JP3982469B2 - Dry sump engine - Google Patents

Description

  The present invention relates to an improvement of a dry sump engine, particularly a dry sump engine for reducing blow-by gas.

  In a reciprocating engine for a general automobile, blow-by gas leaks into the crank chamber from the clearance of the piston ring in the compression stroke for compressing the air-fuel mixture and the explosion stroke in which the air-fuel mixture explodes. This blow-by gas is an unburned gas in which engine oil and evaporated water inside the engine are mixed. It is a cause of deterioration of the engine oil, and it is not preferable to release it to the atmosphere as it is. For this reason, there is a blow-by gas circulation device that forcibly returns blow-by gas generated inside the engine to the combustion chamber again together with fresh air sucked from an intake port formed in the head cover of the engine and performs a combustion process.

  In general, the blow-by gas circulation device is often applied to a wet sump type engine. The structure of the wet sump engine is that the crank chamber is connected to the downstream side of the throttle valve of the intake pipe by a circulation passage having a PCV (positive crankcase ventilation) valve, and the inside of the cylinder head is connected to a breather passage (new Connected to the upstream side of the throttle valve of the intake pipe. With such a configuration, blow-by gas in the crank chamber is forcibly introduced into the intake pipe through the circulation passage due to the negative intake pressure of the engine. At this time, by adjusting the PCV valve, it is possible to adjust the amount of air including the blow-by gas introduced into the intake pipe, and the blow-by gas combustion process is performed while sucking in fresh air required in the engine. It can be carried out.

  On the other hand, there is a dry sump engine compared to a wet sump engine. In the dry sump engine, by separating the oil tank from the engine body, the oil pan shape of the engine body can be made thin, and the engine oil is not stored in the engine body. Therefore, engine oil can be stably supplied to the lubrication system. Therefore, it is often used as a competition engine used under severe conditions.

  This dry sump engine has been rarely used in mass-produced vehicles because of its large number of parts and high cost. However, application of dry sump engines with excellent lubricity to mass-produced vehicles is required, and various proposals have been made.

  In the case of a dry sump engine, for example, the oil pan and the oil tank in the engine body are connected by a feed line and a return line, and the engine oil in the oil tank is pumped to the engine body by the oil pump, and the discharge amount from this oil pump A large exhaust pump pumps air containing lubricated engine oil and blow-by gas from the engine body to the oil tank. The blow-by gas separated from the gas and liquid in the oil tank is recirculated to the upstream side of the throttle valve of the intake pipe through the recirculation passage. Also, fresh air introduced by a fresh air passage connected to the upstream side of the throttle valve of the intake pipe is supplied from the intake pipe into the engine body. At this time, the inside of the oil tank is pressurized due to the difference in discharge amount between the oil supply pump and the discharge pump. Since the inside of the engine body is depressurized, it is possible to force the recirculation of blow-by gas from the oil tank to the intake pipe and the introduction of fresh air containing blow-by gas from the intake pipe into the engine body, and burn the blow-by gas (For example, refer to Patent Document 1).

JP-A-8-240113

  However, in the case of the structure of the dry sump engine described above, air containing blow-by gas is supplied to the upstream side of the throttle valve, and therefore, not all blow-by gas is taken into the engine and combustion processing is necessarily performed. Further, if forced circulation of air containing blow-by gas is performed more than allowable, there is a possibility of leakage to the atmosphere side. At this time, if it is configured to introduce blow-by gas downstream of the throttle valve as in the case of a wet sump engine, the downstream side of the throttle valve is always in a negative pressure state, so all without leaking into the atmosphere. It can be introduced inside the engine. However, in this case, if air containing blow-by gas is forcibly sent from the oil tank side, for example, the engine is supercharged during idling, and idling increases from a desired value, causing fuel consumption to decrease. In addition, when air containing excessive blow-by gas is forcibly sent during traveling, the inside of the engine is supercharged and the effect is reduced when engine braking is required. In the case of a wet sump type engine, a PCV valve is used to avoid such inconvenience. However, when a dry sump type engine is applied to a mass-produced vehicle, cost reduction becomes important, without using a PCV valve or the like. An optimal amount of air including blow-by gas is supplied to the combustion chamber inside the engine, and the combustion process of the blow-by gas is performed smoothly, and this process does not affect the basic operation of the engine such as idling and engine braking. It will be necessary.

  The present invention has been made in view of the above problems, and provides a simple and inexpensive dry sump engine that performs a reduction process of generated blowby gas appropriately and smoothly and does not affect the basic operation of the engine. Objective.

  In order to achieve the above object, the present invention provides an engine body, an oil tank that temporarily stores engine oil to be supplied and circulated to the engine body, and a supply that supplies engine oil from the oil tank to the engine body. A pump, a discharge pump that transfers engine oil circulated in the engine body and air containing blow-by gas generated to the oil tank side, and a supply path that supplies air containing blow-by gas from the oil tank side to the intake pipe A pressure sensor that detects the pressure of the internal space of the engine body, and a pump control unit that controls increase / decrease of the discharge capacity of the discharge pump based on the detection result of the pressure sensor, The supply path is connected to a throttle valve downstream side of the intake pipe, and the pump control unit , The ability changes in the discharge pump, and performs flow amount control of air containing blow-by gas into the combustion chamber of the engine body via the exhaust and an air supply path that includes a blow-by gas from the engine body.

  According to this configuration, the pressure state of the engine body is monitored by the pressure sensor, and increase / decrease control of the discharge capacity of the discharge pump is performed. In other words, by controlling the increase or decrease of the discharge capacity of the discharge pump according to the amount of blow-by gas generated, the air containing the optimum amount of blow-by gas suitable for the driving state of the engine body is discharged and a special valve In accordance with the air containing blow-by gas discharged by the capacity control of the discharge pump, an appropriate amount can be returned to the engine body to perform the blow-by gas combustion process. As a result, with an easy configuration, it becomes possible to perform appropriate drive control of the exhaust pump, and appropriate blow-by gas combustion processing and normal engine combustion operation can be performed.

  In order to achieve the above object, according to the present invention, in the above configuration, the pump control unit controls the internal pressure of the engine body to be a predetermined value or less based on a driving state of the engine body. And

  According to this configuration, the exhaust pump is controlled so that the internal pressure of the engine main body becomes a predetermined value or less, so that the air containing the blowby gas is not discharged more than necessary from the engine main body side, and the engine main body side Therefore, the combustion control of the engine body can be stabilized, the excessive drive of the exhaust pump can be suppressed, and the intake balance of the engine body can be adjusted. Blow-by gas can be processed without affecting it.

  In order to achieve the above object, according to the present invention, in the above-described configuration, the pump control unit is configured to calculate an intake amount of air including blow-by gas required at idling when the engine main body is in an idling state. The exhaust pump is controlled to obtain an engine body.

  According to this configuration, it is possible to control the discharge of air including blowby gas from the engine body during idling and the supply amount to the intake pipe side by controlling the exhaust pump, and stable idling control can be achieved with an easy configuration. While performing, the blow-by gas combustion process can be performed.

  According to the present invention, the pressure state inside the engine body is monitored by the pressure sensor, and increase / decrease control of the discharge capacity of the discharge pump is performed. In other words, by controlling the increase or decrease of the discharge capacity of the discharge pump according to the amount of blow-by gas generated, the air containing the optimum amount of blow-by gas suitable for the driving state of the engine body is discharged and a special valve In accordance with the air containing blow-by gas discharged by the capacity control of the discharge pump, an appropriate amount can be returned to the engine body to perform the blow-by gas combustion process. As a result, with an easy configuration, it becomes possible to perform appropriate drive control of the exhaust pump, and appropriate blow-by gas combustion processing and normal engine combustion operation can be performed.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention (hereinafter referred to as embodiments) will be described with reference to the drawings.

  FIG. 1 is a conceptual diagram of a configuration of a dry sump engine 10 (hereinafter simply referred to as an engine 10) of the present embodiment. The engine 10 is roughly composed of an engine body 12 and an oil tank 14. Although the engine body 12 is simplified in illustration, a plurality of cylinders including pistons 16 and cylinders 18 are arranged in a direction perpendicular to the paper surface. A head cover 22 storing a cylinder head 20 and a camshaft is provided above each cylinder, and a crank chamber 24 is formed below each cylinder. Further, an exhaust manifold (exhaust pipe) 28 is connected to the exhaust valve 26 side, and an intake manifold (intake pipe) 32 is connected to the intake valve 30. On the upstream side of the intake pipe 32, a throttle valve 34, an air flow meter 36, an air cleaner 38, and the like are arranged.

  A discharge pump (for example, an electric scavenge pump) 40 for discharging engine oil circulated in the engine body 12 from the crank chamber 24 is connected to the bottom of the crank chamber 24. The engine oil forcedly discharged by the discharge pump 40 is transferred into the oil tank 14 through an oil separator (for example, a cyclone separator) 42. Then, the engine oil stored in the oil tank 14 is pumped through a supply pump (for example, an electric pump) 44, is fed into the engine body 12 again, and is used for lubrication inside the engine body 12.

  As described above, when the engine body 12 burns the gas containing fuel, the blow-by gas leaks from the gap between the piston 16 and the cylinder 18 that reciprocate and enters the crank chamber 24. This blow-by gas (unburned gas) is mixed with engine oil and evaporated water that circulates in the engine body 12 and is not preferably released into the atmosphere as it is. Also, it remains in the engine body 12 for a long time. Keeping it in contact with engine oil may cause deterioration of engine oil. Therefore, in this embodiment, the air in the crank chamber 24 is sucked together with the engine oil that has fallen to the lower portion of the crank chamber 24 by the discharge pump 40, and the blow-by gas is discharged (scavenged) from the engine body 12 together. Yes. Here, the air used to discharge the blow-by gas is the air that is sucked in by a discharge pump 40, which will be described later, and sucked by the discharge pump 40. The blow-by gas is discharged together with this air, and as a result The inside of the crank chamber 24 is scavenged (ventilated). In other words, the air containing blow-by gas is air that is sucked by the discharge pump 40 from the fresh air intake path in order to ventilate the crank chamber 24.

  The air including blow-by gas and engine oil sucked out by the discharge pump 40 is separated into gas and liquid by the oil separator 42. For example, when a cyclone separator is used, engine oil and solids such as combustion debris and metal powder move to the inner wall surface of the cyclone separator, and the gas portion is fed into a supply pipe (supply path) 46 connected to the intake pipe 32. It is. At this time, since the oil separator 42 is pressurized by the operation of the discharge pump 40, the air containing blow-by gas is pumped to the intake pipe 32 side according to the operation amount of the discharge pump 40. On the other hand, the engine oil falls along the inner wall surface of the cyclone separator and is stored in the oil tank 14. Further, the solid matter is collected on the inner wall surface of the cyclone separator, and can be recovered and discarded as necessary.

  The engine oil stored in the oil tank 14 passes through the circulation path 48 by the supply pump 44 and is again pumped to the engine body 12 side, and is used for lubrication inside the engine body 12.

  The characteristic matter of the present embodiment is that the pressure inside the engine body 12 is detected, and the drive capacity of the discharge pump 40 is controlled based on the pressure, thereby discharging the blow-by gas generated in the engine body 12 and the engine. It is possible to control the combustion processing amount of blow-by gas by retransfer of blow-by gas to the main body 12, and to stabilize the combustion control of the engine main body 12 without performing special valve control or the like. It is in place.

For this reason, in the present embodiment, a pressure sensor 50 that measures the pressure inside the engine body 12 is disposed on a part of the engine body 12, for example, the head cover 22. Further, the discharge pump 40 for transferring the air containing the engine oil circulated in the engine body 12 and the blow-by gas generated therein to the oil tank side is, for example, an electric pump motor based on the detection result of the pressure sensor 50. By the control, the discharge capacity can be arbitrarily increased or decreased. This increase / decrease control is performed by the pump control unit 52 to which the detection result of the pressure sensor 50 is input. Although not shown in the drawing, the pump control unit 52 includes information from other than the pressure sensor 50, for example, information from the air flow meter 36, intake air upstream of the throttle valve 34 downstream of the air flow meter 36. Information from the intake air temperature sensor 54 disposed in the pipe 32 and the O ₂ sensor 56 provided in the exhaust pipe 28, information from the throttle position sensor for detecting the position of the throttle valve 34, other information from the atmospheric pressure sensor, Various pieces of information indicating the driving state of the engine 10 such as information from the crank position sensor and information from the cam position sensor are input.

  The flowchart of FIG. 2 shows the basic control procedure of the present embodiment based on the pressure sensor 50.

  The pressure sensor 50 constantly detects the pressure in the engine body 12 and, for example, determines whether or not the pressure in the engine body 12 is negative with respect to atmospheric pressure (S100). As described above, in order to circulate engine oil between the engine main body 12 and the oil tank 14, the engine 10 sucks air including engine oil and blow-by gas by the discharge pump 40, and gas-liquid by the supply pump 44. Only the engine oil after separation is pumped into the engine body 12 to obtain a pressure balance inside the engine body 12.

  By the way, as described above, when the engine 10 is driven, blow-by gas leaks from the gap between the cylinder 18 and the piston 16. The total amount of blow-by gas generated per unit time increases as the engine speed increases. Therefore, when the capacity of the supply pump 44 and the discharge pump 40 is kept constant, if a large amount of blow-by gas is generated (for example, when the rotation speed of the engine 10 is increased), the exhaustion is insufficient. As a result, the blow-by gas is not supplied but the blow-by gas is supplied to the intake pipe 32 and the combustion process can be performed. In such a case, it becomes impossible to control the processing of blow-by gas, and the pressure in the engine body 12 increases, leading to a decrease in engine efficiency due to an increase in internal load. On the other hand, when the amount of blow-by gas generated is small, the discharge pump 40 operates more than necessary, resulting in a decrease in energy efficiency and a reduction in fuel consumption.

  In this embodiment, when the pressure in the engine body 12 increases and becomes higher than atmospheric pressure (detected pressure P <atmospheric pressure), that is, when the rotational speed of the engine 10 increases and a large amount of blow-by gas is generated. In order to positively discharge the blow-by gas from the engine body 12, the pump control unit 52 increases the capacity of the discharge pump 40, for example, stepwise in accordance with an increase in pressure (S101). At this time, the rotational speed of the engine 10 increases, and the air containing more blow-by gas can be combusted. As apparent from FIG. 1, when the capacity of the discharge pump 40 increases, the air containing the blow-by gas discharged from the crank chamber 24 increases, the pressure in the oil separator 42 increases, and the blow-by gas separated from the gas and liquid is increased. Is supplied to the intake pipe 32 via the supply pipe 46 and led to the combustion chamber. At this time, since a large amount of air is required in the combustion chamber with the increase in the rotational speed of the engine 10, a large amount of blow-by gas is generated based on the increase in pressure in the oil separator 42 accompanying the increase in the capacity of the discharge pump 40. Even if it is supplied, all of it can be efficiently burned in the combustion chamber. On the other hand, when the pressure in the engine main body 12 is equal to or lower than the atmospheric pressure in step (S100), it is determined that the discharge pump 40 is performing the discharge operation of the air containing the blowby gas satisfactorily in the initial setting state. Pressure management in the engine body 12 based on the sensor 50 is continued.

  The pressure sensor 50 constantly monitors whether or not the pressure in the engine body 12 is lower than a predetermined value, that is, lower than atmospheric pressure (S102). If the pressure in the engine body 12 becomes lower than atmospheric pressure, the discharge pump For example, the capacity of 40 is decreased stepwise (S103). By continuously performing the increase / decrease control in this manner, an appropriate amount of blow-by gas generated in the engine body 12 is discharged, and an appropriate amount of blow-by gas is supplied to the intake pipe to efficiently discharge and burn the blow-by gas. Can be done. At this time, the exhaust and supply of the blow-by gas can be performed only by controlling the discharge pump 40 based on the detection result of the pressure sensor 50. Therefore, the blow-by gas control can be easily performed without providing a PCV valve or the like as in the prior art. This can be done with a simple configuration.

An appropriate amount of blow-by gas corresponding to the driving state of the engine 10 can be discharged from the crank chamber 24 of the engine body 12. In addition, an appropriate amount of blow-by gas discharged from the crank chamber 24 can be supplied to the combustion chamber that performs the combustion process via the intake pipe 32. As a result, it is suppressed that air containing excessive blow-by gas is forcibly sent into the combustion chamber of the engine body 12 while the vehicle is running. That is, the inside of the combustion chamber is suppressed from being supercharged, and the engine brake can be efficiently operated when the engine brake is necessary.

  By the way, the amount of blow-by gas is generated even during idling rotation, but the pressure in the engine body 12 is increased. In this case, in order to maintain the idling speed, it is necessary to supply an accurate amount of air to the combustion chamber via the intake pipe 32. Normally, the amount of air sucked by the intake pipe 32 is adjusted by the opening / closing amount of the throttle valve 34, but at the time of idling, the throttle valve 34 is basically fully closed. It is not possible to adjust the supply air amount. For example, when a vehicle equipped with the engine 10 moves to a high place where the atmospheric pressure is low and idling there, the amount of air that substantially flows into the combustion chamber because the atmospheric pressure is low, that is, the air density is low. Decreases, and the intake amount at idling becomes unstable. In such a case, naturally, a blow-by gas combustion process is required, and therefore it is necessary to appropriately adjust the introduction balance of fresh air and the introduction of blow-by gas. For this reason, an ISC (idle speed control) valve is normally arranged in a form that bypasses the throttle valve 34, and is controlled so that optimum fresh air is supplied to the combustion chamber during idling.

  On the other hand, according to the present embodiment, as shown in FIG. 1, by adjusting the capacity of the discharge pump 40 to increase or decrease, the pressure in the oil separator 42 is adjusted, that is, the air containing the blow-by gas to the intake pipe 32 is adjusted. The supply amount can be adjusted accurately.

  As described above, since the amount of blow-by gas generated is small during idling, most of the air discharged from the crank chamber 24 by the discharge pump 40 is a fresh air intake connected between the air flow meter 36 and the throttle valve 34. The fresh air is supplied to the engine body 12 such as the head cover 22 via the path 58. Therefore, at the time of idling, it becomes possible to supply substantial fresh air to the intake pipe 32 without passing through the throttle valve 34 by controlling the exhaust pump 40, and it is possible to maintain idling rotation by stable combustion. . Of course, since idling is performed, a slight blow-by gas is generated. However, as described above, most of the air supplied to the intake pipe 32 via the exhaust pump 40 is fresh air, and even if it contains a slight amount of blow-by gas, it does not affect idling and is blow-by by combustion processing by idling. Gas treatment can also be performed simultaneously.

  FIG. 3 shows a flowchart for explaining the control of the discharge pump 40 during idling. Basically, it is preferable that the engine main body 12 is maintained in a negative pressure state equal to or lower than the atmospheric pressure even during idling. Therefore, after the step (S103) in FIG. Time control is performed.

The pump control unit 52 determines whether or not the state of the engine 10 is currently idling from various information idle ON switches and the like that are input (S200). If it is determined that the current state is idling, it is determined whether the air that is currently required for idling is correctly supplied in the combustion chamber (S201). This determination is made, for example, from the amount of air that passes through the air flow meter 36 disposed upstream of the throttle valve 34 of the intake pipe 32 and is sucked into the intake pipe 32, and from the O ₂ sensor 54 provided in the exhaust pipe 28. Based on the information, the amount of air introduced into the combustion chamber is estimated, and determination is made based on whether or not the amount matches a preset air amount. At this time, if the set value of the air sucked from the throttle valve 34 is set to be smaller than the required air amount at idling, the required air amount can be added by the capacity control of the discharge pump 40. That is, if the amount of air required for idling is less than that, the capacity of the discharge pump 40 is increased (S202), and the amount of air supplied from the supply pipe 46 to the downstream of the throttle valve 34 via the oil separator 42. Increase. As described above, when the engine 10 is idling, the blow-by gas generated is very small, and the air sucked from the crank chamber 24 through the discharge pump 40 is substantially fresh. Therefore, by performing the capacity control of the discharge pump 40, it is possible to finely adjust the air supply amount required during idling. This adjustment is continuously performed until the amount of air necessary for idling is reached (S203). When the amount of air required for idling is reached, the capacity of the discharge pump 40 is reduced (S204), and the amount of air required for idling is reduced. The discharge pump 40 is controlled so that it can be maintained. In the flowchart, after step (S204), the process returns to step (S100) in FIG. 2 (reference numeral B). However, during idling, the amount of blow-by gas generated is small and P <atmospheric pressure is substantially maintained. Therefore, in step (S100), if control is performed such that P <atmospheric pressure is performed in the first stage (steps (S100) to (S103)), an affirmative determination is made, and the process proceeds to step (S200). The necessary air amount during idling is continuously monitored.

  Of course, if it is determined in step (S200) that the current state is not idling, such as shifting from the idling state to the accelerator on state, the process returns to step (S100) (arrow B). In this case, since the rotational speed of the engine 10 increases and the amount of blow-by gas generated also increases, a negative determination is made in step (S100), and the processing of the flowchart of FIG. 2 for improving the combustion efficiency of the blow-by gas begins. .

  Therefore, a stable predetermined amount of intake air control can be performed without causing a supercharging state during idling. Of course, the blow-by gas combustion process can be performed at the same time.

  In this way, even when blowby gas combustion processing is performed by performing increase / decrease control of the capacity of the exhaust pump 40 based on the pressure in the engine body 12, the processing is performed in the basic operation of the engine such as idling and engine braking. It is possible to eliminate the PCV valves and ISC valves that are required in the past without influencing, simplifying the configuration of the dry sump engine 10 and contributing to cost reduction. Also, a dry sump engine can be easily used. In the configuration shown in FIG. 1, since the head cover 22 of the engine body 12 and the downstream side of the air flow meter 36 are connected by a fresh air intake passage 58, the amount of air supplied to the engine body 12 (via the head cover 22). The amount of air supplied to the crank chamber 24, the amount of air supplied to the combustion chamber via the intake pipe 32, etc.) can be measured by the air flow meter 36, so that the pressure in the engine body 12 as in the present embodiment. Therefore, even when the increase / decrease control of the capacity of the discharge pump 40 is performed, the amount of air supplied to the combustion chamber can be appropriately managed.

  By the way, in this embodiment using the discharge pump 40 capable of independently adjusting the increase / decrease in capacity, for example, by driving the discharge pump 40 for a predetermined short time (for example, 3 to 5 seconds) after the engine 10 is stopped, Immediately before the engine 10 is stopped, the blow-by gas stored in the crank chamber 24 last can be scavenged. In particular, if blow-by gas remains in the crank chamber 24 after the engine 10 is stopped, the engine oil present on the inner wall of the crank chamber 24 is deteriorated. According to the configuration of the present embodiment, at least engine oil is present by operating the discharge pump 40 so that the pressure in the engine body 12 is lower than the atmospheric pressure for a predetermined time after the engine 10 is stopped. It is possible to prevent the blow-by gas from staying in the oil separator 42 from the crank chamber 24. As a result, engine oil deterioration while the engine 10 is stopped can be suppressed.

  The configuration of the engine 10 shown in FIG. 1 and the processing procedures shown in the flowcharts of FIGS. 2 and 3 are examples. The pressure in the engine body 12 is detected, and the blow-by gas is detected from the engine body 12 side based on the detection result. If the configuration is such that the capacity increase / decrease control of the exhaust pump 40 that sucks in air containing the exhaust gas and the supply of air including blowby gas to the intake pipe 32 is performed by the exhaust pump 40 that has performed the capacity increase / decrease control, the engine 10 is appropriately used. Even if the configuration is changed, the same effect as the present embodiment can be obtained.

It is explanatory drawing explaining the structural concept of the dry sump type engine which concerns on embodiment of this invention. It is explanatory drawing explaining the basic control procedure of the dry sump type engine which concerns on embodiment of this invention. It is explanatory drawing explaining the control procedure at the time of idling of the dry sump type engine which concerns on embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 Dry sump engine (engine), 12 Engine main body, 14 Oil tank, 16 Piston, 18 Cylinder, 20 Cylinder head, 22 Head cover, 24 Crank chamber, 26 Exhaust valve, 28 Exhaust pipe, 30 Intake valve, 32 Intake pipe, 34 Throttle valve, 36 air flow meter, 38 air cleaner, 40 discharge pump, 42 oil separator, 44 supply pump, 46 supply pipe, 48 circulation path, 50 pressure sensor, 52 pump control unit.

Claims (3)

Generated inside the engine body, an oil tank that temporarily stores engine oil to be supplied and circulated to the engine body, a supply pump that supplies engine oil from the oil tank to the engine body, and engine oil that circulates in the engine body A dry sump engine including a discharge pump that transfers air containing blowby gas to the oil tank side, and a supply path that supplies air containing blowby gas from the oil tank side to the intake pipe,
A pressure sensor for detecting the pressure in the internal space of the engine body;
Based on the detection result of the pressure sensor, a pump control unit for increasing / decreasing the discharge capacity of the discharge pump;
Including
The supply path is connected to a throttle valve downstream of the intake pipe, and the pump control unit discharges air including blowby gas from the engine body and burns the engine body through the supply path by increasing or decreasing the capacity of the exhaust pump. A dry sump engine characterized by controlling the inflow of air containing blow-by gas into the chamber. The engine according to claim 1.
The dry control engine is characterized in that the pump control unit controls the internal pressure of the engine body to be a predetermined value or less based on the driving state of the engine body. The engine according to claim 2, wherein
The pump control unit controls a discharge pump so that the engine body can obtain an intake amount of air including blowby gas necessary for idling when the driving state of the engine body is in an idling state. engine.

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