JP4807296B2 - Evaporative fuel processing equipment - Google Patents

Description

  The present invention relates to an evaporated fuel processing apparatus, and more particularly to an evaporated fuel processing apparatus having a purge pump for forcibly sending fuel vapor adhering to a canister into an engine intake passage.

  The evaporated fuel evaporated in the fuel tank adheres to the canister, is desorbed by the engine negative pressure, and is sucked into the engine intake passage and burned. However, when the throttle opening is fully open or the like, a negative pressure is hardly generated in the engine intake passage, so that the fuel adhering to the canister may not be drawn into the engine intake passage and burned.

Therefore, in the technology described in Patent Document 1, a purge pump is provided for sending fuel adhering to the canister into the engine intake passage, and the fuel adhering to the canister is forcibly purged into the engine intake passage during engine operation. ing. In addition, after the engine is stopped, the purge pump is rotated in the reverse direction so that fuel vapor in which residual fuel in the intake passage is generated is sent to and attached to the canister.
Japanese Patent Laid-Open No. 2003-42014

  However, in the technique described in Patent Document 1, the purge pump is always driven during engine operation. However, there is room for improvement in the control of the purge pump in consideration of the operation state of the engine.

  The present invention has been made to solve the above-described problems, and an object thereof is to improve purge efficiency and fuel efficiency.

In order to achieve the above object, the invention according to claim 1 is directed to detecting the fuel vapor from a detecting means for detecting a fuel consumable amount required by the internal combustion engine and a canister for adsorbing the fuel vapor generated in the fuel tank. A purge pump for purging the intake passage of the internal combustion engine, and the fuel vapor from the canister to the intake passage when the fuel consumable amount detected by the detection means is greater than or equal to a predetermined value; A control means for controlling a purge pump; and the consumable amount of fuel detected by the detection means is less than a predetermined value, and the concentration detected by a concentration detection means for detecting the concentration of hydrocarbons in the canister is a predetermined value. In the above case, a travel motor serving as a travel source so as to purge the fuel vapor into the intake passage of the internal combustion engine by the intake negative pressure of the internal combustion engine And output control means for controlling the output ratio of the fine internal combustion engine, and comprising: a.

According to the first aspect of the present invention, the detecting means detects the amount of fuel that can be consumed by the internal combustion engine. For example, the detection means can detect the fuel consumption possible amount required by the internal combustion engine by detecting the accelerator opening, the rotational speed of the internal combustion engine, the intake pressure of the internal combustion engine, and the like.

  The fuel vapor adsorbed on the canister is purged to the intake passage of the internal combustion engine by the purge pump.

  Then, the control means controls the purge pump so as to purge the fuel vapor from the canister to the intake passage of the internal combustion engine when the fuel consumption possible amount detected by the detection means is equal to or greater than a predetermined value.

  The control means controls the purge pump when the combustion consumable amount is equal to or greater than the predetermined value as described above, so that when the internal combustion engine needs fuel, the fuel vapor is purged into the intake passage, and is adsorbed to the canister. The fuel vapor can be efficiently purged, the fuel injected into the internal combustion engine can be reduced, and the fuel consumption can be improved.

  As in the invention described in claim 2, the control means has a fuel consumption amount detected by the detection means equal to or greater than a predetermined value, and the concentration detected by the concentration detection means for detecting the hydrocarbon concentration in the canister. The purge pump may be controlled when it is equal to or greater than a predetermined value. As a result, when the fuel vapor adsorbed on the canister needs to be purged, the purge can be performed, and the purge can be efficiently performed.

  Further, when the control means controls the purge pump to be driven as in the third aspect of the invention, when the concentration detected by the concentration detection means becomes less than a predetermined value, You may control to stop a drive. As a result, the purge pump drive time can be shortened while ensuring the purge amount.

The control means according to claim 2 or claim 3 is the control means according to claim 4, wherein the consumable amount of fuel detected by the detection means is a predetermined value or more and the concentration detected by the concentration detection means is predetermined. The purge pump may be controlled when the battery load detected by the load detection means for detecting the battery load is equal to or greater than a value and equal to or less than a predetermined value. At this time, as in the invention described in claim 5, the output control means causes the fuel vapor to be discharged from the internal combustion engine by the intake negative pressure of the internal combustion engine when the battery load detected by the battery load detection means exceeds a predetermined value. as purged into the intake passage, Unishi may by that controls the output ratio of the traction motor and an internal combustion engine as a driving source. Thus, it is possible to prevent the battery power for driving the purge pump from being insufficient in consideration of the battery load. Further, in this case, the output control means increases the output of the traveling motor and changes the output ratio so as to decrease the output of the internal combustion engine, thereby reducing the accelerator opening of the internal combustion engine and reducing the negative pressure in the intake passage. Therefore, the purge amount can be secured by purging the fuel vapor with the intake negative pressure of the internal combustion engine.

In the output control means, when the consumable amount of fuel detected by the detection means is less than a predetermined value and the concentration detected by the concentration detection means for detecting the concentration of hydrocarbons in the canister is greater than or equal to the predetermined value, the internal combustion engine The output ratio of the traveling motor and the internal combustion engine as the travel source is controlled so that the fuel vapor is purged into the intake passage of the internal combustion engine by the intake negative pressure of the engine . That is, when the fuel consumable amount is less than the predetermined value and the hydrocarbon concentration in the canister is equal to or higher than the predetermined value, the output ratio is changed so that the output of the traveling motor is increased and the output of the internal combustion engine is decreased. Thus, the accelerator opening of the internal combustion engine can be reduced and the negative pressure in the intake passage can be increased, so that the fuel vapor can be purged by the negative pressure in the intake passage.

In addition, the invention according to any one of claims 1 to 5 is based on the detection result of the concentration detecting means after executing the control by the control means or the output control means as in the invention according to claim 6. The control unit or the output control unit may further include a determination unit that determines whether the control is necessary again, and the control by the control unit or the output control unit may be re-executed according to the determination result of the determination unit. . By providing the determination means in this way, the fuel vapor adsorbed on the canister can be reliably purged. Further, when the fuel vapor is purged by driving the purge pump, it is possible to shorten the drive time of the purge pump, and to suppress power consumption.

Further, in the invention according to any one of claims 1 to 6 , as in the invention according to claim 7 , when the internal combustion engine is stopped and the travel motor serving as the travel source is driven, You may make it further provide the starting means which starts an internal combustion engine, when the density | concentration more than predetermined value is detected by the density | concentration detection means which detects the density | concentration of the hydrocarbon in a canister. As a result, when the amount of fuel vapor in the canister increases during traveling with the traveling motor and purge is required, the internal combustion engine can be started and purged, without opening the fuel vapor to the atmosphere, It becomes possible to purge appropriately.

As described above, according to the present invention, the fuel consumable amount of the internal combustion engine is detected, and when the detected fuel consumable amount is equal to or greater than a predetermined value, the fuel vapor is purged from the canister to the intake passage. A motor for controlling the pump so that the fuel vapor is purged by the negative intake air pressure of the internal combustion engine when the consumable amount of fuel is less than a predetermined value and the concentration of hydrocarbons in the canister is not less than a predetermined value; By controlling the output ratio of the internal combustion engine, the fuel vapor adsorbed on the canister can be efficiently purged, the fuel injected into the internal combustion engine can be reduced, and the fuel consumption can be improved. There is an effect.

  Hereinafter, an example of an embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a diagram showing a schematic configuration of each part of an evaporative fuel processing apparatus according to an embodiment of the present invention.

  In the evaporative fuel processing apparatus 10 according to the embodiment of the present invention, the evaporative fuel in the fuel tank 12 is adsorbed by the canister 14 and then purged to the intake passage 18 of the internal combustion engine (engine) 16.

  An oil supply hose 20 and a ventilation hose 22 are connected to the fuel tank 12, and fuel is supplied from the fuel hose 20 to the fuel tank 12, and air in the fuel tank 12 escapes from the ventilation hose 22 to the oil supply port during fueling.

  In the fuel tank 12, a remaining amount detection unit 26 that detects the remaining amount of fuel by a floater 24 floating on the fuel, and a fuel pump 28 that sends the fuel to the engine 16 are provided.

  A fuel tube 30 is connected to the fuel pump 28, and the fuel stored in the fuel tank 12 is sent to the engine 16. The fuel delivered by the fuel pump 28 is atomized and injected into the combustion chamber of the engine 16 from the injector 32 that injects the fuel.

  A breather pipe 34 connected to the canister 14 that adsorbs evaporated fuel is connected to the upper portion of the fuel tank 12.

  At the connection portion between the breather pipe 34 and the fuel tank 12, a vent valve 36, a COV (Cut Off Valve) 38 and a ROV (Roll Over Valve) 40 each comprising a floater valve are provided. The vent valve 36 opens when the internal pressure of the fuel tank 12 becomes higher than that of the breather pipe 34, and allows air including fuel vapor in the fuel tank 12 to flow to the canister 14 via the breather pipe 34.

  Further, the ROV 40 is closed when the liquid level rises during refueling, and the connection between the vent valve 36 and the fuel tank 12 is cut off. Further, the ROV 40 has a function of closing a connection portion between the vent valve 36 and the fuel tank 12 when the vehicle falls or the like and preventing a large amount of fuel from leaking to the outside through the breather pipe 34. The COV 38 is arranged in parallel with the ROV 40, and shuts off the communication between the vent valve 36 and the fuel tank 12 when the liquid level further rises above the ROV 40. When the liquid level rises during refueling, the COV 38 is opened even after the ROV 40 is closed and the fuel tank 12 and the vent valve 36 are communicated. However, when the liquid level reaches the COV 38 position due to the liquid level fluctuation caused by the vehicle turning. When the vehicle falls, the valve is closed and has a function of preventing the fuel from entering the breather pipe 34 through the vent valve 36.

  In addition to the breather pipe 34 described above, the canister 14 is connected to an atmospheric pipe 42 communicating with the atmosphere and a purge pipe 44 for purging fuel vapor adsorbed on the canister 14, and a concentration sensor 46 is connected to the atmosphere. It is provided at the connection portion of the pipe 42. The concentration detection sensor 46 detects the concentration of HC (hydrocarbon) in order to detect the amount of fuel vapor adsorbed on the canister 14.

  The atmosphere pipe 42 is provided with a CCV (Canister Clousure Valve) 48 and an air filter 50, and the atmosphere is taken into the canister 14 by opening and closing the CCV 48.

  The purge pipe 44 is provided with a purge pump 52 for forcibly purging the fuel vapor adsorbed on the canister 14 into the intake passage 18 of the engine 16, and a purge control valve is provided between the purge pipe 44 and the intake passage 18. 54 is provided.

  Next, the configuration of the control system of the evaporated fuel processing apparatus according to the embodiment of the present invention will be described. FIG. 2 is a block diagram showing the configuration of the control system of the evaporated fuel processing apparatus according to the embodiment of the present invention.

  Processing of fuel vapor adhering to the engine 16 and the canister 14 is controlled by an ECU (Electronic Control Unit) 60.

  The ECU 60 includes a microcomputer in which a CPU 60A, a RAM 60B, a ROM 60C, and an input / output interface (I / O) 60D are connected to a buzz 60E.

  An injector 32, an ignition device 62, a throttle position sensor 64, a water temperature sensor 66, an intake air temperature sensor 68, an O2 sensor 70, an exhaust gas temperature sensor 72, an intake air amount sensor 74, and the like are connected to the I / O 60D.

  The ROM 60C stores a fuel injection map in which the fuel injection amount of the injector 32 is determined in advance for each engine speed, an ignition map in which the ignition timing is determined, and the CPU 60A includes a throttle position sensor 64, a water temperature sensor 66, The engine is controlled by controlling the fuel injected from the injector 32 and the ignition timing by the ignition device 62 based on the detection results of various sensors such as the intake air temperature sensor 68, the O2 sensor 70, the exhaust gas temperature sensor 72, and the intake air amount sensor 74. 16 operations are controlled.

  Further, the ROM 60C stores a correction value, a correction map, and the like of the fuel injection map when purging the fuel vapor of the canister 14, and the CPU 60A uses the correction value, the correction map, etc. to store the fuel from the injector 32. By correcting the injection amount, the air fuel consumption of the engine 16 when the fuel vapor of the canister 14 is purged into the intake passage 18 is maintained at an appropriate air fuel consumption such as the theoretical air fuel consumption.

  Further, in the present embodiment, a hybrid motor 76 is provided as a travel source other than the engine 16, and the ECU 60 controls the engine 16 and the hybrid motor 76 in accordance with the travel state and the like.

  The ECU 60 is connected to a concentration sensor 46, a purge pump 52, a CCV 48, a purge control valve 54, and a battery load detection circuit 78. The ECU 60 controls the purge pump, CCV 48, purge control valve 54 and the like based on the detection result of the concentration sensor 46. Based on the battery load detected by the battery load detection circuit 78, the operation of the purge pump is controlled. The battery load detection circuit 78 detects the battery load by detecting, for example, the difference between the charge amount and the battery consumption amount.

  Here, the purge control of the canister 14 performed by the ECU 60 of the evaporated fuel processing apparatus 10 according to the embodiment of the present invention configured as described above will be described in detail. FIG. 3 is a flowchart showing an example of the flow of the fuel purge process performed by the ECU 60 of the evaporated fuel processing apparatus 10 according to the embodiment of the present invention.

  In step 100, the ECU 60 determines whether or not the engine is on. If the determination is negative, the process proceeds to step 102, and if the determination is affirmative, the process proceeds to step 108.

  In step 102, the hybrid motor 76 is turned on by the ECU 60, and the routine proceeds to step 104. That is, traveling by the hybrid motor 76 is performed.

  In step 104, the ECU 60 determines whether or not the HC concentration is equal to or higher than a predetermined value from the detection result of the concentration sensor 46. If the determination is affirmative, the process proceeds to step 106, and if negative, the fuel purge is performed. The process is returned and other processes and the fuel purge process are executed from step 100.

  In step 106, the engine 16 is turned on and the routine proceeds to step 108. That is, when the HC concentration of the canister 14 increases during traveling by the hybrid motor 76, the engine 16 is turned on and purged.

  On the other hand, in step 108, it is determined by the ECU 60 whether the fuel consumable amount is equal to or greater than a predetermined value. The determination is made, for example, by determining whether or not the throttle opening detected by the throttle position sensor 64 is greater than or equal to a predetermined value, or determining whether or not the rotational speed of the engine 16 is greater than or equal to a predetermined value from the ignition timing of the ignition device 62. Or by determining whether or not the negative pressure in the intake passage 18 is equal to or less than a predetermined value. If the determination is affirmative, the process proceeds to step 110; Migrate to

  In step 110, the ECU 60 determines from the detection result of the concentration sensor 46 whether or not the HC concentration is equal to or higher than a predetermined value. If the determination is affirmative, the process proceeds to step 111. If the determination is negative, fuel purge processing is performed. The other processes and the fuel purge process are executed from step 100.

  In step 111, the CCV 48 and the purge control valve 54 are opened by the ECU 60, and the process proceeds to step 112.

  In step 112, the ECU 60 determines whether or not the battery load detected by the battery load detection circuit 78 is equal to or greater than a predetermined value. If the determination is affirmative, the process proceeds to step 114. If the determination is negative, step 118 is performed. Migrate to

  In step 114, the purge pump is turned on by the ECU 60, and the process proceeds to step 120. That is, when the CCV 48 and the purge control valve 54 are opened and the purge pump 52 is driven, the fuel vapor adsorbed on the canister 14 is forcibly purged. At this time, since the hybrid motor output may be increased in step 118, when the hybrid motor output is increased, the output increase is canceled and the purge pump 52 is driven.

  On the other hand, in step 116, the ECU 60 determines whether or not the HC concentration is equal to or higher than a predetermined value from the detection result of the concentration sensor 46. If the determination is affirmative, the process proceeds to step 117. Migrate to

  In step 117, the CCV 48 and the purge control valve 54 are opened by the ECU 60, and the process proceeds to step 118.

  In step 118, the output of the hybrid motor 76 is increased by an instruction from the ECU 60, and the process proceeds to step 120. That is, by increasing the output of the hybrid motor 76, the power performance required by the driver can be obtained even if the output of the engine 16 is small, and the opening of the throttle 19 is reduced to reduce the negative pressure in the intake passage 18. Therefore, the engine negative pressure in the intake passage 18 is increased by controlling the ratio of the output of the hybrid motor 76 and the output of the engine 16. Therefore, since the CCV 48 and the purge control valve 54 are opened, the fuel vapor adsorbed on the canister 14 is purged by the engine negative pressure. At this time, since the purge pump 52 may be turned on in step 114, when the purge pump 52 is turned on, the purge pump 52 is turned off and the output of the hybrid motor 76 is increased.

  In step 120, it is determined by the ECU 60 whether or not the HC concentration is less than a predetermined value from the detection result of the concentration sensor 46. If the determination is negative, the process proceeds to step 108 described above. Control goes to step 122.

  In step 122, the ECU 60 determines whether purge control is being performed. In this determination, it is determined whether the CCV 48 and the purge control valve 54 are opened and purge control is being performed. If the determination is affirmative, the routine proceeds to step 124; The purge process is returned, and other processes and the fuel purge process are executed from step 100.

  In step 124, the purge control being executed is reset by the ECU 60, that is, after the purge pump or hybrid motor output up control or the like is reset by the ECU 60, the fuel purge process is returned to perform other processes or the fuel purge process. Are executed from step 100.

  As described above, in the present embodiment, when the fuel consumable amount is equal to or greater than the predetermined value, the opening degree of the throttle 19 becomes large and the negative pressure in the intake passage 18 decreases. In this case, the purge pump 52 is turned on and the fuel vapor of the canister 14 is forcibly purged. As a result, when the negative pressure in the intake passage 18 is low and cannot be purged by the negative pressure of the engine 16, the purge can be performed by the purge pump 52. When the fuel consumption amount is large, that is, when the engine 16 needs fuel, the fuel vapor is purged into the intake passage 18 so that the fuel vapor in the canister 14 can be efficiently purged, and the engine 16 Since it is not necessary to purge in the case of idling that does not require an output or in a low load state, the engine 16 can be turned off or the output can be reduced, and fuel consumption can be improved.

  Further, when the purge amount of the fuel vapor adsorbed on the canister 14 is detected by the concentration sensor 46 instead of always turning on the purge pump 52, the purge of the fuel vapor is required, and the amount of fuel that can be consumed is large. Furthermore, since the purge pump 52 is driven and forced purge is performed, the power consumption of the purge pump 52 can be suppressed, and the fuel vapor is purged when there is a large amount of fuel that can be consumed, so the fuel injected from the injector 32 is reduced. Thus, fuel efficiency can be improved and purge efficiency can be improved.

  Further, since the HC concentration of the canister 14 is detected by the concentration sensor 46 before and after purging, when the purge pump 52 is driven, the operation time can be shortened while ensuring the purge amount.

  Further, since the battery load is detected and the purge pump 52 is turned on / off, the purge pump 52 can be driven so that the battery power does not become insufficient.

  Further, if the purge is necessary when the amount of fuel that can be consumed is small, or if the purge pump 52 cannot be driven due to a large battery load, the output of the hybrid motor 76 can be increased so that the output of the engine 16 is small. The power performance required by the driver can be obtained, and the opening of the throttle 19 can be reduced to increase the negative pressure in the intake passage 18. Therefore, the fuel vapor in the canister 14 is purged with the negative intake pressure in the engine 16. can do.

  Further, while the engine 16 is stopped and the hybrid motor 76 is traveling, the HC concentration in the canister 14 is detected by the concentration sensor 46 and the engine is turned on / off, so that the fuel in the canister 14 is traveling while the hybrid motor 76 is traveling. When the amount of vapor becomes large and purge is required, the engine 16 can be started and purged, and the fuel vapor can be appropriately purged without opening it to the atmosphere.

  In addition, since the HC concentration in the canister 14 is detected before and after purging to determine whether or not purging is necessary again, the purge control is performed, so that the fuel vapor in the canister 14 can be reliably purged and the purge pump 52 is driven. When purging the fuel vapor, the purge pump drive time can be shortened and power consumption can be suppressed.

  Furthermore, since the purge by the negative pressure of the engine 16 and the forced purge by the purge pump 52 are switched according to the situation, the fuel vapor of the canister 14 can be purged by an appropriate purge method, and the necessary purge amount can be reduced. It can be ensured and the amount of HC emissions can be reduced.

  In the above-described embodiment, the purge pump is driven when the fuel consumable amount is not less than the predetermined value, the HC concentration is not less than the predetermined value, and the battery load is not more than the predetermined value. 112 may be omitted and the purge pump 52 may be driven when the fuel consumable amount is equal to or greater than a predetermined value, or the step 112 may be omitted and the fuel consumable amount is equal to or greater than the predetermined value and the HC concentration is a predetermined value. In the above case, the purge pump 52 may be driven.

  Further, in the above embodiment, when the fuel consumable amount is less than the predetermined value and the HC concentration is the predetermined value or more, the output of the hybrid motor 76 is increased and the fuel vapor of the canister 14 is increased by the pressure of the intake passage 18. However, the present invention is not limited to this, and when the fuel consumption amount is less than a predetermined value and the HC concentration is equal to or higher than the predetermined value, the purge pump 52 is driven according to the battery load to drive the fuel of the canister 14. The vapor may be forcibly purged, or the transmission may be further controlled to increase the output of the engine 16 and change the gear ratio in response to the increase in engine output, and then to the purge pump 52 in accordance with the battery load. And the fuel vapor of the canister 14 may be forcibly purged.

It is a figure which shows schematic structure of each part of the evaporative fuel processing apparatus concerning embodiment of this invention. It is a block diagram which shows the structure of the control system of the evaporative fuel processing apparatus concerning embodiment of this invention. It is a flowchart which shows an example of the flow of the fuel purge process performed by ECU of the evaporative fuel processing apparatus concerning embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Evaporative fuel processing apparatus 12 Fuel tank 14 Canister 16 Engine 18 Intake passage 46 Concentration sensor 52 Purge pump 60 ECU
62 Ignition System 64 Throttle Position Sensor 76 Hybrid Motor 78 Battery Load Detection Circuit

Claims (7)

Detecting means for detecting the fuel consumption possible amount required by the internal combustion engine;
A purge pump for purging the fuel vapor to the intake passage of the internal combustion engine from a canister that adsorbs fuel vapor generated in the fuel tank;
Control means for controlling the purge pump so as to purge the fuel vapor from the canister to the intake passage when the consumable amount of fuel detected by the detection means is a predetermined value or more;
The intake air of the internal combustion engine when the fuel consumable amount detected by the detection means is less than a predetermined value and the concentration detected by the concentration detection means for detecting the concentration of hydrocarbons in the canister is greater than or equal to a predetermined value. An output control means for controlling the output ratio of the running motor and the internal combustion engine as a running source so as to purge the fuel vapor into the intake passage of the internal combustion engine by negative pressure;
An evaporative fuel processing apparatus.   The control means is configured when the fuel consumption possible amount detected by the detection means is not less than a predetermined value and the concentration detected by the concentration detection means for detecting the hydrocarbon concentration in the canister is not less than a predetermined value. The evaporated fuel processing apparatus according to claim 1, wherein the purge pump is controlled.   When the control unit is controlled to drive the purge pump, the control unit controls to stop driving the purge pump when the concentration detected by the concentration detection unit becomes less than a predetermined value. The evaporative fuel processing apparatus according to claim 2, wherein   The control means is detected by a load detection means for detecting the battery load when the consumable amount of fuel detected by the detection means is not less than a predetermined value, the concentration detected by the concentration detection means is not less than a predetermined value. The evaporated fuel processing apparatus according to claim 2 or 3, wherein the purge pump is controlled when a battery load is equal to or less than a predetermined value. The output control means serves as a travel source so as to purge the fuel vapor into the intake passage of the internal combustion engine by the intake negative pressure of the internal combustion engine when the battery load detected by the battery load detection means exceeds a predetermined value. evaporative fuel processing apparatus according to claim 4, and Turkey to control the output ratio of the traction motor and an internal combustion engine characterized. After the control by the control means or the output control means is executed, is the control by the control means or the output control means necessary again based on the detection result of the concentration detection means for detecting the hydrocarbon concentration in the canister? 6. The apparatus according to claim 1, further comprising a determination unit that determines whether or not, and re-execution of control by the control unit or the output control unit in accordance with a determination result of the determination unit. The evaporative fuel processing apparatus of description. When the internal combustion engine is stopped and the travel motor serving as a travel source is being driven, the internal combustion engine is detected when the concentration detection means for detecting the concentration of hydrocarbons in the canister detects a concentration greater than a predetermined value. The evaporative fuel processing apparatus according to claim 1, further comprising start means for starting the engine .

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