accordance with fluctuations in the engine state quantity.

  On the other hand, if the first predetermined value is set to be unnecessarily large, the oil pressure stage cannot be set to the high pressure stage even if the engine operating state where the oil pressure should be increased is high, and the oil pressure is required. As a result of an increase in the period lower than the applied pressure, the reliability of the internal combustion engine may be reduced. Further, if the second predetermined value is set to be unnecessarily small, the oil pressure stage does not become a low pressure stage even when the engine operation state is not required to increase the oil pressure, and the oil pressure is unnecessarily high. As a result of the increase in the period, there is a risk that the fuel consumption will deteriorate. For this reason, the frequency of the fluctuation of the engine state quantity including the first predetermined value and the second predetermined value is low, and the occurrence of abnormal noise and vibration due to the change of the operation mode of the pressure stage switching mechanism is not a problem. Until then, if the degree of deviation between the first predetermined value and the second predetermined value is set large, problems such as a decrease in the reliability of the internal combustion engine and a deterioration in fuel consumption will be in vain.

  In this regard, according to the above configuration, when it is not estimated that the frequency of change of the operation mode of the pressure stage switching mechanism is equal to or higher than the predetermined level, the degree of divergence between the first predetermined value and the second predetermined value is relatively low. Since these predetermined values are set so as to be reduced, it is possible to prevent unnecessary problems such as a decrease in the reliability of the internal combustion engine and a deterioration in fuel consumption due to the fact that the above degree of deviation is set large. Can do. Therefore, the first predetermined value and the second predetermined value can be appropriately set according to the frequency of change of the operation mode of the pressure stage switching mechanism.

  (3) According to a third aspect of the invention, as in the second aspect of the invention, the predetermined value setting means estimates the frequency of fluctuation of the engine state quantity based on the engine operating state. Can be embodied.

  (4) According to a second or third aspect of the invention, as in the fourth aspect of the invention, the internal combustion engine is mounted on a vehicle, and the predetermined value setting means is in a vehicle running state. The embodiment can be embodied in such a manner that the frequency of fluctuation of the engine state quantity is estimated based on the above.

  (5) According to a fifth aspect of the present invention, as in the invention according to any one of the second to fourth aspects, the predetermined value setting means variably sets only the second predetermined value. Thus, the embodiment can be embodied in such a manner that the degree of deviation between the first predetermined value and the second predetermined value is changed. In this case, since the first predetermined value is not increased when the degree of deviation between the first predetermined value and the second predetermined value is increased, the engine operating state in which the oil pressure should be increased Even if it becomes, the problem that the pressure stage of oil cannot be made into a high pressure stage does not arise. As a result, it is possible to avoid instability of the engine operation when suppressing the generation of abnormal noise and vibration due to frequent changes in the operation mode of the pressure stage switching mechanism.

  (6) The invention according to claim 6 is provided with a pressure stage switching mechanism for switching a pressure stage of oil supplied to each part of the engine between a high pressure stage and a low pressure stage, and the oil is supplied according to the engine state quantity. In a hydraulic control device for an internal combustion engine that controls oil pressure by switching pressure stages, the oil pressure stage is determined when an engine state quantity exceeds a predetermined value when the oil pressure stage is a low pressure stage. Is changed to the high pressure stage, and the oil pressure stage is changed to the low pressure stage when the state where the engine state quantity is below the predetermined value continues for a predetermined period when the oil pressure stage is the high pressure stage. The gist is to do.

  According to this configuration, when the oil pressure stage is set to the high pressure stage, the engine state is immediately changed to the low pressure stage when the engine state quantity falls below a predetermined value. It is possible to prevent the operation mode of the pressure stage switching mechanism from being frequently changed as the amount varies. Accordingly, it is possible to suppress the occurrence of abnormal noise and vibration due to frequent changes in the operation mode of the pressure stage switching mechanism.

  By the way, when the oil pressure stage is changed from the low pressure stage to the high pressure stage, the oil pressure stage is changed to the low pressure stage when the state in which the engine state quantity exceeds the predetermined value continues for a predetermined period. Thus, it is possible to further suppress frequent changes in the operation mode of the pressure stage switching mechanism in accordance with fluctuations in the engine state quantity. However, in this case, even if the engine operating state in which the oil pressure should be increased is reached, the oil pressure stage cannot be changed to the high pressure stage, resulting in an increase in the period during which the oil pressure is lower than the required pressure. The reliability of the internal combustion engine may be reduced. In this regard, according to the above configuration, when the oil pressure stage is a low pressure stage, the oil pressure stage is immediately changed to the high pressure stage when the engine state quantity is equal to or greater than the predetermined value. There is no problem that the oil pressure stage cannot be set to the high pressure stage even when the engine operating state in which the oil pressure should be increased is reached.

  (7) The invention according to claim 7 is the hydraulic control apparatus for an internal combustion engine according to claim 6, further comprising predetermined period setting means for variably setting the predetermined period, wherein the predetermined period setting means is the predetermined value. The gist of the present invention is that the predetermined period is set longer than that in the case where it is estimated that the frequency of the fluctuation of the engine state quantity including the frequency is equal to or higher than the predetermined frequency.

  According to the above configuration, when it is estimated that the frequency of change of the operation mode of the pressure stage switching mechanism is equal to or higher than the predetermined degree, the predetermined period is set to be relatively long, so that the pressure accompanying the fluctuation of the engine state quantity It is possible to further suppress frequent changes in the operation mode of the stage switching mechanism.

  On the other hand, if the predetermined period is set unnecessarily long, the oil pressure stage does not become a low pressure stage even if the engine pressure does not need to be increased, and there is a period during which the oil pressure is unnecessarily high. As a result of the increase, the fuel consumption may deteriorate. For this reason, the predetermined period is set to be long until the frequency of fluctuation of the engine state quantity including the predetermined value is low and the occurrence of abnormal noise or vibration due to the change in the operation mode of the pressure stage switching mechanism is not a problem. If this is done, the fuel efficiency will be deteriorated.

  In this regard, according to the above configuration, when it is not estimated that the frequency of change of the operation mode of the pressure stage switching mechanism exceeds a predetermined degree, the predetermined period is set to be relatively short, and thus the predetermined period is unnecessary. It is possible to suppress wasteful deterioration of fuel consumption due to being set to be long. Accordingly, the predetermined period can be appropriately set according to the frequency of change of the operation mode of the pressure stage switching mechanism.

  (8) According to the invention described in claim 7, according to the invention described in claim 8, the predetermined period setting means estimates the frequency of fluctuation of the engine state quantity based on the engine operating state. Can be embodied.

  (9) According to the seventh or eighth aspect of the invention, as in the ninth aspect of the invention, the internal combustion engine is mounted on a vehicle, and the predetermined period setting means is in a vehicle running state. The embodiment can be embodied in such a manner that the frequency of fluctuation of the engine state quantity is estimated based on the above.

  (10) The invention according to any one of claims 1 to 9 can be embodied with an aspect in which an engine rotational speed is included as the engine state quantity, as in the invention according to claim 10. it can.

  (11) Further, in the case of a gasoline engine, in addition to the engine rotational speed, the engine load can be embodied in such a manner that the engine load is included as an engine state quantity.

  (12) Further, in the case of a diesel engine, in addition to the engine rotational speed, according to the invention described in claim 12, it can be embodied in such a manner that the fuel injection amount is included as the engine state amount.

BRIEF DESCRIPTION OF THE DRAWINGS Schematic which shows the schematic structure about the hydraulic control apparatus of the internal combustion engine which concerns on one Embodiment of this invention. It is sectional drawing for demonstrating the operation | movement aspect of the relief valve in the embodiment, Comprising: (a) Sectional drawing of a relief valve when a switching valve is made into a valve opening state, (b) Switching valve is a valve closing state Sectional drawing of a relief valve when it is said. The graph which shows the relationship between the engine speed in the predetermined | prescribed engine load of the same embodiment, and the oil pressure after adjusting with a relief valve. The flowchart which shows the process sequence of the electricity supply control of the switching valve in the embodiment. The flowchart which showed the process sequence which sets the 2nd predetermined rotation speed in the embodiment. A map in which a low pressure stage region in which the switching valve is opened and a high pressure stage region in which the switching valve is closed is defined by the engine speed and the engine load, and the shift stage of the automatic transmission is a low speed stage. The map to be applied if A map in which a low pressure stage region in which the switching valve is opened and a high pressure stage region in which the switching valve is closed is defined by the engine speed and the engine load, and the shift stage of the automatic transmission is the high speed stage. The map to be applied if

  Hereinafter, an embodiment in which a hydraulic control device for an internal combustion engine according to the present invention is embodied as a hydraulic control device for an in-vehicle gasoline engine (hereinafter, “internal combustion engine”) will be described with reference to FIGS.

FIG. 1 shows a schematic configuration of a hydraulic control device for an internal combustion engine according to the present embodiment.
As shown in the figure, the internal combustion engine is provided with a main supply passage 11 for supplying oil stored in the oil pan 12 to each part of the internal combustion engine. An engine-driven oil pump 14 that sucks and discharges oil is provided in the middle of the main supply passage 11. An oil strainer 13 is provided at the upstream end of the main supply passage 11 (the end on the oil pan 12 side) for filtering relatively large impurities contained in the oil. In addition, an oil filter 15 for filtering relatively small impurities contained in the oil is provided on the downstream side of the oil pump 14 in the main supply passage 11. When the oil pump 14 is driven by the engine output, the oil in the oil pan 12 is sucked by the pump 14 through the main supply passage 11 and discharged to the downstream side of the passage 11. And various parts of the internal combustion engine, for example, various hydraulically driven devices driven by oil pressure, a piston jet mechanism for cooling the piston by injecting oil to the engine piston for taking out engine output, and It is supplied to a lubricated part or the like (both not shown) of the internal combustion engine.

  The main supply passage 11 is provided with a relief passage 16 that connects the downstream side and the upstream side of the oil pump 14. The relief passage 16 has one end connected to the downstream side of the oil filter 15 in the main supply passage 11 and the other end connected to the upstream side of the oil pump 14 and downstream of the oil strainer 13 in the main supply passage 11. Has been. The relief passage 16 is provided with a relief valve 21 that opens when the pressure of the oil acting on the relief passage 16 becomes equal to or higher than a predetermined valve opening pressure Prrf and releases a part of the oil to the upstream side of the oil pump 14.

  The relief valve 21 is housed in a cylindrical housing 22 having a bottom on one side provided in the relief passage 16 and a housing chamber 23 that is an internal space of the housing 22. A cylindrical valve body 25 is provided so as to be displaceable in the direction A "). In addition, a variable member 24 having a single-sided bottomed cylindrical shape is provided in the housing chamber 23 so as to be displaceable along the axial direction A. The housing 22 and the variable member 24 are provided such that their bottom portions 22A and 24A are positioned on the upstream side (upper side in the drawing) in the relief passage 16, respectively. The relief valve 21 is provided between the fixed member 26 that covers the opening of the end 22B opposite to the bottom 22A of the housing 22 (the lower side in the figure), and between the valve body 25 and the fixed member 26. A spring 27 is provided to bias the valve body 25 toward the bottom 24A side (the upper side in the drawing) of the variable member 24. The outer diameter of the variable member 24 is slightly smaller than the inner diameter of the housing 22. The outer diameter of the valve body 25 is slightly smaller than the inner diameter of the variable member 24. The fixing member 26 includes a cylindrical diameter-enlarged portion 26A and a columnar diameter-reduced portion 26B that is provided integrally and coaxially with the diameter-enlarged portion 26A and is reduced in diameter as compared with the diameter-enlarged portion 26A. is doing. The enlarged diameter portion 26A is in contact with the lower end surface of the end portion 22B of the housing 22, and the reduced diameter portion 26B has an end portion on the side opposite to the bottom portion 24A of the variable member 24 (lower side in the figure). It is in contact with the inner peripheral surface of 24B.

  An inlet side through hole 22C and an inlet side communication hole 24C having the same diameter as the inlet side through hole 22C are formed at the centers of the bottom 22A of the housing 22 and the bottom 24A of the variable member 24, respectively. The through hole 22 </ b> C and the communication hole 24 </ b> C form a part of the relief passage 16.

  An outlet side through hole 22D that penetrates the same side portion and extends in the axial direction A is formed at a central position in the axial direction A (left central position in the figure) in the side portion of the housing 22 and corresponds to this. An outlet side communication hole 24D that penetrates the same side part and has a shorter length in the axial direction A than the outlet side through hole 22D is formed in the side part of the variable member 24. In a state where the variable member 24 is located closest to the bottom 22A side of the housing 22 in the axial direction A (hereinafter, this position is referred to as “first position”), the bottom 24A side (upper side in the drawing) of the outlet side communication hole 24D. ) And the portion on the bottom 22A side (upper side in the drawing) of the outlet side through hole 22D coincide with each other. Further, in a state where the variable member 24 is located closest to the fixing member 26 in the axial direction A (hereinafter, this position is referred to as “second position”), the outlet side communication hole 24D has a fixing member 26 side (in the drawing). The part on the lower side and the part on the fixing member 26 side (lower side in the figure) of the outlet side through hole 22D coincide. Thus, the opening position of the outlet portion 23D of the storage chamber 23 is changed in the axial direction A by changing the position of the outlet side communication hole 24D of the variable member 24 in the axial direction.

  The length of the variable member 24 in the axial direction A is shorter than that of the storage chamber 23. As a result, the lower surface of the end portion 24B of the variable member 24, the inner peripheral surface of the end portion 22B of the housing 22, the upper surface of the reduced diameter portion 26B, and the outer peripheral surface of the enlarged diameter portion 26A of the fixing member 26 are formed into a predetermined ring shape. A space 23F is formed. In addition, an introduction through-hole 22 </ b> E that connects the space 23 </ b> F and the outside of the housing 22 is formed at an end 22 </ b> B (right side in the drawing) of the housing 22. The introduction through hole 22 </ b> E and the upstream side of the relief valve 21 in the relief passage 16 are connected by an introduction passage 28. In the middle of the introduction passage 28, an electromagnetic solenoid type switching valve 29 for switching whether or not the oil upstream of the relief valve 21 in the relief passage 16 is introduced into the predetermined space 23F through the introduction through hole 22E. Is provided. Here, in this embodiment, when energization is performed on the solenoid of the switching valve 29, the valve 29 is opened, and when energization of the solenoid of the switching valve 29 is stopped, the valve 29 is closed. It is configured.

  Output signals from various sensors for grasping the engine operating state are input to the electronic control unit 30 that performs energization control of the switching valve 29. Examples of the various sensors include an engine rotation speed sensor 41 that detects the engine rotation speed NE, an intake air amount sensor 42 that detects the intake air amount GA, and a cooling water temperature sensor 43 that detects the temperature THW of the engine cooling water. . The electronic control device 30 receives output signals from various sensors for grasping the running state of the vehicle. Examples of the various sensors include an acceleration sensor 44 that detects the acceleration G of the vehicle, a vehicle speed sensor 45 that detects the vehicle speed V, and the like. The electronic control unit 30 is also input with information on the shift stage of the automatic transmission. The electronic control unit 30 grasps the engine operating state and the traveling state of the vehicle based on output signals from various sensors, and executes energization control of the switching valve 29 according to this. Then, by switching the valve opening pressure Prrf of the relief valve 21 as described below, the pressure stage of oil supplied to each part of the internal combustion engine is switched between the high pressure stage and the low pressure stage. In the present embodiment, the pressure passage switching mechanism 20 is configured by the relief passage 16, the relief valve 21, the introduction passage 28, and the switching valve 29.

Next, the operation mode of the relief valve 21 and the operation mode of the control mode will be described with reference to FIGS.
FIG. 2A shows a cross-sectional structure of the relief valve 21 when the switching valve 29 is opened. FIG. 2B shows a cross-sectional structure of the relief valve 21 when the switching valve 29 is closed.

  First, when the switching valve 29 is opened, a part of the oil discharged from the oil pump 14 passes through the introduction passage 28 and the introduction portion 23E of the storage chamber 23 as shown in FIG. It is introduced into the space 23F. As a result, the variable member 24 is pushed up in the valve closing direction (upward in the drawing) of the valve body 25 by the hydraulic pressure, so that the variable member 24 is held at the “first position”. In such a state, as the engine rotational speed NE increases, the pressure of oil discharged from the oil pump 14 increases, and the pressure of oil acting in the valve opening direction (downward in the figure) on the valve body 25 increases. Then, when the valve body 25 is displaced to the position shown in the figure or to a position below the first predetermined pressure Prrf1, the inlet portion 23C and the outlet portion 23D of the storage chamber 23 are in communication with each other. . As a result, excess oil on the downstream side of the oil pump 14 is released to the upstream side of the oil pump 14 through the relief passage 16, so that the oil pressure stage is changed to a low pressure stage.

  Next, when the switching valve 29 is closed, oil is not introduced into the predetermined space 23F through the introduction passage 28 as shown in FIG. As a result, the hydraulic pressure applied to the variable member 24 through the introduction passage 28 is a force based on the pressure of the oil flowing from the inlet 23C of the storage chamber 23, that is, the valve body 25 is opened against the member 24. The force is smaller than the force acting in the direction (downward in the figure), and the variable member 24 is displaced to the “second position”. In such a state, as the engine rotational speed NE increases, the pressure of oil discharged from the oil pump 14 increases, and the pressure of oil acting in the valve opening direction (downward in the figure) on the valve body 25 increases. Then, when the valve body 25 is displaced to the position shown in the figure or to a position below the second predetermined pressure Prrf2 that is greater than the first predetermined pressure Prrf1, the inlet 23C of the storage chamber 23 The outlet portion 23D is in a communication state. Accordingly, excess oil on the downstream side of the oil pump 14 is released to the upstream side of the oil pump 14 through the relief passage 16, so that the oil pressure stage is changed to a high pressure stage.

  FIG. 3 is a graph showing the relationship between the engine rotational speed NE at a predetermined engine load KL and the oil pressure Ps after pressure regulation by the relief valve 21. In the present embodiment, as the engine load KL, a ratio “GA / of the intake air amount GA at that time and the maximum intake air amount GAmax that is the maximum value of the intake air amount obtained at the engine rotational speed NE at that time. GAmax "is used.

  As shown in FIG. 3, when the switching valve 29 is in the open state, the engine speed NE increases to N0, and when the oil pressure Ps reaches the low-stage valve opening pressure P0, On the other hand, the pressure of the oil acting in the valve opening direction rises to the first predetermined pressure Prrf1, whereby the relief valve 21 is opened, and a part of the oil discharged from the oil pump 14 is oil pump 14. Will escape to the upstream side. Thereby, in the region where the engine rotational speed NE is equal to or higher than N0, the degree of increase in the oil pressure Ps with respect to the increase in the engine rotational speed NE is smaller than in the region where the engine rotational speed NE is less than N0. The pressure stage of the oil supplied to is a low pressure stage.

  If the switching valve 29 is closed at the timing when the engine speed NE further increases to NE1 and the oil pressure Ps becomes P1, the valve opening pressure Prrf of the relief valve 21 is set to the second predetermined pressure. Changed to Prrf2. Thus, until the oil pressure Ps becomes P2 larger than P1, a part of the oil discharged from the oil pump 14 is not released to the upstream side of the oil pump 14, and therefore the oil pressure Ps increases rapidly. It will be. Then, when the oil pressure Ps reaches P2, the relief valve 21 is opened, so that the degree of increase in the oil pressure Ps with respect to the increase in the engine speed NE becomes smaller than before, so that the oil pressure Ps is supplied to each part of the internal combustion engine. The oil pressure stage is the high pressure stage.

  By the way, as described above, in such a hydraulic control device, when the oil pressure stage is a low pressure stage, for example, when the engine rotational speed NE becomes equal to or higher than the predetermined rotational speed N1, the switching valve 29 is supplied. While energization is stopped (the oil pressure stage is changed to the high pressure stage), when the oil pressure stage is set to the high pressure stage, when the engine rotational speed NE falls below the predetermined rotational speed N1, the switching valve 29 is turned on. If energization is performed (the oil pressure stage is changed to the low pressure stage), the following problems may occur. That is, when the engine rotational speed NE fluctuates in the vicinity of the predetermined rotational speed N1 and the engine rotational speed NE is repeatedly increased or decreased below the predetermined rotational speed N1, the switching valve 29 is moved accordingly. It is frequently opened and closed. As a result, abnormal noise and vibration are generated due to this.

  Therefore, in the present embodiment, the generation of abnormal noise and the occurrence of vibration due to frequent changes in the operation mode of the pressure stage switching mechanism 20 are suppressed as follows. That is, the oil pressure stage is changed to the high pressure stage when the engine speed NE is equal to or higher than the first predetermined speed Nx (KL) when the oil pressure stage is a low pressure stage, while the oil pressure stage is changed. When the stage is set to the high pressure stage, the engine pressure speed NE becomes equal to or lower than the second predetermined rotation speed Ny (KL), which is smaller than the first predetermined rotation speed Nx (KL). Change to Here, in the present embodiment, the first predetermined rotational speed Nx (KL) and the second predetermined rotational speed Ny (KL) are set based on the engine load KL. Specifically, the first predetermined rotational speed Nx (KL) and the second predetermined rotational speed Ny (KL) are set to decrease as the engine load KL increases.

According to such a configuration, it is possible to suppress frequent changes in the operation mode of the pressure stage switching mechanism 20 in accordance with fluctuations in the engine rotational speed NE.
However, if the first predetermined rotational speed Nx (KL) is set to be unnecessarily large, the oil pressure stage cannot be changed to the high pressure stage even if the engine operating state in which the oil pressure should be increased is reached. As a result of an increase in the period during which the pressure is lower than the required pressure, the reliability of the internal combustion engine may be reduced. Also, if the second predetermined rotational speed Ny (KL) is set to be unnecessarily small, the oil pressure stage does not become the low pressure stage even when the engine operation state in which the oil pressure does not need to be increased is reached. As a result of an increase in the period during which the pressure is unnecessarily high, the fuel consumption may deteriorate. For this reason, the frequency of fluctuations in the engine rotational speed NE including the first predetermined rotational speed Nx (KL) and the second predetermined rotational speed Ny (KL) is low, resulting from a change in the operation mode of the pressure stage switching mechanism 20. If the deviation between the first predetermined rotational speed Nx (KL) and the second predetermined rotational speed Ny (KL) is set large until the occurrence of abnormal noise or vibration does not matter, the internal combustion engine Problems such as a decrease in reliability and a decrease in fuel consumption will be in vain.

  Therefore, in the present embodiment, only the second predetermined rotational speed Ny (KL) is appropriately variably set according to the frequency of change of the operation mode of the pressure stage switching mechanism 20 as follows. That is, the deviation between the first predetermined rotational speed Nx (KL) and the second predetermined rotational speed Ny (KL) at the same engine load KL is passed through the electronic control unit 30 (= ΔNx (KL) −ΔNy (KL)). When these predetermined rotational speeds Nx (KL) and Ny (KL) are set so that becomes a predetermined value, the frequency of fluctuations in the engine rotational speed NE including these predetermined rotational speeds Nx (KL) and Ny (KL) is set. presume. Here, the predetermined value is the minimum value of the deviation, but it may be set to a value larger than the minimum value. Then, when it is estimated that the frequency of fluctuation of the engine rotational speed NE is equal to or higher than a predetermined frequency, the first predetermined rotational speed Nx (KL) and the second predetermined rotational speed Ny are compared to the case where the frequency is not so. These predetermined rotational speeds Nx (KL) and Ny (KL) are set so that the deviation from (KL) becomes large. Here, in the present embodiment, the first predetermined rotational speed Nx (KL) and the second predetermined speed when the shift stage of the automatic transmission is set to the low speed stage, compared to the case where the shift stage is set to the high speed stage. Focusing on the fact that the frequency of fluctuation of the engine speed NE including the predetermined speed Ny (KL) is high, the frequency of fluctuation of the engine speed NE is estimated based on the shift stage of the automatic transmission. . The predetermined frequency is variably set according to the engine load KL, and is set in advance through experiments and simulations. The method for estimating the frequency of fluctuation of the engine speed NE including the first predetermined rotational speed Nx (KL) and the second predetermined rotational speed Ny (KL) is not limited to this, and the coolant temperature THW, etc. This may be estimated based on the vehicle running state such as the engine operating state, the vehicle acceleration G, and the vehicle speed V.

  Next, with reference to the flowchart of FIG. 4, the process procedure of the energization control of the switching valve 29 will be described in detail. The series of processes shown in this flowchart is repeatedly executed at predetermined intervals by the electronic control unit 30 during engine operation.

  In this process, first, as the process of step S101, the engine speed NE and the engine load KL at that time are read. Next, it is determined whether or not energization to the switching valve 29 is being executed (step S102). That is, it is determined whether or not the pressure stage at that time is a low pressure stage. Here, when energization to the switching valve 29 is being executed (low pressure stage) (step S102: “YES”), the engine rotational speed NE at that time is the first predetermined rotation. It is determined whether or not the speed is Nx (KL) or higher (step S103). As a result, when the engine rotational speed NE is equal to or higher than the first predetermined rotational speed Nx (KL) (step S103: “YES”), the energization to the switching valve 29 is stopped to switch the pressure stage to the high pressure stage. (Step S104), and this series of processes is temporarily terminated. In step S103, when the engine speed NE is not equal to or higher than the first predetermined speed Nx (KL) (step S103: “NO”), step S104 is skipped, that is, the pressure stage is changed to the low pressure stage. In order to maintain the switching valve 29, the series of processes is temporarily terminated while the energization of the switching valve 29 is maintained.

  On the other hand, in step S102, when the switching valve 29 is not energized (high pressure stage) (step S102: “NO”), the engine speed NE at that time is the first. It is determined whether or not it is equal to or less than a predetermined rotational speed Ny (KL) of 2 (step S105). As a result, when the engine rotational speed NE is equal to or lower than the second predetermined rotational speed Ny (KL) (step S105: “YES”), the switching valve 29 is switched to switch the pressure stage from the high pressure stage to the low pressure stage. Energization is executed (step S106), and this series of processes is temporarily terminated. In step S105, if the engine speed NE is not less than or equal to the second predetermined speed Ny (KL) (step S105: “NO”), step S106 is skipped, that is, the pressure stage is changed to the high pressure stage. In order to maintain the switching valve 29, the series of processing is temporarily terminated while the energization to the switching valve 29 is stopped.

  Next, a processing procedure for variably setting the second predetermined rotational speed Ny (KL) will be described in detail with reference to FIGS. FIG. 5 is a flowchart showing a processing procedure for setting the second predetermined rotational speed Ny (KL). A series of processing shown in this flowchart is performed by the electronic control unit 30 every predetermined period during engine operation. It is executed repeatedly. 6 and 7 are maps in which the low pressure stage region in which the switching valve 29 is opened and the high pressure stage region in which the switching valve 29 is closed are defined by the engine speed NE and the engine load KL. FIG. 6 is a map applied when the shift stage of the automatic transmission is at a low speed, and FIG. 7 is applied when the shift stage of the automatic transmission is at a high speed. Map.

  As shown in FIG. 5, in this process, first, as a process in step S201, it is determined whether or not the shift stage of the automatic transmission is set to a low speed stage (step S201). In step S201, when the speed is low (step S201: “YES”), referring to the map shown in FIG. 6, Ny1 (KL) is set to the second predetermined rotational speed Ny (KL). The setting is made (step S202), and this series of processes is temporarily terminated.

  On the other hand, in the determination process of step S201, when the speed is not the low speed (step S201: “NO”), that is, when the speed is the high speed, the second reference is made to the map shown in FIG. Ny2 (KL) is set to the predetermined rotational speed Ny (KL) (step S203), and this series of processes is temporarily terminated.

  Here, as shown in FIGS. 6 and 7, when the first predetermined rotational speed Nx (KL) at the same engine load KL1 is considered, the shift stage of the automatic transmission is set to the low speed stage, Nx1 which is the same value in the case of the high speed stage.

  On the other hand, regarding the second predetermined rotational speed Ny (KL) at the same engine load KL1, Ny11, which is a value when the shift stage of the automatic transmission is set to the low speed stage, is set to the high speed stage. It is made smaller than Ny21 which is the value in the case of That is, when the deviation (= Nx (KL) −Ny (KL)) between the first predetermined rotational speed Nx1 (KL) and the second predetermined rotational speed Ny (KL) at the same engine load KL1 is considered, automatic transmission is performed. The deviation (Nx1-Ny11) when the gear stage of the machine is at a low speed is made larger than the deviation (Nx1-Ny21) when the gear is at a high speed.

According to the hydraulic control apparatus for an internal combustion engine according to the present embodiment described above, the following operational effects can be obtained.
(1) The hydraulic control device for an internal combustion engine includes a pressure stage switching mechanism 20 that switches a pressure stage of oil supplied to each part of the internal combustion engine between a high pressure stage and a low pressure stage. The oil pressure is controlled by switching the oil pressure stage according to the speed NE. Further, when the oil pressure stage is set to the low pressure stage, the oil pressure stage is changed to the high pressure stage when the engine speed NE becomes equal to or higher than the first predetermined rotation speed Nx (KL) through the electronic control unit 30. On the other hand, when the oil pressure stage is the high pressure stage, the engine speed NE is smaller than the first predetermined speed Nx (KL) at the same engine load KL, and the second predetermined speed Ny (KL). ) The oil pressure stage was changed to the low pressure stage when

  At the same engine load KL, the first predetermined rotational speed Nx (KL), which is the engine rotational speed for changing the oil pressure stage from the low pressure stage to the high pressure stage, is changed from the high pressure stage to the low pressure stage. It is larger than the second predetermined rotational speed Ny (KL), which is the engine rotational speed for changing. As a result, at the same engine load KL, the engine rotation speed for changing the oil pressure stage from the low pressure stage to the high pressure stage and the engine rotation speed for changing the oil pressure stage from the high pressure stage to the low pressure stage are obtained. Compared to the case where the values are the same, it is possible to suppress frequent changes in the operation mode of the pressure stage switching mechanism 20 in accordance with fluctuations in the engine rotation speed. Accordingly, it is possible to suppress the generation of abnormal noise and vibration caused by frequent changes in the operation mode of the pressure stage switching mechanism 20.

  (2) Deviation between the first predetermined rotational speed Nx (KL) and the second predetermined rotational speed Ny (KL) at the same engine load KL through the electronic control unit 30 (= ΔNx (KL) −ΔNy (KL)) ) When the predetermined rotational speeds Nx (KL) and Ny (KL) are set such that the predetermined rotational speeds Nx (KL) and Ny (KL) are set, the frequency of fluctuations in the engine rotational speed NE including the predetermined rotational speeds Nx (KL) and Ny (KL). Was decided to be estimated. Further, when it is estimated that the frequency of fluctuation of the engine rotational speed NE is equal to or higher than a predetermined frequency, the first predetermined rotational speed Nx (KL) and the second predetermined rotational speed Ny ( These predetermined rotational speeds Nx (KL) and Ny (KL) are set so that the deviation from KL) becomes large. As a result, the first predetermined rotational speed Nx (KL) and the second predetermined rotational speed Ny (KL) can be appropriately set according to the frequency of change of the operation mode of the pressure stage switching mechanism 20. .

  (3) The electronic control unit 30 variably sets only the second predetermined rotational speed Ny (KL), so that the first predetermined rotational speed Nx (KL) and the second predetermined rotational speed at the same engine load KL are set. The deviation from Ny (KL) (= ΔNx (KL) −ΔNy (KL)) was changed. Thus, when the deviation between the first predetermined rotational speed Nx (KL) and the second predetermined rotational speed Ny (KL) at the same engine load KL is increased, the first predetermined rotational speed Nx (KL) is increased. Since the oil pressure is not increased, there is no problem that the oil pressure stage cannot be set to the high pressure stage even when the engine operation state in which the oil pressure should be increased is reached. Therefore, it is possible to avoid instability of the engine operation when suppressing the generation of abnormal noise and vibration due to frequent changes in the operation mode of the pressure stage switching mechanism 20.

  The hydraulic control device for an internal combustion engine according to the present invention is not limited to the configuration exemplified in the above embodiment, and can be implemented as, for example, the following form appropriately modified.

  In the above embodiment, the gasoline engine is exemplified as the internal combustion engine to which the hydraulic control device is applied. However, the internal combustion engine according to the present invention is not limited to this, and the present invention can also be applied to a diesel engine. In this case, instead of the engine load KL, the first predetermined rotational speed Nx (Q) and the second predetermined rotational speed Ny (Q) may be set based on the fuel injection amount Q.

  In the above embodiment, the oil temperature is not particularly considered, but for example, when the oil temperature is low, such as when it is cold, the oil viscosity is higher and the oil pressure Ps is larger than when the oil temperature is high. Become. Therefore, a plurality of maps shown in FIG. 6 and FIG. 7 may be provided corresponding to a plurality of oil temperature regions, and a corresponding map may be selected according to the oil temperature at that time.

  As in the above embodiment, when the degree of deviation between the first predetermined rotational speed Nx (KL) and the second predetermined rotational speed Ny (KL) is increased, only the second predetermined rotational speed Ny (KL) Is set to be variably set, the engine operation becomes unstable when suppressing the generation of abnormal noise or vibration caused by frequent changes in the operation mode of the pressure stage switching mechanism 20. It is desirable to avoid this. However, within a range where deterioration of the reliability of the internal combustion engine does not become a problem, the first predetermined rotational speed Nx (KL) may be variably set. In this case, the second predetermined rotational speed Ny (KL) may not be variably set.

  As in the above embodiment, when it is estimated that the fluctuation frequency of the engine rotational speed NE is equal to or higher than the predetermined frequency, the first predetermined rotational speed Nx (KL) and the second Setting these predetermined rotational speeds Nx (KL) and Ny (KL) so that the deviation from the predetermined rotational speed Ny (KL) becomes large can be achieved by setting the predetermined rotational speeds Nx (KL) and Ny (KL) to pressure stages. It is desirable to set appropriately according to the frequency of change of the operation mode of the switching mechanism 20. However, the hydraulic control apparatus according to the present invention is not limited to this, and the predetermined rotational speed Nx (KL) and the second predetermined rotational speed Ny (KL) can be fixed values.

  In the above embodiment, the pressure stage is changed based on a comparison between the engine rotational speed NE at that time and the first predetermined rotational speed Nx (KL) or the second predetermined rotational speed Ny (KL). However, the engine state quantity according to the present invention is not limited to the engine speed NE, and may be another engine state quantity such as the engine load KL or the fuel injection quantity Q.

  In the above embodiment, the first predetermined value which is the engine state quantity for switching the oil pressure stage from the low pressure stage to the high pressure stage is the engine state quantity for switching the oil pressure stage from the low pressure stage to the high pressure stage. By setting it to be larger than a certain second predetermined value, it is possible to suppress frequent changes in the operation mode of the pressure stage switching mechanism 20. However, the hydraulic control device for the internal combustion engine according to the present invention is not limited to this. In addition, for example, when the oil pressure stage is set to the low pressure stage, the oil pressure stage is changed to the high pressure stage when the engine state quantity becomes a predetermined value or more, while the oil pressure stage is changed to the high pressure stage. The oil pressure stage may be changed to the low pressure stage when the state in which the engine state quantity is below the predetermined value continues for a predetermined period of time. According to such a configuration, when the oil pressure stage is set to the high pressure stage, the engine state is immediately changed to the low pressure stage when the engine state quantity falls below a predetermined value. It is possible to prevent the operation mode of the pressure stage switching mechanism from being frequently changed as the amount varies.

  By the way, when the oil pressure stage is changed from the low pressure stage to the high pressure stage, the oil pressure stage is changed to the low pressure stage when the state in which the engine state quantity exceeds the predetermined value continues for a predetermined period. Further, it is possible to further suppress the frequent change of the operation mode of the pressure stage switching mechanism 20 in accordance with the fluctuation of the engine state quantity. However, in this case, even if the engine operating state in which the oil pressure should be increased is reached, the oil pressure stage cannot be changed to the high pressure stage, resulting in an increase in the period during which the oil pressure is lower than the required pressure. The reliability of the internal combustion engine may be reduced. In this regard, according to the above configuration, when the oil pressure stage is the low pressure stage, the oil pressure stage is changed to the high pressure stage when the engine state quantity becomes equal to or greater than the predetermined value. There is no problem that the oil pressure stage cannot be changed to the high pressure stage even when the engine is in a state where the pressure should be increased.

  In the above configuration, if the predetermined period is set unnecessarily long, the oil pressure stage does not become the low pressure stage even when the engine pressure is not increased, and the oil pressure is not increased. As a result of an increase in the period during which the pressure is unnecessarily high, the fuel consumption may deteriorate. For this reason, the predetermined period is set to be long until the frequency of fluctuation of the engine state quantity including the predetermined value is low and the occurrence of abnormal noise or vibration due to the change in the operation mode of the pressure stage switching mechanism is not a problem. If this is done, the fuel efficiency will be deteriorated.

  From this, when it is estimated that the fluctuation frequency of the engine state quantity including the predetermined value is equal to or higher than the predetermined frequency, if the predetermined period is set to be longer than the case where the frequency is not, the predetermined period is It is possible to suppress the wasteful deterioration of fuel consumption due to the unnecessarily long setting. Therefore, the predetermined period can be appropriately set according to the frequency of change of the operation mode of the pressure stage switching mechanism 20.

  The pressure stage switching mechanism according to the present invention is not limited to the one exemplified in the above embodiment, and switches the pressure stage of oil supplied to each part of the engine between the high pressure stage and the low pressure stage. If there is, it can be changed to any configuration.

  DESCRIPTION OF SYMBOLS 11 ... Main supply passage, 12 ... Oil pan, 13 ... Oil strainer, 14 ... Oil pump, 15 ... Oil filter, 16 ... Relief passage, 20 ... Pressure stage switching mechanism, 21 ... Relief valve, 22 ... Housing, 22A ... Bottom , 22B ... end, 22C ... inlet side through hole, 22D ... outlet side through hole, 22E ... introduction through hole, 23 ... storage chamber, 23C ... inlet part, 23D ... outlet part, 23E ... introduction part, 24 ... variable Member 24A ... Bottom, 24B ... End, 24C ... Inlet side communicating hole, 24D ... Outlet side communicating hole, 25 ... Valve body, 26 ... Fixing member, 26A ... Expanded portion, 26B ... Reduced diameter portion, 27 ... Spring, DESCRIPTION OF SYMBOLS 28 ... Introduction channel | path, 29 ... Switching valve, 30 ... Electronic control unit (predetermined value setting means, predetermined period setting means), 41 ... Engine rotational speed sensor, 42 ... Intake air amount sensor, 43 ... Cooling water temperature sensor 43, 44 ... acceleration Sensor, 45 ... vehicle speed sensor.

Claims (12)

A pressure stage switching mechanism that switches the pressure stage of oil supplied to each part of the engine between a high pressure stage and a low pressure stage, and controls the oil pressure by switching the oil pressure stage according to the engine state quantity. In a hydraulic control device for an internal combustion engine,
When the oil pressure stage is a low pressure stage, the oil pressure stage is changed to a high pressure stage when the engine state quantity is equal to or greater than a first predetermined value, while the oil pressure stage is changed to a high pressure stage. And the oil pressure stage is changed to a low pressure stage when an engine state quantity becomes equal to or less than a second predetermined value smaller than the first predetermined value. . The hydraulic control apparatus for an internal combustion engine according to claim 1,
Predetermined value setting means for variably setting at least one of the first predetermined value and the second predetermined value;
The predetermined value setting means sets the predetermined value so that the degree of divergence between the first predetermined value and the second predetermined value becomes a predetermined degree. When it is estimated that the frequency of the first frequency is equal to or higher than the predetermined frequency, the predetermined values are set so that the degree of divergence between the first predetermined value and the second predetermined value is larger than that when the frequency is An oil pressure control apparatus for an internal combustion engine. The hydraulic control apparatus for an internal combustion engine according to claim 2,
The hydraulic control apparatus for an internal combustion engine, wherein the predetermined value setting means estimates the frequency of fluctuation of the engine state quantity based on an engine operating state. In the hydraulic control device for an internal combustion engine according to claim 2 or 3,
The internal combustion engine is mounted on the vehicle,
The said predetermined value setting means estimates the frequency of the fluctuation | variation of the said engine state quantity based on a vehicle running state. The hydraulic control apparatus of the internal combustion engine characterized by the above-mentioned. In the internal combustion engine hydraulic control apparatus according to any one of claims 2 to 4,
The predetermined value setting means changes the degree of divergence between the first predetermined value and the second predetermined value by variably setting only the second predetermined value. apparatus. A pressure stage switching mechanism that switches the pressure stage of oil supplied to each part of the engine between a high pressure stage and a low pressure stage, and controls the oil pressure by switching the oil pressure stage according to the engine state quantity. In a hydraulic control device for an internal combustion engine,
When the oil pressure stage is a low pressure stage, the oil pressure stage is changed to a high pressure stage when the engine state quantity exceeds a predetermined value, while the oil pressure stage is a high pressure stage. The oil pressure control apparatus for an internal combustion engine, wherein the oil pressure stage is changed to a low pressure stage when the state where the engine state quantity is below the predetermined value has continued for a predetermined period. The internal combustion engine hydraulic control apparatus according to claim 6,
A predetermined period setting means for variably setting the predetermined period;
The predetermined period setting means sets the predetermined period longer when the frequency of the fluctuation of the engine state quantity including the predetermined value is estimated to be equal to or higher than the predetermined frequency, compared to the case where it is not so. Hydraulic control device for an internal combustion engine. The internal combustion engine hydraulic control apparatus according to claim 7,
The hydraulic control device for an internal combustion engine, wherein the predetermined period setting means estimates a frequency of fluctuation of the engine state quantity based on an engine operating state. In the internal combustion engine hydraulic control apparatus according to claim 7 or 8,
The internal combustion engine is mounted on the vehicle,
The hydraulic control device for an internal combustion engine, wherein the predetermined period setting means estimates the frequency of fluctuation of the engine state quantity based on a vehicle running state. In the internal combustion engine hydraulic control apparatus according to any one of claims 1 to 9,
A hydraulic control apparatus for an internal combustion engine, wherein the engine state quantity includes an engine rotational speed. The internal combustion engine hydraulic control apparatus according to claim 10,
The internal combustion engine is a gasoline engine;
An internal combustion engine hydraulic control apparatus comprising an engine load as the engine state quantity. The internal combustion engine hydraulic control apparatus according to claim 10,
The internal combustion engine is a diesel engine;
A hydraulic control apparatus for an internal combustion engine, wherein the engine state quantity includes a fuel injection quantity.

Images