JP2712748B2 - Initialization method of DC motor type positioning device for variable intake control valve - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a DC motor type positioning apparatus for driving an intake control valve, which varies the effective passage length of an intake system of an internal combustion engine, with a DC motor. The present invention relates to a method for initializing a DC motor type positioning device for a variable intake control valve for initializing a valve.

(Prior Art) This type of variable intake control valve DC motor type positioning device is incorporated in a so-called variable intake system of an internal combustion engine.

In this variable intake system, the length of the intake system of the internal combustion engine is varied by opening and closing a variable intake control valve. More specifically, in the middle of the main intake passage,
A variable intake control valve is provided, and a bypass intake passage is provided in the main intake passage so as to bypass the variable intake control valve. Therefore, if the engine has the above-described intake system, when the rotational speed of the internal combustion engine is relatively low, the variable intake control valve is closed to increase the effective passage length of the intake system. Is relatively high, by opening the variable intake control valve and shortening the effective passage length of the intake system, it is possible to increase the output of the internal combustion engine over a wide rotational speed range.

The above-described variable intake system incorporates a DC motor-type positioning device for opening and closing a variable intake control valve as an object. The DC motor-type positioning device includes a DC motor and a DC motor. A power transmission path is provided for connecting between the output shaft of the motor and the variable intake control valve. Accordingly, the DC motor type positioning device can drive the variable intake control valve to open and close by driving the DC motor.

In addition, the DC motor type positioning device includes a rotation speed sensor that alternately outputs an ON signal and an OFF signal in accordance with the rotation of the DC motor and a rotation shaft included in the power transmission path, and a control that controls the driving of the DC motor. The control circuit counts the output signal from the rotation speed sensor, that is, the ON and OFF signals, to determine the actual valve opening degree of the variable intake control valve, and The drive of the DC motor is controlled so that the degree matches the target valve opening.

The above-described DC motor type positioning device is not only obtained at a lower cost than a positioning device using a step motor in place of the DC motor, but also detects the actual valve opening of the variable intake control valve by a rotation speed sensor. Therefore, the valve opening of the variable intake control valve can be controlled with high accuracy.

(Problems to be Solved by the Invention) By the way, as is apparent from the above description, in the DC motor type positioning device, the ON / OFF signal from the rotation speed sensor is counted, and the actual valve of the variable intake control valve is measured. The opening is calculated. However, in calculating the actual valve opening, first, the valve opening of the variable intake control valve is set to, for example, an initial position in which the variable opening control valve is set to either the fully open position or the fully closed position. Need to be positioned in That is, by counting the ON and OFF signals of the rotation speed sensor based on the time when the valve opening of the variable intake control valve is at the initial position, the displacement amount of the variable intake control valve from the initial position, The opening can be accurately detected.

For this reason, conventionally, in the above-described DC motor type positioning device, when the operation is first started, the valve opening of the variable intake control valve is reliably positioned at the initial position. The DC motor is driven until the valve body of the valve comes into contact with a stopper that defines its initial position. In this case, the DC motor drive time depends on the actual valve opening of the variable intake control valve. The actual valve opening reaches the initial position without fail, and as a result,
The time is set so that the valve body of the variable intake control valve is kept in contact with the stopper.

However, in the above-described initialization method of the DC motor type positioning device, when the initialization is performed, if the actual valve opening of the variable intake control valve is near the initial position, the valve body already hits the stopper. Despite being in contact,
Since the DC motor is driven for a long time, the load on the DC motor becomes large, and the DC motor may be seized and may be damaged.

The present invention has been made based on the above-described circumstances, and an object of the present invention is to carry out initialization without needlessly driving a DC motor and moving a variable intake control valve to its initial position. It is an object of the present invention to provide a method of initializing a DC motor type positioning device for a variable intake control valve, which can reliably position the DC motor at a fully closed position and prevent the DC motor from being damaged.

(Means for Solving the Problems) The present invention is applied to a DC motor type positioning device for a variable intake control valve of the type described above, and in the initialization method, the control operation of the DC motor type positioning device is first started. Then, a driving step of driving the DC motor for a fixed time is performed, and the actual valve opening of the variable intake control valve is directed toward a stopper that defines a fully closed position as an initial valve opening of the variable intake control valve. When the on / off signal from the rotation speed sensor is inverted during the driving process, the driving process is repeatedly performed from the beginning.On the other hand, when the on / off signal from the rotation speed sensor is not inverted during the driving process, It is determined that the initialization of the DC motor type positioning device has been completed without performing the driving process again.

(Operation) According to the initial method of the present invention, the DC motor is driven for a fixed time until the on / off signal from the rotation speed sensor is no longer inverted, that is, until the variable intake control valve comes into contact with the stopper. Position the valve in its fully closed position, which is its initial valve opening.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 shows an internal combustion engine for a vehicle provided with a variable intake system, which is, for example, a V-type 6-cylinder gasoline engine. A main intake passage 2 and an exhaust passage 3 are connected to each combustion chamber 1 of the internal combustion engine, respectively, and each of the main intake passage 2 and the exhaust passage 3 is connected to the combustion chamber 1 so as to face the combustion chamber 1. 4 and exhaust valve 5
Is arranged.

An air cleaner 6, a throttle valve 7, and an injector 8 are sequentially arranged in the main intake passage 2 from the upstream side, and a three-way catalytic converter 9 and a muffler (not shown) are arranged in the exhaust passage 3 from the upstream side. Are arranged in order. In the main intake passage 2, a part located downstream of the throttle valve 7 is a surge tank 10.
Further, the injectors 8 are provided in the intake manifold portion of the main intake passage 2 for each cylinder.

Although not shown, the throttle valve 7 is connected to an accelerator pedal in the vehicle cabin via an accelerator wire or the like, whereby the opening degree of the throttle valve 7 can be varied according to the amount of depression of the accelerator pedal. It has become so.

The variable intake system includes a variable intake control valve 11 located immediately downstream of the surge tank 10 in the main intake passage 2, and a bypass intake passage that bypasses both the variable intake control valve 11 and the surge tank 10. It has 12 and. When the variable intake control valve 11 is in the fully closed position shown by the solid line in FIG. 1, the intake air passes from the main intake passage 2 via the bypass intake passage 12 and returns to the main intake passage 2 again. Through the combustion chamber 1. On the other hand, when the variable intake control valve 11 is at the fully open position indicated by the broken line in FIG.
Instead of passing through the detour intake passage 12, the combustion chamber 1 reaches the combustion chamber 1 through a short intake path including only the main intake passage 2.

Here, the valve body of the variable intake control valve 11 can rotate between the fully open position and the fully closed position, and when the valve body reaches the fully open position and the fully closed position, the valve body is not shown. It comes into contact with the stopper.

The above-described variable intake system incorporates a DC motor type positioning device for controlling the opening degree of the variable intake control valve 11, and the positioning device will be described below.

First, the positioning device is a DC motor, that is, a DC motor.
The DC motor 13 includes a small DC motor with a brush. As shown in FIG. 2, the DC motor 13 is accommodated in the main intake passage 2 in a casing 14 attached to an outer wall near the variable intake control valve 11.

The output shaft 15 of the DC motor 13 is connected to the variable intake control valve 11 via a power transmission path 16. That is, the power transmission path 16 includes a gear 17 attached to the output shaft 15 of the DC motor 13, and a gear 19 meshed with the gear 17 via the intermediate gear 18. The gear 19 is mounted on a rotating shaft 20, which is rotatably supported in the casing 14 via several bearings 21.

A worm gear 22 is attached to one end of the rotating shaft 20, and a worm wheel 23 is attached to the worm gear 22.
Are engaged. The worm wheel 23 is attached to a valve shaft 24 of the variable intake control valve 11 (see FIG. 1).

Therefore, if the DC motor 13 and the variable intake control valve 11 are connected by the power transmission path 16 described above, the DC motor 13 is driven to rotate the valve shaft 24 of the variable intake control valve 11. Accordingly, the opening degree of the variable intake control valve 11 can be varied between the fully open position and the fully closed position.

Further, a pair of rotation speed sensors, that is, first and second rotation speed sensors 25 and 26 are arranged on the other end side of the rotation shaft 20. These first and second rotation speed sensors 25, 26
As shown in FIGS. 3 and 4, respectively, these rotational speed sensors have basically the same structure, and therefore, only the first rotational speed sensor 25 will be described here.

The first rotation speed sensor 25 includes a ring magnet 27a fixed to the peripheral surface of the rotation shaft 20. This ring magnet 27a is attached to the rotating shaft 20 via a sleeve 28 made of a non-magnetic material, or by forming the rotating shaft 20 from a non-magnetic material,
It can be directly attached to the rotating shaft 20. As shown in FIG. 3, the ring magnet 27a has one half circumferential surface magnetized to the N pole and the other half circumferential surface magnetized to the S pole. Note that, in FIG.
The boundary of the magnetic pole at a is indicated by a broken line X so as to be clear. A magnetic probe 29a made of a Hall IC is disposed near the outer peripheral surface of the ring magnet 27a so as to always face the outer peripheral surface. The magnetic probe 29a outputs a signal corresponding to the magnetic pole of the ring magnet 27a when the ring magnet 27a is rotated together with the rotating shaft 20. That is, when the ring magnet 27a rotates with respect to the magnetic probe 29a, the magnetic probe 29a detects a different magnetic pole every half rotation of the ring magnet 27a, and thus, for example, when detecting the N pole of the ring magnet 27a. , The magnetic probe 29a is turned on and
When a level signal is output and the S pole of the ring magnet 27a is being detected, the magnetic probe 29a is turned off and outputs an H level signal. Accordingly, with the rotation of the rotating shaft 20, the signal from the magnetic probe 29a, that is, the signal from the first rotation speed sensor 25, is turned on and off as shown by P1 in FIG. Will be.

Since the second rotation speed sensor 26 has the same structure as the first rotation speed sensor 25 as described above,
Members having the same functions as the members of the rotation speed sensor 25 are denoted by the same reference numerals in which only the suffix is replaced by b, and the description thereof will be omitted, and only different points will be described below.

In the case of the second rotational speed sensor 26, as is apparent from a comparison between FIG. 3 and FIG.
The rotation angle phase of the attachment to 0 is different from that of the ring magnet 27a in the first rotation speed sensor 25 by 90 °. Therefore, the output of the ON signal and the OFF signal from the magnetic probe 29b, that is, the second rotation speed sensor 26 is indicated by P2 in FIG.
It becomes what is shown by.

The signals from the first and second rotation speed sensors 25 and 26 are
As shown in the figure, an electronic control unit 30 is provided as a control circuit for controlling the drive of the DC motor 13, and the electronic control unit 30 includes an engine speed sensor 31, Air flow sensor 32, throttle sensor,
Atmospheric pressure sensor, intake air temperature sensor, an idle switch, O ₂ sensor, a high temperature sensor, a knock sensor, a water temperature sensor, so that the signal from the TDC sensor, and the like are also inputted.
FIG. 1 shows only the engine speed sensor 31 and the air flow sensor 32 among these various sensors, and the first and second rotational speed sensors also have the magnetic probe 29a. Only is shown.

As shown schematically in FIG. 6, the electronic control unit 30 includes an actual valve opening detection unit 33 to which signals from the first and second rotation speed sensors 25 and 26 are input, and an engine speed sensor. The target valve opening setting unit 34 to which a signal from the input unit 31 is input, the actual valve opening detecting unit 33, the target valve opening setting unit 34, and the airflow sensor 32 are respectively connected to control the driving of the DC motor 13. And a control unit 35 that outputs a control signal. Note that the engine speed sensor 31 may be also used as a crank angle sensor that detects the crank angle of the internal combustion engine.

Next, the operation control of the variable intake system will be described with reference to the flowcharts shown in FIGS.

When the internal combustion engine is started by being turned on by an ignition key, initial values are set in step S1.
In this initial value setting, various flags, for example, initialization flags are reset to 0.

Then, from the next step, initialization of the DC motor type positioning device, that is, initialization processing is performed,
First, in step S2, it is determined whether the battery voltage VB of the DC motor 13 is equal to or higher than a predetermined value V1. If the determination here is negative (N), the process proceeds to step S9, and in this step S9, it is determined whether or not the above-described initialization flag is set to 1. In this case, the initialization flag remains reset to 0 in the previous step S1, and in this case, the determination result is NO (N). Therefore, step S10 is bypassed from step S9 to step S11, where it is also determined whether or not the initialization flag is set to 1 again. Since the determination here is also negative (N), the process returns from step S11 to step S2, and step S2 is performed again. As a result, step S2
Unless the judgment in (1) is positive (Y), that is, DC motor
If the battery voltage VB of the thirteen is not higher than the predetermined value V1, the DC motor type positioning device will not operate at all.

When the determination in step S2 is positive (Y), the next step S3 is performed, and in this step S3, a predetermined time T is set in the initialization timer. here,
The initialization timer determines the battery voltage VB of the DC motor 13.
Is a subtraction timer that operates only when is equal to or greater than V1.In this case, the predetermined time T is, in the case of this embodiment, the valve opening of the variable intake control valve 11 is set to the fully open position and the fully closed position. The time is set to be sufficiently shorter than the time required to change between the two.

In the next step S4, the DC motor 13 is driven to rotate in one direction, that is, a driving step of the variable intake control valve 11 is performed to change the valve opening of the variable intake control valve 11 toward the fully closed position. . While such a driving process is being performed, in the next step S5, it is determined whether or not the output signal from the rotation speed sensor, in this case, the first rotation speed sensor 25 is inverted, that is, the first rotation speed sensor. It is determined whether the output signal from 25 has been inverted from an ON signal to an OFF signal or from an OFF signal to an ON signal. If the determination here is positive (Y), since the DC motor 13 is still actually driving, the process returns to step S2, and the above-described steps are repeatedly performed. That is, while the DC motor 13 is actually driven, the above-described driving process is repeatedly performed.

However, when the determination in step S5 is negative (N), that is, when the driving process is being performed,
If the output signal from the first rotation speed sensor 25 is not inverted, it is determined in the next step S6 whether or not the initialization timer has reached zero. If the determination is negative (N), in step S12, it is determined whether the battery voltage VB of the DC motor 13 is maintained at V2 or higher.
If the determination is positive (Y), the process returns to step S4,
The steps after this step are repeatedly performed. That is, the DC motor 13 is driven to rotate in one direction until the determination in step S6 becomes positive (Y).

However, when the DC motor 13 is rotating,
In other words, before the driving process described above is completed, the DC motor 13
If the battery voltage VB falls below V2, which is lower than V1 by a predetermined value, the determination in step S12 is negative (N),
It returns to step S2. Therefore, in this case, the rotation drive of the DC motor 13 is interrupted, and the countdown by the initialization timer is also stopped at the same time.

When the battery voltage VB of the DC motor 13 reaches V1 or more again, steps after step S3 are performed.

The predetermined time T1 set in the initialization timer is satisfied without the determination in step S12 being negative (N) and the determination in step S5 being positive (Y).
In this case, even if the DC motor 13 is to be driven, the rotation of the DC motor 13 is not actually performed, so that the valve opening of the variable intake control valve 11 is already in the fully closed position. Then, it can be determined that the valve element is in a state of contact with the stopper that defines the fully closed position. Therefore, in this case, the determination in step S6 becomes positive (Y), and the process proceeds to the next step S7. At this point, the rotational drive of the DC motor 13 is stopped, and in step S7, The initialization flag is set to 1, thereby determining that the initialization of the DC motor type positioning device has been completed.

Thereafter, by executing steps S7 to S8, the valve opening of the variable intake control valve 11 is set to its initial value of 0.

The above-described initialization processing of the DC motor type positioning apparatus is schematically shown in a time chart of FIG. As is clear from FIG. 9, in the initialization process of this embodiment, the DC motor 13 is driven in one direction, ie, in the same direction as the ignition key is turned on, provided that the battery voltage VB of the DC motor 13 is equal to or higher than V1. At the same time, the variable intake control valve 11 is rotationally driven toward the fully closed position, and at the same time, a predetermined time T is set in the initialize timer, and the above-described driving process is performed. During such a driving process, when the battery voltage VB of the DC motor 13 becomes V2 or less, the driving of the DC motor 13 and the subtraction by the initialization timer are stopped until the battery voltage VB becomes V1 or more again. In addition, when the output signal from the first rotation speed sensor 25 is inverted during the driving process, it is understood that the driving process is repeatedly performed. Further, during one driving step, when the output signal from the first rotation speed sensor 25 is not inverted and the initialization timer becomes 0, the rotation driving of the DC motor 13 is stopped and the initialization of the positioning device is started. Processing will be completed.

Next, the process proceeds from step S8 to step S9, in which it is determined whether or not the initialization flag is set to "1". As described above, when the initialization processing of the positioning device is completed, since the initialization flag has already been set to 1 in step S7, the determination is positive (Y) in this case, and Then, the next step S10 is performed.

In step S10, target valve opening control of the variable intake control valve 11 is performed. The target valve opening control will be briefly described. In the actual valve opening detector 33 of the electronic control unit 30, the variable intake control valve 11 is controlled based on signals from the first and second rotation speed sensors 25 and 26. The actual valve opening is detected and the control
Immediately after the control operation of the variable intake system is started, that is, immediately after the above-described initialization processing of the DC motor type positioning device is performed, the actual intake valve of the variable intake control valve 11 is opened. The degree is in the fully closed position.

In the target valve opening setting section 34, a target valve opening of the variable intake control valve 11 is set based on a signal from the engine speed sensor 31, and the target valve opening is also set in the control section 35. Supplied to Here, the target valve opening is determined from the map shown in FIG. 10 or a function defining this map. As is clear from FIG. 10, the target valve opening of the variable intake control valve 11 is fully closed when the engine speed of the internal combustion engine is in a low speed range below a low speed value N1 (for example, around 3500 rpm), and the engine speed is reduced. Low speed value N1
It is set to be fully open in the high speed range higher than the high speed value N2 (for example, around 4500 rpm), and the low speed value
In the transition region between N1 and the high speed value N2, the valve opening is set to gradually increase from fully closed to fully open as the engine speed increases.

Therefore, in the case of this embodiment, in the initialization process of the DC motor type positioning device, the variable intake control valve 11 is positioned at the fully closed position. As a result, the startability of the internal combustion engine is improved.

Then, when the actual valve opening degree and the target valve opening degree of the variable intake control valve 11 are obtained by the actual valve opening degree detecting section 33 and the target valve opening degree setting section 34, these are determined by the control section 35. Are compared,
Then, a drive control signal is output from the control unit 35 to the DC motor 13 so that the actual valve opening matches the target valve opening.

When the rotating shaft 20 is rotated by the driving of the DC motor 13,
As described above, the valve shaft 24 of the variable intake control valve 11 is rotated, and the actual valve opening changes. On the other hand, with the rotation of the rotation shaft 20, the first and second rotation speed sensors 25, Since a pulse signal as shown in FIG. 5 is output from 26, the actual valve opening detection section 33 counts the number of pulses from at least one of the rotation speed sensors, and The actual valve opening of the variable intake control valve 11 can be constantly calculated based on the closed position, and the drive of the DC motor 13 is stopped when the actual valve opening matches the target valve opening. Will be.

In the case of this embodiment, the rotation shaft 20 is provided with two sensors, the first and second rotation speed sensors 25 and 26,
By comparing the overlapping state of the output patterns from the first and second rotation speed sensors 25 and 26, it is possible to detect whether the DC motor 13 is in the forward rotation state or in the reverse rotation state. This is convenient when the actual valve opening of the variable intake control valve 11 is obtained from addition and subtraction of the number of pulses.

Here, as is clear from the target valve opening characteristic shown in FIG. 10, the actual valve opening of the variable intake control valve 11 is maintained at the fully closed position when the engine speed is equal to or lower than N1. The intake air supplied to the combustion chamber 1 of the internal combustion engine flows through a long effective intake passage via the bypass intake passage 12, whereas when the engine speed is equal to or higher than N2, the variable intake control valve Since the 11 actual valve opening is maintained at the fully open position, the intake air supplied to the combustion chamber 1 of the internal combustion engine flows through the short effective intake passage only through the main intake passage 2. In addition, when the engine speed is between N1 and N2, the actual valve opening of the variable intake control valve 11 is, for example, 1/4 Each time, the actual valve opening is controlled so as to increase.

Accordingly, the output torque of the internal combustion engine is as shown in FIG. 11, and as apparent from FIG. 11, a high output torque can be obtained over the entire range of the engine speed, and the variable intake Fluctuations in output torque when the control valve 11 changes from fully closed to fully opened can be suppressed to a small value.

The present invention is not limited to the above-described embodiment, and various modifications are possible. For example, in one embodiment, the output signal of the first rotation speed sensor 25 is used to determine whether or not the initialization processing has been completed, but the signal may be the output signal of the second rotation speed sensor 26. Alternatively, both output signals from the first and second rotational speed sensors 25 and 26 may be monitored.

In addition, as one of the conditions for performing the initialization process, in one embodiment, the battery voltage VB of the DC motor 13 is equal to or higher than V1 or V2, but the values of V1 and V2 may be the same value. .

Further, the present invention is not limited to a DC motor type positioning device incorporated in a variable intake system. For example, the DC motor type positioning device controls a valve opening of an idle speed control valve of an internal combustion engine. It is needless to say that the initialization method of the present invention can be implemented even when the initialization method is used.

(Effects of the Invention) As described above, according to the initialization method of the DC motor type positioning device for a variable intake control valve of the present invention, the DC motor is driven at regular time intervals, and the fully closed position of the valve opening is set. A driving step of driving the variable intake control valve toward the prescribed stopper is performed. At this time, when the on / off signal from the rotation speed sensor is inverted, the driving step is repeated. If the signal is not determined, the next drive step is not performed, and since it is determined that the initialization of the variable intake control valve has been completed, the variable intake control valve is moved to the stopper that defines its fully closed position. Upon contact, the drive of the DC motor is immediately stopped. Therefore,
Even though the variable intake control valve is in the fully closed position in contact with the stopper, the DC motor is not driven for a long time, and seizure and damage of the DC motor can be reliably prevented. It has excellent effects such as.

[Brief description of the drawings]

The drawings show an embodiment of the present invention. FIG. 1 is a schematic sectional view of an internal combustion engine having a variable intake system, and FIG.
FIG. 3 and FIG. 4 are cross-sectional views showing the configuration of the positioning device, and FIG.
FIG. 6 is a graph showing respective outputs from the first and second rotation speed sensors, FIG. 6 is a block diagram of an electronic control unit,
7 and 8 are flowcharts for explaining a control operation of the variable intake system, FIG. 9 is a time chart schematically showing an initialization process of the positioning device,
FIG. 10 is a graph showing a target valve opening characteristic of the variable intake control valve, and FIG. 11 is a graph showing the relationship between the output torque of the internal combustion engine and the engine speed obtained by the operation of the variable intake system. 2 ... main intake passage, 10 ... surge tank, 11 ... variable intake control valve, 12 ... bypass intake passage, 13 ... DC motor, 16 ...
... power transmission path, 25,26 ... rotation speed sensor, 30 ... electronic control device, 31 ... engine speed sensor.

 ──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-2-56606 (JP, A) JP-A-59-229608 (JP, A) JP-A-63-20509 (JP, A) JP-A-60-1985 11638 (JP, A) JP-A-61-223236 (JP, A) JP-A-59-32162 (JP, U)

Claims (1)

(57) [Claims] 1. A DC motor connected to a variable intake control valve provided in an intake passage of an internal combustion engine and varying an effective passage length of an intake system via a power transmission path, the DC motor and a power transmission path. When the rotating shaft included in is rotated, with the rotation of the rotating shaft, a rotation speed sensor that alternately outputs an ON signal and an OFF signal, and counts ON and OFF signals of the rotation speed sensor, and A control circuit for determining the actual valve opening of the variable intake control valve and controlling the rotation of the DC motor so that the actual valve opening becomes the target valve opening. In this case, when the control operation of the DC motor type positioning device is started for the first time, a driving step of driving the DC motor for a certain period of time is performed, and the actual valve opening of the variable intake control valve is adjusted by the variable intake control valve. As the initial valve opening of Is displaced toward the stopper that defines the fully closed position of the motor, and when the on / off signal from the rotation speed sensor is inverted during the driving process, the driving process is repeatedly performed from the beginning, while the rotation is performed during the driving process. If the on / off signal from the number sensor does not reverse,
A method for initializing a DC motor-type positioning device for a variable intake control valve, wherein it is determined that initialization of a DC motor-type positioning device has been completed without re-executing a driving process.