JP2006249974A - Evaporated fuel processing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the smoothness of an internal combustion engine when starting in an evaporated fuel processing device for feeding an evaporated fuel to each of cylinders at engine start. <P>SOLUTION: A canister for accumulating the evaporated fuel is allowed to communicate with the intake port of each of the cylinders. A purge control valve for each of the cylinders is opened in synchronism with a crank angle after the starting of the internal combustion engine (open arrow in Fig. (D)). The position of a crank advanced by a purge advance angle amount from a crank angle at which an intake stroke is started in each of the cylinders is set to a purge start angle corresponding to each of the intake strokes. Purge advance angle amounts corresponding to an intake stroke at initial explosion performed together with an initial explosion (#3 cylinder) and an intake stroke immediately after initial explosion performed after that step are set larger than a purge advance angle amount corresponding to an intake stroke before initial explosion (#2 and #1 cylinders). <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an evaporated fuel processing apparatus, and more particularly to an evaporated fuel processing apparatus for supplying evaporated fuel to individual cylinders when an internal combustion engine is started.

  Conventionally, for example, as disclosed in Japanese Utility Model Laid-Open No. 6-37548, a canister that adsorbs evaporated fuel generated inside a fuel tank is provided, and the evaporated fuel adsorbed inside the fuel tank is removed during operation of the internal combustion engine. Devices for inhaling an internal combustion engine are known.

  More specifically, this apparatus includes a purge passage that connects the canister and the intake passage of the internal combustion engine, and a control valve that controls the conduction state of the purge passage. The control valve is duty-driven, thereby changing the flow resistance of the purge passage and controlling the flow rate of the evaporated fuel flowing from the canister toward the intake passage.

  According to the above conventional apparatus, the evaporated fuel adsorbed by the canister can be caused to flow into the cylinder of the internal combustion engine by opening the control valve during the operation of the internal combustion engine. Since the evaporated fuel is already vaporized, it exhibits good combustibility even during cold start. For this reason, according to the above-described conventional apparatus, the startability of the internal combustion engine can be improved by causing the internal combustion engine to suck the evaporated fuel in the canister from the start of the internal combustion engine.

Japanese Utility Model Publication No. 6-37548 JP-A-8-200166

  When the internal combustion engine is started using the above-described conventional system, the control valve that opens and closes the purge passage is synchronized with the crank angle in order to inhale a desired amount of evaporated fuel into each cylinder accurately. It is possible to control with. More specifically, it is conceivable that the valve opening timing of the control valve is determined as, for example, “at the time of a predetermined crank angle before the intake stroke is started in each cylinder”.

  According to such a control method, after the start of the internal combustion engine is started, purge and intake can be continuously executed in each cylinder. In this case, each cylinder sucks the evaporated fuel purged with respect to the cylinder in each intake stroke. Therefore, according to such a control method, the control accuracy of the amount of evaporated fuel sucked into each cylinder can be increased, and the startability of the internal combustion engine can be improved.

  By the way, the amount of evaporated fuel sucked into each cylinder is substantially determined by the magnitude of the negative pressure generated in the intake passage and the valve opening time of the control valve. Immediately after the cranking is started, that is, before the engine speed rises, the intake pipe pressure becomes a value near atmospheric pressure. In this case, a relatively long purge time is required to purge a sufficient amount of evaporated fuel. On the other hand, since the angular speed of the crankshaft is slow before the engine speed rises, a sufficiently long time can be secured between the crank angle at which the control valve is opened and the crank angle at which the intake stroke ends. For this reason, immediately after the start of cranking, the crank angle synchronization control is performed, so that a desired amount of evaporated fuel can be sucked into each cylinder.

  After starting the internal combustion engine, after the engine speed has risen sufficiently, the angular speed of the crankshaft is fast. Therefore, after opening the control valve in synchronization with the crank angle, the time that can be secured until the intake stroke is completed is short. . However, since the intake pipe pressure is sufficiently negative after the engine speed has risen, a sufficient amount of evaporated fuel can be caused to flow into the cylinder with a short purge. For this reason, a desired amount of evaporated fuel can be supplied to each cylinder by controlling the crank angle synchronization even after the engine speed has risen sufficiently.

  However, in the process in which the engine speed rises after the initial explosion occurs in the internal combustion engine, a situation occurs in which the crankshaft rotates at a high speed while the intake pipe pressure is close to atmospheric pressure. In this case, if the control valve is controlled under the same conditions as before the rise of the engine speed, a sufficient purge time cannot be secured until the intake stroke is completed. A situation occurs in which the amount of inflow of fuel becomes insufficient. For this reason, if the purge is controlled by a simple crank angle synchronization method at the time of starting the internal combustion engine, the start-up after the initial explosion occurs, and good startability is not necessarily obtained.

  The present invention has been made to solve the above-described problems. At the time of starting the internal combustion engine, by continuously supplying an appropriate amount of evaporated fuel to the individual cylinders, evaporation that can realize a smooth start can be realized. It aims at providing a fuel processor.

In order to achieve the above object, a first invention is an evaporated fuel processing apparatus for supplying evaporated fuel to an internal combustion engine having a plurality of cylinders,
A canister that stores evaporative fuel;
A purge passage communicating the canister to the intake port of each cylinder;
A purge control valve provided for each cylinder to control the conduction state between the intake port of each cylinder and the canister;
Control valve drive means for opening the purge control valves of the individual cylinders for a predetermined purge time in synchronization with the crank angle after the internal combustion engine is started,
A purge start angle setting means for setting a position advanced by a purge advance amount from a crank angle at which an intake stroke is started in each cylinder as a purge start crank angle corresponding to each intake stroke;
The purge advance amount corresponding to the intake stroke immediately after the first explosion executed following the intake stroke at the time of the first explosion executed simultaneously with the first explosion is set to the intake stroke before the first explosion executed before the intake stroke at the time of the first explosion. An advance amount setting means for setting a larger value than the purge advance amount corresponding to
It is characterized by providing.

  According to a second aspect of the present invention, in the first aspect, the advance amount setting means is configured so that the purge advance amount corresponding to the intake stroke at the time of the initial explosion is also the purge advance amount corresponding to the intake stroke before the initial explosion. It is characterized by being set larger than the angular amount.

Further, in a third aspect based on the first aspect or the second aspect, the advance amount setting means includes:
Purge number counting means for counting the number of purges performed after the start of the internal combustion engine, with the control valve being opened once for the purge time in one cylinder;
Rule storage means for storing a rule defining a relationship between the number of purges and the purge advance amount;
Setting means for setting purging advance amount in each cylinder according to the rule based on the number of purges;
It is characterized by including.

According to a fourth invention, in any one of the first to third inventions,
A purge time correcting means for correcting the purge time based on the state of the internal combustion engine;
The advance amount setting means includes an advance amount correction means for correcting the purge advance amount so as to match the expansion and contraction of the purge time.

The fifth invention is the fourth invention, wherein
A cooling water temperature detecting means for detecting the cooling water temperature of the internal combustion engine;
The purge time correction means includes correction means for increasing the purge time as the cooling water temperature is lower,
The advance angle correction means includes a correction means for increasing the purge advance angle as the cooling water temperature is lower.

The sixth invention is the fourth or fifth invention, wherein
Correlation value acquisition means for acquiring an intake pipe pressure correlation value having a correlation with the intake pipe pressure at the time of cranking,
The purge time correction means includes correction means for increasing the purge time as the intake pipe pressure is closer to atmospheric pressure based on the intake pipe pressure correlation value,
The advance angle correction means includes correction means for increasing the purge advance angle as the intake pipe pressure is closer to atmospheric pressure based on the intake pipe pressure correlation value.

The seventh invention is the sixth invention, wherein
The intake pipe pressure correlation value includes the engine speed,
The purge time correction means corrects the purge time longer as the engine speed during cranking is lower,
The advance angle correction means corrects the purge advance amount to a greater extent as the engine speed during cranking is lower.

The eighth invention is the sixth or seventh invention, wherein
The intake pipe pressure correlation value includes an idle speed control opening,
The purge time correction means corrects the purge time longer as the idle speed control opening during cranking is larger,
The advance angle correction means corrects the purge advance angle as the idle speed control opening during cranking increases.

According to a ninth invention, in any of the sixth to eighth inventions,
The intake pipe pressure correlation value includes a battery voltage;
The purge time correction means corrects the purge time longer as the battery voltage during cranking is lower,
The advance angle correction means corrects the purge advance angle larger as the battery voltage during cranking is lower.

According to a tenth aspect, in any of the sixth to ninth aspects,
Cylinder discrimination means for generating a cylinder discrimination signal when the absolute position of the crank angle is determined after the internal combustion engine is started,
A cylinder discrimination time measuring means for measuring a cylinder discrimination time required until the cylinder discrimination signal is issued after the internal combustion engine is started,
The intake pipe pressure correlation value includes the cylinder discrimination time,
The purge time correction means corrects the purge time longer as the cylinder discrimination time is shorter,
The advance angle correction means corrects the purge advance angle larger as the cylinder discrimination time is shorter.

  According to the first invention, after the internal combustion engine is started, the purge control valves of the individual cylinders can be opened for a predetermined purge time in synchronization with the crank angle. Further, for the purge corresponding to the intake stroke immediately after the first explosion, the start crank angle of the purge time can be advanced as compared with the start crank angle of the purge corresponding to the intake stroke before the first explosion. If the start crank angle of the purge time is advanced, it becomes easy to ensure a long purge time before the end of the intake stroke. For this reason, according to the present invention, only the angular velocity of the crankshaft is suddenly increased even with respect to the purge performed in response to the intake stroke immediately after the first explosion, that is, while the intake pipe pressure is maintained at a value close to the atmospheric pressure. Sufficient purge time is also provided for purges performed under conditions that show a rapid rise. Therefore, according to the present invention, when the internal combustion engine is started, an appropriate amount of evaporated fuel can be continuously supplied to each cylinder, and smooth startability can be realized.

  According to the second aspect of the invention, it is possible to advance the start crank angle of the purge time for the purge corresponding to the intake stroke at the first explosion. Since the angular velocity of the crankshaft increases simultaneously with the occurrence of the first explosion, the intake stroke at the time of the first explosion is completed in a shorter time than the intake stroke before the first explosion. Therefore, it is difficult to secure a sufficient purge time for the purge corresponding to the intake stroke at the first explosion as compared to the purge corresponding to the intake stroke before the first explosion. According to the present invention, it is possible to create a situation in which a long purge time can be easily secured by advancing the start crank angle of the purge time. For this reason, according to this invention, compared with the case of 1st invention, a favorable condition can be created in order to start an internal combustion engine smoothly further.

  According to the third invention, the start crank angle of the purge time for each cylinder is set in relation to the number of purges. The starting crank angle for ensuring a desired purge time varies depending on the magnitude of the intake negative pressure and the angular velocity of the crankshaft. These combinations show a change according to the number of purges after starting. Therefore, if the start crank angle is set based on the number of purges, an appropriate start crank angle can always be set immediately after starting the internal combustion engine without depending on various sensor outputs.

  According to the fourth invention, the purge time can be corrected based on the state of the internal combustion engine, and the purge advance amount can be corrected in accordance with the expansion and contraction of the purge time. For this reason, according to the present invention, after the internal combustion engine is started, a purge time suitable for supplying a desired fuel amount and a purge advance amount necessary for ensuring the purge time are always set. be able to.

  According to the fifth aspect of the invention, it is possible to ensure good startability by increasing the purge time as the cooling water temperature is lower. Moreover, the start crank angle that can secure a desired purge time can be set by increasing the purge advance amount as the coolant temperature is lower.

  According to the sixth aspect of the invention, as the intake pipe negative pressure at the time of cranking is smaller, the purge time is lengthened, so that the fuel amount necessary for obtaining good startability can be ensured. Further, by increasing the purge advance amount as the intake pipe negative pressure at the time of cranking is smaller, it is possible to set a start crank angle that can ensure a desired purge time.

  According to the seventh aspect of the invention, the lower the engine speed during cranking, the longer the purge time and the larger the advance amount of purge. The engine speed has a correlation with the intake pipe pressure. Therefore, according to the present invention, it is possible to set an appropriate purge time for supplying a desired amount of fuel and an appropriate start crank angle for ensuring the purge time.

  According to the eighth invention, the purge time can be increased and the purge advance angle can be increased as the idle speed control opening during cranking is increased. The idle speed control opening has a correlation with the intake pipe pressure at the start. Therefore, according to the present invention, it is possible to set an appropriate purge time for supplying a desired amount of fuel and an appropriate start crank angle for ensuring the purge time.

  According to the ninth aspect, the purge time can be increased and the purge advance amount can be increased as the battery voltage during cranking is lower. When the battery voltage is low, the cranking speed is slow, and the intake pipe pressure is easily maintained near atmospheric pressure. Thus, the battery voltage has a correlation with the intake pipe pressure at the start. Therefore, according to the present invention, it is possible to set an appropriate purge time for supplying a desired amount of fuel and an appropriate start crank angle for ensuring the purge time.

  According to the tenth aspect of the invention, the shorter the time required until the cylinder discrimination signal is issued after the internal combustion engine is started, the longer the purge time and the larger the advance amount of purge. The intake pipe pressure at the end of cylinder discrimination tends to be close to atmospheric pressure as the time required for the discrimination is shorter. Thus, the time required for cylinder discrimination has a correlation with the intake pipe pressure during cranking. Therefore, according to the present invention, it is possible to set an appropriate purge time for supplying a desired amount of fuel and an appropriate start crank angle for ensuring the purge time.

Embodiment 1 FIG.
[Configuration of Embodiment 1]
FIG. 1A is a diagram for explaining the mechanical configuration of the first embodiment of the present invention. FIG. 1B is a diagram for explaining the electrical configuration of the system of the present embodiment. As shown in FIG. 1A, the system of this embodiment includes an internal combustion engine 10. The internal combustion engine 10 includes a plurality of cylinders. Hereinafter, for convenience of explanation, it is assumed that the internal combustion engine 10 is a four-cylinder engine.

  The four cylinders each incorporate an intake valve 12 that opens and closes an intake port and an exhaust valve 14 that opens and closes an exhaust port. FIG. 1A shows one of these cylinders. A branch pipe of the intake manifold 16 communicates with the intake port of each cylinder. The branch pipes for four cylinders gather at one end and communicate with the surge tank 18. A throttle valve 20 for controlling the conduction state of the intake passage is disposed upstream of the surge tank 18.

  The internal combustion engine 10 includes a fuel injection valve 22 for each cylinder. The fuel injection valve 22 can inject fuel into the intake port of each cylinder. A purge passage 24 communicates with the vicinity of the intake port. The purge passage 24 is prepared for each cylinder, and each has a D-VSV 26. The D-VSV 26 is a control valve that opens and closes in response to a duty signal. According to the D-VSV 26, the conduction state of the purge passage 24 can be substantially controlled.

  The purge passages 24 for the four cylinders all communicate with the canister 28. The canister 28 incorporates activated carbon therein, and includes a vapor inflow hole 30 and an air hole 32. The vapor inflow hole 30 communicates with the fuel tank via a vapor passage (not shown). The air holes 32 communicate with the atmosphere as shown in FIG.

  Inside the fuel tank, there is a gas containing evaporated fuel. This gas flows into the canister 28 from the vapor inflow hole 30 when refueling, for example. At this time, the canister 28 adsorbs the evaporated fuel contained in the gas and causes only the air to flow out from the atmospheric hole 32. As a result, the canister 28 is in a state where the evaporated fuel is adsorbed.

  The system of this embodiment can appropriately open the D-VSV 26 of each cylinder during the operation of the internal combustion engine 10. While the internal combustion engine 10 is in operation, intake negative pressure is generated. When the D-VSV 26 is opened, the negative pressure is guided to the canister 28. As a result, a flow of air flowing in from the atmospheric hole 32 is generated inside the canister 28, and the evaporated fuel is purged by the flow of air. In the system of this embodiment, the evaporated fuel adsorbed by the canister 28 can be caused to flow into the individual cylinders in this way.

  As shown in FIG. 1B, the system of the present embodiment includes an ECU (Electronic Control Unit) 40. An ignition switch (IG) 42, a starter switch 44, a crank angle sensor 46, and a water temperature sensor 48 are connected to the ECU 40. The ECU 40 is connected to a D-VSV 26 disposed in the # 1 cylinder to the # 4 cylinder.

  The crank angle sensor 46 generates a pulse signal every time the crankshaft rotates 30 ° CA, and when the # 1 cylinder piston passes the intake top dead center, and the # 4 cylinder piston indicates the intake top dead center. When passing, a cylinder discrimination signal is generated. When the ECU 40 receives the cylinder discrimination signal indicating that the # 4 cylinder has reached the intake top dead center after the internal combustion engine 10 is started, the ECU 40 recognizes that the crank angle is 0 ° CA. When the cylinder discrimination signal indicating that the # 1 cylinder has reached the intake top dead center is received, the crank angle is recognized as 360 ° CA at that time. Hereinafter, this recognition of the crank angle is referred to as “cylinder discrimination”.

  As described above, the ECU 40 can finish the cylinder discrimination at the timing when the # 1 cylinder or the # 4 cylinder reaches the intake top dead center after the internal combustion engine 10 is started. When the cylinder discrimination is completed, the ECU 40 can continue to specify the rotational position of the crankshaft by counting the pulse signals generated every 30 ° CA thereafter.

[Operation of Embodiment 1]
Normally, the internal combustion engine 10 is started in a situation where the internal combustion engine 10 is not warmed up. Under such circumstances, since the fuel is difficult to vaporize, when the fuel is injected from the fuel injection valve 22, a situation occurs in which part of the fuel remains in a liquid state and does not contribute to combustion. On the other hand, if the fuel adsorbed by the canister 28 is purged and supplied to the internal combustion engine 10, the already vaporized fuel can be supplied, and good combustibility can be obtained even in a low temperature environment.

  For this reason, the system of the present embodiment realizes a desired fuel supply by stopping the fuel supply by the fuel injection valve 22 and purging the evaporated fuel in the canister 28 when the internal combustion engine 10 is started. . More specifically, the system of the present embodiment sequentially opens the D-VSV 26 arranged for each cylinder while the fuel injection valve 22 is closed when the internal combustion engine 10 is started, so that an appropriate amount is provided for each cylinder. It was decided to supply evaporative fuel.

(First comparative example: 180 ° CA delay control)
FIG. 2 is a timing chart for explaining the operation of the first comparative example. The operation of the first comparative example is an example of an operation that can be realized by the system shown in FIG. Here, in order to clarify the aim of the system of the present embodiment, the operation of the first comparative example will be described prior to the operation actually realized in the present embodiment.

  More specifically, FIG. 2A shows the waveform of the intake pipe pressure MV immediately after the start of the internal combustion engine 10. FIG. 2B shows a waveform of the engine speed NE immediately after starting. FIG. 2C is a diagram for explaining the transition of the stroke in each cylinder. FIG. 2D is a diagram for explaining a purge rule used in the first comparative example.

  As shown in FIG. 2 (B), the engine speed NE is kept at a very low speed until cranking by the starter motor is started and after the first explosion is obtained. It rises rapidly up to the rotation speed. Further, as shown in FIG. 2A, the intake pipe negative pressure MV pulsates in the vicinity of the atmospheric pressure until the engine speed NE rises after cranking is started, and reaches the engine speed NE. After the rise occurs, the pressure starts to decrease significantly.

  In order to supply the evaporated fuel in the canister 28 to each cylinder when the internal combustion engine 10 is started, the D-VSV 26 corresponding to the cylinder is opened in synchronization with the intake stroke of the individual cylinder. desirable. In order to perform such control, the ECU 40 knows what state each cylinder is in. That is, the ECU 40 finishes the cylinder discrimination and knows the rotational position of the crankshaft. It is necessary to be.

  The ECU 40 includes a crank angle counter CCRNK in order to grasp the rotational position of the crankshaft during operation of the internal combustion engine 10. When the cylinder discrimination signal indicating that the # 4 cylinder has reached the intake top dead center is recognized after the internal combustion engine 10 is started, the crank angle counter CCRNK recognizes a value corresponding to 0 ° CA (specifically, “ 0 "). Further, when the cylinder discrimination signal indicating that the # 1 cylinder has reached the intake top dead center is issued first after the internal combustion engine 10 is started, CCRNK is set to a value corresponding to 360 ° CA at that time.

  After the CCRNK is set to the above value, it is counted up every time a pulse signal is issued from the crank angle sensor 46 every 30 ° CA. When the crank angle reaches 720 ° CA, that is, when the # 4 cylinder reaches the intake top dead center, it is reset to zero at that time. For example, if the # 4 cylinder reaches the intake top dead center earlier than the # 1 cylinder after cranking starts, the waveform of CCRNK ranges from 0 to a value corresponding to 720 ° CA as shown in FIG. And a continuous triangular waveform composed of repetition of a reset from 720 ° CA corresponding value to 0.

  As shown in FIG. 2 (C), in the internal combustion engine 10, in a process where CCRNK is counted up from 0 to 720 ° CA, every time the crank angle changes by 180 °, # 4 cylinder → # 2 cylinder The intake stroke is performed in the order of # 1 cylinder → # 3 cylinder. In order to inhale the desired evaporative fuel in those intake strokes, the purge time (time for opening the D-VSV 26) required to purge the desired evaporative fuel is set before the end of each intake stroke. It is necessary to secure.

  A region indicated by hatching in FIG. 2D indicates a period during which the intake stroke is executed in each cylinder. Also, the white arrow shown in FIG. 2D indicates the purge period of each cylinder set in the first comparative example, that is, the period during which the D-VSV 26 of each cylinder opens. . Here, specifically, the D-VSV 26 of each cylinder always opens at a crank angle advanced by 180 ° CA from the crank angle at which the intake stroke is started in each cylinder, and then the desired amount The valve is set to open only for the purge time required for the fuel supply.

  After the start of the internal combustion engine 10 is started, while the intake pipe pressure MV is not sufficiently negative, the suction force guided to the canister 28 is small, so that it is sufficient to purge the desired amount of evaporated fuel. A long purge time is required. More specifically, at this stage, a purge time longer than the execution time of the intake stroke is required to suck an appropriate amount of evaporated fuel into each cylinder. In this case, in order to finish the purge before the end of the intake stroke, it is necessary to set the start time of the purge time to a time earlier than the time when the intake stroke is started.

  As described above, the ECU 40 recognizes that the # 4 cylinder or the # 1 cylinder has reached the intake top dead center when the cylinder discrimination signal is received. Therefore, the ECU 40 already knows the state of the internal combustion engine 10 when the first intake stroke is started in the # 4 cylinder or when the first intake stroke is started in the # 1 cylinder. However, for the reason described above, in the stage immediately after the start, if the purge is started together with the start of the intake stroke, a sufficient amount of evaporated fuel cannot be caused to flow into the cylinder by the intake stroke. If insufficient evaporative fuel is allowed to flow into the cylinder, proper combustion may not be obtained and the emission characteristics may deteriorate.

  For this reason, in the system shown in FIG. 1, after starting the internal combustion engine 10, the cylinder that can be purged first is the cylinder that starts the intake stroke first after the cylinder discrimination is completed. . That is, when the cylinder discrimination signal corresponding to the # 4 cylinder appears first, the # 2 cylinder becomes the cylinder that can be purged first. When the cylinder discrimination signal corresponding to the # 1 cylinder appears first, the # 2 cylinder becomes the cylinder that can be purged first.

  In order to complete the start-up of the internal combustion engine 10 in a short time, it is desirable to execute the initial fuel supply to the cylinder as soon as possible. For the above reason, the first comparative example is an operation example in which the # 2 cylinder or the # 3 cylinder in which the intake stroke is first performed after the cylinder discrimination signal is generated is the first purge cylinder. Here, purging of individual cylinders is started simultaneously with the generation of the cylinder discrimination signal so that the purging of these cylinders can be started at the earliest possible time.

  In other words, in the first comparative example, the D-VSV 26 corresponding to the # 2 cylinder or the # 3 cylinder is opened at the same time as the cylinder discrimination signal is generated. The valve is closed. In this case, the purge for the # 2 cylinder or the # 3 cylinder is started at a crank angle advanced by 180 ° CA from the crank angle at which the intake stroke is started in those cylinders. Thereafter, in the first comparative example, purging is started in accordance with the above rules, that is, at a crank angle advanced by 180 ° CA from the start crank angle of intake air, and thereafter, when an appropriate purge time has elapsed, the D-VSV 26 Purging is performed for all the cylinders according to the rule of closing.

  In the example shown in FIG. 2, after the internal combustion engine 10 is started, a cylinder discrimination signal is generated at the intake top dead center of the # 4 cylinder. In this case, as shown in FIG. 2 (D), the purge for the # 2 cylinder is started at that time, and then the intake stroke of the # 2 cylinder is started when the crankshaft rotates 180 ° CA. Thereafter, every time the crankshaft rotates by 180 ° CA, the intake stroke is started in the order of # 1 cylinder → # 3 cylinder → # 4 cylinder. Then, in the # 2 cylinder that is purged first, as shown in FIG. 2 (C), an explosion stroke is performed when the intake stroke is executed in the # 3 cylinder.

  That is, according to the first comparative example, the initial explosion of the internal combustion engine 10 is obtained at the time when the intake stroke corresponding to the third purge is executed after the start of the internal combustion engine 10 is started. Then, when the intake stroke corresponding to the fourth purge is executed, the second explosion is obtained, and a rapid rise appears in the engine speed NE.

  As shown in FIGS. 2 (A) and 2 (B), the intake pipe pressure MV becomes negative with a delay with respect to the rise of the engine speed NE. For this reason, in the stroke in which the first explosion occurs in the internal combustion engine 10, that is, the stroke in which intake is performed in the # 3 cylinder, only the engine speed NE is increased while the intake pipe pressure MV is maintained at a value close to atmospheric pressure. Things happen.

  If the intake pipe pressure MV is maintained at a value close to atmospheric pressure, a purge time equivalent to that immediately after the start of startup is required to purge the desired amount of evaporated fuel. On the other hand, if the engine speed NE is increased, the time required for the crank angle to change by 180 ° CA is shorter than before. For this reason, according to the first comparative example, as shown in FIG. 2 (D), at the time of the first intake in the # 3 cylinder, the end time of the purge time may be later than the end time of the intake stroke. Arise.

  The # 3 cylinder cannot inhale the evaporated fuel purged after the end of the intake stroke. For this reason, sufficient vaporized fuel cannot be supplied to the # 3 cylinder under the above situation. According to the example shown in FIG. 2, after the intake stroke of the # 3 cylinder is completed, the explosion stroke of the # 3 cylinder is started when the crank angle changes by 180 ° CA. At this time, the # 3 cylinder cannot generate a sufficient torque because the fuel supply amount is insufficient. As a result, the engine speed NE is likely to be slack as shown in FIG.

  In the case of the first comparative example, it also occurs in the # 4 cylinder where the fourth purge is performed. That is, according to the example shown in FIG. 2, the intake pipe pressure MV is maintained at a value close to the atmospheric pressure at the time when the fourth purge is started in the # 4 cylinder. For this reason, a sufficiently long purge time is set for the fourth purge.

  However, in the internal combustion engine 10, the first explosion occurs simultaneously with the start of the fourth purge, and further, the second explosion occurs while the purge continues. For this reason, the rotational speed of the crank angle is remarkably increased after the fourth purge is started. As a result, as shown in FIG. 2D, the purge time end timing is also delayed from the intake stroke end timing in the fourth purge.

  As described above, according to the first comparative example, the end time of the purge time is later than the end time of the intake stroke at the time of the initial explosion when the engine speed NE rises and immediately after the occurrence. Arise. For this reason, the internal combustion engine 10 cannot always be started smoothly by opening the D-VSV 26 according to the first comparative example.

(Second comparative example: 360 ° CA delay control)
In the first comparative example, at the time of the third and fourth purges, the purge end point is later than the intake stroke end point because the start of the purge is too late. For this reason, as a means for preventing the occurrence of the above situation, for example, it is conceivable to further advance the purge start crank angle as compared with the case of the first comparative example.

  FIG. 3 is a timing chart for explaining the operation of the second comparative example in which the purge start crank angle is further advanced by 180 ° CA compared to the case of the first comparative example from the above viewpoint. 3 (A) to 3 (D) correspond to FIGS. 2 (A) to 2 (D), respectively. Intake pipe pressure MV, engine speed NE, stroke change in each cylinder, and The purge rule used in the second comparative example is shown.

  As described above, in the second comparative example, the purge start crank angle is further advanced by 180 ° CA compared to the case of the first comparative example. That is, in the second comparative example, the purge start crank angle is set to an angle advanced by 360 ° CA from the crank angle at which purge is started in each cylinder.

  In the system shown in FIG. 1, after the cylinder discrimination signal indicating the intake top dead center of the # 4 cylinder is generated, the intake stroke of the # 1 cylinder is started when the crankshaft is rotated by 360 ° CA. In addition, after the cylinder discrimination signal indicating the intake top dead center of the # 1 cylinder is generated, the intake stroke of the # 4 cylinder is started when the crankshaft rotates by 360 ° CA. For this reason, in the case of the second comparative example, after starting the internal combustion engine 10, the cylinder that can be properly purged first is the # 1 cylinder or the # 4 cylinder.

  In the example shown in FIG. 3, after the internal combustion engine 10 is started, the cylinder discrimination signal is generated at the intake top dead center of the # 4 cylinder. In this case, as shown in FIG. 3D, the purge for the # 1 cylinder is started at that time, and thereafter, the intake stroke of the # 1 cylinder is started when the crankshaft rotates 360 ° CA. Thereafter, every time the crankshaft rotates 180 ° CA, the intake stroke starts in the order of # 3 cylinder → # 4 cylinder → # 2 cylinder. In the # 1 cylinder that is purged first, as shown in FIG. 3C, an explosion stroke is performed when the intake stroke is executed in the # 4 cylinder.

  In the case of the second comparative example, until the third purge, the period during which the crankshaft rotates at an extremely low speed can be secured over 360 ° CA before the intake stroke is started. For this reason, unlike the case of the first comparative example, for the third purge, the purge can be terminated before the intake stroke is completed.

  However, even in the second comparative example, in the fourth purge, as shown in FIG. 3D, the purge end timing is delayed from the intake end timing (see # 2 cylinder). That is, even if the purge start timing is advanced by 180 ° CA compared to the case of the first comparative example, with respect to the fourth purge, as the engine speed NE rises, before the end of the intake stroke In other words, the desired purge time cannot be secured. For this reason, even when the D-VSV 26 is opened according to the second comparative example, the internal combustion engine 10 cannot always be started smoothly.

  In other words, as long as the method of opening the D-VSV 26 arranged in each cylinder at an angle advanced by a predetermined advance amount from the start angle of the intake stroke, the advance amount is set to any value. Even so, the several purges are inevitably started immediately before the rise of the engine speed NE occurs. Such purging is performed in an environment in which the intake pipe negative pressure MV is maintained at a value close to atmospheric pressure and only the rotational speed of the crankshaft is increased, and thus is always continued until after the end of the intake stroke. It will be. Therefore, it is difficult to start the internal combustion engine 10 smoothly by a method of always setting the purge start crank angle under the same conditions with the start angle of the intake stroke as a reference.

(Operation of Embodiment 1)
By the way, when the D-VSV 26 is operated according to the first comparative example or the second comparative example, the purge end timing is later than the intake stroke end timing at the same time as the first explosion or the first explosion. It is limited to the purge performed immediately after. In other words, in the case of the first comparative example, the purge that cannot be performed properly is limited to the third purge that is executed in response to the intake stroke performed simultaneously with the first explosion and the fourth purge that is performed immediately thereafter. It is done. Further, in the case of the second comparative example, the purge that cannot be performed properly is limited to the fourth purge that is executed in response to the intake stroke started after the first explosion.

  In other words, when the D-VSV 26 arranged for each cylinder is operated in synchronism with the crank, if the rule for opening the D-VSV 26 is determined, a purge that cannot be performed properly will cause the first explosion. In other words, it can be specified in advance in relation to the timing to perform, in other words, in relation to the number of purges executed after the internal combustion engine 10 is started. If only the purge specified in this way is advanced in the starting crank angle compared to other purges, it is possible to end all purges before the end of the intake stroke. .

  FIG. 4 is a timing chart for explaining the operation in the present embodiment for realizing the above function. 4 (A) to 4 (D) correspond to FIGS. 2 (A) to 2 (D), respectively, and the intake pipe pressure MV, the engine speed NE, and the transition of the stroke in each cylinder, respectively. , And the purge rules used in the second comparative example.

  The system of this embodiment executes the first purge and the second purge in the same manner as in the first comparative example. For example, when the cylinder discrimination signal indicating that the # 4 cylinder has reached intake top dead center after the internal combustion engine 10 is started is generated first, as shown in FIG. Start purge of 2 cylinders. Next, when the crank angle changes by 180 ° CA and the intake stroke is started in the # 2 cylinder, the purge for the # 1 cylinder is started.

  The first explosion in the # 2 cylinder occurs after the intake stroke of the # 1 cylinder ends. For this reason, while the intake strokes are sequentially performed in the # 2 cylinder and the # 1 cylinder, the engine speed NE is maintained at an extremely low speed. As a result, for the first purge and the second purge, a sufficient purge time can be secured before the end of the intake stroke.

  In the system of the present embodiment, the start crank angle of the third purge is advanced by 90 ° CA compared to the first and second start crank angles. That is, the third purge is started at a crank angle advanced by 270 ° CA from the starting point of the intake stroke corresponding to the purge.

  According to the example shown in FIG. 4, the third purge and the intake stroke corresponding to the purge are performed in the # 3 cylinder. When the intake stroke is performed in the # 3 cylinder, the first explosion occurs in the # 2 cylinder as shown in FIG. As a result, the time required for the intake stroke in the # 3 cylinder is shortened compared to the time required for the intake stroke executed before that time.

  However, in the third purge, as described above, the start crank angle is advanced by 90 ° CA compared to the first or second purge. For this reason, although the time required for the corresponding intake stroke is shortened, the third purge can be properly terminated after securing the desired purge time before the intake stroke is completed.

  In the system of this embodiment, for the fourth purge, the starting crank angle is advanced by 90 ° CA compared to the third purge, that is, compared to the first and second purges. The angle is advanced by 180 ° CA. Therefore, the fourth purge is started at a crank point advanced by 360 ° CA from the start point of the intake stroke corresponding to the purge.

  According to the example shown in FIG. 4, the fourth purge and the intake stroke corresponding to the purge are performed in the # 1 cylinder. In the internal combustion engine, the first explosion occurs when the # 1 cylinder reaches a crank angle of 180 ° CA before the start of the first intake stroke. Further, the second explosion occurs at the same time as the intake stroke is started in the # 1 cylinder. Therefore, for the # 1 cylinder, the time from 180 ° CA before the start of the intake stroke to the end of the intake stroke is significantly shorter than in the case of the first or second purge.

  However, in the fourth purge, as described above, the start crank angle is advanced by 180 ° CA compared to the first or second purge. Therefore, according to the system of the present embodiment, as shown in FIG. 4D, the fourth purge is also properly terminated after securing a sufficient purge time before the intake stroke is completed. be able to.

  In the system of the present embodiment, for the fifth and subsequent purges, similarly to the first and second purges, the purge is started at 180 ° CA before the start of the corresponding intake stroke. The fifth and subsequent purges are executed when the engine speed NE rises and the intake pipe negative pressure MV becomes negative to some extent. Under such circumstances, it is possible to supply a sufficient amount of evaporated fuel with a short purge. For this reason, with respect to the fifth and subsequent purges, a sufficient purge time can always be ensured before the opposite intake stroke ends due to the above conditions.

  As described above, according to the system of this embodiment, the purge start timing is advanced for the third purge and the fourth purge, so that all the purges are performed before the end of the intake stroke. The condition of ensuring a sufficient purge time can be satisfied. For this reason, according to the system of the present embodiment, the internal combustion engine 10 can be started very smoothly while using a technique using evaporated fuel.

[Specific Processing in Embodiment 1]
FIG. 5 is a flowchart of the start purge control executed by the system of the present embodiment. The operation described above is realized by the ECU 40 executing the routine shown in FIG. In the routine shown in FIG. 5, it is first determined whether or not the IG switch 42 is on (step 100). As a result, when it is determined that the IG switch 42 is not turned on, it can be determined that the stop of the internal combustion engine 10 is required. In this case, the purge of the evaporated fuel is immediately stopped (step 102), and then the current processing cycle is immediately terminated.

  If it is determined in step 100 that IG is on, it is next determined whether or not cranking is being performed in the internal combustion engine 10 based on the state of the starter switch 44 (step 104). As a result, when it is determined that cranking is being performed, the start mode setting process is performed (step 106).

  The start mode is a mode for smoothly starting the internal combustion engine 10. Therefore, it is not necessary to set the start mode in a situation where cranking is not performed. Therefore, if it is determined in step 104 that cranking has not been executed, the process of step 106 is jumped.

  Specifically, the start mode setting process executed in step 106 is executed according to the routine shown in FIG. The routine shown in FIG. 6 is for setting the start mode flag when it is recognized that it is necessary to continue the start purge control by using only the evaporated fuel supplied from the canister 28 to cover the fuel necessary for the start. It is.

  In the routine shown in FIG. 6, it is first determined whether or not the evaporated fuel is sufficiently adsorbed inside the canister 28 (step 110). The ECU 40 detects or estimates the amount of adsorption in the canister 28 by a known method. Specifically, for example, the fuel concentration of the purge gas flowing out from the canister 28 during operation of the internal combustion engine 10 is learned, and the adsorption amount of the evaporated fuel is estimated based on the fuel concentration. Here, the estimated value is read, and it is determined whether or not the amount of adsorption exceeding the predetermined determination value has occurred.

  If it is determined that the adsorbed amount of the evaporated fuel exceeds the determination value, it can be determined that the start with the purge gas is possible. In this case, it is next determined whether or not the internal combustion engine 10 is idling (step 112).

  When the internal combustion engine 10 is not in idle operation, it can be determined that a large intake air amount GA has occurred through the throttle valve 20. Under such circumstances, it is difficult to obtain an appropriate air-fuel ratio with only the evaporated fuel flowing out of the canister 28. On the other hand, during idle operation, it can be determined that the intake air amount GA is small and a desired air-fuel ratio can be obtained with only evaporated fuel. If it is determined in this way, it is further determined whether or not the integrated amount of the intake air amount GA generated after the start of the internal combustion engine 10 (hereinafter referred to as “integrated air amount GASUM”) exceeds the determination value. (Step 114).

  In the present embodiment, the purge of the evaporated fuel is started immediately after the internal combustion engine 10 is started. For this reason, there is a certain degree of correlation between the accumulated purge amount of evaporated fuel and the accumulated air amount GASUM. When the integrated air amount GASUM exceeds the determination value, it can be determined that the purge of the canister 28 has progressed to a considerable extent, and there is a possibility that a sufficient amount of adsorption does not remain inside. On the other hand, when the accumulated air amount GASUM is less than the determination value, it can be determined that the purge of the evaporated fuel has not progressed so much and a sufficient adsorption amount is secured in the canister 28.

  If the latter determination is made, it is next determined whether the integrated value (integrated NE) of the engine speed NE measured after the start exceeds the determination value (step 116). Next, it is determined whether the operation time after starting exceeds the determination time (step 118). And when these judgments are denied, it can be judged that sufficient adsorption amount is ensured for the same reason as the case where the judgment of step 114 is denied. If such a determination is obtained, it is further determined whether or not the catalyst has been warmed up (step 120).

  A catalyst for purifying exhaust gas is disposed in the exhaust passage of the internal combustion engine 10. This catalyst is warmed up by the exhaust heat after the internal combustion engine 10 is started, and when it reaches a predetermined activation temperature, it starts to exhibit the exhaust gas purification action. After the catalyst starts to exert a purification action, the exhaust emission does not deteriorate even if a slight air-fuel ratio shift occurs. For this reason, after the catalyst is activated, it is not always necessary to stop the fuel injection from the fuel injection valve 22, that is, the start-time purge control need not be continued. On the other hand, while the catalyst warm-up has not been completed, it is effective to continue the startup purge control in order to obtain good emission characteristics.

  If it is determined in step 120 that the catalyst has not been warmed up, that is, if it is determined that there is still a need to perform start-up purge control, the current intake air amount GA further exceeds the determination value. It is determined whether or not (step 122). As a result, if it is determined that the GA does not exceed the determination value, it is determined that the conditions for executing the start purge control are satisfied, and the start mode execution flag is set (step 124).

  On the other hand, when the condition of step 110 or 112 is not satisfied, or when any of the conditions of steps 114 to 122 is satisfied, the condition for executing the start-time purge control is ready. It is judged that it is not. In this case, the start mode flag is turned off (step 126).

  When the above processing is completed, it is next determined in the routine shown in FIG. 5 whether or not the engine is in the start mode. Specifically, it is determined whether the start mode flag is on (step 130). As a result, when it is determined that the start mode flag is not ON, normal fuel injection control, that is, control for supplying fuel to the internal combustion engine 10 mainly by the fuel injection valve 22 is executed (step). 132).

  On the other hand, if it is determined in step 130 that the start mode flag is ON, the purge time TPG setting process is then executed (step 134). The purge time TPG needs to be set to a time during which a desired amount of evaporated fuel can be supplied to each cylinder. The time varies depending on the intake pipe pressure MV when purging is performed.

  As shown in FIG. 4A, the intake pipe pressure MV is maintained at a value close to the atmospheric pressure until the first explosion occurs, and becomes significantly negative as the engine speed NE rises with the occurrence of the first explosion. . And what value the intake pipe pressure MV takes when each purge is performed can be grasped in advance in relation to the number of purge executions. If the relationship can be grasped in advance, the purge time required for each purge can be set in advance in relation to the number of purges.

  In the present embodiment, the ECU 40 stores a map that defines the relationship between the purge time and the number of purges according to the above principle. Further, the ECU 40 has a counter that counts the number of purges that have been performed after the start of the internal combustion engine 10 is started. In step 134, the purge time TPG for the current purge is set by reading the purge time TPG corresponding to the count value of the counter from the map.

  In the routine shown in FIG. 5, next, the purge advance amount CRNKPG is set (step 136). The purge advance amount CRNKPG is a value that determines how much the purge start crank angle CRNKPGS is advanced relative to the intake stroke start crank angle (intake CRNK). As shown in the frame of step 136, the ECU 40 stores a map that defines the relationship between the number of purges and the purge advance amount CRNKPG.

  Specifically, this map is determined so that the purge advance amount CRNKPG is “180 ° CA” when “the number of purges + 1” is 1, 2 or 5 or more. Further, when “the number of purges + 1” is 3, the purge advance amount CRNKPG is “270 ° CA”, and when the value is 4, the purge advance amount CRNKPG is “360 ° CA”. Is set to be.

  According to the above map, the purge advance amount CRNKPG is set to “180 ° CA” at the timing at which the first or second purge or the fifth and subsequent purges should be executed. Then, CRNKPG is determined to be “270 ° CA” at the timing at which the third purge is to be executed, and CRNKPG is determined to be “360 ° CA” at the timing at which the fourth purge is to be performed.

In the routine shown in FIG. 5, next, the purge start angle CRNKPGS is set according to the following arithmetic expression (step 138).
CRNKPGS = Intake CRNK-CRNKPG (1)

  According to the above processing, after the start of the internal combustion engine 10, the individual cylinders are purged at the timing shown by the white arrow in FIG. 4D in synchronization with the rotation of the crank angle. It can be carried out. For this reason, according to the system of the present embodiment, when the internal combustion engine 10 is started, the evaporated fuel can be properly supplied to the individual cylinders, and as a result, the internal combustion engine 10 can be started smoothly. it can.

  By the way, in the first embodiment described above, the first, second, and fifth purges are started at a crank angle advanced by 180 ° CA from the start point of the intake stroke, as in the case of Comparative Example 1. However, the present invention is not limited to this. That is, as in the case of the comparative example 2, those purges may be started at a crank angle advanced by 360 ° CA from the starting point of the intake stroke.

  In the first embodiment described above, the D-VSV 26 corresponds to the “purge control valve” in the first aspect of the invention, and the ECU 40 performs D according to the rules determined by the processing of steps 134 to 138. -By opening / closing the VSV 26, the "control valve driving means" in the first invention performs the processing in step 138, and the "purge start angle setting means" in the first invention performs the processing in step 136. By executing the processing, the “advance amount setting means” according to the first aspect of the present invention is realized.

  In the first embodiment described above, the counter for counting the number of purges corresponds to the “purge number counting means” in the third aspect of the invention, and the ECU 40 is shown in the frame of step 136. By storing the map, the “rule storage means” in the third invention realizes the “setting means” in the third invention by executing the processing of step 136.

Embodiment 2. FIG.
[Features of Embodiment 2]
Next, a second embodiment of the present invention will be described with reference to FIG. The system of the present embodiment can be realized by causing the ECU 40 to execute a routine shown in FIG. 7 described later instead of the routine shown in FIG. 5 described above in the system of the first embodiment.

  In the system of the first embodiment described above, the purge advance amount CRNKPG is set with reference to the map (see step 136 above). However, the method for setting the purge advance amount CRNK is not limited to this. That is, the purge advance amount CRNKPG that satisfies the rule of FIG. 4D prepares, for example, a standard value (for example, 180 ° CA) of the purge advance amount CRNKPG and a correction coefficient KP (for example, 2.0) in advance. The standard value can be used in the first and second purges, and the standard value can be set appropriately in the third and fourth purges by using a value obtained by correcting the standard value with the correction coefficient KP. is there.

  In the first embodiment described above, the purge time TPG is set based only on the number of purges. However, the amount of fuel required when starting the internal combustion engine 10 varies depending on, for example, the warm-up state of the internal combustion engine 10, that is, the cooling water temperature THW. For this reason, the purge time TPG may be corrected based on the cooling water temperature THW, for example.

  The purge advance amount CRNKPG needs to be set so that the purge time TPG can be secured before the end of the intake stroke. Therefore, if the purge time TPG is extended, it is necessary to increase the purge advance amount CRNKPG. That is, when the purge time TPG is corrected based on, for example, THW, it is necessary to appropriately correct the purge advance amount CRNKPG in accordance with the correction.

  For this reason, in the present embodiment, the purge advance amount CRNKPG is calculated by calculation using the standard value of the purge advance amount CRNKPG and the correction coefficient KP without using a map. In the present embodiment, appropriate correction is made to the purge time TPG and the purge advance amount CRNKPG based on the coolant temperature THW.

[Specific Processing in Second Embodiment]
FIG. 7 is a flowchart of a routine executed by the ECU 40 in the present embodiment in order to realize the above function. The routine shown in FIG. 7 is the same as the routine shown in FIG. 5 except that step 136 is replaced with steps 140 to 148. In FIG. 7, the same steps as those shown in FIG. 5 are denoted by the same reference numerals, and the description thereof is omitted or simplified.

  That is, according to the routine shown in FIG. 7, the purge time TPG is corrected after the purge time TPG is set in step 134 (step 140). In step 134, on the assumption that the coolant temperature THW is the reference temperature, a reference value for the purge time TPG is calculated. When the temperature of the internal combustion engine 10 is lower than the reference temperature, it is desirable to increase the fuel supply amount at the start in order to cope with an increase in friction and the like. For this reason, in step 140, correction processing is executed so that the purge time TPG is extended as the coolant temperature THW is lower.

  As shown in the frame of step 140, the ECU 40 stores a map that defines the correction time ΔTPG in relation to the cooling water temperature. More specifically, this map is set so that ΔTPG is 0 in a region where the coolant temperature THW exceeds the reference temperature THW0, and ΔTPG becomes a larger value as THW is lower in a region below it. In step 140, the correction time ΔTPG read with reference to this map is added to the reference value for the purge time TPG. According to the above processing, it is possible to extend the purge time TPG as the cooling water temperature THW is lower and increase the fuel supply amount at the time of start-up.

  When the above processing is completed, the purge advance angle reference value tCRNKPG is set (step 142). The purge advance amount reference value tCRNKPG is the purge advance amount CRNKPG used in the first, second, or fifth and subsequent purges. That is, it is the purge advance amount CRNKPG used for the purge that is not affected by the rise of the engine speed NE and does not need to advance the start timing specially.

  In the first embodiment described above, the purge advance amount CRNKPG is always set to 180 ° CA. In contrast, in the present embodiment, since the purge correction is performed on the purge time TPG based on the coolant temperature THW, the purge advance amount reference value tCRNKPG is also set based on THW.

  As shown in the frame of step 142, the ECU 40 stores a map of tCRNKPG set in relation to the coolant temperature THW. This map is set so that the purge advance angle reference value tCRNKPG becomes larger as the coolant temperature THW is lower. The purge advance amount reference value tCRNKPG is a reference value of the crank angle that is secured between the purge start point and the intake stroke start point. Therefore, when the purge start timing is set according to the reference value, the time required for the crankshaft to rotate by the purge advance amount reference value tCRNKPG before the intake stroke is started (hereinafter referred to as “pre-intake purge”). The purging period is ensured only by “time”.

  More precisely, the map used in step 142 has a purge advance amount reference value tCRNKPG that is related to the coolant temperature THW so that the purge time before intake air expands corresponding to the correction time ΔTPG. It has been established. According to such a map, the purge advance angle reference value tCRNKPG can be determined so that the correction time ΔTPG can be absorbed by the pre-intake purge time. According to such a setting, regardless of the extension of the purge time TPG, the purge time can be reliably ended before the end of the intake stroke.

  In the routine shown in FIG. 7, it is next determined whether the purge to be executed this time is a specific number of purges, that is, whether the purge start crank angle needs to be advanced in advance (see FIG. 7). Step 144). In the system according to the present embodiment, in step 144, specifically, it is determined whether the current purge is the third or fourth purge.

  As a result, if it is determined that the current purge is not a specific number of purges (that is, the first, second, or fifth and subsequent purges), the purge advance reference value tCRNKPG is used as is for the current purge. The advance amount is CRNKPG (step 146). Thereafter, the process of step 138 is executed, and the point advanced by the purge advance angle reference value tCRNKPG from the start point of the intake stroke becomes the purge start point.

On the other hand, if it is determined in step 144 that the current purge is a specific number of purges (that is, the third or fourth purge), the current purge advance amount CRNKPG is calculated according to the following equation. (Step 148).
CRNKPG = tCRNKPG * KP (2)

  The correction coefficient KP is a value larger than 1.0, and is 2.0 in the present embodiment. Therefore, according to the above equation (2), the purge advance amount CRNK is set to a value about twice the purge advance amount reference value tCRNKPG. Therefore, according to the system of the present embodiment, the purge start crank angle CRNKPGS can be sufficiently advanced for the third and fourth purges performed at the same time as the first explosion, and as a result, the internal combustion engine 10 Can be started smoothly.

  In the second embodiment described above, the “advance amount setting means” according to the first aspect of the present invention is realized by the ECU 40 executing the processing of steps 142 to 148. Further, the ECU 40 stores the map shown in the frame of step 142, and stores the third and fourth purges as a specific number of purges, whereby the “rule storage means” in the third invention is provided. The “setting means” in the third aspect of the present invention is realized by setting the purge advance amount CRNKPG by the processes of steps 142, 146 and 148, respectively.

  In the second embodiment described above, the ECU 40 executes the processing of step 140, whereby “purge time correcting means” in the fourth invention and “correcting means for increasing the purge time” in the fifth invention. ”Is realized by executing the processing of step 142, respectively, in the“ advancing amount correcting means ”in the fourth invention and“ correcting means for increasing the purge advance amount ”in the fifth invention. .

Embodiment 3 FIG.
Next, a third embodiment of the present invention will be described with reference to FIG. The system of the present embodiment can be realized by causing the ECU 40 to execute a routine shown in FIG. 8 described later in place of the routine shown in FIG. 5 described above in the system of the first embodiment. The system of the present embodiment is the same as the system of the second embodiment except that the purge start crank angle is set with reference to a map.

  FIG. 8 is a flowchart of a routine executed by the ECU 40 in the present embodiment. The routine shown in FIG. 8 is the same as the routine shown in FIG. 7 except that steps 142 to 146 are replaced by steps 150 and 152. Hereinafter, among the steps shown in FIG. 8, the same steps as those shown in FIG. 7 are denoted by the same reference numerals, and the description thereof is omitted or simplified.

  In the routine shown in FIG. 8, after the purge time TPG is corrected in step 140, a map number to be used in the current processing cycle is set (step 150). The system of the present embodiment corrects the purge time TPG based on the cooling water temperature THW, as in the case of the second embodiment described above. The system according to the present embodiment displays a map that defines the relationship between the purge advance amount CRNKPG and the number of purges so that the purge advance amount CRNKPG can be extended in accordance with the extension of the purge time TPG. Multiple THW parameters are stored.

  Each of these maps is given a number. As shown in the frame of step 150, the ECU 40 stores a number setting map that defines the relationship between a specific cooling water temperature region and the map number of the purge advance amount adapted in that region. In step 150, based on the current cooling water temperature THW, a map of the purge advance amount to be used in the current processing cycle is set according to the number setting map.

  In the routine shown in FIG. 8, the purge advance amount CRNKPG is set according to the map set in step 150 (step 152). In each of the maps of the purge advance amount used in the present embodiment, an appropriate purge advance amount CRNKPG is determined in relation to the number of purges as in the map used in the first embodiment. These maps are determined such that the purge advance amount CRNKPG generally increases as the map number decreases, that is, as the corresponding cooling water temperature THW decreases.

  More specifically, the plurality of purge advance amount maps used in the present embodiment indicate that the correction time ΔTPG of the purge time TPG and the change amount of the pre-intake purge time in accordance with the variation of the cooling water temperature THW It is set to show changes corresponding to.

  According to the processing of step 152, as in the case of the second embodiment, the purge advance amount CRNKPG is set to an appropriate value according to the number of purges, and the value CRNKPG is set to the fluctuation of the purge time TPG. It can be changed according to. As a result, also by the system of the present embodiment, the internal combustion engine 10 can always be started smoothly as in the case of the second embodiment.

  In the third embodiment described above, the “advance amount setting means” according to the first aspect of the present invention is realized by the ECU 40 executing the processing of steps 150 and 152. Further, since the ECU 40 stores the map shown in the frame of step 150 and the plurality of maps shown in the frame of step 152, the “rule storage means” in the third invention in steps 150 and 152 By setting the purge advance amount CRNKPG, the “setting means” in the third aspect of the present invention is realized.

  In the third embodiment described above, the ECU 40 executes the processing of step 150 to increase the “advance amount correction means” in the fourth aspect of the invention and the “purge advance amount in the fifth aspect of the invention”. "Correcting means" is realized.

Embodiment 4 FIG.
Next, a fourth embodiment of the present invention will be described with reference to FIG. The system of the present embodiment can be realized by causing the ECU 40 to execute a routine shown in FIG. 9 described later instead of the routine shown in FIG. 5 described above in the system of the first embodiment. The system of the present embodiment is the same as the system of the second embodiment or the third embodiment except that the purge advance amount CRNKPG is calculated by adding the correction angle tA to the value read from a single map. It is the same.

  FIG. 9 is a flowchart of a routine executed by the ECU 40 in the present embodiment. The routine shown in FIG. 9 is the same as the routine shown in FIG. 7 except that steps 142 to 146 are replaced by steps 160 and 164. Hereafter, among the steps shown in FIG. 9, the same steps as those shown in FIG.

  In the routine shown in FIG. 9, after the purge time TPG is corrected in step 140, the temporary purge advance amount CRNKPG corresponding to the current number of purges is set by referring to the map (step 160). . In the present embodiment, the ECU 40 stores only one map in which the purge advance amount CRNKPG is determined in relation to the number of purges. This map is set similarly to the map used in the first embodiment (see FIG. 5). Here, a temporary value of the purge advance amount CRNKPG is set according to the map.

  Next, the correction angle tA is calculated based on the purge time TPG set in the current processing cycle (step 162). Next, the final purge advance amount CRNKPG is calculated by adding the correction angle tA to the provisional purge advance amount CRNKPG set in step 160 (step 164).

  As shown in the frame of step 162, the ECU 40 stores a map in which the correction angle tA is determined in relation to the purge correction time ΔTPG. Specifically, this map is set so that the correction angle tA increases as the correction time ΔTPG increases. For this reason, according to the process of step 164, the purge advance amount CRNKPG is extended as the purge time TPG is extended due to the influence of the coolant temperature THW.

  Thereafter, in step 138, the purge start crank angle CRNKPGS is set, and then the current processing cycle is terminated. According to the above process, the purge start crank angle CRNKPGS can be varied in accordance with the length of the purge time TPG as in the case of the second or third embodiment. For this reason, also with the system of the present embodiment, excellent startability can be given to the internal combustion engine 10 as in the case of the second or third embodiment.

  In the fourth embodiment described above, the “advance amount setting means” according to the first aspect of the present invention is realized by the ECU 40 executing the processing of steps 160 to 164. Further, since the ECU 40 stores the map shown in the frame of step 160 and the map shown in the frame of step 162, the “rule storage means” in the third invention executes the processing of step 164. By doing so, the “setting means” in the third aspect of the present invention is realized.

  Further, in the above-described fourth embodiment, the ECU 40 executes the processing of step 162 to increase the “advance amount correction means” in the fourth invention and the “purge advance amount” in the fifth invention. "Correcting means" is realized.

Embodiment 5. FIG.
[Features of Embodiment 5]
Next, a fifth embodiment of the present invention will be described with reference to FIG. The system of the present embodiment can be realized by causing the ECU 40 to execute a routine shown in FIG. 10 described later instead of the routine shown in FIG. 5 described above in the system of the first embodiment.

  In the above-described second to fourth embodiments, the purge time TPG is corrected based on the coolant temperature THW, and the purge advance amount CRNKPG is corrected so that the purge time TPG can be matched with the corrected purge time TPG. It is said. Incidentally, the purge time TPG for supplying a desired amount of evaporated fuel to each cylinder is not limited to the cooling water temperature THW, but is also affected by, for example, the intake pipe pressure MV during cranking. In other words, if the intake pipe pressure MV during cranking is higher than the planned value (close to atmospheric pressure), the purge gas flow rate per unit time decreases, so the purge time TPG needs to be longer than the standard value. . Therefore, in the system of the present embodiment, correction processing for reflecting the difference in the intake pipe pressure MV during cranking in the purge time TPG is executed, and matching with the purge time TPG corrected in this way can be achieved. As described above, the purge advance amount CRNKPG is corrected as appropriate.

[Specific Processing in Embodiment 5]
FIG. 10 is a flowchart of a routine executed by the ECU 40 in the present embodiment in order to realize the above function. The routine shown in FIG. 10 is the same as the routine shown in FIG. 9 except that step 140 is replaced with step 170 and step 162 is replaced with step 172. Hereinafter, of the steps shown in FIG. 10, the same steps as those shown in FIG. 9 are denoted by the same reference numerals, and the description thereof is omitted or simplified.

  In the routine shown in FIG. 10, after the reference value of the purge time TPG is calculated in step 134, processing for reflecting the influence of the intake pipe pressure MV on the purge time TPG is executed (step 170). In order to execute this process, the ECU 40 stores three types of maps for determining the purge correction time ΔTPG as shown in the frame of step 170.

  The first map defines the correction time ΔTPG in relation to the engine speed NE during cranking. More specifically, this map is set so that the correction time ΔTPG becomes longer as the engine speed NE during cranking is lower. The intake pipe negative pressure MV becomes a value closer to the atmosphere as the engine speed NE is lower. Accordingly, the purge time TPG for supplying a desired amount of evaporated fuel becomes longer as the engine speed NE is lower. According to the first map, the correction time ΔTPG can be appropriately set so as to be compatible with the above phenomenon.

  The second map defines the correction time ΔTPG in relation to the idle speed control opening (ISC opening) during cranking. More specifically, this map is set so that the correction time ΔTPG becomes longer as the ISC opening is larger. The ISC opening is an opening that determines the intake air amount Ga during idling. The larger the value, the greater the intake air amount Ga during cranking. The intake pipe pressure MV tends to become a value closer to the atmospheric pressure as the intake air amount Ga is larger. Therefore, the purge time TPG for supplying the desired amount of evaporated fuel becomes longer as the ISC opening is larger. According to the second map, the correction time ΔTPG can be appropriately set so as to be compatible with the above phenomenon.

  The third map defines the correction time ΔTPG in relation to the battery voltage during cranking. More specifically, this map is set so that the correction time ΔTPG becomes longer as the battery voltage is lower. The engine speed NE at the time of cranking becomes lower as the battery voltage is lower. Therefore, the purge time TPG for supplying the desired amount of evaporated fuel becomes longer as the battery voltage is lower. According to the third map, the correction time ΔTPG can be appropriately set so as to be compatible with the above phenomenon.

  By the way, the third map defines the correction time ΔTPG in relation to the battery voltage, but the battery voltage may be replaced with the magnitude of an electric load such as a light or a brake lamp. That is, the battery voltage decreases as the electrical load increases. For this reason, the third map can be replaced with a map that is set such that the correction time ΔTPG becomes longer as the electrical load increases.

  In step 170, the ECU 40 calculates the correction time ΔTPG based on the engine speed NE during cranking, the ISC opening, and the battery voltage, respectively, and obtains the average value thereof to obtain the final correction time. Set the TPG. According to such processing, the level of the intake pipe pressure MV during cranking can be appropriately reflected in the correction time ΔTPG. Therefore, according to the system of the present embodiment, an appropriate purge time TPG for supplying a desired amount of evaporated fuel to each cylinder can be set with extremely high accuracy.

  According to the routine shown in FIG. 10, after the reference value of the purge advance amount CRNKPG is set in step 160, the correction angle tA to be added to the purge advance amount CRNKPG is set (step 172). In order to execute this process, the ECU 40 stores three types of maps for determining the correction angle tA as shown in the frame of step 172.

  The first map defines the correction angle tA in relation to the engine speed NE during cranking. The second map defines the correction angle tA in relation to the idle speed control opening (ISC opening) during cranking. Further, the third map defines the correction angle tA in relation to the battery voltage during cranking. All of these maps are set so as to show the same tendency as the three maps used in step 170 above. Therefore, according to these maps, the correction angle tA can be made larger as the correction time ΔTPG becomes longer.

  In step 172, the ECU 40 calculates the correction angle tA based on the engine speed NE during cranking, the ISC opening, and the battery voltage, and obtains the average value thereof, thereby obtaining the final correction angle. Set tA. Then, based on the correction angle tA, the processes of steps 164 and 138 are sequentially executed.

  According to the above processing, the purge start crank angle CRNKPGS can be advanced appropriately in accordance with the extension of the purge time TPG, as in the second to fourth embodiments. For this reason, according to the system of the present embodiment, it is possible to reliably end all purges before the end of the intake stroke while appropriately reflecting the influence of the intake pipe pressure MV during cranking on the purge time TPG. it can. As a result, according to the system of the present embodiment, extremely excellent startability can be imparted to the internal combustion engine 10.

  By the way, in the above-described fifth embodiment, in order to reflect the influence of the intake pipe pressure MV on the purge time TPG and the purge advance amount CRNKPG, three elements, that is, the engine speed NE, the ISC opening, and the battery Although the voltage is to be observed, the present invention is not limited to this. That is, these elements do not necessarily have to be handled in combination, and the purge time TPG and the purge advance amount CRNKPG may be set based on any one of the elements.

  In the fifth embodiment described above, the engine speed NE, the ISC opening degree, and the battery voltage are used as characteristic values correlated with the intake pipe pressure MV, respectively. However, the purge time TPG and the purge advance angle are used. The value on which the correction of the quantity CRNKPG is based is not limited to these. That is, the value serving as the basis of correction may be a physical quantity having a correlation with the intake pipe pressure MV, and may be, for example, the intake pipe pressure MV itself.

  In the fifth embodiment described above, the engine speed NE, the ISC opening degree, and the battery voltage correspond to the “intake pipe pressure correlation value” in the sixth invention, and the ECU 40 detects them. Thus, the “correlation value acquisition means” according to the sixth aspect of the present invention is realized. Further, the “correction means” in the sixth invention is realized by the ECU 40 executing the process of step 170, and the “correction means” in the sixth invention is realized by executing the process of step 172. ing.

Embodiment 6 FIG.
[Features of Embodiment 6]
Next, a sixth embodiment of the present invention will be described with reference to FIG. 11 and FIG. The system of the present embodiment is realized by causing the ECU 40 to execute a routine shown in FIG. 11 and a routine shown in FIG. 12 described later instead of the routine shown in FIG. 5 described above in the system of the first embodiment. be able to.

  In the first to fifth embodiments described above, the intake pipe pressure MV at the end of cylinder discrimination, that is, the intake pipe pressure MV at the time when the first purge is started is handled as being almost constant. Yes. However, the intake pipe pressure MV at that time becomes a different value according to the time required until the cylinder discrimination signal is generated after the cranking is started.

  That is, when the internal combustion engine 10 is stopped in a state where the pistons of the # 1 cylinder and the # 4 cylinder are located immediately before reaching the top dead center, the crank angle is changed only slightly after the cranking is started. A cylinder discrimination signal is generated. On the other hand, when the internal combustion engine 10 is stopped in a state where the pistons of the # 1 cylinder and the # 4 cylinder are located immediately after the top dead center is exceeded, the crank angle is 360 ° CA after the cranking is started. The cylinder discrimination signal is not generated until it rotates close.

  The intake pipe pressure MV at the end of cylinder discrimination becomes negative as the operating amount of the internal combustion engine 10 before the cylinder discrimination signal is generated increases. Therefore, the intake pipe pressure MV at the end becomes lower as the time required from the start of cranking to the end time becomes longer.

  If the intake pipe pressure MV at the time when the first purge is started is different, the purge time TPG for supplying the evaporated fuel necessary for the start is also different. Therefore, in the present embodiment, the purge time TPG is corrected based on the time required until the end of the cylinder discrimination, and the purge advance amount CRNKPG is corrected so as to match the correction.

[Specific Processing in Second Embodiment]
FIG. 11 is a flowchart of a routine executed by the ECU 40 to measure the time required until the end of cylinder discrimination. In this routine, first, it is determined whether or not the starter switch 44 is turned on (step 180). As a result, when it is determined that the starter switch 44 is not turned on, the current processing cycle is terminated.

  On the other hand, if it is determined that the starter switch 44 is on, it is then determined whether or not a value of 0 or more is counted in the crank angle counter CCRNK (step 182). The crank angle counter CCRNK is set to 0 when the cylinder discrimination signal indicating that the # 4 cylinder has reached the intake top dead center is generated, and the cylinder indicating the # 1 cylinder has reached the intake top dead center. At the time when the determination signal is generated, a value (positive value) corresponding to 360 ° CA is substituted. After the cranking is started and before those cylinder discrimination signals are issued, the count value of CCRNK is a negative value. For this reason, according to the processing in step 182 described above, it can be substantially determined whether any cylinder discrimination signal is generated after the cranking is started, that is, whether the cylinder discrimination is finished.

  If it is determined in step 182 that CCRNK ≧ 0 is not established, it can be determined that the cylinder discrimination has not been completed yet. In this case, the cylinder discrimination counter TCCRNK is then incremented (step 184). On the other hand, when the establishment of CCRNK ≧ 0 is recognized, the current processing cycle is terminated without incrementing TCCRNK.

  The cylinder discrimination counter TCCRNK is reset by an initial process when the internal combustion engine 10 is started. For this reason, the final value of TCCRNK corresponds to the time required for cylinder discrimination. Hereinafter, for convenience of explanation, TCCRNK is referred to as “cylinder discrimination time”.

  FIG. 12 is a flowchart of a routine executed by the ECU 40 to determine the purge time TPG and the purge advance amount CRNKPG. The routine shown in FIG. 12 is the same as the routine shown in FIG. 9 except that step 140 is replaced with step 190 and step 162 is replaced with step 192. Hereinafter, of the steps shown in FIG. 12, the same steps as those shown in FIG. 9 are denoted by the same reference numerals, and the description thereof is omitted or simplified.

  In the routine shown in FIG. 12, after the reference value of the purge time TPG is calculated in step 134, processing for correcting the purge time TPG is executed based on the cylinder discrimination time TCCRNK (step 190). In order to execute this processing, the ECU 40 stores a map that defines the purge correction time ΔTPG in relation to the cylinder discrimination time TCCRNK, as shown in the frame of step 190. Here, first, the correction time ΔTPG corresponding to TCCRNK measured by the routine shown in FIG. 11 is set according to the map. Next, the final purge time TPG is calculated by adding the correction time ΔTPG to the purge time TPG set in step 134.

  The above map is set so that the correction time ΔTPG becomes longer as the cylinder discrimination time TCCRNK is shorter. The intake pipe negative pressure MV at the start of the first purge becomes a value closer to the atmosphere as the cylinder discrimination time TCCRNK is shorter. Accordingly, the purge time TPG for supplying the desired amount of evaporated fuel becomes longer as the cylinder discrimination time TCCRNK is shorter. According to the above map, the correction time ΔTPG can be appropriately set so as to match the phenomenon.

  According to the routine shown in FIG. 12, after the reference value of the purge advance amount CRNKPG is set in step 160, the correction angle tA to be added to the purge advance amount CRNKPG is set (step 192). In order to execute this process, the ECU 40 stores a map in which the correction angle tA is determined in relation to the cylinder discrimination time TCCRNK, as shown in the frame of step 192.

  The map of the correction angle tA is set so as to show the same tendency as the map of the correction time ΔTPG used in step 190, that is, the shorter the cylinder discrimination time TCCRNK, the larger tA becomes. Therefore, according to this map, the correction angle tA can be made larger as the correction time ΔTPG becomes longer.

  The ECU 40 sequentially executes the processing of steps 164 and 138 based on the correction angle tA set in step 192. According to the above processing, the purge start crank angle CRNKPGS can be advanced appropriately in accordance with the extension of the purge time TPG, as in the second to fifth embodiments. For this reason, according to the system of the present embodiment, all the purges are reliably ended before the end of the intake stroke while appropriately reflecting the influence of the intake pipe pressure MV at the end of cylinder discrimination on the purge time TPG. be able to. As a result, according to the system of the present embodiment, extremely excellent startability can be imparted to the internal combustion engine 10.

  In the sixth embodiment described above, the crank angle sensor 46 corresponds to the “cylinder discrimination means” in the tenth aspect of the invention, and the ECU 40 executes the routine shown in FIG. The “cylinder discrimination time measuring means” in the present invention is realized.

It is a figure for demonstrating the structure of Embodiment 1 of this invention. It is a timing chart for demonstrating operation | movement of the 1st comparative example contrasted with operation | movement of Embodiment 1 of this invention. It is a timing chart for demonstrating operation | movement of the 2nd comparative example contrasted with operation | movement of Embodiment 1 of this invention. 3 is a timing chart for explaining the operation of the first embodiment of the present invention. It is a flowchart of the main routine performed in Embodiment 1 of the present invention. It is a flowchart of a series of processes performed in step 106 shown in FIG. It is a flowchart of the routine performed in Embodiment 2 of this invention. It is a flowchart of the routine performed in Embodiment 3 of the present invention. It is a flowchart of the routine performed in Embodiment 4 of this invention. It is a flowchart of the routine performed in Embodiment 5 of this invention. It is a flowchart of the routine performed in order to measure cylinder discrimination | determination time in Embodiment 6 of this invention. It is a flowchart of the main routine performed in Embodiment 6 of this invention.

Explanation of symbols

10 Internal combustion engine 16 Intake manifold 24 Purge passage 26 D-VSV
28 Canister 32 Air hole 40 ECU (Electronic Control Unit)
42 Ignition switch (IG switch)
44 Starter switch 46 Crank angle sensor 48 Water temperature sensor
MV intake pipe pressure
THW Cooling water temperature
NE engine speed
CCRNK Crank angle counter
CRNKPG Purge advance amount
CRNKPGS Purge start crank angle
TCCRNK Cylinder discrimination time

Claims (10)

An evaporative fuel processing apparatus for supplying evaporative fuel to an internal combustion engine having a plurality of cylinders,
A canister that stores evaporative fuel;
A purge passage communicating the canister to the intake port of each cylinder;
A purge control valve provided for each cylinder to control the conduction state between the intake port of each cylinder and the canister;
Control valve drive means for opening the purge control valves of the individual cylinders for a predetermined purge time in synchronization with the crank angle after the internal combustion engine is started,
A purge start angle setting means for setting a position advanced by a purge advance amount from a crank angle at which an intake stroke is started in each cylinder as a purge start crank angle corresponding to each intake stroke;
The purge advance amount corresponding to the intake stroke immediately after the first explosion executed following the intake stroke at the time of the first explosion executed simultaneously with the first explosion is set to the intake stroke before the first explosion executed before the intake stroke at the time of the first explosion. An advance amount setting means for setting a larger value than the purge advance amount corresponding to
An evaporative fuel processing apparatus comprising:   The advance angle setting means sets the purge advance amount corresponding to the intake stroke at the time of initial explosion larger than the purge advance amount corresponding to the intake stroke before the initial explosion. The evaporative fuel processing apparatus of Claim 1. The advance amount setting means includes:
Purge number counting means for counting the number of purges performed after the start of the internal combustion engine, with the control valve being opened once for the purge time in one cylinder;
Rule storage means for storing a rule that defines the relationship between the number of purges and the purge advance amount;
Setting means for setting purging advance amount in each cylinder according to the rule based on the number of purges;
The evaporative fuel processing apparatus of Claim 1 or 2 characterized by the above-mentioned. A purge time correcting means for correcting the purge time based on the state of the internal combustion engine;
The advance angle setting means includes an advance amount correction means for correcting the purge advance amount so as to be adapted to expansion and contraction of the purge time. Evaporative fuel processing device. A cooling water temperature detecting means for detecting the cooling water temperature of the internal combustion engine;
The purge time correction means includes correction means for increasing the purge time as the cooling water temperature is lower,
5. The evaporative fuel processing apparatus according to claim 4, wherein the advance angle correction means includes a correction means for increasing the purge advance angle as the coolant temperature decreases. Correlation value acquisition means for acquiring an intake pipe pressure correlation value having a correlation with the intake pipe pressure during cranking,
The purge time correction means includes correction means for increasing the purge time as the intake pipe pressure is closer to atmospheric pressure based on the intake pipe pressure correlation value,
6. The advance angle correction means includes correction means for increasing the purge advance amount as the intake pipe pressure is closer to atmospheric pressure based on the intake pipe pressure correlation value. The evaporative fuel processing apparatus of description. The intake pipe pressure correlation value includes the engine speed,
The purge time correction means corrects the purge time longer as the engine speed during cranking is lower,
7. The evaporative fuel processing apparatus according to claim 6, wherein the advance angle correction means corrects the purge advance angle larger as the engine speed during cranking is lower. The intake pipe pressure correlation value includes an idle speed control opening,
The purge time correction means corrects the purge time longer as the idle speed control opening during cranking is larger,
8. The evaporative fuel processing apparatus according to claim 6, wherein the advance angle correction means corrects the purge advance angle as the idle speed control opening during cranking increases. The intake pipe pressure correlation value includes a battery voltage;
The purge time correction means corrects the purge time longer as the battery voltage during cranking is lower,
9. The evaporative fuel processing apparatus according to claim 6, wherein the advance angle correction means corrects the purge advance amount larger as the battery voltage during cranking is lower. Cylinder discrimination means for generating a cylinder discrimination signal when the absolute position of the crank angle is determined after the internal combustion engine is started,
A cylinder discrimination time measuring means for measuring a cylinder discrimination time required until the cylinder discrimination signal is issued after the internal combustion engine is started,
The intake pipe pressure correlation value includes the cylinder discrimination time,
The purge time correction means corrects the purge time longer as the cylinder discrimination time is shorter,
10. The evaporative fuel processing apparatus according to claim 6, wherein the advance angle correction means corrects the purge advance angle larger as the cylinder discrimination time is shorter.

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