JP2006152826A - Internal combustion engine and controller of internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To share an operating pressure between an emission purification means and the abnormality determination means of a vaporized fuel processing device. <P>SOLUTION: This internal combustion engine comprises a pressure pump 19 causing a negative pressure in a suckingly connected passage 14 connected to the vaporized fuel processing device supplying a vaporized fuel to an intake passage by temporarily adsorbing it to a canister, a suction side selector part 20 installed in the suckingly connected passage 14 and selectively connecting the suction side of the pressure pump 19 to the vaporized fuel processing device or the atmosphere, and exhaust side selector parts 22a and 22b installed in exhaust connection passages 18a and 18b connecting the exhaust side of the pressure pump 19 to an exhaust passage 2 and the atmosphere and opening/closing the exhaust connection passages 18a and 18b. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an internal combustion engine having an abnormality determination unit of an evaporative fuel processing apparatus for supplying evaporative fuel to an engine and an exhaust purification unit for supplying air to an exhaust passage of the engine, and a control device for the internal combustion engine.

  Conventionally, an exhaust gas purification means is provided for an internal combustion engine. This type of exhaust purification means supplies air with a pressure pump to the upstream side of the catalyst in the exhaust passage (see, for example, Patent Document 1).

  On the other hand, conventionally, an evaporative fuel processing device is provided for an internal combustion engine. In this type of fuel vapor processing apparatus, the fuel vapor generated in the fuel tank is temporarily adsorbed by the canister, and the fuel vapor adsorbed by the canister is sucked into the engine (see, for example, Patent Document 2). The evaporative fuel processing apparatus has an abnormality determining means for preventing a situation in which evaporative fuel is released to the outside air due to a perforation in a fuel tank, a canister, a pipe, or the like, or a valve failure. For example, after the air is passed through a bypass passage including an orifice by a pressure pump to obtain a reference pressure, the abnormality determination means generates a negative pressure by the pressure pump in a system such as a fuel tank, a canister, and a pipe blocked by a valve. The determination is made by comparing the negative pressure with the reference pressure.

Japanese Patent Laid-Open No. 8-14035 Japanese Patent Laid-Open No. 11-182369

  By the way, in the exhaust purification means, air is sucked from the air supply passage leading to the atmosphere side by a pressure pump. On the other hand, the abnormality determination means of the evaporated fuel processing apparatus sucks air in the evaporated fuel processing apparatus by a pressure pump. The exhaust purification unit and the abnormality determination unit of the evaporated fuel processing device use separate pressure pumps. That is, conventionally, the pressure pump of the exhaust gas purification unit and the pressure pump of the abnormality determination unit of the evaporated fuel processing device are operated by separate pressure pumps, which is a factor that increases costs.

  Further, in the evaporative fuel processing apparatus, when the evaporative fuel is excessive so that it cannot be adsorbed and partitioned by the canister, the evaporative fuel is opened to the outside (atmosphere). However, it is not preferable to open the evaporated fuel to the outside from the viewpoint of air pollution.

  The present invention has been made to solve the above-described problems caused by the prior art, and an internal combustion engine that can use the operating pressure in the exhaust gas purifying means and the operating pressure in the abnormality determining means of the evaporated fuel processing apparatus in common. It is an object of the present invention to provide a control device for an engine and an internal combustion engine.

  Another object of the present invention is to provide an internal combustion engine and a control device for the internal combustion engine that are capable of processing evaporated fuel inside the engine. And

  In order to solve the above-described problems and achieve the object, an internal combustion engine according to claim 1 generates a negative pressure in a suction connection passage connected to an evaporative fuel processing device that supplies evaporative fuel to an intake passage. A pressure pump, a suction side switching portion provided in the suction connection passage and selectively connecting the suction side of the pressure pump to the evaporated fuel processing device or the atmosphere; and a discharge side of the pressure pump is connected to the exhaust passage and the atmosphere. And a discharge-side switching portion that opens and closes each of the exhaust connection passages.

  An internal combustion engine according to a second aspect of the present invention is the first aspect of the present invention, wherein the suction connection passage has an orifice with respect to a main passage connecting the evaporated fuel processing device and the suction side of the pressure pump. A first air passage having a bypass passage, wherein the suction side switching unit is interposed in the middle of the main passage across the bypass passage, and opens the bypass passage to the atmosphere side to close the main passage; A second air passage that opens the main passage and closes from the atmosphere side; and a third air passage that connects the suction side of the pressure pump to the atmosphere side, and the discharge side switching portion is a discharge side of the pressure pump. A first on-off valve that opens and closes a first exhaust connection passage that connects the air to the atmosphere, and a second on-off valve that opens and closes a second exhaust connection passage that connects the discharge side of the pressure pump to the exhaust passage. It is characterized by.

  An internal combustion engine according to a third aspect of the present invention is the internal combustion engine according to the second aspect, wherein the suction side switching portion includes an auxiliary air passage further connecting the third air passage to the main passage, and an atmosphere of the third air passage. And a third on-off valve for opening and closing the side.

  An internal combustion engine according to a fourth aspect of the present invention is the internal combustion engine according to the third aspect, wherein the suction side switching portion further includes a fourth on-off valve that opens and closes the auxiliary air passage.

  In order to solve the above-described problems and achieve the object, a control device for an internal combustion engine according to a fifth aspect of the present invention provides a negative pressure with respect to a suction connection passage connected to an evaporative fuel processing device that supplies evaporative fuel to an intake passage. Pump driving means for driving the pressure pump for generating the suction pump, and suction side switching unit driving for driving the suction side switching unit for selectively connecting the suction side of the pressure pump to the evaporated fuel processing device or the atmosphere in the suction connection passage And a discharge-side switching unit driving unit that drives a discharge-side switching unit that opens and closes each exhaust connection passage that connects the discharge side of the pressure pump to the exhaust passage and the atmosphere, respectively.

  According to a sixth aspect of the present invention, there is provided a control device for an internal combustion engine according to the fifth aspect of the present invention, wherein the suction connection passage is connected to the main passage connecting the evaporated fuel processing device and the suction side of the pressure pump. A bypass passage having an orifice is provided, and the suction side switching unit driving means opens the bypass passage to the atmosphere side in the suction side switching portion interposed in the middle of the main passage across the bypass passage. A first air passage that closes the main passage, a second air passage that opens the main passage and closes it from the atmosphere side, or a third air passage that connects the suction side of the pressure pump to the atmosphere side is selectively switched and driven The discharge side switching unit driving means includes a first on-off valve that opens and closes a first exhaust connection passage that connects a discharge side of the pressure pump to the atmosphere in the discharge side switching unit, or the pressure pump The exit side and drives the second on-off valve for opening and closing the second exhaust connecting passage connecting the exhaust passage.

  The control apparatus for an internal combustion engine according to a seventh aspect of the present invention is the control device according to the sixth aspect, wherein the suction side switching portion is provided with an auxiliary air passage further connecting the third air passage to the main passage, The suction side switching unit driving means further drives a third on-off valve that opens and closes the atmosphere side of the third air passage.

  According to an eighth aspect of the present invention, there is provided a control device for an internal combustion engine according to the sixth aspect of the invention, wherein the pressure pump is driven in a state where the evaporated fuel processing device and the intake passage are shut off, and the first air passage is selected. Then, the first on-off valve is opened, the second on-off valve is closed, and pressure is detected by a pressure sensor provided in the suction connection passage.

  According to a ninth aspect of the present invention, there is provided a control device for an internal combustion engine according to the sixth aspect of the invention, wherein the pressure pump is driven in a state where the evaporated fuel processing device and the intake passage are shut off, and the first air passage is selected. The first on-off valve is closed and the second on-off valve is opened, and pressure is detected by the pressure sensor provided in the suction connection passage and the pressure sensor provided in the second exhaust connection passage. It is characterized by performing.

  According to a tenth aspect of the present invention, there is provided a control apparatus for an internal combustion engine according to the sixth aspect of the invention, wherein the pressure pump is driven in a state where the evaporated fuel processing device and the intake passage are shut off, and the second air passage is selected. Then, the first on-off valve is opened, the second on-off valve is closed, and pressure is detected by a pressure sensor provided in the suction connection passage.

  According to an eleventh aspect of the present invention, there is provided a control device for an internal combustion engine according to the sixth aspect, wherein the pressure pump is driven in a state in which the evaporated fuel processing device and the intake passage are shut off, and the second air passage is selected. The first on-off valve is closed and the second on-off valve is opened, and pressure is detected by the pressure sensor provided in the suction connection passage and the pressure sensor provided in the second exhaust connection passage. It is characterized by performing.

  According to a twelfth aspect of the present invention, there is provided a control device for an internal combustion engine according to the sixth aspect of the invention, wherein the pressure pump is driven in a state where the evaporated fuel processing device and the intake passage are shut off, and the third air passage is selected. The first on-off valve is closed and the second on-off valve is opened.

  A control device for an internal combustion engine according to a thirteenth aspect of the invention is the control device according to the seventh aspect of the invention, wherein the pressure pump is driven in a state where the evaporated fuel processing device and the intake passage are shut off, and the third air passage is selected. The first on-off valve is closed, the second on-off valve is opened, and the third on-off valve is opened.

  According to a fourteenth aspect of the present invention, there is provided a control device for an internal combustion engine according to the seventh aspect of the present invention, wherein the pressure pump is driven in a state where the evaporated fuel processing device and the intake passage are shut off, and the third air passage is selected. The first on-off valve is closed, the second on-off valve is closed, the third on-off valve is closed, and pressure is detected by a pressure sensor provided in the suction connection passage. To do.

  A control device for an internal combustion engine according to a fifteenth aspect of the invention is the control device according to the seventh aspect of the invention, wherein the pressure pump is driven in a state where the evaporated fuel processing device and the intake passage are shut off, and the third air passage is selected. The first on-off valve is closed, the second on-off valve is opened, and the third on-off valve is closed.

  According to a sixteenth aspect of the present invention, in the control device for an internal combustion engine according to the seventh aspect, the suction side switching unit driving means further drives a fourth on-off valve for opening and closing the auxiliary air passage, and the evaporated fuel processing device. The pressure pump is driven in a state where the intake passage is shut off, the third air passage is selected, the first on-off valve is opened, the second on-off valve is opened, and the third on-off valve is opened. In a state, the fourth on-off valve is closed.

  According to the first aspect of the present invention, the suction side switching unit connects the suction side of the pressure pump to the evaporated fuel processing device, and the discharge side switching unit connects the discharge side of the pressure pump to the atmosphere. It is possible to determine the abnormality of the evaporated fuel processing apparatus by generating a negative pressure. On the other hand, the suction side switching unit connects the suction side of the pressure pump to the atmosphere, and the discharge side switching unit connects the discharge side of the pressure pump to the exhaust passage so that the exhaust gas can be purified by supplying air to the exhaust passage. As a result, the pressure of one pressure pump can be used in common. Further, the excessively evaporated fuel that cannot be supplied to the intake passage by connecting the suction side of the pressure pump to the evaporated fuel processing device by the suction side switching unit and connecting the discharge side of the pressure pump to the exhaust passage by the discharge side switching unit. Can be processed inside the internal combustion engine.

  According to the second aspect of the present invention, the reference pressure through the orifice for determining the abnormality of the evaporated fuel processing apparatus by selectively switching each air passage and the evaporation for determining the abnormality of the evaporated fuel processing apparatus. While obtaining the determination pressure of the fuel processing means, it is possible to obtain air for exhaust purification. Moreover, the air obtained by the pressure pump can be discharged to the atmosphere or the exhaust passage by opening and closing each on-off valve.

  According to the third aspect of the present invention, the air to be sucked in by connecting the suction side of the pressure pump to the atmosphere or the main passage (evaporated fuel processing device) by opening and closing the atmosphere side of the third air passage by the third on-off valve. Can be switched.

  According to the invention of claim 4, the suction side of the pressure pump can be opened and closed with respect to the main passage by opening and closing the auxiliary air passage by the fourth on-off valve.

  According to the invention of claim 5, the suction side switching unit driving means controls connection of the suction side of the pressure pump to the evaporated fuel processing device, and the discharge side switching unit driving means controls connection of the discharge side of the pressure pump to the atmosphere. Thus, a negative pressure is generated in the evaporated fuel processing apparatus, and abnormality determination of the evaporated fuel processing apparatus can be performed. On the other hand, the suction side switching unit driving means controls connection of the pressure pump to the atmosphere, and the discharge side switching unit driving means controls connection of the discharge side of the pressure pump to the exhaust passage to supply air to the exhaust passage. Exhaust gas purification can be performed. As a result, the pressure of one pressure pump can be used in common. Further, the suction side switching unit driving means controls connection of the suction side of the pressure pump to the evaporated fuel processing device, and the discharge side switching unit driving means controls connection of the discharge side of the pressure pump to the exhaust passage to supply the intake passage. Excess evaporative fuel that cannot be handled can be processed inside the internal combustion engine.

  According to the sixth aspect of the present invention, the reference pressure via the orifice for determining the abnormality of the evaporated fuel processing apparatus by selectively switching each air passage and the abnormality determination of the evaporated fuel processing apparatus are determined. While obtaining the determination pressure of the evaporative fuel processing means, it is possible to obtain air for purifying exhaust gas. Further, the air obtained by the pressure pump can be discharged to the atmosphere or the exhaust passage by controlling the opening / closing of each on-off valve.

  According to the seventh aspect of the present invention, the suction side of the pressure pump is connected to the atmosphere or the main passage (evaporated fuel processing device) by controlling the opening and closing of the atmosphere side of the third air passage by the third opening / closing valve driving means. You can switch air.

  According to the invention of claim 8, the first air passage is selected, the first on-off valve is opened, the second on-off valve is closed, and the pressure is detected by the pressure sensor provided in the suction connection passage. Thus, it is possible to obtain the reference pressure via the orifice for performing the abnormality determination.

  According to the ninth aspect of the present invention, the first air passage is selected, the first on-off valve is closed, the second on-off valve is opened, and the pressure sensor and the second exhaust connection passage are provided in the suction connection passage. By detecting the pressure with the pressure sensor provided in the inside, it is possible to determine whether the evaporated fuel is sent to the exhaust passage, the opening / closing abnormality of the second on-off valve, or the failure of the pressure sensor that detects the pressure in the passage. it can.

  According to the invention of claim 10, the second air passage is selected, the first on-off valve is opened, the second on-off valve is closed, and the pressure is detected by the pressure sensor provided in the suction connection passage. Thus, it is possible to obtain the determination pressure of the evaporated fuel processing means for determining the abnormality of the evaporated fuel processing apparatus.

  According to the invention of claim 11, the second air passage is selected, the first on-off valve is closed, the second on-off valve is opened, the pressure sensor and the second exhaust connection passage provided in the suction connection passage By detecting the pressure with the pressure sensor provided in the inside, it is possible to determine whether the evaporated fuel is sent to the exhaust passage, the opening / closing abnormality of the second on-off valve, or the failure of the pressure sensor that detects the pressure in the passage. it can.

  According to the twelfth aspect of the present invention, exhaust purification can be performed by selecting the third air passage and closing the first on-off valve and opening the second on-off valve.

  According to the invention of claim 13, exhaust gas purification is performed by selecting the third air passage and closing the first on-off valve, opening the second on-off valve, and opening the third on-off valve. Can do.

  According to the invention of claim 14, the third air passage is selected, the first on-off valve is closed, the second on-off valve is closed, the third on-off valve is closed, and is provided in the suction connection passage. By detecting the pressure with the pressure sensor, the pulsation of the internal air of the evaporative fuel processing apparatus is eliminated, so that the generation of evaporative fuel that cannot be adsorbed by the canister can be determined by detecting the internal pressure.

  According to the fifteenth aspect of the present invention, the third air passage is selected, the first on-off valve is closed, the second on-off valve is opened, and the third on-off valve is closed to supply the intake passage. Excess evaporated fuel that cannot be burned can be sent to the exhaust passage for combustion treatment.

  According to the sixteenth aspect of the present invention, the third air passage is selected to open the first on-off valve, open the second on-off valve, open the third on-off valve, and close the fourth on-off valve. Thereby, the inside of a channel | path can be made into a clean state with the air from air | atmosphere in the aspect which shields the evaporated fuel from an evaporated fuel processing apparatus.

  Exemplary embodiments of an internal combustion engine and a control device for an internal combustion engine according to the present invention will be described below in detail with reference to the accompanying drawings.

  FIG. 1 is a schematic configuration diagram showing an embodiment of an internal combustion engine and a control apparatus for an internal combustion engine according to the present invention, and FIGS. 2 to 4 are schematic configuration diagrams showing the operation of a switching valve.

  The internal combustion engine and the control device for the internal combustion engine in the present embodiment are for operating the abnormality determination means and the exhaust purification means of the evaporated fuel processing device.

  As shown in FIG. 1, the evaporative fuel processing device is provided in a fuel supply passage 10 connected to an intake passage 1 of an engine (not shown), and includes a fuel tank 11, a canister 12, and a vacuum switching valve (VSV) 13. It is equipped with. The fuel tank 11 stores fuel. The canister 12 adsorbs the evaporated fuel obtained by evaporating the fuel stored in the fuel tank 11. The vacuum switching valve 13 opens according to the negative pressure accompanying the opening of the throttle valve 1 a provided in the intake passage 1. Thus, the evaporated fuel processing apparatus adsorbs the evaporated fuel evaporated in the fuel tank 11 with the canister 12 and supplies the evaporated fuel to the intake passage 1 side.

  As shown in FIG. 1, the internal combustion engine mainly includes a suction connection passage 14, an air supply passage 17, a discharge connection passage 18, a pressure pump 19, and a switching valve 20, as shown in FIG.

  The suction connection passage 14 includes a main passage 15 and a bypass passage 16. The main passage 15 has one end connected to the canister 12 and the other end connected to the suction side of the pressure pump 19. A switching valve 20 is interposed in the middle of the main passage 15.

  The bypass passage 16 is connected across the one end side and the other end side of the main passage 15 so as to bypass the switching valve 20. The bypass passage 16 is provided with an orifice 16a. In the present embodiment, the orifice 16a is provided as a path corresponding to φ0.5 mm, for example. A first pressure sensor 21 is disposed at a connection portion where the bypass passage 16 is connected to the other end of the main passage 15.

  The front end of the air supply passage 17 has an air cleaner 17 a and is open to the atmosphere, and the rear end is connected to the switching valve 20.

  The discharge connection passage 18 includes a first discharge connection passage 18a and a second discharge connection passage 18b. The first discharge connection passage 18 a has one end connected to the discharge side of the pressure pump 19 and the other end connected to the air supply passage 17. The second exhaust connection passage 18b has one end connected to the exhaust side of the pressure pump 19 and the other end connected to the upstream side of the catalyst 2a in the exhaust passage 2 of the internal combustion engine.

  The first discharge connection passage 18a is provided with a first on-off valve 22a composed of an electromagnetic valve for opening and closing the first discharge connection passage 18a. The first on-off valve 22a serves as an exhaust side switching unit of the present invention. In the present embodiment, the first discharge connection passage 18a has the other end connected to the air supply passage 17, but the other end may be directly connected to the air cleaner 17a.

  The second discharge connection passage 18b is provided with a second on-off valve 22b composed of an electromagnetic valve for opening and closing the second discharge connection passage 18b. This 2nd on-off valve 22b makes the exhaust-side switching part of this invention. A second pressure sensor 23 is disposed in the second discharge connection passage 18b. Furthermore, a combination valve 24 that is a combination of an air switching valve 24a and a reed valve 24b is disposed in the second discharge connection passage 18b on the downstream side (exhaust passage 2) of the second pressure sensor 23.

  The pressure pump 19 is an electric air pump, and as described above, the suction side is connected to the other end of the main passage 15, and the discharge side is disposed in the first discharge connection passage 18a and the second discharge connection passage 18b. That is, the pressure pump 19 discharges air sucked from the other end side of the main passage 15 from the first discharge connection passage 18a or the second discharge connection passage 18b.

  The switching valve 20 constitutes an intake side switching portion of the present invention, and is configured in such a manner that the valve body 201 is moved by the stepper motor 202. In the valve body 201, the first air passage 201a and the second air passage 201b are selectively switched in connection with the main passage 15, the bypass passage 16 and the air supply passage 17 with respect to the suction side of the pressure pump 19 during the movement. A third air passage 201c is provided.

  As shown in FIG. 2, the first air passage 201 a connects one end side of the main passage 15 to the air supply passage 17. That is, the first air passage 201 a connects the bypass passage 16 to the air supply passage 17, opens it to the atmosphere and closes the main passage 15, thereby supplying the air to the suction side of the pressure pump 19 via the bypass passage 16. An open passage leading to the passage 17 (atmosphere) is formed.

  As shown in FIG. 3, the second air passage 201 b connects one end side and the other end side of the main passage 15. That is, the second air passage 201b opens the main passage 15 to close the air supply passage 17 and closes it from the atmosphere, thereby connecting the suction side of the pressure pump 19 to the above-described evaporated fuel processing apparatus by the main passage 15. Make a closed passage.

  As shown in FIGS. 1 and 4, the third air passage 201 c forms an inverted V-shaped passage and connects the main passage 15 to the air supply passage 17. That is, the third air passage 201c connects the suction side of the pressure pump 19 to the air supply passage 17 (atmosphere). The third air passage 201c is provided with a third on-off valve 22c including an electromagnetic valve for opening and closing an opening connected to the air supply passage 17 side of the third air passage.

  The third air passage 201c is provided with an auxiliary air passage 201d. The auxiliary air passage 201 d connects the third air passage 201 c to one end side of the main passage 15. That is, when the auxiliary air passage 201d moves the valve body 201 and selects and switches the third air passage 201c, the third air passage 201c (the suction side of the pressure pump 19) is evaporated by the main passage 15 as described above. It is further connected to a fuel processor.

  The air passage 201c, 201b, 201c of the valve body 201 of the switching valve 20 is connected to the other end side of the main passage 15 which is the suction side of the pressure pump 19 and connected to the air from the main passage 15. A check valve 25a is provided to prevent backflow of air into the passages 201c, 201b, 201c. In addition, a check valve 25 b that prevents backflow of air from the bypass passage 16 to one end side of the main passage 15 is disposed on the upstream side (canister 12) side of the orifice 16 a of the bypass passage 16. Further, a check valve 25c for preventing a backflow of gas from the exhaust passage 2 to the second discharge connection passage 18b is disposed at an end portion of the second discharge connection passage 18b connected to the exhaust passage 2.

  As shown in FIG. 1, the vacuum switching valve 13, the pressure pump 19, the switching valve 20, the first on-off valve 22a, the second on-off valve 22b, the third on-off valve 22c, the first pressure sensor 21, and the second pressure sensor 23 described above. Is electrically connected to the control unit 26 and driven and controlled. That is, the control unit 26 can be constituted by a microcomputer, for example, and includes a valve driving means for opening and closing the vacuum switching valve 13, a pump driving means for driving the pressure pump 19, a switching valve 20 and a third on-off valve 22c, which will be described later. A suction-side switching unit driving unit that drives the fourth on-off valve 22d and a discharge-side switching unit driving unit that drives the first on-off valve 22a and the second on-off valve 22b. Further, the control unit 26 inputs detection signals from the first pressure sensor 21 and the second pressure sensor 23. Then, the control unit 26 controls the valve driving means, the pump driving means, the suction side switching section driving means, and the discharge side switching section driving means according to the program and data stored in the storage means in advance, and the first pressure sensor 21. And various situations of the internal combustion engine are determined by the input of the detection signal from the second pressure sensor 23.

  FIG. 5 is a time chart according to abnormality determination of the evaporated fuel processing apparatus. The abnormality determination means is activated after a predetermined time (for example, 5 hours) has elapsed since the internal combustion engine was stopped.

  First, after a predetermined time has elapsed, the control unit 26 drives the switching valve 20 in such a manner that the first air passage 201a is selected. As a result, as shown in FIG. 2, the suction side of the pressure pump 19 communicates with the air supply passage 17 via the bypass passage 16, and an open passage through which the fuel vapor processing apparatus communicates with the air supply passage 17 (atmosphere) is formed. Further, the control unit 26 drives the first on-off valve 22a to the open state, drives the second on-off valve 22b to the closed state, and drives the vacuum switching valve 13 to the closed state. Further, the control unit 26 stops driving the pressure pump 19. In addition, since the 3rd on-off valve 22c is provided in the 3rd air passage 201c and the auxiliary air passage 201d which are not selected, it may be either an open state or a closed state. Further, the air switching valve 24a of the combination valve 24 is driven to a closed state.

  That is, the evaporated fuel processing device is opened to the atmosphere. For this reason, atmospheric pressure is detected by the first pressure sensor 21. The control unit 26 sets the reference value (atmospheric pressure) for abnormality determination while checking the output of the first pressure sensor 21 (see section [A] in FIG. 5).

  Next, the control unit 26 drives the switching valve 20 in such a manner that the second air passage 201b is selected. Thereby, as shown in FIG. 3, a closed passage is formed in which the suction side of the pressure pump 19 is connected to the evaporated fuel processing apparatus via the main passage 15. Further, the control unit 26 drives the first on-off valve 22a to the closed state. At this time, the second on-off valve 22b is closed, the vacuum switching valve 13 is closed, and the drive of the pressure pump 19 remains stopped.

  That is, the evaporated fuel processing apparatus is closed. For this reason, the pressure in the fuel vapor processing apparatus is detected by the first pressure sensor 21. The control unit 26 recognizes the amount of evaporated fuel generated based on the detected pressure. At this time, if the amount of evaporated fuel generated is large, the abnormality determination process is stopped (see section [B] in FIG. 5).

  In the section [B] in FIG. 5 described above, the case where the amount of evaporated fuel generated to stop the abnormality determination process is large when the evaporated fuel processing apparatus is normal (the fuel supply passage 10, the fuel tank). 11 and when the canister 12 is not perforated and the vacuum switching valve 13 is not open and fixed), the reference pressure in the section [C] in FIG. This is a case where the determination pressure becomes a high pressure and erroneous determination is made that the evaporated fuel processing apparatus is abnormal.

  Next, when the generation amount of the evaporated fuel is within a range in which this abnormality determination can be performed, the control unit 26 drives the switching valve 20 in a mode of selecting the first air passage 201a. As a result, as shown in FIG. 2, the suction side of the pressure pump 19 is connected to the bypass passage 16 to form an open passage that leads to the air supply passage 17. Further, the control unit 26 drives the first on-off valve 22a to the open state and drives the pressure pump 19. At this time, the second on-off valve 22b remains closed and the vacuum switching valve 13 remains closed.

  That is, the negative pressure generated by the pressure pump 19 is applied to the bypass passage 16, and the air sucked from the air supply passage 17 through the first air passage 201 a passes through the orifice 16 a, and the first from the discharge side of the pressure pump 19. It is discharged via the air cleaner 17a through the discharge connecting passage 18a and the air supply passage 17. Therefore, the first pressure sensor 21 detects the reference pressure that has passed through the orifice 16a. The reference pressure detected by the first pressure sensor 21 is stored in the control unit 26 (see section [C] in FIG. 5).

  Next, the control unit 26 drives the switching valve 20 in such a manner that the second air passage 201b is selected. As a result, as shown in FIG. 3, a closed passage is formed in which the suction side of the pressure pump 19 is connected to the evaporated fuel processing apparatus via the main passage 15. At this time, the first on-off valve 22a is in the open state, the second on-off valve 22b is in the closed state, the vacuum switching valve 13 is in the closed state, and the pressure pump 19 remains driven.

  That is, the negative pressure generated by the pressure pump 19 is applied to the evaporated fuel processing apparatus via the main passage 15, and the air in the evaporated fuel processing apparatus is sucked and the first discharge connection path 18 a and It is discharged through an air cleaner 17a through an air supply passage 17. For this reason, the pressure (determination pressure) in the evaporated fuel processing apparatus is detected by the first pressure sensor 21. Then, the determination pressure detected by the first pressure sensor 21 is compared with the reference pressure previously stored in the control unit 26.

  In comparison, when the fuel supply passage 10, the fuel tank 11, and the canister 12 are perforated or the vacuum switching valve 13 is fixed open, the determination pressure is higher than the reference pressure ([[ D] See section d1). As a result, it can be determined that there is an abnormality in the evaporated fuel processing apparatus. In this case, if the leak in the closed state of the perforation or vacuum switching valve 13 is equivalent to φ0.5 mm of the orifice 16a, the determination pressure is equivalent to the reference pressure, and if it is abnormal perforation or leakage, the determination pressure is the reference. The pressure is higher than the pressure. On the other hand, when the fuel supply passage 10, the fuel tank 11 and the canister 12 are not perforated and the vacuum switching valve 13 is not open and fixed, the determination pressure becomes a pressure lower than the clear level lower than the reference pressure (see FIG. 5). [D] See section d2). As a result, it can be determined that the fuel vapor processing apparatus is normal (see section [D] in FIG. 5).

  Next, when the fuel vapor processing apparatus is normal, the control unit 26 stops driving the pressure pump 19 and opens the vacuum switching valve 13 following the state at the time of the above determination ([D] section in FIG. 5). Drive to the state. Thereby, the closed passage connected to the evaporated fuel processing apparatus is opened by the vacuum switching valve 13. For this reason, the operation of the vacuum switching valve 13 can be confirmed. That is, it can be determined that the operation of the vacuum switching valve 13 is good based on the pressure increase amount per unit time detected by the first pressure sensor 21. On the other hand, when there is no pressure increase per unit time detected by the first pressure sensor 21, it can be determined that the vacuum switching valve 13 is closed and fixed (see section [E] in FIG. 5).

  Finally, the control unit 26 drives the vacuum switching valve 13 to the closed state following the state at the time of confirming the operation of the vacuum switching valve 13 (section [E] in FIG. 5), and selects the first air passage 201a. The switching valve 20 is driven in a manner. Thereby, as shown in FIG. 2, an open passage through which the fuel vapor processing apparatus communicates with the air supply passage 17 is formed. That is, the evaporated fuel processing device is opened to the atmosphere. For this reason, atmospheric pressure is detected by the first pressure sensor 21. The control unit 26 finally confirms the atmospheric pressure (see section [F] in FIG. 5). Thereafter, the control unit 26 notifies all the determination results. As described above, the abnormality determination unit is activated.

  The exhaust gas purification means is operated 30 to 60 seconds after the internal combustion engine is started. When the internal combustion engine is started, the control unit 26 drives the switching valve 20 in such a manner that the third air passage 201c is selected. Thereby, as shown in FIG. 4, an open passage is formed in which the suction side of the pressure pump 19 is directly connected to the air supply passage 17. The control unit 26 drives the air switching valve 24a of the combination valve 24 to an open state, drives the second on-off valve 22b and the third on-off valve 22c to an open state, and drives the first on-off valve 22a to a closed state. Then, the vacuum switching valve 13 is driven to the closed state. Further, the control unit 26 drives the pressure pump 19.

  That is, the negative pressure generated by the pressure pump 19 is applied to the air supply passage 17, and the air sucked from the air supply passage 17 (air cleaner 17a) through the third air passage 201c is second from the discharge side of the pressure pump 19. The exhaust passage 2 is reached via the discharge connection passage 18b. For this reason, secondary air is sent to the exhaust passage 2 and the unburned fuel in the exhaust passage 2 is combusted. As a result, the catalyst 2a provided in the exhaust passage 2 is warmed and a normal air purification function by the catalyst 2a is obtained. As described above, the exhaust gas purification means is operated.

  Note that when the third air passage 201c is selected in the operation of the exhaust purification means, the second pressure sensor 23 provided in the second exhaust connection passage 18b causes the pressure generated in the second exhaust connection passage 18b by the pressure pump 19. Is detected. Thereby, it can be diagnosed whether the pressure pump 19 is working normally. The second pressure sensor 23 detects the pressure when the pressure pump 19 is driven to open and close the air switching valve 24a and the second opening / closing valve 22b. Therefore, it is determined whether the air switching valve 24a and the second on-off valve 22b are normal.

  In connection with the operation different from the above, when the first air passage 201a or the second air passage 201b is selected and the pressure pump 19 is driven, the control unit 26 drives the first on-off valve 22a to the closed state, 2 The on-off valve 22b is driven to the open state. Thereby, the evaporated fuel is discharged to the exhaust passage 2 through the second discharge connection passage 18b. That is, the first pressure sensor 21 and the second pressure sensor 23 detect the pressure, respectively. For this reason, based on the pressure fluctuation detected by each of the pressure sensors 21 and 23, it is determined whether the second on-off valve 22b is abnormally opened or closed, or any one of the pressure sensors 21 and 23 has failed.

  Further, when the first air passage 201a or the second air passage 201b is selected and the pressure pump 19 is driven and malfunctions, the control unit 26 switches the first on-off valve 22a and the second on-off valve 22b. Drive to the closed state. Thereby, the evaporated fuel is not discharged outside the engine (atmosphere).

  When the third air passage 201c is selected, the control unit 26 drives the first on-off valve 22a, the second on-off valve 22b, the third on-off valve 22c, and the vacuum switching valve 13 to the closed state. Thereby, each passage is closed and the pulsation of the internal air of the fuel tank 11 is eliminated. That is, the first pressure sensor 21 does not detect noise generated from the pulsation of the internal air of the fuel tank 11. For this reason, the closed internal pressure is detected by the first pressure sensor 21 to determine the generation of evaporated fuel that cannot be adsorbed by the canister 12.

  When the amount of evaporated fuel generated is large, the control unit 26 drives the pressure pump 19 by opening the second on-off valve 22b and the air switching valve 24a from the state where the amount of evaporated fuel generated is determined. Thereby, the evaporated fuel that cannot be adsorbed by the canister 12 of the evaporated fuel processing apparatus is sent to the exhaust passage 2 and burned. The fact that the amount of evaporated fuel generated is large can be detected in the section [B] in FIG. 5 when the abnormality determination means of the evaporated fuel processing apparatus described above is operating. Sometimes the third air passage 201c is selected to drive the first on-off valve 22a, the third on-off valve 22c and the vacuum switching valve 13 to the closed state, and to drive the second on-off valve 22b and the air switching valve 24a to the open state. The pressure pump 19 may be driven.

  In addition, when the third air passage 201c is selected and the pressure pump 19 is operating and malfunctions, the control unit 26 drives the second on-off valve 22b to the closed state, and turns on the first on-off valve 22a. Drive to open state. Thereby, the unnecessary secondary air sucked by the pressure pump 19 is not discharged to the exhaust passage 2 but is discharged to the air cleaner 17a. Furthermore, when the third air passage 201c is selected, if the pressure pump 19 is operating and malfunctions, the control unit 26 drives the first on-off valve 22a and the second on-off valve 22b to the closed state. Thereby, unnecessary secondary air sucked by the pressure pump 19 is not discharged to the exhaust passage 2 and the air cleaner 17a.

  As described above, in the internal combustion engine and the control device for the internal combustion engine of the present embodiment, the operating pressure of the pressure pump 19 is used in common with the abnormality determination means and the exhaust purification means of the evaporated fuel processing device. It becomes possible.

  In the internal combustion engine of the present embodiment, the suction side switching unit (switching valve 20) and the discharge side switching unit are used to switch the common operating pressure of the pressure pump 19. The suction side switching unit includes the switching valve 20 (first air passage 201a, second air passage 201b, and third air passage 201c) and a third on-off valve 22c provided in the third air passage 201c. The exhaust side switching portion includes a first on-off valve 22a provided in the first discharge connection passage 18a and a second on-off valve 22b provided in the second discharge connection passage 18b.

  That is, when the first air passage 201a or the second air passage 201b is selected by the switching valve 20, the first on-off valve 22a and the second on-off valve 22b are opened or closed, respectively, as follows. An effect is obtained. Specifically, the abnormality determination unit of the evaporated fuel processing apparatus can be normally operated by mainly opening the first on-off valve 22a and closing the second on-off valve 22b. Further, by closing the first on-off valve 22a and opening the second on-off valve 22b, the fuel vapor is sent to the exhaust passage 2, the open / close abnormality of the second on-off valve 22b, or any pressure sensor. It becomes possible to determine the failure of 21 and 23. Further, by closing the first on-off valve 22a and the second on-off valve 22b, it is possible to prevent the situation where the evaporated fuel is discharged to the outside (atmosphere) of the internal combustion engine when the pressure pump 19 is operated erroneously. It becomes possible.

  In addition, when the third air passage 201c is selected by the switching valve 20, the first on-off valve 22a, the second on-off valve 22b, and the third on-off valve 22c are opened or closed, respectively, as follows. An effect is obtained. Specifically, the exhaust purifying means can be normally operated by closing the first on-off valve 22a and opening the second on-off valve 22b and the third on-off valve 22c. Further, by closing the first on-off valve 22a, the second on-off valve 22b, and the third on-off valve 22c, the pulsation of the internal air of the fuel tank 11 is eliminated, so that the first pressure sensor 21 detects the internal pressure. It is possible to determine the generation of evaporated fuel that cannot be absorbed by the canister 12. In addition, the first on-off valve 22a is closed, the second on-off valve 22b is opened, and the third on-off valve 22c is closed, so that excessive evaporative fuel that cannot be adsorbed by the canister 12 of the evaporative fuel processing apparatus can be obtained. It can be sent to the exhaust passage 2 and burned. Further, when the first on-off valve 22a is opened, the second on-off valve 22b is closed, and the third on-off valve 22c is opened, the pressure pump 19 is operated in the case where the pressure pump 19 is operated erroneously. The sucked unnecessary secondary air can be discharged to the air cleaner 17a without being discharged to the exhaust passage 2. Further, by closing the first on-off valve 22a, closing the second on-off valve 22b, and opening the third on-off valve 22c, unnecessary secondary air sucked by the pressure pump 19 is discharged into the exhaust passage 2 and the air cleaner. It becomes possible to prevent the situation of discharging to 17a.

  Further, when the first air passage 201a, the second air passage 201b or the third air passage 201c is selected and the pressure pump 19 is driven, when the first on-off valve 22a is closed and fixed, the control unit 26 The first on-off valve 22a is driven to the open state, and the second on-off valve 22b is driven to the closed state. Thereby, the first on-off valve 22a side becomes a high pressure, and it is possible to temporarily eliminate the closed adhering of the first on-off valve 22a. When the second on-off valve 22b is closed and fixed, the control unit 26 drives the second on-off valve 22b to the open state and drives the first on-off valve 22a to the closed state. Thereby, the second on-off valve 22b side becomes a high pressure, and it is possible to temporarily eliminate the closed adhering of the second on-off valve 22b.

  In the embodiment described above, as shown in FIG. 6, a fourth on-off valve 22d made of an electromagnetic valve or the like for opening / closing the auxiliary air passage 201d is arranged on the auxiliary air passage 201d provided in the third air passage 201c. You may set up. The fourth on-off valve 22d is connected to the control unit 26. In this case, when the third air passage 201c is selected to perform the exhaust gas purification, the evaporated fuel from the evaporated fuel processing device is blocked by driving the fourth on-off valve 22d to the closed state. In this manner, the secondary air can be sent to the exhaust passage 2. Further, separately from the exhaust purification, the third air passage 201c is selected, the fourth on-off valve 22d is driven to the closed state, and the first on-off valve 22a, the second on-off valve 22b, and the third on-off valve 22c are opened. By driving to the inside, the inside of the passage is made clean with the air from the air supply passage 17 in a manner that blocks the fuel vapor from the fuel vapor processing apparatus. If the inside of the passage is in a clean state, the operating pressure of the pressure pump 19 can be used in common for means other than the abnormality determination means and the exhaust purification means of the evaporated fuel processing apparatus.

  As described above, the internal combustion engine according to the present invention is useful for controlling the operating pressure related to the abnormality determining means of the evaporated fuel processing device and the operating pressure related to the exhaust purification means, and in particular, the operation of one pressure pump. It is suitable for using pressure in common.

1 is a schematic configuration diagram showing an embodiment of an internal combustion engine and a control device for an internal combustion engine according to the present invention. It is a schematic block diagram which shows operation | movement of a switching valve. It is a schematic block diagram which shows operation | movement of a switching valve. It is a schematic block diagram which shows operation | movement of a switching valve. It is a time chart which concerns on abnormality determination of an evaporative fuel processing apparatus. It is a schematic block diagram which shows a 4th on-off valve.

Explanation of symbols

Reference Signs List 1 intake passage 1a throttle valve 2 exhaust passage 2a catalyst 10 fuel supply passage 11 fuel tank 12 canister 13 vacuum switching valve 15 main passage 16 bypass passage 16a orifice 17 air supply passage 17a air cleaner 18 discharge connection passage 18a first discharge connection passage 18b first 2 discharge connection passage 19 pressure pump 20 switching valve 201 valve body 201a first air passage 201b second air passage 201c third air passage 201d auxiliary air passage 202 stepper motor 21 first pressure sensor 22a first on-off valve 22b second on-off valve 22c 3rd on-off valve 22d 4th on-off valve 23 2nd pressure sensor 24 Combination valve 24a Air switching valve 24b Reed valve 25a Check valve 25b Check valve 25c Check valve 26 Control unit

Claims (16)

A pressure pump for generating a negative pressure with respect to a suction connection passage connected to an evaporative fuel processing device for supplying evaporative fuel to an intake passage;
A suction-side switching unit that is provided in the suction connection passage and selectively connects the suction side of the pressure pump to the evaporated fuel processing device or the atmosphere;
A discharge-side switching portion that opens and closes each exhaust connection passage provided in each exhaust connection passage connecting the discharge side of the pressure pump to the exhaust passage and the atmosphere; and
An internal combustion engine comprising: The suction connection passage has a bypass passage having an orifice with respect to a main passage connecting the evaporated fuel processing device and the suction side of the pressure pump;
The suction side switching unit is interposed in the middle of the main passage across the bypass passage, and opens the first passage and the main passage to open the bypass passage to the atmosphere side and close the main passage. A second air passage that is closed from the atmosphere side, and a third air passage that connects the suction side of the pressure pump to the atmosphere side,
The discharge side switching unit includes a first on-off valve that opens and closes a first exhaust connection passage that connects the discharge side of the pressure pump to the atmosphere, and a second exhaust connection passage that connects the discharge side of the pressure pump to the exhaust passage. The internal combustion engine according to claim 1, further comprising a second on-off valve that opens and closes.   The suction side switching unit further includes an auxiliary air passage that further connects the third air passage to the main passage, and a third on-off valve that opens and closes the atmosphere side of the third air passage. Item 3. The internal combustion engine according to Item 2.   The internal combustion engine according to claim 3, wherein the suction side switching unit further includes a fourth on-off valve that opens and closes the auxiliary air passage. A pump driving means for driving a pressure pump for generating a negative pressure with respect to a suction connection passage connected to an evaporative fuel processing device for supplying evaporative fuel to an intake passage;
A suction side switching unit driving means for driving a suction side switching unit for selectively connecting the suction side of the pressure pump to the evaporated fuel processing device or the atmosphere in the suction connection passage;
A control device for an internal combustion engine, comprising: a discharge-side switching unit driving means for driving a discharge-side switching unit that opens and closes each exhaust connection passage that connects the discharge side of the pressure pump to an exhaust passage and the atmosphere, respectively. . The suction connection passage is provided with a bypass passage having an orifice with respect to a main passage connecting between the evaporated fuel processing device and the suction side of the pressure pump,
The suction side switching unit driving means includes a first air passage that opens the bypass passage to the atmosphere side and closes the main passage in the suction side switching portion interposed in the middle of the main passage across the bypass passage, Selectively switching and driving a second air passage that opens the main passage and closes it from the atmosphere side, or a third air passage that connects the suction side of the pressure pump to the atmosphere side;
The discharge side switching unit driving means is a first on-off valve that opens and closes a first exhaust connection passage that connects the discharge side of the pressure pump to the atmosphere, or the discharge side of the pressure pump is the exhaust passage in the discharge side switching unit. 6. The control device for an internal combustion engine according to claim 5, wherein a second on-off valve that opens and closes a second exhaust connection passage connected to the engine is driven.   The suction side switching portion is provided with an auxiliary air passage that further connects the third air passage to the main passage, and the suction side switching portion driving means opens and closes the atmosphere side of the third air passage. 7. The control device for an internal combustion engine according to claim 6, wherein the valve is further driven.   The pressure pump is driven in a state where the evaporated fuel processing device and the intake passage are shut off, the first air passage is selected, the first on-off valve is opened, the second on-off valve is closed, The control device for an internal combustion engine according to claim 6, wherein the pressure is detected by a pressure sensor provided in the suction connection passage.   The pressure pump is driven in a state where the evaporative fuel processing device and the intake passage are shut off, the first air passage is selected, the first on-off valve is closed, the second on-off valve is opened, 7. The control device for an internal combustion engine according to claim 6, wherein the pressure is detected by a pressure sensor provided in the suction connection passage and a pressure sensor provided in the second exhaust connection passage.   The pressure pump is driven in a state where the evaporated fuel processing device and the intake passage are shut off, the second air passage is selected, the first on-off valve is opened, the second on-off valve is closed, The control device for an internal combustion engine according to claim 6, wherein the pressure is detected by a pressure sensor provided in the suction connection passage.   The pressure pump is driven in a state where the evaporated fuel processing device and the intake passage are shut off, the second air passage is selected, the first on-off valve is closed, the second on-off valve is opened, 7. The control device for an internal combustion engine according to claim 6, wherein the pressure is detected by a pressure sensor provided in the suction connection passage and a pressure sensor provided in the second exhaust connection passage.   The pressure pump is driven in a state where the evaporated fuel processing device and the intake passage are shut off, the third air passage is selected, the first on-off valve is closed, and the second on-off valve is opened. The control device for an internal combustion engine according to claim 6.   The pressure pump is driven in a state where the evaporative fuel processing device and the intake passage are shut off, the third air passage is selected, the first on-off valve is closed, the second on-off valve is opened, the first The control device for an internal combustion engine according to claim 7, wherein the three on-off valve is opened.   The pressure pump is driven in a state where the evaporated fuel processing device and the intake passage are shut off, the third air passage is selected, the first on-off valve is closed, the second on-off valve is closed, the first 8. The control device for an internal combustion engine according to claim 7, wherein the on-off valve is closed and the pressure is detected by a pressure sensor provided in the suction connection passage.   The pressure pump is driven in a state where the evaporative fuel processing device and the intake passage are shut off, the third air passage is selected, the first on-off valve is closed, the second on-off valve is opened, the first The control device for an internal combustion engine according to claim 7, wherein the three on-off valve is closed.   The suction side switching unit driving means further drives a fourth on-off valve that opens and closes the auxiliary air passage, drives a pressure pump in a state where the evaporated fuel processing device and the intake passage are shut off, and the third air passage 8 is selected, and the first on-off valve is opened, the second on-off valve is opened, the third on-off valve is opened, and the fourth on-off valve is closed. The internal combustion engine control device described.

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