JP5949150B2 - Evaporative fuel purge device - Google Patents

Description

  The present invention relates to an evaporated fuel purge apparatus that purges evaporated fuel into an engine including a supercharger.

  As a conventional evaporative fuel purge apparatus, for example, the one disclosed in Patent Document 1 is known. The evaporated fuel purge device of Patent Literature 1 (evaporated fuel processing device in Patent Literature 1) is provided to supply evaporated fuel to an engine equipped with a supercharger. In the case where the supercharger is not operating, the intake manifold has a negative pressure due to the suction action of the piston, and the main purge control valve is opened to evaporate in the fuel tank and adsorb in the canister. Fuel is drawn into the intake manifold.

  Further, when the supercharger is activated and the intake manifold has a positive pressure, the compressed air is stored in the pressure accumulation tank on the downstream side of the supercharger, and the compressed air is sent from the pressure accumulation tank to the ejector. . The evaporated fuel is sucked by the suction action of the ejector, and the main purge control valve is opened to be supplied into the intake manifold.

  As described above, the evaporative fuel purging device of the cited document 1 is directed to the upstream side of the supercharger even if the intake manifold becomes positive pressure with the operation of the supercharger with respect to the engine provided with the supercharger. It is possible to supply evaporative fuel.

JP 2008-38808 A

  However, when the fuel vapor purge device is to be directly mounted on the intake manifold, it is necessary to integrally provide the main purge control valve and the ejector. Here, if the main flow direction of the ejector is the same as the direction of the main flow path of the evaporated fuel passing through the main purge control valve, the ejector and the intake air can be connected in order to connect the ejector to the supercharger. It is necessary to increase the distance from the manifold, and the evaporative fuel purge device is poorly mountable.

  In view of the above problems, an object of the present invention is to supply evaporative fuel to an engine equipped with a supercharger. Even when a control valve and an ejector are provided integrally, the mountability to an intake manifold is improved. It is an object of the present invention to provide an evaporative fuel purging apparatus excellent in the above.

  In order to achieve the above object, the present invention employs the following technical means.

In the invention according to claim 1, in the evaporated fuel purge device for purging the evaporated fuel generated in the fuel tank (60) to the engine including the supercharger (40),
A main flow path (130) formed in a crank shape inside the main body (110), and for allowing the evaporated fuel to flow from the fuel tank (60) side to the intake portion (10) side of the engine;
A valve (150) that is an electromagnetic valve disposed in a region where the direction of the crank-shaped main flow path (130) changes direction inside the main body and opens and closes the main flow path (130);
A branch channel (160) branched from the downstream side of the valve (150) of the main channel (130);
A part of the intake air on the downstream side of the supercharger (40) flows in, a part of the intake air flows out to the upstream side of the supercharger (40), and a suction part (182) that exhibits a suction function by the flow of intake air ) to the ejector branch passages (160) is connected (180), but are formed integrally,
The flow direction of the intake air in the ejector (180) is arranged in a direction intersecting with the main direction of the main flow path (130).

  In the present invention, when the valve (150) is opened when the supercharger (40) is not operating, the evaporated fuel is discharged from the fuel tank (60) to the main flow path (by the negative pressure in the suction portion (10)). 130), flows through the valve (150) and is sucked into the suction part (10).

  Further, when the supercharger (40) is operating, the suction portion (10) has a positive pressure and it becomes difficult to suck the evaporated fuel as described above. Here, however, the ejector (180) ), And when the valve (150) is opened, the evaporative fuel is drawn from the fuel tank (60) to the main flow path (by the suction action (182) of the ejector (180)). 130), the valve (150), the branch flow path (160), the suction part (182) sucks into the ejector (180), and the upstream side of the supercharger (40) together with the intake air flowing through the ejector (180). To be supplied.

  Thus, even if this evaporative fuel purge apparatus (100) is an engine provided with a supercharger (40), evaporative fuel is supplied to the suction part (10) or the upstream side of the supercharger (40). be able to.

  In the fuel vapor purge apparatus (100), a main channel (130), a valve (150), a branch channel (160), and an ejector (180) are integrally formed. Further, since the flow direction of the intake air in the ejector (180) is arranged in a direction intersecting with the main direction of the main flow path (130), the evaporated fuel purge device (100) is connected to the intake portion ( In the case of mounting directly to 10), the end of the ejector (180) in the intake flow direction can be provided at a position apart from the suction portion (10) without being close to the suction portion (10). It becomes possible to easily connect the feeder (40). Therefore, it can be set as the evaporative fuel purge apparatus (100) excellent in mountability with respect to the suction part (10).

  In addition, the code | symbol in the bracket | parenthesis of each said means shows a corresponding relationship with the specific means of embodiment description mentioned later.

1 is an overall schematic diagram showing an engine intake system, an evaporated fuel purge system, and an evaporated fuel purge device. It is a perspective view which shows the external appearance of an evaporative fuel purge apparatus. It is a three-dimensional sectional view showing the internal structure of the evaporated fuel purge device. It is sectional drawing which shows an ejector. It is the arrow view seen from the V direction of FIG.

  A plurality of modes for carrying out the present invention will be described below with reference to the drawings. In each embodiment, parts corresponding to the matters described in the preceding embodiment may be denoted by the same reference numerals, and redundant description may be omitted. When only a part of the configuration is described in each mode, the other modes described above can be applied to the other parts of the configuration. Not only combinations of parts that clearly indicate that the combination is possible in each embodiment, but also a combination of the embodiments even if they are not clearly specified unless there is a problem with the combination. It is also possible.

(First embodiment)
An evaporated fuel purge apparatus 100 according to a first embodiment of the present invention will be described with reference to FIGS. The evaporated fuel purge apparatus 100 introduces (purifies) evaporated fuel into the intake system 1 of the engine in order to prevent the evaporated fuel generated in the fuel tank 60 from being released into the atmosphere during refueling. It is. The evaporated fuel introduced into the engine intake system 1 is mixed with combustion fuel supplied to the engine from an injector (not shown) or the like and burned in the cylinder of the engine. The evaporated fuel purge apparatus 100 is connected to an engine intake system 1 and an evaporated fuel purge system 2.

  As shown in FIG. 1, an intake system 1 of an engine has an intake pipe 20 connected to an intake manifold 10 of an engine that is an internal combustion engine. Further, a filter 30, a supercharger 40, an intercooler 50, a throttle are connected to the intake pipe 20. A valve 11 and the like are provided and formed. The intake manifold 10 corresponds to the intake portion of the present invention.

  The filter 30 is disposed at the most upstream portion of the intake pipe 20 and captures dust, dust, and the like in the intake air. The supercharger 40 is an intake compressor for increasing the charging efficiency of intake air, and is disposed on the downstream side of the filter 30. In the supercharger 40, the turbine is operated by the exhaust energy of the engine, and the intake air that has passed through the filter 30 is pressurized by a compressor that is linked to the turbine. The intercooler 50 is a heat exchanger for cooling, and is disposed on the downstream side of the supercharger 40. The intercooler 50 performs heat exchange between the intake air pressurized by the supercharger 40 and, for example, outside air, and cools (air-cools) the intake air. The throttle valve 11 is an intake air amount adjustment valve, and adjusts the amount of intake air flowing into the intake manifold 10 by adjusting the opening at the inlet of the intake manifold 10 in conjunction with the accelerator pedal. . The intake air passes through the devices 30, 40, 50, and 11 and flows into the intake manifold 10 and is mixed with combustion fuel injected from an injector or the like so as to have a predetermined air-fuel ratio. Burned.

  A portion of the intake pipe 20 downstream of the supercharger 40, that is, between the supercharger 40 and the intercooler 50, or between the intercooler 50 and the throttle valve 11, is an intake air flow of the evaporated fuel purge device 100. A pipe 191 is connected. Further, an upstream side of the supercharger 40 in the intake pipe 20, that is, a portion between the filter 30 and the supercharger 40 is connected to the intake / outflow pipe 192 of the evaporated fuel purge apparatus 100.

  The evaporative fuel purge system 2 is formed by sequentially connecting a fuel tank 60, a pipe 61, a canister 70, a pipe 71, and an evaporative fuel purge apparatus 100. The evaporated fuel purge apparatus 100 is directly attached (direct mount) to the intake manifold 10 via an attachment portion 101 formed integrally with the main body portion 110.

  The fuel tank 60 is a container for storing fuel such as gasoline. The fuel tank 60 is connected to the inflow portion 70 a of the canister 70 by a pipe 61. The canister 70 is a container in which an adsorbent such as activated carbon is enclosed. The canister 70 takes in evaporated fuel generated in the fuel tank 60 from the inflow portion 70a via the pipe 61 and temporarily adsorbs the adsorbent on the adsorbent. It has become. The canister 70 is provided with a suction portion 70b for sucking fresh fresh air, and the evaporated fuel adsorbed on the adsorbent by the sucked fresh air is easily separated. . By forming the suction part 70 b in the canister 70, atmospheric pressure acts in the canister 70.

  The canister 70 is provided with an outflow portion 70c through which the evaporated fuel separated from the adsorbent flows out. One end side of the pipe 71 is connected to the outflow portion 70 c, and the other end side is connected to the fuel inflow pipe 121 of the evaporated fuel purge apparatus 100. The fuel outflow pipe 122 of the evaporated fuel purge apparatus 100 is connected to the inflow portion of the intake manifold 10. The axial direction of the fuel outflow pipe 122 is a direction that intersects, for example, a direction orthogonal to the flow direction of the intake air in the intake manifold 10.

  As shown in FIGS. 2 and 3, the evaporated fuel purge apparatus 100 includes a fuel inflow pipe 121 and a fuel outflow pipe 122 protruding from the main body 110, a main flow path 130 provided in the main body 110, a filter 140, and a valve. 150, a branch flow path 160, a first check valve 171, a second check valve 172, and an ejector 180 including an intake inflow pipe 191 and an intake outflow pipe 192. The above-mentioned members of the evaporated fuel purge apparatus 100 are integrally formed.

  The fuel inflow pipe 121 is a fuel inflow channel that allows the evaporated fuel flowing out from the canister 70 to flow into the main body 110 (hereinafter, a main channel 130, a branch channel 160, and an ejector 180, which will be described in detail). 110 is provided on one end side.

  The fuel outflow pipe 122 is a fuel outflow passage through which the evaporated fuel flowing through the main passage 130 in the main body 110 flows out to the outside, and is provided on the other end side of the main body 110. The axial direction of the fuel outflow pipe 122 is the same as the axial direction of the fuel inflow pipe 121, but the positions of both axial centers are shifted. That is, the fuel outflow pipe 122 is arranged so as to be parallel to the fuel inflow pipe 121.

  The main flow path 130 is formed as a flow path that connects the fuel inflow pipe 121 and the fuel outflow pipe 122 in the main body 110 and distributes the evaporated fuel. The main flow path 130 further includes a first flow path 131 that extends along the longitudinal direction of the fuel inflow pipe 121, a second flow path 132 that extends in a direction intersecting the first flow path 131, and the second flow path 132. The third flow path 133 is formed in the same direction as the first flow path 131 and extends toward the fuel outflow pipe 122. The main flow path 130 is actually formed in a crank shape by the first to third flow paths 131 to 133, but the main flow direction (main direction in the present invention) in the main flow path 130 is the fuel inflow pipe 121. The direction is the first flow path 131 and the third flow path 133 (axis A in FIG. 2) from the side (fuel tank 60 side) to the fuel outflow pipe 122 side (intake manifold 10 side).

  The filter 140 captures dust, dust, and the like in the evaporated fuel, and is disposed in the middle of the second flow path 132. The filter 140 is formed from, for example, a mesh member having a fine mesh shape.

  The valve 150 is an opening / closing means that opens and closes the main flow path 130, and is disposed in the middle of the main flow path 130. Here, the valve 150 is provided in a region where the second flow path 132 changes to the third flow path 133 on the downstream side of the filter 140. As the valve 150, an electromagnetic valve provided with a valve body 151, an electromagnetic coil 152, and a spring (not shown) is used. The valve 150 opens and closes the main flow path 130 by a balance between the electromagnetic force when the electromagnetic coil 152 is energized through the connector 153 and the elastic force of the spring by a control unit (not shown).

  The valve 150 normally maintains a state in which the main flow path 130 is closed, and when the electromagnetic coil 152 is energized by the control unit, the electromagnetic force overcomes the elastic force of the spring and opens the main flow path 130. It is supposed to be. The control unit circulates in the main flow path 130 by energizing the electromagnetic coil 152 by adjusting the ratio of the on time to the time of one cycle formed by the energization on time and the off time, that is, the duty ratio. The flow rate of the evaporated fuel can be adjusted.

  The branch flow path 160 is a flow path that branches from the downstream side of the valve 150 of the main flow path 130, that is, from the middle portion of the third flow path 133. The branch flow path 160 extends in a direction intersecting the third flow path 133, and the downstream side thereof is connected to a suction portion 182 of an ejector 180 described later.

  The first check valve 171 is a valve disposed in the main channel 130 on the downstream side of the branch point where the branch channel 160 branches. Specifically, the first check valve 171 is disposed between the branch point where the branch flow path 160 branches and the fuel outflow pipe 122 (third flow path 133). The first check valve 171 allows the original flow of the evaporated fuel from the fuel inflow pipe 121 to the fuel outflow pipe 122 in the main flow path 130 and the reverse flow of the evaporated fuel from the fuel outflow pipe 122 to the fuel inflow pipe 121. Is supposed to prevent. As the first check valve 171, for example, a valve body is used that has a bowl shape, opens the flow path with the original flow of the evaporated fuel, and closes the flow path with the reverse flow of the evaporated fuel.

  The second check valve 172 is a valve disposed in the branch flow path 160. The second check valve 172 allows the original flow of the evaporated fuel from the fuel inflow pipe 121 to the branch flow path 160, the suction part 182, and further to the intake / outflow pipe 192 in the branch flow path 160 and the suction part 182. The reverse flow of intake air from the intake side (intake inflow pipe 191 or intake outflow pipe 192 side) to the intake portion 10 side of the engine is prevented. Similar to the first check valve 171, the second check valve 172 has, for example, a bowl shape, opens the flow path along with the original flow of the evaporated fuel, and flows along with the reverse flow of the evaporated fuel. A valve element is used to close the valve.

  The ejector 180 is a fuel pump for evaporative fuel. A part of the intake air pressurized from the downstream side of the supercharger 40 flows into the inside, and a part of the intake air flows out to the upstream side of the supercharger 40. In addition, the evaporated fuel is sucked by the negative pressure formed when a part of the intake air flows inside. As shown in FIG. 4, the ejector 180 includes a nozzle part 181, a suction part 182, and a diffuser part 183.

  The nozzle portion 181 is a flow path that forms a throttle portion with respect to inflowing intake air, one end side is connected to the intake inflow pipe 191, and the other end side (front end side) extends toward the intake outflow pipe 192. Yes. The inner diameter of the nozzle portion 181 is formed so as to gradually decrease toward the tip. The nozzle portion 181 increases the flow velocity of the intake air that has flowed from the intake air inflow pipe 191 due to a throttling effect. Therefore, the region where the intake air flows out at a high speed on the tip side of the nozzle portion 181 has a negative pressure.

  The suction part 182 is a flow path extending in a direction intersecting the nozzle part 181, and is connected to communicate with the tip side of the nozzle part 181. The suction part 182 is connected to the branch flow path 160 (downstream of the second check valve 172), and sucks the evaporated fuel in the branch flow path 160 by the negative pressure of the nozzle part 181.

  The diffuser portion 183 is a flow path that gradually expands the inner diameter on the downstream side of the nozzle portion 181 and the suction portion 182 and extends to the intake / outflow pipe 192 side, and one end side communicates with the nozzle portion 181 and the suction portion 182. The other end that is enlarged is connected to the intake / outflow pipe 192. The diffuser portion 183 increases the pressure while decreasing the flow velocity of the intake air and the evaporated fuel flowing through the inside.

  The intake air inflow pipe 191 is an intake air inflow passage through which a part of the intake air pressurized by the supercharger 40 flows into the ejector 180). Further, the intake / outflow pipe 192 is an intake / outflow passage through which the intake air flowing through the ejector 180 flows out.

  In the ejector 180 described above, the flow direction of the intake air flowing through the ejector 180 (the axis B in FIG. 2) with respect to the main body 110 is the main flow direction (in FIG. It is arranged so as to be in a direction intersecting the axis A), for example, a direction orthogonal to it. Therefore, the axial direction of the intake inflow pipe 191 and the intake outflow pipe 192 of the ejector 180 is the direction intersecting the axial direction of the fuel inflow pipe 121 and the fuel outflow pipe 122 of the main body 110 (for example, the orthogonal direction). It has become.

  Further, as shown in FIG. 5, the ejector 180 is disposed so as to be located on the opposite side of the projecting direction of the fuel outflow pipe 122 with respect to the position of the projecting surface 111 from which the fuel outflow pipe 122 projects from the main body 110. Has been. In other words, the ejector 180 is not arranged in the region on the fuel outlet pipe 122 side beyond the protruding surface 111.

  Next, the operation of the evaporated fuel purge apparatus 100 based on the above configuration will be described. The evaporative fuel purge apparatus 100 performs a “normal purge” when the supercharger 40 is not operated and a “supercharge purge” when the supercharger 40 is operated.

1. Normal purge When the supercharger 40 is not operating when the vehicle is running, if the valve 150 is opened by a control unit (not shown), the negative pressure generated in the intake manifold 10 due to the intake action of the piston, the canister 70 The evaporated fuel adsorbed in the canister 70 due to the difference from the atmospheric pressure applied to the fuel flows into the fuel inflow pipe 121, the main flow path 130 (first flow path 131, second flow path 132), the valve 150, and the main flow path 130 (first flow path). 3 flow path 133), the first check valve 171 (open state), the main flow path 130 (third flow path 133), and the fuel outflow pipe 122, and sucked into the intake manifold 10 (broken line in FIG. 1) Arrow).

  The evaporated fuel sucked into the intake manifold 10 is mixed with the original combustion fuel supplied from the injector or the like to the engine and burned in the engine cylinder.

  In the engine cylinder, the air-fuel ratio, which is the mixing ratio of the combustion fuel and the intake air, is controlled so as to become a predetermined air-fuel ratio. The controller controls the opening / closing time of the valve 150 to adjust the purge amount of the evaporated fuel so that the predetermined air-fuel ratio is maintained even if the evaporated fuel is purged.

  Here, a second check valve 172 is provided in the branch flow path 160. Therefore, intake air tends to flow from the suction unit 182 side to the intake manifold 10 side from the downstream side of the supercharger 40 through the intake air inflow pipe 191 or from the upstream side of the supercharger 40 through the intake air outflow pipe 192. However, since the second check valve 172 is closed, the backflow of the intake air is prevented.

2. Purging at the time of supercharging When the supercharger 40 is operating when the vehicle is running, the intake manifold 10 becomes positive pressure due to the pressurized intake air, so it is difficult to suck the evaporated fuel as described above. It becomes. In the supercharging purge, a part of the intake air supercharged by the supercharger 40 circulates in the ejector 180 from the intake air inflow pipe 191 and returns to the upstream side of the supercharger 40 from the intake air outflow pipe 192 ( Solid line arrow in FIG. 1).

  At this time, when the valve 150 is opened by the control unit, the evaporated fuel adsorbed in the canister 70 by the suction action of the suction unit 182 of the ejector 180 flows into the fuel inflow pipe 121, the main channel 130 (the first channel 131, The second flow path 132), the valve 150, the main flow path 130 (third flow path 133), the branch flow path 160, and the second check valve 172 (open state) are sucked from the suction portion 182 to the ejector 180, and the ejector Along with the intake air flowing through 180, the air is supplied from the intake / outflow pipe 192 to the upstream side of the supercharger 40 (broken arrow in FIG. 1).

  The intake air and the evaporated fuel supplied to the upstream side of the supercharger 40 reach the intake manifold 10 via the intake pipe 20 and are mixed with the original combustion fuel supplied to the engine from an injector or the like. It is burned in the engine cylinder.

  Also in this case, the control unit adjusts the purge amount of the evaporated fuel so that the predetermined air-fuel ratio is maintained even if the evaporated fuel is purged to the intake pipe 20 by duty-controlling the opening / closing time of the valve 150. It is supposed to be.

  Here, a first check valve 171 is provided in the main channel 130. Therefore, even if the evaporated fuel tries to flow backward to the fuel tank 60 side from the intake manifold 10 side, which is positive pressure by the supercharger 40, to the fuel tank 60 side, the first check valve 171 is closed. Backflow will be prevented.

  As described above, in the evaporated fuel purge apparatus 100, even in an engine including the supercharger 40, the evaporated fuel can be supplied to the intake manifold 10 or the upstream side of the supercharger 40.

  In this embodiment, in the fuel vapor purge apparatus 100, the main flow path 130, the valve 150, the branch flow path 160, and the ejector 180 are integrally formed. Further, since the flow direction of the intake air in the ejector 180 is arranged in a direction intersecting the main direction of the main flow path 130, the evaporated fuel purge device 100 is directly mounted on the intake manifold 10 of the engine. In this case, the end of the ejector 180 in the intake flow direction can be provided at a position away from the intake manifold 10 without being close to the intake manifold 10, so that the ejector 180 and the supercharger 40 can be easily connected. . Therefore, it is possible to provide the evaporated fuel purge apparatus 100 that is excellent in mountability with respect to the intake manifold 10.

  Further, the ejector 180 is arranged on the opposite side of the protruding surface 111 of the main body 110 from the direction in which the fuel outflow pipe 122 protrudes. Thereby, the ejector 180 is not arranged on the intake manifold 10 side with respect to the protruding surface 111, and the distance between the ejector 180 and the intake manifold 10 can be appropriately secured.

(Other embodiments)
In the first embodiment, the ejector 180 has a flow direction of the intake air flowing through the ejector 180 (axis B in FIG. 2) with respect to the main body 110. (Axis A in FIG. 2) is arranged so as to be in an intersecting direction, for example, an orthogonal direction, but this is not limiting, and the angle at which axis A and axis B intersect is practical. The top can be set in the range of 90 ° ± 30 °.

  Further, the inflow and outflow directions of the intake air in the ejector 180 are reversed by changing the arrangement of the nozzle portion 181, the diffuser portion 183, the intake inflow pipe 191 and the intake / outflow pipe 192 with respect to the first embodiment. You may make it become.

10 Intake manifold (engine intake)
DESCRIPTION OF SYMBOLS 40 Supercharger 60 Fuel tank 100 Evaporative fuel purge apparatus 110 Main-body part 111 Projection surface 122 Fuel outflow pipe (fuel outflow channel)
130 Main flow path 150 Valve 160 Branch flow path 180 Ejector 182 Suction part

Claims (3)

In an evaporative fuel purge apparatus that purges evaporative fuel generated in a fuel tank (60) to an engine including a supercharger (40),
A main flow path (130) that is formed in a crank shape inside the main body (110) and distributes the evaporated fuel from the fuel tank (60) side to the engine intake portion (10) side;
A valve (150) as an electromagnetic valve disposed in a region where the direction of the crank-shaped main flow path (130) changes direction inside the main body, and opens and closes the main flow path (130);
A branch channel (160) branched from the downstream side of the valve (150) of the main channel (130);
A part of the intake air on the downstream side of the supercharger (40) is made to flow in, a part of the intake air is made to flow out to the upstream side of the supercharger (40), and a suction function is exhibited by the flow of the intake air. And an ejector (180) in which the branch channel (160) is connected to the suction part (182) , are integrally formed,
The evaporative fuel purge device is characterized in that the flow direction of the intake air in the ejector (180) is arranged in a direction intersecting the main direction of the main flow path (130).   2. The evaporated fuel purge apparatus according to claim 1, wherein an angle at which the flow direction of the intake air intersects the main direction is 90 degrees ± 30 degrees. A fuel outflow passage (122) that protrudes from the main body (110) forming the main passage (130) and outflows the evaporated fuel;
The ejector (180) is opposite to the direction in which the fuel outflow channel (122) projects relative to the projecting surface (111) of the main body (110) from which the fuel outflow channel (122) projects. The evaporative fuel purging device according to claim 1 or 2, wherein the fuel vapor purging device is disposed in a position.

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