JP2004036565A - Throttle valve device and its controlling method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a throttle valve device capable of reducing power consumption of an electric motor, and its controlling method. <P>SOLUTION: The throttle valve device 1 for adjusting the suction air quantity of an engine combustion chamber is equipped with a throttle valve 6 provided to block a suction passage 5, an electric motor 7 for driving the throttle valve 6, and a control unit 3 for controlling the energizing current capacity. The control unit 3 gradually reduces the energizing current capacity of the electric motor 7 so that the opening of the throttle valve 6 does not move to the closing side, and controls the reduced electric current capacity to the minimum energizing current capacity. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a throttle valve device, and more particularly, to a method for controlling the amount of current supplied to an electric motor.
[0002]
[Prior art]
Generally, in order to appropriately control the combustion state in the combustion chamber of the engine, it is necessary to control and adjust the amount of air taken into the combustion chamber of the engine. As a device for controlling and adjusting the amount of air taken into the combustion chamber of the engine, for example, a throttle valve device mounted on an automobile engine is well known.
[0003]
The throttle valve device has a throttle valve installed so as to close an intake passage of an engine combustion chamber, and an electric motor for driving the throttle valve. The throttle valve is drivingly connected to an electric motor via a power transmission member (gear or the like). The throttle valve is connected to a return spring. The return spring always exerts an elastic force in such a direction that the throttle valve blocks the intake passage. Then, when power is supplied to the electric motor, the target opening of the throttle valve is set based on the depression amount of an accelerator pedal provided in the cabin of the vehicle, the engine speed, and the vehicle speed. The opening of the throttle valve is detected by an opening sensor, and the electric motor is driven so that the throttle valve reaches the target opening. When the opening of the throttle valve reaches the target opening, the electric motor maintains the opening of the throttle valve by maintaining the current amount at that time.
[0004]
[Problems to be solved by the invention]
By the way, as shown in FIG. 4, the torque characteristics of the throttle valve device include a required torque T2 for changing the throttle valve from the closed state to the open state due to friction of the power transmission member and the elastic force T1 of the return spring. There is a so-called hysteresis in which a difference occurs from the required torque T3 for changing from the state to the closed state. Therefore, when the throttle valve is held at the target opening, it is necessary to supply a drive current to the electric motor so as to generate the required torque T2, which increases power consumption and increases the temperature of the electric motor. There was a problem.
[0005]
SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide a throttle valve device capable of reducing the power consumption of an electric motor and a control method thereof.
[0006]
[Means for Solving the Problems]
In order to solve the above problem, the invention according to claim 1 includes a throttle valve that adjusts the amount of air passing through an intake passage and a biasing member that biases the throttle valve so as to close the intake passage. A throttle valve device comprising: an electric motor that drives the throttle valve; and a control unit that controls an amount of current supplied to the electric motor, wherein the control unit includes an electric motor for maintaining an opening of the throttle valve. The gist is to control the amount of current supplied to the motor to a value near the minimum amount of current required to maintain the opening of the throttle valve.
[0007]
According to a second aspect of the present invention, in the throttle valve device according to the first aspect, the control unit reduces an amount of energizing current of the electric motor, stores a current amount of energizing current, and stores the stored energizing current. The gist is that the current is controlled to the amount of electric current.
[0008]
According to a third aspect of the present invention, in the throttle valve device according to the first or second aspect, the control unit reduces an energizing current amount of the electric motor and an energizing current amount immediately before or immediately after the throttle valve moves. The main point is that the amount of energizing current of the electric motor is controlled so as to maintain the opening of the throttle valve based on the stored amount of energizing current.
[0009]
According to a fourth aspect of the present invention, in the throttle valve device according to any one of the first to third aspects, the amount of current supplied to the electric motor for controlling the opening degree of the throttle valve is maintained, The gist of the present invention is to provide a minimum amount of current for maintaining the throttle valve at the opening.
[0010]
According to a fifth aspect of the present invention, there is provided a method of controlling a throttle valve device comprising a throttle valve for opening and closing an amount of air passing through an intake passage, and an electric motor for driving the throttle valve. The amount of energizing current of the electric motor for maintaining the opening is the amount of energizing current for maintaining the opening of the throttle valve, which is necessary to bring the throttle valve from the open state to the closed state. The gist is that the control is performed so as to be a value close to the minimum energizing current of the electric motor.
[0011]
According to a sixth aspect of the present invention, there is provided a method for controlling a throttle valve device comprising: a throttle valve for controlling opening and closing of an amount of air passing through an intake passage; and an electric motor for driving the throttle valve. The amount of energizing current is gradually reduced, the amount of energizing current before or after the throttle valve starts moving is stored, the opening of the throttle valve is made to coincide with the target opening, and the amount of energizing current at the time of the coincidence is made The gist of the present invention is that the current is reduced based on the stored current amount.
[0012]
(Action)
According to the first aspect of the present invention, it is possible to suppress the amount of current supplied to the electric motor required to maintain the opening of the throttle valve to a value near the minimum amount of current supplied.
[0013]
According to the second aspect of the invention, the amount of current supplied to the electric motor for maintaining the opening of the throttle valve is gradually reduced, and the amount of supplied current is stored. It is possible to eliminate waste of electric current.
[0014]
According to the third aspect of the present invention, the amount of current supplied to the electric motor is reduced based on the stored amount of supplied current, so that the amount of current supplied to the electric motor is not wasted.
[0015]
According to the invention described in claim 4, it is possible to set the amount of current supplied to the electric motor to the minimum amount of supplied current, thereby suppressing power consumption of the electric motor.
According to the fifth aspect of the present invention, it is possible to provide a control method for reducing the amount of current supplied to the electric motor for maintaining the opening of the throttle valve.
[0016]
According to the invention described in claim 6, it is possible to provide a control method for reducing the amount of current supplied to the electric motor for maintaining the opening of the throttle valve based on the stored amount of supplied current.
[0017]
BEST MODE FOR CARRYING OUT THE INVENTION
(1st Embodiment)
Hereinafter, a first embodiment of the present invention will be described with reference to the drawings.
[0018]
FIG. 1 shows a throttle valve device 1 mounted on an automobile engine. The throttle valve device 1 has a throttle actuator 2 and a control unit 3.
[0019]
The throttle actuator 2 has a throttle body 4. An intake passage 5 is formed in the throttle body 4, and a throttle valve 6 is provided in the intake passage 5. An electric motor 7 for driving a throttle valve 6 is provided in the throttle body 4, and the electric motor 7 and the throttle valve 6 are drivingly connected by a power transmission member 8. Further, a return spring 9 that biases the throttle valve 6 to close the intake passage 5 is provided in the throttle body 4. The throttle body 4 is provided with an opening sensor 10 that outputs a detection signal corresponding to the opening of the throttle valve 6.
[0020]
The throttle valve 6 is fixed to a rotating shaft 11 supported on the throttle body 4 so as to be integrally rotatable.
The output shaft 12 of the electric motor 7 is drivingly connected to the rotating shaft 11 via the power transmission member 8. The power transmission member 8 has a pinion 13 and a reduction gear 14. One end of a return spring 9 is locked to the rotating shaft 11, and the other end of the return spring 9 is locked to the throttle body 4.
[0021]
The electric motor 7 and the opening sensor 10 are connected to the control unit 3, and a detection signal S 1 from the opening sensor 10 is input to the control unit 3. The control unit 3 also receives an accelerator signal S2 based on the amount of depression of an accelerator pedal (not shown) provided in the cabin of the vehicle, an engine speed S3, and a vehicle speed signal S4.
[0022]
The control unit 3 controls the amount of current supplied to the electric motor 7 based on the signals S1 to S4. Specifically, the control unit 3 calculates a target opening of the throttle valve 6 to supply a desired amount of air to the engine based on each of the signals S2 to S4 (or at least one signal). Then, the control unit 3 detects (calculates) the opening of the throttle valve 6 based on the detection signal S1 from the opening sensor 10, and turns on the electric motor 7 so that the opening coincides with the target opening. The flow rate is controlled.
[0023]
In this embodiment, the control unit 3 controls the amount of current supplied to the electric motor 7 by a PWM method. That is, the control unit 3 controls the energization duty ratio (the ratio of the pulse width to the period of the pulse signal) to change the amount of energization current to the electric motor 7.
[0024]
The control unit 3 executes a well-known main program and an energization amount adjustment program shown in FIG. 2, and these are stored in a memory provided in the control unit 3.
[0025]
The control unit 3 executes the main program, changes the amount of current supplied to the electric motor 7, and matches the opening of the throttle valve 6 with the target opening. Then, the control unit 3 executes the energization amount adjustment program shown in FIG. 2, reduces the energization current amount of the electric motor 7 to a value near the minimum energization current amount, and maintains the opening of the throttle valve 6 (target opening amount). Hold each time). The minimum energizing current amount of the energizing current amount is a current amount that generates a torque necessary to maintain the throttle valve 6 at the target opening degree against the elastic force T1 of the return spring 9, and the necessary torque is shown in FIG. 4 corresponds to the required torque T3. However, since the energizing current is changed by controlling the energizing duty ratio in a stepwise manner, the energizing current is not always controlled to be equal to the minimum energizing current. That is, the amount of energizing current is controlled to a value near the minimum energizing current. That is, in order to change the valve opening of the throttle valve 6 from the closed state to the open state, the amount of current supplied to the electric motor 7 must be controlled so as to generate the required torque T2. The amount of current supplied to the electric motor 7 is controlled so as to generate a substantially required torque T3 for holding the valve 6. Therefore, the amount of energizing current for maintaining the opening of the throttle valve 6 is smaller than in the conventional example.
[0026]
Hereinafter, a method of controlling the throttle valve device 1 by the control unit 3 (a program for controlling the amount of electricity) will be described with reference to the flowchart shown in FIG.
In step 101, the control unit 3 determines whether or not the opening of the throttle valve 6 has reached the target opening. When the control unit 3 determines that the opening of the throttle valve 6 has reached the target opening, the process proceeds to step 103, and when the control unit 3 determines that the opening of the throttle valve 6 has not reached the target opening, the process returns to the main program. .
[0027]
In step 103, the control unit 3 checks whether or not the opening of the throttle valve 6 is in the stop holding state. The stop holding state refers to a state in which the throttle valve 6 maintains its opening degree for a predetermined time. When the control unit 3 determines that the opening of the throttle valve 6 is in the stop holding state, the process proceeds to step 105, and when the control unit 3 determines that the opening of the throttle valve 6 is not in the stop holding state, the process returns to the main program.
[0028]
In step 105, the control unit 3 checks whether the control flag is 0 (zero). It is assumed that the control flag is 0 in the initial state. When the control unit 3 determines that the control flag = 0, the process proceeds to step 106.
[0029]
The control flag is used for discriminating between detecting a required minimum amount of current and controlling the detected opening amount of the throttle valve 6 to the required minimum amount of current. That is, the control unit 3 first obtains the necessary minimum amount of current, and then drives the electric motor 7 with the obtained amount of current. For this reason, the electric motor 7 is driven with the minimum necessary current amount at each time according to the opening degree of the throttle valve 6, so that the electric motor 7 is hardly affected by a change with time or the like.
[0030]
In step 106, the control unit 3 sets the control flag = 1, and proceeds to the next step 107.
In step 107, the control unit 3 stores the amount of current A flowing through the electric motor 7, and proceeds to the next step 108.
[0031]
In step 108, the control unit 3 obtains the amount of energizing current B obtained by subtracting the amount of energizing current A energizing the electric motor 7, and sets the energizing current B in the next step 109, ie, Control so as to energize. It should be noted that the control unit 3 controls the amount of energizing current by changing the energizing duty ratio. That is, in step 108, the control unit 3 supplies the electric current B to the electric motor 7 by subtracting 1% from the duty ratio of the electric current A to obtain a new duty ratio. That is, in step 109, the control unit 3 reduces the torque generated in the electric motor 7 and decreases the opening holding force of the throttle valve 6. Then, the process proceeds to the next step 110.
[0032]
In step 110, the control unit 3 determines whether or not the opening of the throttle valve 6 is maintained without moving to the closing side. When the control unit 3 determines that the throttle valve 6 has not moved, it returns to step 107, and when it determines that the throttle valve 6 has moved to the closing side, returns to the main program. That is, the control from step 107 to step 110 is repeated so that the amount of current supplied to the electric motor 7 is reduced until the opening of the throttle valve 6 moves to the closing side. Then, when the throttle valve 6 moves, the control unit 3 stores the amount of current flowing immediately before the throttle valve 6 moves to the closing side, that is, the minimum amount of current C.
[0033]
On the other hand, when the control unit 3 determines that the control flag = 1 in step 105, the process proceeds to step 112. The process proceeds to step 112 after the required minimum amount of current to be supplied to the electric motor 7 has already been obtained.
[0034]
In step 112, the control unit 3 sets the control flag from 1 to 0. In other words, the control flag is set to 0, and preparation is made for the next adjustment of the opening of the throttle valve 6. Then, the process proceeds to the next step 113.
[0035]
In step 113, the control unit 3 reads the minimum energizing current amount C stored in step 107 and sets the minimum energizing current amount C to energize the electric motor 7. Thereafter, the process proceeds to step 111, where the control unit 3 performs main control. In this way, the control unit 3 controls the amount of current supplied to the electric motor 7 to be minimized. That is, the power consumption of the electric motor 7 can be reduced, and the temperature rise of the electric motor can be suppressed accordingly.
[0036]
As described above, according to the present embodiment, the following effects are obtained.
(1) The throttle valve device 1 has a control unit 3 which is controlled by the control unit 3 so that the amount of current supplied to the electric motor 7 is minimized. Therefore, power consumption of the electric motor 7 can be suppressed to a minimum, and a rise in the temperature of the electric motor 7 can be avoided.
[0037]
(2) The control unit 3 stores the minimum energizing current amount C to energize the electric motor 7 in step 107. Therefore, when the target opening of the throttle valve 6 is set to the same condition, there is no waste in the amount of current supplied to the electric motor 7 and power consumption can be reduced.
[0038]
Note that the embodiment of the present invention may be modified as follows.
In the above-described embodiment, the control unit 3 causes the electric motor 7 to supply the minimum energizing current amount C stored in step 107, but gradually increases from the energizing current amount A set in the main to the stored minimum energizing current amount C. You may make it lower.
[0039]
In the above embodiment, the control unit 3 determines whether or not the minimum energizing current amount C is stored by determining whether the control flag is 0 or 1 in step 105. However, the determination is not limited to this, and another method may be used. For example, after setting the minimum energizing current amount C in step 113, the stored minimum energizing current amount C is set to, for example, 0. Then, in step 105, the control unit 3 may perform control so that the process proceeds to step 106 or step 112 depending on whether the stored current amount is 0 or not. In this way, the control unit 3 does not need to consider steps related to the control flag, and can control the throttle valve device 1 smoothly.
[0040]
(2nd Embodiment)
Hereinafter, a second embodiment of the present invention will be described with reference to the drawings. The present embodiment and the first embodiment differ from each other only in the control method of the control unit 3 for the throttle valve device 1. Therefore, only the different parts will be described for convenience of explanation, and the mechanical configuration of the throttle valve device 1 will be described. Is omitted.
[0041]
FIG. 3 shows a control method of the throttle valve device 1 by the control unit 3 of the present embodiment.
In steps 131 to 136 and step 142, the control unit 3 executes substantially the same processing as steps 101 to 106 and step 112 in FIG.
[0042]
In step 137, the control unit 3 subtracts the amount of current D flowing through the electric motor 7 from the amount of current E, and sets the subtracted amount of current E in step 138, that is, Control so as to energize. That is, as in the first embodiment, the duty ratio of the electric motor 7 is decremented by 1% to control the amount of current supplied to the electric motor 7 to be reduced. That is, in step 138, the control unit 3 reduces the force for holding the opening of the throttle valve 6 by the electric motor 7. Thus, the process proceeds to the next step 139.
[0043]
In step 139, the control unit 3 performs substantially the same processing as step 110 in FIG. That is, the control unit 3 reduces the amount of current supplied to the electric motor 7 until the opening of the throttle valve 6 moves to the closing side.
[0044]
In step 140, the control unit 3 stores the amount of current E subtracted in step 137, moves to the next step 141, and performs main control.
[0045]
In step 143, the control unit 3 subtracts the amount of current F applied to the electric motor 7 from the amount of current G supplied. Note that the subtraction of the current flow amount F from the current flow amount F in step 143 is performed by reducing the duty ratio by 1%, as in step 137. Then, the process proceeds to the next step 144.
[0046]
In step 144, the control unit 3 compares the energizing current amount G subtracted in step 143 with the energizing current amount E stored in step 140. When the control unit 3 determines that the subtracted energizing current G is larger than the stored energizing current E (G> E), the control unit 3 proceeds to the next step 145 and the stored energizing current E is greater than the subtracted energizing current G ( If G <E), the process returns to the main program.
[0047]
In step 145, the control unit 3 causes the electric motor 7 to supply the supplied current G subtracted in step 143. Then, the process returns to step 143, and control is performed so as to further reduce the supplied current amount G again. That is, the control unit 3 gradually reduces the amount of current supplied to the electric motor 7 to the minimum amount of current required for maintaining the opening of the throttle valve 6. Accordingly, since the same operation as when the minimum amount of current is detected is performed, the opening of the throttle valve 6 can be reliably maintained.
[0048]
In this way, the control unit 3 controls the amount of current supplied to the electric motor 7 to be minimized. That is, the power consumption of the electric motor 7 can be reduced, and the temperature rise of the electric motor can be suppressed accordingly.
[0049]
As described above, according to the present embodiment, the following effects are obtained in addition to the effects of the first embodiment.
(1) In step 140, the control unit 3 stores the amount of current E when the throttle valve 6 is moved to the closing side. Therefore, the electric motor 7 may be supplied with a current G that is larger than the current E. That is, the control unit 3 can easily control the amount of current supplied to the electric motor 7 to be minimized.
[0050]
(2) In step 139, the control unit 3 controls so as to store the current amount E after the opening of the throttle valve 6 moves to the closing side. Therefore, the control unit 3 does not need to store the current value E subtracted in step 137 every time, and the control becomes smooth.
[0051]
Note that the embodiment of the present invention may be modified as follows.
In the above-described embodiment, in step 143, the energizing current amount F energizing the electric motor 7 is subtracted by 1% in duty ratio, but the energizing current amount E stored in step 138 is larger by 1% than the energizing current amount E. May be controlled in advance.
[0052]
In the above embodiments, the control unit 3 subtracts 1% from the duty ratio of the electric motor 7 to reduce the amount of current to be supplied. However, the duty ratio may be subtracted from values other than 1%. For example, by subtracting 0.1%, the power consumption of the electric motor 7 can be reduced as compared with the present embodiment.
[0053]
In the above embodiments, the duty ratio is reduced as the subtraction method. However, another method may be used as long as the amount of current supplied to the electric motor 7 is reduced.
The technical ideas that can be grasped from the above embodiments are described below.
[0054]
(A) The throttle valve device according to claim 3, wherein the control unit controls the presence or absence of the stored energizing current by a control flag. This makes it possible to easily determine the presence or absence of the stored current amount. That is, when the current is stored, the amount of the supplied current is used, and when not stored, the supplied current can be easily determined and controlled so as to reduce the supplied current.
[0055]
(B) In the throttle valve device according to claim 1 or 2, the control unit performs control so as to store the amount of current supplied to the electric motor when the opening of the throttle valve cannot be maintained. A throttle valve device characterized by the above-mentioned. With this configuration, the amount of current supplied when the opening of the throttle valve cannot be maintained can be stored, so that the same effects as those of the present invention can be obtained.
[0056]
(C) In the throttle valve device described in (b), the control unit sets the amount of energizing current larger than the stored amount of energizing current in advance and controls the electric motor to energize. Throttle valve device. Even in this case, the same effects as those of the present invention can be obtained.
[0057]
【The invention's effect】
As described in detail above, according to the present invention, it is possible to provide a throttle valve device capable of reducing the power consumption of an electric motor and a control method thereof.
[Brief description of the drawings]
FIG. 1 is a schematic diagram of a throttle valve device.
FIG. 2 is a flowchart showing a control method of a throttle valve device.
FIG. 3 is a flowchart showing a control method of the throttle valve device.
FIG. 4 is an explanatory diagram showing the relationship between the amount of current supplied to the electric motor and the opening of a throttle valve.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Throttle valve device, 2 ... Throttle actuator, 3 ... Control unit, 5 ... Intake passage, 6 ... Throttle valve, 7 ... Electric motor, 8 ... Power transmission member, 9 ... Return spring as urging member, 10 ... Open Degree sensors, A, B, D, E, F, G: energizing current, C: minimum energizing current.

Claims (6)

A throttle valve for opening and closing the amount of air passing through the intake passage;
An urging member for urging the throttle valve so as to close the intake passage;
An electric motor that drives the throttle valve;
A throttle valve device comprising: a control unit that controls an amount of current supplied to the electric motor;
The control unit controls the amount of current supplied to the electric motor for maintaining the opening of the throttle valve to a value near the minimum amount of current required for maintaining the opening of the throttle valve. And the throttle valve device. The throttle valve device according to claim 1,
The throttle valve device, wherein the control unit reduces the amount of current supplied to the electric motor, stores the amount of current supplied at each time, and controls the amount of supplied current. The throttle valve device according to claim 1 or 2,
The control unit reduces the amount of current flowing through the electric motor, stores the amount of current flowing immediately before or immediately after the throttle valve moves, and maintains the opening of the throttle valve based on the stored amount of current flowing. The amount of current supplied to the electric motor is controlled as described above. The throttle valve device according to any one of claims 1 to 3,
The throttle valve device according to claim 1, wherein the amount of current supplied to the electric motor for controlling the opening of the throttle valve to be maintained is a minimum amount of current supplied for maintaining the throttle valve at the opening. A method for controlling a throttle valve device comprising: a throttle valve that controls opening and closing of an amount of air passing through an intake passage; and an electric motor that drives the throttle valve.
The amount of current supplied to the electric motor for maintaining the opening of the throttle valve is changed to the amount of current supplied for maintaining the opening of the throttle valve from the state in which the throttle valve opens the intake passage. A control method for a throttle valve device, wherein the control is performed so as to be a value close to a minimum amount of current supplied to the electric motor necessary for the above. A method for controlling a throttle valve device comprising: a throttle valve that controls opening and closing of an amount of air passing through an intake passage; and an electric motor that drives the throttle valve.
The amount of energizing current of the electric motor is gradually reduced, the amount of energizing current before or after the throttle valve starts moving is stored, and the opening of the throttle valve is made to coincide with the target opening. A method for controlling a throttle valve device, wherein the amount of electric current is reduced based on the stored amount of supplied current.

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