JP2007002682A - Hydraulic device of internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hydraulic device of an internal combustion engine capable of maintaining the filtering function of a filter provided in an oil passage of an electric oil pump for a long time, and avoiding an enlargement of the electric oil pump in which an increase of pumping pressure losses attributable to clogging of the filter is assumed. <P>SOLUTION: The hydraulic device comprises a mechanical oil pump 11 which is connected to and driven by an internal combustion engine 10, an electric oil pump 21 to be driven by a motor 20, an oil pan 30 to which the mechanical oil pump 11 and the electric oil pump 21 are connected, and a control unit 40 for controlling the operation of the electric oil pump 21 by controlling the motor 20. A strainer is provided in an oil passage 22 of the electric oil pump 21, and when the strainer is choked up, the control unit 40 reverses the electric oil pump 21 to perform the back-washing while the mechanical oil pump 11 is in operation. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a hydraulic apparatus for an internal combustion engine including an engine-driven mechanical oil pump and an electric oil pump.

  In an internal combustion engine, oil in an oil pan is sucked by a pump and discharged with a predetermined hydraulic pressure so that the lubricating part of the internal combustion engine is supplied as lubricating oil and to the hydraulic actuator as hydraulic oil. Yes. And the oil supplied to each part in this way is returned again to the oil pan through the oil passage. Since foreign matter such as wear metal powder may be mixed in the oil, the hydraulic device is provided with a filter such as a filter paper filter or a strainer in order to filter and capture the oil. Here, when the amount of foreign matter trapped in such a filter increases excessively, that is, when clogging progresses, the flow resistance when oil passes through the filter increases, and the filtration function also increases. It will fall. Therefore, in such a case, the filter function is restored by replacing the filter.

  Conventionally, as a pump of such a hydraulic device, an engine-driven mechanical oil pump that is driven and connected to an output shaft of an internal combustion engine has been used. However, although this mechanical oil pump can generate a relatively large discharge pressure when the rotational speed of the internal combustion engine rises above a predetermined rotational speed, the rotational speed of the internal combustion engine such as immediately after the engine is started. When the pressure is low, the discharge pressure may be extremely reduced, and the required oil pressure generation capacity may not be ensured.

Therefore, it is conceivable that an electric oil pump driven by a motor or the like is provided separately from the engine-driven mechanical oil pump, and these are used in combination. That is, when the rotational speed of the internal combustion engine decreases and the discharge pressure of the mechanical oil pump decreases, the required oil pressure is secured by this electric oil pump, thereby generating the oil pressure necessary for lubrication and hydraulic actuator operation. To be able to.
Japanese Utility Model Publication No. 07-017911

  By the way, in the case where the configuration in which the electric oil pump is provided separately from the mechanical oil pump as described above, the electric oil pump does not cause foreign matter biting or the like separately from the mechanical oil pump filter. It is necessary to newly provide another filter corresponding to the electric oil pump. Therefore, in the configuration in which the mechanical oil pump and the electric oil pump are used together in this way, the filter for the mechanical oil pump is replaced periodically, and the same applies to the filter for the electric oil pump. It will be necessary to perform replacement work. On the other hand, in order not to perform such replacement work or to eliminate it for as long as possible, it is possible to perform predetermined discharge even in a state where the pressure loss increases due to the clogging of the filter. In order to secure the pressure, a large electric oil pump that assumes such a clogged state in advance must be employed.

  Thus, in the configuration in which the electric oil pump is used in addition to the mechanical oil pump, the filter must be performed separately from the replacement work of the filter of the mechanical oil pump. In order to suppress the conversion, there is a disadvantage that the replacement work must be frequently performed.

  For example, Patent Document 1 describes a hydraulic device having a so-called backwashing function that periodically reverses the direction of oil flowing through a filter to remove foreign matter clogged in the filter with the flowing oil. . Certainly, according to this device, foreign substances clogged in the filter of the electric oil pump can be temporarily removed by backwashing, but the foreign substances are captured again by the filter during normal operation of the electric oil pump. Will come to be. For this reason, in the apparatus, it is necessary to frequently execute the backwashing process, and there is no denying that there is room for improvement in this respect.

  The present invention has been made in view of such circumstances, and the purpose of the present invention is to maintain the filtration function of the filter provided in the oil passage of the electric oil pump for a long period of time, thereby clogging the filter. An object of the present invention is to provide a hydraulic apparatus for an internal combustion engine that can avoid an increase in the size of an electric oil pump that assumes an increase in the pumping loss due to this.

Hereinafter, means for achieving the above-described object and its operation and effects will be described.
The invention according to claim 1 is an engine-driven mechanical oil pump and electric oil pump connected to an oil pan, a filter separately provided in an oil passage corresponding to each oil pump, and the electric oil A hydraulic unit for an internal combustion engine comprising a control unit for controlling operation of the pump, wherein the control unit reverses the direction of oil flow with respect to the filter of the electric oil pump during operation of the mechanical oil pump. In addition, a backwash process for controlling the operation of the electric oil pump is executed.

  According to this configuration, by performing the backwash process, the foreign matter clogged in the filter of the electric oil pump is removed from the filter and returned to the oil pan, and then sucked into the mechanical oil pump to be finally obtained. It is captured by the filter of the mechanical oil pump. And by performing such a backwash process, even if the filter is clogged about an electric oil pump, this can be eliminated or relieved appropriately. For this reason, about the enlargement of the electric oil pump which can maintain the filtration function for the filter provided in the oil passage of the electric oil pump for a long period of time, and the increase in the pressure loss due to the clogging of the filter is assumed. Will also be able to avoid this. In addition, since the clogging of the filter of the electric oil pump is appropriately eliminated as described above, the necessity for replacing the filter is extremely low.

  According to a second aspect of the present invention, in the hydraulic apparatus for an internal combustion engine according to the first aspect, the filter of the mechanical oil pump is set more finely than the filter of the electric oil pump. .

  According to this configuration, the foreign matter removed from the filter of the electric oil pump by the backwash process is sucked by the mechanical oil pump and is captured by the fine filter. In this way, foreign matter is captured by the filter of the mechanical oil pump, so that foreign matter released from the filter of the electric oil pump is captured by the filter again and clogging is suppressed as much as possible. Will be able to.

  According to a third aspect of the present invention, in the hydraulic apparatus for an internal combustion engine according to the first or second aspect, each suction port of the mechanical oil pump and the electric oil pump is sucked into the electric oil pump during the backwash process. The oil discharged from the port is arranged in the oil pan in close proximity so that it flows to the suction port side of the mechanical oil pump and flows into the suction port.

  According to this configuration, oil containing foreign matter discharged from the suction port of the electric oil pump during backwashing can be efficiently flowed into the suction port of the mechanical oil pump and captured by the filter. It is possible to suppress clogging by suppressing the foreign matter from being captured again by the filter of the oil pump.

  According to a fourth aspect of the present invention, in the hydraulic apparatus for an internal combustion engine according to any one of the first to third aspects, the filter of the mechanical oil pump is located downstream of the suction port of the mechanical oil pump. The filter is provided with a separate filter, and the separate filter is attached to the suction port of the mechanical oil pump so as to cover the suction port of the electric oil pump. I have to.

  According to this configuration, foreign substances contained in the oil discharged from the suction port of the electric oil pump during backwashing are prevented from being scattered in the oil pan by the separate filters provided in the mechanical oil pump. The foreign matter can be sucked from the suction port of the mechanical oil pump and captured by the filter of the mechanical oil pump.

  According to a fifth aspect of the present invention, in the hydraulic apparatus for an internal combustion engine according to any one of the first to fourth aspects, the electric oil pump operates using a motor as a drive source, and the control unit During the backwash process, the motor is rotated in the direction opposite to that during normal operation.

  According to the configuration, unlike the configuration in which a flow direction reversing mechanism including, for example, an oil passage and a flow path switching valve is provided and the direction of oil flow with respect to the filter is reversed through the mechanism, the electric oil pump The backwashing process can be executed through extremely simple operation switching such as reverse rotation of the drive motor, and the configuration of the hydraulic device can be simplified.

The invention according to claim 6 is the hydraulic apparatus for an internal combustion engine according to any one of claims 1 to 5,
When determining that the flow path resistance of the filter of the electric oil pump is greater than or equal to a predetermined value, the control unit determines that the flow path resistance is greater than or equal to a predetermined value by the determination means The backwash process is performed.

  According to this configuration, the magnitude of the flow path resistance of the filter having a correlation with the degree of clogging of the filter of the electric oil pump is determined, and when this increases, clogging that cannot be ignored occurs in the filter. Judgment can be made and backwashing can be performed. Therefore, when clogging progresses in the filter of the electric oil pump, the backwash process can be surely executed, and the clogging can be effectively suppressed.

  According to a seventh aspect of the present invention, in the hydraulic apparatus for an internal combustion engine according to the sixth aspect, the determination means has the flow path resistance equal to or greater than a predetermined value when the cumulative operating period of the electric oil pump has reached a predetermined period. It is determined that it is.

  While the electric oil pump is in operation, the amount of foreign matter trapped in the filter gradually increases and clogging progresses. In this regard, in the above configuration, when the cumulative operation period of the electric oil pump reaches a predetermined period, the backwash process is performed again. Therefore, by appropriately setting this predetermined period according to the clogging progress speed, the backwash process can be executed reliably when clogging in the filter of the electric oil pump progresses, and this is solved. Alternatively, it can be relaxed. The “cumulative operation period of the electric oil pump” may be a time having a correlation with the total amount of foreign matter captured by the filter that increases with the operation of the electric oil pump.

  In the same configuration, when the electric oil pump uses a motor as its driving force, a value obtained by weighting the operation time according to the rotation speed of the motor may be integrated, and this may be used as the cumulative operation period. . The higher the rotation speed of the motor, the greater the amount of oil sucked by the electric oil pump and the more foreign matter is trapped by the filter. According to the above configuration, the degree of clogging of the filter is thus increased. It is possible to set the execution time of the backwash process in consideration of the fact that the temperature changes depending on the rotation speed.

  According to an eighth aspect of the present invention, in the hydraulic apparatus for an internal combustion engine according to the sixth aspect, the electric oil pump operates using a motor as a drive source, and the determination means detects a value of a current flowing through the motor. When the current value is equal to or greater than the predetermined current value, it is determined that the flow path resistance is equal to or greater than the predetermined value.

  When clogging in the filter of the electric oil pump progresses, it becomes difficult for oil to pass through the filter, so the load on the motor that drives the electric oil pump increases and the value of the current flowing through the motor increases. .

  In this regard, according to the above configuration, the fact that the clogging of the filter progresses and the oil is difficult to flow is based on the fact that the current value flowing through the motor is equal to or greater than the predetermined current value. It can be detected properly.

  According to a ninth aspect of the present invention, in the hydraulic apparatus for an internal combustion engine according to the eighth aspect, the discharge capacity of the electric oil pump is changed by changing a voltage applied to the motor in accordance with an engine operating state. The determination means sets the predetermined current value such that the higher the applied voltage of the motor, the higher the predetermined current value.

  In addition, when the discharge capacity of the electric oil pump is changed by changing the applied voltage of the motor according to the engine operating state, the value of the current flowing to the motor is not limited to the external load acting on this. It also changes depending on the applied voltage. In this regard, according to the above configuration, the predetermined current value is variably set according to the voltage applied to the motor, so that the state in which the filter is clogged can be detected more accurately. it can.

  According to a tenth aspect of the present invention, in the hydraulic apparatus for an internal combustion engine according to the eighth or ninth aspect, the determination means includes an estimation means for estimating the viscosity of the oil, the lower the estimated oil viscosity is. The predetermined current value is set so that the predetermined current value becomes low.

  In addition, the flow path resistance of the filter also changes depending on the viscosity of the oil passing therethrough, and thus the external load of the electric oil pump also changes. In this regard, according to the above configuration, the predetermined current value is variably set according to the viscosity of the oil, so that the state in which the filter is clogged can be detected more accurately.

  The invention according to claim 11 further includes prohibiting means for estimating the viscosity of the oil and prohibiting the execution of the backwash process when the oil viscosity is equal to or higher than a predetermined viscosity. The internal combustion engine hydraulic system.

  According to this configuration, when the external load of the motor is increased due to the high viscosity of the oil, it is erroneously determined that this is due to the clogging in the filter, and the error It can be avoided that an unnecessary backwash process is performed based on the determination result.

  According to a twelfth aspect of the present invention, in the hydraulic apparatus for an internal combustion engine according to any one of the first to eleventh aspects, the control unit monitors the rotational speed of the internal combustion engine so that the rotational speed of the internal combustion engine is predetermined. The backwashing process is executed on condition that the rotation speed is exceeded.

  The higher the rotational speed of the internal combustion engine, the higher the suction capacity of the mechanical oil pump driven thereby, and the amount of oil sucked into the mechanical oil pump per hour also increases. Therefore, according to the above configuration, since the backwash process is performed when the suction capacity of the mechanical oil pump is high, foreign matter discharged from the filter of the electric oil pump is captured by the filter of the mechanical oil pump. Without remaining in the oil pan, the foreign matter can be efficiently captured by the filter of the mechanical oil pump.

  A thirteenth aspect of the present invention is the internal combustion engine hydraulic apparatus according to any one of the first to twelfth aspects, wherein the filter of the electric oil pump is attached to an oil suction port of the electric oil pump. Yes.

According to this configuration, foreign matters in the filter can be effectively removed by the oil flowing out from the suction port of the electric oil pump during the backwash process.
According to a fourteenth aspect of the present invention, in the hydraulic apparatus for an internal combustion engine according to the thirteenth aspect, the filter of the electric oil pump is a mesh strainer, and the filter of the mechanical oil pump is a discharge of the mechanical oil pump. It is assumed that the filter is a filter paper type filter disposed on the downstream side of the outlet.

  In addition, as described in claim 14, the filter of the electric oil pump is a mesh-shaped stray. The filter of the mechanical oil pump is a filter paper disposed downstream of the discharge port of the mechanical oil pump. It is desirable to employ each of the formula filters.

(First embodiment)
Hereinafter, an embodiment of a hydraulic apparatus for an internal combustion engine according to the present invention will be described with reference to FIGS.

  FIG. 1 is a schematic diagram schematically showing the structure of a hydraulic device of the internal combustion engine 10. As shown in FIG. 1, the hydraulic apparatus includes an electric oil pump 21 driven by a motor 20 in addition to a mechanical oil pump 11 driven by an output shaft (not shown) of the internal combustion engine 10. . The mechanical oil pump 11 is connected to the oil pan 30 and the internal combustion engine 10 by an oil passage 12. Similarly, the electric oil pump 21 is connected to the oil pan 30 and the internal combustion engine 10 by another oil passage 22. The oil sucked from the oil pan 30 by these oil pumps 11 and 21 is pressure-fed and supplied to the lubrication part of the internal combustion engine 10 and various actuators through the oil passages 12 and 22 with a predetermined pressure.

  FIG. 2 is an enlarged partial sectional view showing the vicinity of the suction ports 13 and 23 of the mechanical oil pump 11 and the electric oil pump 21. The suction ports 13 and 23 of the mechanical oil pump 11 and the electric oil pump 21 are both located in the oil pan 30. In the vicinity of the suction port 13 of the mechanical oil pump 11, a mesh-like strainer 14 is attached so as to cover the suction port 13. Similarly, a mesh-like strainer 24 is attached in the vicinity of the suction port 23 of the electric oil pump 21 so as to cover the suction port 23.

  The suction port 23 of the electric oil pump 21 and the strainer 24 attached to the suction port 23 are arranged close to the inside so as to be covered by the strainer 14 of the mechanical oil pump 11. Among the suction ports 13 and 23 of the mechanical oil pump 11 and the electric oil pump 21, the suction port 13 of the mechanical oil pump 11 is opened toward the suction port 23 side of the electric oil pump 21. Further, the strainer 24 of the electric oil pump 21 has a finer mesh size than the strainer 14 of the mechanical oil pump 11. When the oil pumps 11 and 21 are operated, the oil in the oil pan 30 is sucked into the oil pumps 11 and 21 after foreign matters contained therein are captured by the strainers 14 and 24.

  Further, a filter paper type filter 15 is provided in the oil passage 12 of the mechanical oil pump 11 between the downstream portion of the mechanical oil pump 11, that is, between the engine oil pump 11 and the internal combustion engine 10. The eyes of the filter 15 are set finer than the strainer 14 of the mechanical oil pump 11. Therefore, even if small foreign matter that cannot be captured by the strainer 14 is sucked into the mechanical oil pump 11 and discharged from the mechanical oil pump 11, most of the foreign matter is captured by the filter 15 before being supplied to the internal combustion engine 10. .

  The hydraulic apparatus also includes a control unit 40 for controlling the operation of the electric oil pump 21. The oil pan 30 is provided with an oil temperature sensor 31 that detects the temperature of the oil stored in the oil pan 30. A rotation speed sensor 32 that detects the rotation speed of the internal combustion engine 10 is provided near the output shaft of the internal combustion engine 10. The detection signals of these sensors 31 and 32 are taken into the control unit 40. In addition, the control unit 40 monitors the current value flowing through the motor 20 when a voltage is applied. This current value is also taken into the control unit 40 together with the detection signal.

  The control unit 40 adjusts the direction and magnitude of the voltage applied to the motor 20 based on the detection values of the sensors 32 and 31 and the current value of the motor 20, and starts and stops the operation of the electric oil pump 21. In addition, the oil discharge pressure and the like are controlled. The control unit 40 includes a memory 41 that stores and holds a program for executing such control, a calculation map, data calculated when the control is executed, and the like.

  In the hydraulic device configured as described above, when the engine speed is low, such as when the engine is started, when the mechanical oil pump 11 cannot obtain a sufficient discharge pressure, or when a high hydraulic pressure is required in the hydraulic actuator, etc. Then, the electric oil pump 21 is operated. Alternatively, the insufficient discharge pressure is compensated by increasing the rotation speed of the motor 20 to increase the discharge pressure.

  Here, when the operation period of the electric oil pump 21 becomes longer and the amount of foreign matter captured by the strainer 24 increases and clogging progresses, the flow resistance when the oil passes through the strainer 24 increases. In addition, the filtering function is also lowered. Therefore, the following backwash process is performed.

  That is, in this process, the direction of the voltage applied to the motor 20 is reversed, the direction of rotation is reversed, and the suction / discharge direction of the electric oil pump 21 is reversed, so that the oil is directed from the suction port 23 toward the strainer 24. To discharge. As a result, the foreign matter clogged in the strainer 24 by the discharged oil is separated from the strainer 24 and is sucked from the suction port 13 of the mechanical oil pump 11 and discharged from the mechanical oil pump 11 to be filtered. Captured.

Hereinafter, the backwash process will be described with reference to FIG.
FIG. 3 is a flowchart showing the execution procedure of the backwash process. A series of processing shown in this flowchart is repeatedly executed by the control unit 40 with a predetermined period.

  In this series of processes, it is first determined whether or not the rotational speed NE of the internal combustion engine 10 is equal to or higher than a predetermined rotational speed NEST (step S100). Accordingly, it is determined whether the mechanical oil pump 11 is in operation and whether the mechanical oil pump 11 has sufficient suction capability to suck in foreign matter that has been detached from the strainer 24 by backwashing.

  Here, when it is determined that the rotational speed NE of the internal combustion engine 10 is equal to or higher than the predetermined rotational speed NEST (step S100: YES), it is next determined that the flow path resistance of the strainer 24 is equal to or higher than the predetermined value. It is determined by the determination means whether or not the strainer 24 is clogged (steps S110 to S130). When clogging of the strainer 24 progresses and the flow path resistance increases, the current value CEP of the motor 20 increases accordingly. For this reason, here, when the current value CEP of the motor 20 is equal to or greater than a preset threshold value CST, it is determined that clogging has progressed, and the backwash process is executed under this condition. Here, the threshold value CST is set to a value higher than the maximum current value of the motor 20 when the electric oil pump 21 is operated in a state where the strainer 24 is not clogged.

  Further, the current value of the motor 20 changes according to the applied voltage applied to the motor 20. That is, the higher the applied voltage, the higher the current value CEP of the motor 20, and accordingly, the threshold value CST is set to a higher value.

  Furthermore, this maximum current value also changes depending on the viscosity of the oil. That is, the higher the oil viscosity is, the more load is applied to the motor 20, and the current value also increases. For this reason, here, the threshold value CST is variably set according to the oil temperature THO. Specifically, the threshold CST is set to a higher value as the oil temperature THO is lower, that is, as the viscosity of the oil is higher and the viscosity resistance is higher.

  In determining the clogging, first, the oil temperature THO is read (step S110). Next, a threshold value CST is calculated based on the applied voltage V of the motor 20 and the oil temperature THO (step S120). FIG. 4 is a calculation map showing the relationship between the applied voltage V and the oil temperature THO and the threshold value CST. This calculation map is obtained in advance based on experiments and the like, and is stored in the memory 41 as a calculation map.

Next, it is determined whether or not the current value CEP of the motor 20 is greater than or equal to the threshold value CST (step S130).
Here, when it is determined that the current value CEP is equal to or greater than the threshold value CST (step S130: YES), the motor 20 is reversely rotated by reversing the direction of the applied voltage. In other words, by reversing the suction / discharge direction of the electric oil pump 21, the oil is discharged from the suction port 23 toward the strainer 24, and the back washing process is performed to remove the foreign matter clogged in the strainer 24 (step). S140). Here, if it is determined in the previous process that the current value CEP is equal to or greater than the threshold value CST, the backwash process is continued until a predetermined period elapses. This predetermined period is set to a period during which most of the foreign matter clogged in the strainer 24 can be removed through the backwash process.

  After the backwash process is completed, or when it is determined that the rotational speed NE of the internal combustion engine 10 is less than the predetermined rotational speed NEST (step S100: NO), it is determined that the current value CEP is less than the threshold value CST. In the case where it has been done (step S130: NO), this series of processes is once terminated.

As described above, according to the present embodiment, the following effects can be obtained.
By performing the back washing process while the mechanical oil pump 11 is in operation, even if the strainer 24 becomes clogged, the electric oil pump 21 can be appropriately eliminated or alleviated. For this reason, the filtering function of the strainer 24 provided in the oil passage 22 of the electric oil pump 21 can be maintained for a long period of time, and the electric oil pump 21 is assumed to increase in pumping loss due to clogging of the strainer 24. This can be avoided also for the enlargement. As described above, since the clogging of the strainer 24 is appropriately eliminated, the necessity for replacing or working the strainer 24 is extremely low.

  The backwash process is executed on condition that the rotational speed of the internal combustion engine 10 is equal to or higher than a predetermined rotational speed. Therefore, the backwashing process is executed when the suction capacity of the mechanical oil pump 11 is high, and foreign matter discharged from the strainer 24 of the electric oil pump 21 is not captured by the filter 15 of the mechanical oil pump 11. It is possible to suppress the residual in the oil pan 30 as much as possible.

  In addition, since the suction port 13 of the mechanical oil pump 11 is opened toward the suction port 23 side of the electric oil pump 21, the oil containing the foreign matter detached from the strainer 24 of the electric oil pump 21 It becomes easy to flow to the suction port 13 side, and the foreign matter can be quickly sucked.

  Since the filter 15 of the mechanical oil pump 11 is a filter paper filter that has a finer mesh than the strainer 24 of the electric oil pump 21, foreign matter released from the strainer 24 by backwashing is sucked by the mechanical oil pump 11. , The fine filter 15 is captured. As described above, the foreign matter is captured by the filter 15 of the mechanical oil pump 11, so that the foreign matter detached from the strainer 24 is again captured by the strainer 24 and clogging can be suppressed as much as possible. Become.

  The oil discharged from the suction port 23 during backwashing treatment flows through the oil suction port 23 of the oil passage 22 of the electric oil pump 21 and the suction port 13 of the oil passage 12 of the mechanical oil pump 11 to the suction port 13 side. Are arranged in the oil pan 30 in close proximity so as to flow into the suction port 13. Therefore, oil containing foreign matter discharged from the strainer 24 during the backwash process can be efficiently introduced into the suction port 13 of the mechanical oil pump 11 and captured by the filter 15. For this reason, it is possible to suppress the clogging by suppressing the foreign matter from being captured again by the strainer 24.

  Since the strainer 14 is provided at the suction port 13 so as to cover the strainer 24 of the electric oil pump 21, foreign matter contained in the oil discharged from the strainer 24 is scattered in the oil pan 30 during the backwash process. The foreign matter can be sucked from the suction port 13 and captured by the filter 15 of the mechanical oil pump 11.

  The backwash process of the strainer 24 is performed by rotating the motor 20 in the reverse direction. For this reason, unlike a configuration in which a flow direction reversing mechanism including, for example, an oil passage for backwashing and a flow path switching valve is provided and the direction of oil flow with respect to the strainer 24 is reversed through the mechanism, it is extremely simple. The backwash process can be executed through the method, and the simplification of the configuration of the hydraulic device can be achieved.

  By determining whether or not the current value of the motor 20 is greater than or equal to the threshold value, it can be detected that the strainer 24 is clogged and the oil is less likely to flow. Therefore, when clogging progresses to the strainer 24 of the electric oil pump 21, the backwash process can be reliably executed, and the clogging can be effectively suppressed.

Furthermore, since the threshold value is variably set according to the oil temperature, it is possible to more accurately detect a state in which the strainer 24 is clogged. That is, when the external load of the motor 20 is increased due to the high viscosity of the oil, it is erroneously determined that this is because clogging in the strainer 24 has progressed, and the erroneous determination result. It can be avoided that an unnecessary backwash process is performed based on the above.
(Second Embodiment)
Hereinafter, a second embodiment of the present invention will be described. In the hydraulic apparatus according to the first embodiment, the current value of the motor 20 is monitored, and the flow path resistance of the strainer 24 is determined based on the current value. However, in the apparatus according to the present embodiment, Instead, the flow resistance is determined based on the cumulative operation period of the electric oil pump 21, which is different from the apparatus of the first embodiment. Hereinafter, this difference will be mainly described.

  As indicated by a two-dot chain line in FIG. 1, the control unit 40 is provided with a timer 42 that measures the cumulative operation period of the electric oil pump 21. The timer 42 measures the time during which the electric oil pump 21 is operating, that is, the voltage is applied to the motor 20. Note that this time count includes the time during which the electric oil pump 21 is normally operated and the time during which the backwash process is performed. Then, when the backwash process is executed for a predetermined period and completed, it is reset.

  FIG. 5 is a flowchart showing the execution procedure of the backwash process. A series of processing shown in this flowchart is repeatedly executed by the control unit 40 with a predetermined period. Of the processes shown in FIG. 5, those given the same step numbers as those in the flowchart of FIG. 3 are the same as those shown in FIG. Omit.

  As shown in FIG. 5, when it is determined that the rotational speed NE of the internal combustion engine 10 is equal to or higher than the predetermined rotational speed NEST (step S100: YES), the cumulative operation period TO of the electric oil pump 21 is determined from the timer 42. It is read (step S115).

  Next, it is determined whether or not the cumulative operation period TO is equal to or longer than the predetermined period TST (step S135). Here, the cumulative operation period TO has a correlation with the total amount of foreign matter captured by the strainer 24 since the previous backwash process was performed, and the predetermined period TST has a partial total capture amount. This is for determining that the increase in the flow path resistance of the strainer 24 cannot be ignored when the amount exceeds the predetermined amount. Therefore, when the cumulative operation period TO is equal to or longer than the predetermined period TST, it can be determined that the strainer 24 is clogged.

  When it is determined that the cumulative operation period TO is equal to or longer than the predetermined period TST (step S135: YES), a backwash process is executed (step S140). When this backwash process is completed, the cumulative operation period TO of the timer 42 is reset to “0” (step S150). After executing this reset process, or when it is determined that the rotational speed NE of the internal combustion engine 10 is not equal to or higher than the predetermined rotational speed NEST (step S100: NO), or in step S135, the cumulative operation period TO is not equal to or longer than the predetermined period TST. If it is determined (step S135: NO), this series of processing ends.

As described above, according to the present embodiment, the following effects can be obtained.
By monitoring the total amount of foreign matter captured by the strainer 24, that is, the degree of clogging, based on the cumulative operation period of the electric oil pump 21 measured from the end of the previous backwash process, the strainer 24 caused by such clogging is monitored. An increase in channel resistance can be detected by a simple technique. And by setting this predetermined period TST appropriately according to the progress speed of clogging, when the clogging in the strainer 24 of the electric oil pump 21 progresses, the backwash process can be executed reliably. It can be eliminated or alleviated.
(Third embodiment)
Hereinafter, a third embodiment of the present invention will be described. In the hydraulic apparatus according to the first embodiment, the threshold value CST to be compared with the current value CEP of the motor 20 is set based on the applied voltage V and the oil temperature THO. In the third embodiment, this threshold value is set. CST is set based only on the applied voltage V. When the viscosity of the oil is high and the viscosity resistance is large, the increase in the current value CEP is caused by the clogging of the strainer 24 or the load on the motor 20 increases due to the viscosity resistance of the oil. Since it cannot be determined whether it is caused by this, the backwash process is prohibited from being executed. Hereinafter, this difference will be mainly described.

  FIG. 6 is a flowchart showing the execution procedure of the backwash process. A series of processing shown in this flowchart is repeatedly executed by the control unit 40 with a predetermined period. Of the processes shown in FIG. 5, those given the same step numbers as those in the flowchart of FIG. 3 are the same as those shown in FIG. Omit.

  In this series of processes, the oil temperature THO can be read first (step S110). Next, it is determined whether or not the oil temperature THO is equal to or higher than a preset predetermined oil temperature THST (step S116).

  Here, the oil temperature THO has a correlation with the viscosity of the oil, and the predetermined oil temperature THST determines that the oil temperature is lower than the predetermined temperature and the influence of the viscous resistance applied to the motor 20 cannot be ignored. Is for. Therefore, when the oil temperature THO is equal to or higher than the predetermined oil temperature THST, it can be determined that the external load of the motor is increased due to the high viscosity of the oil.

  Here, when it is determined that the oil temperature THO is equal to or higher than the predetermined oil temperature THST (step S116: YES), the threshold CST is calculated based only on the applied voltage V of the motor 20 (step S120). Thereafter, the processing from step S130 is performed similarly to the processing in the first embodiment shown in FIG.

  After the backwash process (step S140) is completed, or when it is determined that the oil temperature THO is lower than the predetermined oil temperature THST (step S116: NO), it is determined that the current value CEP is lower than the threshold value CST. In the case where it has been done (step S130: NO), this series of processes is once terminated.

As described above, according to the present embodiment, the following effects can be obtained.
-According to the same configuration, when the external load of the motor is increased due to the high viscosity of the oil, it is erroneously determined that this is due to the progress of clogging in the filter. It is possible to avoid unnecessary backwash processing from being performed based on an erroneous determination result. Therefore, for example, at the time of engine cold start when the temperature of the oil decreases, the backwash process is executed even though it is necessary to compensate for the insufficient discharge pressure of the mechanical oil pump 11 by operating the electric oil pump 21. Can be avoided.

  In the first embodiment, in order to calculate the threshold value CST, a calculation map using the oil temperature THO and the applied voltage V as parameters is prepared, but in this embodiment, the calculation map Simplification, and consequently, the capacity of the memory 41 can be increased.

In the above embodiments, the following modifications may be made.
In the above embodiment, the motor is used as the drive source of the electric oil pump. However, a drive source other than the motor such as an electric actuator can be used.

  In the above embodiment, the means for reversing the direction of voltage application to the motor is shown as means for reversing the rotation direction of the electric oil pump. However, a gear is provided between the motor and the electric oil pump to switch the electric oil pump. The direction of rotation of the oil pump can also be reversed.

  -In above-mentioned embodiment, although the control part 40 was shown as a control part for exclusive use which controls operation | movement of an electric oil pump, the same process is performed to the electronic controller which controls the internal combustion engine comprehensively. An alternative is also possible.

  In the above embodiment, the oil suction port 23 of the oil passage of the electric oil pump and the suction port 13 of the oil passage of the mechanical oil pump are disposed close to each other in the oil pan. Even if the mouth 23 and the suction port 13 are not close to each other, the foreign matter of the strainer 24 can be removed and the progress of clogging can be suppressed.

  In the above embodiment, it has been shown that the strainer 24 is provided as a filter of the electric oil pump at the oil suction port 23. However, if the filter of the electric oil pump is in the oil passage 22, the oil suction port 23 other than the oil suction port 23 is provided. It can also be provided at the location.

  In the above embodiment, the strainer 14 is provided at the suction port 13 so as to cover the strainer 24 of the electric oil pump. However, the strainer 14 may be provided without covering the strainer 24. Moreover, it can also be set as the structure which does not provide the strainer 14. FIG.

  In the above embodiment, the filter paper type filter 15 finer than the strainer 24 is provided downstream from the mechanical oil pump 11, but the filter 15 can also be provided upstream from the mechanical oil pump 11. Moreover, it can also be set as filters, meshes, etc. other than a filter paper type filter, and can also make a thing coarser than the strainer 24 or more.

  In the above embodiment, the oil temperature is detected by the oil temperature sensor 31 provided in the oil pan as means for monitoring the oil viscosity, but has a correlation with the oil viscosity such as the water temperature of the internal combustion engine cooling water. The oil viscosity can be monitored by detecting the parameter.

  In the above embodiment, it is determined in step S100 whether or not the rotational speed NE of the internal combustion engine 10 is equal to or higher than the predetermined rotational speed NEST, but here it is determined only whether or not the internal combustion engine 10 is rotating. Even if it is determined that the mechanical oil pump 11 is in operation, the foreign matter detached from the strainer 24 can be sucked together with the oil.

  In the above embodiment, the higher the applied voltage, the higher the current value CEP of the motor of the electric oil pump. Accordingly, the threshold value CST is set to a higher value. Alternatively, a value higher than the maximum current value in a state where the strainer is not clogged may be set as the threshold value CST.

Note that the threshold value CST may be a constant value regardless of the oil temperature or the applied voltage.
In the above embodiment, the backwash process is continued until a predetermined period elapses, and this predetermined period is set to a period during which most of the foreign matter clogged in the strainer can be removed through the backwash process. However, for example, a period until the current value of the motor becomes smaller than the threshold value CST by a predetermined value or more may be set. When the predetermined period is set according to time, the predetermined period can be set longer as the viscosity of the oil is higher, that is, as the oil temperature THO is lower, according to the viscosity of the oil.

  In the above embodiment, the flow resistance of the strainer 24 is determined based on the cumulative operation period TO of the electric oil pump. Here, the time weighted with the operation time is added according to the rotation speed of the motor 20, and this is accumulated. The period TO may be set.

In the above embodiment, the cumulative operation period TO is reset at the end of the backwashing process. However, for example, the resetting process may be executed before the backwashing process is started.
In the above embodiment, the flow path resistance of the strainer 24 is determined based on the current value from the motor 20 or the cumulative operation period of the electric oil pump 21, but the upstream portion sandwiching the strainer 24 in the oil passage 22 The flow path resistance of the strainer 24 can also be determined by monitoring the hydraulic pressure difference in the downstream portion. In this case, when the hydraulic pressure difference is equal to or greater than a predetermined hydraulic pressure difference, it is determined that the flow path resistance is equal to or greater than a predetermined value.

  In the above embodiment, the cumulative operating period TO of the electric oil pump 21 is measured by time by providing the timer 42. However, the cumulative operating period TO is determined by measuring the cumulative rotational speed of the electric oil pump 21. You can also

  In the above embodiment, when it is determined that clogging is in progress (steps S130 and 135: YES), the backwash process (step S140) is immediately executed, but step S140 is performed. The backwash process may be executed separately from the timing of determination using the backwash process as the backwash process flag. By doing so, it is possible to hold back the backwash process when the hydraulic oil pump needs to generate hydraulic pressure.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a simplified diagram schematically showing an overall configuration of an embodiment of a hydraulic apparatus for an internal combustion engine according to the present invention. The fragmentary sectional view which expands and shows the suction inlet vicinity of each oil passage. The flowchart which shows the process sequence at the time of performing a backwash process about 1st Embodiment. The calculation map which shows the relationship between an applied voltage and oil temperature, and a threshold value. The flowchart which shows the process sequence at the time of performing a backwash process about 2nd Embodiment. The flowchart which shows the process sequence at the time of performing a backwash process about 3rd Embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Internal combustion engine, 11 ... Mechanical oil pump, 12, 22 ... Oil passage, 13, 23 ... Inlet, 14, 24 ... Strainer, 15 ... Filter, 20 ... Motor, 21 ... Electric oil pump, 30 ... Oil pan, DESCRIPTION OF SYMBOLS 31 ... Oil temperature sensor, 32 ... Rotation speed sensor, 40 ... Control part, 41 ... Memory, 42 ... Timer

Claims (14)

An engine-driven mechanical oil pump and an electric oil pump connected to the oil pan, a filter separately provided in an oil passage corresponding to each oil pump, and a control unit for controlling the operation of the electric oil pump; An internal combustion engine hydraulic device comprising:
The controller performs a backwash process for controlling the operation of the electric oil pump so that the direction of oil flow with respect to the filter of the electric oil pump is reversed during operation of the mechanical oil pump. A hydraulic device for an internal combustion engine. The hydraulic apparatus for an internal combustion engine according to claim 1,
The hydraulic device for an internal combustion engine, wherein the filter of the mechanical oil pump is set more finely than the filter of the electric oil pump. The hydraulic apparatus for an internal combustion engine according to claim 1 or 2,
The suction ports of the mechanical oil pump and the electric oil pump are configured such that oil discharged from the suction port of the electric oil pump during the backwash process flows into the suction port side of the mechanical oil pump and flows into the suction port. A hydraulic apparatus for an internal combustion engine, wherein the hydraulic apparatus is disposed in the oil pan in proximity to the oil pan. The hydraulic apparatus for an internal combustion engine according to any one of claims 1 to 3,
The mechanical oil pump has a filter provided downstream of the suction port of the mechanical oil pump, and further includes a separate filter from the filter, and the separate filter is the electric filter. A hydraulic apparatus for an internal combustion engine, which is attached to the suction port of the mechanical oil pump so as to cover the suction port of the oil pump. The hydraulic apparatus for an internal combustion engine according to any one of claims 1 to 4,
The electric oil pump operates using a motor as a drive source,
The control unit rotates the motor in a direction opposite to a normal time during the backwash process. The hydraulic apparatus for an internal combustion engine according to any one of claims 1 to 5,
A determination means for determining that the flow path resistance of the filter of the electric oil pump is a predetermined value or more;
The control unit performs the backwashing process when the determination unit determines that the flow path resistance is equal to or greater than a predetermined value. The hydraulic apparatus for an internal combustion engine according to claim 6,
The determination unit determines that the flow path resistance is equal to or greater than a predetermined value when a cumulative operation period of the electric oil pump reaches a predetermined period. The hydraulic apparatus for an internal combustion engine according to claim 6,
The electric oil pump operates using a motor as a drive source, and the determination means detects a current value flowing through the motor, and when the current value is equal to or greater than a predetermined current value, the flow path resistance is equal to or greater than a predetermined value. A hydraulic device that uses both a mechanical oil pump and an electric oil pump. The hydraulic apparatus for an internal combustion engine according to claim 8,
The electric oil pump is one whose discharge capacity is changed by changing the applied voltage of the motor according to the engine operating state,
The determination unit sets the predetermined current value so that the predetermined current value becomes higher as the applied voltage of the motor is higher. The hydraulic apparatus for an internal combustion engine according to claim 8 or 9,
The determination means includes an estimation means for estimating the viscosity of the oil, and sets the predetermined current value so that the predetermined current value becomes lower as the estimated oil viscosity is lower. apparatus. The hydraulic apparatus for an internal combustion engine according to any one of claims 8 to 10, further comprising prohibiting means for estimating the viscosity of the oil and prohibiting the execution of the backwash process when the oil viscosity is equal to or higher than a predetermined viscosity. The hydraulic apparatus for an internal combustion engine according to any one of claims 1 to 11,
The control unit monitors the rotational speed of the internal combustion engine and executes the backwash process on the condition that the rotational speed of the internal combustion engine is equal to or higher than a predetermined rotational speed. The hydraulic apparatus for an internal combustion engine according to any one of claims 1 to 12,
The hydraulic apparatus for an internal combustion engine, wherein the filter of the electric oil pump is attached to an oil suction port of the electric oil pump. The hydraulic apparatus for an internal combustion engine according to claim 13,
The filter of the electric oil pump is a mesh-shaped strainer, and the filter of the mechanical oil pump is a filter paper type filter disposed downstream of the discharge port of the mechanical oil pump. Hydraulic device for internal combustion engine.

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