JPH11182308A - Throttle valve control device for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a valve control device for an internal combustion engine which drives the valve to obtain a target throttle opening, mechanically resets the valve to the specified opening, and has such improvement that error of the control characteristics is suppressed minimum at the specified opening, while operation delay and deviation of valve opening are suppressed. SOLUTION: In this device, a target throttle opening is input (S11), and the corresponding current command value to an electric motor is computed (S12). A default opening is referred to(S13). The target opening is compared to the default opening (S14). It is determined whether the target opening passes through the default point or not (S15). When the target opening does not pass through the default point, the current command value is determined to be one to the electric motor (S16). When the target opening passes through the default point, deviation between the target opening and the actual opening is computed (S17). A current correction factor according to the deviation is calculated (S18). The current command value to the electric motor is multiplied by the read current correction factor (S19). It is determined to be the corrected current command value to the electric motor.

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, and more particularly to a throttle valve control device for controlling a throttle valve driving device for driving a throttle valve based on a target throttle opening. The present invention relates to a throttle valve control device for an internal combustion engine provided with mechanical means for returning or holding a throttle valve to a predetermined throttle opening position when, for example, the driving force of the engine has disappeared.

[0002]

2. Description of the Related Art Heretofore, the elastic force of a spring for urging a throttle valve provided in an intake passage of an internal combustion engine in a valve opening direction via an operating shaft thereof and the elasticity of a spring for urging the throttle valve in a valve closing direction have been known. There is known a method of mechanically returning or holding a predetermined throttle opening (default opening) position by utilizing a balance with a force or the like.

Such a mechanism for returning or holding the throttle valve to the default opening position is, for example, that an electric actuator such as an electric motor is driven by a drive signal calculated in a control circuit based on a driver's accelerator operation amount or the like. A so-called electronically-controlled throttle valve that is driven and the throttle valve is rotated by a driving force via a gear transmission mechanism or the like so that the rotation of the throttle valve can be adjusted independently of the driver's accelerator operation. In the mechanism, for example, if there is any abnormality in the control system, the electric motor, etc., the throttle valve remains fully closed, and the engine cannot take air, and the engine starts and runs [for example, in the case of an emergency to a maintenance shop or the like. Traveling (limp home traveling)].

For example, Japanese Patent Application Laid-Open No. Hei 8-270488 discloses that, in a normal state, an operation amount of an accelerator pedal is detected and an electric actuator such as an electric motor is driven in accordance with the operation amount to open the throttle valve. On the other hand, when an abnormality occurs, the drive of the electric actuator is stopped,
A mechanical type that adjusts the opening of the throttle valve according to the operation amount of the accelerator pedal in this state by bringing an interlocking member that is linked to the throttle valve into contact with a throttle valve opening regulating member that is mechanically connected to the accelerator pedal. A technique for smoothly shifting to a throttle opening adjustment mode (limp home) is disclosed. In such a technique, when the abnormality occurs, the drive of the electric actuator is stopped to extinguish the driving force of the throttle valve. Then, by returning the throttle valve to the predetermined throttle opening position, the start of the engine and the limp home traveling are facilitated.

A mechanism for returning or holding the throttle valve to the default opening position is a conventional so-called auxiliary air since the throttle opening can be appropriately adjusted according to the air-conditioner load and the electric load in an electronically controlled throttle valve mechanism. Valves (ISC valve, FICD), etc. can be omitted. On the other hand, if the auxiliary air valve is omitted, the throttle valve can be bypassed at startup and cannot be taken in from the auxiliary air bypass. If the vehicle is fully closed, there is a risk that intake may not be performed at the time of starting, and this is provided in order to avoid a possibility that starting cannot be performed unless the driver depresses the accelerator pedal.

[0006]

However, as described above, the elastic force of the spring that urges the throttle valve in the valve opening direction and the elastic force of the spring that urges the throttle valve in the valve closing direction via the operating shaft are as described above. In the structure in which the throttle valve is mechanically returned to or held at a predetermined throttle opening (default opening) position using the balance or the like, that is, the structure in which the throttle valve is mechanically returned or held to the default opening, When the throttle valve is controlled based on a mathematical model (reference model) as in an electronically controlled throttle valve mechanism, for example, before and after a default opening degree, an inertia fluctuation of a component and an electric actuator such as an electric motor are performed. The amount of backlash in the gear transmission mechanism that transmits the drive of the throttle to the throttle valve differs from the mathematical model of the throttle valve control system. That there is a throttle opening degree characteristic to become error region, this error area, delay in operation of the throttle valve, produces a deviation.

FIG. 8 (A) shows the throttle valve control characteristic when the throttle valve opening difference is large, and FIG. 8 (B) shows the throttle valve control characteristic when the throttle valve opening difference is small. There is a portion where the actual opening of the throttle valve is significantly different from the target opening. Accordingly, the present invention has been made in view of the above-described conventional problems, and when the throttle valve is driven based on the target throttle opening and the driving force of the throttle valve is extinguished, for example, the throttle valve is driven by mechanical means. A throttle valve control device for an internal combustion engine configured to return or hold the throttle valve to a predetermined throttle opening position. It is an object of the present invention to provide a throttle valve control device for an internal combustion engine that can suppress a deviation of a throttle valve opening and the like.

[0008]

According to the present invention, as shown in FIG. 1, a throttle control means for controlling a throttle valve driving means for driving a throttle valve based on a target throttle opening is provided. A throttle valve control device for an internal combustion engine provided with mechanical means for returning or holding the throttle valve to a predetermined throttle opening position, wherein whether the target throttle opening has passed a point where the predetermined throttle opening is reached or not. Determining means for determining whether
Deviation calculating means for calculating a deviation between the target throttle opening and the actual throttle opening when it is determined by the determining means that the target throttle opening has passed a point at which the target throttle opening becomes a predetermined throttle opening; Correction means for correcting the control command value to the throttle valve driving means.

According to a second aspect of the present invention, there is provided an accelerator opening detecting means for detecting an accelerator opening, a throttle opening calculating means for calculating a throttle opening corresponding to the accelerator opening, and at least the throttle opening. And a target throttle opening calculating means for calculating a final target throttle opening based on the target throttle opening.

According to a third aspect of the present invention, the mechanical means for returning or holding the throttle valve to a predetermined throttle opening position includes an elastic member for urging the throttle valve in a valve opening direction via an operating member thereof. The present invention is characterized in that the throttle valve is returned to or held at a predetermined throttle opening position by balancing the elastic force and the elastic force of the elastic member biasing in the valve closing direction.

The invention according to claim 4 is characterized in that the throttle valve is opened and closed via a gear transmission mechanism by the driving force of the throttle valve driving means. According to a fifth aspect of the present invention, the mechanical means for returning or holding the throttle valve to the predetermined throttle opening position stops the driving of the throttle valve driving means when the abnormality of the throttle valve control system occurs, thereby driving the throttle valve. The characteristic is characterized in that the throttle valve is returned to a predetermined throttle opening position when is extinguished.

According to a sixth aspect of the present invention, the correction means includes:
A table is provided in which the relationship between the deviation and the correction coefficient of the control command value is determined in advance, and the control command value to the throttle valve driving means is multiplied by a correction coefficient corresponding to the read deviation with reference to the table to obtain the throttle. It is characterized in that the control command value to the valve drive means is corrected.

According to a seventh aspect of the present invention, the opening of the throttle valve interposed in the intake passage is controlled based on a mathematical model, and the throttle valve is returned to or held at a predetermined throttle opening position by mechanical means. The throttle valve control device for an internal combustion engine described above is characterized in that a means for correcting a throttle valve control characteristic different from the mathematical model before and after the predetermined throttle opening is provided.

The operation of the present invention will be described. In the invention according to claim 1, the throttle valve is controlled based on the target throttle opening. Further, for example, when the driving force of the throttle valve is extinguished, for example, the throttle valve is returned to a predetermined throttle opening position or held.

When it is determined that the target throttle opening has passed the point where the throttle opening reaches the predetermined throttle opening, a deviation between the target throttle opening and the actual throttle opening is calculated, and the throttle valve driving is performed in accordance with the deviation. The control command value to the means is corrected. In this way, by correcting the throttle opening when the target throttle opening passes the point where the target throttle opening reaches the predetermined throttle opening, for example, before and after the predetermined throttle opening, for example, inertia fluctuation of components and throttle valve driving The occurrence of an error region having throttle control characteristics different from the mathematical model of the throttle valve control system can be minimized by the amount of gear backlash in the gear transmission mechanism that transmits the drive of the means to the throttle valve.

In the invention according to claim 2, the target throttle opening is calculated based on at least the throttle opening corresponding to the accelerator opening. In the invention according to claim 3, the throttle valve includes an elastic force of an elastic member that urges in a valve opening direction via an operating member when the driving force of the throttle valve is extinguished, for example, and a valve closing direction. Is returned to or held at a predetermined throttle opening position by the balance with the elastic force of the elastic member that urges the elastic member.

In the invention according to claim 4, the driving force of the throttle valve driving means is transmitted to the throttle valve via a gear transmission mechanism. In the invention according to claim 5, when an abnormality occurs in the throttle valve control system, the drive of the throttle valve driving means is stopped, so that the throttle valve is returned to a predetermined throttle opening position, and the throttle valve is maintained in a fully closed state. The engine is not left standing, and the engine is started and the limp home is easily driven.

In the invention according to claim 6, a correction coefficient corresponding to the deviation read out with reference to a table in which a relationship between the deviation and the correction coefficient of the control instruction value is determined in advance is used as the control instruction value to the throttle valve driving means. Multiplied. In the invention according to claim 7, by correcting a throttle valve control characteristic different from the mathematical model of the throttle valve control system before and after the predetermined throttle opening, the occurrence of an error region having a throttle valve control characteristic different from the mathematical model is minimized. Can be limited.

[0019]

According to the first and seventh aspects of the present invention, it is possible to minimize the delay in the operation of the throttle valve and the occurrence of deviation, and to improve the controllability of the throttle valve to the target opening. it can. According to the second aspect of the present invention, the target throttle opening can be easily calculated based on at least the throttle opening corresponding to the accelerator opening.

According to the third aspect of the present invention, the mechanical means for returning or holding the throttle valve to the predetermined throttle opening position can be easily constituted by two elastic members such as two springs. According to the fourth aspect of the present invention, an error region having a throttle control characteristic different from that of the mathematical model of the throttle valve control system occurs due to the gear backlash in the gear transmission mechanism. , Deviation can be prevented as much as possible, and the controllability of the throttle valve to the target opening can be improved.

According to the fifth aspect of the present invention, the engine can be easily started and limp home running can be easily performed by returning the throttle valve to the predetermined throttle opening position when an abnormality occurs in the throttle valve control system. In addition, it is possible to minimize delays and deviations in the operation of the throttle valve, thereby improving the controllability of the throttle valve to the target opening.

According to the sixth aspect of the invention, the correction means multiplies the control command value to the throttle valve driving means by the correction coefficient read with reference to the table.
It can be easily configured.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the attached drawings. 2 and 3 are views showing an embodiment of the throttle valve control device of the present invention, and are views showing the configuration of a drive system of the throttle valve. In this figure, a throttle body 1 provided in an intake passage of an internal combustion engine is provided with a butterfly type throttle valve 2. This throttle valve 2 has a disc-shaped valve body 4 on a throttle shaft 3.
The throttle shaft 3 penetrates the throttle body 1 and is rotatably supported by bearings 5.

An electric motor 7 as a throttle actuator (throttle valve driving means) is connected to the throttle shaft 3 of the throttle valve 2 via a gear transmission mechanism 6, and the opening of the throttle valve 2 is controlled by driving the electric motor 7. It can be adjusted. On the other hand, an interlocking member 8 is connected to the throttle shaft 3, and the interlocking member 8 is linked to a default limp home link 10 via a default spring 9.

The default limp home link 10 is connected to a fixed portion via a throttle return spring 11. Here, the default spring 9 elastically urges the throttle shaft 3 in the throttle valve opening direction, and the throttle return spring 1
Numeral 1 urges the throttle shaft 3 elastically in the throttle valve closing direction.

On the other hand, an accelerator interlocking member 13 is fixed to an accelerator wire 12 fixed to an accelerator pedal as an accelerator operation member. This accelerator interlocking member 1
3 is elastically urged by a spring 14 in a direction to close the throttle valve 2. The end of the accelerator interlocking member 13 opposite to the portion fixed to the accelerator wire 12 is interposed with a link 15 provided on the default limp home link 10 via a predetermined interval (limp home interference allowance). They are spaced apart.

In FIG. 2, reference numeral 16 denotes a wire for an automatic speed control device, 17 denotes an accelerator upper limit stopper, 18 denotes an accelerator lower limit stopper, 19 denotes a throttle upper limit stopper, and 20 denotes a minimum clearance between the throttle valve 2 and the throttle body 1. Is a default adjusting screw for adjusting the throttle adjustment screw. FIG.
FIG. 3 is a control block diagram of the throttle valve.

In this figure, an engine control unit 22 includes a main CPU 23 as an abnormality detecting means and an electric motor stopping means, a throttle controlling means and a throttle controlling CPU 24 as a judging means, a deviation calculating means and a correcting means according to the present invention. And a throttle drive circuit 25. The main CPU 23 and the throttle control CPU 24 receive an accelerator operation amount (accelerator opening) signal from an accelerator sensor 26, a throttle opening signal from a throttle opening sensor 27, an engine coolant temperature signal from a water temperature sensor 28, and the like, respectively. Is entered.

A throttle drive circuit 25 is connected to the throttle control CPU 24, and the electric motor 7 is connected to the throttle drive circuit 25. Then, the throttle control CPU 24 calculates the throttle opening based on the operation amount of the accelerator pedal, and controls the electric motor 7 based on the calculation result to drive the throttle valve 2. That is, the opening degree of the throttle valve 2 is set in accordance with the operation amount of the accelerator pedal.

FIG. 5 is a flowchart showing the details of throttle control by the throttle control CPU 24 during normal running. In step 1, a signal from an accelerator sensor is fetched, and the accelerator pedal operation amount (accelerator opening) at that time is taken. Degree). In step 2, the throttle opening θ _ACC corresponding to the accelerator pedal operation amount (accelerator opening) is calculated.

In step 3, a throttle opening θ _ISC for idling speed (ISC) control according to the engine coolant temperature is calculated. In step 4, a throttle opening corresponding to the operation amount of the accelerator pedal (accelerator opening) is calculated. Opening θ _ACC
And added to the throttle opening theta _ISC for ISC control calculates the final target throttle opening theta _FIN. Then, in step 5, the final target throttle opening θ _{FIN is set} to D
/ A conversion and output to the throttle drive circuit 25. As a result, the energization of the electric motor 7 is controlled as described above, and the opening of the throttle valve 2 is adjusted to a predetermined opening.

The drive system of the throttle valve during normal running is in an operating state as shown in FIG. On the other hand, when the main CPU 23 detects an abnormality,
The drive of the electric motor 7 is stopped by a command from U23. Then, the throttle shaft 3 is rotated to the closing side of the throttle valve 2 by the throttle return spring 11, but the default spring 10 restricts the sliding to the closing side by a predetermined amount or more, and the throttle valve 2 is closed.
Is restricted to a rotation position at which a predetermined throttle opening (hereinafter, default opening) is reached.

That is, the throttle valve 2 is mechanically opened at a predetermined throttle opening by balancing the elastic force of the default spring 10 urged in the valve opening direction and the elastic force of the throttle return spring 11 urged in the valve closing direction. Degrees, that is, returned to the default opening position. When the accelerator pedal is operated in this state, the accelerator interlocking member 13 is operated via the accelerator wire 12, and the end of the accelerator interlocking member 13 opposite to the fixed portion with the accelerator wire 12 is used for the default limp home. Link 1
0, the link 10 for default limp home is operated by the operation of the accelerator interlocking member 13 according to the accelerator operation amount, and the throttle shaft 3 rotates following the link. The opening of the throttle valve 2 is set in accordance with the operation amount of the pedal (FIG. 3
(B)).

In this manner, limp home traveling (mechanical throttle opening adjustment mode) becomes possible. Next, the control contents of the present invention will be described based on the flowchart of FIG. In step 11, a target throttle opening is input, and in step 12, a control command value (current command value) for the electric motor 7 corresponding to the target throttle opening is calculated.

In step 13, the default opening is referred to, and in step 14, the target throttle opening is compared with the default opening. In step 15, the point at which the target throttle opening becomes the default opening (default point) )
Is determined, and if the vehicle does not pass the default point, the routine proceeds to step 16, where the current command value calculated in step 12 is determined as it is as the current command value to the electric motor 7.

On the other hand, if it is determined in step 15 that the vehicle has passed the default point, in step 17 a deviation between the target throttle opening and the actual throttle opening is calculated, and the routine proceeds to step 18, where this deviation is calculated. The current correction coefficient is calculated according to. In this case, for example, as shown in FIG. 7, a table in which the relationship between the deviation ΔTVO (deg / s) and the current correction coefficient (%) is provided in advance, and the table is referred to according to the deviation with reference to this table Read the current correction coefficient.

In step 19, the current command value for the electric motor 7 calculated in step 12 is multiplied by the current correction coefficient read in step 18 (current command value for electric motor × current correction coefficient). At 16, the current command value to the electric motor 7 corrected at step 19 is determined. As described above, when the target throttle opening has passed the default point, the current command value to the electric motor 7 is corrected based on the deviation between the target throttle opening and the actual throttle opening, and the throttle opening is adjusted. By performing the correction,
Before and after the default opening, for example, the amount of backlash of the gear in the gear transmission mechanism 6 that transmits the fluctuation of the inertia of the components and the drive of an electric actuator such as the electric motor 7 to the throttle valve 2 is equal to the backlash of the throttle valve control system. It is possible to minimize the occurrence of an error region having a throttle control characteristic different from that of the mathematical model.
Operation delay and deviation can be prevented as much as possible.
Controllability of the throttle valve to the target opening can be improved.

[Brief description of the drawings]

FIG. 1 is a diagram corresponding to claims of the present invention.

FIG. 2 is a diagram showing an embodiment of a throttle valve control device of the present invention, showing a configuration of a drive system of the throttle valve.

3A and 3B are diagrams showing an operation state of a drive system of the throttle valve, in which FIG. 3A shows an operation state during normal driving, and FIG.

FIG. 4 is a control block diagram of a throttle valve.

FIG. 5 is a flowchart showing the details of throttle control during normal running.

FIG. 6 is a flowchart illustrating control contents of the present invention.

FIG. 7 is a diagram showing a table defining a relationship between a deviation ΔTVO (deg / s) and a current correction coefficient (%).

8A and 8B are diagrams for explaining a conventional problem, in which FIG. 8A shows a throttle valve control characteristic when the throttle valve opening is large, and FIG. 8B shows a throttle valve control characteristic when the throttle valve opening is small.

[Explanation of symbols]

 2 Throttle valve 6 Gear transmission mechanism 7 Electric motor 8 Default spring 9 Default limp home link 11 Throttle return spring 22 Engine control unit 23 Main CPU 24 Throttle control CPU 25 Throttle drive circuit 26 Accelerator sensor 27 Throttle opening sensor

Claims (7)

[Claims] 1. A throttle control means for controlling a throttle valve driving means for driving a throttle valve based on a target throttle opening degree, and a mechanical means for returning or holding the throttle valve to a predetermined throttle opening position. In a throttle valve control device for an internal combustion engine, determining means for determining whether or not the target throttle opening has passed a point at which the predetermined throttle opening is reached; and determining that the target throttle opening is a predetermined throttle opening by the determining means. A deviation calculating means for calculating a deviation between the target throttle opening and the actual throttle opening when it is determined that a certain point has been passed; and a control command value to the throttle valve driving means in accordance with the deviation. A throttle valve control device for an internal combustion engine, comprising: correction means. 2. An accelerator opening detecting means for detecting an accelerator opening, a throttle opening calculating means for calculating a throttle opening corresponding to the accelerator opening, and a final target based on at least the throttle opening. 2. The throttle valve control device for an internal combustion engine according to claim 1, further comprising: a target throttle opening calculating means for calculating a throttle opening. 3. The mechanical means for returning or holding the throttle valve to a predetermined throttle opening position includes an elastic force of an elastic member for urging the throttle valve in a valve opening direction via an operating member thereof, and a valve closing direction. And returning the throttle opening to a predetermined throttle opening position or holding the throttle opening position by balancing the elastic force of the elastic member biasing the throttle member.
A throttle valve control device for an internal combustion engine according to claim 1. 4. The throttle of an internal combustion engine according to claim 1, wherein said throttle valve is opened and closed by a driving force of said throttle valve driving means via a gear transmission mechanism. Valve control device. 5. A mechanical means for returning or holding the throttle valve to a predetermined throttle opening position, wherein when an abnormality occurs in the throttle valve control system, the driving of the throttle valve driving means is stopped to eliminate the driving force of the throttle valve. The throttle valve control device for an internal combustion engine according to any one of claims 1 to 4, wherein the throttle valve is configured to return the throttle valve to a predetermined throttle opening position when the throttle valve is opened. 6. The correction means is provided with a table in which the relationship between the deviation and the correction coefficient of the control command value is determined in advance, and by referring to the table, a correction coefficient corresponding to the read deviation is sent to the throttle valve driving means. 6. The throttle valve control device for an internal combustion engine according to claim 1, wherein the control command value to the throttle valve driving means is corrected by multiplying the control command value by the control command value. . 7. An internal combustion engine in which the opening of a throttle valve interposed in an intake passage is controlled based on a mathematical model, and the throttle valve is returned to or held at a predetermined throttle opening position by mechanical means. A throttle valve control device for an internal combustion engine, comprising: means for correcting a throttle valve control characteristic different from a mathematical model before and after the predetermined throttle opening degree.