JPH09188166A - Internal combustion engine throttle valve controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a one-valve type electronic control throttle with a mechanical guard which can change motor output and conduct both cruise control and fail safe. SOLUTION: A mechanical guard 21 which drives a throttle valve 12 in an open direction when an accelerator pedal 30 is operated in the opening direction is fitted. The mechanical guard 21 is always energized in a closed direction by a return spring 22 normally, and when the accelerator pedal 30 is returned to the closed direction, the throttle valve 12 is driven in the closed direction by the energizing force. The throttle valve is connected with a motor 18. A throttle electronic controller 25 conducts opening/closing control of the throttle 12 through the motor 18 according to an operational condition. This device is provided with a driving circuit 19 and so on which makes driving force of the motor 18 larger than energization force of the return spring 24 when the constant speed driving control is on and smaller than the energization when the constant speed driving control is off.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a throttle valve control device for an internal combustion engine used in an internal combustion engine, and more particularly to a one-valve electronically controlled throttle with a mechanical guard.

[0002]

2. Description of the Related Art A conventional one-part electronically controlled throttle with a mechanical guard is known, for example, from Japanese Patent Application Laid-Open No. 2-57436. This electronically controlled throttle will be described with reference to the schematic view of FIG. The throttle valve 1 is openably and closably provided in an intake pipe (not shown) of the engine. In FIG. 3, the throttle valve 1 is schematically shown, and when it is rotated in the opening direction, it is represented by moving upward in the drawing, and when it is rotated in the closing direction, it is moved downward in the drawing. Represented by The throttle valve 1 is operatively connected to a step motor 3 provided in an intake pipe via an electromagnetic clutch 2, and is opened and closed by the forward and reverse rotation of the step motor 3. The step motor 3 is controllable by a throttle ECU (throttle electronic control unit) 4 so as to freely rotate forward and backward. The throttle E
The CU 4 is provided with a microcomputer 4a, and by this microcomputer 4a, cruise control (constant speed traveling control), variable non-linear control, TRC control, I
SC control is possible.

A connecting spring 5 is attached to the throttle valve 1.
The mechanical guard 6 is connected via. The mechanical guard 6 is rotatably supported around the same axis as the throttle valve 1. Note that, in FIG. 3, the mechanical guard 6 is schematically shown, and when rotating in the opening direction,
In the figure, it is represented by moving upward, and when rotating in the closing direction, it is represented by moving downward in the figure.
Further, the mechanical guard 6 is connected to the accelerator pedal 7 via a cable 8 and can be operated by depressing the accelerator pedal 7.

Further, one end of a return spring 9 is connected to the mechanical guard 6. The other end of the return spring 9 is attached to the intake pipe and locked to a housing or the like (not shown) that houses the mechanical guard 6. Therefore, when the mechanical guard 6 is operated in the depression direction of the accelerator pedal 7, the mechanical guard 6 operates against the biasing force (elastic force) of the return spring 9. Further, the elastic force T1 of the return spring 9 and the urging force T2 of the connecting spring 5 are
Is T1 >> T2.

In the figure, S1 is a mechanical guard opening sensor,
S2 is a throttle valve opening sensor, which detects each opening and inputs the detection signal to the throttle ECU 4.

In the above electronically controlled throttle, when the electric system goes down, the electromagnetic clutch 2 is deenergized, and the electromagnetic clutch 2 disconnects the step motor 3 from the throttle valve 4. By opening and closing the throttle by operating the pedal 7, retreat traveling is possible and fail-safe can be achieved.

The electromagnetic clutch 2 is prevented from being turned off, for example, because control such as ISC control is performed except when the above-mentioned electric system is down. In cruise control, constant-speed running control is performed by controlling the drive of the step motor 3 by the throttle ECU 4 and adjusting the opening of the throttle valve 1 while the electromagnetic clutch 2 is turned on (connected). Then, when a brake operation is performed with a brake pedal (not shown), the control of the step motor 3 is released.

[0008]

However, in the above system, there is a problem that the cruise control and the fail safe cannot both be achieved, as shown in the following (1) and (2).

(1) When the output of the step motor 3 <T1 When the microcomputer of the throttle ECU 4 runs out of control to drive the throttle valve 1 to the open side (upper side in FIG. 3) by the step motor 3, the accelerator pedal 7 If the spring is returned, the elastic force (biasing force) T1 of the return spring 9
Is larger than the output of the step motor 3, the fail safe is established.

On the other hand, however, since the elastic force (biasing force) T1 of the return spring 9 is larger than the output of the step motor 3, it is impossible to control the throttle valve 1 to the open side by the step motor 3 and the cruise. The control cannot be controlled.

(2) When the output of the step motor 3> T1 In this case, since the elastic force (urging force) T1 of the return spring 9 is smaller than the output of the step motor 3, the throttle valve 1 of the step motor 3 is operated. Control to the open side is possible and cruise control is possible.

However, when the microcomputer of the throttle ECU 4 runs out of control and drives the throttle valve 1 to the open side (upper side in FIG. 3) by the step motor 3, the output of the step motor 3 is output even if the accelerator pedal 7 is released. Since it is larger than the elastic force T1 of the return spring 9, the throttle valve 1 is driven to the open side, and failsafe is not established.

The present invention has been made in view of the above-mentioned circumstances, and an object thereof is to change the output of a motor to achieve both cruise control and fail-safe, a one-valve electronic control throttle with a mechanical guard. To provide.

[0014]

In order to achieve the above object, in the invention of claim 1, a mechanical guard is connected to the accelerator pedal and drives the throttle valve in the opening direction when the accelerator pedal is operated in the opening direction. , A biasing means for constantly biasing the mechanical guard in the closing direction and driving the throttle valve in the closing direction via the mechanical guard when the accelerator pedal is returned in the counter-opening direction, and a drive for driving the throttle valve to open and close. In a throttle valve control device for an internal combustion engine, which includes means for controlling the opening and closing of a throttle valve via the drive means in accordance with an operating state, the urging means is provided when the driving force of the drive means is controlled at a constant speed. Of the throttle valve for an internal combustion engine having a driving force changing means for making the driving force changer greater than the biasing force of It has as its gist.

According to a second aspect of the present invention, in the first aspect, a constant speed traveling stopping means for outputting a stop command signal is provided, and the control means has a constant speed traveling control function to control the driving means, and By the stop command signal of the constant speed control stop means,
In order to stop the constant speed traveling control, the driving force changing means makes the driving force of the driving means smaller than the urging force of the urging means based on the stop command signal of the constant speed traveling stopping means. The gist is a throttle valve control device for an internal combustion engine.

According to the structure of the invention of claim 1, in the normal case, that is, when the constant speed traveling control is off, the driving force changing means makes the driving force of the driving means smaller than the urging force of the urging means. doing. As a result, when the accelerator pedal is operated in the opening direction, the throttle valve is driven in the opening direction via the mechanical guard. Further, the control means opens and closes the throttle valve via the drive means in accordance with the operating state. During this control, if the driving means is running out of control, the urging force of the urging means is larger than the driving force of the driving means when the accelerator pedal is returned. The mechanical guard drives the throttle valve in the closing direction against. Therefore, fail safe is established.

On the other hand, during constant speed traveling control, the driving force changing means makes the driving force of the driving means larger than the urging force of the urging means. As a result, the drive means is controlled to run at a constant speed to open and close the throttle valve.

According to a second aspect of the invention, the control means has a constant speed traveling control function to control the drive means. Then, the constant speed traveling control is stopped by the stop command signal of the constant speed control stopping means. On the other hand, the driving force changing means makes the driving force of the driving means smaller than the urging force of the urging means based on the stop command signal of the constant speed traveling stopping means.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment in which a one-valve throttle control device with a mechanical guard according to the present invention is embodied in a gasoline engine will be described below with reference to FIGS. 1 and 2.

FIG. 1 is a schematic configuration diagram of a throttle valve control device in this embodiment. In FIG. 1, in the intake passage 10a of the throttle body 10. Throttle valve 1
2 is incorporated so as to be rotatable about its axis via the throttle shaft 14. This throttle valve 1
2 is the intake passage 1 of the throttle body 10
0a is opened and closed to control the intake of the engine. An output shaft of a motor 18 as a driving means is connected to one end portion (the left end portion in the drawing) of the throttle shaft 14 outside the throttle body 10 via an electromagnetic clutch 16. The driving force of the motor 18 is supplied to the throttle valve 12 via the electromagnetic clutch 16.
Is transmitted to

The electromagnetic clutch 16 connects (turns on) the motor 18 and the throttle valve 12 so that torque can be transmitted by energizing a clutch power supply circuit 17 which uses a battery B as a power source, and deenergizes the clutch power supply circuit 17 to turn the electromagnetic power on. It is configured to disconnect (turn off) the connection.

The motor 18 is a stepping motor. This stepping motor includes a drive circuit 19 including a logic circuit that determines the excitation order of the motor windings and a power control circuit that supplies a current to the motor windings. In order to change the voltage applied from the battery B to the power control circuit, a circuit including a switch SW and a circuit including a resistor R are connected in parallel to the battery B. The switch SW is composed of a switching transistor or the like, and is turned on by a first switching signal input from a cruise control determination circuit 27 or a cruise cancel switch 29 described later to drive the motor 18 at a high voltage. Further, the switch SW is turned off by the second switching signal from the cruise control determination circuit 27 to drive the motor 18 at a low voltage.

When the switch SW is turned on, a voltage higher than the rated voltage of the stepping motor is applied from the battery B to the power control circuit so that the motor 18 can obtain a high torque output (driving force). Is configured. When the switch SW is turned off, a voltage lower than the rated voltage of the stepping motor is applied from the battery B to the power control circuit, so that the motor 18 is configured to obtain a low torque output (driving force). There is.

A driving force changing means is constituted by the drive circuit 19, the circuit including the switch SW and the resistor R.
At the other end (the right end in FIG. 1) of the throttle shaft 14, a bearing 2 is provided outside the throttle body 10.
It is rotatably supported at 0. A mechanical guard 21 is rotatably attached to the other end of the throttle shaft 14 between the throttle body 10 and the bearing 20 and is immovable in the axial direction of the throttle shaft 14. Although not shown in FIG. 1, the stopper 21a shown in FIG. 2 is for restricting the rotation amount of the mechanical guard 21 in the closing direction. The mechanical guard 21 is formed in a disc shape. A connecting spring 23 as connecting means is provided between the mechanical guard 10 and the fixed plate 22 fixed to the throttle shaft 14 on the throttle body 10 side.
Both ends of the connecting spring 23 are fixed to the mechanical guard 21 and the fixed plate 22, respectively. The connecting spring 23 applies a biasing force (torsion force) to the throttle shaft 14 in a closing direction (hereinafter referred to as a closing direction).

Further, in the throttle shaft 14, a return spring 24 as an urging means is interposed between the throttle body 10 and the mechanical guard 21, and both ends of the return spring 24 are fixed to the mechanical guard 21 and the throttle body 10, respectively. There is. The return spring 24 applies a closing direction biasing force (torsion force) to the throttle shaft 14, and the biasing force is sufficient to fully close the throttle valve 12 when the electromagnetic clutch 16 is disengaged. It is set to a great power.
The biasing force T1 of the return spring 24 is set so that T1 >> T2 with respect to the biasing force T2I of the connecting spring 23. In addition, return spring 2
The urging force T1 of No. 4 is set to be smaller than the high torque output of the motor 18 and larger than the low torque output thereof.

A throttle valve opening sensor S1 is provided at the other end of the throttle shaft 14 to detect the opening of the throttle valve 12 and output a signal corresponding thereto. or,
A gear-like shape is formed on the peripheral portion of the mechanical guard 21. A mechanical guard opening sensor S2 is arranged corresponding to the peripheral portion of the mechanical guard 21, and outputs a pulse signal in response to passage of a tooth on the peripheral portion of the mechanical guard 21.

As is well known, the accelerator pedal 30 can be depressed by using the pedal shaft 31 as a pivot axis. The accelerator pedal 30 is connected to the mechanical guard 21 via a connecting wire 32, and the mechanical guard 21 rotates in the opening direction according to the amount of depression of the accelerator pedal 30.

Next, the electrical construction of the throttle control device will be described with reference to FIG. A throttle electronic control unit (throttle ECU) 25 as a control means is a central processing unit (CPU) 26, a read-only memory (ROM) (not shown) in which a predetermined control program and the like are stored in advance, C
A random access memory (RAM) (not shown) for temporarily storing the calculation result of the PU 26, a cruise control determination circuit 27, and the like are provided. The throttle opening sensor S
1. The mechanical guard opening sensor S2 is connected to the CPU 26 and inputs a detection signal to the CPU 26. The cruise control switch 28 is provided on the steering wheel of a driver's seat (not shown). The cruise control switch 28 is a switch that the driver turns on / off, and the driver runs at a constant speed (also called auto-drive running).
Is turned on when desired. The cruise control switch 28 is electrically connected to the cruise control determination circuit 27. The cruise control determination circuit 27 determines whether or not the cruise control switch 28 is turned on.
Based on the neutral input, the parking input, the brake input, etc., it is determined whether or not the vehicle is in a state in which it is possible to perform an automatic drive traveling, and an automatic drive traveling permission signal or an automatic drive traveling stop signal is input to the CPU 26.

More specifically, the neutral input is a signal input from a neutral switch for detecting a neutral position by a shift lever of a transmission (not shown). The parking input is a signal input from a parking brake switch that detects that a parking brake (not shown) has been operated. Further, the brake input is a signal input from a stop lamp switch that detects that a foot brake (not shown) is depressed.
When all of these three signals are not input and the cruise control switch 28 is on, the automatic drive travel permission signal is input to the CPU 26. When canceling the automatic drive traveling, the automatic drive traveling stop signal is input to the CPU 26 by inputting a signal from any one of the three signals or by turning off the cruise control switch. The neutral switch, the parking brake switch, and the stop lamp switch, which perform the neutral input, the parking input, and the brake input, respectively, constitute a cruise cancel switch 29. Further, when any of the switches constituting the cruise cancel switch 29 is turned on, or when the cruise control switch 28 is turned off, a second switching signal is input from the cruise cancel switch 29 to the switch SW. Circuit is configured.

Therefore, the neutral switch, the parking brake switch, the stop lamp switch and the cruise control switch 28 which constitute the cruise cancel switch 29 constitute a constant speed traveling stopping means. The neutral input signal, the parking input signal, the brake input signal and the off signal of the cruise control switch 28 are used as the stop command signal.

Now, the operation of the throttle valve control device constructed as described above will be described with reference to FIGS. 1 and 2. Note that FIG. 2 is a schematic diagram, and in FIG. 2, the throttle valve 21 and the mechanical guard 21 are schematically shown, and when rotating in the opening direction, they are shown by moving upward in the figure and in the closing direction. In the case of turning to, it is represented by moving downward in the figure. Further, in FIG. 2, the throttle valve 12 can be rotated in the range of “fully open” and “fully closed”, and the range of α is the range of rotation of the throttle valve 12 in ISC control (idle speed control). .

(Accelerator pedal operation during normal operation) When the vehicle is running and cruise control, TRC control, ISC control, variable non-linear control, etc. are not being performed, the electromagnetic clutch 16 is disengaged. .
When the accelerator pedal 30 is depressed in this state, the mechanical guard 21 is rotated in the opening direction (upward in FIG. 2) against the biasing force of the return spring 24 in accordance with the amount of depression operation, and via the connecting spring 23. The throttle valve 12 also rotates in the same direction. Also, the accelerator pedal 30
When the depression operation of is released, the return spring 24
Since the mechanical guard 21 is rotated in the closing direction (downward in FIG. 2) by the urging force of the throttle valve 12, the throttle valve 12 is rotated in the same direction by the connecting spring 23. By depressing and releasing the accelerator pedal 30,
The rotation range of the throttle valve 12 is "fully open" in FIG.
And the throttle valve 1 allowed in ISC control
It is between the A position which is the upper limit of the rotation range of 2.

(Control Other Than Normal Cruise Control) In control other than cruise control, a connection signal is input from the CPU 26 to the electromagnetic clutch 16. The electromagnetic clutch 16 connects the motor 18 and the throttle valve 12 based on the input connection signal. Further, since the first switching signal is not input to the switch SW from the cruise determination control circuit 27 and the cruise cancel switch 29, the motor 18 is in a state in which the switch SW is off, and as a result, is driven at a low voltage. Therefore, the motor 18 operates with a low torque output, and the CPU 2
TRC control, ISC control based on the control signal from 6,
The throttle valve 12 is controlled to open / close in order to perform variable non-linear control or the like.

At this time, if the CPU 26 determines that the motor 18 is running out of control for some reason based on the signals input from the mechanical guard opening sensor S2 and the throttle valve opening sensor S1, the CPU 26 determines that the electromagnetic clutch 16 is in operation. The connection of the electromagnetic clutch 16 is released by inputting the connection release signal to the clutch power supply circuit 17.

Therefore, after the electromagnetic clutch 16 is disengaged, the driver depresses the accelerator pedal 30 to perform the retreat traveling. If the electromagnetic clutch 16 sticks and the connection cannot be released,
Return spring 2 attached to the mechanical guard 21
Since the urging force of No. 4 is larger than the low torque driving force of the motor 18, the throttle valve 12 can be returned to the fully closed position by releasing the operation depression of the accelerator pedal 30 and returning the accelerator pedal 30. Is established.

(Cruise Control) When performing cruise control (constant speed running), the CPU
26 is a drive circuit 1 for the motor 18 so that the vehicle speed becomes a preset speed (set vehicle speed) based on the auto-drive traveling permission signal from the cruise control determination circuit 27.
9, a control signal, a clutch power supply circuit 17 of the electromagnetic clutch 16 and a connection signal, and a switch SW receives a first switching signal. Based on this switching signal, switch SW
Is turned on.

As a result, the voltage higher than the rated voltage of the motor 18 from the battery B is applied to the power control circuit, and the control signal causes the motor 18 to operate with a high torque output (driving force). In addition, the electromagnetic clutch 1
Since 6 is connected, the motor 18 opens and closes the throttle valve 12 via the electromagnetic clutch 16 while resisting the biasing force T1 of the return spring 24 by the output of the high torque.

(Discontinuation of Cruise Control) When the cruise control is stopped, any one of the neutral input signal, the parking input signal and the brake input signal is input, or the cruise control switch 28 is used.
Is turned off (whether an off signal is input). That is, the cruise control determination circuit 27 sends the C signal to the auto drive traveling stop signal based on these input signals.
The signal is input to the PU 26, and the CPU 26 inputs the disconnection signal to the clutch power supply circuit 17 of the electromagnetic clutch 16 based on the auto drive traveling stop signal. Further, the cruise control determination circuit 27 further inputs the second switching signal to the switch SW. Further, the cruise cancel switch 29 also inputs the second switching signal to the switch SW.

Since the clutch power supply circuit 17 disconnects the electromagnetic clutch 16 in response to the disconnection signal, the opening / closing control of the throttle valve 12 can be performed thereafter by depressing the accelerator pedal 30.

The switch SW is turned off based on the second switching signal. As a result, a voltage lower than the rated voltage of the motor 18 is applied to the power control circuit. Even if the electromagnetic clutch 16 is stuck and the connection cannot be released, and the control signal is output to the motor 18 due to the runaway of the CPU 26, the biasing force of the return spring 24 attached to the mechanical guard 21 causes a low torque of the motor 18. Since the driving force is larger than the driving force, the throttle valve 12 can be returned to the fully closed position by releasing the operation depression of the accelerator pedal 30 and returning the accelerator pedal, and the fail safe is established. (A) In the above embodiment, the torque can be switched by driving the motor 19, which is a stepping motor, with high voltage or low voltage. Therefore, by this torque switching, both fail safe and cruise control can be established. (B) In the above-described embodiment, the motor 18 is driven at a low voltage and a low torque output is obtained in the control other than the cruise control at the normal time, so that the motor 18 runs out of control and the electromagnetic clutch 16 is engaged. Even if cannot be released, the biasing force of the return spring 24 is larger than the output (driving force) of the motor 18. As a result, if the depression operation of the accelerator pedal 30 is released, the throttle valve 12 can be returned to the fully closed position, and the fail safe can be established. (C) In the above embodiment, the second switching signal is input to the switch SW also from the cruise cancel switch 29 to turn off the switch SW. As a result,
Even if the second switching signal is not input from the cruise control determination circuit 27, the switch SW can be surely turned off. Therefore, the motor 18 can be reliably driven at a low voltage,
A low torque output is obtained. Therefore, the electromagnetic clutch 16
Even when the CPU 26 is stuck and the CPU 26 runs out of control, the driving force of the motor 18 is smaller than the urging force of the return spring 24, so that the throttle valve 12 can be returned to the fully closed position.

The present invention is not limited to the above-described embodiment, but may be implemented by appropriately modifying a part of the configuration without departing from the spirit of the present invention. (A) In the above-described embodiment, the motor 18 is driven at a low voltage and a high voltage by using the battery B as one power source. However, a battery having a high voltage power source and a low voltage power source is prepared, and a switching circuit for switching between these two power sources. May be provided, and low voltage driving and high voltage driving may be performed by switching this circuit.

(B) Further, in the above embodiment, the motor 18 is used.
The torque was switched by performing low-voltage driving and high-voltage driving, but the invention is not limited to this.
The point is that the type of motor and the drive circuit do not matter as long as the motor is controlled so that the torque can be switched.

(C) In the above embodiment, the cruise cancel switch 29 is composed of three switches, but the following cases are also possible. (A) The cruise cancel switch 29 is configured by a neutral switch, a parking brake switch, and a stop lamp switch, which perform neutral input, parking input, and brake input, respectively.

(B) The cruise cancel switch 29 is composed of a neutral switch and a parking brake switch, a neutral switch and a stop lamp switch, or a parking brake switch and a stop lamp switch.

From the matters described in this specification, the technical idea grasped other than the claims described in the scope of claims will be described together with their effects. (1) In Claim 1, the driving means is a motor, and the driving force changing means is a driving circuit that changes the output torque of the motor. With this configuration, the output torque of the motor can be easily changed.

[0046]

As described above in detail, according to the present invention, by changing the output of the driving means, it is possible to achieve both the constant speed running control and the fail safe.

According to the invention of claim 2, in addition to the effect of claim 1, the stop signal of the constant-speed traveling stopping means can be reliably performed even when the driving means continues to be driven due to factors such as runaway of the control means. Based on the above, the driving force of the driving means can be made smaller than the urging force of the urging means, and fail-safe can be established.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing a throttle valve control device of an embodiment.

FIG. 2 is a schematic diagram of the same.

FIG. 3 is a schematic diagram of a conventional throttle valve control device.

[Explanation of symbols]

10 ... Throttle body, 10a ... Intake passage, 12 ... Throttle valve, 16 ... Electromagnetic clutch, 18 ... Motor (driving means), 19 ... Driving circuit (switch SW, resistance R constitutes driving force changing means), 21 ... Mecha Guard, 24
... Return spring (constituting biasing means), 25 ...
Throttle ECU (constituting control means), 26 ... CP
U, 27 ... Cruise control determination circuit, 28 ... Cruise control switch, 29 ... Cruise cancel switch (constitutes constant speed traveling stopping means together with 28), 30 ...
Accelerator pedal, SW ... switch.

Claims (2)

[Claims] 1. A mechanical guard that is connected to an accelerator pedal and drives a throttle valve in the opening direction when the accelerator pedal is operated in the opening direction; and a mechanical guard that constantly biases the mechanical guard in the closing direction so that the accelerator pedal moves in the closing direction. When returned, the biasing means drives the throttle valve in the closing direction via the mechanical guard, the driving means for opening and closing the throttle valve, and the opening and closing control of the throttle valve according to the operating state via the driving means. In a throttle valve control device for an internal combustion engine including a control means, the driving force of the driving means is made larger than the urging force of the urging means during constant speed traveling control, and the urging means is energized when the constant speed traveling control is off. A throttle valve control device for an internal combustion engine, comprising a driving force changing means for making the force smaller than the force. 2. The constant speed traveling stopping means for outputting a stop command signal according to claim 1, wherein the control means has a constant speed traveling control function to control the driving means, and the constant speed control stopping means. Stopping the constant speed traveling control by the stop command signal, the driving force changing means applies the driving force of the driving means to the biasing means based on the stop command signal of the constant speed traveling stopping means. A throttle valve control device for an internal combustion engine, which is smaller than the power.