JP2016222144A - Hybrid automobile - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize better fuel economy for a vehicle.SOLUTION: Control includes: setting lower limit torque Temin and upper limit torque Temax of an engine in accordance with a revolution speed Ne of the engine (S130) in a case where a power storage ratio SOC of a battery is within a range of thresholds Smin-Smax (S120); setting basic torque Tetmp to target torque Te* of the engine (S190) in a case where basic torque Tetmp of the engine in accordance with an accelerator opening degree falls within a range of the lower limit torque Temin and upper limit torque Temax (S140); and disengaging a clutch without driving a motor (i.e., not charging the battery) (S200) and controlling the engine so that the engine is operated at a basis operation point that consists of a revolution speed Ne and basic torque Tetmp (S210).SELECTED DRAWING: Figure 2

Description

  The present invention relates to a hybrid vehicle, and more particularly, to a hybrid vehicle including an engine, a motor, a transmission, a clutch, and a battery.

  Conventionally, this type of hybrid vehicle includes an internal combustion engine, a transmission connected to the crankshaft and drive wheels of the internal combustion engine, a generator motor, and an output shaft of the generator motor between the internal combustion engine and the transmission. In a configuration including an intermittent power interrupting mechanism and a battery that exchanges electric power with a generator motor, a mechanism that intermittently controls the power interrupting mechanism in order to improve the fuel efficiency of the vehicle has been proposed (see, for example, Patent Document 1). ). In this hybrid vehicle, road information (whether the road is an expressway, a motorway or a general road, etc.), traffic information (traffic jam, traffic accident, road construction, weather, etc.), vehicle information (charge voltage from the battery, etc.) The power intermittent mechanism is intermittently controlled based on at least one.

JP 2011-105158 A

  In such a hybrid vehicle, the operating efficiency of the internal combustion engine can be improved by bringing the operating point of the internal combustion engine closer to the fuel efficiency operation line for operating the internal combustion engine more efficiently than the basic operating point according to the accelerator operation amount. it can. At this time, the battery is charged / discharged by driving the generator motor according to the power corresponding to the amount of the operating point of the internal combustion engine closer to the fuel consumption operating line than the basic operating point. By the way, when the basic operating point is within the predetermined operating range including the fuel efficiency operating line, if the operating point is closer to the fuel efficiency operating line than the basic operating point, the fuel efficiency improvement cost of the vehicle due to the improvement of the driving efficiency of the internal combustion engine, Deterioration of the fuel consumption of the vehicle due to charge / discharge loss when the generator motor is driven to charge / discharge the battery tends to increase. Therefore, at this time, it is preferable to set the operating point as a basic operating point and not drive the generator motor, that is, not charge / discharge the battery. However, in this case, drag loss occurs in the generator motor due to the rotation of the generator motor. Therefore, it is required to suppress the occurrence of drag loss in the generator motor and further improve the fuel consumption of the vehicle.

  The main purpose of the hybrid vehicle of the present invention is to further improve the fuel consumption of the vehicle.

  The hybrid vehicle of the present invention employs the following means in order to achieve the main object described above.

The hybrid vehicle of the present invention
An engine capable of outputting power,
A transmission connected to the output shaft of the engine and a drive shaft coupled to the axle;
A motor capable of inputting and outputting power;
A clutch for connecting and releasing the connection between the motor and the output shaft or the drive shaft;
A battery capable of exchanging power with the motor;
A hybrid vehicle comprising:
Control means for controlling the clutch so as to release the clutch when the storage ratio of the battery is within a predetermined range and the operating point of the engine according to the accelerator operation amount is within a predetermined operating range including a fuel efficiency operation line;
It is a summary to provide.

  In the hybrid vehicle according to the present invention, when the storage ratio of the battery is within a predetermined range and the engine operating point corresponding to the accelerator operation amount (hereinafter referred to as “basic operating point”) is within a predetermined operating range including the fuel efficiency operating line. Control the clutch to release the clutch. Here, the fuel consumption operation line is set in advance as an operation line for efficiently operating the engine. The predetermined range is determined in advance as a range of the power storage ratio that does not require the battery to be forcibly charged or discharged (the battery need not be charged / discharged). In addition, when the operating point of the engine is closer to the fuel efficiency operation line than the basic operating point, the predetermined operating range drives the motor to charge / discharge the battery rather than the cost of improving the fuel efficiency of the vehicle by improving the engine operating efficiency. The range of deterioration of the fuel consumption of the vehicle due to the charging / discharging loss at the time is likely to increase (totally, the fuel consumption of the vehicle tends to deteriorate). When the storage ratio of the battery is within the predetermined range and the basic operating point is within the predetermined operating range, there is no need to forcibly charge and discharge the battery, and the operating point is brought closer to the fuel consumption operating line than the basic operating point (battery Charging / discharging) tends to deteriorate the fuel consumption of the vehicle. Therefore, at this time, it is preferable to set the operating point as a basic operating point and not drive the motor, that is, not charge / discharge the battery. However, if the motor is connected to the output shaft or the drive shaft when the motor is not driven, drag loss occurs in the motor due to the rotation of the motor. In the hybrid vehicle of the present invention, when the motor is not driven (when the battery is not charged / discharged), the clutch can be released to prevent drag loss in the motor. As a result, the fuel consumption of the vehicle can be further improved.

  In such a hybrid vehicle according to the present invention, the control means disengages the clutch so as to release the clutch when the power storage ratio is within the predetermined range and the operating point (basic operating point) is within the predetermined operating range. In addition to controlling, the engine may be controlled such that the engine is operated at the operating point and the motor is not driven. The control means controls the clutch so as to engage the clutch when the power storage ratio is within the predetermined range and the operating point (basic operating point) is outside the predetermined operating range, and The engine is controlled so that the engine is operated at a changed operating point closer to the fuel efficiency operating line than the operating point within the range up to the predetermined operating range, and the deviation between the operating point and the changed operating point is controlled. It is good also as a means which controls the said motor so that the said motor may be driven according to.

1 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 20 as an embodiment of the present invention. It is a flowchart which shows an example of the control routine performed by ECU70 of an Example. It is explanatory drawing which shows an example of the fuel consumption operation line which drives the engine 22 efficiently, and the predetermined operation range containing the fuel consumption operation line.

  Next, the form for implementing this invention is demonstrated using an Example.

  FIG. 1 is a configuration diagram showing an outline of the configuration of a hybrid vehicle 20 as an embodiment of the present invention. The hybrid vehicle 20 of the embodiment includes an engine 22, a transmission 30, a motor MG, an inverter 42, a battery 50, a clutch 60, and an electronic control unit (hereinafter referred to as “ECU”) 70, as illustrated. And comprising.

  The engine 22 is configured as an internal combustion engine that outputs power using gasoline or light oil as a fuel.

  The transmission 30 is configured, for example, as an eight-speed automatic transmission that is hydraulically driven. The input shaft 32 is connected to the crankshaft 26 of the engine 22 and the output shaft 34 is differentially connected to the drive wheels 38a and 38b. It is connected to a drive shaft 36 connected through a gear 37. The transmission 30 changes the power of the crankshaft 26 of the engine 22 in eight stages and outputs it to the drive shaft 36.

  The motor MG is configured as a synchronous generator motor, for example. The motor MG has a rotating shaft 46 connected to the crankshaft 26 of the engine 22 via a clutch 60. The inverter 42 is connected to the battery 50 via the power line 54. Motor MG is rotationally driven by ECU 70 by switching control of a plurality of switching elements (not shown) of inverter 42.

  The battery 50 is configured as, for example, a lithium ion secondary battery or a nickel hydride secondary battery. As described above, the battery 50 is connected to the inverter 42 via the power line 54.

  The clutch 60 is configured as, for example, a hydraulically driven friction clutch, and is provided between the rotating shaft 46 of the motor MG and the crankshaft 26 of the engine 22 as described above. The clutch 60 connects the rotation shaft 46 of the motor MG and the crankshaft 26 of the engine 22 when engaged, and releases the connection between the rotation shaft 46 of the motor MG and the crankshaft 26 of the engine 22 when released.

Although not shown, the ECU 70 is configured as a microprocessor centered on a CPU, and includes a ROM for storing a processing program, a RAM for temporarily storing data, and an input / output port in addition to the CPU. Signals from various sensors are input to the ECU 70 via input ports. Examples of signals from various sensors include the following.
A crank angle θcr from a crank position sensor 23 that detects the rotational position of the crankshaft 26 of the engine 22
・ Throttle opening TH from the throttle valve position sensor that detects the throttle valve position of the engine 22
The rotational speed Nin of the input shaft 32 from the rotational speed sensor attached to the input shaft 32 of the transmission 30
The rotational speed Nout of the output shaft 34 from the rotational speed sensor attached to the output shaft 34 of the transmission 30
A rotational position θm from a rotational position detection sensor 44 that detects the rotational position of the rotor of the motor MG.
A phase current from a current sensor that detects a current flowing in each phase of the motor MG A battery voltage Vb from a voltage sensor 51a installed between terminals of the battery 50
Battery current Ib from current sensor 51b attached to the output terminal of battery 50
The battery temperature Tb from the temperature sensor 51c attached to the battery 50
-Ignition signal from the ignition switch 80-Shift position SP from the shift position sensor 82 that detects the operation position of the shift lever 81
Accelerator opening degree Acc from the accelerator pedal position sensor 84 that detects the depression amount of the accelerator pedal 83
-Brake pedal position BP from the brake pedal position sensor 86 that detects the amount of depression of the brake pedal 85
・ Vehicle speed V from vehicle speed sensor 88

Various control signals are output from the ECU 70 via an output port. Examples of various control signals include the following.
-Control signal to the fuel injection valve-Control signal to the throttle motor that adjusts the position of the throttle valve-Control signal to the ignition coil integrated with the igniter-Switching control signal to the switching element (not shown) of the inverter 42-Clutch Control signal for controlling ON / OFF of 60

  The ECU 70 calculates the rotation speed of the crankshaft 26, that is, the rotation speed Ne of the engine 22 based on the crank angle θcr from the crank position sensor 23. Further, the ECU 70 calculates the rotational speed Nm of the motor MG based on the rotational position θm of the rotor of the motor MG from the rotational position detection sensor 44. Furthermore, the ECU 70 calculates the storage ratio SOC based on the integrated value of the battery current Ib from the current sensor 51b. The storage ratio SOC is a ratio of the capacity of power that can be discharged from the battery 50 to the total capacity of the battery 50.

  In the hybrid vehicle 20 of the embodiment thus configured, the ECU 70 sets the target gear stage S * of the transmission 30 based on the accelerator opening Acc from the accelerator pedal position sensor 84 and the vehicle speed V from the vehicle speed sensor 88. The transmission 30 is controlled so that the speed S of the transmission 30 becomes the target speed S *. Further, the ECU 70 sets a required torque Tout * required for the drive shaft 36 based on the accelerator opening Acc and the vehicle speed V, and the set required torque Tout * is a gear ratio corresponding to the gear stage S of the transmission 30. A required torque Tin * required for the input shaft 32 of the transmission 30 is set by dividing by Gr. The engine 22, the motor MG, and the clutch 30 are controlled so that the required torque Tin * is output to the input shaft 32 of the transmission 30.

  Next, the operation of the hybrid vehicle 20 of the embodiment thus configured, particularly the control of the engine 22, the motor MG, and the clutch 60 will be described. FIG. 2 is a flowchart illustrating an example of a control routine executed by the ECU 70 of the embodiment. This routine is repeatedly executed every predetermined time (for example, every several msec).

  When the control routine is executed, the ECU 70 first inputs data such as the storage ratio SOC of the battery 50, the rotational speed Ne of the engine 22, and the required torque Tin * of the input shaft 32 of the transmission 30 (step S100). Here, as the storage ratio SOC, a value calculated based on the battery current Ib input from the current sensor 51a is input. As the rotational speed Ne of the engine 22, a value calculated based on a signal from the crank position sensor 23 is input. As described above, the required torque Tin * is a value set based on the accelerator opening Acc and the vehicle speed V.

  When the data is input in this way, the required torque Tin of the input shaft 32 of the transmission 30 is taken into consideration that the rotational speed Ne of the crankshaft 26 of the engine 22 and the rotational speed Nin of the input shaft 32 of the transmission 30 become the same. * Is set to the basic torque Ttmp of the engine 22 (step S110). Subsequently, the storage ratio SOC of the battery 50 is compared with threshold values Smin and Smax (step S120). Here, the threshold values Smin and Smax are determined in advance as the lower and upper limits of the range of the storage ratio SOC that does not require the battery 50 to be forcibly charged and discharged (the battery need not be charged and discharged). Values such as% and 45% can be used, and values such as 75% and 80% can be used as the threshold value Smax.

  When the storage ratio SOC of the battery 50 is smaller than the threshold value Smin or larger than the threshold value Smax in step S120, the target torque Te * of the engine 22 is set based on the basic torque Tempmp of the engine 22 (step S150). A torque command Tm * for the motor MG is set based on the target torque Te * (step S160). Then, the clutch 60 is controlled so that the clutch 60 is engaged from the disengagement or the engagement is maintained (step S170), and the engine 22 is operated at a target operating point consisting of the rotational speed Ne and the target torque Te *. Thus, the engine 22 is controlled and the switching element of the inverter 42 is controlled to be driven so that the motor MG is driven by the torque command Tm * (step S180), and this routine is finished.

  Here, the processing of steps S150 and S160 when the storage ratio SOC of the battery 50 is smaller than the threshold value Smin or larger than the threshold value Smax will be described. When the storage ratio SOC of the battery 50 is smaller than the threshold value Smin, a torque (Ttmp + ΔTe) obtained by adding a positive predetermined torque ΔTe to the basic torque Tempmp is set as the target torque Te * and the predetermined torque ΔTe is multiplied by a value (−1). Torque (−ΔTe) is set to the torque command Tm * of the motor MG. Thereby, the battery 50 is charged with power according to the torque (−ΔTe) and the rotation speed Nm of the motor MG. As a result, the storage ratio SOC of the battery 50 can be brought close to the threshold value Smin. When the storage ratio SOC of the battery 50 is smaller than the threshold value Smax, a torque (Temp−ΔTe) obtained by subtracting the predetermined torque ΔTe from the basic torque Tempmp is set as the target torque Te *, and the predetermined torque ΔTe is set to the torque command Tm * of the motor MG. Set to. Thereby, the battery 50 is discharged with power according to the predetermined torque ΔTe and the rotation speed Nm of the motor MG. As a result, the storage ratio SOC of the battery 50 can be brought close to the threshold value Smax. The predetermined torque ΔTe may be a torque obtained by dividing the charge / discharge power Pb * of the battery 50 by the rotational speed Ne of the engine 22, or may be a uniform value.

  When the storage ratio SOC of the battery 50 is not less than the threshold value Smin and not more than the threshold value Smax in step S120, the lower limit torque Temin and the upper limit torque Temax of the engine 22 are set based on the rotational speed Ne of the engine 22 (step S130). FIG. 3 is an explanatory diagram showing an example of a fuel efficiency operation line and a predetermined operation range including the fuel efficiency operation line. Here, the fuel efficiency operation line is determined in advance as an operation line for efficiently operating the engine 22. Further, the predetermined operating range brings the target operating point consisting of the rotational speed Ne and the target torque Te * of the engine 22 closer to the fuel consumption operating line than the basic operating point consisting of the rotational speed Ne and the basic torque Tempmp (moves from the basic operating point). When the motor MG is driven to charge / discharge the battery 50, the cost of deterioration of the vehicle's fuel consumption tends to be larger than the cost of improving the fuel efficiency of the vehicle due to the improvement of the driving efficiency of the engine 22 ( It is determined in advance as a range in which the vehicle fuel consumption tends to deteriorate as a whole. Therefore, when the basic operating point is within the predetermined operating range, if the target operating point is brought closer to the fuel consumption operation line than the basic operating point (moved from the basic operating point), the fuel consumption of the vehicle is likely to deteriorate, and the basic operating point becomes the predetermined operation. When out of the range, it can be said that the fuel efficiency of the vehicle is likely to be improved by bringing the target operating point closer to the fuel efficiency operating line than the basic operating point within the range up to the boundary of the predetermined operating range. As shown in FIG. 3, the lower limit torque Temin and the upper limit torque Temax can be obtained as intersections between the rotational speed Ne of the engine 22 and a line indicating the lower limit and the upper limit of the predetermined operating range.

  When the lower limit torque Temin and the upper limit torque Temax of the engine 22 are thus set, the basic torque Tetmp of the engine 22 is compared with the lower limit torque Temin and the upper limit torque Temax (step S140). When the basic torque Tetmp of the engine 22 is smaller than the lower limit torque Temin or larger than the upper limit torque Temax (when the basic operating point of the engine 22 is outside the predetermined operating range), the basic torque Tetmp of the engine 22 is used. Then, the target torque Te * of the engine 22 is set (step S150), and the torque command Tm * of the motor MG is set based on the set target torque Te * (step S160). Then, the clutch 60 is controlled so that the clutch 60 is engaged from the disengagement or the engagement is maintained (step S170), and the engine 22 is operated at a target operating point consisting of the rotational speed Ne and the target torque Te *. Thus, the engine 22 is controlled and the switching element of the inverter 42 is controlled to be driven so that the motor MG is driven by the torque command Tm * (step S180), and this routine is finished.

  Here, the processing of steps S150 and S160 when the basic torque Temptmp of the engine 22 is smaller than the lower limit torque Temin or larger than the upper limit torque Temax (when the basic operating point of the engine 22 is outside the predetermined operating range) will be described. . When the basic torque Tempmp of the engine 22 is smaller than the lower limit torque Temin, the lower limit torque Temin is set to the target torque Te * of the engine 22, and the torque obtained by subtracting the lower limit torque Temin from the basic torque Tempmp (Tempm−Temin) is set to the motor MG. Set to torque command Tm *. As a result, the engine 22 outputs the lower limit torque Temin (torque at the lower limit of the predetermined operation range) closer to the fuel efficiency operation line than the basic torque Tetmp, so that the fuel efficiency of the vehicle can be improved. At this time, since the motor MG1 is driven (regeneratively driven) with torque (Tempp-Temin), the battery 50 has power according to the torque (Tempp-Temin) and the rotational speed Nm of the motor MG. Charged. When the basic torque Tempmp of the engine 22 is larger than the upper limit torque Temax, the upper limit torque Temax is set to the target torque Te * of the engine 22, and the torque (Ttmp-Temax) obtained by subtracting the upper limit torque Temin from the basic torque Tempmp is set to the motor MG. Set to torque command Tm *. As a result, the engine 22 outputs the upper limit torque Temax closer to the fuel consumption operation line than the basic torque Tetmp (the upper limit torque of the predetermined operation range), so that the fuel consumption of the vehicle can be improved. At this time, since the motor MG1 is driven (powered) by the torque (Tempp-Temax), the battery 50 has a power corresponding to the torque (Tempp-Temax) and the rotational speed Nm of the motor MG. Discharged.

  When the basic torque Tetmp of the engine 22 is not less than the lower limit torque Temin and not more than the upper limit torque Temax in step S140 (when the basic operating point of the engine 22 is within a predetermined operating range), the basic torque Tetmp of the engine 22 is The target torque Te * is set (step S190). Then, the clutch 60 is controlled so that the clutch 60 is disengaged or kept released (step S200), and the engine 22 is operated at a target operating point consisting of the rotational speed Ne and the target torque Te *. Then, the engine 22 is controlled (step S210), and this routine is finished. As described above, when the basic operating point of the engine 22 is within the predetermined operating range, the fuel efficiency of the vehicle is likely to deteriorate if the target operating point is moved closer to the fuel efficiency operating line than the basic operating point (moved from the basic operating point). For this reason, it is preferable to set the basic operating point as the target operating point. When the basic operating point is set as the target operating point, it is not necessary to charge / discharge the battery 50. Therefore, in the embodiment, the motor MG is not driven. However, when the motor MG is not driven and the clutch 60 is engaged and the motor MG and the crankshaft 26 of the engine 22 are connected, the motor MG is rotated and dragging loss occurs in the motor MG. . Based on this, in the embodiment, the clutch 60 is released when the motor MG is not driven (when the battery 50 is not charged / discharged). Thereby, generation | occurrence | production of the drag loss in motor MG can be suppressed. As a result, the fuel consumption of the vehicle can be further improved.

  In the hybrid vehicle 20 of the embodiment described above, when the storage ratio SOC of the battery 50 is not less than the threshold value Smin and not more than the threshold value Smax, the lower limit torque Temin and the upper limit torque of the engine 22 according to the engine speed Ne. Set Temax. When the basic torque Tempmp of the engine 22 corresponding to the accelerator opening degree Acc is within the range of the lower limit torque Temin and the upper limit torque Temax, the engine 22 is operated at a basic operating point consisting of the rotational speed Ne and the basic torque Tempmp. The engine 22 is controlled so that the motor MG is not driven (the battery 50 is not charged / discharged), and the clutch 60 is released. Thereby, when the motor MG is not driven (when the battery 50 is not charged / discharged), the occurrence of drag loss in the motor MG can be suppressed. As a result, the fuel consumption of the vehicle can be further improved.

  In the hybrid vehicle 20 of the embodiment, the basic torque Tempmp of the engine 22 is compared with the lower limit torque Temin and the upper limit torque Temax when the storage ratio SOC of the battery 50 is in the range not less than the threshold value Smin and not more than the threshold value Smax (engine 22 It is determined whether the operating point is closer to the fuel consumption operating line than the basic operating point). However, instead of the basic torque Tetmp of the engine 22, the estimated torque Test of the engine 22 estimated based on the intake air amount of the engine 22 and the throttle opening TH of the throttle valve is compared with the lower limit torque Temin and the upper limit torque Temax. It may be a thing.

  In the hybrid vehicle 20 of the embodiment, the rotation shaft 46 of the motor MG is connected to the crankshaft 26 of the engine 22 via the clutch 60, that is, the rotation shaft 46 of the motor MG and the crankshaft 26 of the engine 22 are connected by the clutch 60. Connection and disconnection shall be performed. However, the rotation shaft 46 of the motor MG may be connected to the drive shaft 36 via the clutch 60, that is, the connection between the rotation shaft 46 of the motor MG and the drive shaft 36 and the connection release may be performed by the clutch 60.

  The hybrid vehicle 20 of the embodiment is provided with the eight-speed transmission 30, but is not limited to the eight-speed transmission, and is a four-speed, five-speed, six-speed, etc. Any number of stages of transmissions may be provided. Further, a continuously variable transmission may be provided instead of the stepped transmission.

  The correspondence between the main elements of the embodiment and the main elements of the invention described in the column of means for solving the problems will be described. In the embodiment, the engine 22 corresponds to “engine”, the transmission 30 corresponds to “transmission”, the motor MG corresponds to “motor”, the clutch 60 corresponds to “clutch”, and the battery 50 corresponds to “ The ECU 70 corresponds to “control means”.

  The correspondence between the main elements of the embodiment and the main elements of the invention described in the column of means for solving the problem is the same as that of the embodiment described in the column of means for solving the problem. Therefore, the elements of the invention described in the column of means for solving the problems are not limited. In other words, the interpretation of the invention described in the column of means for solving the problem should be made based on the description of the column, and the examples are those of the invention described in the column of means for solving the problem. It is only a specific example.

  As mentioned above, although the form for implementing this invention was demonstrated using the Example, this invention is not limited at all to such an Example, In the range which does not deviate from the summary of this invention, it is with various forms. Of course, it can be implemented.

  The present invention can be used in the automobile manufacturing industry.

  20 hybrid vehicle, 22 engine, 23 crank position sensor, 26 crankshaft, 30 transmission, 32 input shaft, 34 output shaft, 36 drive shaft, 37 differential gear, 38a, 38b drive wheel, 42 inverter, 44 rotational position detection sensor , 46 Rotating shaft, 50 Battery, 51a Voltage sensor, 51b Current sensor, 51c Temperature sensor, 54 Power line, 60 Clutch, 70 Electronic control unit (ECU), 80 Ignition switch, 81 Shift lever, 82 Shift position sensor, 83 Accelerator Pedal, 84 accelerator pedal position sensor, 85 brake pedal, 86 brake pedal position sensor, 88 vehicle speed sensor, MG motor.

Claims (1)

An engine capable of outputting power,
A transmission connected to the output shaft of the engine and a drive shaft coupled to the axle;
A motor capable of inputting and outputting power;
A clutch for connecting and releasing the connection between the motor and the output shaft or the drive shaft;
A battery capable of exchanging power with the motor;
A hybrid vehicle comprising:
Control means for controlling the clutch so as to release the clutch when the storage ratio of the battery is within a predetermined range and the operating point of the engine according to the accelerator operation amount is within a predetermined operating range including a fuel efficiency operation line;
A hybrid car with

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