JPH02271034A - Fail-safe device of electronically controlled throttle - Google Patents

Abstract

PURPOSE:To run a vehicle safely by discriminating motor stick of a motor driven throttle valve with a control unit, actuating a sub-throttle valve to open/ close, and compensating quantity of air that bypasses the throttle valve. CONSTITUTION:A motor 10 that opens/closes the throttle valve 2 of an engine 1 is controlled by a control unit 30. A sub-throttle valve 16 is provided on the upstream side or the downstream side of the throttle valve 2, and actuated by receiving the suction negative pressure at an actuator 18 through a solenoid valve 20 that receives the open/close signal of the control unit 30. Also, a passage 9 having a control valve 8 and bypasses the throttle valve is provided. When the motor stick discriminating means of the control unit 30 discriminates the stick of the motor 10, the sub-throttle control means opens/closes the sub- throttle valve 16 in response to braking operation. Also, the control valve 8 is actuated by the compensating means to increase the quantity of air of the bypass passage 9. Thus, runaway and operation impossibleness are prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an electronic throttle control in which opening and closing of a throttle valve in a vehicle engine is driven by a motor, and to a fail-safe device when the motor sticks.

[Conventional technology]

In recent years, vehicle engines have tended to be equipped with devices such as cruise control and traction control, and in engines with this type of control device, the mechanical linkage between the throttle valve and the accelerator pedal is separated, and the throttle valve is connected to the motor. It is configured to be opened and closed by. Therefore,
Electric signals from the control unit drive a motor to open and close the throttle valve according to the degree of opening of the accelerator pedal, and in the case of cruise control, the motor is driven according to the vehicle speed to automatically open and close the throttle valve. ing.

However, in the electronic throttle control system, if a harness disconnection, motor stick, etc. occur, the throttle valve is fixed at a fully open, fully open, or intermediate opening position. Therefore, when the throttle is fully closed, it becomes impossible for the vehicle to run and move to a safe place, and when the throttle is fully opened, serious problems such as the vehicle running out of control may occur. Therefore, it is necessary to provide a fail-safe function in advance to ensure safe running of the vehicle in case of such an accident where the throttle valve cannot be controlled.

Therefore, conventionally, regarding the above-mentioned throttle electronic control, for example, Japanese Patent Application Laid-Open No. 61-60331, Japanese Patent Application Laid-Open No. 63-314
There is a prior art of Publication No. 330.

Here, in the former prior art, two throttle valves are provided in the intake system, one throttle valve is mechanically connected to the accelerator pedal, and the other throttle valve is driven by a motor to control slip. It is shown.

Furthermore, in the latter prior art, a sub-throttle valve having a throttle valve driven by an electric motor and a solenoid-type sub-throttle valve fixing device is arranged in the intake passage, and when an abnormality in the throttle valve is detected, the sub-throttle valve is fully opened. It has been shown to be in the state.

[Problem to be solved by the invention]

By the way, in the former prior art mentioned above, the main method is to mechanically open and close the throttle valve using the accelerator pedal, and the electronic control by the motor is auxiliary, so there is no fail-safe against failures in the motor control system. is no longer necessary, but full electronic control of the throttle valve is not required.
)do not have. Therefore, it cannot be applied to control such as cruise control, but the structure becomes complicated due to the two different throttle valve operating mechanisms.

In addition, in the latter prior art, when an abnormality occurs in the electric motor-driven throttle valve, the sub-throttle valve immediately opens fully. In some cases, the vehicle suddenly stops, which is dangerous, and there is also the problem that it is impossible to move the vehicle after it has stopped.

The present invention has been made in view of the above points, and its purpose is to provide an electronic throttle control system that can optimally fail-safe in the event of a failure of the motor stick, etc., in a complete electronic control system for the throttle valve. The purpose is to provide a fail-safe device.

[Means to solve the problem]

In order to achieve the above object, the electronic throttle control fail-safe device of the present invention connects a motor to the throttle valve of the engine intake system, controls the motor, and drives the motor with an output signal from 1 nit to operate the throttle valve. In the fail-safe device, which has a throttle electronic control system that opens and closes, and has a subthrottle valve with an actuator attached to the intake system, the control unit includes a motor stick discrimination means, and the motor stick discrimination means detects the motor stick. A sub-throttle valve control means that opens and closes the sub-throttle valve in response to brake operation when a motor stick of the drive throttle valve is determined, and a correction that corrects the amount of air bypassing the throttle based on a signal from the motor stick determination means. This means that a means has been established.

[For production]

Based on the above configuration, in a system where the throttle valve is completely electronically controlled to open and close by driving a motor based on an electric signal from the control unit, the control unit determines the presence or absence of a motor stick, and when the brake is operated, the sub By closing the throttle valve and reducing engine output, it is easy to prevent the vehicle from running out of control. Also, in this situation,
By securing a predetermined amount of air m that bypasses the throttle valve, it becomes possible to drive the vehicle safely depending on the degree of brake operation.

〔Example〕

Embodiments of the present invention will be described below based on the drawings.

In FIG. 1, reference numeral 1 denotes the main body of a fuel injection type engine. In the intake system, a throttle body 3 having a throttle valve 2 communicates with the engine main body 1 via an intake manifold 4, and the intake system of each cylinder of the engine main body I is connected to the engine main body 1 through an intake manifold 4. An injector 5 is attached to the boat part. In the throttle body 3, a passage 7 having an idle adjustment screw 6 and the like bypassing the throttle valve 2 is provided, and a passage 9 having an idle speed control valve 8 also bypasses the throttle valve 2 and communicates with the passage 7.

On the other hand, a motor 10 is attached to the throttle valve 2 to open and close the throttle valve 2. And as a control system, a water temperature sensor ■1. Engine speed sensor 12° accelerator sensor 13. Throttle opening sensor 14. When a slip control system is added, slip detection means 15 and the like are provided, and these signals are manually processed by the control unit 30. A fuel injection signal is output from the control unit 30 to the injector 5 to control the fuel injection amount, a control signal is output to the idle speed control valve 8 to control the idle speed, and the motor 1
A motor drive signal is output at 0 to open and close the throttle valve 2.

Therefore, as a fail-safe for the throttle electronic control system, a sub-throttle valve 16 is installed upstream or downstream of the throttle valve 2, and this sub-throttle valve I
6, a return spring 17 is attached to the opening direction of the sub-throttle valve 16, and an actuator 18 is attached to the opening direction. The actuator 1B communicates with the intake manifold 4 through a passage 19 having a three-way solenoid valve 20, and drives the actuator 18 with negative suction pressure to activate the sub-throttle valve ■6.
configured to close. Further, a brake sensor 21 for detecting a brake operation is added to the control system, and when a brake operation is detected, a closing signal is output from the control unit 30 to the three-way solenoid valve 20.

In FIG. 2, the failsafe system of the control unit 30 will be described.

First, the control unit 30 is the water temperature sensor 11. It has an idle speed setting means 31 which inputs the water iTw of the engine speed sensor 12 and the engine speed Ne, and determines the valve opening degree of the idle speed control valve 8 according to the water temperature, etc., and this valve opening degree is The correction means 32 is manually operated. This correction means 32 corrects the valve opening to a predetermined value when the motor sticks, and outputs a control signal corresponding to the corrected valve opening to the idle rotation speed control valve 8. Also, the accelerator sensor 13. It has a throttle valve control means 33 which inputs the accelerator operation amount ψ and throttle opening degree θ of the throttle opening sensor 14, searches for the throttle opening degree according to the accelerator operation amount using a map, and generates a motor drive signal according to this. Output to the motor 10. On the other hand, the output of the slip detection means 15 is also input to the throttle valve control means 33, and the motor drive signal is corrected so as to reduce the opening degree of the throttle valve 2 when a slip occurs.

The throttle opening degree and the output of the throttle valve control means 33 are input to a motor stick discrimination means 34, and the motor stick is discriminated based on the state of change in the actual throttle opening value when the motor drive signal is output. The stick signal of the motor stick discrimination means 34 and the brake signal of the brake sensor 21 are transmitted to the sub-throttle valve control means 35 and the correction means 3.
2, the sub-throttle valve control means 35 outputs a close signal to the three-way solenoid valve 20 during brake operation in the case of motor stick, and fully closes the sub-throttle valve 16.

Further, the correction means 32 is configured to increase the valve opening degree of the idle rotation speed control valve 8 in the case of motor stick, and to set the valve opening degree to a predetermined value when the brake is operated.

Next, the operation of the throttle electronic control system with such a configuration is as follows.
This will be described using the flowchart shown in FIG.

First, when the accelerator is operated during engine operation, the accelerator operation amount ψ is detected by the accelerator sensor [3 (step 3100), and the corresponding throttle opening degree θ1 is searched (steps s i, o i ). Further, the actual throttle opening θ is detected by the throttle opening sensor 14 (step 5102), and these are input to the throttle valve control means 33. And target value θ1 and actual value θn
are compared, and if θn>θ1, step S 1.0
5 to 5 IOB, and a drive signal is output to the motor 10 in accordance with the deviation between the two to rotate it to one side, thereby closing the throttle valve 2. In addition, in the case of θn less θ1, step 51
Proceed to step 5107° stog from 05 and motor 1
0 rotates to the other side and throttle valve 2 opens,
In the case of such an opening/closing operation of the throttle valve 2, a flag is set (step 811.0). On the other hand, in the case of θ1-θn, the motor drive signal is not output and the flag is cleared (step 5fG9).

Next, in the case of the opening/closing operation of the throttle valve 2, the process proceeds from step 31 to step 5104 based on the flag, and the motor stick determining means 34 determines whether the actual value is on and the state of change of θn-1. If so, the motor IO is determined to be normal and the flowchart is executed as described above. On the other hand, if there is no change in θn-θn-1,
Although the motor drive signal is being output, the throttle valve 2 is not actually operating, and it is determined that the motor is stuck, and the process proceeds to steps si, tt, and 5L12.

That is, the sub-throttle valve control means 35 immediately outputs a close signal to the three-way solenoid valve 20 when the brake is operated;
The suction negative pressure is introduced into the actuator 18 to fully close the sub-throttle valve 16. On the other hand, the correction means 32 of the idle speed control system adjusts the opening degree of the idle speed control valve 8 to a predetermined value when the motor is stuck. Therefore, the amount of bypass air that bypasses the throttle valve 2 is increased, and a fail-safe is performed so that the engine output is increased compared to the normal idle state. For this reason, no matter what opening degree the throttle valve 2 has, a predetermined amount of intake air can be achieved by fully closing the sub-throttle valve 16 and setting the opening degree of the idle speed control valve 8 to a predetermined value. The vehicle can be driven by operating the brake force appropriately.

In the embodiment of the present invention, the idle rotation speed control valve 8 is used to ensure the amount of intake air during fail-safe operation, but the invention is not limited to this, and a separate control valve may be provided for fail-safe operation. .

Further, the opening degree of the sub-throttle valve 1B and the air bypassing the throttle valve 2 may be variably controlled according to the brake operation m. [Effects of the Invention] As described above, according to the present invention, The complete electronic control system for the throttle valve detects motor stick and controls the engine output using throttle valve bypass means such as the sub-throttle valve or idle speed control, which prevents the vehicle from running out of control and allows safe operation of the brakes. It can be properly fail-safe to run.

Furthermore, it has a fail-safe function in relation to brake operation, resulting in high safety and operability.

Furthermore, since the operating system of the sub-throttle valve is separated from that of the throttle valve, there is no risk of malfunction, and the sub-throttle valve can be operated reliably i).

[Brief explanation of drawings]

Fig. 1 is a block diagram showing an embodiment of a fail-safe device for electronic throttle control of the present invention, Fig. 2 is a block diagram of the control system, and Fig. 3 is a flowchart showing the operation of electronic throttle valve control and fail-safe. It is. 2...Throttle valve, 10...Motor, 18...
Actuator, 20...3-way solenoid valve, 3a...
... Control unit, 32... Correction means, 34... Motor stake determination means, 35... Sub-throttle valve control means -91,i-

Claims (2)

[Claims] (1) A throttle electronic control system that connects a motor to the throttle valve of the engine intake system, drives the motor using an output signal from a control unit to open and close the throttle valve, and includes an actuator in the intake system. In the fail-safe device equipped with a sub-throttle valve, the control unit includes a motor stick determination means,
When the motor stick discrimination means discriminates the motor stick of the motor-driven throttle valve, the sub-throttle valve control means opens and closes the sub-throttle valve in response to brake operation, and the throttle is controlled by a signal from the motor stick discrimination means. A fail-safe device for electronic throttle control, characterized in that it is provided with a correction means for correcting the amount of air to be bypassed. (2) The fail-safe device for electronic throttle control according to claim 1, wherein the opening degree of the sub-throttle valve and the amount of air bypassing the throttle are variably controlled in accordance with the amount of brake operation.