JP2591544B2 - Throttle actuator and engine control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a throttle actuator for driving a throttle valve and an engine control device for controlling an amount of air supplied to an engine.

[0002]

2. Description of the Related Art Generally, a throttle valve is provided in an intake passage for supplying intake air to an engine, and the amount of intake air is controlled by adjusting the opening of the throttle valve. Conventionally, an accelerator pedal and a throttle valve are mechanically connected by a wire or the like, and when the accelerator pedal is depressed, the throttle valve is gradually opened in accordance with the depression. That is, the throttle opening is uniquely determined according to the amount of depression of the accelerator pedal.

On the other hand, it has been desired to set the throttle valve opening at the most preferable position corresponding to the running state of the vehicle without being restricted by the depression amount of the accelerator pedal. For example, in order to prevent the air-fuel mixture from becoming lean during acceleration, it has been desired to control the opening degree of the throttle valve to be small to limit the amount of intake air. Further, it has been desired to control the intake air amount by adjusting the opening degree of the throttle valve so as to match a preset speed.

[0004] To meet such demands, there is known a throttle actuator that adjusts the opening of a throttle valve using hydraulic pressure. This connects the throttle valve with the hydraulic piston,
The hydraulic piston is slidably held in a hydraulic cylinder, and controls the oil pressure of oil supplied to the hydraulic cylinder. Such a technique is disclosed, for example, in JP-A-63-1614.
No. 6 is described.

[0005]

However, in the above prior art, for example, a control unit that outputs a control signal to a throttle actuator falls into an abnormal state,
Alternatively, when noise is superimposed on the signal from the control unit, a high oil pressure is supplied to the hydraulic cylinder, and there is a risk that the throttle valve may be controlled so as to increase the opening degree regardless of the driver's intention. . That is, when the means for supplying oil pressure to the piston in the hydraulic cylinder becomes abnormal, even if the driver releases the accelerator and indicates the intention to decelerate the vehicle, the throttle valve is not closed and the vehicle runs away. There was a danger of doing it.

An object of the present invention is to provide a throttle actuator configured to close a throttle valve at least when a driver releases an accelerator.

Another object of the present invention is to provide an engine control device for controlling an intake air amount such that a predetermined idle air amount which is not excessive is supplied to an engine at least when a driver releases an accelerator. Is to do.

[0008]

In order to achieve the above object, according to the present invention, there is provided a main cylinder having a cylindrical inner peripheral surface, and an output slidably held on the inner peripheral surface of the main cylinder. A piston, an output rod for mechanically connecting the output piston and the throttle valve, and a pressure source for applying pressure to a fluid held in the main cylinder to move the output rod, wherein an accelerator pedal is a predetermined one. It is configured to have a port for releasing the pressure applied to the fluid when returned to the position.

[0009] Further, it has a main cylinder having a cylindrical inner peripheral surface, an output piston slidably held on the inner peripheral surface of the main cylinder, and a throttle valve provided in an intake passage. The output piston is configured to be mechanically connected to a throttle valve, and further, the throttle valve is controlled by controlling a pressure applied to an attachment held in the main cylinder according to an operating state of an engine. And a port for releasing the pressure applied to the fluid in order to return the throttle valve to the idle position when the accelerator pedal is returned to the predetermined position.

[0010]

With the above construction, when the accelerator pedal is released and the accelerator pedal is returned to a predetermined position,
The pressure on the oil in the main cylinder acts to escape through the port. For this purpose, the throttle valve mechanically connected to the output piston closes.

In this way, when the accelerator pedal is released, the throttle valve returns to the idle position, so that a predetermined idling air amount is supplied to the engine.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings. First, a system configuration diagram of the present embodiment is shown in FIG. The intake air taken in through the air cleaner 10 is controlled by a throttle valve 4 provided in a throttle chamber 6, and is guided to a cylinder of the engine 1 through an intake pipe 2. On the other hand, the fuel supplied from the injection valve 16 is mixed with the intake air, becomes a mixture, and is guided to the cylinder of the engine 1. The air-fuel mixture is discharged from the exhaust pipe 3 to the outside after undergoing a compression and explosion process.

The depression amount of the accelerator 9 is determined by an accelerator sensor 8, and the water temperature of the engine 1 is determined by a water temperature sensor 12.
The rotation angle of the crankshaft 18 is detected by the crank angle sensor 13, and the rotation angle of the throttle valve 4 is detected by the throttle valve opening sensor 17, and respective detection signals are input to the control unit 14.

The control unit 14 calculates the amount of intake air by calculating the signals from the sensors. Further, the control unit 14 controls the intake air by driving the throttle actuator 5 based on the calculation result. The intake air amount actually supplied to the engine is detected by the intake air amount sensor 7, and this signal is input to the control unit 14. The control unit 14 calculates the fuel supply amount based on the output signal of the intake air amount sensor 7 and drives the injection valve 16 to control the fuel supply.

FIG. 1 shows details of the throttle actuator 17. The main cylinder 31 is configured to withstand a predetermined internal pressure, and its inner peripheral surface has a cylindrical shape and is relatively smooth. Main cylinder 31
The input piston 32 and the output piston 36 are held in the inside so as to slidably contact the inner peripheral surface. An input piston 32 is held at one end of the main cylinder 31 and an output piston 32 is held at the other end, and a fluid (oil) is tightly extracted between the input piston 32 and the output piston 36. Has been entered. An O-ring 41 is fitted in a groove on the outer peripheral portion of the input piston 32, and maintains airtightness between the outer peripheral surface of the input piston 32 and the inner peripheral surface of the main cylinder 31. Similarly, an O-ring 42 is fitted in a groove on the outer peripheral portion of the output piston 36, and maintains airtightness between the outer peripheral surface of the output piston 36 and the inner peripheral surface of the main cylinder 31.

The input piston 32 has a main cylinder 3
An input rod 34 is provided through one end of the input rod. The input rod 34 is mechanically connected to the accelerator 9 described above, and is configured to move to the right (FIG. 1) in the figure when the accelerator 9 is depressed. Input rod 34
Is provided with a cylindrical spring receiver 40 at a position outside the end of the main cylinder 31. A spring 33 is inserted between the spring receiver 40 and the end of the main cylinder 31, and the spring 33 is
4 is pressed by a predetermined urging force.

On the other hand, the output piston 36 is provided with an output rod 38 penetrating the other end of the main cylinder 31. The throttle valve 4 is mechanically connected to the output rod 38, and the opening degree of the throttle valve 4 increases when the output rod 38 moves to the right side in the drawing (FIG. 1). The output rod 38 is provided with a spring receiver 43 at a position inside the end of the main cylinder 31.
A spring 37 is inserted between the spring receiver 43 and the end of the main cylinder 31.
Presses the output rod 38 with a predetermined urging force.

The portion of the main cylinder 31 near the input rod 34 is open, and this opening communicates with the oil sump 44 via a port A45. Also, input piston 3
The oil held between the piston 2 and the output piston 36 can be moved to the oil sump 44 via the port A. The oil sump 44 keeps the oil held between the input piston 32 and the output piston 36 constant. It works to keep quantity. Port A
The opening of the main cylinder 31 is provided at a position closed by the outer peripheral surface of the input piston 32 when the accelerator 8 is depressed and the input piston 32 moves by a predetermined amount from the initial position.

On the other hand, the sub-cylinder 51 is configured to withstand a predetermined internal pressure, and its inner peripheral surface has a cylindrical shape and is relatively smooth. A drive piston 53 is held inside the sub-cylinder 51 so as to slidably contact the inner peripheral surface. An O-ring 52 is fitted into a groove on the outer peripheral portion of the drive piston 53, and maintains airtightness between the outer peripheral surface of the drive piston 53 and the inner peripheral surface of the sub cylinder 51.

One of the drive pistons 53 is filled with oil. A screw 54 is formed on the other end of the drive piston 53, and the screw 54 fits with a screw 55 of a motor shaft 56. The motor shaft 56 is rotated by a motor 57. Control unit 1 described above
When the motor shaft 56 is rotated by the signal of No. 4, the screw 54
The drive piston 53 is moved by the action of the screw 55.

The main cylinder 31 has an opening near the center, and this opening communicates with the outside through an input port B46. On the other hand, an end portion of the sub cylinder 51 opposite to the motor 57 is open and communicates with the main cylinder 31 via the input port C58, the pressure pipe 35, and the input port B46. As described above, the oil held in the sub cylinder 51 and the oil held in the main cylinder 31 can move with each other via the input port C58, the pressure pipe 35, and the input port B.

Next, the operation of the thus configured throttle actuator 17 will be described. Accelerator 9
Is not depressed, the input piston 32 is at a position as shown in FIG. In this state, the oil held in the main cylinder 31 and the oil held in the oil reservoir 44 can move freely.

In this state, little pressure is applied to the oil held between the input piston 32 and the output piston 36, and the output piston 36 is urged by the spring 37, and is located most rightward in the drawing. Will be done. The opening of the throttle valve 4 (idle position) is set so that a predetermined amount of idle air is supplied to the engine in accordance with the position of the output piston 36.

When the accelerator 9 is depressed from this state, the input rod 34 moves to the right in FIG.
2 moves to the right in the figure. Further, when the accelerator 9 is depressed, the tip of the input piston 32 moves to the position shown in FIG.
The communication between 1 and the oil sump 44 is cut off. Further, when the accelerator 9 is depressed and the input piston 32 moves rightward in the figure, pressure is applied to the oil in the main cylinder 31 and the output piston 36 moves rightward in the figure, and the throttle valve connected to the output rod 38 4 acts to open from the idle position.

On the other hand, in this state (the tip of the input piston 46 is located on the right side of B in the figure), when the control unit 14 determines to increase the amount of intake air, the motor 57 is rotated to drive the drive piston 53. Move to the right in the figure.
When the drive piston 53 moves to the right in the drawing, pressure is applied to the oil held in the main cylinder 31 via the pressure pipe 35, and the output piston 36
Is moved to the right in the figure against the urging force of
The opening of the throttle valve 4 increases. Conversely, when the control unit 14 determines to reduce the intake air amount, the motor 57
To move the drive piston 53 to the left side in the figure. When the drive piston 53 moves to the left in the drawing, the output piston 36 moves to the left in the drawing, and the opening of the throttle valve 4 decreases.

Next, a case where the motor 57 becomes abnormal when the accelerator pedal 9 is depressed will be described. For example, if the output signal of the control unit 14 becomes abnormal and the motor 57 is controlled so as to supply the intake air larger than the actually required intake air amount to the engine, the vehicle is accelerated irrespective of the driver's will. It is a danger. Similarly, if the motor 57 stops operating due to burn-in while being controlled so as to increase the intake air amount, it is similarly dangerous.

When the accelerator pedal 9 is depressed and the input piston 32 moves to a position to close the port A45,
Pressure is applied to the oil held between the input piston 32 and the output piston 36, and the output piston 36 becomes movable. From this state, the input piston 3
When 2 is moved to the right in the figure, the output piston 36 is moved to the right in the figure, and the throttle valve 4 is opened from the idle position. On the other hand, at this time, when the motor 57 rotates and the driving piston 53 is moved to the right in the drawing by the action of the screw portion 54 and the screw portion 55, the output piston 36 is also moved to the right, and The opening of the valve 4 increases. At this time, the rotation of the motor 57 becomes abnormal and the drive piston 53
When an excessive pressure is applied to the oil held between the input piston 32 and the output piston 36, the output piston 36 is further moved to the right in the drawing. For this reason, the opening degree of the throttle valve 4 becomes larger than the driver's intention, and the vehicle intended by the driver cannot travel.

However, even if the rotation of the motor 57 becomes abnormal and the throttle valve 4 is opened more than necessary, the driver releases the accelerator pedal 9 with an intention to decelerate, and the input is made by the urging force of the spring 33. When the piston 32 is returned to the predetermined position, the input piston 32 makes the main cylinder 31 communicate with the port A45. As a result, the pressure of the oil held between the input piston 32 and the output piston 36 is released to the oil reservoir 44 via the port A45, and the output piston 36 is moved to the left side in the figure by the urging force of the spring 37. The throttle valve 4 is returned to the idle position.

As described above, in this embodiment, even if the rotation of the motor 57 becomes abnormal and the throttle valve 4 is opened more than the driver's intention, the throttle valve 4 will reach the idle position when the accelerator pedal is released. Returning prevents the supply of an excessive amount of intake air to the engine, thereby preventing runaway of the vehicle and the like.

Also, after the motor 57 rotates so as to open the throttle valve 4 with the driver depressing the accelerator pedal 9, even if the motor 57 is locked as it is, if the accelerator pedal 9 is released once. , The port A45 communicates, and the throttle valve 4 returns to the idle position. When the accelerator pedal 9 is depressed again, no matter what position the drive piston 53 is in, the accelerator pedal 9
The output piston 36 is moved according to the amount of depression of the throttle valve, and the opening of the throttle valve 4 is determined.

Next, a second embodiment is shown in FIG. The parts having the same numbers as those in the first embodiment have the same functions.

The second embodiment is the same as the first embodiment except that the input piston 32 and the output piston 62 have different sectional areas.

By increasing the cross-sectional area of the output piston 62 with respect to the cross-sectional area of the input piston 32, the force applied to the output piston 62 when the pressure generated by the drive piston 53 is applied to the main cylinder 31 is increased.
That is, the reaction force to the input piston 32 when the drive piston 53 operates is reduced.

[0034]

As described above, in the throttle actuator of the present invention, the throttle valve can be closed to the idle position when the accelerator pedal is released. Further, with the engine control device of the present invention, it is possible to perform control such that when the accelerator pedal is released, a predetermined non-excessive amount of idling air is supplied to the engine.

[Brief description of the drawings]

FIG. 1 is a system configuration diagram.

FIG. 2 is a detailed view of a throttle actuator.

FIG. 3 is a diagram showing a second embodiment.

[Explanation of symbols]

4 throttle valve, 8 accelerator pedal, 31 main cylinder, 36 output piston, 38 output rod, 51 sub cylinder, 53 driving piston, 57 motor, 45
... Port A.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Eiji Sato, Inventor 502, Kandate-cho, Tsuchiura-shi, Ibaraki Pref. Machinery Research Laboratory, Hitachi, Ltd. (56) References JP-A-60-247017 (JP, A) JP-A-4-224239 (JP, A) JP-A-63-16146 (JP, A)

Claims (10)

(57) [Claims] An input piston mechanically connected to an accelerator pedal, a first cylinder slidably holding the input piston, an output piston mechanically connected to a throttle valve, and an output piston A second cylinder that slidably holds the first cylinder, a driving piston that operates in response to a signal from the control unit, and a third cylinder that slidably holds the driving piston. The second cylinder and the third cylinder are configured to communicate with each other, fill the communication portion with a fluid, and transmit a pressure applied to the fluid by the input piston or the drive piston to the output piston. A port for releasing pressure applied to the fluid when the accelerator pedal is returned and the input piston moves to a predetermined position. Torque actuator. Wherein Oite to claim 1, a throttle actuator, characterized in that it comprises a sump communicating with said port. 3. The throttle actuator according to claim 1 , further comprising a spring for urging the input piston in a direction opposite to a direction in which the input piston moves when the accelerator is depressed. 4. The throttle actuator according to claim 3 , further comprising a spring for urging the output rod in a direction in which the throttle valve closes. 5. The throttle actuator according to claim 4 , further comprising a motor, wherein the drive piston is configured to be moved by the motor. 6. The throttle actuator according to claim 1 , wherein an outer diameter of the input piston is different from an outer diameter of the output piston. 7. The throttle actuator according to claim 6 , wherein an outer diameter of the output piston is larger than an outer diameter of the input piston. 8. An input piston which is moved by depressing an accelerator pedal, a first cylinder which slidably holds the input piston, a throttle valve provided in an intake passage for controlling an amount of intake air, and a throttle. An output piston that opens and closes a valve, a second cylinder that slidably holds the output piston, a control unit that detects an operating state of the engine and generates a signal, and a drive that moves by a signal from the control unit A piston, and a third cylinder slidably holding the driving piston.
The third cylinder and the third cylinder are communicated with each other, the communication portion is filled with fluid, and the pressure applied to the fluid by the input piston or the drive piston is transmitted to the output piston, and An engine control device having a port for releasing pressure applied to the fluid so that the throttle valve returns to an idle position when an accelerator pedal is returned and the input piston moves to a predetermined position. 9. The method of claim 8, and supplies the fuel supply amount calculating means for calculating a fuel supply amount based on the intake air amount sucked into the engine, the fuel in response to the signal of the fuel supply amount calculation means An engine control device comprising a fuel supply device. 10. An input piston mechanically connected to an accelerator pedal, a first cylinder slidably holding the input piston, an output piston mechanically connected to a throttle valve, and an output piston. A second cylinder that slidably holds the first cylinder, a driving piston that operates in response to a signal from the control unit, and a third cylinder that slidably holds the driving piston. The second cylinder and the third cylinder are configured to communicate with each other, fill the communication portion with a fluid, and transmit a pressure applied to the fluid by the input piston or the drive piston to the output piston. When the accelerator pedal is returned and the input piston moves to a predetermined position, the output piston is corrected regardless of the position of the drive piston. Throttle actuator, characterized in that it includes a mechanism for returning to.