JPH0213733Y2 - - Google Patents

Description

[Detailed explanation of the idea]

(Technical Field) The present invention relates to an auxiliary air amount control device for an internal combustion engine. (Prior art) In general, in internal combustion engines for automobiles, air volume is insufficient to ensure the amount of air during idling when the intake throttle valve is closed, or when auxiliary equipment such as an air conditioner is operated during idling. In order to compensate for this, auxiliary air is supplied by means other than throttle valve operation. For example, Fig. 1 shows an example applied to an electronically controlled fuel injection engine (for example, in the Examination of Inventions Related to Microcomputer Application Technology edited by the Japan Patent Office,
Operational Guidelines, published by Japan Institute of Invention and Innovation, December 1957, p. 44). In the figure, 1 is the engine main body, intake air is supplied to each cylinder from an air cleaner 2, an air flow meter 3, a throttle chamber 4, and each branch of an intake manifold 5, and fuel is injected by a fuel injector 6. Ru. Here, the flow of intake air is controlled by a throttle valve 7 in a throttle chamber 4 that is linked to an accelerator pedal.
The throttle valve 7 is almost closed during idling. Air flow during idling passes through a bypass port 8, is regulated by an idle adjustment screw 9 attached to this port 8, and passes through a bypass passage 10 that communicates the upstream and downstream sides of the throttle valve 7. An idle control valve 11 provided in this passage 10 ensures the appropriate amount of air. Idle control valve 11 as an auxiliary air amount control valve
consists of a valve body 12 provided in the bypass passage 10, a diaphragm 13 connected to the valve body 12, and a negative pressure operating chamber 15 equipped with a spring 14 that biases the diaphragm 13. Room 15
diaphragm 1 depending on the increase or decrease of negative pressure introduced into
3, the lift amount of the valve body 12 is changed to increase or decrease its opening degree. This negative pressure working chamber 15 communicates with the intake passage downstream of the throttle valve 7 through a constant pressure valve 17 through a negative pressure introduction passage 16, and communicates with the intake passage upstream of the throttle valve 7 through an atmosphere introduction passage 18 through a pulse solenoid valve 19. It communicates with Therefore, by opening and closing the pulse solenoid valve 19, the degree of opening of the idle control valve 11 is controlled by changing the dilution ratio of the negative pressure introduced into the negative pressure working chamber 15 with the atmosphere. The pulse solenoid valve 19 is controlled by a control unit 20 of a microcomputer, for example. The control unit 20 mainly includes a microprocessor (central processing unit) 21, a memory (storage device) 22, and an interface (input/output signal processing circuit) 23. The rotation speed of the engine 1 is detected by a rotation speed sensor 24 and inputted to the interface 23 as a digital signal. (Actually, a crank angle sensor is used) and engine temperature (for example, cooling water temperature) is detected as an analog signal by a thermistor-type water temperature sensor 25 and input as a digital signal via an A/D converter 26. The interface 23 also includes a throttle valve switch 27 that detects that the throttle valve 7 is in the fully closed position, a neutral relay 28 that detects that the automatic transmission is in the neutral position, and a controller that detects whether the air conditioner is on or off. Air conditioner switch 29 that detects the OFF state
ON and OFF signals are input from and, respectively. The throttle valve switch 27 is an analog type sensor using a variable resistor, and its signal is sent to the A/D.
Although it is shown as being input via the converter 30, in reality, an ON/OFF type switch that detects the fully closed position is used. In the control unit 20, the information stored in the memory 22 is
The basic control value ISC _TW corresponding to the cooling water temperature (hereinafter abbreviated as "water temperature") Tw is stored in advance as a data table in the ROM (read-only memory), and the table is retrieved according to the signal from the water temperature sensor 25. The corresponding basic control value ISC _TW
Read out. This basic control value ISC _TW is set when the air conditioner is on,
Depending on whether the automatic transmission is in the OFF state and whether the automatic transmission's neutral relay is in the ON or OFF state, the corrected duty ratio (valve opening time and valve closing time) is corrected with a different value in each case. The pulse solenoid valve 19 is controlled in open loop according to the time ratio). The correction value ISC _AT of the basic control value ISC _TW is given as shown in the following table. Note that the unit of both ISC _TW and ISC _AT is %, but % is omitted in the following explanation.

[Table] In other words, the basic control value ISC _TW is not corrected when the air conditioner is OFF with a manual transmission specification, or when the air conditioner is OFF and the neutral relay is ON (in the neutral position) with an automatic transmission specification, but when other In some cases, it is corrected according to the load condition. A flowchart for executing this control is shown in FIG. 2 for automatic transmission specifications. In addition, P ₁ in the figure
~ _P10 indicates each step. The control calculation is executed, for example, once per rotation or once every fixed period of time (for example, once every 0.1 seconds). At _P1 , the water temperature is input, and at _P2 , a table of basic control values ISC _TW determined for the water temperature is looked up and stored in the register in the microprocessor 21. Next, check whether the unitral relay is ON in P ₃ , and if the neutral relay is ON, check in P ₄ whether the air conditioner switch is ON or OFF. If the neutral relay is ON and the air conditioner switch is OFF, the correction value ISC _AT is set in P ₆ .
is zero, and if the neutral relay is ON and the air conditioner switch is ON, the correction value ISC _AT is set to 9 in _P7 . If the neutral relay is OFF, check whether the air conditioner switch is ON or OFF in P _5. If the neutral relay is OFF and the air conditioner switch is OFF, set the correction value ISC _AT to 1.5 in P ₅ , and check whether the neutral relay is OFF and the air conditioner switch is OFF. If the air conditioner switch is ON
Set the correction value ISC _AT to 10.5 in P ₉ . These correction values are added to the basic control value ISC _TW ,
Transfer this result to the output register at _P10 and move on to the next control program. By the way, in such control calculation, the correction value
In order to increase or decrease ISC _AT by a predetermined amount at once, an automatic transmission specification equipped with a lock-up mechanism (provided to improve output and fuel efficiency by directly connecting the output shaft of the engine and the input shaft of the transmission) In a car, when the air conditioner is turned on while driving in a locked-up state (in a car with a manual transmission, the gear is set to a position other than neutral), negative pressure is introduced into the negative pressure operating chamber of the idle brake valve. Since the pressure changes in steps, the amount of auxiliary air also changes in steps, and the torque generated by the engine changes suddenly.
This may cause an unpleasant shock to the driver. (Purpose of the invention) Therefore, the present invention is such that the output shaft of the engine and the input shaft of the transmission are directly connected, and in this state, the auxiliary load such as the air conditioner is changed from the operating state to the non-operating state or vice versa. If the value changes (at the time of load fluctuation), the correction value
The purpose of the present invention is to provide an auxiliary air amount control device that gradually changes ISC _AT to suppress sudden changes in torque, reduce unpleasant shocks during load fluctuations, and improve driveability. (Structure and operation of the invention) FIG. 3 is an overall configuration diagram for clearly showing the structure of the invention. An idle control valve 11 as an auxiliary air amount control valve is provided in a bypass passage 10 that communicates between the upstream and downstream sides of the throttle valve 7 of the engine 1. (The negative pressure working chamber 15 is divided and the valve body 1
2, a spring 14 that biases the diaphragm 13 in the valve opening direction (downward in the figure), a negative pressure introduction passage 16, an atmosphere introduction passage 18, and an atmosphere introduction passage 18 communicating with the negative pressure working chamber 15, respectively. A pulse electromagnetic valve 19) installed in the bypass passage 10 increases or decreases the flow rate of the bypass passage 10. The pulse solenoid valve 19 includes a means A for setting a basic control value according to the temperature detected by an engine temperature sensor (for example, a water temperature sensor) 25, and an auxiliary machine (air conditioner, etc.).
a means C for determining whether a load (external load) B is in an operating state or a non-operating state; and a value for increasing or decreasing the basic control value by a predetermined amount at a time according to the result of this determination; It is driven by a device comprising a means D for correcting a pulse signal having a predetermined duty ratio (valve opening time ratio) determined from the basic control value based on the correction value. Here, when the duty ratio to the pulse solenoid valve 19 is increased or decreased by a predetermined amount at once, the control negative pressure introduced into the negative pressure working chamber 15 changes in a stepwise manner, so that the idle control valve 1
The flow rate passing through 1 changes all at once. The present invention provides an auxiliary air amount control device constructed in this manner, which includes means E for determining whether the output shaft of the engine and the input shaft of the transmission are in a direct connection state, and the external load B is in an operating state. means F for determining whether the state has changed from the operating state to the non-operating state or vice versa; or vice versa, means G for instructing the pulse signal correction means D so that the correction value of the basic control value is gradually increased or decreased. In this way, the flow rate passing through the idle control valve 11 will gradually increase even if the air conditioner is started or stopped while driving with the gear in a position other than neutral or in a locked-up state. Since the torque increases or decreases gradually, there is no sudden torque change. In this case, it can be said that shock due to torque changes is most easily transmitted to the driver when the engine and transmission are directly connected, but drivability is improved because sudden torque changes are avoided. . On the other hand, if the bypass flow rate is gradually increased until the air conditioner starts operating during idling operation when the gear is in the neutral position, it may not be able to cope with the load of the air conditioner, and the engine may stall. However, in such a case, the bypass flow rate is suddenly increased in response to the start of operation of the air conditioner, thereby preventing the engine from stalling. (Example) The following will explain based on the illustrated example. FIG. 4 is a schematic diagram of the first embodiment of the present invention.
This is an example of application to an automatic transmission specification with a lock-up mechanism. The lock-up mechanism has a wet single-plate clutch (lock-up piston) between the torque converter and the front cover, and converter pressure is guided to the lock-up piston by switching the lock-up control valve, directly connecting the lock-up piston to the torque converter. It is used to transmit power. This lock-up control valve has line pressure acting on one end, and this line pressure is controlled by turning the lock-up solenoid ON and OFF. Therefore, when the lock-up solenoid is ON, the engine and the transmission are directly connected, and when the lock-up solenoid is OFF, the direct connection is released. Here, to determine whether the output shaft of the engine and the input shaft of the transmission are directly connected, it is sufficient to check whether the lock-up solenoid is in the ON state. 31 in the figure is this lock-up solenoid, and ON/OFF signals of the lock-up solenoid 31 are output to the control unit 20. Based on this signal, the control unit 20 checks whether the automatic transmission is in a lock-up state or not, and if it is not in a lock-up state, the control unit 20 sets a correction value ISC to be added to the basic control value ISC _TW in response to load fluctuations caused by air conditioners, etc., as in the past. _AT is changed stepwise, and when in a lock-up state, the correction value ISC _AT is gradually changed in response to load fluctuations caused by air conditioners, etc. Since the other components are the same as those in FIG. 1, the same components are given the same reference numerals and their explanation will be omitted. The operation of the above configuration will be explained based on the flowchart of FIG. Control calculations are performed at predetermined intervals (for example, once every 0.1 seconds)
_P3 to _P18 indicate each step. However, P ₁ and P ₂ (see Figure 2) are omitted. P ₃ checks whether the neutral relay is ON, and if the neutral relay is not ON,
Check whether it is in lockup state with P ₁₁ ,
If the air conditioner is locked up, check whether the air conditioner switch is ON or OFF on page ₁₂ . If the neutral relay is ON, go to P ₄ (see Figure 2), and if the neutral relay is OFF but is not in the lock-up state, go to P ₅ (see Figure 2).
Check whether the air conditioner switch is ON or OFF, and perform conventional control calculations according to the steps shown in Figure 2 below. If it reaches P ₁₂ , that is, if the gear is in a position other than neutral and the air conditioner switch is in the ON state, the flag FLG will be set to 1 in P ₁₃ .
Check whether it is. FLAG indicates whether or not the air conditioner was operating at the time of the previous calculation. When FLAG is 1, it means that the air conditioner was not operating.
When FLAG is zero, it indicates that the air conditioner is in operation. Therefore, if FLAG is 1 in P ₁₃ , it means that the air conditioner was inactive during the previous calculation, but it is in the operating state during the current calculation, so FLAG is set to zero in P ₁₄ (the air conditioner is not activated). (operating state) and set the count value of the counter to 1. In this case, since it is immediately after the air conditioner starts operating, the value 2.5 obtained by adding this count value 1 to 1.5 in P ₁₅ is set as ISC _AT . By setting the count value to 1 at P ₁₄ and P ₁₇ , the above counter increases the count value by 1 in synchronization with the predetermined cycle of the control calculation (which is executed, for example, once every 0.1 seconds like the control calculation). The operation is shown in the flowchart of FIG. In other words, at P ₂₀ , add 1 to the count value from the previous calculation to obtain the count value from the current calculation,
This count value increases by 1 for each calculation.
However, in P ₂₁ it is checked whether the count value is 10 or not, and if the count value is 10, the next count value is set to 9 in P ₂₂ , so the count value does not exceed 9. Note that the initial value of the counter is 0. Therefore, as shown in Fig. 7, the count value increases by 1 at predetermined time intervals from the time of calculation when the count value is set to 1, and after reaching 9, it remains a constant value until it is set to 1 again. Maintain 9. If FLAG is not 1 in P ₁₃ , it indicates that the air conditioner has been operating continuously since the previous calculation. In this case, add the count value (2 to 9) of the current calculation to 1.5 in P ₁₅ . ISC _AT . Return to P. ₁₂ , and if the air conditioner switch is not in the ON state, check whether FLAG is zero in P. ₁₆ . If FLAG is 0, this indicates that the air conditioner was operating during the previous calculation but is not operating during the current calculation, so set FLAG to 1 (air conditioner is not operating) in _P17 . and set the count value of the counter to 1. In this case, it is 9 on page ₁₈ because the air conditioner has just stopped operating.
The difference 8 between the current count value 1 and the current count value 1 is added to 1.5, and the value 9.5 is set as ISC _AT . If FLAG is not zero in P ₁₆ , it indicates that the air conditioner has been inactive since the previous calculation, and in this case, in P ₁₈ , the value obtained by subtracting the count value of the current calculation from 9 is added to 1.5. , this added value is ISC _AT . As mentioned above, the count value increases by 1 from 1 to 9, so (9 - count value)
Conversely, it decreases by 1 from 8 to 0. The ISC _AT calculated in this way is the basic control value ISC _TW
and move this result to the output register at P ₁₀ ,
Move on to the next control program. Here, we will specifically explain the case where, when the automatic transmission is in the lock-up state, the air conditioner is activated at point a and deactivated at point b as shown in FIG. Before the air conditioner operates, FLAG is 1 and the count value of the counter is 9, so the control calculation is P ₃ −P ₁₁ −
Processed in the order of P ₁₂ −P ₁₆ −P ₁₈ , and ISC _AT is 1.5. When the air conditioner switch changes from the OFF state to the ON state at point a, the current calculation is P ₃ −P ₁₁ −P ₁₂ −P ₁₃ −
Processed in the order of P ₁₄ - P ₁₅ , ISC _AT is 2.5. The next calculation is P ₃ −P ₁₁ −P ₁₂ −P ₁₃ −P ₁₄ −
P ₁₅ is processed in the order, and the counter is processed in the order of P ₂₀ −P ₂₁ , P ₂₀ −P ₂₁ −P ₂₂ in synchronization with this calculation, so ISC _AT increases by 1 from 3.5 to 10.5 and becomes 10.5 After reaching , it will remain at 10.5. On the other hand, the air conditioner switch is turned on at point b.
Immediately after turning off, P ₃ −P ₁₁ −P ₁₂ −
Processed in the order of P ₁₆ −P ₁₇ −P ₁₈ , and ISC _AT becomes 9.5. Subsequent calculations will be processed in the order of P ₃ −P ₁₁ −P ₁₂ −P ₁₆ −P ₁₈ , and in synchronization with this calculation, the counter will be processed in the order of P ₂₀ −P ₂₁ and P ₂₀ −P ₂₁ −P ₂₂ . Because of processing, ISC _AT decreases by 1 from 8.5 to 1.5 and becomes 1.5
After reaching , it remains at 1.5. Therefore, when the automatic transmission is in the lock-up state, load fluctuations caused by the air conditioner (air conditioner switch from ON to OFF or OFF to ON)
When , ISC _AT increases from 1.5 to 10.5 as shown in Figure 7.
This correction value will be increased or decreased by 1 between
When the control unit 20 controls the duty ratio of the pulse signal using the value obtained by adding ISC _AT to the basic control value ISC _TW , the air dilution ratio by the pulse solenoid valve 19 changes smoothly, and the flow rate passing through the idle control valve 11 suddenly changes. There is no increase or decrease. On the other hand, if the air conditioner switch is turned from ON to OFF or from OFF to ON while driving without lock-up or when the gear is in the neutral position, ISC _AT will increase or decrease in steps (different from the above). P ₁₁ −P ₅ −P ₈ , P ₁₁ −P ₅ −P ₉ or
P ₃ −P ₄ −P ₆ , P ₃ −P ₄ −P ₇ ). Here, if the flow rate passing through the auxiliary air amount control valve is suddenly increased or decreased, a correspondingly large torque is generated, so that load fluctuations caused by the air conditioner can be countered with a good response, and engine stalling can be prevented. In other words, if the engine is not locked up or the gear is in the neutral position, even if there is a sudden change in torque, it will not be noticeable to the driver, and even if it is felt, it will not cause the engine to stall. If this occurs, it becomes impossible to operate the engine, so in such a case, priority is given to preventing engine performance from becoming defective rather than operational performance. FIG. 8 is a schematic diagram of the second embodiment of the present invention.
This is an example of application to manual transmission specifications. To determine whether the output shaft of the engine and the input shaft of the transmission are directly coupled, a neutral switch 32 detects that the transmission is in the neutral position, and a neutral switch 32 detects that the clutch is disengaged. It may be based on the signal from the clutch switch 33, and the ON,
The OFF signal is output to the control unit 20. The other components are the same as in FIG. 1, and the actions performed by the control unit 20 are shown in the flowchart of FIG. Due to the difference in transmission specifications, as shown in Table 1 above for manual transmissions, the increase/decrease range of the correction value ISC _AT is as small as 5. Therefore, the count value of the counter is changed from 1 to 5 for a predetermined period of time. (P ₃₆ to _{P 38} in Figure 10). In addition, for automatic transmission specifications, the correction value ISC _AT can be increased or decreased depending on whether the air conditioner is on or off, as well as whether the neutral relay is on or off. However, with manual transmission specifications, it is simple as there is no correction due to the latter, and in P ₂₀ , the count value indicating the correction due to the former becomes ISC _AT as is. In this example, the air conditioner switch is turned on when the engine output shaft and the transmission input shaft are directly connected.
When it changes from OFF and OFF to ON, the correction value ISC _AT is gradually increased/decreased as in the first embodiment (P. ₂₄ -
P ₂₅ −P ₂₆ −P ₂₇ −P ₂₈ −P ₂₉ , P ₂₄ −P ₂₅ −P ₂₆ −P ₂₇ −
P ₂₉ or P ₂₄ −P ₂₅ −P ₂₆ −P ₃₀ −P ₃₁ −P ₃₂ , P ₂₄ −P ₂₅
−P ₂₆ −P ₃₀ −P ₃₂ ). In both the first and second embodiments, the air conditioner is used as a variable load, but the same applies to loads of auxiliary equipment other than the air conditioner, such as electric fans, and the degree of increase or decrease can be freely set. (Effects of the invention) As described above, according to the invention, when the engine is affected by load fluctuations due to air conditioning, etc., the amount of auxiliary air is increased or decreased in steps, while the engine and power transmission system are connected without slipping. Only if
By gradually changing the amount of auxiliary air in response to changes in the load of the air conditioner, etc., it is possible to avoid unpleasant shocks when driving in a position other than neutral or in a locked-up state, and to improve the power transmission between the engine and the engine. If the system is not coupled without slipping, engine performance is given priority and engine stalling is prevented.

[Brief explanation of the drawing]

Figure 1 is a schematic configuration diagram of the conventional device, and Figure 2 is the
3 is a flowchart showing arithmetic processing of the control unit in the figure. FIG. 3 is an overall configuration diagram of the present invention, FIG. 4 is a schematic configuration diagram of the first embodiment of the invention,
5 is a flowchart showing the arithmetic processing of the control unit in FIG. 4, FIG. 6 is a flowchart showing the arithmetic processing of the count value used in FIG. 5, and FIG. This is an example timing chart. FIG. 8 is a schematic configuration diagram of the second embodiment of the present invention, FIG. 9 is a flowchart showing the calculation processing of the control unit in FIG. 8, and FIG. 10 is the calculation of the count value used in FIG. It is a flowchart showing processing. 7...Throttle valve, 10...Bypass passage,
11... Idle control valve, 12... Valve body, 13...
...Diaphragm, 14...Spring, 15...
Negative pressure working chamber, 18...Atmospheric introduction passage, 19...Pulse solenoid valve, 25...Water temperature sensor, 28...Neutral relay, 29...Air conditioner switch, 3
1... Lock-up solenoid, 32... Neutral switch, 33... Clutch switch.

Claims (1)

[Scope of utility model registration request] An auxiliary air flow control valve is installed in a bypass passage that communicates the upstream and downstream of the throttle valve, and increases or decreases the flow rate of this passage, and the load from the auxiliary equipment is in operation.
means for determining whether the device is in an inactive state;
A means for increasing or decreasing a basic control value to the auxiliary air amount control valve by a predetermined amount at a time in accordance with the determination result, and a means for driving the auxiliary air amount control valve in accordance with the increased or decreased control value. In an auxiliary air amount control device for an internal combustion engine, the output shaft of the engine and the input shaft of the transmission are directly connected, and the auxiliary equipment load changes from an operating state to a non-operating state or vice versa. An auxiliary air amount control device for an internal combustion engine, comprising: means for making a determination; and means for instructing the predetermined amount to be gradually increased or decreased when the determination is made.