JP5821676B2 - Control device for internal combustion engine - Google Patents

Description

  The present invention relates to a control device for an internal combustion engine, and more particularly to a control device for an internal combustion engine that includes a lubricating oil supply device that lubricates a high-pressure fuel pump that supplies high-pressure fuel to a fuel reservoir.

  In an internal combustion engine that requires high pressure for fuel supplied to the injector, such as a direct injection type internal combustion engine mounted on a vehicle, the fuel sent from the fuel tank is pressurized with a high-pressure fuel pump. The fuel is pumped to the fuel reservoir, and the fuel pumped to the fuel reservoir is injected from the injector into the combustion chamber.

  This type of high-pressure fuel pump includes a cylinder having a pressure chamber to which fuel pressurized to a feed pressure is supplied from a feed pump, a plunger that is reciprocally inserted into the cylinder, and a plunger that is connected to the plunger. A lifter that reciprocates, a lifter guide that reciprocally accommodates the lifter and guides the reciprocation of the lifter, a drive cam that reciprocates the lifter, and a cylinder and the lifter are disposed between the lifter and the lifter It is possible to boost the fuel pressure supplied to the pressure chamber above the feed pressure and feed it to the fuel reservoir by converting the rotational movement of the drive cam into the reciprocating movement of the lifter and plunger. It has become.

In this high pressure fuel pump, when the pressure chamber becomes high pressure, the reaction force applied from the pressure chamber to the plunger increases, so the contact pressure between the plunger and the cylinder and the contact pressure between the lifter and the lifter guide during the reciprocating movement of the plunger. It gets bigger.
For this reason, seizing tends to occur at the contact portion between the plunger and the cylinder or the contact portion between the lifter and the lifter guide. Therefore, it is necessary to prevent seizure of the contact portion between the plunger and the cylinder and the contact portion between the lifter and the lifter guide.

  As a device for preventing seizure of the contact portion between the plunger and the cylinder and the contact portion between the lifter and the lifter guide, there is a lubrication device that supplies lubricating oil stored in an oil pan toward the lifter of the high-pressure fuel pump. Known (see, for example, Patent Documents 1 and 2).

  In this lubricating device, the lubricating oil supplied toward the lifter of the high-pressure fuel pump can be supplied to the contact part between the plunger and the cylinder and the contact part between the lifter and the lifter guide. An oil film can be formed at the contact sites to prevent seizure from occurring at these contact sites.

JP 2008-19842 A JP 2010-150965 A

However, in such a conventional lubricating device, when the lubricating oil stored in the oil pan is insufficient, the lubricating oil level (oil level height) stored in the oil pan decreases with respect to the appropriate amount. As a result, the strainer for sucking the lubricating oil from the oil pan toward the oil pump sucks air (hereinafter, this state is referred to as air sucking).
When the oil pump is in the air sucking state, the amount of lubricating oil discharged from the oil pump is reduced, so that a sufficient amount of lubricating oil cannot be supplied from the oil pump to the lifter.

  In particular, when the pressurizing chamber of the high pressure fuel pump becomes high pressure, the reaction force applied to the plunger from the pressurizing chamber increases as described above, so the contact portion between the plunger and the cylinder and the contact portion between the lifter and the lifter guide Baking is more likely to occur.

  The present invention has been made to solve the above-described conventional problems. When the lubricating oil stored in the lubricating oil storage means is insufficient, the contact portion between the plunger and the cylinder, the lifter and the lifter guide, An object of the present invention is to provide a control device for an internal combustion engine that can suppress the occurrence of seizure at the contact portion.

  In order to achieve the above object, a control apparatus for an internal combustion engine according to the present invention includes (1) a cylinder having a pressure chamber to which fuel pressurized to a feed pressure is supplied from a feed pump, and reciprocating within the cylinder. A plunger inserted into the plunger, a lifter connected to the plunger and reciprocatingly moving the plunger, a lifter guide that houses the lifter and guides the reciprocating movement of the lifter, and a drive cam that reciprocally moves the lifter; A biasing member that is disposed between the cylinder and the lifter and biases the lifter toward the drive cam, and converts the rotational motion of the drive cam into the reciprocating motion of the lifter and the plunger; A high-pressure fuel pump capable of boosting the fuel pressure in the pressure chamber above the feed pressure and pumping the fuel pressure to the fuel reservoir, and a lubricating oil reservoir A control device for an internal combustion engine including a lubricating oil supply device that supplies the retained lubricating oil to the high-pressure fuel pump by an oil pump, wherein the discharge pressure of the lubricating oil discharged from the oil pump is abnormal On the condition that the fuel pressure in the pressurizing chamber is detected, the fuel pressure in the pressurizing chamber is reduced to the feed pressure.

  This internal combustion engine control apparatus reduces the fuel pressure in the pressurizing chamber to the feed pressure on condition that the pump control means detects an abnormality in the discharge pressure of the lubricating oil discharged from the oil pump. When the lubricating oil stored in the lubricating oil storage means is insufficient and the amount of lubricating oil supplied to the high-pressure fuel pump decreases, the pressure in the pressurizing chamber can be lowered.

  For this reason, the reaction force applied to the plunger from the pressurizing chamber when the plunger moves can be reduced, and the contact pressure at the contact portion between the plunger and the cylinder and the contact portion between the lifter and the lifter guide can be reduced. As a result, it is possible to suppress the occurrence of seizing at the contact portion between the plunger and the cylinder and the contact portion between the lifter and the lifter guide.

  (1) In the control device for an internal combustion engine according to (1), (2) the high-pressure fuel pump has an on-off valve that opens and closes a low-pressure fuel passage portion that communicates the pressurizing chamber and the feed pump, and the pump control means Adjusts the fuel pressure supplied from the pressurizing chamber to the fuel reservoir by controlling the valve closing period in the process of pressurizing the pressurizing chamber with the plunger, On the condition that an abnormality in the discharge pressure is detected, the on-off valve is controlled to be fully opened to reduce the fuel pressure in the pressurizing chamber to the feed pressure.

  In this internal combustion engine control device, on the condition that the pump control means detects an abnormality in the discharge pressure of the oil pump, the on-off valve is controlled to be fully opened to reduce the fuel pressure in the pressurizing chamber to the feed pressure. Therefore, the pressurizing chamber can be reliably reduced to the feed pressure, and the reaction force applied to the plunger from the pressurizing chamber when the plunger moves can be reduced.

  (1) In the control device for an internal combustion engine of (2), (3) warning means for giving a warning based on an abnormal signal output from the pump control means, and the pump control means includes the oil pump On the condition that the abnormality of the discharge pressure of the lubricating oil discharged from is detected, the abnormality signal is output to the warning means.

  In this internal combustion period control device, on the condition that the pump control means detects an abnormality in the discharge pressure of the lubricating oil discharged from the oil pump, an abnormality signal is output to the warning means and a warning is given by the warning means. The driver can be warned that the lubricating oil stored in the lubricating oil storage means is insufficient. For this reason, it is possible to prompt the driver to check the lubricating oil in the oil storing means or to replenish the oil storing means with lubricating oil.

  In the control device for an internal combustion engine according to the above (1) to (3), (4) the pump control means is configured such that the lubricating oil stored in the lubricating oil storage means is supplied to the high-pressure fuel pump by the oil pump. A period until the oil is collected by the lubricating oil storage means is set as a lubricating oil circulation period, and the pressure value of the discharge pressure of the lubricating oil discharged from the oil pump is predetermined within the lubricating oil circulation period that is temporally continuous. The time when the value is less than or equal to the value is integrated, and the fact that the integrated value is equal to or greater than the determination value is used as an abnormality detection condition for the discharge pressure of the lubricating oil.

  This internal combustion engine control device determines that the accumulated value of the time during which the pressure value of the oil discharge pressure has become equal to or less than a predetermined value within the lubricating oil circulation period is equal to or greater than a determination value, Therefore, when the fluctuation cycle of the oil discharge pressure becomes long, it is possible to detect that the oil pump is in the air sucking state and the lubricating oil storing means is short of lubricating oil.

  According to the present invention, when the lubricating oil stored in the lubricating oil storage means is insufficient, it is possible to suppress the occurrence of seizure at the contact portion between the plunger and the cylinder and the contact portion between the lifter and the lifter guide. A control device for an internal combustion engine can be provided.

1 is a diagram illustrating an embodiment of a control device for an internal combustion engine according to the present invention, and is a schematic configuration diagram of a fuel supply system, a lubricating oil supply device, and a control device provided in the internal combustion engine. 1 is a diagram showing an embodiment of a control device for an internal combustion engine according to the present invention, and is a cross-sectional view of a high-pressure fuel pump. It is a figure which shows one Embodiment of the control apparatus of the internal combustion engine which concerns on this invention, and is a figure which shows a fuel pressure map. 1 is a diagram showing an embodiment of a control apparatus for an internal combustion engine according to the present invention, and the relationship between oil discharge pressure and time for each oil level of an oil pan under conditions of a constant engine speed and a constant oil temperature. FIG. It is a figure which shows one Embodiment of the control apparatus of the internal combustion engine which concerns on this invention, and is a flowchart of a pump protection control process. 6 is a diagram showing an embodiment of a control device for an internal combustion engine according to the present invention, and is a flowchart of pump protection control processing subsequent to FIG. 5. FIG.

Embodiments of an internal combustion engine control apparatus according to the present invention will be described below with reference to the drawings.
FIGS. 1-6 is a figure which shows one Embodiment of the control apparatus of the internal combustion engine which concerns on this invention.
First, the configuration will be described.
The control device of the present invention is applied to, for example, an in-cylinder direct injection engine (internal combustion engine) including a fuel supply system and a lubricating oil supply device.

  In FIG. 1, a fuel supply system includes a fuel tank 1, a feed pump 2, a pressure regulator 3, a high pressure fuel pump 4, a delivery pipe 5 as a fuel reservoir, a fuel injection valve 6, a low pressure fuel pipe 7, a high pressure fuel pipe 8, The return pipe 9 and the like are included.

  The feed pump 2 pressurizes the fuel from the fuel tank 1 to a feed pressure and sends it out. The pressure regulator 3 returns the fuel in the low-pressure fuel pipe 7 to the fuel tank 1 when the fuel pressure in the low-pressure fuel pipe 7 serving as the low-pressure fuel passage portion exceeds a predetermined pressure. Maintain fuel pressure at feed pressure.

  The high-pressure fuel pump 4 is pressurized to the feed pressure by the feed pump 2 and sent out. The fuel filtered by the filter 10 is boosted and stored in the delivery pipe 5. The configuration of the high-pressure fuel pump 4 will be described later.

  The delivery pipe 5 supplies high-pressure fuel stored therein to the fuel injection valve 6. The fuel injection valve 6 directly supplies the high-pressure fuel in the delivery pipe 5 to each combustion chamber of the engine (not shown). To be injected. The number of fuel injection valves 6 is the same as the number of cylinders of the engine. For example, as shown in the figure, when four fuel injection valves 6 are used, for example, a four-cylinder engine is used.

  A return pipe 9 is connected to the delivery pipe 5 via a relief valve 11. The relief valve 11 is opened when the fuel pressure in the delivery pipe 5 exceeds a predetermined pressure, and a part of the fuel stored in the delivery pipe 5 is returned to the fuel tank 1 through the return pipe 9. The fuel pressure in the delivery pipe 5 is prevented from excessively rising.

  The low pressure fuel pipe 7 is provided with a pulsation damper 12. The pulsation damper 12 suppresses pulsation of fuel pressure in the low-pressure fuel pipe 7 when the high-pressure fuel pump 4 is operated. Hereinafter, the fuel pressure is referred to as fuel pressure.

  In FIG. 2, the high-pressure fuel pump 4 is of a plunger type and includes a pump unit 20, an electromagnetic spill valve 30, a check valve 40, and a roller lifter 50. The pump unit 20 includes a cylinder 21, a pressurizing chamber 22, and a plunger 23.

  The cylinder 21 is provided with a guide hole 21a of the plunger 23 in the vertical direction, and the plunger 23 can reciprocate in the vertical direction in the cylinder 21 along the guide hole 21a.

  The pressurizing chamber 22 is provided in the upper part of the cylinder 21 so as to be positioned on the upper end side of the guide hole 21a, and is communicated with the feed pump 2 through the low-pressure fuel pipe 7 as shown in FIG. The communication pipe 5 communicates with the delivery pipe 5 through the high-pressure fuel pipe 8. The plunger 23 is formed of a substantially cylindrical member, and is inserted into the guide hole 21a of the cylinder 21 so as to be slidable up and down.

  As an operation of the pump unit 20, the plunger 23 is reciprocated in the vertical direction in the cylinder 21 by the rotating drive cam 18, and the volume of the pressurizing chamber 22 is expanded or reduced.

  The fuel leaking from the fitting gap between the plunger 23 and the guide hole 21a is accumulated in the fuel storage chamber 26 at the upper part of the seal unit 25. This fuel is returned to the return pipe 9 via the fuel discharge pipe 13. It is designed to be discharged (see FIG. 1).

  The electromagnetic spill valve 30 as an on-off valve is provided above the pump unit 20 and controls communication between the low-pressure fuel pipe 7 and the pressurizing chamber 22 by controlling energization to the electromagnetic solenoid 31. is there.

  The electromagnetic spill valve 30 includes an electromagnetic solenoid 31, a bobbin 32, a core 33, an armature 34, a poppet valve 35, a seat body 36, and a compression coil spring 37.

  As an operation of the electromagnetic solenoid 31, when energization to the electromagnetic solenoid 31 is stopped, the poppet valve 35 opens the through hole of the seat body 36 by the extension restoring force of the compression coil spring 37, and the low pressure fuel pipe 7 and the pressurizing chamber 22 are communicated (valve open state).

  On the other hand, when the electromagnetic solenoid 31 is energized, the armature 34 moves toward the core 33 so as to compress the compression coil spring 37, so that the poppet valve 35 closes the through hole of the seat body 36, and the low-pressure fuel pipe 7 The pressurizing chamber 22 is shut off (closed state).

  The check valve 40 prevents the fuel discharged from the high-pressure fuel pump 4 from flowing backward, and includes a valve body 41, a seat body 42, a valve body 43, and a compression coil spring 44.

  The check valve 40 allows the fuel pressure-fed from the pressurizing chamber 22 through the high-pressure fuel passage 21b formed in the cylinder 21 to be supplied to the delivery pipe 5 via the high-pressure fuel pipe 8, and the delivery pipe The reverse flow from 5 to the pressurizing chamber 22 is prohibited.

The roller lifter 50 converts the rotational motion of the drive cam 18 into a linear motion and transmits it to the plunger 23 to slide the plunger 23 in the vertical direction with respect to the cylinder 21. And a roller 53.
The lifter 51 is accommodated in the guide hole 56a of the lifter guide 56, and is accommodated in the guide hole 56a so as to reciprocate along the central axis of the lifter 51.

  The lifter guide 56 is attached to a pump attachment portion 57 such as a cylinder head cover provided on a cylinder head that supports the intake camshaft (or exhaust camshaft) 14, for example. The intake camshaft 14 is provided in the cylinder head, and the cylinder head cover is attached to the upper part of the cylinder head as is well known.

  The lifter 51 is formed in a substantially cylindrical shape, and is provided with a partition wall 51a that bisects vertically in the middle of the lifter 51. The upper peripheral wall 51b is above the partition wall 51a, and the lower peripheral wall is on the lower side. 51c.

  The lower end of the plunger 23 is in contact with the upper surface of the partition wall 51 a of the lifter 51 via the retainer 27. That is, the lifter 51 is connected to the plunger 23. A roller 53 is rotatably supported on the lower peripheral wall 51 c of the lifter 51 via a support shaft 52.

  The roller 53 is rotatably supported on the outer diameter side of the support shaft 52 via a plurality of rollers 54, and the drive cam 18 is brought into contact with the outer peripheral surface of the roller 53. . In order to press the roller 53 against the drive cam 18, a compression coil spring 55 as an urging member is interposed between the partition wall 51 a of the lifter 51 and the cylinder 21 in a compressed state.

  In other words, the compression coil spring 55 presses the roller 53 against the drive cam 18 by urging the lifter 51 toward the drive cam 18 by the extension restoring force of the compression coil spring 55.

  For this reason, the poppet valve 35 closes the through hole of the seat body 36, the low-pressure fuel pipe 7 and the pressurizing chamber 22 are shut off, and the valve closing period of the poppet valve 35 during the compression stroke of the plunger 23 is increased or decreased. Thus, the fuel pressure in the pressurizing chamber 22 can be changed. Therefore, the longer the valve closing timing of the poppet valve 35, the higher the fuel pressure in the pressurizing chamber 22 can be set to a higher pressure than the feed pressure.

  As shown in FIG. 1, the electromagnetic spill valve 30 controls the energization of the electromagnetic solenoid 31 based on a signal from an engine ECU (Electronic Control Unit) 71 so that the poppet valve 35 opens the through hole of the seat body 36. The low-pressure fuel pipe 7 and the pressurizing chamber 22 are controlled to be opened or closed by being closed. That is, the engine ECU 71 controls the closing period of the poppet valve 35 by controlling the energization time of the electromagnetic solenoid 31.

  Specifically, the CPU of the engine ECU 71 controls the energization time of the electromagnetic solenoid 31 based on the fuel pressure map set based on the engine load and the engine speed shown in FIG. Control the valve closing period. By controlling the energization time of the electromagnetic solenoid 31 in this way, the fuel pressure supplied from the high-pressure fuel pump 4 to the delivery pipe 5 is adjusted.

  In the high-pressure fuel pump 4 configured as described above, when the cam nose 18a of the drive cam 18 pushes up the roller 53 of the roller lifter 50 due to the rotation of the drive cam 18 accompanying the engine operation, the plunger 23 of the pump unit 20 rises. Thus, the compression coil spring 55 is compressed and the volume of the pressurizing chamber 22 is reduced.

  On the other hand, when the cam nose 18a moves away from the roller 53 of the roller lifter 50 and the base circle of the drive cam 18 contacts, the roller lifter 50 and the plunger 23 are lowered by the expansion restoring force of the compression coil spring 55, and the volume of the pressurizing chamber 22 is increased. Enlarged.

  First, during the period in which the contact position between the drive cam 18 and the roller 53 is shifted from the apex of the cam nose 18a of the drive cam 18 to the base circle, the volume of the pressure chamber 22 is increased by lowering the plunger 23. become.

  For this reason, in the process in which the plunger 23 is lowered, by stopping energization of the electromagnetic spill valve 30 to the electromagnetic solenoid 31, the electromagnetic spill valve 30 is opened by the expansion restoring force of the compression coil spring 37, and the poppet valve 35 is opened. When the low-pressure fuel pipe 7 and the pressurizing chamber 22 communicate with each other, the fuel sent from the feed pump 2 is sucked into the pressurizing chamber 22 through the low-pressure fuel pipe 7 (intake stroke).

  On the other hand, the volume of the pressure chamber 22 is reduced by raising the plunger 23 during a period in which the contact position between the drive cam 18 and the roller 53 is shifted from the base circle of the drive cam 18 to the apex of the cam nose 18a. Become.

  Therefore, in the process of raising the plunger 23, the electromagnetic spill valve 30 is closed against the elastic force of the compression coil spring 37 by energizing the electromagnetic solenoid 31, and the low-pressure fuel pipe 7 is closed. When the pressure chamber 22 is shut off, the fuel in the pressure chamber 22 is pressurized, and high-pressure fuel is discharged toward the delivery pipe 5 through the high-pressure fuel pipe 8 (pressure increase stroke).

  On the other hand, as shown in FIG. 1, the engine is provided with an oil supply device 61 as a lubricating oil supply device.

  The oil supply device 61 includes an oil pan 62 as a lubricating oil storage means, an oil strainer 63, an oil pump 64 driven by the power of the crankshaft, an oil passage portion 65 such as a main oil gallery, and an oil passage portion. And an injection nozzle 66 that receives oil supplied from 65 and injects the oil.

  The oil pan 62 is provided at the bottom of the cylinder block that houses the crankshaft and piston, and the oil pan 62 stores oil Oi as lubricating oil.

The oil strainer 63 is immersed in the oil pan 62 and filters the oil Oi stored in the oil pan 62.
The oil Oi stored in the oil pan 62 is sucked up by the oil pump 64 and discharged to the oil passage portion 65.

  The oil pump 64 is composed of, for example, a trochoid pump, a gear pump, and the like, and is connected to the crankshaft via a chain so that the oil pump 64 is driven at a constant speed with the crankshaft by transmitting power from the crankshaft. It has become.

  The oil passage portion 65 is constituted by a main gallery provided in the cylinder block, and supplies the oil discharged from the oil pump 64 to the injection nozzle 66.

  The injection nozzle 66 is configured to inject oil Oi toward the lifter 51 and is attached to a cylinder head attached to the upper part of the cylinder block so as to be positioned in the vicinity of the intake camshaft 14.

The oil Oi injected to the lifter 51 is supplied between the cylinder 21 and the plunger 23 through the gap between the lifter 51 and the lifter guide 56.
For this reason, an oil film is formed in the sliding part of the lifter 51 and the lifter guide 56 and the sliding part of the cylinder 21 and the plunger 23, and lubrication of these sliding parts is performed.

Further, the contact portion between the drive cam 18 and the roller 53 is lubricated by the oil Oi sprayed from the spray nozzle 66 toward the lifter 51.
The oil Oi supplied from the injection nozzle 66 to the high pressure fuel pump 4 drops inside the cylinder head and the cylinder block and returns to the oil pan 62 again.

  That is, the oil Oi in the oil pan 62 is repeatedly sucked up by the oil pump 64 from the oil pan 62 and supplied to the high-pressure fuel pump 4 and then recovered in the oil pan 62.

  As shown in FIG. 1, the engine control device 70 includes an engine ECU 71, an oil temperature sensor 72, a hydraulic pressure sensor 73, an engine speed sensor 74, and a warning lamp 75.

  The oil temperature sensor 72 and the hydraulic pressure sensor 73 are provided in the oil passage portion 65, respectively. The oil temperature sensor 72 is constituted by, for example, a thermistor whose resistance value changes according to temperature, and outputs a voltage that changes according to the change of resistance value to the engine ECU 71 as oil temperature information. .

The oil pressure sensor 73 detects the oil pressure of the oil flowing through the oil passage portion 65 and outputs a signal corresponding to the oil pressure to the engine ECU 71 as oil pressure information.
The engine speed sensor 74 is constituted by a crank position sensor, for example. The engine speed sensor 74 detects the engine speed (rpm) based on the rotation angle of the crankshaft, and detects the detected engine speed. A signal corresponding to (rpm) is output to the engine ECU 71.

  The engine ECU 71 includes a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), an input interface, an output interface, and the like.

The ROM of the engine ECU 71 stores various control programs including a pump protection control program, a map referred to when executing these various control programs, and the like.
Further, the ROM stores an oil circulation period determination map, a fuel pressure map shown in FIG. 3 and the like as a control map.

  In the oil circulation period determination map, the period from when the oil Oi stored in the oil pan 62 is supplied to the high-pressure fuel pump 4 by the oil pump 64 until it is collected by the oil pan 62 is set as the oil circulation period. This oil circulation period is stored in association with a plurality of oil temperatures. That is, the oil circulation period has a different length for each of a plurality of oil temperatures.

  The oil circulation period is stored in the ROM in advance as a result of an experiment. When the oil temperature is low, the oil circulation period is set long because the oil temperature has a high viscosity. Is high, the oil circulation period is set short because the viscosity of the oil temperature is low.

  In the oil circulation period determination map, determination values corresponding to the respective oil circulation periods are stored. This determination value is set to a certain ratio of length (time) corresponding to the length of the oil circulation period within the range of the length of the oil circulation period. That is, the determination value is set longer when the oil circulation period is longer than when the oil circulation period is short.

The engine ECU 71 executes pump protection control based on detection information from the oil temperature sensor 72, the hydraulic pressure sensor 73, and the engine speed sensor 74.
That is, the engine ECU 71 reads out the oil circulation period and the determination value corresponding to the oil temperature of the oil from the oil circulation determination map based on the detection information from the oil temperature sensor 72. The engine ECU 71 continues the oil circulation period in time during the operation of the engine, acquires the oil pressure value discharged from the oil pump 64 based on the detection information from the oil pressure sensor 73, and oils within each oil circulation period. The time when the hydraulic pressure value of the pump 64 is equal to or less than the predetermined value is integrated, and the integrated value is stored in the integrating counter of the RAM.

  Then, the engine ECU 71 determines that an abnormality in the hydraulic pressure has occurred on the condition that the integrated value of the time when the hydraulic pressure value has become equal to or less than the predetermined value in each oil circulation period has become equal to or greater than the determination value. An abnormal signal is transmitted to the warning lamp 75.

  Further, the engine ECU 71 includes a timer, and the engine ECU 71 measures the time when the oil circulation period and the pressure value are equal to or less than a predetermined value by the timer.

  The warning lamp 75 is connected to the engine ECU 71. The warning lamp 75 indicates that the oil level in the oil pan 62 has decreased due to an abnormality in the hydraulic pressure discharged from the oil pump 64, that is, an oil shortage has occurred. It is a warning light that warns that it has been done.

  The warning lamp 75 is lit or blinked when an abnormality signal is input from the engine ECU 71 to warn of an abnormality in hydraulic pressure, thereby warning the driver that the oil level in the oil pan 62 has decreased. In the present embodiment, the warning lamp 75 constitutes a warning means.

  Further, the engine ECU 71 stops energization of the electromagnetic solenoid 31 on condition that a hydraulic pressure abnormality has occurred. When the energization of the electromagnetic solenoid 31 is stopped, the poppet valve 35 opens the through hole of the seat body 36 by the expansion restoring force of the compression coil spring 37 and opens the low pressure fuel pipe 7 and the pressurizing chamber 22 in communication. The valve state is reached, and the fuel pressure in the pressurizing chamber 22 decreases to the feed pressure. In the present embodiment, the engine ECU 71 constitutes a pump control means.

Next, a pump protection control process executed by the engine ECU 71 will be described with reference to FIGS.
FIG. 4 is a diagram showing the relationship between the oil pressure and the time for each oil level of the oil pan 62 under the conditions of a constant engine speed and a constant oil temperature.
As shown in FIG. 4, when the oil level L0 of the oil pan 62 is appropriate, as shown by the hydraulic pressure characteristic A, the fluctuation of the hydraulic pressure is small and the characteristic is flat.

  Further, when the oil level is lowered from the proper oil level L0 to the oil level L1, the oil pump 64 bites bubbles contained in the air sucked by the oil strainer 63, so-called air biting occurs, and pressure fluctuation occurs. Resulting in. At this time, as shown by the hydraulic pressure characteristic B, the fluctuation of the hydraulic pressure becomes large, and the hydraulic pressure changes in a short cycle.

  Further, when the oil level of the oil pan 62 decreases from the oil level L1 to the oil level L2, more air is sucked by the oil pump 64, and the fluctuation of the oil pressure becomes larger as shown by the hydraulic pressure characteristic C. The characteristic varies with a long period.

  Here, as shown in FIG. 4, the oil circulation period CT is temporally continuous, and when the oil circulation period CT located in the center of FIG. 4 is viewed, the oil level of the oil pan 62 is the oil level. When it is at L2, the fluctuation cycle of the hydraulic pressure becomes longer until the oil circulation period CT.

  For this reason, the engine ECU 71 of the present embodiment integrates the time (for example, indicated by Tk in FIG. 4) when the hydraulic pressure value becomes equal to or less than a predetermined value within each temporally continuous oil circulation period CT. It is determined that the oil level in the oil pan 62 has decreased on the condition that the value is equal to or greater than the determination value.

  When the engine ECU 71 determines that the oil level in the oil pan 62 has decreased, the engine ECU 71 reduces the pressure in the pressurizing chamber 22 to the feed pressure and outputs an abnormal signal to the warning lamp 75. 75 is used to give a warning.

  In the present embodiment, the time when the hydraulic pressure value is equal to or less than a predetermined value is integrated within each oil circulation period CT that is temporally continuous, and the oil pan 62 is provided on condition that the integrated value becomes equal to or greater than the determination value. The reason why it is judged that the oil level has decreased is as follows.

  When the oil pressure fluctuation of the oil discharged from the oil pump 64 to the oil passage portion 65 is repeated a predetermined number of times within a predetermined time, that is, when it is determined that the oil level of the oil pan 62 has decreased based on the oil pressure fluctuation frequency. Cannot accurately determine whether the hydraulic pressure is normal or abnormal when the pressure fluctuation period within a certain time is long.

For example, when the pressure fluctuation period extends to the oil circulation period from when the oil Oi stored in the oil pan 62 is supplied to the high-pressure fuel pump 4 by the oil pump 64 until it is recovered by the oil pan 62, the hydraulic pressure The fluctuation occurs only once within a certain time.
For this reason, when the pressure fluctuation period is long, it is determined that the oil pressure is normal, and it is impossible to accurately determine that the oil level has decreased.

  Therefore, in the present embodiment, the oil passage portion 65 is provided on the condition that the integrated value of the time when the hydraulic pressure value becomes equal to or less than the predetermined value within each oil circulation period CT that is temporally continuous becomes equal to or greater than the determination value. It is determined that the oil pressure in the oil pan becomes abnormal and the oil pressure in the oil pan 62 has decreased.

  In addition, as shown in FIG. 4, in order to detect oil discharge fluctuations such that the proper oil level L0 or the oil levels L1 and L2 at which the oil level is reduced is detected, the engine speed and the oil temperature are constant. It is desirable that

  Since the oil pressure (discharge amount) of the oil pump 64 changes according to the engine speed, when the change in the engine speed per unit time is large, such as during acceleration / deceleration of the vehicle, the oil pressure changes. growing.

  For this reason, the engine ECU 71 performs a process of adding up the count values in order to prevent erroneous determination that the hydraulic pressure has decreased even though the hydraulic pressure is normal when the fluctuation of the engine speed is large. Do not execute.

  Hereinafter, the pump protection control process will be described with reference to FIGS. 5 and 6 are flowcharts of a pump protection control process executed by the engine ECU 71. The CPU of the engine ECU 71 executes a pump protection control program stored in the ROM. The time interval at which the same steps in this flowchart are executed is constant.

In FIG. 5, when the engine is started, the CPU of the engine ECU 71 resets the accumulation counter in the RAM (step S1).
Next, the CPU of the engine ECU 71 stores the oil temperature To input from the oil temperature sensor 72 in the RAM, and determines whether or not the oil temperature To exceeds the oil temperature Ti (step S2). The oil temperature Ti is set to a low oil temperature at the cold start.

  When the CPU of the engine ECU 71 determines that the oil temperature To is equal to or lower than the oil temperature Ti, the CPU returns to step S1 and does not execute the process of integrating the count values. In other words, the CPU of the engine ECU 71 does not make a hydraulic pressure abnormality determination.

  Further, when the CPU of the engine ECU 71 determines that the oil temperature To exceeds the oil temperature Ti, the oil circulation period determination stored in the ROM based on the oil temperature To input from the oil temperature sensor 72 is performed. With reference to the map, the oil circulation period CT and the judgment value JT associated with the oil temperature To are read and set in the storage area of the RAM (step S3).

  Next, the CPU of the engine ECU 71 reads the engine speed N based on the detection information of the engine speed sensor 74 and sets the engine speed N as an initial engine speed Ne0 in the storage area of the RAM ( In step S4), the oil pressure P0 is read based on the detection information of the oil pressure sensor 73, and the oil pressure P0 is set as an initial value in the storage area of the RAM (step S5).

  Next, the CPU of the engine ECU 71 reads the engine speed N based on the detection information of the engine speed sensor 74 (step S6), and sets this engine speed N as the latest engine speed Ne1 in the storage area of the RAM. It is determined whether or not the difference Ne between the engine speed Ne0 and the engine speed Ne1, that is, the engine speed difference Ne per unit time is, for example, 50 rpm or more (step S7). In addition, this rotation speed difference 50rpm is an illustration, Comprising: It is not limited to this.

  If the CPU of the engine ECU 71 determines that the difference Ne between the engine speed Ne0 and the engine speed Ne1 is 50 rpm or more, the engine speed increases and the vehicle accelerates, or the engine speed It is determined that the number has decreased and the vehicle has decelerated, and the process proceeds to step S1 to reset the RAM integration counter.

  That is, since the oil pump 64 is driven by the engine, the hydraulic pressure increases as the engine speed increases, and the hydraulic pressure decreases as the engine speed decreases, resulting in a large pressure fluctuation of the hydraulic pressure. In addition, the pressure fluctuation time in the oil circulation period CT may be long. For this reason, the CPU of the engine ECU 71 may erroneously determine that the oil level has decreased even though the hydraulic pressure is normal.

  Therefore, when the rotational speed difference Ne between the engine rotational speed Ne0 and the engine rotational speed Ne1 is large, the process of integrating the count values is not executed. That is, the CPU of the engine ECU 71 does not make an oil level abnormality determination.

  When the CPU of the engine ECU 71 determines that the difference Ne between the engine speed Ne0 and the engine speed Ne1 is less than 50 rpm, the CPU 71 determines the latest hydraulic pressure P1 based on the detection information from the oil temperature sensor 72. Read (step S8).

  Next, the CPU of the engine ECU 71 compares the hydraulic pressure P0 set in the RAM with the latest hydraulic pressure P1. If the hydraulic pressure P1 is larger than the hydraulic pressure P0, the CPU 31 sets the hydraulic pressure P1 to the maximum in the oil circulation period CT. The hydraulic pressure P0 is set in the RAM storage area, and a predetermined hydraulic pressure value Ps is calculated based on the maximum hydraulic pressure P0 (step S9).

  The predetermined value Ps is calculated by subtracting a constant pressure value Pi from the maximum hydraulic pressure P0 within the oil circulation period CT, and is set to 20 kPa, for example. That is, the predetermined value Ps = P0−Pi is obtained.

This pressure value Pi is merely an example, and the pressure value Pi differs depending on the type of engine and the operating conditions of the vehicle, and may be varied depending on the engine speed and hydraulic pressure.
In the present embodiment, when the maximum hydraulic pressure P0 is, for example, 70 kPa, the predetermined value Ps is set to 50 kPa.

  Next, the CPU of the engine ECU 71 determines whether or not the difference between P0 and P1 is equal to or less than the pressure value Pi (Step S10). Pi is smaller than P0 and the difference between P0 and P1 exceeds Pi. If it is determined that the hydraulic pressure value has fallen below the predetermined value Ps within the oil circulation period CT, the time when the hydraulic pressure value has fallen below the predetermined value Ps is added to the RAM integration counter (step S11). .

  When the CPU of the engine ECU 71 determines that the difference between P0 and P1 is equal to or less than the pressure value Pi, the oil pressure value exceeds the predetermined value Ps within the oil circulation period CT, and the oil pressure fluctuation is small. If it is determined, the process proceeds to step S6.

  Next, the CPU of the engine ECU 71 adds the integrated value to the RAM integrated counter in step S11, and then whether or not the integrated value of the RAM integrated counter is equal to or greater than the determination value JT set in the RAM storage area in step S3. Is determined (step S12).

  When the CPU of the engine ECU 71 determines that the integrated value of the integrated counter is less than the determination value JT, the time measured by the timer from the current start time of the oil circulation period CT based on the timer is determined in step S3. It is determined whether or not the oil circulation period CT is set in the storage area of the RAM (step S13).

  Here, since the oil viscosity varies depending on the oil temperature, the oil circulation period CT is set to have a different length depending on the oil temperature. Further, the determination value JT is set to a constant time according to the oil circulation period CT.

  If the CPU of the engine ECU 71 determines in step S13 that the measurement time is not longer than the oil circulation period CT, the CPU moves to step S6. If the CPU determines that the measurement time is longer than the oil circulation period CT, It is determined that the pressure is normal, and the process proceeds to step S14.

  In step S14, the CPU of the engine ECU 71 determines the fuel pressure based on the fuel pressure map (see FIG. 3) stored in the ROM, and then controls the energization time of the electromagnetic solenoid 31 to control the closing period of the poppet valve 35. By doing so (step S15), the pressure of the fuel in the pressurizing chamber 22 is increased, and high-pressure fuel having a pressure corresponding to the fuel pressure map is supplied to the delivery pipe 5.

  The CPU of the engine ECU 71 includes, as engine load shown in the fuel pressure map of FIG. 4, detection information from the water temperature sensor 72, detection information from an air flow meter (not shown) that detects an intake air amount in an intake pipe (not shown), and an accelerator pedal The engine load can be estimated based on detection information from an accelerator opening sensor or the like that detects the opening of the engine. Next, the CPU of the engine ECU 71 moves the process to step S1.

  If the CPU of the engine ECU 71 determines in step S12 that the integrated value of the RAM integrated counter is equal to or greater than the determination value JT set in the storage area of the RAM in step S3, a hydraulic pressure abnormality has occurred. Then, it is determined that the oil level in the oil pan 62 has decreased, an abnormal signal is output to the warning lamp 75 (step S16), and the warning lamp 75 is lit or blinked.

  Next, the CPU of the engine ECU 71 stops energization of the electromagnetic solenoid 31 (step S17) and ends the current process. When the energization of the electromagnetic solenoid 31 is stopped, the poppet valve 35 opens the through hole of the seat body 36 by the expansion restoring force of the compression coil spring 37 and opens the low pressure fuel pipe 7 and the pressurizing chamber 22 in communication. The valve state is reached, and the fuel pressure in the pressurizing chamber 22 decreases to the feed pressure.

  As described above, the control device 70 according to the present embodiment controls the poppet valve 35 to be fully opened and controls the high pressure fuel pump on condition that the engine ECU 71 detects an abnormality in the discharge pressure of the oil discharged from the oil pump 64. 4, the fuel pressure in the pressurizing chamber 22 is reduced to the feed pressure, so that when the oil in the oil pan 62 is insufficient and the amount of oil supplied to the high-pressure fuel pump 4 is reduced, the pressure is increased. The pressure in the chamber 22 can be reliably reduced.

  For this reason, the reaction force applied to the plunger 23 from the pressurizing chamber 22 when the plunger 23 is raised can be reduced, and the contact pressure of the contact portion between the plunger 23 and the cylinder 21 and the contact portion between the lifter 51 and the lifter guide 56 can be reduced. Can be lowered. As a result, it is possible to suppress the occurrence of seizing at the contact portion between the plunger 23 and the cylinder 21 and the contact portion between the lifter 51 and the lifter guide 56.

  Further, the control device 70 of the present embodiment has a warning lamp 75 that gives a warning based on an abnormality signal output from the engine ECU 71, and the engine ECU 71 has an abnormality in the discharge pressure of oil discharged from the oil pump 64. Since the abnormality signal is output to the warning lamp 75 on the condition that the oil is detected, the driver can be warned that the oil in the oil pan 62 is insufficient. For this reason, it is possible to prompt the driver to check the oil in the oil pan 62 or to replenish the oil pan 62 with oil.

  In addition, the control device 70 according to the present embodiment determines the period from when the engine ECU 71 supplies the oil Oi stored in the oil pan 62 to the high-pressure fuel pump 4 by the oil pump 64 until the oil pan 62 collects the oil Oi. It is set to the lubricating oil circulation period, and the time during which the pressure value of the oil discharge pressure discharged from the oil pump 64 falls below a predetermined value within the continuous lubricating oil circulation period is integrated, and this integrated value is determined. An oil discharge pressure abnormality detection condition is that the value exceeds the value.

For this reason, when the fluctuation cycle of the oil discharge pressure becomes long, it can be detected that the oil pump 64 is in the air sucking state and the oil in the oil pan 62 is insufficient.
In the present embodiment, an example in which the control device 70 for an internal combustion engine is applied to an internal combustion engine for a vehicle has been described. However, the present invention is applicable if an internal combustion engine is used as a power source, for example, a so-called hybrid vehicle The present invention can be applied not only to an internal combustion engine mounted on a motorcycle or a motorcycle but also to an internal combustion engine mounted on a vehicle other than a vehicle such as a ship or a construction machine.

  As described above, the control device for an internal combustion engine according to the present invention burns into the contact portion between the plunger and the cylinder and the contact portion between the lifter and the lifter guide when the lubricating oil stored in the lubricating oil storage means is insufficient. This is effective as a control device for an internal combustion engine having a lubricating oil supply device that lubricates a high-pressure fuel pump that supplies high-pressure fuel to a delivery pipe.

2 Feed pump 4 High pressure fuel pump 5 Delivery pipe (fuel reservoir)
7 Low pressure fuel pipe (low pressure fuel passage)
18 Driving cam 21 Cylinder 22 Pressurizing chamber 23 Plunger
30 Electromagnetic spill valve (open / close valve)
51 Lifter 55 Compression coil spring (biasing member)
56 Lifter guide 61 Oil supply device (lubricating oil supply device)
62 Oil pan (lubricating oil storage means)
64 Oil pump 70 Control device 71 Engine ECU (pump control means)
75 Warning lamp (Warning means)

Claims (3)

A cylinder having a pressurized chamber in which the fuel pressurized in the feed pressure from the feed pump is supplied, a plunger which is inserted in a freely reciprocating in the cylinder, is connected to the plunger, the lifter for reciprocating the plunger And a lifter guide that houses the lifter and guides the reciprocation of the lifter, a drive cam that reciprocates the lifter, and the cylinder and the lifter, and the lifter is disposed on the drive cam side. a biasing member for biasing the rotational movement of the drive cam by converting the reciprocating motion of the lifter and the plunger, the fuel pressure in the pressure chamber is boosted on the feed pressure or fuel reservoir A high-pressure fuel pump that can be pumped to
A control device for an internal combustion engine including a lubricating oil supply device that supplies lubricating oil stored in the lubricating oil storage means to the high-pressure fuel pump by an oil pump,
Examples abnormality condition that has been detected in the lubricating oil of the discharge pressure discharged from the oil pump, have a pump control means for reducing the fuel pressure in said pressure chamber to said feed pressure,
The pump control unit sets a period from when the lubricating oil stored in the lubricating oil storage unit is supplied to the high-pressure fuel pump by the oil pump until it is collected by the lubricating oil storage unit as a lubricating oil circulation period. And
The time during which the pressure value of the discharge pressure of the lubricating oil discharged from the oil pump falls below a predetermined value within the lubricating oil circulation period that is continuous over time is integrated, and the integrated value is equal to or higher than the determination value. Is a condition for detecting abnormality in the discharge pressure of the lubricating oil . The high-pressure fuel pump has an on-off valve that opens and closes a low-pressure fuel passage that communicates the pressurizing chamber and the feed pump.
The pump control means adjusts the fuel pressure supplied from the pressurizing chamber to the fuel reservoir by controlling the valve closing period of the on-off valve in the process of pressurizing the pressurizing chamber with the plunger.
2. The fuel pressure in the pressurizing chamber is lowered to the feed pressure by controlling the on-off valve to be fully opened on condition that an abnormality in the discharge pressure of the oil pump is detected. Control device for internal combustion engine. Warning means for giving a warning based on an abnormal signal output from the pump control means;
The said pump control means outputs the said abnormality signal to the said warning means on the condition that the abnormality of the discharge pressure of the lubricating oil discharged from the said oil pump was detected. The control apparatus of the internal combustion engine described in 1.

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