JP2014105665A - Lubrication oil holding device of internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lubrication oil holding device of an internal combustion engine which holds lubrication oil of the internal combustion engine by an electrically-driven oil pump during stopping an internal combustion engine, and which actuates the electrically-driven oil pump when pressure of the lubrication oil in a lubrication part is reduced.SOLUTION: The lubrication oil holding device comprises: a mechanical oil pump 5 driven by an internal combustion engine 1 and pressure-feeding lubrication oil; a first check valve 7 interposed at an intermediate part of a first oil passage 51 for coupling each sliding part 22 of an internal combustion engine and the mechanical oil pump, and for preventing the lubrication oil from reversely flowing toward the mechanical oil pump; an electrically-driven oil pump 6 having a second oil passage 62 coupled with a downstream side of the first check valve; a second check valve 8 for preventing the lubrication oil from reversely flowing toward the electrically-driven oil pump in the second oil passage; and a control device 10 for controlling an operation of the electrically-driven oil pump. While the internal combustion engine is stopped, when the lubrication oil at each sliding part is reduced, the control device 10 actuates the electrically-driven oil pump, so as to pressure-feed the lubrication oil to each sliding part.

Description

  The present invention relates to a lubricating oil retaining device for an internal combustion engine that retains the lubricating oil of the internal combustion engine even when the internal combustion engine is stopped, in which the internal combustion engine is frequently stopped and started.

Recently, a vehicle equipped with an idle stop & start device has been put into practical use for fuel saving. The idle stop & start device automatically stops the internal combustion engine when the vehicle stops temporarily at intersections, railroad crossings, traffic control signals, etc., and implements fuel savings. Is a device that automatically starts the internal combustion engine.
However, since the internal combustion engine is operated at a high temperature, the lubricating oil that lubricates each sliding portion, which is the lubricating portion in the internal combustion engine, also has an action of cooling each sliding portion. Many are in circulation.

When the internal combustion engine is stopped and the drive of the mechanical oil pump is stopped, the lubricating oil filled in the lubricating part flows into the oil pan from the gap between the sliding parts of the lubricating part due to the weight of the lubricating oil. Lubricating oil in the sliding part may be lost.
As shown in FIG. 3C, when the internal combustion engine is stopped, the lubricating oil pressure P1 of the lubricating portion during operation of the internal combustion engine gradually decreases from time Ta to Te.
In this case, when the stop time T0 of the internal combustion engine is set, the lubricating oil pressure P is zero during the time T2.
When the stop time T0 has elapsed, the internal combustion engine starts at time Tc. Even if the internal combustion engine is restarted in this state, it takes time T3 until the lubricating oil pressure P of the lubricating portion is changed from 0 (zero) to P1.
During the time T3 until the lubricating oil from the mechanical oil pump driven by the internal combustion engine reaches each sliding portion, each sliding portion slides in a state where there is no lubricant and is insufficient.
In particular, in a vehicle equipped with an idle stop & start device, if the internal combustion engine is repeatedly stopped and restarted in a state where there is no or insufficient lubricating oil in the lubricating part, wear of each sliding part of the lubricating part, insufficient cooling, etc. , Causing problems that reduce the durability of the internal combustion engine.
Patent Document 1 is known as a technique for dealing with such a shortage of lubricating oil.

According to Patent Document 1, in a vehicle including a hydraulic device that uses hydraulic pressure from a mechanical oil pump that pumps hydraulic pressure by driving an internal combustion engine as hydraulic fluid, an electric oil pump coupled in parallel with the mechanical oil pump is provided. In addition, a device for automatically stopping and restarting the internal combustion engine is mounted without using the ignition key, and a low oil pressure is generated by an electric oil pump when the stop condition of the internal combustion engine is satisfied. When the restart condition of the internal combustion engine is satisfied, the electric oil pump is driven to generate a high hydraulic pressure. This is a technique for stopping the electric oil pump under a predetermined condition after restarting the internal combustion engine.
As a result, the necessary and sufficient hydraulic pressure is ensured with good timing when the internal combustion engine is restarted, the engagement state of the hydraulic clutch is maintained, and the shock associated with the engagement of the clutch is reduced.

JP 2002-106380 A

However, according to Patent Document 1, in the internal combustion engine automatic stop automatic starting device, the electric oil pump generates a low oil pressure as the internal combustion engine stop condition is satisfied, and the internal combustion engine restart condition is satisfied. Along with this, the electric oil pump generates a relatively high hydraulic pressure.
In other words, in order to maintain the engaged state of the hydraulic clutch, the discharge pressure of the electric oil pump is controlled in two stages, and it is a device that always operates at least when the internal combustion engine is stopped. There is a problem that there is a high possibility that a problem will occur in the durability of the oil pump and the cost of the entire apparatus due to the complexity of the control.

  The present invention has been made in view of the above-described problems of the prior art, and when the internal combustion engine is stopped, the electric oil pump holds the lubricating oil of the internal combustion engine, and the electric oil is supplied when the lubricating oil pressure of the lubricating portion decreases. It is an object of the present invention to provide a lubricating oil retaining device for an internal combustion engine that operates a hydraulic oil pump.

In order to achieve the above object, according to the present invention, in an internal combustion engine equipped with an idle stop & start device,
A mechanical oil pump that is driven by the internal combustion engine and pumps lubricating oil to a lubricating portion of the internal combustion engine;
A first check valve that is interposed in an intermediate portion of a first oil passage that connects the lubricating portion and the mechanical oil pump, and prevents the lubricating oil from flowing back to the mechanical oil pump side;
An electric oil pump having a second oil passage connected to the downstream side of the first check valve;
A second check valve for preventing the lubricating oil from flowing backward to the electric oil pump side downstream of the electric oil pump in the second oil passage;
A control device for controlling the operation of the electric oil pump,
When the internal combustion engine is stopped and the lubricating oil filled in the lubricating portion is reduced, the control device operates the electric oil pump to pump the lubricating oil to the lubricating portion. An internal combustion engine lubricating oil retaining device can be provided.

According to the present invention, even when the internal combustion engine is stopped, the lubricating oil can be held in the lubricating portion by the electric oil pump and the first and second check valves, so that the wear resistance and the cooling effect of the lubricating portion are improved. The durability of the internal combustion engine can be improved.
In addition, since the electric oil pump is operated when the lubricating oil decreases, the operation time of the electric oil pump is shortened, and the durability of the electric oil pump is improved and the power consumption by driving is reduced. The fuel consumption of the internal combustion engine can be reduced.

  In the present invention, it is preferable that the reduction of the lubricating oil is the reduction of the lubricating oil by using at least one of the lubricating oil pressure of the lubricating portion or the time after the elapse of a predetermined time after the internal combustion engine is stopped. Good.

  With this configuration, it is possible to predict the amount of lubricating oil flowing out from a lubricating oil pressure sensor (hydraulic sensor) that has been conventionally installed in an internal combustion engine or from a lubricating portion after a certain period of time has elapsed since the internal combustion engine stopped. Thus, since the electric oil pump is operated, the device is simplified and the cost of the device can be suppressed from increasing.

  In the present invention, it is preferable that the discharge amount of the electric oil pump is set to a constant pressure lower than the lubricating oil pressure generated in the lubrication part by the discharge amount of the mechanical oil pump.

  The operation of the electric oil pump is ON / OFF controlled by the control device, and when it is ON, it is preferably driven at a rated rotation so as to discharge the constant pressure.

With this configuration, it is not necessary to maintain the lubricating oil pressure when the internal combustion engine is operating while the internal combustion engine is stopped.
When the internal combustion engine is started, it is sufficient that the lubricating oil is held in the lubricating portion and the amount of lubricating oil necessary for lubricating the sliding portion is sufficient. By doing in this way, weight reduction by size reduction of an electric oil pump, cost reduction, and improvement in fuel consumption by suppressing power consumption can be achieved.

  In the present invention, it is preferable that the control device stops the electric oil pump when the internal combustion engine is started.

  By adopting such a configuration, by preventing the electric oil pump from rotating unnecessarily, it is possible to improve the durability of the electric oil pump and to reduce the fuel consumption of the internal combustion engine by suppressing the use of electric power.

  In the present invention, it is preferable that the control device provide a delay time until the electric oil pump stops after the internal combustion engine is started.

  With this configuration, after the internal combustion engine is started, the time from the mechanical oil pump until the lubricating portion reaches the lubricating oil pressure necessary for driving the internal combustion engine is minimized, and the wear resistance of the lubricating portion is improved. Can be improved.

  In this way, when the internal combustion engine is stopped, the electric oil pump holds the lubricating oil of the internal combustion engine, and the electric oil pump is operated when the lubricating oil pressure of the lubricating portion decreases, so that the internal combustion engine It is possible to provide a lubricating oil retaining device for an internal combustion engine that can improve durability, reduce weight by reducing the size of an electric oil pump, reduce cost, and improve fuel efficiency by suppressing power consumption.

1 is a schematic configuration diagram of an entire internal combustion engine to which an embodiment of the present invention is applied. The operation | movement flowchart for implementing this invention is shown. (A) is a change in lubricating oil pressure for stopping and starting the internal combustion engine of the lubricating portion according to the present invention, (B) is an enlarged view of a Z portion in (A), and (C) is a change in the lubricating oil pressure for stopping and starting the internal combustion engine in the prior art. FIG.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
However, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention only to specific examples unless otherwise specifically described. Only.

FIG. 1 is a schematic configuration diagram of an entire internal combustion engine to which the embodiment is applied.
1 shows an overall configuration diagram of an internal combustion engine. The internal combustion engine 1 is mounted on an internal combustion engine body 2, an oil pan 3 that is attached to the lower part of the internal combustion engine body 2, and stores lubricating oil that lubricates each part of the internal combustion engine body 2, and is driven by the internal combustion engine body 2. 3, the mechanical oil pump 5 that pumps up the lubricating oil in the oil gallery 3 and pumps the lubricating oil to an oil gallery 21 to be described later via the first oil passage 51, and the first oil passage 51 in the downstream of the mechanical oil pump 5. The first check valve 7 disposed on the side and configured to prevent the lubricating oil pumped from the mechanical oil pump 5 from flowing back to the mechanical oil pump 5 side and the lubricating oil pumped from the mechanical oil pump 5 to the internal combustion engine An oil gallery 21 to be supplied to each sliding portion 22 which is a lubricating portion in the main body 2 and a second oil passage 62 connected between the oil gallery 21 of the first oil passage 51 and the first check valve 7 are provided. Electric oil pump 6 and A second check that is disposed on the downstream side of the electric oil pump 6 in the oil passage 62 and prevents the lubricating oil pumped from the first oil passage 51 and the electric oil pump 6 from flowing back to the electric oil pump 6 side. A valve 8, a lubricating oil pressure detection sensor 9 that detects the lubricating oil pressure in the oil gallery 21, a rotation speed sensor 11 that detects the operating state of the internal combustion engine 1, and a control device 10 that controls the operation of the internal combustion engine 1; It has.
Reference numeral 21 denotes a radiator fan that sucks air passing through a radiator (not shown) that cools the cooling water in the internal combustion engine body 2.

The lubricating oil pressure detection sensor 9 is a sensor for issuing an alarm when the lubricating oil pressure in the oil gallery 21 becomes a specified value or less, and has been conventionally mounted and is also called a common name oil pressure switch. It is not a specially provided sensor.
The first check valve 7 stops the mechanical oil pump 5 when the internal combustion engine 1 stops. When the mechanical oil pump 5 is stopped, the lubricating oil pumped to the internal combustion engine body 2 side is prevented from flowing out (returning) from the gap of the mechanical oil pump 5 to the oil pan 3 side due to its own weight. .
Further, the first check valve 7 is configured so that when the electric oil pump 6 is operated after the internal combustion engine 1 is stopped, the lubricating oil discharged from the electric oil pump 6 is supplied to the oil pan via the mechanical oil pump 5. It is prevented from flowing out (returning) to the third side.

Similarly to the first check valve 7, the second check valve 8 also causes the lubricating oil pumped to the internal combustion engine body 2 side and the lubricating oil discharged from the mechanical oil pump 5 to pass through the second check valve 8. Through (returning to) the oil pan 3 side.
Therefore, the first check valve 7 and the second check valve 8 have a structure that seals the upstream side of the oil gallery 21 until the internal combustion engine 1 stops and the electric oil pump 6 operates (time). This has the effect of delaying the outflow of the lubricating oil from each sliding portion 22.

The control device 10 determines whether the operating state of the internal combustion engine 1, that is, the signal from the rotation speed sensor 11 that detects whether the internal combustion engine 1 is operating or stopped, and the lubricating oil pressure P in the oil gallery 21 is a threshold value ( When the specified value is equal to or less than P2, a signal from the lubricating oil pressure detection sensor 9 is input.
Further, when the control device 10 determines that the internal combustion engine 1 has stopped based on a signal from the rotational speed sensor 11, a timer (not shown) built in the control device 10 is activated.
When the measurement is started by the timer and a predetermined time elapses, the control device 10 issues a command to drive the drive motor 61 of the electric oil pump 6.
In the case of the present embodiment, the control device 10 is configured to obtain two pieces of information, that is, a lubricant pressure detection sensor 9 and a timer in order to operate the electric oil pump 6.
In the 2 information, when the timing for operating the electric oil pump 6 is different, the electric oil pump 6 is operated with priority given to the condition for operating the electric oil pump 6 first. ing.

Further, a certain time elapsed measured by the timer means that the internal combustion engine 1 is stopped, the mechanical oil pump 5 stops pumping the lubricating oil, and then the lubricating oil filling each sliding portion 22 is filled. A result obtained by actually measuring the time until the lubricating oil pressure of each sliding portion 22 reaches the specified value P2 with a test device is used.
The time until the lubricating oil pressure reaches the specified value P2 varies depending on the temperature of the lubricating oil and the gap between the sliding portions 22.
However, the gaps between the sliding portions 22 are managed with high accuracy in the manufacturing process of the internal combustion engine 1, and the lubricating oil is kept at a constant temperature by an oil cooler (not shown).
Therefore, the variation by each internal combustion engine 1 is small, and the object of the present invention can be achieved even if the drive control of the electric oil pump 6 is performed only by the timer.

The operation of the control device will be described with reference to FIGS. 2 and 3A and 3B.
FIG. 2 shows an operation flow chart for carrying out the present invention, FIG. 3 (A) shows a change in lubricating oil pressure when the internal combustion engine of the lubricating part is stopped and started according to the present invention, and (B) is (A). The enlarged view of the Z section is shown.
This operation flow will be described based on a vehicle equipped with an idle stop & start device.
In step S1, the control of the present invention starts. In step S2, when the vehicle stops by a traffic control signal such as an intersection, the internal combustion engine (E / G) 1 mounted on the vehicle stops and the control device 10 starts a timer.
In step S3, it is determined whether or not the timer elapsed time T ≧ T5 is constant (threshold).
In FIG. 3A, the lubricating oil pressure P of each sliding portion 22 decreases from the lubricating oil pressure P1 at time Ta with the passage of time.
A signal from the lubricating oil pressure detection sensor 9 is also input. The signal from the lubricating oil pressure detection sensor 9 determines whether the lubricating oil pressure P ≦ P2 threshold value of each sliding portion 22.
If at least one of the timer elapsed time T information and the lubricating oil pressure P information is Yes, the process proceeds to step S4. Prevention of running out of lubricating oil of each sliding portion 22 is performed on the safety side.
When neither the elapsed time T nor the lubricating oil pressure P satisfies the threshold value which is a condition, No is selected and the process returns to step S2.

In step S4, the control device 10 operates the electric oil pump 6.
Even when the electric oil pump 6 starts operating, it takes time for the lubricating oil to reach each sliding portion 22, so the lubricating oil pressure P continues to decrease.
The electric oil pump 6 starts to operate, and after the time T6 has elapsed, the lubricating oil pressure P of each sliding portion 22 changes from falling to rising.

In step S5, the lubricating oil is pumped by the electric oil pump 6 to each sliding portion 22 which is a lubricating portion. The pumping amount of the lubricating oil is expected to flow out from the gap between the sliding portions 22, The amount of the lubricating oil pressure P is maintained at a constant pressure P3 lower than the lubricating oil pressure P1 when the internal combustion engine 1 is operated.
The operation of the electric oil pump 6 is ON / OFF controlled by the control device 10 and is driven at the rated rotational speed when it is turned ON to discharge a constant pressure P3.
The time to maintain is the time Tc until the internal combustion engine 1 is restarted.
In step S6, when the driver operates the vehicle, the internal combustion engine 1 starts (time Tc). (Internal combustion engine 1 has been stopped for time T0)
Select Yes and go to step S7.
If the internal combustion engine 1 is not started in step S6, the process returns to step S4, and the operation of the electric oil pump 6 is continued.
Holding the lubricating oil pressure P at P3 lower than P1 does not require holding the lubricating oil pressure P3 when the internal combustion engine 1 is operating while the internal combustion engine 1 is stopped.
Therefore, when the internal combustion engine 1 is started, the lubricating oil is held in each sliding portion 22, and the lubricating oil amount required for lubricating each sliding portion 22 may be sufficient. By doing in this way, the electric oil pump 6 can be reduced in size, weight, cost, power consumption can be suppressed, and fuel consumption can be improved.

In step S7, as shown in FIG. 3B, the drive of the electric oil pump 6 is continued by providing a delay time T7 after starting the internal combustion engine 1 to drive the electric oil pump 6.
This is because the lubricating oil discharge pressure of the mechanical oil pump 5 is low at the beginning of the internal combustion engine 1. Therefore, by using both the mechanical oil pump 5 and the electric oil pump 6 in combination, the lubricating oil pressure P of each sliding portion 22 is quickly increased to P1, and the lubricating oil of each sliding portion 22 is insufficient. It is to reduce the time.

In step S8, the electric oil pump 6 is stopped.
When the operation of the internal combustion engine 1 continues and the amount of lubricating oil discharged from the mechanical oil pump 5 increases, the lubricating oil pressure P in the first oil passage 51 rises and the second check valve 8 is connected to the electric oil pump. It comes to press to the 6th side.
Therefore, the electric oil pump 6 is stopped by the control device 10. The process ends in step S10.

In this way, even if the internal combustion engine 1 is stopped, the lubricating oil can be held in each sliding portion 22 by the electric oil pump 6 and the first and second check valves 7 and 8. The wear resistance and cooling effect of the moving part 22 can be maintained, and the durability of the internal combustion engine can be improved.
In addition, since the electric oil pump is operated when the lubricating oil is reduced, the operation time of the electric oil pump is shortened, the durability is improved, and the fuel consumption of the internal combustion engine due to the reduction of power consumption by driving is reduced. Can be planned.
Furthermore, the discharge amount of the electric oil pump 6 is set so as to be a lubricating oil pressure P3 lower than the lubricating oil pressure P1 generated in each sliding portion 22 depending on the discharge amount of the mechanical oil pump 5. The oil pump will be reduced in size and weight to improve fuel efficiency by reducing cost and power consumption.

  The present invention can be applied to a lubricating oil retaining device for an internal combustion engine that retains lubricating oil in a lubricating portion of the internal combustion engine, which is frequently stopped and started, even when the internal combustion engine is stopped.

DESCRIPTION OF SYMBOLS 1 Internal combustion engine 2 Internal combustion engine main body 3 Oil pan 5 Mechanical oil pump 6 Electric oil pump 7 1st check valve 8 2nd check valve 9 Lubricating oil pressure detection sensor 10 Controller 11 Rotation speed sensor 21 Oil gallery 22 Each Sliding part (lubricated part)

Claims (6)

In an internal combustion engine equipped with an idle stop & start device,
A mechanical oil pump that is driven by the internal combustion engine and pumps lubricating oil to a lubricating portion of the internal combustion engine;
A first check valve that is interposed in an intermediate portion of a first oil passage that connects the lubricating portion and the mechanical oil pump, and prevents the lubricating oil from flowing back to the mechanical oil pump side;
An electric oil pump having a second oil passage connected to the downstream side of the first check valve;
A second check valve for preventing the lubricating oil from flowing backward to the electric oil pump side downstream of the electric oil pump in the second oil passage;
A control device for controlling the operation of the electric oil pump,
When the internal combustion engine is stopped and the lubricating oil filled in the lubricating portion is reduced, the control device operates the electric oil pump to pump the lubricating oil to the lubricating portion. A lubricating oil retaining device for an internal combustion engine.   2. The reduction of the lubricating oil is defined as a reduction of the lubricating oil by using at least one of a lubricating oil pressure of the lubricating portion or a time after a predetermined time has elapsed after the internal combustion engine is stopped. A lubricating oil retaining device for an internal combustion engine as described.   3. The discharge amount of the electric oil pump is set to a constant pressure lower than the lubricating oil pressure generated in the lubrication part according to the discharge amount of the mechanical oil pump. 4. A lubricating oil retaining device for an internal combustion engine according to claim 1.   4. The internal combustion engine according to claim 3, wherein the operation of the electric oil pump is ON-OFF controlled by the control device, and is driven at a rated speed when being turned ON to discharge the constant pressure. Lubricating oil retaining device.   5. The lubricating oil retaining device for an internal combustion engine according to claim 1, wherein the control device stops the electric oil pump when the internal combustion engine is started.   6. The lubricating oil retaining device for an internal combustion engine according to claim 5, wherein the control device provides a delay time until the electric oil pump stops after the internal combustion engine is started.

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