JPS61129438A - Starting system for engine - Google Patents

Abstract

PURPOSE:To eliminate the engine disorder immediately after the complete combustion by gradually reducing the fuel injection amount to the value for the state after perfect combustion after the lapse of a prescribed transient time from the time-point of transfer of the engine from cranking operation to the perfect combustion. CONSTITUTION:When a judging means 7 judges from the engine revolution speed detected by a revolution-speed detecting means 6 that an engine shifts from cranking operation to the complete combustion operation, an opening-degree instruction means 8 outputs the opening and closing instruction for the state after the complete combustion in substitution for the opening and closing instruction for cranking state. Therefor, a valve opening-degree adjusting means 5 for shifting the closing position of a throttle valve 2 is operated by a prescribed amount in the direction of opening. Further, the injection instruction for cranking time outputted from a fuel injection-amount instruction means 9 after the lapse of a prescribed transient time from the above-described judging time-point is shifted to the injection instruction for the state after the complete combustion. Therefore, the fuel injection amount by a fuel injection means 4 is gradually reduced to the value for the state after the complete combustion during the above- described transient time.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application J] The present invention relates to a starting system mainly applied to an automobile engine.

[Prior Art] A gasoline engine is generally equipped with a choke system as a starting system because it is safe to use a particularly rich air-fuel mixture when starting the engine. However, the choke system requires a choke valve to be interposed within the carburetor, as well as a mechanical structure such as a link mechanism for opening and closing this valve manually or automatically. As a result, the structure of the fuel supply system is inevitably complicated, which is an obstacle to enclosing the structure of the engine as a whole.

In order to deal with such inconveniences, the first 11 techniques for starting/systems were developed in Japanese Unexamined Patent Publication No. 58-237, which was filed earlier.
There is one as shown in Japanese Patent No. 632. That is,
This starting system includes a fuel injection means that supplies an amount of fuel corresponding to an injection command signal, and a valve opening fJ4 that moves the closing position of the throttle valve according to the opening/closing command signal.
a rotation speed detection means for detecting the rotation speed of the engine; and a determination means for determining whether the engine is cranking or after completion of a complete explosion using the rotation speed detection means;
When it is determined that the engine is in cranking operation, an opening/closing command signal for cranking is output, and when it is determined that the engine has completed combustion, it is set to the open side rather than during cranking. opening command means for outputting an opening/closing command signal; and when the determining means determines that the engine is in cranking operation, outputs an injection command signal for cranking, and determines that the engine has completely exploded. and fuel injection amount command means for outputting an injection command signal for use after complete explosion, which is set to a lower fuel supply amount value than during cranking.

However, this one is Kunono1-/゛guz1! After IIg transitions to rolling complete explosion operation, that is, immediately after determining complete explosion, the opening/closing command signal given to the valve opening command means is switched from one for cranking to one for after complete explosion. , the closed position of the throttle valve is shifted from a low opening for starting to a relatively high opening corresponding to, for example, a first idle speed. Immediately after the complete explosion determination, the injection command signal given to the fuel injection means is changed from a relatively large value for cranking to a relatively small value for after complete explosion. Therefore, the amount of fuel protruding from the fuel injection means is reduced immediately after complete explosion.

Therefore, with this type of engine, immediately after the engine shifts from cranking operation to full explosion operation, the fuel increase value decreases at the same time as the throttle valve opens.
At that point, the air-fuel ratio suddenly changes to the lean side, which may cause the engine to sluggish or stall.

``Problems to be Solved by the Invention'' This invention solves the problem when the air-fuel ratio suddenly shifts to the lean side immediately after a complete explosion is determined.
The aim is to reliably eliminate the problem that a single movement can easily lead to engine malfunction or stalling.

[Means for Solving the Problems] In order to achieve the above objects, the present invention provides a fuel injection system that supplies an amount of fuel corresponding to an injection command signal to an intake system, as shown in FIG. means (4), valve opening adjustment means (5) for moving the closing position of the throttle valve (2) in accordance with the opening/closing command signal, and rotation speed detection means (6) for detecting the rotation speed of the engine. , this rotation speed detection means (6)
A determination means (7) for determining whether the engine is cranking or after completion of a complete explosion based on the engine rotational speed detected by the engine; If it is determined that the transition has occurred, the state is switched from the opening/closing command signal output state for cranking to the opening/closing command signal output state for after complete explosion, and the valve opening adjustment means (5) is moved 15r' in the direction of the closing force. 5Id, fI
Motion! Open 1a TLR command 1st stage (8) and when it is determined by the determination means (7) that the engine has transitioned from cranking operation to complete explosion operation, the injection command signal output state for cranking is changed to complete combustion. Fuel injection amount command means (9) that transitions to an injection command signal output state for post-detonation after a transition period and gradually reduces the fuel injection amount by the fuel injection means (4) to the amount for post-detonation during the transition period; It is characterized by having the following features.

[Function] According to such a configuration, during cranking, the opening/closing command signal for cranking, which is set to a relatively closed side, is sent from the opening command means (8) to the valve opening degree tA adjusting means (5). At the same time, an injection command signal for cranking set to a relatively large value 1 is output from the fuel injection amount command means (9) to the fuel injection means (4). To.

When the engine shifts to full blast operation, at that point, first,
The signal from the opening command means (8) is switched to the opening/closing command signal for use after complete explosion, which is set to a relatively open side, and the valve opening adjustment means (5) is activated to close the throttle valve (2). The position is moved in the opening direction as required. and,
During the transition period from when the complete explosion is reached until the required time elapses, the signal from the fuel injection command means (9) changes from a relatively large value for cranking to a relatively small value. The amount of auxiliary fuel supplied to the intake system by the fuel injection means (4) is gradually changed to the one for after complete explosion after an intermediate stage, and the amount of auxiliary fuel supplied to the intake system by the fuel injection means (4) is gradually reduced. Therefore, the amount of fuel to be replenished does not decrease all at once when the closed position of the throttle valve (2) is shifted to the open direction. Therefore, the phenomenon in which the air-fuel ratio suddenly becomes lean immediately after a complete explosion is determined is reliably eliminated.

[Embodiment] An embodiment of the present invention will be described below with reference to FIGS. 2 to 7.

FIG. 2 is an explanatory diagram of an engine starting system according to the present invention, in which 1 is a carburetor of an automobile engine, 2 is a throttle valve of this carburetor l, 3 is a float chamber, and 4 is an injection command signal. A fuel injection means 5 supplies an amount of fuel corresponding to a into a carburetor l forming a part of the intake system, and a valve opening m! 5 moves the closing position of the throttle valve 2 in response to an opening/closing command signal. ! Means 6 is a rotation speed detection means for detecting the rotation speed of the engine. , and 10 is a microcomputer system that plays the roles of determination means 7, opening degree command means 8, and fuel injection command means 9.

The fuel injection means 4 has an inlet 12 having a check valve 11 connected to the float chamber 3 via an in-left passage 13, and an outlet 14 connected to the carburetor via an out-left passage 16 having a check valve 15. an electromagnetic fuel replenishment pump (SAP) 17 opened to the intake passage 1a of No. 1; a driver 18 that drives the refuel pump 17 at a period corresponding to an injection command signal a supplied from the microcomputer system IO; It is equipped with the following. Refueling pump 17
The piston 22 is housed in a cylinder 21 forming a pump chamber 19, and the piston 22 is moved forward and backward by the biasing force of a spring 23 and the electromagnetic and suction force of a solenoid 24 to operate the pump a billion. It is something.

Further, the driver 18 applies a pulse voltage to the solenoid 24 to move the piston 22 of the refueling pump 17 forward or backward, and by changing the pulse period of the audible voltage, the refueling pump 17 The amount of fuel discharged can be adjusted.

That is, each time one pulse of drive voltage is applied to the solenoid 24 of the refueling pump 17 to cause the piston 22 to reciprocate once, a constant voltage is applied from the refueling pump 17! &(
For example, 0.04 CC) of fuel is discharged. Therefore, if the pulse period FH2 is increased, the pulse interval becomes longer and the amount of fuel discharged per unit time is decreased, and conversely, if the pulse period F)12 is decreased.

The pulse interval is shortened, and the amount of fuel discharged per unit is increased.

On the other hand, the valve opening adjustment means 5 includes an actuator 25 that engages a rotary arm 2b integrally protruding from the support shaft 2a of the throttle valve 2, and an actuator 25 that engages the rotary arm 2b that is recessed. DC to move the closed position of throttle valve 2
It comprises a motor 26 and a driver 27 that applies a DC voltage to the DC motor 26 in a pulse manner to operate the DC motor 26 by an amount corresponding to the opening/closing command signal.

To be more specific, the actuator 25 is in the shape of a limp nut.
The feed screw portion 26 is provided on the output shaft 26a of the DC motor 26 in a state where rotation is prohibited by a guide member (not shown).
b, and the rotating arm 2b of the throttle valve 2 can be locked at its tip. Note that 2c is a spring that urges the throttle valve 2 in the closing direction, and 2d is a wire that opens the throttle valve 2 in response to depression of an accelerator pedal (not shown).

Further, the microcomputer system 10 has a central y4
Computing device 28, memory 29, and interface 3
1.32. Then, the signal C from the one rotation speed detection means 6 and the signal d from the water temperature sensor 33 are input to the interface 31, and the valve opening degree y! is input from the interface 32! 4
The signals a and b are output to the fuel injection means 4 and the fuel injection means 4, respectively.

The rotational speed detection means 6 is for detecting the rotational speed of the engine, and uses, for example, an ignition pulse. The water temperature sensor 33 is for detecting the engine cooling water temperature, and includes, for example, a thermistor that converts the water temperature into an analog electrical signal, and the output of this thermistor. It % A/Di to convert to No. 8
Converter (not shown).

And, the microcomputer system IO has the following:
A program as schematically shown in FIGS. 3a and 3b is built-in. First, in step 51 shown in FIG. 3a, the engine rotation @ detected by the concave plate detection means 6
N and the water temperature T detected by the water temperature sensor 33 are input.Next, at stay 152, it is determined whether the engine is running or not based on the engine speed N, and the engine is stopped. If it is determined that the engine is not stopped, the process proceeds to step 61, and if it is determined that the engine is not stopped, the process proceeds to step 53. In step 53, the engine rotation speed N is selected in advance according to the water temperature and is Explosion judgment value TSTRT (for example, 800 to 44
0 rp■) or more. As a result, if the engine speed N is not equal to or higher than the redundant value TSTRT for complete explosion, it is determined that the engine is in a cranking state and the process proceeds to step 54; It is determined that the explosion has been completed and the process moves to step 55. In Step 54, the value for cranking FSEI and FNE is set as the first drive cycle value Fl (Zl), and the process proceeds to Step 56. In Step 56, the drive cycle F of the refueling pump 17 is set. The first driving cycle value F) 121 is set as . In addition, the value FSEI
As shown in FIG. 4, the relationship between the engine cooling water temperature T and the optimal drive cycle of the refueling pump 17 is selected in advance and made into a map. Also.

The correction factor 1kFNE is to prevent the air-fuel ratio from being disturbed due to variations in cranking rotation speed.

As shown in FIG. 5, optimal values are selected in advance and mapped according to the cranking speed. On the other hand, if a complete explosion is determined in step 53 and the process proceeds to step 55, the value 5FWL for after a complete explosion is set as the second drive cycle value FH22, and the process proceeds to step 57. As shown in FIG. 6, the cycle value 5FIIL is obtained by preselecting and mapping the relationship between the cooling water temperature T and the optimum drive cycle of the refueling pump 17. Therefore, in the normal operating range, this period value 5FWL is larger than the period value FSEI zero FNE for cranking (
Next, in step 57, from the time when FH2I is updated, the value is set to 0.
It is determined whether or not 5 seconds have elapsed. If 5 seconds have elapsed, the process proceeds to step 59 via step 58; if not, the process directly proceeds to step 59. Step 5
In step 8, the drive cycle value FH2I of :JSl is updated to a value larger by 5 seconds, and the process moves to step 59. In step 59, it is determined whether the first drive cycle value F) 121 is equal to or greater than the second drive cycle (it FH22).

As a result, if it is determined that the first drive cycle value FH2I is not greater than or equal to the second drive cycle value FH22, the process advances to step 61, and the drive cycle FH2 of the refueling pump 17 is
A period value FHzI is set in the first driver 1 as follows.

On the other hand, the first drive cycle value FHzI is the second drive cycle value F
If it is determined that the value is equal to or higher than H22, the process goes to step 62 and sets the second drive vJ cycle value FH22 as the drive cycle FH2 of the refueling pump 17. In this way, the drive period FH2 is changed to step 56, 61 or 62.
After being motored at step 63, it is determined whether or not the cycle value Fl (Z is 400 msa or more, and if it is 400 gc or more, the process proceeds to step 64 and the refueling pump (SAP ) 17. On the other hand,
If it is determined that the period value FH2 is less than 400 sc, the process moves to step 65, and this period FH2-c
Output signal a indicating that the refueling pump 17 should be driven Next, proceed to step 66 shown in FIG. 3, and step 67 if the engine speed N is less than the complete explosion determination value TSTRT On the other hand, if the engine speed N is equal to or higher than the complete explosion determination value TSTRT, the process moves to step 68.

In step 67, the target throttle opening TA (iET is the throttle opening value O1 for non-complete explosion, for example, 5
°) is set and the process moves to step 71. On the other hand, step 6
In step 8, it is determined whether, for example, 5 seconds have elapsed since the time of complete explosion determination, and if 5 seconds have not elapsed from the time of complete explosion determination, the process goes to step 69; The process then proceeds to step 72. In step 69, a predetermined throttle opening θ7 for complete explosion corresponding to the first idle speed is set as the target throttle opening TACET, and the process proceeds to step 71. In step 71, throttle opening prospective control is performed to drive the valve opening adjusting means 5 so that the difference between the actual closing position of the throttle valve 2 and the target throttle opening TAGET falls within a certain tolerance value. The process is executed and the process returns to step 51. −
If 5 seconds have elapsed since t1 and the process moves to step 72, the actual engine speed N will change to the target idle speed set in advance according to the water temperature and whether the air conditioner is turned off or turned off. Idle rotational speed control is executed to drive the valve opening adjusting means 5 so that the valve opening degree converges to , and the process returns to step 51. The one or more steps are then repeated while the ignition switch is ON.

With such a configuration, during cranking, F is set as the refueling pump drive cycle FH2 in step 56.
SE 1 FNE is increased by 7-l, and θ1 is set as the target throttle opening TAGEτ in step 63, so that the closing position of the throttle valve 2 controlled by the valve opening adjusting means 5 is set to the above-mentioned θI (5 °), and the refueling pump 17 of the fuel injection means 4 is maintained at FSEI zero FM! It is driven at a certain period. Therefore, when a relatively large amount of fuel is supplied to the engine and the engine shifts to full explosion operation, at that point,
The target throttle and torque opening degrees TAGE in 11ii are updated to 02, and the valve opening adjustment ``5'' DC motor 26 operates and the closed position of the throttle valve 2 is set to the opening position corresponding to the fast idle rotation speed. It will be moved to .

Immediately after the complete explosion is completed, the first drive cycle FHzl is smaller than the second drive cycle FHz2, so the process proceeds from step 59 to step 65 via steps 61 and 63. The refueling pump 17 is the first
It is driven at a drive cycle FH2I.

Then, this first 1% dynamic period is updated to a larger value by 5 m5aa at step 58 every 0.5 seconds, so the discharge amount per unit time of the refueling pump 17 gradually decreases. It turns out. Then, when the drive cycle value FH2I of the wSl becomes larger than the second drive cycle value F)122, the process proceeds from step 2 59 to step 62 and 63 to step 65. , thereafter, the refueling pump 17 is driven based on the second driving cycle FH22.

In this way, according to the present system, during the transition period from when the complete explosion is determined to when the required time has elapsed, as shown in Fig. 17s7, the drive cycle F) of the fuel M supply cylinder/17
The one for cranking where IZ is set to a relatively small value (large for fuel discharge) F) The one for after complete explosion where IZl is set to a relatively large value (fuel discharge basket is small)
It is gradually switched to Z2 through an intermediate stage, and is vaporized by the refueling pump 17! ! The amount of auxiliary fuel supplied to 1 is gradually reduced. Therefore, at the same time as the closing position of the throttle valve 2 is shifted to the opening direction (θ1→0?), the amount of fuel to be replenished decreases at once (period F
sEItFNE+spwL) t6 Toira Kotoka fx
< fzru, Therefore, the phenomenon in which the air-fuel ratio suddenly becomes lean immediately after a complete explosion is determined can be reliably eliminated.

In one or more embodiments, (by increasing the wA!!l+period of the fuel supply pump every 1.5 seconds by 5 m5ec, the amount of replenishing fuel is gradually reduced during the transition period. However, the present invention is not necessarily limited to this, and various modifications such as making the update interval and update width of the drive cycle different from those described above are possible. [Effect] The present invention has the above configuration.

Even if the choke mechanism is eliminated, it is possible to bring the engine to a complete explosion without any difficulty, and it also avoids the inconvenience of the air-fuel ratio suddenly changing to the lean side immediately after a complete explosion is determined, causing engine malfunction or stalling. It is possible to provide an engine starting system that can reliably solve the problem with a simple configuration.

[Brief explanation of drawings]

FIG. 1 is a configuration explanatory diagram for clearly explaining the present invention. Figures 2 to 7 show an embodiment of the present invention, Figure 2 is a system explanatory diagram, EFS3 Figures a and b are flowcharts, and Figures 4, 5, and 6 are control setting conditions. FIG. 7 is an explanatory diagram for explaining the operation. l... Carburetor 2... - Slow 2 torque valve 4 @ φ Fuel injection means 5... Valve opening degree [! Means 6...Rotational speed detection means 7...Determination means 8...Opening degree command means 9--Fuel injection amount command means

Claims (1)

[Claims] A fuel injection means for supplying an amount of fuel corresponding to the injection command signal to the intake system, a valve opening adjustment means for moving the closing position of the throttle valve according to the opening/closing command signal, and a rotation speed for detecting the engine rotation speed. a detection means; a determination means for determining whether the engine is cranking or after completion of combustion based on the engine rotation speed detected by the rotation speed detection means; When it is determined that the operation has shifted to explosion operation, the valve opening degree adjusting means is operated by the required amount in the opening direction by switching from the opening/closing command signal output state for cranking to the opening/closing command signal output state for after complete explosion. an opening command means and an injection command signal output state for after complete explosion from an injection command signal output state for cranking when it is determined by the determination means that the engine has transitioned from cranking operation to complete explosion operation; An engine starting system characterized by comprising: a fuel injection amount command means that transitions through a transition period and gradually reduces the fuel injection amount by the fuel injection means to a value for after a complete explosion during the transition period.