JPH01334A - Throttle valve control device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Object of the Invention (Field of Industrial Application) The present invention relates to a throttle valve control device for a so-called linkless throttle, which opens and closes a throttle valve using a step motor based on the operating state of an internal combustion engine.

(Prior art) A throttle valve control device that opens and closes a so-called linkless throttle uses feedback control using a throttle opening sensor that detects the opening of the throttle valve in order to accurately control the opening of the throttle valve. It is common to carry out (Japanese Patent Laid-Open No. 60-206949).

However, when a step motor is used as the actuator to drive the throttle valve, the opening degree of the throttle valve can be known by counting and storing the number of pulses of the drive pulse signal given to the step motor. The opening sensor may be omitted due to factors such as economic efficiency and ease of installation. Further, even if the sensor is provided to check the driving state of the throttle valve, there are cases where the detection output cannot be used effectively due to a failure of the throttle opening sensor. Under such circumstances, it is conceivable that the opening degree of the throttle valve may deviate slightly from the desired opening degree. In particular, when the control target is the minimum opening of the throttle valve (usually, it is fully closed), even a slight deviation in the opening has a large effect on the change in intake air volume, and even greater control precision is required. be done.

Therefore, conventional throttle valve control devices do not actively drive the step motor by setting the control target value of the step motor that drives the throttle valve to the minimum opening, but instead use a counter that biases the throttle valve toward a lower opening. Efforts are being made to improve control accuracy in low opening ranges, such as by installing a spring and interrupting excitation of the step motor when the target (direct) is at the minimum opening to ensure that the minimum opening is reached using the restoring force of the spring. (Unexamined Japanese Patent Publication No. 6.1-1
04134).

(Problems to be Solved by the Invention) However, even with the above-mentioned throttle valve control device, it is still not sufficient and has the following problems.

The driving torque near the minimum opening of the throttle valve is extremely unstable and fluctuates greatly due to tar, sludge, clumps, etc. that adhere to the intake pipe.

When the driving torque of the throttle valve reaches a value exceeding the restoring force of the return spring, it is no longer possible to control the opening degree of the throttle valve to the minimum opening degree by the restoring force of the return spring. Therefore, even if the throttle valve is controlled by the conventional throttle valve control faj device, reproducibility in the lowest opening range is poor and it is predicted that changes over time will be large.

Another possible measure is to increase the elastic force of the return spring, but since this large biasing force always acts on the throttle valve, the step motor that drives the throttle valve must be large and generate a large drive torque. An expensive item must be used, and it is impossible to install it in a limited space.

The present invention has been made to solve the above problems, and even if the throttle valve control device does not have a sensor that detects the opening degree of the throttle valve, it also has a sensor that detects the opening degree of the throttle valve. It is an object of the present invention to provide a throttle valve control device that can accurately control the opening degree of a throttle valve even when the correct opening degree cannot be detected due to an abnormality.

Structure of the Invention (Means for Solving the Problems) In order to solve the above problems, the means constructed in the present invention adjust the intake air amount of the internal combustion engine EG, as shown in the basic configuration diagram of FIG. A throttle that outputs an excitation signal to a step motor SM that drives the throttle valve TB to open and close, in accordance with a detection result of an operating state detection means DD that detects an operating state that includes at least an operation amount of an accelerator operation part AR of the internal combustion engine EG. In the valve control device, when the throttle valve TB is driven to the minimum opening degree, minimum opening degree prevention means C1 prevents the driving of the throttle valve TB, and the throttle valve TB is adjusted according to the detection result of the operating state detection means DD. a minimum opening drive detection means C2 for detecting a minimum opening drive state in which the step motor SM is driven to the minimum opening degree; and when the minimum opening drive detection means C2 detects the minimum opening drive state, and a minimum opening excitation means C3 for outputting an excitation signal corresponding to an amount of movement greater than that for driving the throttle valve TB from the current opening to the minimum opening. This is the summary.

(Function) In the throttle valve control device of the present invention, the minimum opening degree prevention means C1 further prevents the throttle valve TB from becoming lower than the minimum opening degree when the throttle valve TB is driven to the minimum opening degree. It is something to do. Further, the minimum opening drive detection means C2 detects the minimum opening drive state in which the throttle valve TB is driven to the minimum opening degree based on the detection result of the operating state detection means DD. That is, a predetermined operating state, such as when the operation amount of the accelerator operation part AR is the lowest or the load on the internal combustion engine EG is the lowest, is detected as the lowest opening drive state. The minimum opening degree excitation means C3 is
It starts operating only when the minimum opening drive detection means C2 detects the minimum opening drive state, and moves the step motor SM by an amount greater than the amount required to drive the throttle valve TB from the current opening to the minimum opening. Outputs an excitation signal corresponding to .

As a result, the throttle valve TB is activated by the minimum opening degree blocking means C1.
When the throttle valve TB contacts the minimum opening inhibiting means C1, a correction occurs in the step motor SM. Therefore, the minimum opening excitation means C
In order to judge whether or not the operation in step 3 has been carried out reliably, a configuration is adopted in which the tax adjustment generated in the step motor SM is detected and an excitation signal is continued to be output to the step motor SM until the tax adjustment is detected. It's okay.

EXAMPLES Hereinafter, in order to explain the present invention more specifically, examples will be given and explained.

(Example) FIG. 2 is a diagram showing the configuration of an engine equipped with a throttle valve control device according to an example. The throttle valve 2 that controls the intake air amount of the engine 1 is installed just before the upstream side of the surge tank 3, and changes the effective area of the intake passage communicating with the air cleaner 4, thereby controlling the downstream intake pipe 5 and intake boat 6. The flow rate of the flowing air is adjusted to increase or decrease. The intake boat 6 is provided with a fuel injection valve 12, and a predetermined amount of fuel is injected and supplied from the injection valve 12 to the intake air metered as described above, thereby generating an air-fuel mixture. The air-fuel mixture generated in the intake boat 6 is sucked into the combustion chamber 9 when the intake valve 8 is opened. On the other hand, the high pressure generated by the igniter 14 is distributed to the spark plugs 18 provided in each cylinder by the distributor 16, and when the spark plugs spark, the air-fuel mixture is ignited, and the piston 2
An engine torque is generated that pushes down 0. The gas after combustion is released by the exhaust valve 22 which is opened in the same amount as the piston 20 rises again.
is discharged through the exhaust pipe 24 and the catalytic converter 26.

The fuel injection valve 12 and the igniter 14 are controlled by an electronic control device 50.
controlled by. In order to obtain the information necessary for this control, there is a pressure sensor 28 for estimating the intake air amount based on the intake pipe pressure in the surge tank 3, an intake temperature sensor 30 attached to the air cleaner 4 to detect the intake air temperature, and a throttle valve 2. A throttle opening sensor 32 is attached to the throttle shaft of the throttle valve 2 and detects the rotation angle of the throttle valve 2.
, an air-fuel ratio sensor 34 that is attached to the exhaust pipe 24 and detects the oxygen concentration in exhaust gas, a water temperature sensor 36 that detects the cooling water temperature of the engine 1, and a rotation angle sensor 3 that is attached to the distributor 20 that distributes the output of the igniter 14.
8, etc., and the detection signal thereof is manually inputted to the electronic control device 50.

Further, the throttle valve 2 of this embodiment is operated by a step motor 40.
This is a so-called linkless throttle driven by the step motor 40, and the step motor 40 is also controlled by the electronic control unit 50. For this control, in addition to the various sensors mentioned above, an accelerator operation signal, which is analog information proportional to the amount of depression of the accelerator pedal 42, is sent from an accelerator sensor 44 attached to the accelerator pedal 42, and the accelerator pedal 42 is operated in any way. The fully closed detection signal that is output when the valve is not closed is manually generated.

As shown in the figure, the electronic control device 50 is mainly composed of a microcomputer, and its internal configuration includes a CPU 52 that executes arithmetic processing, and a human power port 54 that converts each of the above sensor signals into signals that can be processed by the C:PU 52. , a ROM 56 that stores various control programs in advance, a RAM 5B as a temporal storage means, and a step motor 40 for driving the throttle valve 2, a fuel injection valve 12, and an igniter 14 for transmitting control signals from the CPU 52. It is composed of an output port 59 that converts the drive signal into a drive signal, etc.

FIG. 3 is a diagram illustrating a configuration in which a portion of the intake pipe 5 near the throttle valve 2 is cut away. Since the throttle valve 2 is fixed by the rotor 40a and screw 40b of the step motor 40, the effective area of the intake pipe 5 can be adjusted to a desired value by controlling the excitation signal to the step motor 40.

Additionally, an annular throttle opening sensor 32 having a fitting hole is provided.
is integrally attached to the main body of the step motor 40 by fitting the rotor 40a into the fitting hole, and the rotor 40
The rotation angle of a, that is, the rotation angle of the throttle valve 2 is detected. Furthermore, a substantially elliptical rotation blocking piece 2a is provided at the end of the rotor 40a passing through the throttle opening sensor 32.
is installed, and the rotor 40a receives a rotational force in the direction of the arrow by the elastic force of the return spring 2b provided between one end of the rotation prevention piece 2a and the housing of the throttle opening sensor 32, and rotates. The other end of the movement blocking piece 2a is stopped at a position where it comes into contact with a locking piece 2c protruding from the housing of the front door opening sensor 32.

When an excitation signal is manually applied to the step motor 40, the opening 1-ta 40a rotates in the direction of arrow B against the elastic force of the return spring 2b, and the opening degree of the throttle valve 2 increases. FIG. 4 is an explanatory diagram showing the correspondence between the number of rotational steps of the step motor 40 and the opening degree of the throttle valve 2. As shown in the figure, the throttle valve 2 is fully closed when the rotor 40a is not driven to rotate without manually applying an excitation signal to the step motor 40 (the state shown in FIG. 3), and the step motor 40 is driven in 256 steps. At this time, the throttle valve 2 becomes fully open.

In the engine system configured as described above, the throttle valve 2 is connected to the throttle valve 2 stored in the ROM 56.
By appropriately executing the valve control program by the CPU 52, the drive is controlled as follows. FIG. 5 is a flowchart of the throttle valve control program, and the drive control of the throttle valve 2 will be explained below in accordance with this flowchart.

The CPU 52 reads out the throttle valve control program stored in the ROM 56 every time the built-in timer observes the elapse of 10 mSec, and starts processing. When the process is started, first, the detection signal of the accelerator sensor 44 is read (step 100), and the opening degree of the throttle valve 2 desired by the driver of the engine 1 is detected.

Next, the operating state of the engine 1 is read from the detection signals of the air-fuel ratio sensor 34, rotation angle sensor 38, etc. (step 11).
0), the operating state of the engine 1 is detected. When the current operating state of the engine 1 and the amount of operation of the accelerator pedal 42 by the driver are determined in this way, the target opening CMD of the throttle valve 2 is calculated based on them (step 120).
). Next, the current opening TA of the throttle valve 2 is read from the detection signal of the throttle opening sensor 32 (step 130), and the detection signal is within the range from the fully closed state to the fully open state of the throttle valve 2. It is determined whether the energization system for the throttle opening sensor 32 is in an oven or short-circuited (step 140). Based on this determination, the throttle opening sensor 3
2 is determined to be operating normally, the target opening CMD and the previous target opening CMD[] which was calculated in the previous routine and stored in the RAM5B, that is, the opening indicating the current throttle opening. An excitation signal to be output to the step motor 40 is created and output based on the degree data (step 150). As a result, the rotor 40a of the stem motor 40 rotates by a rotation angle corresponding to the excitation signal, and the opening degree of the throttle valve 2 is adjusted. After that, the detection signal of the throttle opening sensor 32 is read again in order to judge the rotation status (step 160).
, it is determined whether the actual opening degree TA is within a predetermined opening degree centered on the target opening degree CMD (step 170). If the target opening degree CMD and the actual opening degree TA are within a predetermined opening degree centered on the target opening degree CMD, in step 190, the target opening degree CMD obtained in the current process is set to CM for the next process.
After storing it as D a, the processing of this program ends. If the opening is not within the predetermined opening degree, it is determined that a tax adjustment has occurred in the step motor 40, and predetermined tax adjustment processing (step 1) is performed.
After executing step 80), the program ends. Here, the predetermined tax adjustment processing means, for example, the opening data CM that is stored.
These include initialization of Da (CMDG←0) and notification to the driver.

On the other hand, if it is determined in step 140 that an abnormality has occurred in the throttle opening sensor 32, it is required to control the throttle opening.
A flag PTA is set in order to convey the failure state to other programs, for example, a failure alarm routine (step 200). Next, target opening CMD
is in the fully closed state of "0" (step 210), and only when it is determined that the target opening CMD is "0", the target opening CMD is reset to "-1". After the setting process (step 220) is executed once, an excitation signal necessary for making the opening degree of the throttle valve 2 match the target opening degree CMD is output to the step motor 40 by the same process as step 150 ( Step 230). When the control of the step motor 40, that is, the opening control of the throttle valve 2 is completed in this way, it is determined whether the target opening CMD is set to "-1" (step 240), and the target opening CMD is set to "-1". ”, the program is reset to “0” (step 250), proceeds to step 190, and after executing the process of step 190, ends the program.

According to the throttle valve control device configured and operated as described above, it is clear that the throttle valve 2 is driven as follows.

First, when the throttle opening sensor 32 is operating normally, the opening of the throttle valve 2 controlled by the step motor 40 is sequentially checked and the opening of the throttle valve 2 is adjusted with high precision as in the conventional art.

In addition, if the throttle opening sensor 32 is out of order, the opening of the throttle valve 2 cannot be confirmed based on the detection signal of the sensor, and the throttle valve 2 is adjusted to an opening completely different from the desired opening. It is conceivable that the valve 2 may be moved. However, according to the throttle valve control device of this embodiment, the processes of steps 200 to 250 described above are always executed when the target opening CMD is in the fully closed state and the target opening CMD is rOJ. "-1
” is replaced and driven. With this unique control, the throttle valve 2 is not only forcibly driven to the fully open state, but also receives a large torque that tries to rotate it further, causing the rotor 40a to come into contact with the aforementioned locking piece 2C. A tax adjustment occurs in the step motor 40. Therefore, the throttle valve 2 is reliably driven to the fully closed state with the opening degree "0", the number of steps of the step motor 40 and the throttle opening degree are matched, and the opening degree of the throttle valve 2 and the target opening degree are matched. The deviation from CMD will be eliminated.

Therefore, even if the throttle opening sensor 32 fails, or even if the throttle valve 2 is fully closed and the driving torque increases, the control accuracy is maintained well and the optimum state is maintained. be able to.

In the above embodiment, when controlling the throttle valve 2 to the fully closed state, the target opening degree CMD is set to "-1". It is best to manually apply an excitation signal that causes further rotation even when the stop piece 2c of the 1st system comes into contact, and a negative number smaller than "-1" may be set as the target opening degree CMD. Furthermore, for systems not equipped with the throttle opening sensor 32, the target opening CMD is set to a negative number so that step motor 40 always loses synchronization when driving the throttle valve 2 to the fully open state. It may also be configured to output an excitation signal.

As described in detail with examples above, the present invention has the following effects:
Even if the equipped throttle opening sensor becomes abnormal and cannot detect the correct opening, or even if the throttle opening sensor is not equipped, if the minimum opening drive state is detected, the minimum Since the step motor is given an excitation signal corresponding to a larger amount of movement than the amount required to move the throttle valve to its opening position, the throttle valve is reliably driven to the minimum opening position at which movement is regulated by the minimum opening prevention means. Therefore, even if changes over time or variations occur, the opening degree of the throttle valve is always adjusted based on the minimum opening degree, so that the opening degree of the throttle valve can always be controlled with high precision.

[Brief explanation of drawings]

FIG. 1 is a basic configuration diagram showing the basic configuration of the throttle valve control device of the present invention, FIG. 2 is a configuration diagram of an engine system equipped with the throttle valve control device of the embodiment, and FIG. 3 is a diagram of the throttle valve control device of the embodiment. A configuration diagram of the vicinity of the valve, Figure 4 is an explanatory diagram of the relationship between the number of steps of the step motor and the front torque opening,
FIG. 5 shows a flowchart of a throttle valve control program executed in the same embodiment.

Claims (1)

[Claims] An excitation signal for a step motor that opens and closes a throttle valve that adjusts the amount of intake air of the internal combustion engine, in response to a detection result of an operating state detection means that detects an operating state that includes at least the amount of operation of an accelerator operating section of the internal combustion engine. In the throttle valve control device that outputs a minimum opening degree, when the throttle valve is driven to a minimum opening degree, a minimum opening degree prevention means for preventing the throttle valve from being driven; and a detection result of the operating state detection means, the throttle valve is a minimum opening drive detection means for detecting a minimum opening drive state in which the step motor is driven to the lowest opening; and when the minimum opening drive detection means detects the minimum opening drive state, the current throttle A throttle valve control device comprising: minimum opening excitation means for outputting an excitation signal corresponding to an amount of movement greater than driving the valve from its opening to its minimum opening.