JP3632509B2 - Internal throttle prevention device for internal combustion engine - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a throttle sticking prevention device for an internal combustion engine that prevents sticking of a throttle valve provided in an intake passage that guides air to a combustion chamber of the internal combustion engine.
[0002]
[Prior art]
In an automobile engine, when the temperature drops, the engine throttle valve may stick. For example, when the intake air temperature is low and the humidity is high during engine warm-up operation, water vapor and fuel in the intake air freeze on the intake passage and the throttle valve, and the throttle valve is fixed.
[0003]
For this reason, for example, in the throttle control device described in Japanese Patent Laid-Open No. 59-188050, it is assumed that an actuator for opening and closing the throttle valve is provided. The throttle valve was swung in the vicinity of the target throttle opening, thereby preventing freezing and sticking of the throttle valve.
[0004]
[Problems to be solved by the invention]
However, in the above conventional throttle control device, only ice adhering to the vicinity of the target throttle opening can be removed, and when the target throttle opening changes greatly, the throttle valve rides on the ice that has not been removed. If the throttle valve rides on the ice that has been frozen and grown, the degree of sticking of the throttle valve increases, and the throttle valve cannot be swung by the driving force of the actuator, causing the engine to overspeed or stop.
[0005]
Therefore, the present invention has been made in view of the above-described conventional problems, and provides a throttle sticking prevention device for an internal combustion engine that can eliminate sticking of the throttle valve even if icing around the throttle valve is advanced. There is to do.
[0006]
[Means for Solving the Problems]
In order to solve the above problems, the present invention provides a throttle sticking prevention device for an internal combustion engine that prevents sticking of a throttle valve provided in an intake passage that guides air to a combustion chamber of the internal combustion engine. A fixing degree determining means for determining whether or not the fixing degree is large; and a vibration control means for increasing the vibration of the intake passage when the fixing degree determining means determines that the fixing degree is large.When the internal combustion engine is started, if it is determined that the degree of fixation is large by the degree-of-adhesion determination means, the vibration control means is configured to extend the period from the initial explosion to the complete explosion in the internal combustion engine. Therefore, the vibration of the intake passage is increased.
[0007]
According to the present invention, when the throttle valve is firmly fixed, the vibration of the intake passage is increased. This vibration eliminates icing of the throttle valve, the sticking of the throttle valve is eliminated, and throttle valve opening / closing control becomes possible.
[0011]
The initial explosion is the combustion that first occurs in any of the cylinders of the internal combustion engine, and the complete explosion is that combustion is continuously generated in all the cylinders of the internal combustion engine. When starting the internal combustion engine, the vibration of the internal combustion engine can be increased by extending the period from the initial explosion to the complete explosion.
[0012]
In one embodiment, after the internal combustion engine is started, when the sticking degree determination means determines that the sticking degree is large, the vibration control means causes the internal combustion engine toFluctuating output torqueThis increases the vibration of the intake passage.
[0013]
After starting the internal combustion engine,Fluctuating output torqueMakeaboutThus, the vibration of the intake passage can be increased.
For example, the engine output torque can be varied by cutting the fuel injection, increasing or decreasing the fuel injection amount, changing the ignition timing of the spark plug, changing the opening / closing timing of the intake / exhaust valve, or changing the EGR amount.
[0014]
In one embodiment, when the vibration of the intake passage is increased by the vibration control means, a shift position changing means for changing a shift position of a transmission connected to the output shaft of the internal combustion engine to a neutral position is provided.
[0015]
When changing the shift position of the transmission connected to the output shaft of the internal combustion engine to the neutral position,Of output torqueThe fluctuation range of the rotation of the internal combustion engine that can be realized by the fluctuation can be increased, and the fluctuation of the output torque of the internal combustion engine is hardly transmitted to the outside.
[0016]
In one embodiment, after the start of the internal combustion engine, when the degree of fixation is determined to be large by the degree of fixation determination means, the vibration control means sets the shift position of the transmission connected to the output shaft of the internal combustion engine. By changing, the vibration of the intake passage is increased.
[0017]
When the shift position of the transmission connected to the output shaft of the internal combustion engine is changed, the rotational state of the transmission changes, thereby increasing the vibration of the intake passage.
[0018]
In one embodiment, the vibration control means increases the vibration of the intake passage by changing the shift position of the transmission connected to the output shaft of the internal combustion engine to the high geared side.
[0019]
In one embodiment, the vibration control means increases the vibration of the intake passage by changing the shift position of a transmission connected to the output shaft of the internal combustion engine to the low geared side.
In one embodiment, the warm-up determination unit that determines whether or not the intake passage is warmed up, and the opening degree of the throttle valve is determined until the warm-up determination unit determines that the intake passage is warmed up. Prohibiting means for prohibiting entering the vicinity of the opening of the throttle valve when the sticking degree is judged to be large by the sticking degree judging means is provided.
Here, once the sticking occurs, the opening of the throttle valve enters the vicinity of the opening of the throttle valve when the sticking occurs until the intake passage is warmed up and cannot be stuck. This prohibits the throttle valve from sticking repeatedly.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the accompanying drawings.
[0021]
FIG. 1 is a schematic configuration diagram showing an embodiment of the throttle sticking prevention device of the present invention. In FIG. 1, a throttle valve 4 is provided in an internal combustion engine (hereinafter referred to as an engine) 1 of an automobile. The throttle valve 4 has its opening degree adjusted by a throttle actuator 5 as an electronic control actuator while its opening degree is detected by a throttle sensor 6, thereby adjusting the amount of air taken into the engine 1.
[0022]
A piston 9 that reciprocates in the vertical direction in the figure is disposed in a cylinder 8 that constitutes a cylinder of the engine 1, and the piston 9 is connected to a crankshaft 11 via a connecting rod 10. A combustion chamber 13 defined by a cylinder 8 and a cylinder head 12 is formed above the piston 9. The combustion chamber 13 communicates with the intake pipe 2 and the exhaust pipe 3 via the intake valve 14 and the exhaust valve 15.
[0023]
The intake port 17 of the engine 1 is provided with an electromagnetically driven injector 18, and fuel (gasoline) is supplied to the injector 18 from a fuel tank (not shown). The air supplied from the upstream side of the intake pipe 2 and the injected fuel supplied by the injector 18 are mixed in the intake port 17, and the mixture is in the combustion chamber 13 (in the cylinder 8) as the intake valve 14 opens. Flow into. Then, the air-fuel mixture flowing into the combustion chamber 13 is compressed therein, and is ignited and explodes when an ignition spark is emitted from the spark plug 19. The engine 1 obtains rotational torque by this explosion. The burned gas is discharged to the exhaust pipe 3 through the exhaust valve 15 as exhaust gas.
[0024]
The cylinder 8 (water jacket) is provided with a water temperature sensor 21 for detecting the engine water temperature. Furthermore, a reference position sensor 22 that outputs a pulse signal at every 720 ° CA (crank angle) according to the rotation state and a pulse signal at every constant crank angle (for example, 30 ° CA) are output to the crankshaft 11. A rotation speed sensor 23 is provided.
[0025]
Further, an air flow meter 24 and an intake air temperature sensor 32 for detecting the intake air amount are disposed upstream of the intake pipe 2. The air flow meter 24 is of a hot wire type (hot wire type), for example. The accelerator pedal 25 that is depressed by the driver is provided with an accelerator sensor 26 for detecting the amount of depression of the accelerator pedal 25.
[0026]
The automatic transmission 29 changes the gear ratio in the range of 1st speed (lowest speed) to 5th speed (highest speed) according to the load of the engine 1 and the vehicle speed, etc., and changes the rotational speed and torque of the crankshaft 11 of the engine 1. Convert and output. The automatic transmission 29 also includes a fluid coupling (torque converter) that transmits the torque of the crankshaft 11 and a lockup mechanism that directly connects the input / output shaft of the fluid coupling. The shift sensor 28 detects the shift position of the automatic transmission 29.
[0027]
The cylinder head 12 is provided with a variable valve timing mechanism 33. The variable valve timing mechanism 33 adjusts the opening / closing timing of the intake valve 14 and the opening / closing timing of the exhaust valve 15 in response to the control of the ECU 30.
[0028]
On the other hand, the ECU 30 is mainly configured by a microcomputer including a known CPU, ROM, RAM, I / O circuit and the like. The ECU 30 inputs detection signals from the water temperature sensor 21, the reference position sensor 22, the rotation speed sensor 23, the air flow meter 24, the accelerator sensor 26, the shift sensor 28, and the intake air temperature sensor 32, and based on these various detection signals. Engine water temperature, crank angle, engine speed, intake air volume, accelerator opening, shift position, and intake air temperature are detected.
[0029]
Further, the ECU 30 calculates a fuel injection amount (fuel injection time), an ignition timing, a target throttle opening, a valve timing, a shift position, and the like based on various detection outputs from the sensor group, Ignition by the spark plug 19, opening of the throttle valve 4 by the throttle actuator 5, opening / closing timing of the intake / exhaust valve by the variable valve timing mechanism 27, and shift position of the automatic transmission 29 are controlled.
[0030]
In the apparatus having such a configuration, the degree of sticking of the throttle valve 4 due to icing is determined. When the degree of sticking is large, the throttle valve 4 is stuck by eliminating vibration by generating vibration in the intake pipe 2. Has been eliminated. Next, vibration control for eliminating the sticking of the throttle valve 4 will be described with reference to the flowcharts shown in FIGS.
[0031]
The processes of the flowcharts shown in FIGS. 2 and 3 are repeated, for example, every 4 msec. Each time, the ECU 30 increments the count value cti by 1 (step 101), determines whether or not the count value cti has reached 15 (step 102), and when the count value cti reaches 15 (step 102). In step 102, Yes), the count value cti is returned to 0 (step 103). That is, every 4 msec, the count value cti is incremented one by one in the range of 0 to 15.
[0032]
When the ignition key 31 is turned on and the starter motor (not shown) is operating, the ECU 30 determines that the engine 1 is in the start mode when the engine speed is 400 rpm or less (step 104, Yes). Then, it is determined whether or not the sticking determination flag xkochak is off (step 105). At this time, since it is immediately after the start of the starter motor, the sticking determination flag xkochak is set to OFF (step 105, Yes), and the ECU 30 determines whether or not the count value cti is less than 8, that is, the count value cti. Is the first half or the second half of the cycle T in which the number of steps is repeatedly incremented from 0 to 15 (step 106).
[0033]
If it is the first half of the cycle T (step 106, Yes), the ECU 30 sets the temporary target of the throttle valve 4 corresponding to the coolant temperature thw detected by the coolant temperature sensor 21 based on a preset function F_hi (thw). An opening t_tangle is obtained (step 107).
[0034]
If the second half of the cycle T (step 106, No), the ECU 30 sets the throttle valve 4 corresponding to the coolant temperature thw detected by the water temperature sensor 21 based on a preset function F_low (thw). A temporary target opening t_tangle is obtained (step 110).
[0035]
Then, the ECU 30 determines whether or not the count value cti is equal to any of 0, 1, 8, and 9, that is, immediately after the start of the first half of the cycle T or immediately after the start of the second half (step 108). If it is immediately after the start of the first half of T or immediately after the start of the second half (step 108, No), the target opening degree of the throttle valve 4 is set to the temporary target opening t_tangle without performing the processing of steps 111 to 115 (step 109). ). Thereafter, the ECU 30 controls the throttle actuator 5 so as to adjust the opening of the throttle valve 4 to the target opening “angle”.
[0036]
Therefore, in the first half of the cycle T, the target opening degree based on the function F_hi (thw) is set, and in the second half of the cycle T, the target opening degree tangent is set based on the function F_low (thw). The throttle valve 4 is swung toward two different target opening degrees in the first half and the second half of the cycle T.
[0037]
Further, the count value cti is not equal to any of 0, 1, 8, and 9, that is, it is not immediately after the start of the drive control of the throttle actuator 5 for adjusting the opening of the throttle valve 4 to the target opening angle (step). 108, Yes), the process proceeds to step 111 to determine whether or not the throttle valve 4 is fixed.
[0038]
In step 111, the ECU 30 obtains the drive current duty of the throttle actuator 5 detected by an ammeter (not shown), and the cooling water detected by the water temperature sensor 21 based on a preset function F_1 (thw). A drive current threshold value corresponding to the water temperature thw is obtained, and it is determined whether or not the absolute value of the drive current duty is larger than the drive current threshold value. Further, the ECU 30 obtains the opening change amount dlta of the actual opening ta of the throttle valve 4 detected by the throttle sensor 6 and detects it by the water temperature sensor 21 based on a preset function F_2 (thw). Then, an opening degree change threshold value corresponding to the coolant temperature thw is obtained, and it is determined whether or not the opening degree change amount dlta is less than the opening degree change threshold value. Further, the ECU 30 determines whether or not the absolute value | t_tangle−ta | of the difference between the current temporary target opening t_tangle and the actual opening ta of the throttle valve 4 detected by the throttle sensor 6 is larger than a preset constant K_3. Determine whether.
[0039]
Here, the driving current duty is larger than the driving current threshold, the opening change amount dlta is not less than the opening change amount threshold, or the absolute value | t_tangle-ta | of the difference is larger than the constant K_3. If not (No at Step 111), it is determined that the throttle valve 4 is not fixed, and the ECU 30 sets the fixed count value cko to 0 (Step 112), and then proceeds to Step 109.
[0040]
If drive current duty is larger than the drive current threshold, opening change amount dlta is less than the opening change amount threshold, and the absolute value of the difference | t_tangle-ta | is larger than constant K_3. (Step 111, Yes), it is determined that the throttle valve 4 is fixed, and the ECU 30 advances the fixed count value cko by one (step 113). If the fixed count value cko is less than 3 (step 113) 114, No), and moves to Step 109.
[0041]
Further, when the process of step 101 is repeated and the sticking count value cko is stepped up and becomes larger than 3 (step 114, Yes), the ECU 30 sets the sticking determination flag xkochak to on and the throttle valve at this time The actual opening ta of 4 is set as the fixing opening tako (step 115), and the routine proceeds to step 109.
[0042]
That is, in steps 101 to 115, control for swinging the throttle valve 4 is performed prior to the start of the engine 1. With this swing control, the drive current duty of the throttle actuator 5 is large and the throttle valve 4 is driven. When the actual opening ta of the throttle valve 4 does not change significantly and the actual opening ta of the throttle valve 4 deviates significantly from the temporary target opening t_tangle, it is considered that the throttle valve 4 is fixed. If this state continues until the sticking count value cko becomes larger than 3, the sticking determination flag xkochak is set to ON, and the actual opening degree ta of the throttle valve 4 at this time is set as the sticking opening degree tako.
[0043]
The functions F_hi (thw) and the function F_low (thw) in steps 107 and 110 indicate different temporary target openings t_tangle, and for example, open / close the throttle valve 4 as the coolant temperature thw decreases. It represents a characteristic that the temporary target opening t_tangle of the throttle valve 4 is gradually increased as the cooling water temperature thw is lowered in anticipation of an increase in operating resistance.
[0044]
Further, the function F_1 (thw) in step 111 predicts that the resistance of the opening / closing operation of the throttle valve 4 increases as the coolant temperature thw decreases, for example, and the drive current as the coolant temperature thw decreases. It represents the characteristic of increasing the threshold value. For the same reason, the function F_2 (thw) in step 111 represents the characteristic that the opening change amount threshold value is decreased as the coolant temperature thw decreases.
[0045]
Next, for example, it is assumed that the throttle valve 4 is stuck and the sticking determination flag xkochak is turned on in step 115. In this state, when the processing from step 101 is repeated and the start mode is continued (step 104, Yes), it is determined that the sticking determination flag xkochak is on (step 105, No). In this case, the ECU 30 sets the temporary target opening corresponding to the coolant temperature thw detected by the water temperature sensor 21 and the accelerator opening pedal detected by the accelerator sensor 26 based on a preset function F_st (thw, pedal). The degree t_tangle is obtained (step 116).
[0046]
Thereafter, the ECU 30 obtains an open side fixing opening threshold value corresponding to the coolant temperature thw detected by the water temperature sensor 21 based on a preset function F_or (thw), and the fixing set in step 115. It is determined whether or not the opening degree tako is larger than the open side stuck opening degree threshold value, that is, whether or not the stuck opening degree tako is so large that the engine 1 overruns (excessive engine speed) (step). 117).
[0047]
If the fixed opening degree tako is so large that the engine 1 is overrun (step 117, Yes), the ECU 30 corrects the normal fuel injection amount in the start mode obtained based on a preset function F_ust (thw). In other words, based on the function F_ust (thw), the normal fuel injection amount corresponding to the coolant temperature thw detected by the water temperature sensor 21 is obtained, and further corrected by multiplying the normal fuel injection amount by 0.7. A fuel injection amount tau is obtained (step 118). The ECU 30 controls the fuel injection by the injector 18 and supplies the corrected fuel injection amount tau from the intake pipe 2 to the combustion chamber 13. The corrected fuel injection amount tau is suppressed to a small amount so that the engine 1 does not overrun.
[0048]
Subsequently, the ECU 30 compares the temporary target opening t_tangle obtained in step 116 with a difference (tako-K_1) obtained by subtracting a preset value K_1 from the fixed opening tako (tako-K_1), and the temporary target opening t_tangle is different (tako). It is determined whether it is larger than -K_1) (step 119). If it is larger (step 119, Yes), the ECU 30 updates the temporary target opening t_tangle to the opening of the difference (tako-K_1) sufficiently separated from the fixed opening tako (step 120), and then the throttle valve. 4 is set to the temporary target opening t_tangle (step 109). On the other hand, if it is not larger (step 119, No), the temporary target opening t_tangle is sufficiently far from the fixed opening tako, so that the ECU 30 does not update the temporary target opening t_tangle and updates the target opening of the throttle valve 4. The degree title is set to the temporary target opening t_tangle (step 109). Thereafter, the ECU 30 controls the throttle actuator 5 so as to adjust the opening of the throttle valve 4 to the target opening “angle”.
[0049]
That is, in the processing of steps 117 to 120, when the fixed opening degree tako is large enough to cause overrun of the engine 1, a fuel injection amount tau sufficiently smaller than the normal fuel injection amount in the start mode is obtained. The fuel injection amount tau is supplied from the injector 18 to prevent the engine 1 from overrun. Further, the temporary target opening t_tangle is set sufficiently away from the fixing opening tako. For this reason, even if the sticking of the throttle valve 4 is eliminated and the throttle valve 4 can be opened and closed, the opening of the throttle valve 4 is not immediately set in the vicinity of the sticking opening tako, and the throttle valve 4 is stuck. It does not adhere again in the vicinity of the opening tako.
[0050]
If the fixing opening tako is not so large that the engine 1 is overrun (step 117, No), the ECU 30 detects the coolant temperature detected by the coolant temperature sensor 21 based on a preset function F_ust (thw). A threshold value for closing side sticking opening corresponding to thw is obtained, and whether or not the sticking opening degree tako is smaller than the threshold value for closing side sticking opening, that is, whether the sticking opening degree tako is so small that the engine 1 is stopped. It is determined whether or not (step 121).
[0051]
If the fixed opening degree tako is so small that the engine 1 stops (step 121, Yes), the ECU 30 adds the provisional target opening degree t_tangle obtained in step 116 to the fixed opening degree tako plus a preset value K_2. Compared with (tako + K_2), it is determined whether or not the temporary target opening t_tangle is smaller than the sum (tako + K_2), that is, whether or not the temporary target opening t_tangle is in the vicinity of the fixed opening tako (step 122). If the temporary target opening t_tangle is in the vicinity of the fixed opening tako (step 121, Yes), the ECU 30 updates the temporary target opening t_tangle to the sum (tako + K_2) (step 123), and then the throttle valve 4 The target opening degree is set to the temporary target opening t_tangle (step 109). Further, the sticking opening degree tako is not so small that the engine 1 is stopped (No in Step 121), and even if the sticking opening degree tako is so small, the temporary target opening degree t_tangle is not in the vicinity of the sticking opening degree tako ( In step 122, No), the ECU 30 sets the target opening degree of the throttle valve 4 to the temporary target opening degree t_tangle without updating the temporary target opening degree t_tangle (step 109). Thereafter, the ECU 30 controls the throttle actuator 5 so as to adjust the opening of the throttle valve 4 to the target opening “angle”.
[0052]
That is, in the processing of steps 121 to 123, when the fixed opening degree tako is small enough to cause the engine 1 to stop, the temporary target opening degree t_tangle is set sufficiently away from the fixed opening degree tako. For this reason, even if the sticking of the throttle valve 4 is eliminated and the throttle valve 4 can be opened and closed, the opening of the throttle valve 4 is not immediately set in the vicinity of the sticking opening tako, and the throttle valve 4 is stuck. It does not adhere again in the vicinity of the opening tako.
[0053]
Next, while the processing from step 101 is repeated, an explosion occurs in any one of the plurality of cylinders of the engine 1 (hereinafter referred to as the first explosion), and when the rotational speed of the engine 1 exceeds 400 rpm, the start mode Is determined (No in Step 104), the process proceeds to Step 124 in order to normally operate the engine 1.
[0054]
First, the ECU 30 is detected by the accelerator opening degree pedal detected by the accelerator sensor 26, the shift position sft detected by the shift sensor 28, and the water temperature sensor 21 based on a preset function F_afs (pedal, sft, thw). The temporary target opening t_tangle corresponding to the coolant temperature thw is obtained. Further, the ECU 30 obtains the intake air amount ga detected by the air flow meter 24 and the air-fuel ratio feedback correction value faf obtained by the calculation based on a preset function F_ast (ga, faf, kg, krichx). The temporary target fuel injection amount t_tau corresponding to the learning value kg and various increase correction values krichx obtained by calculation is obtained. Further, the ECU 30 determines a target opening degree of the throttle valve 4 based on a preset function F_sft (angle, ne, spd, thw), an engine rotational speed ne detected by the rotational speed sensor 23, and an engine rotational speed ne. A temporary target shift position t_sft of the automatic transmission 29 corresponding to the vehicle speed spd calculated from the reduction ratio of the current shift position and the coolant temperature thw detected by the water temperature sensor 21 is obtained (step 124).
[0055]
Thereafter, the ECU 30 determines whether or not the sticking determination flag xkochak is set to ON (step 125). For example, if the sticking determination flag xkochak is turned on in step 115 (step 125, Yes), the ECU 30 determines that the sticking opening degree tako is smaller than the closing side sticking opening degree threshold as in steps 121 and 122. Further, it is determined whether or not the temporary target opening t_tangle obtained in step 124 is in the vicinity of the fixing opening tako (step 126).
[0056]
If the sticking opening degree tako is smaller than the closing side sticking opening degree threshold value and the temporary target opening degree t_tangle is in the vicinity of the sticking opening degree tako (step 126, Yes) as the engine 1 stops, the ECU 30 Based on the set function F_tqd (ga, ne, t_tangle, tako + K_2), the intake air amount ga detected by the air flow meter 24, the engine speed ne detected by the speed sensor 23, and the temporary target obtained in step 124 An ignition timing aop corresponding to the opening t_tangle and the sum (tako + K_2) obtained by the calculation is obtained, and ignition by the spark plug 19 is performed at the ignition timing aop. Further, the ECU 30 updates the temporary target opening t_tangle to the sum (tako + K_2) (step 127), and then proceeds to step 130, similarly to step 123.
[0057]
Here, by the steps 126 and 127, the temporary target opening t_tangle is limited to a sum (tako + K_2) or larger than the value obtained in the step 124. Therefore, as will be described later, even if the throttle valve 4 is fixed due to periodic vibration of the engine 1 and the throttle valve 4 can be opened and closed, the opening of the throttle valve 4 is immediately close to the fixed opening tako. Therefore, there is no risk that the throttle valve 4 will stick again in the vicinity of the sticking opening degree tako. However, since the value obtained in step 124 corresponds to the accelerator opening pedal indicated by the driver, when the temporary target opening t_tangle is limited to a sum (tako + K_2) larger than this value, the throttle valve The actual opening ta of 4 is larger than the opening intended by the driver. This means that the driver causes an unexpected increase in the output torque of the engine 1. The ignition timing aop determined in step 127 is for suppressing an unexpected increase in the output torque of the engine 1, and the ignition plug 19 is ignited at the ignition timing aop. Even if the opening is limited to a sum (tako + K_2) larger than the value obtained in step 124, the output torque of the engine 1 can be made to correspond to the accelerator opening pedal.
[0058]
For example, as shown in the graph of FIG. 4, the actual opening ta of the throttle valve 4 should follow the accelerator opening pedal, but when the throttle valve 4 is fixed at time t1, the actual opening ta of the throttle valve 4 is reduced. It will not follow the accelerator opening pedal. At this time, vibration of the engine 1 is periodically generated. When the sticking of the throttle valve 4 is canceled at the time point t2 due to the vibration of the engine 1, the actual opening degree ta of the throttle valve 4 again follows the accelerator opening degree pedal. At this time, since the temporary target opening t_tagle of the throttle valve 4 is limited to the sum (tako + K_2) or more, the actual opening ta of the throttle valve 4 is limited to the sum (tako + K_2) or more, and the actual opening ta of the throttle valve 4 is There is no risk of the throttle valve 4 being fixed again in the vicinity of the fixing opening tako because the throttle valve 4 is not adjusted in the vicinity of the fixing opening tako. In addition, the output torque of the engine 1 should be reduced corresponding to the accelerator opening degree pedal at the time t3 to t4, but the actual opening degree ta of the throttle valve 4 is limited to the sum (tako + K_2) or more. Instead, the ignition timing aop by the spark plug 19 is changed, whereby the output torque of the engine 1 is made to correspond to the accelerator pedal angle pedal.
[0059]
Even if the opening / closing timing of the intake valve 14 and the opening / closing timing of the exhaust valve 15 are changed by controlling the valve timing variable mechanism 33 instead of changing the ignition timing aop by the spark plug 19, the output torque of the engine 1 is reduced. It is possible to correspond to the accelerator opening degree pedal.
[0060]
Next, if the fixing opening tako is not small enough to stop the engine 1 or if the temporary target opening t_tangle is not near the fixing opening tako (step 126, No), the ECU 30 is the same as steps 117 and 119. In addition, it is determined whether the fixed opening degree tako is so large that the engine 1 is overrun, and the temporary target opening degree t_tangle obtained in step 124 is larger than the difference (tako-K_1) (step 128). If so (No at step 128), the process proceeds to step 130. Further, if the fixed opening degree tako is larger as the engine 1 is overrun and the temporary target opening degree t_tangle is larger than the difference (tako-K_1) (step 128, Yes), the temporary target opening degree is the same as in step 120. After t_tangle is updated to an opening sufficiently separated from the fixing opening tako (step 129), the process proceeds to step 130.
[0061]
For example, as shown in the graph of FIG. 5, when the throttle valve 4 is fixed at time t1, the actual opening ta of the throttle valve 4 does not follow the accelerator opening pedal. At this time, vibration of the engine 1 is periodically generated. When the sticking of the throttle valve 4 is canceled at the time point t2, the actual opening degree ta of the throttle valve 4 follows the accelerator opening degree pedal again. At this time, since the temporary target opening t_tangle of the throttle valve 4 is limited to the difference (tako-K_1) or less, the actual opening ta of the throttle valve 4 is limited to the difference (tako-K_1) or less, and the actual throttle valve 4 The opening degree ta is not adjusted in the vicinity of the fixing opening degree tako, and there is no risk that the throttle valve 4 is fixed again in the vicinity of the fixing opening degree tako.
[0062]
Next, in step 130, the ECU 30 obtains the drive current duty of the throttle actuator 5 and determines a preset function F_1 (thw) in order to determine whether or not the throttle valve 4 is fixed as in step 111. ) To determine the drive current threshold value corresponding to the coolant temperature thw, and determine whether the absolute value of the drive current duty is greater than the drive current threshold value. Further, the ECU 30 obtains an opening change amount dlta of the actual opening ta of the throttle valve 4 and calculates an opening change amount corresponding to the coolant temperature thw based on a preset function F_2 (thw). A threshold value is obtained, and it is determined whether or not the opening change amount dlta is less than the opening change amount threshold value. Further, the ECU 30 determines whether or not the absolute value | t_tangle-ta | of the difference between the current temporary target opening t_tangle and the actual opening ta of the throttle valve 4 is larger than a preset constant K_3.
[0063]
Again, if the throttle valve 4 is fixed, the ECU 30 determines that the drive current duty is larger than the drive current threshold, the opening change amount dlta is less than the opening change amount threshold, and an absolute value. It is determined that | t_tangle-ta | is larger than the constant K_3 (step 130, Yes), the sticking count value cko is incremented by 1, and the first remainder amari_low obtained by dividing the sticking count value cko by 10 and the sticking count value A second remainder amari_hi obtained by dividing cko by 50 is obtained (step 138). Since the cycle of this flowchart is 4 msec, the first remainder amari_low is incremented by 1 in a range of 0 to 9 every 4 msec, and the second remainder amari_hi is incremented by 1 in a range of 0 to 49 every 4 msec. Is done.
[0064]
Thereafter, the ECU 30 determines whether or not the first remainder amari_low is 3 (step 139).
[0065]
Immediately after it is determined in step 130 that the throttle valve 4 is fixed, the first surplus amari_low is less than 3 (No in step 139), so the ECU 30 determines the fuel injection amount tau in step 124. After setting the temporary target fuel injection amount t_tau (step 140), the fuel injection by the injector 18 is controlled to supply the fuel of the fuel injection amount tau from the intake pipe 2 to the combustion chamber 13.
[0066]
Subsequently, the ECU 30 determines whether or not the second remainder amari_hi is greater than 10 and less than 30 (step 141). Similarly to the first remainder amari_low, since the second remainder amari_hi is less than 10 (step 141, No), the ECU 30 has a second remainder amari_hi of 30 or more and the first remainder amari_low is 2 or 3. Whether the engine speed ne detected by the rotation speed sensor 23 is less than a preset threshold value K_4 and the shift position sft detected by the shift sensor 28 is in the range from the first speed to the fifth speed. Is determined (step 142). At this time, since the second remainder amari_hi is less than 10 (step 142, No), the ECU 30 sets the target shift position stf of the automatic transmission 29 to the temporary target shift position t_sft obtained in step 124 ( Step 136) The automatic transmission 29 is controlled to set the actual shift position to the target shift position t_sft. Further, the ECU 30 sets the target opening degree tag of the throttle valve 4 to the temporary target opening degree t_tangle obtained in step 124 (step 137), and controls the throttle actuator 5 to control the opening degree of the throttle valve 4. The target opening degree is adjusted.
[0067]
Therefore, even if it is determined in step 130 that the throttle valve 4 is fixed, immediately after that, the temporary target fuel injection amount t_tau, the temporary target shift position t_sft and the temporary target opening t_tangle obtained in step 124 are the fuel. The injection amount tau, the target shift position t_sft, and the target opening degree are set (steps 140, 136, 137).
[0068]
Next, when the process from step 101 is repeated and the sticking count value cko is incremented and the first remainder amari_low becomes 3 (step 139, Yes), the ECU 30 sets the fuel injection amount tau to 0, and The actual opening ta of the throttle valve 4 detected by the throttle sensor 6 is set as the fixed opening tako, the fixed determination flag xkochak is set to ON, and the normal count value csei is initialized to 0 (step 143).
[0069]
Here, if the fuel injection amount tau is set to 0, the fuel injection amount by the injector 18 becomes 0. Therefore, the combustion and output torque of the engine 1 fluctuate, the engine 1 vibrates greatly, and the throttle valve 4 is stuck. Is resolved.
[0070]
Subsequently, the ECU 30 determines whether or not the second remainder amari_hi is 10 or less and the shift position sft detected by the shift sensor 28 is in the range from the first speed to the fifth speed (step 144).
[0071]
For example, if it is immediately after it is determined in step 104 that the engine is not in the start mode, the second remainder amari_hi is 10 or less, and the shift position sft detected by the shift sensor 28 is 0 speed (hereinafter referred to as neutral). (Step 144, No). Since the second remainder amari_hi is 10 or less (step 141, No) (step 142, No), the ECU 30 determines the target shift position stf of the automatic transmission 29 as the temporary target shift position t_sft (step 124). (Neutral immediately after the start) (step 136), the target opening degree of the throttle valve 4 is set to the temporary target opening t_tangle obtained in step 124 (step 137), and the throttle actuator 5 is driven and controlled. To adjust the opening of the throttle valve 4 to the target opening angle.
[0072]
Therefore, immediately after it is determined in step 104 that the engine is not in the start mode, if the sticking determination flag xkochak is turned on in step 143, the fuel injection by the injector 18 is performed while the shift position of the automatic transmission 29 is kept neutral. The engine 1 is vibrated greatly, and the throttle valve 4 is not fixed. In particular, immediately after it is determined that the engine is not in the start mode, even if the first explosion occurs, the complete explosion (a state in which all the cylinders of the engine 1 are continuously combusting) does not result in the fuel injection. When is cut, the period from the first explosion to the complete explosion is extended, and the vibration of the engine 1 can be effectively generated.
[0073]
On the other hand, not only immediately after it is determined in step 104 that the engine is not in the start mode, but also in the normal operation state of the engine 1, if the throttle valve 4 is stuck and this sticking continues, the sticking determination flag in step 143. xkochak is turned on. At this time, if the second remainder amari_hi is 10 or less and the shift position sft detected by the shift sensor 28 is in the range from the first speed to the fifth speed (step 144, Yes), the ECU 30 After setting the 29 target shift position stf to the fifth speed, the automatic transmission 29 is controlled to set the actual shift position to the fifth speed. Further, the ECU 30 releases the lock-up so that the torque of the input shaft of the fluid coupling is transmitted to the output shaft via the fluid coupling (step 145). Thus, if the shift position of the automatic transmission 29 is set to the fifth speed and the lockup of the fluid coupling is released, even if the output torque of the engine 1 fluctuates, the fluctuation of the output torque affects the driving wheels of the automobile. Because it is alleviated, there is no discomfort to the passengers of the car.
[0074]
That is, when the first remainder amari_low becomes 3, the sticking determination flag xkochak is set to ON, the actual opening ta of the throttle valve 4 at this time is set as the sticking opening tako, and the fuel injection is cut to thereby cut the engine 1. The vibration of the throttle valve 4 is eliminated, and the sticking of the throttle valve 4 is eliminated. At this time, immediately after it is determined that the engine is not in the start mode, and even if the first explosion has occurred, the period from the first explosion to the complete explosion is extended, and the vibration of the engine 1 is reduced. It can be generated effectively. Further, in the state of normal operation of the engine 1, if the second remainder amari_hi is 10 or less and the shift position sft is in the range from the first speed to the fifth speed, the shift position of the automatic transmission 29 is set to the fifth speed, Further, by releasing the lock-up of the fluid coupling, the fluctuation of the output torque of the engine 1 is made difficult to be detected by the vehicle occupant.
[0075]
Next, even if the engine 1 is vibrated greatly in step 143, the sticking of the throttle valve 4 is not eliminated, and if the processing in steps 138 to 144 is repeated, the first surplus amari_low is repeated until it becomes 3. The second remainder amari_hi is either 13 or 23 (step 144, No) (step 141, Yes). At this time, the ECU 30 sets the target shift position stf of the automatic transmission 29 to neutral and then controls the automatic transmission 29 to set the actual shift position to neutral (step 146). Then, the target opening degree of the throttle valve 4 is set to the temporary target opening t_tangle obtained in step 124 (step 137), and the throttle actuator 5 is driven to control the opening degree of the throttle valve 4 to the target opening degree. Adjust to tangle.
[0076]
Therefore, even if the engine 1 is caused to vibrate periodically by cutting the fuel injection, the sticking of the throttle valve 4 is not eliminated, and if the second remainder amari_hi becomes 13 or 23 in this state, Set the shift position of to neutral. Since the rotational fluctuation range of the engine 1 can be increased also by changing the shift position, vibration of the engine 1 can be effectively generated. Further, when the actual shift position is set to neutral, the output torque of the engine 1 is not transmitted to the driving wheels of the automobile, so that even if the output torque fluctuates, there is no need to give discomfort to the passengers of the automobile.
[0077]
Further, even if the engine 1 is vibrated greatly in step 143, the sticking of the throttle valve 4 is not eliminated, and if the processing in steps 138 to 144 is repeated, the first surplus amari_low is repeated until it reaches 3, Since the remainder of two amari_hi is either 33 or 43 (step 144, No) (step 141, No), the routine proceeds to step 142. Here, the ECU 30 has the second remainder amari_hi of 30 or more, the first remainder amari_low is 2 or 3, and the engine speed ne detected by the speed sensor 23 is less than the threshold value K_4. When it is determined that the shift position sft detected by the shift sensor 28 is in the range from the first speed to the fifth speed (step 142, Yes), the temporary target shift obtained in step 124 for the target shift position stf of the automatic transmission 29. After setting the shift position lower than the position t_sft by the first speed (step 147), the automatic transmission 29 is controlled to set the actual shift position to the target shift position stf.
[0078]
Therefore, even if the engine 1 is caused to vibrate periodically by cutting the fuel injection, the sticking of the throttle valve 4 is not eliminated, and if the second remainder amari_hi becomes either 33 or 43 in this state, The actual shift position is controlled by controlling the automatic transmission 29 on condition that the rotational speed ne is less than the threshold value K_4 and the shift position sft of the automatic transmission 29 is in the range from the first speed to the fifth speed. Lower by 1st gear. Due to the change in the shift position, a large vibration is generated in the engine 1, and this vibration and the vibration due to the cut of fuel injection are synergistically generated to generate a large vibration in the engine 1 and the sticking of the throttle valve 4 is eliminated.
[0079]
Here, on the condition that the engine speed ne is less than the threshold value K_4, the actual shift position is lowered by the first speed. This is because when the engine speed ne is a high speed, This is because if the shift position is lowered carelessly, the passengers of the automobile are uncomfortable.
[0080]
Further, the first surplus amari_low is not 3 (No in Step 139), the fuel injection amount tau is set to the temporary target fuel injection amount t_tau obtained in Step 124 (Step 140), and the second surplus amari_hi is greater than 10. When entering the range of less than 30 (step 141, Yes), the shift position of the automatic transmission 29 is set to neutral (step 146). Also in this case, since the load of the engine 1 changes, the output torque of the engine 1 fluctuates, the engine 1 vibrates greatly, and the sticking of the throttle valve 4 is eliminated.
[0081]
Next, if the throttle valve 4 is not fixed, the throttle valve 4 is normally opened and closed by the throttle actuator 5, the drive current duty is larger than the drive current threshold, or the opening change amount dlta is opened. Is not less than the threshold value, or the absolute value | t_tangle-ta | is not larger than the constant K_3 (No in step 130). In this case, the ECU 30 initializes the sticking count value cko, the first surplus amari_low, and the second surplus amari_hi to 0, and sets the fuel injection amount tau to the temporary target fuel injection amount t_tau obtained in step 124 (step). 131). Then, the ECU 30 controls fuel injection by the injector 18 and supplies fuel of the fuel injection amount tau from the intake pipe 2 to the combustion chamber 13.
[0082]
Subsequently, the ECU 30 determines whether or not the coolant temperature thw detected by the coolant temperature sensor 21 is higher than a preset threshold value K_6, that is, the coolant temperature thw to the extent that the throttle valve 4 is fixed. It is determined whether or not the value becomes high. Further, the ECU 30 obtains a vehicle speed threshold value corresponding to the intake air temperature tha detected by the intake air temperature sensor 32 based on a preset function F_kaze (tha), and corresponds to the engine speed ne and the current shift position. It is determined whether or not the vehicle speed spd calculated from the reduction ratio is lower than a vehicle speed threshold value, that is, whether or not the vehicle speed spd is so low that the throttle valve 4 is not fixed due to icing (step 132).
[0083]
If the coolant temperature thw is so high that the throttle valve 4 is fixed, and the vehicle speed spd is not so low that the throttle valve 4 is not fixed due to icing (step 132, Yes), the ECU 30 is normal. After incrementing the count value csei by one (step 133), it is determined whether or not the normal count value csei has exceeded 100 (step 134).
[0084]
If the normal count value csei is stepped up to 100 while repeating the processing from step 101 (step 134, Yes), the coolant temperature thw is high enough that the sticking of the throttle valve 4 is eliminated, and Since the vehicle speed spd is not high enough to cause the throttle valve 4 to be fixed due to icing, the ECU 30 indicates that the intake pipe 2 is in a warm-up state and the throttle valve 4 has been fixed. Accordingly, the sticking determination flag xkochak is set to OFF, the sticking opening degree tako is set to 100 (step 135), and the process proceeds to step 136. A fixed opening degree tako 100 indicates a throttle valve opening which is not possible in practice.
[0085]
After the throttle valve 4 is fixed and the sticking determination flag xkochak is set to OFF, the temporary target opening t_tangle obtained in step 124 is the sum (tako + K_2) in step 127 or the difference (tako−) in step 129. It is no longer limited to K_1).
[0086]
If the coolant temperature thw is not so high that the throttle valve 4 is fixed, or if the vehicle speed spd is high enough that the throttle valve 4 is fixed due to freezing (No in step 132), or a normal count value. If csei is less than 100 (step 134, No), the process proceeds to step 136 without performing the process of step 135.
[0087]
In step 136, the ECU 30 sets the target shift position t_sft of the automatic transmission 29 to the temporary target shift position t_sft obtained in step 124, controls the automatic transmission 29, and sets the actual shift position to the target shift position t_sft. Set to. In addition, the ECU 30 sets the target opening degree tag of the throttle valve 4 to the temporary target opening degree t_tangle obtained in step 124 (step 137), and controls the throttle actuator 5 to control the opening degree of the throttle valve 4. The target opening degree is adjusted.
[0088]
That is, in the processing of steps 131 to 135, the coolant temperature thw is so high that the throttle valve 4 is fixed, and the vehicle speed spd is not so high that the throttle valve 4 is fixed due to freezing. Is sufficiently long, the sticking determination flag xkochak is set to OFF, and the temporary target opening t_tangle obtained in step 124 is limited to the sum (tako + K_2) in step 127 or the difference (tako-K_1) in step 129. To cancel.
[0089]
Thus, in this embodiment, based on the drive current duty of the throttle actuator 5, the change in the actual opening ta of the throttle valve 4, and the difference between the current temporary target opening t_tangle and the actual opening ta of the throttle valve 4, It is determined whether or not the throttle valve 4 is fixed. If the throttle valve 4 is fixed, the engine 1 is periodically vibrated greatly by periodically cutting the fuel injection or changing the shift position. The sticking of the valve 4 is eliminated.
[0090]
In addition, when the fixed opening degree tako of the throttle valve 4 is so small that the engine 1 is stopped or the fixed opening degree tako of the throttle valve 4 is so large that the engine 1 is overrun, the coolant water temperature thw is high, and Since the temporary target opening t_tangle of the throttle valve 4 is limited so as not to be set in the vicinity of the fixing opening tako until the vehicle speed spd is so low that the throttle valve 4 is not fixed, the throttle valve 4 is not set near the fixing opening tako. 4 is prevented from repeatedly sticking at the same position.
[0091]
Further, when the output torque of the engine 1 fluctuates, the shift position of the automatic transmission 29 is set to the fifth speed or neutral, or the lockup of the fluid coupling is released, so that the fluctuation of the output torque of the engine 1 is changed to the driving wheel of the automobile. The impact on the vehicle is alleviated so that the passengers of the car do not feel uncomfortable.
[0092]
In this embodiment, the engine is vibrated by cutting the fuel injection or changing the shift position. However, the present invention is not limited to this, and the present invention is not limited to this. The engine may be vibrated by changing the output torque of the engine by changing the opening / closing timing of the exhaust valve or changing the EGR amount.
[0093]
【The invention's effect】
As described above, according to the present invention, when the throttle valve is firmly fixed, the vibration of the intake passage is increased. This vibration eliminates icing of the throttle valve, the sticking of the throttle valve is eliminated, and throttle valve opening / closing control becomes possible.
[0095]
According to one embodiment, the output torque of the internal combustion engine is varied by increasing the period from the initial explosion to the complete explosion in the internal combustion engine, and the intake passage vibration is increased.
[0096]
According to one embodiment, an internal combustion engineFluctuating output torqueBy lettingSuckIt increases the vibration of the air passage.
[0097]
According to one embodiment, when the vibration of the intake passage is increased, the shift position of the transmission connected to the output shaft of the internal combustion engine is changed to the neutral position. When the shift position of the transmission is changed to the neutral position, the rotational fluctuation range of the internal combustion engine becomes large, and the fluctuation of the output torque of the internal combustion engine is hardly transmitted to the outside.
[0098]
According to one embodiment, the vibration of the intake passage is increased by changing the shift position of the transmission connected to the output shaft of the internal combustion engine.
[0099]
According to one embodiment, the vibration of the intake passage is increased by changing the shift position of the transmission connected to the output shaft of the internal combustion engine to the high geared side.
[0100]
According to one embodiment, the vibration of the intake passage is increased by changing the shift position of the transmission connected to the output shaft of the internal combustion engine to the low geared side.
According to one embodiment, once the sticking occurs, the throttle valve opening is close to the opening of the throttle valve when the sticking occurs until the intake pipe is warmed and cannot stick. This prevents the throttle valve from sticking repeatedly.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram showing an embodiment of a throttle sticking prevention device of the present invention.
FIG. 2 is a flowchart showing processing in the throttle sticking prevention device of FIG. 1;
3 is a flowchart showing processing subsequent to FIG. 2 in the throttle sticking prevention device of FIG. 1;
4 is a graph used to explain the operation of the throttle sticking prevention device of FIG. 1 when the throttle valve is stuck on the closed side. FIG.
FIG. 5 is a graph used to explain the operation of the throttle sticking prevention device of FIG. 1 when the throttle valve is stuck on the open side.
[Explanation of symbols]
1 Internal combustion engine
2 Intake pipe
3 Exhaust pipe
4 Throttle valve
5 Throttle actuator
6 Throttle sensor
8 cylinders
9 Piston
10 Connecting rod
11 Crankshaft
12 Cylinder head
13 Combustion chamber
14 Intake valve
15 Exhaust valve
17 Intake port
18 Injector
19 Spark plug
21 Water temperature sensor
22 Reference position sensor
23 Rotational speed sensor
24 Air flow meter
25 Accelerator pedal
26 Accelerator sensor
28 Shift sensor
29 Automatic transmission
30 ECU
31 Ignition key
32 Intake air temperature sensor
33 Valve timing variable mechanism

Claims (7)

A throttle sticking prevention device for an internal combustion engine for preventing sticking of a throttle valve provided in an intake passage that guides air to a combustion chamber of the internal combustion engine,
A sticking degree judging means for judging whether or not the sticking degree of the throttle valve is large;
A vibration control means for increasing the vibration of the intake passage when the sticking degree judging means determines that the sticking degree is large ;
When the internal combustion engine is started, if the sticking degree determination means determines that the sticking degree is large, the vibration control means prolongs the period from the initial explosion to the complete explosion in the internal combustion engine. An apparatus for preventing throttle sticking of an internal combustion engine that increases vibration of the intake passage by doing so . A throttle sticking prevention device for an internal combustion engine for preventing sticking of a throttle valve provided in an intake passage that guides air to a combustion chamber of the internal combustion engine,
A sticking degree judging means for judging whether or not the sticking degree of the throttle valve is large;
A vibration control means for increasing the vibration of the intake passage when the sticking degree judging means determines that the sticking degree is large;
After the internal combustion engine is started, if the sticking degree determination means determines that the sticking degree is large, the vibration control means increases the vibration of the intake passage by changing the output torque of the internal combustion engine. Throttle sticking prevention device. The internal combustion engine according to claim 2 , further comprising shift position changing means for changing a shift position of a transmission connected to an output shaft of the internal combustion engine to a neutral position when the vibration control means increases the vibration of the intake passage. Throttle sticking prevention device. A throttle sticking prevention device for an internal combustion engine for preventing sticking of a throttle valve provided in an intake passage that guides air to a combustion chamber of the internal combustion engine,
A sticking degree judging means for judging whether or not the sticking degree of the throttle valve is large;
A vibration control means for increasing the vibration of the intake passage when the sticking degree judging means determines that the sticking degree is large;
After the start of the internal combustion engine, when the sticking degree determining means determines that the sticking degree is large, the vibration control means changes the shift position of a transmission connected to the output shaft of the internal combustion engine, thereby throttle sticking prevention device of combustion engine Ru increases the vibration of the intake passage. 5. The internal combustion engine throttle sticking prevention device according to claim 4, wherein the vibration control means increases vibration of the intake passage by changing a shift position of a transmission connected to an output shaft of the internal combustion engine to a high geared side. . 5. The internal combustion engine throttle sticking prevention device according to claim 4 , wherein the vibration control means increases the vibration of the intake passage by changing a shift position of a transmission connected to the output shaft of the internal combustion engine to a low gear side. . Warm-up determination means for determining whether the intake passage is warmed up;
Until the intake passage is determined to be warmed up by the warm-up determination means, the opening degree of the throttle valve is close to the opening degree of the throttle valve when the sticking degree determination means determines that the fixing degree is large. The throttle sticking prevention device for an internal combustion engine according to any one of claims 1 to 6, further comprising prohibiting means for prohibiting entry .

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