JPS61145333A - Starting system in engine - Google Patents

Abstract

PURPOSE:To eliminate deterioration of starting ability of an engine due to lack of fuel supply, by inhibiting the supply of fuel from shifting into its cranking fuel supply condition until the supply of fuel for prestarting of the engine is completed. CONSTITUTION:In a control device for controlling fuel injected from a fuel injection means 4 into a carburettor 1, there is provided a prestarting injection instructing means 7 for sustaining the issuance of an injection instruction signal to the fuel injection means 4 during the period from the time when an ignition switch 34 is turned on to the time when the discharge of a predetermined amount of fuel is completed, irrespective of whether the cranking of the engine is started or not. Further, there is provided a cranking detecting means 8 for allowing a cranking time injection instructing means 9 to deliver an instruction of cranking time injection when an injection instructing signal from a prestarting injection instructing means is interrupted during cranking operation.

Description

[Detailed description of the invention]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a starting system mainly applied to automobile engines.

[Conventional technology]

Gasoline engines require a particularly rich air-fuel mixture when starting, so they are generally equipped with a choke system as a starting system. However, in the choke system, a choke valve is installed in the vaporizer, and the pulp is opened and closed manually or automatically. It is essential to provide a mechanical structure such as a link mechanism for this purpose. This inevitably complicates the structure of the fuel supply system, which is an obstacle to simplifying the structure of the engine as a whole. As a prior art of a starting system developed to deal with such inconveniences, a patent application filed earlier in 1983-2378
There is one as shown in Publication No. 3°2. That is,
This starting system 1 includes a fuel injection means for supplying an amount of fuel corresponding to an injection command signal, a rotation speed detection means for detecting the engine rotation speed, and a state S ( The ignition switch has a cranking detection means that detects whether the engine is stopped or cranking, and a cranking detection means that discharges a predetermined amount of fuel when the ignition switch is turned on. pre-start injection command means for outputting an injection command signal to the fuel injection means to indicate that the engine is in cranking operation; and an injection command means for cranking which outputs an injection command signal. However, with this type of conventional system, a problem arises when the starter is activated immediately after the ignition switch is turned on to shift to cranking operation. i.e. in such a system. A predetermined amount of fuel is supplied at the maximum speed before starting, and then when cranking operation is started, the fuel injection means is injected at a predetermined speed set for cranking in accordance with the water temperature, etc. By continuing to drive the engine, the amount of fuel is increased. However, in such a system, if the system shifts to cranking operation before the supply of fuel before starting is finished, the fuel supply speed by the fuel injection means will change to the speed for cranking from the point of transition. As a result, the expected amount of fuel cannot be supplied, resulting in the inconvenience that engine startability deteriorates due to fuel shortage. [Problem to be Solved by the Invention J] The present invention solves the problem that if the starter is activated immediately after turning on the ignition switch to shift to cranking operation, the starting performance of the engine will deteriorate due to insufficient fuel supply. The U objective is to reliably solve the problem. Means for Solving Problem E] In order to achieve the above objects, the present invention is configured such that the state cannot be shifted to the fuel supply state for cranking until the supply of fuel for pre-starting is completed. It is characterized by this. In other words, as shown in FIG. 1, the engine starting system according to the present invention includes a fuel injection means (4) that supplies an amount of fuel corresponding to the injection command No. cranking detection means (8) for detecting whether the ignition switch (
34) continues to output an injection command signal to the fuel injection means (4) regardless of whether cranking has started or not until a preset amount of fuel has been discharged. l+ front injection command means (7) and the cranking detection means (8) have detected that the engine is in cranking operation, and the injection command signal from the start commercial injection command means (7) has been detected. Injection command means for cranking (9) outputs an injection command signal for cranking to the fuel injection means (4) when the fuel injection means (4) is interrupted.
It is characterized by comprising the following. [Operation 1] According to such a configuration, first, when the ignition switch (34) is turned on, the pre-start injection command means (7) is activated.
) outputs an injection command signal to the fuel injection means (4). Then, this injection command signal is outputted regardless of whether or not cranking has started until the preset fuel in the lid is completely discharged. Therefore, even if you activate the starter and shift to cranking operation immediately after turning on the ignition switch (34), the injection command signal will immediately change from the one for before starting to the one for cranking. In other words, after reliably supplying and cooling the first fuel necessary for starting preparations, the system shifts to the refueling system for cranking. E Example j An example of the present invention will be described below with reference to FIGS. 2 to 8. FIG. 2 is an explanatory diagram of the 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 1, 3 is a float chamber, and 4 is an explanatory diagram of an engine starting system according to the present invention.
5 is a fuel injection means for supplying an amount of fuel corresponding to the injection command signal a into the carburetor l forming a part of the intake system; 5 is a fuel injection means for closing the throttle valve 2 in response to the opening/closing command signal A; 6 is a rotation speed detection means for detecting the rotation speed of the engine; 10 is an injection command means for starting n11; 7. This is a microcomputer system that plays the role of cranking detection manual punch 8 and cranking 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 float chamber 3 via an out-left passage 16 having a check valve 15. An electromagnetic refueling pump (SAP) 17 opened to the intake passage 1a of the carburetor l, and the refueling pump 17 is operated at a cycle FH2 corresponding to the injection command signal a supplied from the microcomputer system 10.
and a driver 18 for driving. The refueling pump 17 houses a piston 22 in a cylinder 21 that forms a pump chamber 19, and performs a pumping function by moving the piston 22 forward and backward by the urging force of a spring 23 and the electromagnetic attraction force of a solenoid 24. It is configured as follows. Further, the driver 18 is connected to the solenoid 24.
+iiij refueling pump 17 by applying a pulse voltage to
The piston 22 is moved forward and backward, and the fuel discharge level of the refueling pump 17 can be adjusted by changing the pulse period FH2 of the applied voltage. That is, each time one pulse of driving voltage is applied to the solenoid 24 of the fuel replenishment pump 17 to cause the piston 22 to reciprocate once, a fixed amount (for example, 0.04 cc) of fuel is discharged from the refueling pump 17. It has become so. Therefore, when the pulse period FHz is increased, the pulse interval becomes longer and the fuel discharge shield per unit time is reduced;
When IZ is decreased, the pulse interval becomes shorter and the fuel discharge per unit increases. On the other hand, the valve opening yA adjusting means 5 includes an actuator 25 that locks the rotating arm 2b integrally protruding from the support shaft 2a of the throttle valve 2, and an actuator 25 that moves the actuator 25 forward and backward.
The silence of iJ throttle valve 2! D move the position
The IK includes a C motor 26 and a driver 27 that applies a DC voltage in pulses to the DC motor 26 to operate the DC motor 26 by an amount corresponding to an opening/closing command signal. To be more specific, the actuator 25 is in the shape of a nut, and is screwed into a feed screw portion 26b provided at the output @26a of the DC motor 26 while its rotation is prohibited by a guide member (not shown). The rotary arm 2b of the throttle valve 2 can be locked at its tip. Note that 2c is a spring that biases 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). Moreover, the microcomputer system 10 is. It includes a central processing unit 28, a memory 29, and interfaces 31 and 32. Then, the signal C from the one-rotation speed detection means 6, the signal d from the water/humidity sensor 33, and the signal e from the ignition switch 34 are input to the interface 31, and the valve opening adjustment means 5 is input from the interface 32.
The above-mentioned signals a and b are respectively outputted toward the city record fuel injection 1,000 strokes 4. The rotational speed detection means 6 is for detecting the rotational speed of the engine, and uses, for example, an ibnirasilane pulse. The water temperature sensor 33 is for detecting the engine cooling water temperature.For example, the water temperature sensor 33 includes a thermistor that converts the water temperature into an analog electrical signal, and an A/D converter (not shown) that converts the output of this thermistor into an electrical signal. ). And, the microcomputer system IO has the following:
It has a built-in pro-daram as schematically shown in Figures a and b of tjS3. First, when the ignition switch 34 is turned on, fl A is set to O in step 51, and the process proceeds to step 52. In step 52, the engine rotational speed N and engine cooling water temperature T are input, and the process moves to step 53. In step 53, it is determined whether the engine rotation speed N detected by the rotation speed detection means 6 is, for example, 50 rpm or more, and if it is less than 50 rpm, the engine starts! The state of JHtiJ! If it is determined that it is on an island, the process proceeds to step 54, and if it is determined that 50"p■ or more, the process proceeds to step 55. In step 54, it is checked whether i4A is 0, and if it is 0, it is checked. If it is not 0, proceed to step 57 via step 56, and if it is not 0, proceed to step 52.
Return to In step 56, the value A is set to 1,
In step 57, the drive period FH of the refueling pump 17 is
z its minimum value FlIZmin (for example, 50⅑5e
Set c). Then, in step 58, the pre-start SAP drive command value TBSE is set in the pump drive command flag WiF. This SAP drive command (I
BsE is for specifying how many times the refueling pump 17 is driven to replenish fuel before starting, and is ff1.
As shown in FIG. 7, the optimum f#'I according to the level of the engine cooling water mT is selected in advance and mapped. On the other hand, if the process proceeds to step 55, the engine speed N is selected in advance according to the water temperature T and is mapped to complete explosion determination I1↑5TRT (for example, 800 to 440 r
pm) Judge whether it is -1- or apricot. As a result, if the engine speed N is not equal to or higher than the complete explosion determination value TSTRT, it is determined that the engine is in a cranking state and the process proceeds to step 61. Determine that the explosion is complete and proceed to step 6
Move on to 2. In step 61, it is determined whether the pump drive command flag (Ij Supply pump drive cycle FH2
Then, the value FSEItFNE for cranking is set and the process proceeds to step 64. 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. In addition, the correction coefficient aFNε is used to prevent the air-fuel ratio from being disturbed due to variations in the cranking rotation speed. These are selected in advance and mapped out. -・I completely exploded at step 55! If the determination is made and the process proceeds to step 62, a value 5FWL for use after a complete explosion is set as the driving cycle F)12 of the refueling pump 17, and the process proceeds to step 64. In step 64, it is determined whether the cycle value FIZ is 400 m5ec or more, and if it is 400 mg@c or more, the process proceeds to step 65, and if it is less than 400 m5ec, the process proceeds to step 6.
Move on to 6. In STEP 2 PRO 5, the SAP@@ flag gaF is set to O, and the fuel injection pump 17 is stopped. On the other hand, in step 66, the flag value is set to 1, and the refueling pump 17 is driven at a cycle FH2. The main routine shown in FIG. 3(a) is as follows:
The pump drive interrupt routine shown in FIG. 3(b), which will be described later, takes 501 seconds, while
In order to interrupt the main routine at the above-described time intervals, if the flag value F is set to 1 every time the step 66 is passed, the refueling pump 17 will be continuously driven. Next, the interrupt routine shown in FIG. 3(b) will be explained. This interrupt routine interrupts the main routine in step 57, 62, and 63 of the main routine shown in FIG. It is determined whether the flag value F is O or a value of 1 or more, and if F is 0, the current interrupt is terminated without driving the refueling pump 17. On the other hand, the flag value F
If it is determined that is a value of 1 or more, step 72
Then, in step 73, the flag value F is set to 1 to operate the refueling pump 17 for one pulse.
update to a smaller value and end the interrupt for that time. In addition, the valve opening degree tA! ! The i-hand setting 5 is subjected to M control in a first-order manner. That is, before starting and during cranking,
The closed position of the throttle valve 2 is operated to a position where the throttle opening degree for non-complete explosion can be maintained, for example, 5 degrees, and then stopped. When a complete explosion is determined, the closing position of the slow two-torque valve 2 is quickly moved to a position corresponding to the fast idle rotation speed. After a certain period of time has elapsed since the complete explosion determination, the closed position of the throttle valve 2 is feedback-controlled so that the engine speed N converges to a predetermined target idle speed. Next, the operation of this embodiment will be explained. First, when the ignition switch 34 is turned on, A=0, so steps 52 → 53 → 54 → 56 → 57 → 5 are performed only for the first time.
The control proceeds according to steps 8, and a minimum value of 50 m5ec is set as the driving cycle F)12 of the refueling pump 17, and a value of 1 or more corresponding to the water temperature is set to the WIA full command lug [F]. SE is set. As a result, the interrupt routine shown in FIG. 3 is interrupted every 50 ms@c, and each time the refueling pump 17
It is driven pulse by pulse, and the 7 lags (II
F is subtracted by 1. Therefore, the FB that was initially set
The heavy fuel replenishment pump 17 operates SE times to replenish the vaporized fuel ′j4t with the necessary fuel before starting. On the other hand, after the ignition switch 34 is turned ON, when the starter is activated and the cranking operation is started, the process proceeds from the snap 53 to step 55 to step 61.
If the pre-start refueling is not completed and the flag value F is 1 or more, the process returns to step 52, but the pre-start refueling is completed and the If the flag value F is 0, the process normally proceeds to steps 63 → 64 → 66 and the period FSE set for cranking is set to 1 FM! (greater than the 50 s@a), the refueling pump 17 is driven. When the engine shifts from this state to a complete explosion operation, the process proceeds from step 53 to step 55 to step 62, where the refueling pump 17 is driven at a period of 5FWL set for use after a complete explosion. In this way, before starting, the amount of fuel necessary for starting preparation is rapidly supplied, and during cranking and after completion of complete combustion, fuel is supplied at a rate that corresponds to the operating state. However, in this system, even if the engine shifts to cranking operation, the control is not switched to fuel replenishment control for cranking unless the supply of fuel for starting is finished. Therefore, even if the starter is operated and cranking is started after σ when the ignition switch 34 is turned on, the high-density starting fuel is
Fuel supply m control for Ni is continued. In other words, with the conventional one! As shown in li'S'l, if cranking is started in the middle of the fuel supply control for the starting song, the fuel supply for the starting song is interrupted at that point.
Since the system shifts to fuel supply control for cranking, the amount of fuel supplied may be insufficient. However, as shown in Fig. 8, with this system, even if cranking operation is started during the fuel supply control for the start fNJ river, the cranking operation will start as soon as the pre-start fuel supply control is completed. Shifts to fuel supply control for Therefore, it becomes possible to supply starting preparation fuel to the engine as planned, and good startability can be ensured. In the second embodiment, a case has been described in which whether or not cranking has started is detected based on the engine rotation speed, but the present invention is not necessarily limited to this, for example. It may also be possible to detect whether or not the engine has shifted to cranking operation by turning the starter switch ON or OFF. E Effects of the Invention J Since the present invention has the above-described configuration, it is possible to easily bring the engine to a complete explosion even if the chime mechanism is abolished, and moreover, it is possible to easily bring the engine to a complete explosion even if the ignition switch is turned on. Even if you activate the starter immediately after starting cranking operation, there will be no problem that the amount of fuel replenished will become unreasonably small. It can provide a starting system.

[Brief explanation of drawings]

FIG. 1 is a configuration explanatory diagram for clearly explaining the present invention. 2 to 8 show an embodiment of the present invention, FIG. 2 is a system explanatory diagram, FIGS. 3 a and b are flowcharts, FIGS. 4, 5, 6, and 0's7 FIG. 11 is an explanatory diagram for explaining the control setting conditions, and FIG. 8 is an explanatory diagram of the operation. 9th
The figure is an operation theory til1 diagram corresponding to the fjSB diagram showing a comparative example. 1.Fist carburetor 2.II@throttle valve 4-Fist fuel injection means 6.. - Rotation speed detection hand blow 7..4 Injection command means for starting button 1 8.. -Cranking detection hand blow

Claims (1)

[Claims] A fuel injection means for supplying an amount of fuel corresponding to the injection command signal to the intake system, a cranking detection means for detecting whether or not the engine is in a cranking operation state, and a cranking detection means for detecting whether or not the engine is in a cranking operation state. The engine is cranked by the pre-start injection command means, which continues to output an injection command signal to the fuel injection means until a set amount of fuel is discharged, regardless of whether cranking has started, and the cranking detection means. cranking for outputting an injection command signal for cranking to the fuel injection means when it is detected that the engine is in a ranking operation and the injection command signal from the pre-start injection command means is interrupted; 1. An engine starting system, comprising: an injection command means.