JPH0771307A - Control valve drive device of engine - Google Patents

Abstract

PURPOSE:To prevent control delay of a control valve drive device of engine for controlling a plurality of control valves so as to control the engine. CONSTITUTION:A first electromagnetic valve 6 and a second control valve are placed in parallel to one another to control an engine, and the opening of the first electromagnetic valve 6 is changed linearly while the opening of the second electromagnetic valve 7 is operated either to a full opening or to a full closure. The controlled variable for driving the first and second electromagnetic valves 6, 7 is calculated by a first microcomputer 50 based on the drive condition of an engine 1. The controlled variable calculated by the first microcomputer 50 is transmitted to a second microcomputer for driving the first and second electromagnetic valves 6, 7 through a DMA(Direct Memory Access) communication by means of a data of specific byte length. When the controlled variable of the first and second electromagnetic valves 6, 7 is transmitted through DMA communication, a first electromagnetic valve control data and a second electromagnetic valve control data are included while the data is formed into the specific byte length at which transmission is carried out at one time through DMA communication, by the first microcomputer 50.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine control valve drive device for controlling a plurality of control valves provided to control an engine.

[0002]

2. Description of the Related Art Conventionally, for example, there is a device for controlling the engine speed during idle operation by providing two solenoid valves in parallel on a path bypassing a throttle valve in an engine intake pipe (for example, Japanese Patent Publication No. 63-65820). Issue). That is, this device has one solenoid valve (hereinafter referred to as the first
The solenoid valve is integratedly controlled according to the difference between the target rotation speed and the actual rotation speed of the engine, and when the first solenoid valve reaches the nearly full open position, the other solenoid valve (hereinafter, referred to as the second solenoid valve). ) Is fully opened, whereby it is possible to improve the control accuracy by the integral control and expand the control range of the intake air amount.

By the way, in recent years, in an electronic control unit for engine control, a plurality of microcomputers (hereinafter referred to as "microcomputers") are provided in the electronic control unit due to complicated control contents or diversification of control items. Therefore, there is a tendency to share the arithmetic control processing among the respective microcomputers. For example,
From the relationship with the ROM (Read Only Memory) capacity in the microcomputer or the size of the control program, one of the microcomputers calculates the control amount, and the other microcomputer sends signals to the various drive circuits according to the calculated control amount. It is to output.

Further, in such a device, the control amount calculated by the microcomputer for calculation is stored in the direct memory.
It is transmitted to the driving microcomputer using access (hereinafter referred to as “DMA”) communication.

[0005]

However, in the conventional engine control valve driving device, when the above-mentioned two techniques are adopted, that is, the control is calculated by the microcomputer for calculation, and the control is performed by the DMA communication. When the control is transferred to the driving microcomputer and the first and second solenoid valves are controlled based on the output signal of the driving microcomputer, the following problems occur.

In other words, when the calculation control amount is transferred from the calculation microcomputer to the control microcomputer by DMA communication, D
Since the data that can be sent at one time by MA communication is in units of 2 bytes, if the control amount data for the first solenoid valve reaches a 2-byte length such as 10 bits, the control data for the second solenoid valve cannot be sent at the same time. However, a problem occurs in which the idle speed temporarily fluctuates.

To further explain this point, for example,
At the timing when the first solenoid valve reaches nearly full opening and the second solenoid valve is opened, control data such that the second solenoid valve is closed for the first solenoid valve is sent to the second solenoid valve. On the other hand, it is necessary to send control data such as opening the valve.
However, in DMA communication, as described above, these two control data cannot be sent at the same time. Therefore, if the control data for the first solenoid valve and the control data for the second solenoid valve are transferred in this order, the first solenoid valve closes before the second solenoid valve opens, and the intake air amount rapidly increases during this period. Will decrease and the idle speed will drop sharply. On the other hand, when the control data is transferred in the opposite order, the idle speed is overspeeded and the control is delayed in this way.

Therefore, the present invention has been made to solve such a problem, and in a device for controlling an engine by driving a plurality of control valves, there is a drive delay between at least two control valves. An object of the present invention is to provide a control valve drive device for an engine that can be accurately driven without inviting.

[0009]

In order to solve the above problems, the present invention is provided with a first solenoid valve and a second control valve for controlling the operating state of the engine. The first microcomputer calculates a control amount for driving the first and second electromagnetic valves based on the operating state of the engine. A transfer means is provided for transferring the control amount calculated by the first microcomputer to the second microcomputer by DMA communication with data of a predetermined byte length. In the engine control valve drive device, the second microcomputer outputs a signal for driving the first and second control valves based on the control amount calculated by the first microcomputer. The first microcomputer includes the first solenoid valve control data and the second solenoid valve control data when transferring the calculated control amounts of the first and second solenoid valves by DMA communication, and the DMA communication. To create data of the predetermined byte length that can be transferred at once.

In the data creation of the first microcomputer, the first microcomputer opens the second solenoid valve fully if the opening degree of the first solenoid valve is equal to or more than a predetermined value from the calculated control amount. 2 ”and data of“ 0 ”that fully closes the second control valve if less than a predetermined value.
The second solenoid valve switching data of the value is created and DMA communication is performed with the second solenoid valve control data.

The predetermined value of the opening degree of the first solenoid valve for switching the second solenoid valve may be set to 50%. When the opening degree of the second solenoid valve is fully opened, the opening degree of the first solenoid valve corresponding to the flow rate is subtracted from the opening degree of the first solenoid valve. The opening degree of the first solenoid valve is reduced depending on the battery voltage.

The predetermined value of the control data of the first solenoid valve and the opening degree of the first solenoid valve for switching the second solenoid valve are determined depending on whether the air conditioner is operating or not. , I made it.

[0013]

According to the engine control valve drive device of the present invention,
When the first microcomputer transfers the calculated control amounts of the first and second solenoid valves by DMA communication, the first microcomputer
The solenoid valve control data and the second solenoid valve control data are included, and the first solenoid valve and the second solenoid valve are created by creating the data of the predetermined byte length that can be transferred at one time by DMA communication. There is no control delay during the period, and it has become possible to prevent sudden changes in the idle speed. Specifically, in the data creation of the first microcomputer, the first microcomputer opens the second solenoid valve fully if the opening degree of the first solenoid valve is a predetermined value or more based on the calculated control amount. Binary second solenoid valve switching data consisting of "1" data and "0" data that fully closes the second control valve if less than a predetermined value is created and used as the second solenoid valve control. By performing the DMA communication with the data, the opening data of the second solenoid valve need only be 1 bit, so that it becomes easy to sufficiently include the 2-byte data in the above example.

The predetermined value of the control data of the first solenoid valve and the opening degree of the first solenoid valve for switching the second solenoid valve are determined depending on whether the air conditioner is operating or not. By creating it, it is possible to cope with a sudden change in load.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing the overall configuration of a control valve drive device for an engine according to an embodiment of the present invention. In FIG. 1, an engine 1 has a plurality of cylinders, an intake pipe 2 supplies intake air to the engine 1, and an intake branch pipe is provided to distribute the intake air to each cylinder. Engine 1 in intake pipe 2
A throttle valve 30 for controlling the amount of intake air supplied to the throttle valve 30 is provided, and the throttle valve 30 further includes an idle switch 2 for detecting that the throttle valve 30 is fully closed.
5 are provided. Further, the intake branch pipe 3 is provided with an injector 40 that supplies fuel to the engine 1.

The intake pipe 2 is provided with a first bypass passage 4 and a second bypass passage 5 that bypass the throttle 30. Each bypass passage has an intake air amount (auxiliary air amount) in the passage. For controlling the first and second solenoid valves 6,
7 is provided. Here, the first solenoid valve 6 is a duty control valve that linearly changes its opening degree in the range of 0 to 100% according to a duty pulse A from an electronic valve control device described later, and the second solenoid valve 7 Is an on / off valve that is controlled to be either fully open or fully closed according to a control signal B from the electronic control unit.

On the other hand, the engine 1 is provided with an igniter 20 for outputting a high voltage required for ignition, and a distributor 22 for distributing and supplying the high voltage generated by the ignition device 20 to the ignition plugs 21 of the respective cylinders. . Inside the distributor 22, a rotation angle sensor 23 that generates a rotation angle signal according to the rotation of the distributor 22 is provided.

The electronic control unit 8 (ECU) inputs signals from various sensors to be described later, calculates a control amount for controlling the engine 1, a waveform shaping circuit 9 and an A / D converter 10.
(Analog to Digital Converter), input circuit 11, 1
2, first and second microcomputers 50 and 60, DMA communication line 7
0 and output circuits 13 and 14. The waveform shaping circuit 9 shapes the waveform of the output signal of the rotation angle sensor 23, and the signal shaped by the waveform shaping circuit 9 is input to the input circuit 11. A / D converter 10
Is to input a signal from a sensor that outputs an analog signal such as the water temperature sensor 26 or the air flow meter 27, and converts the analog signal into a digital signal. The signal converted into the digital signal is the input circuit 11 and the input circuit 12.
Entered in. On the other hand, the signals from the sensors that output ON / OFF signals such as the idle switch 25 and the air conditioner (hereinafter referred to as “air conditioner”) switch 28 are A /
It is directly input to the input circuit 11 and the input circuit 12 without passing through the D converter 10.

The microcomputer 50 calculates the control amount such as the fuel injection amount and the ignition timing based on the information from the various sensors input to the input circuit 11, and outputs the calculated control amount to the output circuit 13. The microcomputer 50 also calculates a control amount for controlling the first and second solenoid valves, and outputs the calculated control amount to the microcomputer 60 via the DMA communication line 70.
The DMA communication between the microcomputer 50 and the microcomputer 60 will be described in detail later.

The microcomputer 60 performs arithmetic processing for detecting abnormality of the various sensors and the engine itself based on the information from the various sensors input to the input circuit 12. Further, the microcomputer 60 outputs the data for controlling the first and second solenoid valves transferred from the microcomputer 50 to the output circuit 1
Output to 4. The output circuit 13 is the microcomputer 50, 60
A signal for driving the igniter 20, the injector 40, and the like is output based on the control amount calculated in the above, whereby the engine 1 can be controlled with the optimum ignition timing and fuel injection amount according to the operating state. .

Based on the control amount calculated by the microcomputers 50 and 60, the output circuit 14 outputs the duty pulse A for linearly changing the opening of the first electromagnetic valve 6 to the second electromagnetic valve 6 as described above. An on / off signal B for controlling the valve 7 to be fully open or fully closed is output to the valve 7.
Here, the duty pulse A is LSB (Least significan
t bit) is represented by 2 **-10 10-bit data,
The first solenoid valve 6 is fully closed at a duty ratio of 0%, and the first solenoid valve 6 is fully opened at a duty ratio of 100%.

Therefore, in the device of this embodiment, the control output to the first and second solenoid valves 6 and 7 is performed by the microcomputer 60,
Even if the output port of the microcomputer 50 is insufficient, the first and second solenoid valves 6 and 7 can be driven by the control amount calculated by the microcomputer 50. Next, the microcomputer 50 and the microcomputer 6
The DMA communication used for transmitting and receiving data between 0 will be described.

FIG. 2 is a diagram for explaining DMA communication used for data transmission / reception between the microcomputers 50 and 60 of FIG. As shown in FIG. 2, the microcomputers 50 and 60 are connected by the following four lines. That is, the line sends data from the microcomputer 50 to the microcomputer 60 or sends data from the microcomputer 60 to the microcomputer 50 DM
A line is a CLK line for transmitting a clock signal for synchronizing data from the microcomputer 50 to the microcomputer 60, and a line is a signal indicating that the microcomputer 60 is in a receivable state to the microcomputer 50. CTS line for sending a signal indicating that the line is in a receivable state to the microcomputer 60.
It is a line.

Next, the operation of the DMA communication will be described. The DMA communication is started by informing the microcomputer 50 that the microcomputer 60 can receive by the CTS line. When the microcomputer 50 receives the signal on the CTS line, it determines a predetermined RAM (Random Access Memory).
y) The memory content starting from the address is output to the microcomputer 60 through the DMA line in synchronization with the clock signal for a predetermined data length. Then, the microcomputer 60
The data input through the MA line is written in the determined RAM area in the microcomputer 60.

From the RAM in the microcomputer 50 to D
Output to the MA and writing to the RAM in the microcomputer 60 can be performed without the intervention of a program in each microcomputer.
This is performed by hardware by the DMA controller provided in each microcomputer, and the DMA reception side (the microcomputer 6
The byte length that can be written to a predetermined address at once in 0) is 2 bytes.

Data transfer from the microcomputer 60 to the microcomputer 50 is also performed by the same method as in the case of the microcomputer 50. Here, the problem is
As described above, in the DMA communication, it is possible to transfer only the length of 2 bytes from the microcomputer 50 to the microcomputer 60. That is, since the duty ratio data for controlling the first solenoid valve 6 is 10-bit data in this embodiment, the duty ratio data and the second solenoid valve 7 are used.
On / off control data for controlling
It cannot be transferred to 0. Therefore, the apparatus of the embodiment of the present invention is provided with means for solving such a problem, and this point will be described in detail with reference to the flowcharts shown below.

FIG. 3 shows the process for obtaining the duty ratio for controlling the first solenoid valve, and finally determines how to control the first solenoid valve 6 and the second solenoid valve 7 from this duty ratio. 4 is a flowchart showing a process, and FIG.
Is a graph showing the relationship between the duty ratio DCAL and the auxiliary air amount. The arithmetic processing of FIG. 3 is started by the microcomputer 50 every time the base routine is executed.

In FIG. 3, in step 300, each parameter indicating the operating state of the engine is read from the battery voltage and the sensor output signals of the rotation angle sensor 23, the water temperature sensor 26, the idle switch 25, and the air conditioner switch 28 described above. In step 301, it is determined from the above parameters whether or not the feedback control of the idle speed is performed. The determination here is, for example, a region where the foot-back control is performed when the idle switch 25 is turned on and the cooling water temperature satisfies a condition such as a predetermined temperature or higher. When it is determined in step 301 that the area is the foot-back control area, step 3
In step 02, the set value DLNT is determined based on the difference between the actual engine speed and the target engine speed.

On the other hand, if it is determined in step 301 that the area is not in the feedback control area, step 302
The process proceeds to step 304 without executing the process of. Step 3
At 03, various correction terms are set based on the setting value DLNT determined at step 302 and the information from the various sensors read at step 300. The various correction terms are the correction term DTH set according to the cooling water temperature.
W, a correction term tDB set according to an applied state of an electric load such as a wiper or a headlight, and a learning value DG for converging an intake air amount that fluctuates due to a change with time of the first control valve.

Here, the processing of step 303 will be further described. In the apparatus of this embodiment, the above-mentioned step 302 is performed.
Various correction terms are set on the basis of the set value DLNT obtained in. Therefore, for example, when obtaining the correction term DTHW, if the difference between the actual engine speed and the target engine speed is different even with the same cooling water temperature, different values of the correction term DTHW are set.

In step 304, it is determined whether or not the air conditioner is currently operating based on the signal from the air conditioner switch 28 read in step 300. If the air conditioner is operating, the process proceeds to step 305, and the air conditioner is operating. If not, go to step 306. Step 305
Then, the correction term DTHW, the correction term tDB, and the learning value DG set in step 303 and the correction term DIAC at the time of operating the air conditioner are added as follows, and the duty for controlling the duty of the first solenoid valve 6 is added. Find the ratio DCAL.

DCAL = DTHW + tDB + DG + DIAC + ... On the other hand, in step 306, the correction term DTHW and the correction term tDB set in step 303 and the correction term DIS when the air conditioner is not operating are added as follows to obtain the duty ratio DCAL. . DCAL = DTHW + tDB + DIS + ... In step 307, the duty ratio DCAL thus obtained is set in a predetermined register (D register). The D register is a 2-byte register.

Further, the duty ratio DCAL obtained in the above-mentioned processing indicates the amount of auxiliary air to the engine 1 according to the operating state. As shown in FIG. 4, the duty ratio DCAL and the amount of auxiliary air are Has a linear relationship in which the auxiliary air amount increases as the duty ratio DCAL increases. In FIG. 3, the following step 308
Then, the duty ratio DVS corresponding to the flow rate when the second solenoid valve 7 is opened is set according to the battery voltage. The DBSV is experimentally obtained in advance and stored in the one-dimensional map according to the battery voltage. Then, in this step, a value corresponding to the battery voltage is read from this one-dimensional map and the duty ratio DVSV is set.

Since the valve operation becomes slower as the battery voltage decreases, the duty ratio DVSV is set to increase as the battery voltage decreases. In step 309, the lower limit duty ratio DOPMN of the first solenoid valve 6 is obtained. The lower limit duty ratio D
OPMN is the lower limit value of the duty ratio that controls the first solenoid valve 6, and does not stall even when both the throttle valve 30 and the second solenoid valve 7 are fully closed, and is the lowest first solenoid that operates the engine. It is the opening degree of the valve 6. Since the value of the duty ratio DVSV increases as the battery voltage decreases, the value of the lower limit duty ratio DOPMN is set to decrease as the battery voltage decreases.

In step 310, the air conditioner switch 26
It is determined whether the air conditioner is currently operating or not from the output signal of step S31. If the air conditioner is operating, step 31
1, and if the air conditioner is not operating, proceed to step 312. In step 311, the value of the duty ratio DCAL set in the above-described processing is checked, and the duty ratio DAL
It is determined whether CAL is 50% or more. And
If the duty ratio DCAL is 50% or more, the process for opening the second solenoid valve 7 after step 316 is executed, and if the duty ratio DCAL is less than 50%, the second solenoid valve 7 after step 314 is opened. The process for closing the valve is executed.

Here, the reason for executing this discrimination processing will be described with reference to FIG. In FIG. 4, the point where the duty ratio DCAL = 50% is a value sufficiently larger than the duty ratio DVSV corresponding to the flow rate when the second solenoid valve 7 is opened. In other words, the duty ratio DCAL = 50
%, The amount of auxiliary air supplied to the engine 1 is the second
This means that the flow rate is sufficiently larger than the flow rate when the solenoid valve 7 is opened. Therefore, the duty ratio DCA
When L becomes 50% or more, even if the second solenoid valve 7 is opened, it is possible to supply the optimum amount of auxiliary air to the engine 1 according to the operating state. By determining whether the ratio DCAL is 50% or more, it is determined whether the second solenoid valve 7 is opened or closed.

Returning to FIG. 3, on the other hand, in step 312,
It is determined whether or not it was determined that the air conditioner was operating at the previous execution of this routine. If the air conditioner was operating previously, the process proceeds to step 313, and if the air conditioner was not operating previously, the process proceeds to step 311. In step 313, the duty ratio DCAL is the sum of the duty ratio DVSV and the lower limit duty ratio DOPMN (DVSV + DOPM).
N) It is determined whether it is smaller than. Then, if the lower limit duty ratio DOPMN is smaller than the addition value (DVSV + DOPMN), the processing for closing the second solenoid valve 7 in step 314 and thereafter is executed, and if it is not smaller, the second solenoid valve 7 in step 316 and later is executed. Perform the process for opening the valve.

Here, the reason for executing this discrimination processing will be described with reference to FIG. In FIG. 4, the point where the duty ratio DCAL = added value (DVSV + DOPMN) is that the amount of auxiliary air supplied to the engine 1 is the second solenoid valve 7.
It is equal to the flow rate when the valve is opened. Therefore, the duty ratio DCAL is equal to the added value (DVSV
When it becomes smaller than + DOPMN), it is not possible to supply the optimum amount of auxiliary air to the engine 1 according to the operating state with the second solenoid valve 7 open. Therefore, in the present embodiment, whether the second solenoid valve 7 is opened by determining whether the duty ratio DCAL is 50% or more,
They are deciding whether to close the valve.

Returning to FIG. 3, since it is determined in step 314 that the second solenoid valve 7 is closed by the above-mentioned determination processing, the XACVSV flag is reset (XACVSV ← 0) to close the second solenoid valve, and the step is performed. At 315, the value of the duty ratio DCAL is directly set as the control duty ratio DOP for controlling the first solenoid valve 6, and the present routine is ended.

On the other hand, in step 316, it is determined by the above-mentioned determination process that the second solenoid valve 7 is opened. Therefore, the XACVSV flag is set (XAVSV flag to open the second solenoid valve 7).
CVSV ← 1), and in step 317 the duty ratio D
Value obtained by subtracting the duty ratio DVSV from CAL (DCAL
-DVSV) is set as the control duty ratio DOP, and this routine ends. That is, in step 317, the second solenoid valve 7 is opened, so the control duty ratio DOP is set so that the first solenoid valve 6 is closed by the duty ratio DVSV corresponding to the flow rate of the second solenoid valve 7 opened and flowing. It is set. Next, the process of the flowchart of FIG. 3 described above will be described in more detail with reference to FIG.

FIG. 5 is a time chart for explaining the flowchart of FIG. 3 in more detail. 5, (A) shows the air conditioner switch 26, (B) shows the duty ratio DCAL, (C) shows the control duty ratio DOP, and (D) shows the change of the XACVSV flag. Figure 5
At time T1, the air conditioner is inactive,
Since the air conditioner is not in operation at the time of the previous execution of the process (T0) of FIG.
The sequence proceeds from 0 → step 312 → step 311. In step 311, it is determined whether the duty ratio DCAL is 50% or more. At this timing, the duty ratio DCAL <5
Since it is 0%, the process proceeds to steps 314 and 315, and XA
The CVSV flag holds the reset state, and the control duty ratio DOP becomes the duty DCAL.

At time T2, since the air conditioner is in the operating state, an affirmative decision is made in step 310 and the routine proceeds to step 311, but also at this timing the duty ratio DCA
Since L <50%, the XACVSV flag holds the reset state and the control duty ratio DOP becomes the duty ratio DCAL. At time T3, since the air conditioner is in the operating state and the duty ratio DCAL> 50%, affirmative determination is made in steps 310 and 311 and the process proceeds to steps 316 and 317, the XACVSV flag is set, and the control duty ratio is set. DOP is a value obtained by subtracting the duty ratio DVSV from the duty ratio DCAL (DC
AL-DVSV).

Then, from time T3 to time T4, determination processing is performed along the same route as time T3, and steps 316 and 3 are performed.
In step 17, the XACVSV flag holds the set state, and the control duty ratio DOP is the duty ratio DC.
A value obtained by subtracting the duty ratio DVSV from AL (DCAL-
DVSV). At time T4, the air conditioner is not in operation, and the air conditioner was in operation at the time of executing the process of FIG. 3 last time, so the process proceeds to step 309 → step 310 → step 312 → step 313, and the duty ratio DCAL is added at step 313 Value (DVSV + DOPM
N) is compared. Then, at time T4, as shown in FIG.
Since DCAL <(DVSV + DOPMN), as shown in FIG.
4, the XACVSV flag is reset and the control duty DOP is set to the duty ratio DCA.
It becomes L.

FIG. 6 is a flow chart showing a process of writing the control data of the first and second solenoid valves 6 and 7 obtained by the process of the flow chart shown in FIG. 3 in a predetermined transfer area for transferring to the microcomputer 60. , Is started each time the base routine is executed. In this embodiment, the process of writing in the transfer area is executed by a routine different from the process of calculating the control amounts of the first solenoid valve 6 and the second solenoid valve 7, but it is shown in FIG. You may perform in the process of a flowchart.

In FIG. 6, in step 600, the control duty ratio DO of the first solenoid valve 6 obtained by the arithmetic processing of FIG.
P, XACV indicating the on / off control state of the second solenoid valve 7
Read the SV flag. In step 601, the control duty ratio DOP is stored in the D register. Step 602
Then, it is determined whether or not the XACVSV flag is 1, and XACV
If the SV flag is 1, the process proceeds to step 603 and XA
If the CVSV flag is not 1, the process proceeds to step 604.

At step 603, in order to turn on (open) the second solenoid valve 7, the most significant bit (MS
Set B) to 1. On the other hand, in step 604, the most significant bit (MSB) of the D register is set to 0 in order to turn off (open) the second solenoid valve 7. In step 604, the 2-byte control data of the first and second solenoid valves 6 and 7 created by the above-described processing is written in a predetermined transfer area for DMA communication with the microcomputer 60, and this routine is ended.

FIG. 7 is a diagram showing the inside of the D register.
As described above, the second solenoid valve 7 is installed in the most significant bit (MSB).
Is assigned to control the ON / OFF of the solenoid valve, and 0-bit to 9-bit is assigned to 10-bit duty ratio data for controlling the first solenoid valve 6. Therefore, by executing the above-described processing, the control data of the first and second solenoid valves 6 and 7 can be made into one control data having a 2-byte length.

FIG. 8 shows the data written in a predetermined transfer area in the flow chart of FIG.
It is a flowchart which shows the process made to transfer to 0. Figure 8
In step 801, a reception request signal from the microcomputer 60 is read. In step 802, the microcomputer 50
The data stored in the internal transfer area is serially transferred to the microcomputer 60 every 2 bytes.

FIG. 9 is a flowchart showing a process of outputting a control signal to the first solenoid valve 6 and the second solenoid valve 7 based on the data transferred from the microcomputer 50 by DMA communication. This process is performed by the microcomputer 60. Is activated at a predetermined timing (for example, every 4 ms). In FIG. 9, step 90
At 0, the microcomputer 5 starts from the predetermined receiving area in the microcomputer 60.
Read the transfer data from 0.

In step 901, the read data is stored in the D register. In step 902, the transfer data is further stored in the X register. In step 903, the data in the D register is shifted to the left by 1 bit. In step 904, the data in the D register is shifted to the right by 1 bit. By executing the processing of steps 903 and 904, the most significant bit of the D register becomes 0, and the data in the D register is the 10-bit first solenoid valve 6
It becomes the duty ratio data for controlling the.

In step 905, it is determined whether the data in the D register is 0, that is, whether the duty ratio for controlling the first solenoid valve 6 is 0. If it is not 0, the process proceeds to step 906. In step 906, the DMA fail flag is checked to determine whether the current DMA communication has been performed correctly. It should be noted that this DMA fail flag is set by another process (not shown), for example, all data (64
(Byte) is not all transferred, or when the transferred data has a value that cannot be actually taken, it is set as a communication error.

If it is determined in step 906 that the DMA communication is normal, the process proceeds to step 907.
The data in the D register is set in the output register for controlling the first solenoid valve 6, and the process proceeds to step 908. On the other hand, if it is determined in step 905 that the data in the D register is 0, the process of step 907 is not executed and the process proceeds to step 908. If it is determined in step 906 that the DMA communication is abnormal, the subsequent processing is not executed and this routine is ended.

In step 908, X in step 902 is set.
The data stored in the register is stored again in the D register. In step 909, it is determined whether the most significant bit of the data in the D register is 1. If it is determined in step 909 that the most significant bit is 1, the process proceeds to step 910,
The data for opening the second solenoid valve 7 is stored in the second solenoid valve 7
This is set in the control output register and this routine ends. On the other hand, if it is determined in step 909 that the most significant bit is 0, the process proceeds to step 911, in which data for closing the second solenoid valve 7 is set in the output register for controlling the second solenoid valve 7, and this routine is executed. To finish.

FIG. 10 is a time chart showing the fluctuation characteristics of the idle speed when the first solenoid valve 6 and the second solenoid valve 7 are controlled based on the above-mentioned processing. 10, FIG. 10 (A) shows the air conditioner switch 26 state, FIG. 10 (B) shows the change characteristics of the control duty ratio DOP of the first solenoid valve 6, and FIG. 10 (C) the second solenoid valve 7 on / off state. 10 (D) shows the fluctuation characteristics of the idle speed. Further, in FIGS. 10C and 10D, the solid line shows the characteristics when the present embodiment is adopted, and the dotted line shows the characteristics when the conventional device is adopted. In FIG. 10, when the air conditioner is activated and the air conditioner switch 26 is turned on (time point t
1) If the duty ratio DCAL obtained in FIG. 3 increases and DCAL exceeds 50% (time point t2), the second solenoid valve 7 is opened and the second solenoid valve 7 is opened as described above.
The control duty ratio DOP of the first solenoid valve 6 is reduced in order to reduce the amount of auxiliary air by the amount that the valve is opened.

At this time, in the conventional apparatus, the control data of the second solenoid valve 7 was transferred after the control data of the first solenoid valve 6 was transferred because of the byte length that can be sent at one time in the DMA communication. As indicated by the dotted line, there was a control delay between the first solenoid valve 6 and the second solenoid valve 7. Therefore,
In the conventional device, the control duty ratio DO of the first solenoid valve 6 is
Since the intake air amount decreases sharply from when P is small until the second solenoid valve 7 opens, as shown in (X) of FIG.
This caused a sudden change in idle speed.

On the other hand, in the apparatus of the present embodiment, the control data of the first solenoid valve 6 and the second solenoid valve 7, that is, the control duty ratio DOP for the first solenoid valve 6 is reduced,
Since the control data for opening the second electromagnetic valve 7 is transferred from the microcomputer 50 to the microcomputer 60 as one 2-byte data as described above, the first electromagnetic valve 6
And the second solenoid valve 7 can be controlled without causing a delay.

Therefore, by adopting the device of the present embodiment, there is no control delay between the first solenoid valve 6 and the second solenoid valve 7, so that the conventional idle speed fluctuations are prevented. It can be controlled without inviting. Also,
After that, even if the air conditioner is turned off (time point t3) and the second solenoid valve 7 is turned off, the control delay does not occur between the first solenoid valve 6 and the second solenoid valve 7 in the device of this embodiment. ,
Optimal idle speed control can be realized without causing fluctuations in the idle speed (in the future, the intake air amount rapidly increases and the idle speed rapidly increases).

In the present embodiment, an example of the two solenoid valves provided for controlling the idle speed has been described, but the present invention is not limited to this. For example, the fuel evaporative gas generated in the fuel tank The present invention may be applied to other controlled objects for controlling the engine, such as adopting the present invention with respect to two electromagnetic valves provided in the purge pipe for guiding the inside. Further, it can be applied to an EGR valve, a secondary air valve, etc.

In this embodiment, two solenoid valves, one of which is duty ratio controlled and the other of which is on / off controlled, have been described. Of course, both solenoid valves are duty ratio controlled (for example, both solenoid valves are controlled). The present invention may be applied to the control of a solenoid valve whose duty ratio is controlled by 8-bit data), and the present invention is not limited to two solenoid valves, and the present invention is used to control three solenoid valves provided in parallel. For example, the present invention may be adopted to control a plurality of solenoid valves.

[0060]

As described above, according to the present invention, the first microcomputer controls the first solenoid valve when transferring the calculated control amounts of the first and second solenoid valves by DMA communication. The data and the second solenoid valve control data are included, and D
Since the data having the predetermined byte length that can be transferred at one time by MA communication is created, there is no control delay between the first solenoid valve and the second solenoid valve, and the idle speed rapidly changes. Can be prevented. Specifically, in the data creation of the first microcomputer, the first microcomputer fully opens the second solenoid valve if the opening degree of the first solenoid valve is equal to or larger than a predetermined value based on the calculated control amount. 1 ”data and binary 0 solenoid valve switching data that completely closes the 2nd control valve if it is less than a predetermined value. At the same time, since the data for DMA communication is used, the opening data of the second solenoid valve need only be 1 bit, so that it is easy to sufficiently include it in 2 bytes of data.

[Brief description of drawings]

FIG. 1 is a diagram showing an overall configuration of a control valve drive device for an engine according to an embodiment of the present invention.

FIG. 2 is a diagram illustrating DMA communication used for data transmission / reception between microcomputers 50 and 60 of FIG.

FIG. 3 is a process for obtaining a duty ratio for controlling the first solenoid valve 6, and a process for finally determining how to control the first solenoid valve 6 and the second solenoid valve from the duty ratio. It is a flowchart showing.

FIG. 4 is a graph showing a relationship between a duty ratio DCAL and an auxiliary air amount.

FIG. 5 is a time chart for explaining the flowchart of FIG. 3 in more detail.

6 is a flowchart showing a process of writing control data of the first and second solenoid valves 6 and 7 obtained by the process of the flowchart shown in FIG. 3 into a predetermined transfer area for transferring to the microcomputer 60. FIG.

FIG. 7 is a diagram showing the inside of a D register.

8 is a flowchart showing a process of transferring data written in a predetermined transfer area in the flowchart of FIG. 6 to a microcomputer 60 by DMA communication.

FIG. 9 is a flowchart showing a process of outputting a control signal to the first solenoid valve 6 and the second solenoid valve 7 based on the data transferred from the microcomputer 50 by DMA communication.

FIG. 10 is a time chart showing variation characteristics of the idle speed when the first electromagnetic valve 6 and the second electromagnetic valve 7 are controlled based on the above-described processing.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Engine 2 ... Intake pipe 3 ... Intake branch pipe 4, 5 ... Bypass passage 6 ... 1st solenoid valve 7 ... 2nd solenoid valve 8 ... Electronic control device 11, 12 ... Input circuit 13, 14 ... Output circuit 50 , 60 ... Microcomputer 70 ... DMA communication line

Claims (6)

[Claims] 1. A first electromagnetic valve and a second control valve provided for controlling an operating state of an engine, and driving the first and second control valves based on the operating state of the engine. A first microcomputer for calculating a control amount for calculating the control amount, and a transfer unit for transferring the control amount calculated by the first microcomputer to the second microcomputer by DMA communication with data of a predetermined byte length, In the control valve drive device of the engine, the second microcomputer outputs a signal for driving the first and second electromagnetic valves based on the control amount calculated by the first microcomputer, The first calculated by the first microcomputer,
When the control amount of the second solenoid valve is transferred by DMA communication, it includes the first solenoid valve control data and the second solenoid valve control data, and has a predetermined byte length that can be transferred at one time by DMA communication. An engine control valve drive circuit characterized by being created in data. 2. In the data creation of the first microcomputer, the first microcomputer calculates a second value if the opening degree of the first electromagnetic valve is equal to or more than a predetermined value from the calculated control amount.
The binary second solenoid valve switching data consisting of the data "1" for fully opening the solenoid valve and the data "0" for fully closing the second control valve if it is less than a predetermined value is created. 2. The engine control valve drive device according to claim 1, wherein the control valve drive device performs DMA communication with the second solenoid valve control data. 3. The first for switching the second solenoid valve
3. The engine control valve drive device according to claim 2, wherein the predetermined value of the opening degree of the electromagnetic valve is 50%. 4. The opening of the first solenoid valve corresponding to the flow rate when the opening of the second solenoid valve is fully opened is subtracted from the opening of the first solenoid valve. The control valve drive device for an engine according to any one of claims 1, 2, and 3. 5. The control valve drive device for an engine according to claim 4, wherein the opening degree of the first solenoid valve is reduced depending on a battery voltage. 6. The control data of the first solenoid valve and the predetermined value of the opening degree of the first solenoid valve for switching the second solenoid valve depend on whether or not the air conditioner is operating. do it,
The control valve drive device for an engine according to claim 1, which is created.