JP2016098746A - Evaporated fuel treatment device of engine with supercharger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve a necessary purge flow rate even when a negative pressure generated in an ejector is weak, by reducing pressure loss of a purge passage implementing purging by the negative pressure of the ejector, in an evaporated fuel treatment device of an engine with a supercharger purging a canister by utilizing the negative pressure generated by the ejector.SOLUTION: A purge passage 15 is branched into a first passage 15a and a second passage 15b at a downstream side of a canister 11, the first passage 15a is connected to a downstream side of a throttle valve 23, and the second passage 15b is connected to an upstream side of a supercharger 22, and includes an ejector 13 generating a negative pressure by receiving supercharged air generated by the supercharger 22. An application port 13a is connected to a downstream side of the supercharger 22, a discharge port 13b is inserted into the second passage 15b with a suction port 13c and connected, the suction port 13c is connected to a canister 11 side, the discharge port 13b is connected to an air supply passage side, and the first passage 15a includes a purge valve 12.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an evaporated fuel processing apparatus for a supercharged engine that adsorbs evaporated fuel in a fuel tank to a canister through a vapor passage, and sucks and purges the evaporated fuel adsorbed on the canister into the engine through a purge passage.

  In an engine with a supercharger, a technique has been proposed in which a negative pressure is generated in an ejector using a supercharging pressure by the supercharger, and a canister is purged by the negative pressure (see Patent Document 1 below).

JP 2007-332855 A

  However, in the above conventional technique, a purge valve for controlling the purge amount is provided in the purge passage, so that a necessary and sufficient purge flow rate may not be obtained due to the pressure loss of the purge valve. That is, since the purge valve needs to improve the response of the purge amount control, the valve opening amount is restricted and the pressure loss becomes relatively large. On the other hand, it is difficult in principle to increase the negative pressure generated by the ejector. For this reason, if the negative pressure generated in the ejector is weak, the necessary purge flow rate may not flow.

  In view of such a problem, an object of the present invention is to provide a purge passage for purging with the negative pressure of the ejector in an evaporative fuel processing apparatus for an engine with a supercharger that purges the canister using the negative pressure generated by the ejector. By reducing the pressure loss, a necessary purge flow rate can be made to flow even if the negative pressure generated in the ejector is weak.

  A first aspect of the present invention is provided in an engine with a supercharger, wherein evaporated fuel in a fuel tank is adsorbed by a canister through a vapor passage, and evaporated fuel adsorbed by the canister is sucked into the engine through a purge passage and purged. In the fuel vapor processing apparatus, the purge passage is branched into a first passage and a second passage on the downstream side of the canister by a flow of the evaporated fuel flowing through the purge passage, and the first passage is an air supply passage of the engine And the second passage is connected to the upstream side of the supercharger by the flow of air in the air supply passage, and the supercharge generated by the supercharger. An ejector for generating a negative pressure by receiving air, and an application port for receiving the supercharged air from the supercharger in the ejector is a flow of the air supply to the engine. A discharge port that is connected to the flow side and discharges supercharged air that has flowed into the application port in the ejector is inserted and connected to the second passage together with a suction port that generates negative pressure in the ejector. The suction port is connected to the canister side, the discharge port is connected to the air supply passage side, and the first passage is provided with a purge valve for controlling the flow rate through the first passage.

  According to a second aspect of the present invention, there is provided the on-off valve according to the first aspect, wherein the air flow flowing through the second passage is intermittently controlled.

  According to a third aspect of the present invention, in the second aspect of the present invention, the on-off valve is provided by being inserted into the second passage.

  According to a fourth aspect of the present invention, in the second aspect of the present invention, the on-off valve is provided by being inserted into an application passage where an application port of the ejector is connected to a downstream side of the supercharger.

  According to a fifth aspect of the present invention, in any one of the second to fourth aspects, the on-off valve is an electromagnetic valve that is opened and closed by an electrical signal.

  According to a sixth aspect of the present invention, in any of the second to fourth aspects of the present invention, the on-off valve receives supercharged air generated by the supercharger and is opened when the air pressure is higher than a predetermined pressure. A diaphragm valve that is closed when low.

  According to a seventh aspect of the present invention, there is provided a check valve according to any one of the second to sixth aspects, wherein the check valve prevents air from flowing to the first passage through the second passage.

  According to an eighth aspect of the present invention, in any one of the first to seventh aspects, the ejector includes a plurality of ejectors, and the second passage to which the suction port of each ejector is connected is connected to the second passage for each ejector. An on-off valve is inserted and provided.

  According to a ninth aspect of the present invention, in the eighth aspect, the plurality of ejectors are arranged in series with each other, and a subsequent application port is connected to the front discharge port.

  In a tenth aspect of the present invention based on the eighth aspect, the plurality of ejectors are arranged in parallel to each other, and adjacent discharge ports and application ports are connected to each other.

  In an eleventh aspect of the present invention, in any one of the second to tenth aspects of the present invention, at least one of the on-off valve and the check valve is coupled and integrated with the ejector.

  According to the present invention, the purge valve for controlling the purge flow rate is provided in the first passage, and no purge valve is provided in the second passage for purging the canister using the negative pressure generated by the ejector. Therefore, when purging through the second passage, it is not affected by the pressure loss of the purge valve, and the necessary purge flow rate can flow even if the negative pressure generated by the ejector is weak. Even if an on-off valve or a check valve may be provided in the second passage, these valves simply open and close, and the pressure loss is smaller than that of the purge valve. can do.

It is a system configuration figure in a 1st embodiment of the present invention. It is a system configuration figure in a 2nd embodiment of the present invention. It is a system configuration figure in a 3rd embodiment of the present invention. It is a system configuration figure in a 4th embodiment of the present invention. It is a system configuration figure in a 5th embodiment of the present invention. It is an expanded sectional view of the VI section of FIG. It is an expanded sectional view similar to FIG. 6 in 6th Embodiment of this invention. It is a system configuration figure in a 7th embodiment of the present invention. It is an expanded sectional view of the IX part of FIG. It is an expanded sectional view similar to FIG. 9 in 8th Embodiment of this invention. It is an expanded sectional view of the ejector in 9th Embodiment of this invention. It is an expanded sectional view similar to FIG. 11 in 10th Embodiment of this invention. It is a system configuration figure in an 11th embodiment of the present invention. It is a system configuration figure in a 12th embodiment of the present invention.

<First embodiment>
FIG. 1 shows a first embodiment of the present invention. In this embodiment, the evaporated fuel processing apparatus 10 is added to an engine system 20 of a vehicle provided with a turbocharger 22 as a supercharger. In the following description, the expressions upstream and downstream are upstream and downstream with respect to the flow of air or evaporated fuel flowing through each part of the engine system 20 and the evaporated fuel processing apparatus 10.

  In FIG. 1, an engine system 20 is a well-known one, and an air-fuel mixture obtained by mixing fuel with air is supplied to an engine body (hereinafter also simply referred to as an engine) 21 through an air supply passage (hereinafter also referred to as an air supply pipe). Supply. An air cleaner 25, a turbocharger 22, an intercooler 24, and a throttle valve 23 are provided in the air supply passage in order from the upstream side in the air flow. The amount of air to the engine 21 is controlled and supplied by the throttle valve 23, and the fuel is supplied by controlling the flow rate by the fuel injection valve 28. Both the throttle valve 23 and the fuel injection valve 28 are connected to a control circuit 26, and the throttle valve 23 supplies a signal related to the amount of opening of the throttle valve 23 to the control circuit 26, and the fuel injection valve 28 is opened by the control circuit 26. The valve time is controlled. Fuel is supplied to the fuel injection valve 28 from a fuel tank 27 via a fuel supply pipe (not shown). Although not shown, the control circuit 26 is supplied with a detection signal from a pressure sensor that detects the air pressure in the air supply passage on the downstream side of the throttle valve 23.

  The evaporated fuel processing apparatus 10 adsorbs fuel vapor generated during refueling or fuel vapor evaporated in the fuel tank 27 (hereinafter referred to as evaporated fuel) to the canister 11 via the vapor passage 16. Further, the evaporated fuel adsorbed by the canister 11 is supplied to the supply passage of the engine 21 via the purge passage 15 and purged. The purge passage 15 is branched into a first passage 15a and a second passage 15b on the downstream side of the canister 11, the first passage 15a is connected to an air supply passage on the downstream side of the throttle valve 23, and the second passage 15b is The turbocharger 22 is connected to an air supply passage on the upstream side of the compressor.

  A purge valve 12 is inserted into the first passage 15a. The purge valve 12 is controlled in response to a signal from the control circuit 26, and controls the flow rate of air flowing through the first passage 15a. On the other hand, a known ejector 13 is inserted into the second passage 15b. As is well known, the ejector 13 includes an application port 13a that receives pressurized air, a suction port 13c that sucks external air by the negative pressure generated in the ejector 13, and air that has entered from the application port 13a and the suction port 13c. A discharge port 13b for discharging outside the ejector 13 is provided. The application port 13a is connected to an air supply passage on the downstream side of the compressor of the turbocharger 22 through an application passage 13d, and the suction port 13c and the discharge port 13b are inserted and connected to the second passage 15b. Therefore, the suction port 13c is connected to the canister 11 side, and the discharge port 13b is connected to the air supply passage side. A check valve 14 is inserted and provided upstream of the suction port 13c of the ejector 13 in the second passage 15b. The check valve 14 allows air to flow to the first passage 15a through the second passage 15b. It is configured to block.

  During the operation of the engine 21, the control circuit 26 executes the feedback control of the air-fuel ratio of the engine 21. When the purge of the canister 11 is permitted, the purge is performed through the purge passage 15. At this time, if the supercharging pressure by the turbocharger 22 is not sufficiently high, no negative pressure is generated at the suction port 13c of the ejector 13, and therefore the canister 11 is not purged through the second passage 15b, but the first passage 15a. Done through. The purge flow rate at this time is controlled by the purge valve 12. Since the check valve 14 is provided in the second passage 15b, when purging is performed through the first passage 15a, the flow of air to the first passage 15a through the second passage 15b is prevented.

  When the supercharging pressure by the turbocharger 22 becomes sufficiently high, supercharging air flows from the application port 13a of the ejector 13 to the discharge port 13b through the application passage 13d, and a predetermined negative pressure is generated at the suction port 13c of the ejector 13. Therefore, the canister 11 is purged through the second passage 15b. At this time, since the pressure on the downstream side of the throttle valve 23 is made higher than the atmospheric pressure by the supercharging pressure, the purge through the first passage 15a is not performed.

  As described above, the purge flow when purging through the second passage 15 b based on the negative pressure generated by the ejector 13 passes through the check valve 14 but does not pass through the purge valve 12. Since the purge valve 12 needs to improve the response of the control of the purge amount, the valve opening amount is restricted and the pressure loss becomes relatively large. On the other hand, since the check valve 14 does not have such a restriction, the pressure loss is relatively small. Therefore, compared with the case where the purge valve 12 is inserted in the second passage 15b, the pressure loss in the second passage 15b is reduced, and the necessary purge can be performed even if the negative pressure generated by the ejector 13 is weak. it can.

  Incidentally, since the purge valve 12 is not inserted into the second passage 15b, the purge flow rate cannot be controlled. However, the purge through the second passage 15b is performed when the supercharging pressure by the turbocharger 22 is sufficiently high, and the amount of air supplied to the engine 21 is large. For this reason, even if the purge flow rate is not controlled through the second passage 15b, the air-fuel ratio is not adversely affected.

<Second Embodiment>
FIG. 2 shows a second embodiment of the present invention. A feature of the second embodiment over the first embodiment (see FIG. 1) is that the check valve 14 in the first embodiment is replaced with a solenoid valve (corresponding to the on-off valve of the present invention) 17. is there. The other points are the same, and the repetitive description of the same part is omitted. The solenoid valve 17 receives a signal from the control circuit 26 and is controlled to open and close according to the operating state of the engine 21 and the evaporated fuel concentration adsorbed to the canister 11, and the purge flow rate through the second passage 15b is intermittent. Control is possible.

  As described above, in the first embodiment, when the purge through the second passage 15b is performed, the purge flow rate cannot be controlled, but in the second embodiment, the opening / closing control of the electromagnetic valve 17 is performed. The control of the purge flow rate through the second passage 15b can be performed roughly as compared with the control by the purge valve 12.

<Third embodiment>
FIG. 3 shows a third embodiment of the present invention. A feature of the third embodiment over the first embodiment (see FIG. 1) is that an electromagnetic valve 17 is inserted downstream of the ejector 13 in the second passage 15b. The other points are the same, and the repetitive description of the same part is omitted. The solenoid valve 17 in the third embodiment is exactly the same as the solenoid valve 17 in the second embodiment described above, and has the same function.

  The electromagnetic valve 17 in the second embodiment is provided on the upstream side of the ejector 13 in the second passage 15b to control the purge flow flowing through the second passage 15b, whereas the electromagnetic valve 17 in the third embodiment is Provided on the downstream side of the ejector 13 in the second passage 15b, the purge flow flowing through the second passage 15b is controlled. Although there is no difference between the two in terms of function, in the third embodiment, when the solenoid valve 17 is closed, the supercharged air does not flow to the ejector 13, so that the wasteful operation of the turbocharger 22 is suppressed. In the third embodiment, a check valve 14 is inserted and provided on the upstream side of the ejector 13 in the second passage 15b. This is to prevent air from flowing to the first passage 15a through the application passage 13d and the second passage 15b when purging is performed through the first passage 15a. In the case of the third embodiment, the insertion position of the check valve 14 may be changed to the application passage 13d instead of the second passage 15b.

<Fourth embodiment>
FIG. 4 shows a fourth embodiment of the present invention. A feature of the fourth embodiment over the first embodiment (see FIG. 1) is that an electromagnetic valve 17 is inserted into the application passage 13d. The other points are the same, and the repetitive description of the same part is omitted. The solenoid valve 17 in the fourth embodiment is exactly the same as the solenoid valve 17 in the second embodiment described above, and the function thereof is also the same.

  By controlling the opening and closing of the solenoid valve 17 of the fourth embodiment, it is possible to control the purge through the second passage 15b. This is the same as in the second and third embodiments described above, but in the fourth embodiment, when the solenoid valve 17 is closed, the supercharged air does not flow to the ejector 13 and the turbocharger 22 is wasted. Operation is suppressed. Further, when purging through the second passage 15b, the electromagnetic valve 17 does not exist in the second passage 15b, so that pressure loss in the second passage 15b can be suppressed.

<Fifth embodiment>
FIG. 5 shows a fifth embodiment of the present invention. The feature of the fifth embodiment over the second embodiment (see FIG. 2) is that the electromagnetic valve 17 is coupled to the ejector 13 and integrated. The other points are the same, and the repetitive description of the same part is omitted.

  FIG. 6 shows an integrated solenoid valve 17 and ejector 13 of the fifth embodiment. The suction port 13c of the ejector 13 is inserted into the second port 17b of the electromagnetic valve 17 so that both are coupled. The solenoid valve 17 is closed when the valve body 172 is in contact with the valve seat 173, and is opened when the valve body 172 is separated from the valve seat 173. The valve body 172 always contacts the valve seat 173 by the urging force of the spring 177 to close the electromagnetic valve 17. When the electromagnetic coil 171 is energized by the control circuit 26 through the connector 176, the plunger 174 embedded in the valve body 172 and integrated with the plunger 174 is attracted to the fixed core 175 magnetized by the electromagnetic coil 171, and the valve body 172 leaves the valve seat 173 to open the solenoid valve 17. In the valve open state, the first port 17a and the second port 17b communicate with each other, and thus the second passage 15b communicates (see FIG. 5).

  According to the fifth embodiment, since the solenoid valve 17 and the ejector 13 are integrated without being dispersedly arranged, the configuration as a system can be simplified and the system can be downsized.

<Sixth embodiment>
FIG. 7 shows the solenoid valve 17 and the ejector 13 in the sixth embodiment of the present invention. A feature of the sixth embodiment over the fourth embodiment (see FIG. 4) is that the electromagnetic valve 17 is coupled to the ejector 13 and integrated. The other points are the same, and the repetitive description of the same part is omitted. By inserting the application port 13 a of the ejector 13 into the second port 17 b of the electromagnetic valve 17, both are coupled. The configuration of the electromagnetic valve 17 is the same as that described with reference to FIG. 6, and when the electromagnetic valve 17 is opened, the first port 17a and the second port 17b communicate with each other. The application passage 13d is communicated (see FIG. 4). As described above, in the sixth embodiment, similarly to the fifth embodiment (see FIG. 5), the electromagnetic valve 17 and the ejector 13 are integrated, so that the configuration as a system can be simplified and the system can be downsized. can do.

<Seventh embodiment>
FIG. 8 shows a seventh embodiment of the present invention. A feature of the seventh embodiment over the fifth embodiment (see FIG. 5) is that a diaphragm valve 18 (corresponding to the on-off valve of the present invention) is employed instead of the electromagnetic valve 17 in the fifth embodiment. It is. The other points are the same, and the repetitive description of the same part is omitted.

  FIG. 9 shows an integrated diaphragm valve 18 and ejector 13 according to the seventh embodiment. The suction port 13c of the ejector 13 is inserted into the first port 18a of the diaphragm valve 18 so that both are coupled. The diaphragm valve 18 is closed when the valve body 182 is in contact with the valve seat 183, and is opened when the valve body 182 is separated from the valve seat 183. The valve body 182 always abuts against the valve seat 183 by the urging force of the spring 185 to close the diaphragm valve 18. When supercharged air having a pressure higher than a predetermined pressure is introduced from the turbocharger 22 through the third port 18 c into the pressure sensing chamber 184 partitioned by the diaphragm 181, the diaphragm 181 is deformed by the pressure, and the valve body 182. Is separated from the valve seat 183 to open the diaphragm valve 18. In the valve open state, the first port 18a and the second port 18b communicate with each other, and therefore the second passage 15b communicates (see FIG. 8).

  According to the seventh embodiment, the diaphragm valve 18 is purged through the second passage 15b when the supercharging pressure from the turbocharger 22 is higher than a predetermined pressure. Therefore, control of the purge flow rate by the second passage 15b cannot be performed regardless of the supercharging pressure generated by the turbocharger 22, but purging is performed through the second passage 15b while the supercharging pressure is lower than the predetermined pressure. Instead, it can be controlled to perform the purge through the second passage 15b in a state where the pressure is higher than the predetermined pressure. In the seventh embodiment, since the diaphragm valve 18 and the ejector 13 are integrated, the configuration as a system can be simplified, and the system can be downsized. In addition, the diaphragm valve 18 is controlled to open and close by air pressure, and there is an advantage that the power is not consumed unlike the electromagnetic valve 17.

<Eighth embodiment>
FIG. 10 shows an eighth embodiment of the present invention. A feature of the eighth embodiment over the sixth embodiment (see FIG. 7) is that a diaphragm valve 18 is employed instead of the electromagnetic valve 17 in the sixth embodiment. The other points are the same, and the repetitive description of the same part is omitted. By inserting the application port 13 a of the ejector 13 into the second port 18 b of the diaphragm valve 18, both are combined and integrated. The configuration of the diaphragm valve 18 is the same as that described with reference to FIG. 9, and when the diaphragm valve 18 is opened, the first port 18a and the second port 18b communicate with each other. The application passage 13d is communicated (see FIG. 4). As described above, also in the eighth embodiment, since the diaphragm valve 18 and the ejector 13 are integrated, the configuration as a system can be simplified, and the system can be downsized. Further, the diaphragm valve 18 is controlled to be opened and closed by air pressure, and has an advantage of not consuming electric power unlike the electromagnetic valve 17.
<Ninth embodiment>
FIG. 11 shows a ninth embodiment of the present invention. A feature of the ninth embodiment over the third embodiment (see FIG. 3) is that the check valve 14 is coupled to the ejector 13 and integrated. The other points are the same, and the repetitive description of the same part is omitted.

  By inserting the suction port 13c of the ejector 13 into the second port 14b of the check valve 14, both are coupled and integrated. The check valve 14 is closed when the valve body 141 is in contact with the valve seat 143, and is opened when the valve body 141 is separated from the valve seat 143. The valve element 141 is normally in contact with the valve seat 143 by the biasing force of the spring 142 to close the check valve 14, and air pressure is applied from the first port 14 a of the check valve 14 to the tip of the valve element 141. When the pressure is large enough to bend the spring 142, the valve body 141 is separated from the valve seat 143 to open the check valve 14. In the opened state of the check valve 14, the first port 14a and the second port 14b are communicated with each other, and thus the second passage 15b is communicated (see FIG. 3).

  According to the ninth embodiment, since the check valve 14 and the ejector 13 are integrated without being dispersedly arranged, the configuration as a system can be simplified and the system can be downsized.

<Tenth embodiment>
FIG. 12 shows a tenth embodiment of the present invention. The feature of the tenth embodiment over the ninth embodiment (see FIG. 11) is that the check valve 14 is connected to the suction port 13c of the ejector 13 in the ninth embodiment, whereas the application of the ejector 13 is different. The check valve 14 is connected to the port 13a. The other points are the same, and the repetitive description of the same part is omitted. In the tenth embodiment, the application port 13a of the ejector 13 is inserted into the second port 14b of the check valve 14 so that both are coupled. The configuration of the check valve 14 is the same as that described with reference to FIG. 11. When the check valve 14 is opened, the first port 14a and the second port 14b communicate with each other. Therefore, the application passage 13d is communicated (see FIG. 3). Thus, also in the tenth embodiment, since the check valve 14 and the ejector 13 are integrated as in the ninth embodiment, the configuration as a system can be simplified and the system can be downsized. .

<Eleventh embodiment>
FIG. 13 shows an eleventh embodiment of the present invention. The feature of the eleventh embodiment over the second embodiment (see FIG. 2) is that the ejector 13 in the second embodiment is replaced with a multistage ejector 131. The other points are the same, and the repetitive description of the same part is omitted.

  The multi-stage ejector 131 in the eleventh embodiment is a known one, and three single ejectors are arranged in series. Specifically, the first-stage ejector 131A is disposed on the most upstream side in the flow of supercharged air, and the application port of the second-stage ejector 131B is coupled to the discharge port of the first-stage ejector 131A. The application port of the third-stage ejector 131C is coupled to the discharge port of the eye ejector 131B. The application port of the first stage ejector 131A is the application port 13a of the multistage ejector 131 and is connected to the downstream side of the turbocharger 22 in the air supply passage. The discharge port of the third stage ejector 131C is connected to the multistage ejector 131. The discharge port 13b is connected to the upstream side of the turbocharger 22 in the supply passage. The multistage ejector 131 has three suction ports 13c as the multistage ejector 131 corresponding to the suction ports of the first to third stage ejectors, and each suction port 13c communicates with the second passage 15b. Yes. An electromagnetic valve 17 is inserted and provided in each second passage 15b. The electromagnetic valve 17 in the eleventh embodiment is exactly the same as the electromagnetic valve 17 in the second embodiment described above, and the function thereof is also the same.

  According to the eleventh embodiment, three ejectors 131 are used to connect three ejectors in series, the second passages 15b are provided corresponding to the three ejectors, and the communication states of the respective second passages 15b are changed to the respective states. It can be controlled by the electromagnetic valve 17. Therefore, the operation of the three ejectors can be controlled by the combination of opening and closing of the electromagnetic valves 17 to control the purge flow rate more accurately than in the case of control using only one electromagnetic valve 17.

  In the eleventh embodiment, the multi-stage ejector 131 is used, but single function ejectors 13 may be directly connected to each other so as to exhibit the same function.

<Twelfth embodiment>
FIG. 14 shows a twelfth embodiment of the present invention. The feature of the twelfth embodiment over the eleventh embodiment (see FIG. 13) is that three independent ejectors 13 are connected in parallel and used in place of the multistage ejector 131 in the eleventh embodiment. It is. The other points are the same, and the repetitive description of the same part is omitted.

  In the twelfth embodiment, the application ports 13a of the three ejectors 13 are connected in parallel to each other and communicated with the application passage 13d. Further, the discharge ports 13b of the three ejectors 13 are connected in parallel to each other and communicated with the downstream portion of the second passage 15b. Further, the suction ports 13c of the three ejectors 13 are connected in parallel to each other and communicated with the upstream portion of the second passage 15b. An electromagnetic valve 17 is connected to each suction port 13c. The solenoid valve 17 in the twelfth embodiment is exactly the same as the solenoid valve 17 in the second embodiment described above, and the function thereof is also the same.

  According to the twelfth embodiment, three ejectors 13 connected to the second passage 15b are provided in parallel, and the communication state of each second passage 15b corresponding to each ejector 13 can be controlled by each solenoid valve 17. Therefore, the purge flow rate can be increased as a whole, and the operation of the three ejectors is controlled by the combination of opening and closing of the electromagnetic valves 17 to control the purge flow rate as compared with the case of control using only one electromagnetic valve 17. Can be done with high accuracy.

  As mentioned above, although specific embodiment was described, this invention is not limited to those external appearances and structures, A various change, addition, and deletion are possible in the range which does not change the summary of this invention. For example, in the above embodiment, the turbocharger 22 is a turbocharger, but may be a mechanical supercharger. In the eleventh and twelfth embodiments, an example in which three ejectors are used in combination has been shown. However, the number of ejectors to be combined may be two or four or more. Furthermore, in the above embodiment, the present invention is applied to an engine system for a vehicle, but the present invention is not limited to a vehicle. In the case of an engine system for a vehicle, a hybrid vehicle using both an engine and a motor may be used.

DESCRIPTION OF SYMBOLS 10 Evaporative fuel processing apparatus 11 Canister 12 Purge valve 13 Ejector 13a Application port 13b Discharge port 13c Suction port 13d Application passage 131 Multistage ejector 131A First stage ejector 131B Second stage ejector 131C Third stage ejector 14 Check valve 14a First port 14b Second port 141 Valve body 142 Spring 143 Valve seat 15 Purge passage 15a First passage 15b Second passage 16 Vapor passage 17 Solenoid valve (open / close valve)
17a 1st port 17b 2nd port 171 Electromagnetic coil 172 Valve body 173 Valve seat 174 Plunger 175 Fixed core 176 Connector 177 Spring 18 Diaphragm valve (open / close valve)
18a First port 18b Second port 18c Third port 181 Diaphragm 182 Valve body 183 Valve seat 184 Pressure sensing chamber 185 Spring 20 Engine system 21 Engine body (engine)
22 Turbocharger (supercharger)
23 Throttle valve 24 Intercooler 25 Air cleaner 26 Control circuit 27 Fuel tank 28 Fuel injection valve

Claims (11)

An evaporative fuel processing apparatus that is provided in an engine with a supercharger, adsorbs evaporated fuel in a fuel tank to a canister through a vapor passage, and sucks and purges the evaporated fuel adsorbed in the canister into the engine through a purge passage,
The purge passage is branched into a first passage and a second passage on the downstream side of the canister by a flow of evaporated fuel flowing through the purge passage, and the first passage is a throttle valve by a flow of supply air in an intake passage of the engine. The second passage is connected to the upstream side of the supercharger in the supply air flow in the supply passage,
An ejector for receiving a supercharge generated by the supercharger to generate a negative pressure, and an application port for receiving the supercharge from the supercharger in the ejector is a flow of the supply air to the engine. A discharge port connected to the downstream side of the supercharger and for discharging supercharged air flowing into the application port in the ejector is inserted into the second passage together with a suction port for generating negative pressure in the ejector. The suction port is connected to the canister side, and the discharge port is connected to the air supply passage side,
An evaporative fuel processing apparatus for an engine with a supercharger, wherein the first passage is provided with a purge valve for controlling a flow rate flowing through the first passage. In claim 1,
An evaporative fuel processing device for an engine with a supercharger, comprising an on-off valve that intermittently controls an air flow flowing through the second passage. In claim 2,
The on-off valve is an evaporative fuel processing device for a supercharged engine provided by being inserted into the second passage. In claim 2,
The on-off valve is an evaporative fuel processing device for an engine with a supercharger, wherein the application port of the ejector is inserted into an application passage connected to the downstream side of the supercharger. In any of claims 2 to 4,
The on-off valve is an evaporated fuel processing device for a supercharged engine, which is an electromagnetic valve that is opened and closed by an electric signal. In any of claims 2 to 4,
The on-off valve receives a supercharged air generated by the supercharger, and is a diaphragm valve that opens when the air pressure is higher than a predetermined pressure and closes when the air pressure is low. In any one of Claims 2 thru | or 6.
An evaporative fuel processing apparatus for an engine with a supercharger, comprising a check valve that prevents air from flowing through the second passage to the first passage. In any one of Claims 1 thru | or 7,
The ejector is composed of a plurality of ejectors, and the second passage to which the suction port of each ejector is connected is provided with the on-off valve inserted for each ejector. apparatus. In claim 8,
The plurality of ejectors are arranged in series with each other, and an evaporative fuel processing apparatus for a supercharged engine in which a subsequent application port is connected to a front discharge port. In claim 8,
The plurality of ejectors are arranged in parallel with each other, and the adjacent fuel discharge ports and the application ports are connected to each other. In any of claims 2 to 10,
At least one of the on-off valve and the check valve is an evaporative fuel processing device for a supercharged engine in which the ejector is coupled and integrated.

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