JP2008255941A - Workload control system in work vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a workload control system in a work vehicle equipped with a common rail type engine, capable of preventing a trouble from causing if it is expected that a workload increases in the future and a control in an engine workload performance is thus decreased. <P>SOLUTION: The workload control system in a work vehicle equipped with a common rail type engine includes a workload estimation means 1 for estimating beforehand an increase or a decrease of a workload during a work operation; and a mode setting means 2 for selecting and setting a specific workload estimation mode from among a plurality of workload estimation modes EM from a workload preestimation by the workload estimation means 1. The engine is controlled from the workload estimation mode set by the mode setting means 2. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a work load control device for a work vehicle, and mainly performs engine load control in a work vehicle equipped with a common rail engine by predicting a load variation.

  Conventionally, in a common rail engine, when the common rail pressure is higher than the target pressure, the fuel injection period becomes extremely short, and noise is generated due to combustion accompanied by large heat generation in a short time, which is not preferable in terms of vehicle performance. For this reason, a pressure reducing valve for reducing the common rail pressure is provided on the common rail or the high pressure fuel pipe, or the injector for injecting the high pressure fuel stored in the common rail is opened with a time width shorter than the time required to open the valve. A technique is known in which a common rail pressure is lowered by driving a valve to idle. However, the technique using the pressure reducing valve causes an increase in cost, and the technique in which the injector is idled causes a problem that noise is generated due to high-temperature combustion at the beginning of the pressure reduction.

Therefore, high-temperature combustion prediction means for predicting the occurrence of high-temperature combustion, and combustion slow-down means for slowing down combustion by suppressing fuel injection by the injector when high-temperature combustion is predicted by this high-temperature combustion prediction means Are provided with a control device for controlling the injector in accordance with the operating state of the engine. (For example, see Patent Document 1)
JP 2004-169633 A

  However, a fuel injection control technique is known in which high-temperature combustion is predicted by the high-temperature combustion prediction means, and based on this prediction, fuel injection by the injector is suppressed by the combustion slow-down means to slow down the combustion. However, in a work vehicle equipped with a common rail type diesel engine, there is a problem in that the corresponding control of the engine load performance is lowered when the fluctuation of the load operation during the work is large.

  Accordingly, the present invention is intended to avoid the occurrence of such troubles during engine load control.

  According to the first aspect of the present invention, in a work load control device for a work vehicle equipped with a common rail engine, load predicting means 1 for predicting in advance fluctuations in load during work, and load pre-predicting by the load predicting means 1 And a mode setting means 2 for selecting and setting a specific load prediction mode from a plurality of engine load prediction modes EM, and engine control based on the load prediction mode set by the mode setting means 2 It is set as the structure of the work load control apparatus of the working vehicle characterized by performing.

  With such a configuration, during the work, the load prediction means 1 predicts in advance a change in the future load fluctuation of the work vehicle, and a plurality of engine load prediction modes EM based on the content of the prior prediction of the load fluctuation. Select and set a specific load prediction mode. Then, engine control is performed according to the selected load prediction mode.

  In the invention of claim 2, the engine load prediction modes EM include a sudden load prediction mode P used when at least a sudden load of the engine is predicted to increase, and a sudden increase in the engine load. It has the normal prediction mode Q used when it is not predicted, It is set as the structure of the work load control apparatus of the work vehicle of Claim 1 characterized by the above-mentioned.

  With such a configuration, during work, the load prediction unit 1 predicts in advance the change in the load fluctuation of the work vehicle in the future, and the mode setting unit 2 previously sets the load prediction mode based on the content of the prior prediction. When suddenly excessive load increase is predicted, the mode is changed to the sudden load prediction mode P, and when sudden increase in engine load is not predicted, the mode is changed to the normal prediction mode Q.

  In the first aspect of the invention, as described above, the state change of the future load fluctuation at the time of work is predicted in advance, and the optimum load prediction mode based on the content of the prior prediction is set in advance, so that When the actual load fluctuation occurs, it can be prepared by changing the mode, and the engine load performance corresponding control can be satisfactorily maintained. As a result, it is possible to comprehensively suppress the occurrence of problems such as black smoke discharge and rotation reduction when a load is actually applied to the engine.

  In the invention of claim 2, as described above, a state change of a future load fluctuation is predicted in advance, and when an excessive load is suddenly predicted based on the contents of the prior prediction in advance, a sudden load prediction mode is set. In P, when a sudden increase in engine load is not predicted, by switching the load prediction to the normal prediction mode Q, it is possible to prepare for a state change of an actual load fluctuation that occurs after the fact. Correspondence control can be maintained satisfactorily. Further, it is possible to prevent the occurrence of problems such as black smoke discharge and rotation reduction during engine load control.

Embodiments of the present invention will be described below with reference to the drawings.
As shown in FIG. 2, an outline of an embodiment of a multi-cylinder diesel engine 8 adopting a common rail type (accumulation type fuel injection) will be described with reference to a system diagram. In addition, although the Example of the diesel engine is shown in the present Example, a gasoline engine may be used.

In the common rail type, fuel is supplied to a fuel injection device that injects fuel into each cylinder through a common rail 10 (pressure accumulating chamber) having a required pressure.
The fuel in the fuel tank 11 is sucked into the fuel injection pump 13 driven by the engine 8 through the fuel filter 12 through the suction passage, and the high-pressure fuel pressurized by the injection pump 13 is discharged to the common rail through the discharge passage 14. It is led to 10 and stored.

  The high-pressure fuel in the common rail 10 is supplied to the injectors 17 corresponding to the number of cylinders through the high-pressure fuel supply passages 16, and the injectors 17 are opened for each cylinder based on a command from an engine control unit 18 (hereinafter referred to as ECU). In operation, high-pressure fuel is injected into each combustion chamber of the engine 8, and surplus fuel (return fuel) in each injector 17 is guided to a common return passage 20 by each return passage 19. Returned to the fuel tank 11.

  In addition, a pressure control valve 21 is provided in the fuel injection pump 13 to control the fuel pressure in the common rail 10 (common rail pressure). The pressure control valve 21 receives fuel from the fuel injection pump 13 by a duty signal from the ECU 18. The flow area of the return passage 20 for surplus fuel to the tank 11 is adjusted, and thereby the fuel discharge amount to the common rail 10 side can be adjusted to control the common rail pressure.

  Specifically, the target common rail pressure is set according to the engine operating conditions, and the common rail pressure is feedback-controlled through the pressure control valve 21 so that the common rail pressure detected by the rail pressure sensor 22 matches the target common rail pressure. .

  Conventionally, in a diesel engine, it is known to perform pilot injection that injects a small amount of fuel in a pulse manner prior to main injection, thereby shortening the ignition delay and reducing the so-called knocking noise peculiar to the diesel engine. .

  This pilot injection is performed once or twice before the main injection. However, by using the system of the common rail 10, the state of the pilot injection is changed according to the state of the engine. The generation of white smoke or black smoke due to noise reduction or incomplete combustion can be suppressed.

  As shown in FIG. 3, the ECU 18 of the common rail type diesel engine 8 in an agricultural vehicle or the like has three types of control modes of a traveling mode M1, a normal working mode M2, and a heavy working mode M3 in relation to the rotational speed and the output torque. .

  The traveling mode M1 is used when traveling without farming as droop control in which the output fluctuates due to fluctuations in the rotational speed. For example, when the traveling speed is reduced or stopped by applying a brake, As the traveling load increases, the engine speed decreases, so the traveling speed can be reduced or stopped safely.

  The normal work mode M2 is used when performing normal farm work as isochronous control in which the rotation speed is constant even when the load fluctuates and the output is changed according to the load. Sometimes, when the cultivated land is hard and resistance is applied to the cultivator blade, the combine makes it easy for the operator to control the output and maintain the rotational speed even when the harvest is heavy and the load increases during harvesting operations.

  In the heavy work mode M3, as in the normal work mode M2, the isochronous control that changes the output according to the load at a constant rotation speed even when the load fluctuates, and when the load limit is approached, the rotation speed is increased to increase the output. Control with heavy load control, especially used when farming near the load limit.For example, when plowing with a tractor, engine output even when encountering hard cultivated land Increases beyond the normal limit, so work is not interrupted.

  As described above, the three control modes of the travel mode M1, the normal work mode M2, and the heavy work mode M3 are actually detected by the engine speed and controlled by a command from the ECU 18 based on the change in the engine speed. Is to do.

  As shown in FIG. 4, a tractor T as an agricultural vehicle has a common rail type diesel engine 8 mounted on a chassis 3, a transmission 4 is connected to the engine 8, and a steering is performed rearward from a hood 5 covering the engine 8. A cabin 7 that houses the device 6 a and the cockpit 6 b is connected and provided, and a rotary device 9 is mounted on the rear end of the transmission 4. 15a shows a front wheel and 15b shows a rear wheel.

  In such a tractor T, sensors for detecting the on / off state of the main clutch 23, the raising / lowering position of the raising / lowering lever 24 for raising / lowering the rotary device 9, the shift operation position of the traveling transmission lever 25, etc. are provided. Load prediction means 1 as a load prediction means for predicting load fluctuations in advance, and mode setting for automatically setting the load prediction mode for the future load based on the prior prediction of the load prediction means 1 The mode setting means 2 is provided as means.

  As described above, in the three kinds of control modes of the travel mode M1, the normal work mode M2, and the heavy work mode M3, the engine speed is actually detected, and the engine is instructed by a command from the ECU 18 based on the change in the engine speed. Since control is performed, a reaction delay in engine control may occur. In particular, when a large load is applied suddenly, the engine speed is reduced at a stretch, which hinders work.

  Therefore, as shown in the flowchart of FIG. 1, the load predicting means 1 detects the load fluctuation based on the detected values of each sensor (change in the shift position of the travel shift lever, change in the rotary lift lever, change in the state of the main clutch, etc.). Prior prediction is performed, and the load mode is set by the mode setting means 2 based on the prior prediction. That is, when a plurality of engine load prediction modes EM are stored in the ECU 18 and it is predicted that an excessive load is suddenly applied, the engine control is performed by switching to the sudden load prediction mode P in advance. Then, after a predetermined time has elapsed, control is performed by switching to the normal prediction mode Q that maintains the normal state.

Further, when a sudden increase in engine load is not predicted, the control in the normal prediction mode Q is continued.
Thus, by setting the load mode in advance by the mode setting means 2 based on the prior prediction of the load prediction means 1, the smoke limit is changed from “strict value” in the normal prediction mode to “loose value” in the sudden load prediction mode. By controlling so, the instantaneous maximum fuel injection amount can be increased to prevent the rotation from decreasing. For the increase in black smoke emission due to this increase, the common rail pressure is changed from “low pressure” in the normal prediction mode to “high pressure” in the sudden load prediction mode, and the injection timing is changed from “delay” in the normal prediction mode to the sudden load. By controlling the pilot injection from the “no state” in the normal prediction mode to the “presence state” in the sudden load prediction mode in the “advance (fast)” prediction mode, the black smoke emission and misfire can be improved. become able to.

  As shown in FIGS. 5, 6 and 7, the common rail diesel engine 8 has a multi-cylinder configuration in which a cylinder head 29 is disposed at the top of the cylinder block 28 and an oil pan 30 is disposed at the bottom. The gear case 31 and the radiator fan 32 are disposed at the rear, and the flywheel 33 is disposed at the rear. Reference numeral 34 denotes a variable turbocharger, 35 denotes a crankshaft, 46 denotes an intake manifold, 46a denotes a side wall of the intake manifold, and 47 denotes a glow plug.

  As shown in FIG. 8, an exhaust path 36 on the exhaust side of the variable turbocharger 34 is connected to the upstream side of the turbine 34a and the downstream side of the turbine 34a is connected to the downstream side of the turbine 34a. And an exhaust gas after-treatment device 38 (DOC + DPF) is provided near the turbine 34a side of the exhaust pipe 37, and an intercooler is provided downstream of the compressor 34b of the variable turbocharger 34. The intake path 40 on the intake side is connected via the line 39. In addition, since DOC is an oxidation catalyst and burns the incombustible material chamber in the exhaust gas, it is necessary to consider the arrangement location so that a relatively high temperature gas passes through. Moreover, DPF is a diesel particulate filter and removes PM (particulate matter) in exhaust gas by attaching it.

  An EGR valve 41 for adjusting the EGR rate is arranged on the EGR gas introduction side connecting the EGR path 41 to the exhaust path 36 and connecting the EGR path 41 to the exhaust path 36 and the intake path 40. The EGR valve 42 and the throttle valve 43 of the exhaust pipe 37 are connected to the ECU 18 so as to be electrically controllable.

  In such an action route, as shown in the flowchart of FIG. 9, the load prediction mechanism 1 performs a prior prediction of the load operation at the time of farm work based on the detection value of each sensor, and the EGR rate control mechanism is based on the prior prediction. Even at the start of driving when suddenly excessive load is applied due to 45a, as shown in the diagram of FIG. 10, the high load that immediately decreases the predicted output to the appropriate EGR rate e as soon as the increase in engine load is predicted. Since the EGR control based on the engine load can be performed by starting the side control and then detecting the engine load state, the responsiveness of the control is improved by the prior prediction, and the exhaust gas can be maintained in a good state.

  Further, as shown in FIG. 8, in the operation path of the diesel engine 8, as shown in the flowchart of FIG. Based on this advance prediction, the boost pressure control mechanism 45b can perform variable turbocharging at the time of predicting an increase in engine load, as shown in the diagram of FIG. 12, even at the start of driving when suddenly excessive load is applied. The high load side control for making the inflow amount into the machine 34 variable and immediately increasing the predicted output to the appropriate boost pressure b is started, and then the variable turbo control by the engine load can be performed by detecting the engine load state. Therefore, the responsiveness of the control is improved by prior prediction, and problems such as black smoke discharge, torque fluctuation, and rotation reduction can be prevented.

  Further, in the common rail diesel engine 8, since the time interval between the pilot injection p and the main injection m cannot be shorter than the fixed time required to accumulate the charge for operating the injector 17 with one injector 17 per cylinder, high speed The injection pattern with a high degree of freedom cannot be set due to restrictions as it rotates at.

  For this reason, as shown in the diagram of FIG. 13A, by using one injector 17 per cylinder, the conventional injection pattern in which the time interval between the pilot injection p and the main injection m is fixed is shown in FIG. As shown in the diagram 13 (b), by using two injectors 17 per cylinder, it is possible to realize an injection pattern in which the time interval between the pilot injection p and the main injection m can be freely set without limitation, thereby improving combustion. Leads to. A power source for operating the injector 17 is provided for each injector 17.

  In addition, in the power supply for one injector 17 per cylinder, the time interval between the pilot injection p and the main injection m is limited in time, and the injection pattern is limited as the engine rotates at high speed. From the conventional injection pattern in which the time interval between the pilot injection p and the main injection m is fixed as shown in the diagram of FIG. As shown in the figure, it is possible to realize an injection pattern in which the time interval between the pilot injection p and the main injection m can be freely set without limitation, which is effective in improving combustion.

Conventionally, as shown in FIG. 15, a glow plug 47 for each cylinder is inserted into the lower side of the intake port 29 a of the cylinder head 29 from the lower side of the side wall 46 a of the intake manifold 46 connected to the side of the cylinder head 29. At the time of placement, the side wall 46a is provided with a recess d as a relief for avoiding interference with the glow plug 47, but there is a problem that the air flow is disturbed by the recess d and the air suction efficiency is lowered. (See Figure 5)
For this reason, as shown in FIG. 16, a glow plug 47 is fitted and disposed in the intake manifold 46, and the connection terminal t provided on the side wall 46 a of the intake manifold 46 and the electrode of the glow plug 47 are connected by a conductive bar 48. Thus, the glow plug 47 can be fitted and arranged on the lower side of the intake port 29a without lowering the air intake efficiency, so that combustion can be improved and the intake manifold 46 can be easily assembled. It becomes.

  Further, in the intake port 29a in the cylinder head 29 of the four-valve combustion chamber as shown in FIG. 17, conventionally, as shown in FIG. 18 (a), a helical portion h is provided near the valve v of the intake port 29a. The air is swirled spirally by the portion h so as to flow into the cylinder and form the swirl flow r. However, if the swirl flow r is strengthened for the purpose of improving combustion, the helical portion h This increases the resistance of the intake air and decreases the amount of intake air. In some cases, the combustion may worsen.

  For this reason, as shown in FIG. 18B, by arranging the spiral swirl current plate s in the vicinity of the inlet of the intake port 29a, the swirl flow r can be generated in the intake port 29a. The strong swirl flow r can be formed without reducing the intake air amount, and the combustion can be improved.

  Further, in an engine having a DPF (diesel particulate filter) 50 that collects PM (particulate matter) contained in exhaust gas and performs a regeneration process, as shown in FIG. When the temperature sensor 51 for detecting the temperature of the exhaust gas and the electric wire 52 for measuring the resistance value by the exhaust gas are provided on the outlet side, when the resistance value of the electric wire 52 is large, PM is attached to the electric wire 52. In order to prevent erroneous recognition of the resistance value due to the temperature difference, the resistance value in each temperature range is set as a threshold value. When the difference from the threshold value is equal to or greater than a certain value, it is determined that the DPF 50 needs to be regenerated.

  Further, in an engine having a DPF 50 and a DOC (oxidation catalyst) 53 that collects PM contained in exhaust gas and performs a regeneration process, conventionally, when the exhaust gas is hot, the DOC 53 is not passed using a bypass or the like. However, when a bypass or the like is used, the structure becomes large and it is impossible to mount it in a limited space such as an agricultural work vehicle.

  For this reason, as shown in FIG. 20 (a), a flow path opening / closing valve 53b capable of changing the flow rate of the exhaust gas is provided in the center of the DOC case 53a in which the DOC 53 is housed to minimize the size structurally. The bypass flow path 53c is provided, and in normal cases, the flow path opening / closing valve 53b is closed to control the exhaust gas to pass through the DOC 53. During this control, an appropriate temperature sensor disposed near the inlet of the DOC case 53a When the temperature rise of the exhaust gas is detected by the above, by opening the flow path opening / closing valve 53b and controlling the exhaust gas to pass through the bypass flow path 53c without passing through the DOC 53, as shown in FIG. Overheating can be prevented. The amount of exhaust gas passing through the DOC 53 can be changed by the flow path opening / closing valve 53b to enable arbitrary temperature control.

  Further, in the combine as an agricultural work vehicle, as shown in FIG. 21 (a), along with the input of the firewood discharge switch 54 for discharging the firewood, a command is sent from the ECU 18 by a signal by this input, as shown in FIG. 21 (b). As described above, when the soot is discharged, the post-injection x is performed separately from the pilot injection p and the main injection m, and the exhaust temperature is raised by the post-injection x so that the regeneration of the DPF 50 can be performed periodically.

  In the conventional electronically controlled engine, as shown in FIG. 22, the generation of an angle pulse by the crank wheel 56 rotating in synchronization with the crankshaft 55 is read by the angle sensor 57, and the rotation ratio is ½ of the engine speed. The cam wheel 58, the cam sensor 59, and the ECU 18 are used to discriminate the stroke of each cylinder, and after the determination, fuel injection is started. Therefore, the cylinder cannot be discriminated while the crankshaft 55 rotates twice, and the mechanical control is performed. There was the difficulty that startability was inferior to the engine.

  In order to improve such difficulties, the recognition protrusion k (# 1, # 2, # 3, # 4 corresponding to the top dead center of each cylinder provided in the cam wheel 58 during the stroke determination immediately after the engine is started. ), Which has been the same height as before, is changed for each cylinder and the gap with the cam sensor 59 is changed, so that the output voltage can be differentiated and the stroke can be discriminated, thus improving the startability. Can be made.

  Further, in the conventional electronic control engine, as shown in FIG. 23, a crank wheel 60 that rotates in synchronization with the crankshaft 55 is combined with the number of gear teeth equally distributed according to the number of cylinders and one deformed tooth z. A rotation angle that enables mutual recognition of the strokes determined by detecting the deformed teeth z by the rotation of the crank wheel 60 by the rotation of the crank wheel 60 is necessary, and fuel injection is performed until this confirmation is made. Such a control instruction cannot be performed and the startability is inferior.

  In order to improve such difficulties, the recognition protrusion k corresponding to the top dead center of each cylinder provided in the cam wheel 58 with respect to the deformed tooth z of the crank wheel 60 that recognizes the top dead center of the # 1 cylinder. (# 1, # 2, # 3, # 4) Since the # 1 cylinder and the # 4 cylinder are in phase, the shape of the recognition protrusion k (# 4) is changed to determine the stroke at the start. I was trying to do it.

  However, as shown in FIG. 24 (a), in order to discriminate between the # 1 cylinder and the # 4 cylinder, and the # 2 cylinder and the # 3 cylinder, which are contradictory to each other by the phase of the crankshaft 55, What changes the shape (size in the width direction) of the projections k (# 1 and # 4) and (# 2 and # 3), as shown in FIG. By changing the shape (size in the width direction) for each cylinder, or changing the shape (number of protrusions) of the recognition protrusion k of the cam wheel 58 for each cylinder as shown in FIG. When the first tooth of the recognition protrusion k corresponding to each cylinder is sensed, cylinder discrimination becomes possible, so that startability is improved.

  It can be used for farm vehicles such as tractors and combiners as well as general vehicles.

The flowchart which shows the procedure which switches load mode based on prediction of load operation. The system figure which shows the pressure accumulation type fuel injection diesel engine by a common rail. The diagram which shows the relationship between the engine speed and output torque by three types of control modes. The side view which shows the general | schematic installation state of the whole structure and required action mechanism in a tractor. The side view which shows the whole structure in a common rail type | mold multi-cylinder diesel engine. The top view which shows the whole structure in a common rail type | mold multi-cylinder diesel engine. The rear view which shows the whole structure in a common rail type | mold multi-cylinder diesel engine. The circuit diagram which showed the action | operation path | route of intake / exhaust and EGR centering on a turbocharger. The flowchart which shows the procedure which controls the EGR rate based on prediction of load operation. The diagram which shows the state reduced to a suitable EGR rate at the time of estimating the increase in load. The flowchart which shows the procedure which controls turbo based on prediction of load operation | movement. The diagram which shows the state which increases to a suitable boost pressure at the time of estimating the increase in load. (A) The diagram which shows the state of the injection pattern by one injector per cylinder. (B) The diagram which shows the state of the injection pattern by two injectors per cylinder. (A) The diagram which shows the injection pattern by the power supply for one injector per cylinder. (B) The diagram which shows the injection pattern by the power supply for two injectors per cylinder. The back sectional view showing the wearing state of the glow plug inserted from the intake manifold. The back sectional view showing the wearing state of the glow plug inserted from the intake manifold. The perspective view which shows the arrangement | positioning relationship between the intake port and cylinder in a cylinder head. (A) The perspective view which shows the swirl flow formation state by the valve vicinity helical part of an intake port. (B) The perspective view which shows the swirl flow formation state by the swirl current plate near the inlet of the intake port. The top view which shows the state which provided the electric wire for PM regeneration judgment by resistance value in DPF. (A) The effect | action figure which shows the state which exhaust gas passes through DOC by closing of a bypass channel. (B) The effect | action figure which shows the state which opens a bypass channel and exhaust gas does not pass DOC. (A) Schematic which shows the state which transmits an injection signal through ECU from a soot discharge switch. (B) The diagram which shows the state which performs post injection separately from pilot injection and main injection. FIG. 3 is an operation diagram showing a state of stroke discrimination of each cylinder in an electronically controlled engine. FIG. 3 is an operation diagram showing a state of stroke discrimination of each cylinder in an electronically controlled engine. (A) The top view which shows the shape of each cylinder discrimination cam wheel in an electronically controlled engine. (B) The top view which shows the shape of each cylinder discrimination cam wheel in an electronically controlled engine. (C) The top view which shows the shape of each cylinder discrimination | determination cam wheel in an electronically controlled engine.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Load prediction means 2 Mode setting means P Rapid load prediction mode Q Normal prediction mode EM Engine load prediction mode

Claims (2)

  In a work load control device for a work vehicle equipped with a common rail engine, based on load prediction means (1) for predicting in advance fluctuations in load during work, and load prediction by the load prediction means (1) Mode setting means (2) for selecting and setting a specific load prediction mode from a plurality of engine load prediction modes (EM), and based on the load prediction mode set by the mode setting means (2) And a work load control device for a work vehicle.   The plurality of engine load prediction modes (EM) include a sudden load prediction mode (P) used when at least a sudden load on the engine is predicted to increase, and a case where a sudden increase in the engine load is not predicted. The work load control device for a work vehicle according to claim 1, wherein the work load control device has a normal prediction mode (Q) used for the work vehicle.

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