JP2012117461A - Black smoke generation suppressing device, and black smoke generation suppressing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress the generation of black smoke and starting defect by limiting fuel injection amount on the basis of atmospheric pressure.SOLUTION: A black smoke generation suppressing device 30 of an engine 1 equipped with a mechanical governor 20 having a governor lever 24 for controlling the position of a control rack 27 according to the number of rotations and a tension lever 25 applying energizing force to the governor lever 24 corresponding to an acceleration operation, has: an atmospheric pressure sensor; a high altitude solenoid 32 for setting a movable range of the control rack 27 to a normal range or a quantity reduction range set to fuel quantity reduction side of the fuel by being brought into directly or indirectly contact with the tension lever 25; a key switch; and a controller operating the high altitude solenoid 32 so as to suppress the reduction in an excess air ratio according to the detected atmospheric pressure. The controller controls the high altitude solenoid 32 to operate after it is detected that the key switch is switched from an ON-position to a start position.

Description

  The present invention relates to a black smoke generation suppression device and a black smoke generation suppression method for an engine having a mechanical governor, which includes a governor lever that controls a control rack position according to the number of rotations, and a tension lever that is coupled to the governor lever via an elastic member.

  In a non-supercharged diesel engine using a mechanical fuel injection pump, fuel injection amount control according to the engine speed and load is performed by a governor mechanism configured using a spring or a link mechanism.

  When the engine is used at a high altitude where the atmospheric pressure is low, the fuel injection amount is kept constant in spite of the decrease in the air density, so the excess air ratio decreases. As a result, black smoke in the exhaust gas increases. The technology disclosed in Patent Documents 1, 2, and 3 aims to prevent the generation of black smoke due to such a pressure drop. These techniques reduce the fuel injection amount when the atmospheric pressure drops in an engine equipped with a mechanical governor.

  In Patent Document 1, the rotation range of the operation member 32 interlocked with the tension lever 30 is limited by the position changing member. The position of the position variation member 50 varies according to the atmospheric pressure detected by the barometer. The barometer is constituted by a bellows 48 kept in a vacuum.

  In Patent Document 2, the rotation range of the spring input lever 14 is limited by the fuel limiting pin 4. The position of the fuel limiting pin 4 varies depending on the atmospheric pressure detected by the barometer. The barometer is constituted by a bellows 31 kept in a vacuum.

  In Patent Document 3, the driving of the mechanical governor 2 is limited according to the operation amount of the manual selection device 20. The manual selection device 20 has a plurality of switching positions set according to an altitude such as 2000 m.

Japanese Patent Laid-Open No. 8-232687 Japanese Patent Laid-Open No. 9-42014 JP 2004-132197 A

  When the fuel injection amount is limited based on the atmospheric pressure when starting the engine, there is a possibility that the engine cannot be started due to insufficient output. Therefore, the present invention provides a black smoke generation suppression device and black smoke that can prevent the occurrence of a start failure while preventing the generation of black smoke due to the reduction of the excess air ratio by limiting the fuel injection amount based on the atmospheric pressure. An occurrence suppression method is provided.

  The present invention provides a black smoke generation suppression device for an engine having a mechanical governor, comprising a governor lever that controls a control rack position according to the number of rotations, and a tension lever that applies a biasing force according to an accelerator operation amount to the governor lever. An atmospheric pressure sensor that detects atmospheric pressure and a solenoid that sets the movable range of the control rack to the normal range or a reduction range that is set on the fuel reduction side of the normal range by directly or indirectly contacting the tension lever. And a starter operating device for inputting a starter start command for starting the starter and a starter stop command for stopping the starter, a solenoid to operate the starter so as to suppress a decrease in the excess air ratio according to the detected atmospheric pressure, And a control device that can detect the input of a start command and a starter stop command. And, the control device, after detecting the starter stop instruction to actuate the solenoid to provide a black smoke generation suppressing device for an engine, characterized in that.

(A) Preferably, a certain waiting time is provided between the time when the starter stop command is detected and the time when the control device commands the operation of the solenoid.

(B) Preferably, a variable waiting time is provided between the time when the starter stop command is detected and the time when the control device commands the operation of the solenoid, and the variable waiting time is determined when the starter start command is detected. It increases in accordance with the increase in the starter operation time from the time point to the time point when the starter stop command is detected.

(C) Preferably, the control device repeatedly or irregularly repeats the operation of the solenoid during operation of the engine.

(D) Preferably, an air temperature sensor for detecting the air temperature is further provided, and the control device suppresses a decrease in the excess air rate according to not only the detected atmospheric pressure but also the detected air temperature. Activating the solenoid.

  The present invention can prevent the occurrence of starting failure while preventing the generation of black smoke due to the reduction of the excess air ratio by limiting the fuel injection amount based on the atmospheric pressure.

It is a figure which shows the structure of an engine. It is a figure which shows the structure of a mechanical governor and a black smoke generation | occurrence | production suppression apparatus. It is a flowchart of black smoke generation | occurrence | production suppression control. It is a figure which shows the high altitude solenoid and stop solenoid at the time of an engine stop. It is a figure which shows the high ground solenoid and stop solenoid in control at the time of starting, and low ground control. It is a figure which shows the high altitude solenoid and stop solenoid in high altitude control. It is a figure which shows an example of the time chart of a high altitude solenoid and a stop solenoid. It is a flowchart of black smoke generation | occurrence | production suppression control (2nd Embodiment). It is a figure which shows the structure of an engine (4th Embodiment). It is a flowchart of black smoke generation | occurrence | production suppression control (4th Embodiment).

(First embodiment)
FIG. 1 is a diagram showing a configuration of the engine 1. The engine 1 includes a cylinder 2, a piston 3, a crankshaft 4, an intake rod 5, an exhaust pipe 6, an injector 8, an accelerator lever 9, and a mechanical governor 20. By operating the accelerator lever 9, the fuel injection amount from the injector 8 is changed via the mechanical governor 20. Here, the mechanical governor 20 adjusts the fuel injection amount from the injector 8 in accordance with not only the operation amount of the accelerator lever 9 but also the rotational speed of the crankshaft 4.

  The engine 1 also includes a control device 10 as a start control device, a key switch 11, and a starter motor 12. The control device 10 controls the operation of the starter motor 12 based on the operation of the key switch 11.

  The engine 1 also includes an atmospheric pressure sensor 13. The atmospheric pressure sensor 13 detects atmospheric pressure. The atmospheric pressure sensor 13 constitutes a part of a black smoke generation suppression device 30 described later.

  The engine 1 includes a control panel 15. The key switch 11 and the atmospheric pressure sensor 13 are disposed on the control panel 15.

  FIG. 2 is a diagram illustrating the configuration of the mechanical governor 20 and the black smoke generation suppression device 30. In FIG. 2, the mechanical governor 20 includes a governor shaft 21, a flyweight 22, a governor sleeve 23, a governor lever 24, a tension lever 25, a spring 26, a control rack 27, and a fuel plunger 28. The governor shaft 21 is connected to the crankshaft 4. The governor lever 24 and the tension lever 25 are rotatably provided around the support shaft 29. The support shaft 29 is supported by the casing of the mechanical governor 20. One end of the governor lever 24 and one end of the tension lever 25 are connected via a spring 26. The other end of the governor lever 24 is connected to the control rack 27 through a link. The other end of the tension lever 25 is connected to the accelerator lever 9 via a link. The fuel plunger 28 is connected to the injector 8 through a fuel pipe.

  The governor shaft 21 is linked to the crankshaft 4. The flyweight 22 spreads due to the centrifugal force generated by the rotation of the governor shaft 21. As a result, the flyweight 22 pushes out the governor sleeve 23, so that the governor sleeve 23 projects outward in the axial direction of the governor shaft 21. When the governor lever 24 is tilted by the protrusion of the governor sleeve 23, the position of the control rack 27 is changed. By changing the position of the control rack 27, the opening area of the passage for supplying fuel into the fuel plunger 28 is changed. As a result, the fuel injection amount is changed. On the other hand, the accelerator lever 8 is a member operated by the user, and the tension lever 25 tilts according to the amount of accelerator operation by the accelerator lever 8. Since the governor lever 24 is connected to the tension lever 25 via the spring 26, the governor lever 24 also tilts in conjunction with the tension lever 25. As a result, the governor lever 24 adjusts the fuel injection amount in accordance with the engine speed and the accelerator operation amount.

  The black smoke generation suppression device 30 will be described with reference to FIGS. 1 and 2. The black smoke generation suppression device 30 executes or cancels the restriction on the fuel injection amount so as to suppress the decrease in the excess air ratio.

  1 and 2, the black smoke generation suppression device 30 includes a control device 10, a key switch 11, an atmospheric pressure sensor 13, a stopper 31, a highland solenoid 32, and a highland output adjustment bolt 33. The control device 10, the key switch 11, and the atmospheric pressure sensor 13 are shown in FIG. The stopper 31, the highland solenoid 32, and the highland output adjustment bolt 33 are shown in FIG.

  The stopper 31 is supported rotatably with respect to the casing of the mechanical governor 20. The highland solenoid 32 and the highland output adjustment bolt 33 are arranged so as to limit the rotation range of the stopper 31. The core shaft 32 a of the high altitude solenoid 32 is disposed so as to be able to contact the stopper 31. The highland output adjustment bolt 33 is disposed so as to be able to contact the stopper 31. The stopper 31 is disposed so as to be able to contact the tension lever 25. For this reason, the high altitude solenoid 32 and the high altitude output adjustment bolt 33 can limit the movable range of the stopper 31. Therefore, the high altitude solenoid 32 and the high altitude output adjustment bolt 33 limit the movable range of the control rack 27 via the tension lever 25 and the governor lever 24.

  The control device 10 controls the driving of the high altitude solenoid 32 based on the atmospheric pressure detected by the atmospheric pressure sensor 13. The control device 10 controls the position of the core shaft 32 a by controlling energization of the Hold coil and Pull coil in the high altitude solenoid 32. Possible positions of the core shaft 32a are a push position and a pull position. The push position is set closer to the tension lever 25 than the pull position.

  The control device 10 controls the driving of the high altitude solenoid 32 based on the switching operation of the key switch 11 and the elapsed time from the switching operation time point. The switching operation of the key switch 11 and the elapsed time from the switching operation time correspond to the engine driving state to some extent. The user can operate the key switch 11 by inserting a key into the key switch 11 and operating the key. Possible positions of the key switch 11 are an OFF position, an ON position (ignition ON position), and a start position (engine start position).

  The key switch 11 is a starter operating device for inputting a starter start command for starting the starter motor 11 and a starter stop command for stopping the starter. The switching operation of the key switch 11 from the OFF position to the ON position is an input to the control device 10 for a starter start command. The switching operation from the ON position of the key switch 11 to the start position is an input to the control device 10 of a starter stop command. The control device 10 can detect an input of a starter start command and an input of a starter stop command. Moreover, the control apparatus 10 can detect the time (starter operation time) from the detection time of the starter start command to the detection time of the starter stop command.

  In FIG. 2, the mechanical governor 20 includes a restriction mechanism for the tension lever 25 when the engine is stopped. The limiting mechanism of the tension lever 25 includes a control device 10, a key switch 11, and a stop solenoid 40. The stop solenoid 40 is disposed so as to limit the rotation range of the tension lever 25. The core shaft 40 a of the stop solenoid 40 is disposed so as to be able to contact the tension lever 25. For this reason, the stop solenoid 40 can limit the movable range of the tension lever 25. As a result, the movable range of the control rack 27 is limited, but the fuel injection amount can be changed from the minimum to the maximum within the limited movable range. That is, the stop solenoid 40 does not limit the fuel injection amount.

  The control device 10 controls the driving of the stop solenoid 40 based on the switching operation of the key switch 11 and the elapsed time from the switching operation time point.

  The black smoke generation suppression control will be described with reference to FIGS. The black smoke generation suppression control refers to the control of the high altitude solenoid 32 by the control device 10. FIG. 3 is a flowchart of black smoke generation suppression control. First, the black smoke generation suppression control will be basically described according to the flow shown in FIG.

  FIG. 4 is a diagram showing the high altitude solenoid 32 and the stop solenoid 40 when the engine is stopped. As shown in FIG. 4, when the engine is stopped, the core shaft 32a of the high altitude solenoid 32 is in the push position PH32, and the core shaft 40a of the stop solenoid 40 is in the pull position PL40. At this time, the tension lever 25 is inclined to the fuel reduction side FD, and the control rack 27 is also on the fuel reduction side FD.

  In step S <b> 1 of FIG. 2, when the control device 10 recognizes that the key switch 11 has been switched from the OFF position to the ON position, the control device 10 operates the starter motor 12. As a result, the engine 1 is started.

  Following step S1, step S2 is executed. In step S2, the control device 10 starts the start-time control. In the startup control, the movable range of the control rack 27 is set to the normal range. In the normal range, the changeable range of the fuel injection amount is basically not limited.

  FIG. 5 is a diagram showing the high altitude solenoid 32 and the stop solenoid 40 in the start time control and the low altitude control. With the start-up control, the control device 10 moves the core shaft 32a of the high altitude solenoid 32 from the push position PH32 to the pull position PL32, and moves the core shaft 40a of the stop solenoid 40 from the pull position PL40 to the push position PH40. Let During execution of the start-time control, the control device 10 keeps the core shaft 32a of the high altitude solenoid 32 at the pull position PL32 and keeps the core shaft 40a of the stop solenoid 40 at the push position PH40. In the start-up control, the movable range of the control rack 27 is within the normal range limited only by the stop solenoid 40, so the range in which the fuel injection amount can be changed is not limited.

  Following step S2, step S3 is executed. In step S3, when the control device 10 recognizes that the key switch 11 has been switched from the ON position to the start position, the control device 10 stops the operation of the starter motor 12.

  Following step S3, step S4 is executed. In step S4, when the control device 10 detects that a certain waiting time w has elapsed from the time of switching to the start position, the control device 10 executes the determination process of step S5. The waiting time w is set to 5 seconds, for example.

  In step S5, the control device 10 determines whether or not the atmospheric pressure P is smaller than a predetermined threshold value α. When the atmospheric pressure P is smaller than the threshold value α, the control device 10 executes Step S6. When the atmospheric pressure P is greater than or equal to the threshold value α, the control device 10 executes Step S7.

  The threshold value α is set to 90 kPa, for example. One atmosphere is about 101.3 kPa. That is, the threshold value α is set to about 0.9 atmospheric pressure.

  In step S6, the control device 10 starts high altitude control. In the high altitude control, the movable range of the control rack 27 is set to the weight reduction range. The reduction range is set on the fuel reduction side of the normal range.

  FIG. 6 is a diagram showing the high altitude solenoid 32 and the stop solenoid 40 in the high altitude control. With the start of the high altitude control, the control device 10 moves the core shaft 32a of the high ground solenoid 32 from the pull position PL32 to the push position PH32, and moves the core shaft 40a of the stop solenoid 40 from the push position PH40 to the pull position PL40. . During execution of the start-time control, the control device 10 keeps the core shaft 32a of the high altitude solenoid 32 at the push position PH32 and keeps the core shaft 40a of the stop solenoid 40 at the pull position PL40. In the start-up control, the movable range of the control rack 27 is in the reduction range limited by the high altitude solenoid 32, so the range in which the fuel injection amount can be changed is limited to the reduction side.

  In step S7, the control device 10 starts the lowland control. In the lowland control, the movable range of the control rack 27 is set to the normal range. The lowland control is the same control as the start time control. When the process proceeds from step S5 to step S7, the control device 10 in the lowland control is the same as during execution of the start time control in the highland solenoid 32 and the stop solenoid 40. Keep in state.

  As shown in FIG. 5, during execution of the lowland control, the control device 10 keeps the core shaft 32a of the highland solenoid 32 at the pull position PL32 and keeps the core shaft 40a of the stop solenoid 40 at the push position PH40.

  With reference to FIG. 7, an example of black smoke generation suppression control is shown. FIG. 7 is a diagram illustrating an example of a time chart of the high altitude solenoid 32 and the stop solenoid 40. FIG. 7 shows the energized state of the Hold coil, the energized state of the Pull coil, and the position of the core shaft for each of the high altitude solenoid 32 and the stop solenoid 40. The control device 10 controls the energization state of the Hold coil and the energization state of the Pull coil for the high altitude solenoid 32 and the stop solenoid 40. As a result, the positions of the core shafts of the high altitude solenoid 32 and the stop solenoid 40 are controlled.

  Time t0 indicates the time when the key switch 11 is switched from the OFF position to the ON position. Prior to time t0, the engine 1 is stopped. As shown in FIG. 4, when the engine 1 is stopped, the core shaft 32a of the high altitude solenoid 32 is maintained at the push position PH32, and the core shaft 40a of the stop solenoid 40 is maintained at the pull position PL40.

  Time t1 indicates the time when the key switch 11 is switched from the ON position to the start position. From time t0 to time t1, the engine 1 is started. As shown in FIG. 5, when the engine 1 is started, the core shaft 32a of the high altitude solenoid 32 is maintained at the pull position PL32, and the core shaft 40a of the stop solenoid 40 is maintained at the push position PH40.

  Time t2 indicates the time when the standby time w has elapsed from time t1. Time t3 indicates the time when the high altitude control is started. Between the time t2 and the time t3, the control apparatus 10 performs the process of step S5. That is, the control device 10 calculates the atmospheric pressure P based on the detected atmospheric pressure P0, and compares the atmospheric pressure P with the threshold value α.

  After time t3, the high altitude control is being executed. As shown in FIG. 6, during execution of high altitude control, the core shaft 32a of the high altitude solenoid 32 is maintained at the push position PH32, and the core shaft 40a of the stop solenoid 40 is maintained at the pull position PL40.

  The first embodiment has the following actions and effects. In the first embodiment, the movable range of the control rack 27 is set to the normal range or the fuel decrease side of the normal range so as to suppress the decrease of the excess air ratio according to the detected atmospheric pressure. Set to range. In the first embodiment, the control of the movable range of the control rack 27 is performed after the standby time w has elapsed from the start of startup. That is, the fuel injection amount is not limited until the start of the engine 1 is completed. For this reason, 1st Embodiment can prevent generation | occurrence | production of a starting failure, preventing generation | occurrence | production of black smoke by the reduction | decrease in an excess air ratio by restrict | limiting fuel injection quantity based on atmospheric pressure.

(Second Embodiment)
The second embodiment is different from the first embodiment in the contents of the control flow. The configuration of the engine 1 is common to the first embodiment and the second embodiment. Therefore, the control flow in the second embodiment will be described below.

  FIG. 8 is a flowchart of black smoke generation suppression control. The control flow of the second embodiment further includes step S8 in addition to the configuration of the control flow of the first embodiment.

  As described above, highland control is started in step S6, and lowland control is started in step S7. Step S8 is performed after the start of step S6 or step S7. In step S8, when the control device 10 detects that a certain time has elapsed from the start time of the highland control or the lowland control, the control device 10 executes step S5 again. As a result, the determination process in step S5 is executed at regular time intervals, and highland control or lowland control is newly started.

  The second embodiment has the following operations and effects. In the second embodiment, the high altitude solenoid 32 is operated according to the detected atmospheric pressure at regular time intervals. That is, when the air density is low, the output is suppressed to prevent the excess air ratio from decreasing, and when the air density is high, the output restriction is released. For this reason, 2nd Embodiment can fully demonstrate an output, suppressing generation | occurrence | production of black smoke according to the change of atmospheric pressure.

  In addition, step S5 may be re-executed not only regularly but also irregularly.

(Third embodiment)
The third embodiment is different from the first and second embodiments in the configuration of the standby time w. Below, the waiting time w in 3rd Embodiment is demonstrated.

  In the third embodiment, a variable waiting time w is adopted instead of the constant waiting time w. The variable waiting time w is determined based on the length of the energization time of the starter motor 12. The energization time ts of the starter motor 12 generally corresponds to the time from the time when the key switch 11 is switched from the OFF position to the ON position until the time when the key switch 11 is switched from the ON position to the start position.

(1) When ts ≦ 5 (seconds), the standby time w is set to 5 (seconds).
(2) When 5 <ts ≦ 10 (seconds), the standby time w is set to 10 (seconds).
(3) When 10 (seconds) <ts, the standby time w is set to 15 (seconds).

  The third embodiment has the following operations and effects. In the third embodiment, as the time required for starting the engine 1 becomes longer, the start time of control of the movable range of the control rack is delayed. For this reason, the first embodiment can further prevent the occurrence of a starting failure.

(Fourth embodiment)
In the fourth embodiment, in order to suppress a decrease in the excess air ratio, the driving of the high altitude solenoid 32 is controlled based not only on the atmospheric pressure but also on the air temperature. On the other hand, in the first to third embodiments, the drive of the high altitude solenoid 32 is controlled based only on the atmospheric pressure. Below, the difference between 1st Embodiment and 4th Embodiment is demonstrated.

  FIG. 9 is a diagram showing a configuration of the engine 1. The engine 1 further includes an air temperature sensor 14. The temperature sensor 14 is disposed on the control panel 15. The temperature sensor 14 detects the temperature. The air temperature sensor 14 constitutes a part of the black smoke generation suppression device 30 in the fourth embodiment.

  9 and 2, the black smoke generation suppression device 30 includes a control device 10, a key switch 11, an atmospheric pressure sensor 13, an air temperature sensor 14, a stopper 31, a high altitude solenoid 32, and a high altitude output adjustment bolt 33. The control device 10, the key switch 11, the atmospheric pressure sensor 13, and the temperature sensor 14 are shown in FIG. The stopper 31, the highland solenoid 32, and the highland output adjustment bolt 33 are shown in FIG.

  FIG. 10 is a flowchart of black smoke generation suppression control. The flowchart (FIG. 10) in the fourth embodiment differs from the flowchart (FIG. 3) in the first embodiment in the configuration of step S5.

  In step S5, the control device 10 determines whether or not the atmospheric pressure P after the temperature correction is smaller than a predetermined threshold value α. When the atmospheric pressure P after the temperature correction is smaller than the threshold value α, the control device 10 executes Step S6. When the atmospheric pressure P after the temperature correction is equal to or higher than the threshold value α, the control device 10 executes Step S7.

The atmospheric pressure P after the temperature correction is given by, for example, equation (1).
P = T / (273 + 25) × P0 (1)
Here, T is temperature (K), and P0 is atmospheric pressure (kPa). The denominator (273 + 25) of the first term indicates a temperature difference between 0 degrees Celsius and absolute zero plus a predetermined reference temperature. Here, the reference temperature is set to 25 degrees. As described above, the atmospheric pressure P 0 is detected by the atmospheric pressure sensor 13, and the temperature T is detected by the temperature sensor 14. The control device 10 can calculate the atmospheric pressure P after the temperature correction based on the detected atmospheric pressure P0 and the temperature T.

  In step S5, the control device 10 calculates the atmospheric pressure P after the temperature correction based on the detected atmospheric pressure P0 and the temperature T, and compares the atmospheric pressure P after the temperature correction with the threshold value α.

  The fourth embodiment has the following actions and effects. In the fourth embodiment, the movable range of the control rack 27 is set on the fuel reduction side of the normal range or the normal range so as to suppress the decrease in the excess air ratio according to the detected atmospheric pressure and temperature. The weight loss range is set. For this reason, in the fourth embodiment, the generation of black smoke due to the increase in the excess air ratio is more accurately controlled by limiting the fuel injection amount based on not only the decrease in atmospheric pressure but also the decrease in air density due to the increase in temperature. Can be prevented.

DESCRIPTION OF SYMBOLS 1 Engine 10 Control apparatus 12 Starter motor 13 Atmospheric pressure sensor 14 Temperature sensor 20 Mechanical governor 24 Governor lever 25 Tension lever 27 Control rack 30 Black smoke generation suppression device 32 High altitude solenoid P Atmospheric pressure P0 detected atmospheric pressure T Detected temperature

Claims (5)

In an apparatus for suppressing black smoke generation of an engine having a mechanical governor, comprising: a governor lever that controls a control rack position according to the number of revolutions; and a tension lever that applies an urging force according to an accelerator operation amount to the governor lever.
An atmospheric pressure sensor for detecting atmospheric pressure;
A solenoid that sets the movable range of the control rack to a normal range or a reduction range that is set on the fuel reduction side of the normal range by directly or indirectly contacting the tension lever;
A starter operating device for inputting a starter start command for starting the starter and a starter stop command for stopping the starter;
A solenoid that operates to suppress a decrease in the excess air ratio according to the detected atmospheric pressure, and a control device that can detect the input of a starter start command and a starter stop command.
An engine black smoke generation suppressing device, wherein the control device operates a solenoid after detecting a starter stop command.   2. The engine black smoke generation suppressing device according to claim 1, wherein a certain waiting time is provided between the time when the starter stop command is detected and the time when the control device commands the operation of the solenoid. A variable waiting time is provided between the time when the starter stop command is detected and the time when the control device commands the operation of the solenoid.
2. The engine black smoke generation suppressing device according to claim 1, wherein the variable waiting time increases in accordance with an increase in a starter operation time from a detection time of a starter start command to a detection time of a starter stop command.   4. The engine black smoke generation suppression device according to claim 1, wherein the control device is operated periodically or irregularly during operation of the engine to operate the solenoid. 5. In addition, it has a temperature sensor that detects the temperature,
5. The control device according to claim 1, wherein the control device operates the solenoid so as to suppress a decrease in the excess air ratio in accordance with not only the detected atmospheric pressure but also the detected air temperature. Engine black smoke generation suppression device.

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