JPH0381532A - Motor-driven throttle valve device - Google Patents

Abstract

PURPOSE:To secure running of operation upon malfunction by providing independent intake passages at every intake valve, and providing a throttle valve which is openly and closely controlled by a motor at the respective intake passages. CONSTITUTION:An intake port 12a for low speed and an intake port 12b for high speed have a common intake hole. Independent intake passages consisting of passages 20, 21, surge tanks 14, 16 and passages 13, 15 is provided. At the respective passages, throttle valves 22, 23 are arranged. In the case that one of control systems of motors 26, 27 are out of order, the throttle valve 22 or 23 at the malfunction side is fully closed by operation of a return spring 28. Thereafter intake control is performed by driving the motor 27 or 26 at a normal side. Consequently, running of operation is secured at the time of malfunction.

Description

Detailed Description of the Invention <Industrial Application Field> The present invention is directed to a so-called D BW (Dr.
ive By Wire) type throttle device.

<Conventional technology> In recent years, gasoline engines installed in passenger cars, etc. have been electronically controlling the fuel supply amount, ignition timing, etc. in order to ensure engine performance such as output while preventing exhaust gas pollution and improving fuel efficiency. There are many things. Conventionally, the throttle valves of carburetors and electronic fuel injection systems were opened and closed in response to the driver's will via a cable directly connected to the accelerator pedal, but auto cruise (constant speed driving) devices With the development of automatic transmissions and mechanical automatic transmissions, a DBW type throttle device has also been developed in which the opening and closing of a throttle valve is electronically controlled using an electric actuator such as a servo motor.

In addition to the amount of depression of the accelerator pedal, this throttle device normally uses a microprocessor to process various data such as clutch engagement status and intake air temperature, and then adjusts the throttle valve to the optimum opening position corresponding to the vehicle's driving conditions at that time. It is decided at the same time. For example, when an auto cruise device is operating, the opening of the throttle valve may be automatically adjusted to maintain the vehicle speed at the set value, regardless of the load condition such as when the vehicle is climbing, or the mechanical automatic transmission may be When disengaging the clutch, the throttle valve can be easily closed regardless of the amount of pedal depression.

By the way, in a DBW type throttle device, if the throttle opening cannot be controlled due to a failure in the control system including the motor, there is a risk of runaway. Therefore, a return spring is attached to the throttle valve, and when the driving force of the motor cannot be obtained, the return spring fully closes the throttle valve.

<Problems to be Solved by the Invention> However, with this device, the throttle valve is automatically closed in the event of a failure, thereby avoiding the risk of runaway, but there is a problem in that the vehicle becomes unable to run.

The present invention has been made in view of the above circumstances, and provides an engine throttle device that can ensure continued operation even in the event of a failure and at the same time provide good engine performance during normal operation. is intended to provide.

Means for Solving the Problems> A throttle device according to the present invention for achieving the above-mentioned object provides an independent intake passage for each intake valve in a multi-valve engine having a plurality of intake valves per cylinder. The present invention is also characterized in that each of the intake passages is provided with a throttle valve that is individually controlled to open and close by a motor.

Function> If the control system for the throttle valve of any intake passage in one cylinder fails, that throttle valve is closed, and operation in that cylinder is maintained by opening and closing the throttle valves of the other intake passages.

During normal operation, the throttle valve of each intake passage can be controlled separately to function as a variable intake system.

Practical example Hereinafter, embodiments of the present invention will be described with reference to the drawings. explain.

FIG. 1 is a configuration diagram of an intake system of an engine according to an embodiment of the present invention, and FIG. 2 is a sectional view of a drive section of the throttle device.

As shown in FIG. 1, the engine 11 of this embodiment is a four-cylinder engine, and each cylinder 12 is provided with two intake boats 12a and 12b, one for low speed and one for high speed, each with an intake valve (not shown). have. Note that the exhaust port is not shown.

A relatively long low-speed passage 13 is connected to each low-speed intake boat 12a, and they communicate with a common surge tank 14. Furthermore, high-speed passages 15 shorter than the low-speed passages 13 are connected to the high-speed intake boats 12b, and these passages communicate with a common surge tank 16.

On the other hand, an air cleaner 17 is provided in the intake hole, and an air flow sensor 19 is provided adjacent to the air cleaner 17 in a common passage 18, and this passage 18 is then branched to open the air cleaner 17.
20 and 21, and they are surge tank 14 respectively.
It communicates with ゜16. And these passages 20.2
A throttle valve 22, 23 is attached to each of the valves 1 to control the flow rate of air flowing therethrough.

That is, the low-speed intake boat 12a and the high-speed intake boat 12b have the same intake hole, but the passage 20. Surge tank 142 passage 13 and h passage 21. surge tank 16
It has mutually independent intake passages each made up of two wlIs 115, and each intake passage is provided with a throttle valve 22, 23, respectively.

Next, the throttle valves 22 and 23 will be explained, but since they have the same configuration, they will be explained with reference to one drawing. As shown in FIG. 2, a throttle valve 22 (23) is rotatably attached in the middle of the throttle valve 20 (21), and the degree of opening is changed depending on the rotational angular position of the throttle valve 22 (23). A throttle position sensor 25 is attached to one end of the rotation shaft 24 of the throttle valve 22 (2B) to detect its opening, while a drive shaft of a servo motor 26 (27) fixed to a frame (not shown) is attached to the other end. is installed. Further, a return spring 28, which is a torsion coil spring, is wound around the rotating shaft 24, and the spring 28 biases the throttle valve 22 (23) to a fully closed state. In other words, the throttle valve 22 (23)l, the servo motor 2 resists the spring force of the return spring 28.
B (27) opens by applying a driving force, and is always in a fully closed state when the servo motor 26 (2?) does not operate.

In addition, the installation position of the fuel injector is, for example, the SPI method installed in a common passage @18, each throttle valve 2
2.23, a two-system SP1 system installed upstream of each cylinder 12, a two-system MP1 system installed in the low-speed passage Il@13 and high-speed passage 15 of each cylinder 12, etc. are both possible.

In such a configuration, during low-speed operation, the throttle valve 23 on the high-speed intake passage side is fully closed, and intake control is performed only by opening and closing the throttle valve 22 on the low-speed intake passage side. As a result, during low-speed operation, the intake passage area is small and the passage length is long, so that the generated torque can be improved by fully utilizing the pulsation effect of the intake air in the low-speed range.

On the other hand, during high-speed operation, the throttle valve 23 on the high-speed intake passage side is also opened in addition to the throttle valve 23 for low-speed operation to perform intake control. As a result, during high-speed operation, the intake passage area becomes larger, reducing suction resistance, and the passage length becomes shorter, so the pulsating effect of the intake air can be utilized up to high engine speeds.

On the other hand, the throttle valves 22 and 23 are
The power supply to the motor 26 or 27 is stopped. Then,
The throttle valve 22 or 23 on the failed side is fully closed by the action of the return spring 28, and the intake system on the failed side is closed. Thereafter, the motor 27 or 26 on the normal side is operated to perform intake control and the operation can be continued. Therefore, even if one of the control systems breaks down, the vehicle can continue to run, and at least be able to travel to a repair shop by itself.

Note that the determination as to whether or not the throttle valve control system has failed is performed, for example, as follows. That is, the deviation between the target throttle opening degree and the actual value measured by the throttle position sensor 25 is integrated, and if this exceeds a certain value, it is determined that the throttle valves 22 and 23 are not following the same and a failure has occurred. FIG. 3 shows an example of this failure determination flowchart.

In FIG. 3, the target opening degree θ is passed through a primary filter in consideration of the response delay of the valve, and then compared with the measured opening degree θ□. First, in step S1, the target filter value θt
1 based on θt in the previous calculation, θ, = αθt,
Calculate by +(1-α)θ. Here, α is a filter constant, which is selected in the range O≦α. Next, in step S2, the deviation Δθ between this target filter value θt1 and the measured opening θ is determined, and in step S3, the deviation Δθ is determined by the allowable error ε
. Determine whether it is smaller. Here, if the deviation Δθ is smaller than the allowable error C8, the error accumulation value S is set to a value reduced by the accumulation error reduction amount ε.

On the other hand, in step S3, the deviation Δθ is the allowable error ε. If it is larger, the error accumulation value S is set to the allowable error ε in step S5.

Set the value to the value added.

Thereafter, in step S6, it is determined whether or not the accumulated error value S is greater than the accumulated error limit ε2. If it is, it is determined that there is a failure, and a throttle failure flag is set in step S7. On the other hand, if it is smaller, the flag is reset in step S8.

This failure determination is performed for each throttle valve.

By the way, in the embodiment shown in FIG. 1, one throttle valve 22, 23 is provided on the upstream side of each surge tank 14, 16, but as shown in FIG. 4, a port is provided on the downstream side of the surge tank. It may also be provided as a valve.

FIG. 4 is a configuration diagram of the main parts of the intake system of an engine according to another embodiment of the present invention. In FIG. 4, the same parts or parts having the same functions as those in FIG. A symbol is attached. As shown in FIG. 4, in this embodiment, each low-speed passage 13 and each high-speed passage 15 are provided with throttle valves 22 and 23, respectively.

A plurality of throttle valves 22 provided in each of the low-speed passages 13 are connected to each other by a common drive shaft 29 to operate in conjunction with each other, and are driven to open and close by a servo motor 26 connected to one end of the drive shaft 29. be done. Similarly, the plurality of throttle valves 23 provided in each high-speed passage are connected by a common drive shaft 30.
It is driven to open and close by a servo motor 27 connected to one end of the servo motor 27. In addition, each drive shaft 29, 30 is provided with a throttle valve 22.
．． A return spring (not shown) is attached that biases 23 in the closing direction.

Even in such a configuration, as in the above embodiment, by separately controlling the throttle valves 22 and 23 during normal operation, it is possible to obtain good engine performance from the low speed range to the high speed range. , even if either of the control systems for the motors 26, 27 fails, operation can continue.

<Effects of the Invention> As described above in detail with reference to the embodiments, according to the present invention, in a multi-valve engine having a plurality of intake valves per cylinder, an independent intake passage is provided for each intake valve, and an independent intake passage is provided for each intake valve. Since each intake passage is equipped with a throttle valve that is controlled to open and close separately by a motor, good engine performance can be obtained by separately controlling the amount of intake air flowing through each intake passage during normal operation. Even if a failure occurs in one throttle control system, continuation of operation can be ensured by using the other intake passage.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram of an intake system of an engine according to an embodiment of the present invention, FIG. 2 is a cross-sectional view of the drive section of the throttle device, FIG. 3 is a failure determination flowchart, and FIG. FIG. 2 is a configuration diagram of main parts of an intake system of an engine according to an embodiment of the present invention. In the drawing, 11 is an engine, 12 is a cylinder, 12a is a low-speed intake port, 12b is a high-speed intake port, 13 is a low-speed passage, 14 is a surge tank, 15 is a high-speed passage, 16 is a surge tank, 18. 20 and 21 are passages, 22 and 23 are throttle valves, 25 are throttle position sensors, 26 and 27 are servo motors, and 28 are return springs.

Claims (1)

[Claims] A multi-valve engine having a plurality of intake valves per cylinder, characterized in that an independent intake passage is provided for each intake valve, and each intake passage is provided with a throttle valve that is individually controlled to open and close by a motor. A motor-driven throttle device.