JPH0381534A - Motor driven throttle device - Google Patents

Abstract

PURPOSE:To prevent runaway at a failure of a throttle valve by respectively communicating introducing pipes and intake pipes having different length to two separated chambers of a surge tank, providing throttle valves drivingly controlled with motors in respective introducing pipes, and providing variable intake valves in respective intake pipes. CONSTITUTION:For example, when a throttle valve 16 is fully closed and uncontrollable, a shutter valve 13 is opened and intake is controlled with a normal side throttle valve 17. Variable intake valves 20, 21 are similarly operated at normal condition. As a result of this, continuance of operation in insured. Meanwhile, when the throttle valve 16 is fixed in opening condition due to bite-in of a foreign matter and the like, the shutter valve 13 and the variable intake valve 20 on the trouble side arc closed, the variable intake valve 21 on the normal side is opened, and intake is controlled with the normal side throttle valve 17. As a result of this, runaway is prevented and simultaneously operation is continued.

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. During this time, for example, when the auto cruise system is operating, the opening of the throttle valve is fully automatically adjusted to maintain the vehicle speed at the set value, regardless of the load condition such as when climbing a hill, or when the automatic mechanical transmission is activated. When disengaging the clutch,
The throttle valve can be easily closed regardless of the amount of pedal depression.

<Problem W to be Solved by the Invention> In a DBW type throttle device, there is a possibility that the throttle opening cannot be controlled due to a failure in its control system including the motor.

In this case, there is a method of attaching a return spring to the throttle valve that biases it in the closing direction, and in the event of a failure, the throttle valve is always kept in a fully closed state by the force of this spring. There is a problem that it becomes impossible. Furthermore, if the throttle valve becomes fixed in the open state due to foreign matter getting caught in the event of a failure, there is a risk that the engine will run out of control.

On the other hand, adding a new fail-safe device to solve the above-mentioned drawbacks has the disadvantage of increasing costs.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide an engine throttle device that can avoid runaway or inoperability in the event of a failure without increasing costs.

Means for Solving the Problems> A throttle device according to the present invention for achieving the above-mentioned object has two intake pipes of different lengths, and the opening and closing of these intake pipes is controlled by a variable intake valve. In the engine to be switched, a surge tank having two isolated chambers;
2 which communicates with the two chambers and introduces intake air into the two chambers;
two inlet pipes, two throttle valves that respectively open and close the inlet pipes and whose opening degree is separately controlled by a motor; and two throttle valves of different lengths that communicate with the two chambers and supply intake air to the engine combustion chamber. two intake pipes,
The present invention is characterized by comprising two variable intake valves that respectively open and close the intake pipes.

Further, a shutter valve may be provided to communicate with and shut off the two isolated chambers of the surge tank.

Function> During normal operation, in the low speed range, the variable intake valve in the short intake pipe is closed and the variable intake valve in the long intake pipe is opened to take in air, while in the high speed range, the variable intake valve in the short intake pipe is opened to take in air. I do. As a result, a good inertial supercharging effect can be obtained in both the low speed range and the high speed range.

If the control system of any throttle valve malfunctions,
Open the variable intake valve on the normal intake pipe and control intake with the normal throttle valve. Here, if a failure occurs while the throttle valve is open, the variable intake valve of that intake pipe is closed.

On the other hand, when a shutter valve is provided that communicates and shuts off the two chambers of the surge tank, a resonance supercharging effect can be obtained by closing the valve in the low speed range and opening it in the high speed range to allow the two chambers to communicate.

Embodiment Hereinafter, an embodiment of the present invention will be specifically described with reference to the drawings.

FIG. 1 is a cross-sectional view of the configuration of an engine throttle device according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view of a driving portion of the throttle valve.

As shown in FIG. 1, a surge tank 11 installed in the intake system of an engine is internally separated into two chambers, an A chamber and a B chamber, by a partition wall 12.

The partition wall 12 is provided with an opening that communicates the two chambers, and a shutter valve 13 is attached to the opening, and the two chambers are communicated with each other or shut off by opening and closing the shutter valve 13.

Introductory pipes 14 and 15 are connected to the surge tank 11 and communicate with chambers A and B, respectively.
Intake air is introduced into the surge tank 11 through step 4.15. Throttle valves 16 and 17 are attached to these introduction pipes 14 and 15, respectively.
The amount of air flowing into each introduction pipe 14, 15 is controlled by the opening degree of the pipes 6, 17.

In addition, intake pipes 18 and 19 are connected to the surge tank 11 on the downstream side in the air flow direction, and communicate with chambers A and B, respectively, and these intake pipes 18 and 19 are connected to an engine combustion chamber (not shown) via a tube. Intake air is supplied. These intake pipes 18, 19 have different lengths, and the intake pipe 18 is relatively short for high-speed use, while the intake pipe 19 is bypassed and is relatively long for low-speed use. Variable intake valves 20.21 are attached to each of the intake pipes 18 and 19, and opening and closing of these variable intake valves 20.21 allows the respective intake pipes 18.19 to be opened or closed.

Next, the throttle valves 16 and 17 will be explained, but since they have the same configuration, one drawing will be explained. As shown in FIG. 2, a throttle valve 16 (17) is rotatably attached in the middle of the introduction pipe 14 (15), and the degree of opening is changed depending on the rotational angular position of the throttle valve 16 (17). A throttle position sensor 24 (25) is attached to one end of the rotating shaft 22 (2B) of the throttle valve 16 (17) to detect its opening, while a servo fixed to a frame (not shown) is attached to the other end. The drive shaft of the motor 26 (27) is attached. Further, a return spring 28 (29), which is a torsion coil spring, is wound around the rotating shaft 22 (23), and the throttle valve 16 (1
7) is energized to be in a fully closed state.

In other words, the throttle valve 16 (17) opens when the servo motor 26 (27) applies driving force against the spring force of the return spring 28 (29), and when the servo motor 26 (27) does not operate, the throttle valve 16 (17) opens. It becomes a closed state.

On the other hand, while throttle valves 1B and 17 require strange opening settings, shutter valve 13. The variable intake valves 20, 21 only need to be able to achieve two states, fully open and fully closed, and their opening/closing drive device (not shown) may be simple. For example, a diaphragm vacuum actuator using negative pressure of intake air can be used at low cost.

In such a configuration, during low speed operation, as shown in Fig. 3(a)
As shown, the variable intake valve 20 of the high-speed intake pipe 18
Close the variable intake valve 21 of the low-speed intake pipe 19, and open the low-speed intake pipe 19t! Inhale using the As a result, in the low speed range, the intake passage area is small and the passage length is long, so that the generated torque can be improved by the inertial supercharging effect.

Also, during high-speed operation, as shown in FIG. 3(b), the variable intake valves 20.1 of the high-speed and low-speed intake pipes 18.19.
21 are opened together, and inhalation is performed through both tracheas 18 and 19. As a result, the area of the intake passage is expanded in the high-speed range, and the inertial supercharging area is also moved to the high-speed range side, making it possible to improve the generated torque. still,
In this case, the variable intake valve of the low-speed intake pipe 19 is closed, and the high-speed intake pipe 1st! It is also possible to use

On the other hand, when aiming for a resonance supercharging effect in chambers A and B of the surge tank 11, in the low speed range, the bulkhead 1
The second shutter valve 13 is closed, while the third shutter valve 13 is closed in the high speed range.
It is better to open the shutter valve 13 as shown in Figure (b).

Next, a case where there is a failure in the control system of either throttle valve 16 or 17 will be described.

First, the control system malfunctions and the return spring 28 or 2
Consider the situation where the throttle valve 16 or 17 is fully closed due to the throttle valve 9.
If the throttle valve is fully closed and uncontrollable, the shutter valve 13 is opened and the normal throttle valve 17 is used to control the intake air, as shown in FIG. 3(c). Further, the variable intake valves 20 and 21 are operated in the same manner as in normal times. As a result,
Continuation of operation is ensured. still. The shutter valve 13 may be closed, and in this case, the variable intake valve 21 of the normal intake pipe 19 is opened.

On the other hand, the throttle valve 16 or 1 may
If the vehicle becomes uncontrollable with 7 open, there is a risk of the vehicle going out of control.

For example, if the throttle valve 16 is fixed in the open state, the shutter valve 13 and the variable intake valve 2 of the intake pipe 18 on the failed side are
0 are closed together, and the variable intake valve 211- of the intake pipe 19 on the normal side is opened to control intake with the normal throttle valve 17.

As a result, it is possible to prevent runaway and at the same time ensure the continuation of operation.

Here, determining whether a failure occurs when the throttle valve is open or closed is determined by, for example, whether the idle switch is ON or not, or whether the output value of the throttle valve is set to a predetermined value. This can be done by checking whether it exceeds the value of .

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 throttle target opening and the throttle position sensor 24, 25
The deviation from the actual measured value is integrated, and if this exceeds a certain value, it is determined that the throttle valves 16 and 17 are not following each other and a failure has occurred. FIG. 4 shows an example of this failure determination flowchart.

In FIG. 4, the target opening degree θ is passed through a -order filter in consideration of the response delay of the valve, and then compared with the measured opening degree θ□. First, in step S12, the target filter value θt is set to θt in the previous calculation.
Based on the t1 value, θ1. Calculate = αθt, +(1-a)θ. Here a is a filter constant and O≦a<
Select within the range of 1. Next, in step S2, the deviation Δθ between this target filter value θt and the actual opening degree θ□ is determined,
In step S3, the deviation Δθ is the allowable error ε. Determine whether it is smaller.

Here, the deviation Δθ is the allowable error ε. If it is smaller, the error accumulation value S is set to a value obtained by subtracting the accumulated error reduction amount ε1 in step S4. On the other hand, if the deviation Δθ is larger than the tolerance c0 in step S3, the error accumulation value S is set to the tolerance 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 16 and 17.

By the way, in the above-mentioned embodiment, since the shutter valve 13 is provided to communicate and cut off the two chambers of the surge tank 11,
By opening and closing it appropriately, it is possible to increase the generated torque in the low speed range and high speed range due to the resonance supercharging effect.
As shown in Figure tc), even if one throttle valve fails while it is closed, it is possible to use the long and short intake pipes 18 and 19. However, in the present invention, this shutter valve 13 is not necessarily provided, and the surge tank 11 is
The room may be left incommunicable.

Furthermore, in the present invention, even if the throttle valve fails with the throttle valve open, the risk of runaway can be avoided, so each motor 26, 2
It is not necessary to provide the return spring 28.29ζ of No.7.

<Effects of the Invention> As described above in detail with reference to one embodiment, according to the present invention, the two isolated chambers of the surge tank are communicated with the inlet pipe and the intake pipe of different lengths, Since each inlet pipe is equipped with a motor-driven throttle valve and each intake pipe is equipped with a variable intake valve, this can be achieved at low cost by using a conventional variable intake valve system, and it also prevents the throttle valve from closing completely. It is possible to prevent runaway and ensure continuation of operation in either case of a full-open failure.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of the configuration of an engine throttle device according to an embodiment of the present invention, FIG. 2 is a cross-sectional view of the throttle valve drive section, FIG.
The figure is a failure determination flowchart. In the drawing, 11 is a surge tank, 12 is a bulkhead, 13 is a shutter valve, 14.15 is an inlet pipe, 16.17 is a throttle valve, 18.19 is a suction gKII! +1 5 20°26°21 is a variable intake valve, and 27 is a servo motor.

Claims (2)

[Claims] (1) In an engine that has two intake pipes of different lengths and in which opening and closing of these intake pipes is switched by a variable intake valve, a surge tank having two isolated chambers and a surge tank that communicates with each of the two chambers and corresponds to the two inlet pipes that introduce intake air into the two chambers; two throttle valves that open and close the inlet pipes and whose opening degree is separately controlled by a motor; 1. A motor-driven throttle device comprising: two intake pipes having different lengths, and two variable intake valves that open and close the intake pipes, respectively. (2) The motor-driven throttle device according to claim (1), further comprising a shutter valve that communicates with and shuts off the two chambers.