JP2681567B2 - Two-cycle engine starting injection amount control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a start-up injection amount control device for a two-cycle engine, and more particularly, it optimizes the fuel injection amount at the start of the engine to facilitate start-up and improve startability. The present invention relates to a fuel injection amount control device for starting a cycle engine.

[0002]

2. Description of the Related Art In a two-cycle engine used for a motorcycle, a snowmobile, etc., an electronically controlled fuel injection system using a fuel injection valve is being adopted instead of a conventional fuel supply system using a carburetor (Japanese Patent Laid-Open No. 63-63). No. 255554, etc.), for example, a fuel injection valve is provided in the intake manifold portion for each cylinder so that all cylinders are simultaneously injected.

By the way, as a two-cycle engine, the crank chamber side is used as a kind of reciprocating compressor, and the air-fuel mixture sucked into the crank chamber through the intake holes is compressed by the reciprocating motion of the piston, and then compressed into the crank chamber. 2. Description of the Related Art A so-called crank chamber compression type two-cycle engine is widely known which is configured to flow air into a cylinder to perform scavenging.

In such a crank chamber compression type two-cycle engine, the air-fuel mixture is made to flow into the cylinder through the crank chamber, and the distance from the fuel supply section to the cylinder is long. The fuel is injected to prevent the air-fuel ratio from becoming lean and the starting performance is improved. For example, correction control of the fuel injection amount at the start based on the engine temperature when the engine temperature is lower than a predetermined temperature is performed. Based on the basic fuel injection amount and various correction coefficients, the fuel injection amount at the start ( Fuel injection pulse width)
Is calculated, and the fuel injection valve is controlled to inject fuel based on the calculated fuel injection amount.

[0005]

However, in the conventional fuel injection control structure at the time of starting as described above, the condition of the engine and the state of the engine are changed from the relationship between the amount of gas remaining in the crank chamber and the correction at the time of starting. There is a problem that appropriate fuel injection control cannot be performed depending on the environment or the like. That is, in the above-mentioned crank chamber compression type two-cycle engine, the crank chamber, the scavenging port and the exhaust port communicate with each other when the engine is stopped, and the gas remaining in the crank chamber communicates with the crank chamber, the scavenging port and the exhaust port. Evaporates to the outside of the engine.

For example, when the engine is stopped with the engine running and left as it is, as shown in FIG. 7, the residual gas amount in the crank chamber gradually decreases as the time elapses, and finally the crank chamber becomes dry. Become. Even after storing the vehicle for a long time in the summer, the crank chamber remains dry as described above.

On the other hand, when the engine is stopped after idling and left as it is, as shown in FIG. 7, the residual gas amount in the crank chamber gradually decreases as the time elapses, but the engine is stopped after running the vehicle. The amount of residual gas in the crank chamber is large compared to when left unattended, and even if the engine is stopped after the vehicle has been running and left unattended for a given amount of time, the crank chamber will be dry, but the engine will be stopped after idling. When left unattended, there is still a large amount of residual gas in the crank chamber.

Here, as shown in FIG. 7, when the engine is stopped and left as it is after the vehicle has run, even if the crank chamber is dry, if the engine temperature is in a region below a predetermined temperature, the engine temperature Since the fuel injection amount at the time of starting is corrected and controlled based on the above, the engine can be started satisfactorily. Further, when the engine is stopped and left after running the vehicle, and when the engine is stopped and left after idling and the residual gas is large, the engine can be started well. However, when the engine is stopped and left as it is after running the vehicle, when the crank chamber is dry, and the engine is not cold and the engine temperature is in a region other than the region below the predetermined temperature, Since the correction control of the fuel injection amount at the time of starting is not performed as described above, engine start failure occurs.

In order to avoid the above engine starting failure, when the engine temperature at the start of correction of the fuel injection amount at the time of starting is raised, a large amount of residual gas is generated as when the engine is stopped after idling and left standing. At some time, the correction control of the fuel injection amount at the time of starting is performed, and conversely, the air-fuel ratio is made rich, and the engine start failure occurs. Therefore, in view of the conventional problems as described above, the present invention monitors the temperature of the engine and the predetermined number of operations accompanying the start of the engine when the incomplete explosion determination is made, and when these satisfy the predetermined conditions. The object of the present invention is to favorably start the engine by adopting a configuration in which a predetermined amount of fuel is interrupted and injected in the next engine starting operation.

[0010]

Therefore, a start-up injection amount control device for a two-cycle engine according to the present invention comprises a fuel injection valve, an engine temperature detecting means for detecting an engine temperature, and the engine temperature detecting means. A fuel injection amount correction means at start for correcting and controlling the fuel injection amount at start based on the engine temperature when the detected engine temperature is in a region lower than a predetermined temperature, and fuel based on the corrected fuel injection amount at start. A fuel injection control means for controlling the fuel injection valve to inject the fuel, a start-up injection amount control device for a two-cycle engine, and a complete explosion determination means for the engine,
A predetermined engine operation number detection means for detecting a predetermined operation number of the engine upon starting, and a detection signal output from the predetermined engine operation number detection means when the complete explosion determination means makes a non-complete explosion determination when the engine is started. A predetermined engine operation number determination means for determining whether or not the predetermined engine operation number exceeds a set number based on the above, and a temperature at which the engine temperature detected by the engine temperature detection means corrects and controls the fuel injection amount at the start. A temperature range determination means for determining whether or not the temperature range is a predetermined temperature range higher than the range, and the operation frequency determination means determines that the temperature range is within the predetermined temperature range and the number of operations exceeds the set number of times. If it is determined that the fuel injection valve is interrupted, a predetermined amount of fuel is interrupted to be injected during the next starting operation. Configured to include a control means, the.

[0011]

In such a structure, it is detected that the engine temperature is outside the correction range of the fuel injection amount at the time of starting the engine, and the predetermined number of operation of the engine accompanying the start when the engine is not completed is set to the set number of times. Therefore, when it is estimated that the crank chamber is in a dry state, a predetermined amount of fuel is interrupted and injected at the time of the next starting operation, so that the engine can be started satisfactorily.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 2 is a control system diagram of a two-cycle gasoline engine 1 adopting a fuel injection method. The engine 1 is a crank chamber compression type two-cycle gasoline engine, and is configured to flow scavenging air-fuel mixture compressed in the crank chamber 2 into the cylinder 3.

That is, the wall surface of the cylinder 3 is provided with an intake hole 4, a scavenging hole 5, and an exhaust hole 6, and the low pressure generated in the lower part of the piston 7 in the compression stroke causes the intake hole 4 in the crank chamber 2. When the piston passes over the exhaust hole at the end of the work stroke, the combustion gas in the cylinder is discharged through the exhaust hole 6, and when the piston 7 goes down, the scavenging hole 5 and the crank chamber 2 are discharged. And the crank chamber 2
The air-fuel mixture compressed in 2 flows into the cylinder 3 to scavenge the exhaust gas.

In the intake passage 8 communicating with the intake hole 4,
An electromagnetic fuel injection valve 9 is provided, and a fuel-air mixture is formed by the fuel injected and supplied from the fuel injection valve 9, and flows into the crank chamber 2 from the intake hole 4. The fuel injection valve 9 is opened by a valve opening drive signal sent from a control unit 10 with a built-in microcomputer, which includes a central processing unit, an input / output processing unit, a memory and the like, and injects fuel adjusted to a predetermined pressure. The fuel injection amount can be controlled by the valve opening time of the fuel injection valve 9.

The control unit 10 includes an engine rotation speed signal from a rotation sensor 11 built in a distributor (not shown) and an intake passage 8 upstream of the fuel injection valve.
A water temperature sensor 13 as a temperature detecting means for detecting an intake air flow rate signal from an air flow meter 12 installed in the engine and a cooling water temperature as an engine temperature (a crankcase temperature may be detected as an engine temperature). Etc. are input, the input data from these sensors is arithmetically processed by the built-in microcomputer to determine the fuel injection amount (injection time) and injection timing, and the valve opening drive corresponding to this is determined. The signal is output to the fuel injection valve 9. A battery voltage is applied to the control unit 10 via the ignition switch 15.

Next, the manner of interrupt fuel injection control by the control unit 10 will be described with reference to the flow charts of FIGS. The functions of the complete explosion determination means of the engine, the engine predetermined operation number determination means, the temperature region determination means, and the interrupt injection control means according to the present invention are:
As shown in the flow charts of FIGS. 3 to 5, the control unit 10 is provided as software.

In the flowchart of FIG. 3, in step 1 (abbreviated as S1 in the figure; hereinafter the same), the water temperature detected by the water temperature sensor 13 is higher than a predetermined temperature range in which the fuel injection amount at the time of start is corrected and controlled. It is determined whether or not the temperature range of 1), that is, the temperature range in which interruption is permitted. That is, in step 1, the actual water temperature TWN is compared with the low-side interrupt permission temperature RIRTWL, and TWN ≧ RIRT
If it is WL, proceed to step 2 and TWN <RIRTW
If L, go to step 3. In step 2, the actual water temperature TWN is compared with the high-side interrupt permission temperature RIRTWH, and if TWN <RIRTWH, the process proceeds to step 4, and if TWN ≧ RIRTWH, the process proceeds to step 3. The low-side interrupt permission temperature RIRTWL is the fuel injection amount correction start temperature (see FIG. 7), and the high-side interrupt permission temperature RI
In FIG. 7, the RTWH is the engine 1 after traveling the vehicle.
The temperature is the temperature at which the crank chamber begins to become dry when it is stopped and left to stand, and is determined in advance by experiments or the like.

In step 4, the complete explosion of the engine 1 is determined. This complete explosion determination is executed based on the complete explosion determination program shown in the flowchart of FIG. In this flowchart, in step 21, it is determined whether an engine stall (stalling) has occurred. If an engine stall has occurred, the routine proceeds to step 22, where it is determined that the explosion is incomplete and the program ends. If no engine stall has occurred, the routine proceeds to step 23, where the actual engine speed N and the complete explosion determination engine speed REKAN (see FIG. 6) are compared, and if N ≧ REKAN, then step 2
4. If N <REKAN, go to step 25. In step 24, the time T measured by the complete explosion determination timer
MKAN (see FIG. 6) is compared with the complete explosion determination time RKANHN, and if TMKAN ≧ RKANHN, the routine proceeds to step 26, where it is determined that complete explosion has occurred, and this program is terminated as it is. If TMKAN <RKANHN, the process returns to step 21. In step 25, the measurement time TMKAN measured by the complete explosion determination timer is set to 0 and step 21
Return to

Returning to the flowchart of FIG. 3, step 4
If it is determined that the explosion is not completed, the process proceeds to step 5, and if it is determined that the explosion is complete, the process proceeds to step 3. If the temperature is not within the temperature range in which the interrupt is permitted, or if the complete explosion occurs even in the temperature range in which the interrupt is permitted, in steps 3, flags F1 and F2, which will be described later, are set.
Are both set to 0, a count value RECNT (see FIG. 6) by a recoil counter described later is set to 0, and the process returns.

In step 5, the flag F2 is 0,
Whether it is set to 1 or not is determined. If it is set to 1, it returns, and if it is set to 0,
Go to step 6. In step 6, the flag F1 is 0,
Whether it is set to 1 or not is determined. If it is set to 1, the process proceeds to step 7, and if it is set to 0, the process proceeds to step 8. In step 8, the actual engine rotation speed N and the recoil determination rotation speed RRE
C (see FIG. 6) and if N <REREC,
Proceed to step 9, and if N ≧ REREC, proceed to step 10. In step 10, the flag F1 is set to 1, the process proceeds to step 11, the current count value RECNT obtained by the recoil counter is incremented by 1, and the process proceeds to step 9.

On the other hand, in step 7, it is judged whether or not the engine is stalled. If the engine is not stalled, the processing directly proceeds to step 9, and if it is stalled, the processing proceeds to step 12 and the flag F1 is set to 0. To go to step 9. In step 9, the count value RECNT by the recoil number counter is compared with the recoil number IRQINJ for which interrupt injection is permitted, and RECNT <IRQI
If it is NJ, that is, if the actual number of recoils is less than the number of interrupt injection permission recoils, the routine returns and the RECN
If T ≧ IRQINJ, that is, if the actual number of recoils is equal to or greater than the number of interrupt injection permission recoils, the process proceeds to step 13.

In step 13, the cooling water temperature TWN detected by the water temperature sensor 13 is searched for a predetermined interrupt injection amount INJIRQ, and the process proceeds to step 14 to set the flag F2 to 1. To do. The interrupt injection amount INJIRQ is used by the fuel injection amount setting program shown in the flowchart of FIG.

That is, in the flowchart of FIG. 5, in step 31, the intake air flow rate Q and the engine rotation speed N are set.
And the basic fuel injection amount Tp (= K × Q / N; K is a constant)
Is calculated. In the next step 32, the cooling water temperature TWN
Various correction factors COEF are set based on the operating state mainly.

In step 33, the voltage correction amount Ts is set in order to correct the change in the effective valve opening time of the fuel injection valve 9 due to the battery voltage. In step 34, based on the basic fuel injection amount Tp, various correction coefficients COEF, and the voltage correction amount Ts, the fuel injection amount Ti (= Tp × COE during normal operation)
F + Ts) is calculated.

By outputting a drive signal corresponding to the fuel injection amount Ti to the fuel injection valve 9 at a predetermined timing, fuel supply control during normal operation is executed. On the other hand, when the engine 1 is started (when the starter motor is ON), the starting fuel injection amount POUT for injecting a larger amount of fuel than the fuel injection amount Ti during the normal operation is separately set.

That is, when the ON state of the starter switch (not shown) is judged in step 35, the routine proceeds to step 36, where the starting fuel injection amount POUT is set. The starting fuel injection amount POUT is set by correcting the basic fuel injection amount based on the water temperature TWN with the engine speed and the elapsed time from the start. In the next step 37, the interrupt injection amount IN
It is determined whether or not JIRQ is 0. If it is 0, the routine proceeds to step 38, where the starting fuel injection amount POUT set at the time of the first injection is set as it is as the actual injection amount. If the interrupt injection amount INJIRQ is set in the program shown in the flowchart of FIG. 3 and the interrupt injection amount INJIRQ is not 0, the routine proceeds to step 39, where the starting fuel injection amount preset at the time of the first injection. The interrupt injection amount INJIRQ is added to POUT and set as the actual injection amount, and the routine proceeds to step 40, where the interrupt injection amount INJIRQ set in the program shown in the flowchart of FIG. 3 is set to zero.

As is clear from the above description of each flow chart, the next starting operation when it is determined that the engine cooling water temperature is in the interrupt permission temperature region and the number of recoils exceeds the interrupt permission recoil number At the time of the first injection, the fuel of the injection amount POUT, which is the preset starting fuel injection amount POUT plus the interrupt injection amount INJIRQ, is injected once (see the hatched portion of the fuel injection pulse in FIG. 6). . That is, it is detected that the engine water temperature is outside the correction range of the fuel injection amount at the time of starting the engine, and the predetermined number of operation of the engine accompanying the start when the engine is not completed explosion reaches the set number of times. When it is estimated that the vehicle is in a dry state, a predetermined amount of fuel is interrupted and injected during the next start operation.

Therefore, when the engine is stopped and left as it is after running the vehicle, the crank chamber is dry, the engine is not cold, and the engine temperature is less than the predetermined temperature range. In the case of, the predetermined amount of fuel is interrupted and injected, so that the engine can be started satisfactorily. Further, the engine can be started well even after the vehicle is stored in the summer for a long time.

If there is residual gas in the crank chamber,
Since the fuel is not injected by interruption, the enrichment of the air-fuel ratio can be prevented and the engine start failure due to the enrichment of the air-fuel ratio can be avoided. In the above embodiment, the fuel interrupt injection is performed only once, and the next interrupt injection can be performed only after the engine key is turned off once. However, the fuel interrupt injection is performed once. 2 if the engine still does not start after going
The fuel may be interrupted for the second time.
At this time, the interrupt injection amount may be changed between the first and second times.

Further, in the above embodiment, the recoil operation is adopted as the predetermined operation of the engine upon starting and the recoil frequency is detected. However, the cranking frequency is adopted and the cranking frequency is detected. It may be configured. The structure of the above embodiment does not represent a structural limitation of the present invention, and the present invention can be freely modified within the scope described in the claims.

[0031]

As described above, according to the starting injection amount control device for a two-cycle engine of the present invention, the engine temperature and the predetermined number of operations associated with the starting of the engine when it is determined that the engine has not completed explosion The engine is configured to inject a predetermined amount of fuel in an interrupted manner in the next engine starting operation when these meet predetermined conditions. The inside of the room is dry, the engine is not cold, and the engine can be started well when the engine temperature is outside the start correction range. Therefore, it is very useful that the startability of the engine can be improved at all times.

[Brief description of the drawings]

FIG. 1 is a block diagram showing the configuration of the present invention.

FIG. 2 is a system diagram showing an embodiment of the present invention.

FIG. 3 is a flowchart showing a state of fuel injection control in the embodiment.

FIG. 4 is a flowchart showing a state of fuel injection control in the embodiment.

FIG. 5 is a flowchart showing a state of fuel injection control in the embodiment.

FIG. 6 is a time chart showing a state of fuel injection control in the embodiment.

FIG. 7 is a time chart for explaining problems with conventional control.

[Explanation of symbols]

 1 Engine 9 Fuel Injection Valve 10 Control Unit 13 Water Temperature Sensor

Claims (1)

(57) [Claims] 1. An engine temperature detecting means for detecting an engine temperature, comprising a fuel injection valve; and an engine temperature detected by the engine temperature detecting means at the time of starting based on the engine temperature in a region below a predetermined temperature. A fuel injection amount correction means at startup for correcting and controlling the fuel injection quantity, and a fuel injection control means for controlling the fuel injection valve to inject fuel on the basis of the corrected fuel injection quantity at startup.
In a start-up injection amount control device for a cycle engine, a complete explosion determination means for the engine, a predetermined engine operation number detection means for detecting a predetermined operation number of the engine accompanying the start, and an uncompleted explosion by the complete explosion determination means at the time of starting the engine. A predetermined engine operation number determination means for determining whether or not the predetermined engine operation number exceeds a set number based on a detection signal output from the predetermined engine operation number detection means when the determination is made, and the engine temperature detection means. Temperature range determining means for determining whether the engine temperature detected by the temperature range is higher than a temperature range for correcting and controlling the fuel injection amount at the time of starting, and a predetermined temperature range by the temperature range determining means. If it is determined that the number of times of operation exceeds the set number of times by the operation number determination means, the next starting operation is performed. Interrupt injection control means and the comprise startup injection amount control apparatus of a two-stroke engine, characterized in that it is configured for controlling the fuel injection valve in order to interrupt the injection of the predetermined amount of fuel to.