JP5978502B2 - Engine condensate drain - Google Patents

Description

  The present invention relates to a condensed water discharge device for an engine.

  In an internal combustion engine equipped with a low pressure EGR (Exhaust Gas Recirculation), an oil component in blow-by gas discharged from a breather hose and intake air are generated through an intercooler in an intake passage. Condensed water mixes, and part of it is emulsified to produce a substance with a higher viscosity than water. Further, the oil component and the unburned component in the blow-by gas are combined to generate a deposit.

  These substances adhere to the inner wall of the intake passage and gradually adhere as the temperature changes repeatedly. As a solution to this problem, the following Patent Document 1 discloses a technique for removing adhered substances in a compressor in a turbocharger provided in an intake passage.

JP 2005-226476 A Japanese Patent No. 4803007

  However, as disclosed in Patent Document 2 below, when the bypass passage is provided in the intake passage, the bypass passage 24 having a relatively small inner diameter is blocked by the adhering substance 38 as shown in FIG. Is concerned.

  When the bypass passage is blocked, it becomes difficult to discharge condensed water, oil, and the like from the intake passage, which may cause the intake passage to be blocked.

  Therefore, an object of the present invention is to provide a bypass passage that discharges condensed water from the intake passage, and to control the washing of the bypass passage during engine operation to remove the adhering substances attached to the inner wall of the bypass passage.

The condensed water discharge device for an engine according to the first invention for solving the above-mentioned problem is
A condensed water storage tank provided downstream of the intercooler in the intake passage;
A bypass passage communicating the condensate storage tank and the vicinity of the intake manifold of the intake passage;
A washer fluid tank for storing a washer fluid for cleaning the inner wall of the bypass passage;
A washer fluid passage communicating the bypass passage and the washer fluid tank;
A first on-off valve provided at an end of the bypass passage on the side of the condensed water storage tank;
A second on-off valve provided at an end of the bypass passage on the intake manifold side;
A third on-off valve provided in the washer fluid passage;
A throttle valve provided downstream of the condensed water storage tank in the intake passage;
Control means for controlling the open / close state of the first open / close valve, the second open / close valve, the third open / close valve and the throttle valve according to the acceleration / deceleration state of the vehicle,
The control device sets the first on-off valve, the second on-off valve, the third on-off valve, and the like so as to introduce the washer fluid into the bypass passage after the inside of the bypass passage is brought into a negative pressure state during vehicle deceleration. The opening / closing state of the throttle valve is controlled.

The condensed water discharge device for an engine according to the second invention for solving the above-mentioned problems is
In the condensed water discharge device for an engine according to the first aspect of the invention,
The control means includes
During deceleration of the vehicle, the first on-off valve is closed, the second on-off valve is opened, the third on-off valve is closed, and the throttle valve is closed, so that the inside of the bypass passage is in a negative pressure state. After the deceleration, the first on-off valve is closed, the second on-off valve is closed, and the third on-off valve is opened, so that the washer liquid stored in the washer liquid tank is The first on-off valve is opened, the second on-off valve is opened, the third on-off valve is closed, and the vehicle is introduced into the bypass passage through the washer fluid passage. Control is performed to discharge the washer fluid in the bypass passage to the intake passage by closing the throttle valve.

An engine condensate discharge device according to a third aspect of the present invention for solving the above problem
In the condensed water discharge device for an engine according to the first or second invention,
An exhaust gas recirculation device is further provided for sending exhaust gas from the downstream side of the turbocharger in the exhaust passage to the upstream side of the turbocharger in the intake passage.

  According to the condensate drainage device for an engine according to the first aspect of the invention, the bypass passage can be washed with the washer liquid to remove the adhering substances attached to the inner wall of the bypass passage, and the washed washer liquid is evaporated in the engine. Can be made.

  According to the condensate drainage device for an engine according to the second aspect of the present invention, when the vehicle is decelerated, the inside of the bypass passage is brought into a negative pressure state, and the washer fluid is introduced into the bypass passage after the deceleration ends. After washing with the washer liquid, it is possible to perform control to discharge the washer liquid to the intake passage and evaporate in the engine at the next deceleration.

  According to the condensed water discharge device for an engine according to the third aspect of the invention, when the exhaust gas recirculation device is used, the oil component in the blow-by gas and the condensed water derived from the exhaust gas are mixed and partly emulsified to form water. An adhering substance having a higher viscosity is generated, and the adhering substance is easily fixed to the inner wall of the bypass passage. Therefore, the effect of the present apparatus that can clean the inner wall of the bypass passage is more remarkably exhibited.

It is the schematic of the internal combustion engine provided with the condensed water discharge apparatus of the engine which concerns on Example 1 of this invention. It is a flowchart explaining the action | operation of the condensed water discharge apparatus of the engine which concerns on Example 1 of this invention. It is the schematic explaining the adhering substance adhering to the inner wall of a bypass channel.

  Hereinafter, an engine condensate discharge device according to the present invention will be described with reference to the accompanying drawings.

  An engine condensed water discharger according to Embodiment 1 of the present invention will be described in detail with reference to FIG. FIG. 1 is a schematic view of an internal combustion engine equipped with EGR. The internal combustion engine includes an intake passage 12, an exhaust passage 13, a catalyst 14, an engine 15, a turbocharger 21, an intercooler 22, a condensed water storage tank 23, a bypass passage 24, a first on-off valve 25, and a second on-off valve 26. , High pressure EGR 27, high pressure throttle valve 28, low pressure EGR 30, low pressure throttle valve 31, breather hose 34, washer fluid passage 35, washer fluid tank 36, third open / close valve 37, intake manifold 41, and ECU (Electronic Controlled Unit: electronic control) Device) 42.

  The above-described turbocharger 21 compresses the air in the intake passage 12 to increase the charging efficiency, and is provided so as to straddle the intake passage 12 and the exhaust passage 13. And a turbine on the exhaust passage 13 side (not shown).

  The above-described intercooler 22 cools the intake air sent from the turbocharger 21 and further increases the charging efficiency, and is provided downstream of the turbocharger 21 in the intake passage 12.

  The condensate storage tank 23 described above stores condensate generated by intake air passing through the intercooler 22, and is provided downstream of the intercooler 22 in the intake passage 12.

  The bypass passage 24 described above is a passage for discharging condensed water from the condensed water storage tank 23, and communicates the condensed water storage tank 23 with the vicinity of the intake manifold 41.

  The first on-off valve 25 described above is a valve provided at the end of the bypass passage 24 on the side of the condensed water storage tank 23 and can be opened and closed by the ECU 42.

  The above-described second on-off valve 26 is a valve provided at the end of the bypass passage 24 on the intake manifold 41 side, and can be opened and closed by the ECU 42 like the first on-off valve 25.

  The high-pressure EGR 27 described above is an EGR that sends exhaust gas from between the engine 15 and the turbocharger 21 in the exhaust passage 13 into the intake passage 12 between the intercooler 22 and the engine 15. A high pressure EGR valve 29 for controlling the exhaust gas recirculation amount is provided at a portion where the downstream end of the high pressure EGR 27 joins with the intake passage 12. The high pressure EGR valve 29 is connected to the intake passage 12. It arrange | positions so that it may be located downstream from the high pressure throttle valve 28.

  The high-pressure throttle valve 28 described above is a throttle valve that adjusts the amount of intake air, and is provided in the intake passage 12 on the downstream side of the condensed water storage tank 23.

  The low-pressure EGR 30 is an EGR that sends exhaust gas from the turbocharger 21 in the exhaust passage 13 and the downstream side of the catalyst 14 to the upstream side of the turbocharger 21 in the intake passage 12. The catalyst 14 is a filter that purifies exhaust gas components provided in the exhaust passage 13. The low-pressure EGR 30 is provided with an EGR cooler 33 that cools air passing through the inside, and a low-pressure EGR valve 32 that controls the amount of exhaust gas recirculation is provided at a portion where it joins the intake passage 12.

  The above-described low-pressure throttle valve 31 is a throttle valve that adjusts the intake amount of intake air, and is provided upstream of the low-pressure EGR valve 32 in the intake passage 12.

  The breather hose 34 described above is a passage for sending blow-by gas from the engine 15 to the upstream side of the low-pressure throttle valve 31 in the intake passage 12 (that is, the upstream side of the turbocharger 21).

  The washer liquid tank 36 described above is a tank that stores washer liquid for cleaning the inner wall of the bypass passage 24.

  The washer fluid passage 35 is a washer fluid passage that communicates the bypass passage 24 and the washer fluid tank 36.

  The above-described third on-off valve 37 is a valve provided in the washer fluid passage 35 and is openable and closable by the ECU 42 like the first on-off valve 25 and the second on-off valve 26.

  The above-described ECU 42 determines the acceleration / deceleration state from the accelerator opening of the vehicle, and opens / closes the first on-off valve 25, the second on-off valve 26, the third on-off valve 37, and the high-pressure throttle valve 28 according to the acceleration / deceleration state. And the inner wall of the bypass passage 24 is washed with a washer solution. In addition, regarding the determination of the acceleration / deceleration state described above, it is assumed that the accelerator OFF (fully closed) is decelerated and the accelerator ON is determined to be decelerated (end).

  Hereinafter, the operation of the ECU 42 will be described with reference to the flowchart shown in FIG.

  In step S1, it is determined whether or not the vehicle has traveled akm from the previous cleaning control. If the vehicle is traveling akm, the process proceeds to step S2, and if the vehicle is not traveling akm, this step S1 is repeated until the vehicle is traveling. By this step S1, cleaning control can be performed periodically. It should be noted that a may be appropriately determined in consideration of various conditions.

  In step S2, it is confirmed that the first on-off valve 25, the second on-off valve 26, and the third on-off valve 37 are closed. The on-off valve is normally maintained in a closed state.

  In step S3, accelerator ON / OFF is detected from the accelerator opening, and it is determined whether the accelerator is OFF, that is, whether the vehicle is decelerating. If the accelerator is OFF and the vehicle is decelerating, the process proceeds to step S4. If not decelerating, step S3 is repeated.

  In step S4, the second on-off valve 26 is opened. Thereafter, the high pressure throttle valve 28 is closed. By this step S4, the bypass passage 24 can be set to a negative pressure by utilizing the rotation of the engine 15.

  In step S5, it is determined again whether or not the vehicle is decelerating. Here, it is determined whether the deceleration state of the vehicle has ended. If the vehicle is not decelerating, that is, if the deceleration state is completed, the process proceeds to step S6. If the vehicle is decelerating, step S5 is repeated until the deceleration is completed.

  In step S6, after the deceleration ends, the second on-off valve 26 is closed. Thereafter, the closed state of the high-pressure throttle valve 28 is released.

In step S7, the deceleration time to determine whether it was _one second or more t. If it is t ₁ seconds or more, the process proceeds to step S7, and if it is less than t ₁ seconds, the process proceeds to step S2. Note that t ₁ is determined by calibration. The reason why Step S7 is performed is that if the deceleration time is short, the negative pressure in the bypass passage 24 becomes insufficient, and the washer liquid cannot be sufficiently introduced.

  In step S8, the third on-off valve 37 is opened.

In step S9, measurement is performed by a timer built in the ECU 42, and it is determined whether or not a predetermined time t ₂ seconds has elapsed. If it has elapsed, the process proceeds to step S10, and if it has not elapsed, step S9 is repeated. The predetermined time t ₂ is determined by calibration. At that time, the time is sufficient to introduce the washer liquid.

  Since the bypass passage 24 is at a negative pressure in steps S8 and S9, washer fluid is introduced and filled in the bypass passage 24.

  In step S10, the third on-off valve 37 is closed.

  In step S11, it is determined whether the vehicle is decelerating. If the accelerator is OFF and the vehicle is decelerating, the process proceeds to step S12. If not decelerating, step S11 is repeated.

  In step S12, the first on-off valve 25 and the second on-off valve 26 are opened. Thereafter, the high pressure throttle valve 28 is closed. By this step S12, the washer liquid is discharged from the bypass passage 24 by the differential pressure generated in the bypass passage 24, and the inner wall of the bypass passage 24 is washed.

  In step S13, it is determined whether or not the vehicle deceleration state has ended. If the deceleration state is completed, the process proceeds to step S13, and if the deceleration is being performed, step S13 is repeated until the deceleration is completed.

  In step S14, the closed state of the high pressure throttle valve 28 is released.

  In step S15, the first on-off valve 25 and the second on-off valve 26 are closed. Then, it returns to step S1.

  That is, after the bypass passage 24 is brought into a negative pressure state, the ECU 42 introduces washer fluid from the washer fluid tank 36 to fill the bypass passage 24 with the washer fluid, and then throttles the high-pressure throttle valve 28. The washer liquid in the bypass passage 24 is discharged, and the inner wall of the bypass passage 24 is washed.

  In the above description, the high pressure EGR 27 and the low pressure EGR 30 are provided in the engine condensate discharge apparatus according to the first embodiment. However, the high pressure EGR 27 and the low pressure EGR 30 are not essential components. However, in the internal combustion engine provided with the low pressure EGR 30, as described above, the oil component in the blow-by gas and the condensed water are mixed and partly emulsified to produce an adhering substance having a higher viscosity than water. And since the said adhering substance becomes easy to adhere to the inner wall of the bypass channel 24, the effect of this apparatus is exhibited more notably.

  Although the condensed water discharge device for the engine according to the first embodiment has been described in detail above, in other words, this device includes the condensed water storage tank 23 provided on the downstream side of the intercooler 22 and the condensed water in the intake passage 12. A bypass passage 24 that communicates between the storage tank 23 and the vicinity of the intake manifold 41, a washer fluid tank 36 that stores a washer fluid for cleaning the inner wall of the bypass passage 24, and a bypass passage 24 and the washer fluid tank 36 that communicate with each other. A washer liquid passage 35, a first opening / closing valve 25 provided at the end of the bypass passage 24 on the condensed water storage tank 23 side, and a second opening / closing provided at the end of the bypass passage 24 on the intake manifold 41 side In the valve 26, the third on-off valve 37 provided in the washer liquid passage 35, and the intake passage 12, the condensed water storage tank Open / close state of the first on-off valve 25, the second on-off valve 26, the third on-off valve 37 and the high-pressure throttle valve 28 according to the acceleration / deceleration state of the vehicle. The ECU 42 controls the first on-off valve 25, the second on-off valve 26, and the second on-off valve 26 so that the washer fluid is introduced into the bypass passage 24 after the inside of the bypass passage 24 is brought into a negative pressure state when the vehicle is decelerated. The on-off state of the 3 on-off valve 37 and the high-pressure throttle valve 28 is controlled.

  As a result, the bypass passage 24 can be washed with the washer liquid, the adhering substances adhering to the inner wall of the bypass passage 24 can be removed, and the washed washer liquid can be evaporated in the engine 15.

  The ECU 42 closes the first on-off valve 25, opens the second on-off valve 26, closes the third on-off valve 37, and closes the high-pressure throttle valve 28 when the vehicle decelerates. 24, after the deceleration is completed, the first on-off valve 25 is closed, the second on-off valve 26 is closed, and the third on-off valve 37 is opened, so that it is stored in the washer liquid tank 36. The washer fluid is introduced into the bypass passage 24 through the washer fluid passage 35, and at the next vehicle deceleration, the first on-off valve 25 is opened, the second on-off valve 26 is opened, and the third on-off valve 37 is opened. Is closed and the high-pressure throttle valve 28 is closed, so that the washer fluid in the bypass passage 24 is controlled to be discharged to the intake passage 12.

  Thus, when the vehicle is decelerated, the inside of the bypass passage 24 is set to a negative pressure, and after the deceleration is finished, the washer fluid is introduced into the bypass passage 24. After the inner wall of the bypass passage 24 is washed with the washer fluid, Control can be performed so that the washer fluid is discharged into the intake passage 12 and evaporated in the engine 15.

  Further, the present apparatus may include a low pressure EGR 30 for sending exhaust gas from the downstream side of the turbocharger 21 in the exhaust passage 13 to the upstream side of the turbocharger 21 in the intake passage 12.

  When the low pressure EGR 30 is used in this way, the oil component in the blow-by gas and the condensed water derived from the exhaust gas are mixed, and part of the emulsion is emulsified to generate an adhering substance having a viscosity higher than that of the water. It becomes easy to adhere to the inner wall of the passage 24. Therefore, the effect of the present apparatus that can clean the inner wall of the bypass passage 24 is more remarkably exhibited.

  The present invention is suitable as a condensed water discharge device for an engine.

12 Intake passage 13 Exhaust passage 14 Catalyst (filter)
DESCRIPTION OF SYMBOLS 15 Engine 21 Turbocharger 22 Intercooler 23 Condensate storage tank 24 Bypass passage 25 1st on-off valve 26 2nd on-off valve 27 High pressure EGR
28 High-pressure throttle valve 29 High-pressure EGR valve 30 Low-pressure EGR
31 Low-pressure throttle valve 32 Low-pressure EGR valve 33 EGR cooler 34 Breather hose 35 Washer fluid passage 36 Washer fluid tank 37 Third on-off valve 38 Adhering substance 41 Vehicle speed sensor 42 ECU

Claims (3)

A condensed water storage tank provided downstream of the intercooler in the intake passage;
A bypass passage communicating the condensate storage tank and the vicinity of the intake manifold of the intake passage;
A washer fluid tank for storing a washer fluid for cleaning the inner wall of the bypass passage;
A washer fluid passage communicating the bypass passage and the washer fluid tank;
A first on-off valve provided at an end of the bypass passage on the side of the condensed water storage tank;
A second on-off valve provided at an end of the bypass passage on the intake manifold side;
A third on-off valve provided in the washer fluid passage;
A throttle valve provided downstream of the condensed water storage tank in the intake passage;
Control means for controlling the open / close state of the first open / close valve, the second open / close valve, the third open / close valve and the throttle valve according to the acceleration / deceleration state of the vehicle,
The control device sets the first on-off valve, the second on-off valve, the third on-off valve, and the like so as to introduce the washer fluid into the bypass passage after the inside of the bypass passage is brought into a negative pressure state during vehicle deceleration. A condensate drainage device for an engine which controls an open / close state of the throttle valve. The control means includes
During deceleration of the vehicle, the first on-off valve is closed, the second on-off valve is opened, the third on-off valve is closed, and the throttle valve is closed, so that the inside of the bypass passage is in a negative pressure state. After the deceleration, the first on-off valve is closed, the second on-off valve is closed, and the third on-off valve is opened, so that the washer liquid stored in the washer liquid tank is The first on-off valve is opened, the second on-off valve is opened, the third on-off valve is closed, and the vehicle is introduced into the bypass passage through the washer fluid passage. 2. The engine condensate discharge device according to claim 1, wherein the washer fluid in the bypass passage is controlled to be discharged to the intake passage by closing the throttle valve.   The engine condensation according to claim 1, further comprising an exhaust gas recirculation device that sends exhaust gas to the upstream side of the turbocharger in the intake passage from the downstream side of the turbocharger in the exhaust passage. Water discharge device.

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