JP2712750B2 - Drive control method for DC motor type positioning device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drive control method for a DC motor type positioning device that positions an object at a target position using a DC motor as a drive source.

(Prior Art) This type of DC motor type positioning device is applied to various fields. For example, there is a DC motor type positioning device incorporated in a variable intake system of an internal combustion engine.

Here, the variable intake system is configured to vary the effective length of the intake supply path in accordance with the rotational speed in order to increase the output over a wide rotational speed range of the internal combustion engine. . Such a variable intake system includes a variable intake control valve disposed in a main intake passage leading to a combustion chamber of an internal combustion engine, and a bypass intake passage attached to the main intake passage so as to bypass the variable intake control valve. And the valve opening of the variable intake control valve is controlled by a DC motor type positioning device.
It is controlled according to the rotation speed of the internal combustion engine.

That is, the DC motor type positioning device includes a DC motor connected to a variable intake control valve as an object via a power transmission path, and a rotation that detects the rotation speed of a rotating shaft included in the power transmission path from the DC motor. While detecting the actual valve opening of the variable intake control valve based on the signal from the number sensor and the rotational speed sensor, the actual valve opening is compared with a target valve opening set according to the rotational speed of the internal combustion engine. And a control circuit for controlling the driving of the DC motor so that the opening matches the target valve opening.

Here, specifically, when the rotation speed of the internal combustion engine is equal to or lower than a predetermined low speed value, the above-described positioning device sets the valve opening of the variable intake control valve to the fully closed position, thereby allowing the variable intake control valve to pass through the bypass intake passage. By supplying the intake air to the combustion chamber of the internal combustion engine, the intake supply path can be lengthened. On the other hand, when the rotation speed of the internal combustion engine reaches a predetermined high speed value or more, the variable intake control valve is controlled by the positioning device such that the valve opening is at the fully open position. In this case, since the intake air flows only through the main intake passage, the intake supply path is short.

When the rotation speed of the internal combustion engine is between the low speed value and the high speed value, the positioning device changes the valve opening of the variable intake control valve from the fully closed position to the fully open position as the rotation speed of the internal combustion engine increases. , So that the effective length of the intake air supply path can be varied.

(Problems to be Solved by the Invention) In the above-described variable intake system, the allowable displacement range of the valve opening of the variable intake control valve is determined by the range between the fully open position and the fully closed position. Needless to say, the fully open position and the fully closed position are defined by stoppers to which the valve body of the variable intake control valve abuts. Therefore, when the target valve opening of the variable intake control valve is set to the fully open position or the fully closed position, the valve pair of the variable intake control valve
It is driven by the DC motor until it comes into contact with the stopper.

Here, as in the case where the valve opening of the variable intake control valve is positioned from the fully closed position to the fully opened position, the actual valve opening is greatly changed toward the fully opened or fully closed position which is the target valve opening. In such a case, the driving time of the DC motor also inevitably increases. In a state where the DC motor is driven for a long time, the motor speed also increases to reach the maximum speed. Therefore, the driving speed of the valve of the variable intake control valve driven by the DC motor also decreases. It's getting faster. For this reason, when the valve body of the variable intake control valve reaches the fully open or fully closed position, which is the target valve opening, and comes into contact with the stopper, it collides with the stopper with a strong force, The valve body of the variable intake control valve is likely to be damaged. Further, in this case, the DC motor also receives a large load because the rotation of the DC motor is forcibly prevented by the valve body coming into contact with the stopper from a state where the motor speed is high. As a result, the DC motor may be damaged.

The present invention has been made based on the above-described circumstances, and an object thereof is to specify an allowable displacement range of an object and to set an end position formed by a stopper when the target position is set. Even if the target object does not strongly collide with the stopper, the drive control method of the DC motor type positioning device can position the target object at the end position and prevent damage to the target object and the DC motor. Is to provide.

(Means for Solving the Problems) The present invention is connected to an object to be positioned and controlled via a power transmission path, and has a characteristic that the rotation speed increases toward the maximum speed with the passage of time from the start of energization. A DC motor, a rotation speed sensor for detecting the rotation speed of a rotating shaft included in a power transmission path from the DC motor, a stopper for defining an end position of an allowable displacement range of the object, and a signal from the rotation speed sensor. While calculating the actual position of the object based on
In a DC motor type positioning device that compares the actual position with a target position set in accordance with a change in the control input and drives the DC motor so that the actual position matches the target position,
In the drive control method according to the present invention, when the target position of the object is set at the end position, the drive of the DC motor is stopped for a predetermined time when the actual position of the object reaches at least the position immediately before the end position. Thereafter, the DC motor is driven again to position the actual position of the object at the end position which is the target position.

(Operation) According to the drive control method for the DC motor-type positioning device described above, when the target position of the object is the end position, the DC motor is driven when the object reaches the position immediately before the end position. The object is stopped for a predetermined time, and thereafter, the object is gently positioned at the end position which is the target position by re-driving the DC motor.

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. Here, the fully open position and the fully closed position of the variable intake control valve 11 are defined by a stopper (not shown).

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 a half-peripheral surface magnetized to the N-pole and the other half-peripheral surface has S
Magnetized to poles. In addition, in FIG.
The boundary is indicated by a broken line X so that the region of the magnetic pole at 27a is clear. And the ring magnet 27a
A magnetic probe 29a made of a Hall IC is arranged near the outer peripheral surface of the above 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. The magnetic probe 29a is turned on to output an L-level signal, and when detecting the S pole of the ring magnet 27a, 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 including the DC motor type positioning device will be described with reference to the flowcharts shown in FIGS. 7 to 11.

As shown in FIG. 7, when the internal combustion engine is turned on by an ignition key and started, an initial value is set in step S1. In this initial value setting, various flags, for example, X and Y are set. , Z and the initialization flag are reset to 0, and the wait timer is set 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 no (N), the step shown in FIG.
Proceeding to S12, in this step S12, it is determined whether or not 1 is set in the initialization flag. In this case, the initialization flag is still reset to 0 in the initial value setting of step S1. Therefore, in this case, the determination result is NO (N). Therefore, step
The process returns from step S12 to step S2, and this step S2 is performed again. Unless the determination in step S2 becomes positive (Y), that is, unless the battery voltage VB of the DC motor 13 has reached V1 or more, step 3 is executed. No further steps are performed.

When the determination in step S2 is positive (Y),
The next step S3 is performed. In this step S3, it is determined whether or not the wait timer is 0. Here, since the wait timer is also reset to 0 in advance in the initial value setting in step S1, the determination here is positive (Y), and the next step S4 is performed. In this step S4, the initialization timer sets the predetermined time T
Is set. Here, the initialization timer is DC
It comprises a subtraction timer that operates only when the battery voltage VB of the motor 13 is equal to or higher than V1, and in this case,
In this embodiment, the predetermined time T1 is set sufficiently shorter than the time required to change the valve opening of the variable intake control valve 11 between the fully open position and the fully closed position.

In the next step S5, the DC motor 13 is driven to rotate to the closing side, whereby the valve opening of the variable intake control valve 11 is displaced toward the fully closed position. That is, when step S5 is performed, a driving step of driving the variable intake control valve 11 toward the fully closed position is performed.

While such a driving process is being performed, in the next step S6, a rotation speed sensor, in this case, a first rotation speed sensor
Whether or not the output signal from 25 is inverted, that is, the output signal from the first speed sensor 25 is changed from an ON signal to an OFF signal,
Alternatively, it is determined whether or not the signal has been inverted from the off signal to the on signal. If the determination here is positive (Y), it means that the DC motor 13 is still actually driving, and from step S6, the steps shown in FIG.
S10 is performed. In this step S10, a predetermined time T2 is set in the aforementioned wait timer. Here, the wait timer is also constituted by a subtraction timer like the initialization timer, and the predetermined time T2 is shorter than the predetermined time T1, for example, a fraction of T1.
Set to about.

From step S10, steps after step S2 are repeatedly performed.
From step S3, the determination in step S3 is
Unless the wait timer becomes 0, the value does not become positive (Y). Therefore, the process jumps to step S12, and this step S12 is performed.
Since the determination of S12 remains No (N) as described above, the process returns to step S12.

Therefore, once the determination in step S6 becomes positive (Y), that is, when the on / off signal from the first rotation speed sensor 25 is inverted during the driving process of the DC motor 13 described above. As shown in FIG. 12, the steps after step S4 are not performed until the predetermined time T2 set in the wait timer is completed, and the driving process is interrupted. .

Then, when the predetermined time T2 has elapsed, the determination in step S3 becomes positive (Y) at this point, so that step S4 is performed again. Therefore, as apparent from FIG. 12, the above-described driving step is repeatedly performed from the beginning.

Further, during the driving process of the DC motor 13, when the determination in step S6 is not positive (Y) and the determination in the next step S7 is not positive (Y), that is, when the predetermined value set in the initialization timer is set. If the time T1 has not elapsed yet, the steps after the step S5 are repeatedly executed via the step S11, or the process returns to the step S2. That is, in step S11, the DC motor 1
It is determined whether or not the battery voltage VB of No. 3 is maintained at or above V2, which is slightly lower than V1, and the determination is positive (Y).
As long as it is maintained, the process returns to step S5, and the steps from this step onward are repeatedly performed.
If the determination in S6 is not positive (Y), step S7
The DC motor 13 is driven to rotate in one direction until the determination in (1) 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
When the battery voltage VB falls below V2, step S11
Is negative (N), and the process 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.

Then, as shown in FIG. 12, step S11
Is not determined to be negative (N), and step S6
If the predetermined time T1 set in the initialization timer elapses without the determination in step (1) being positive (Y), the DC motor 13
Since the rotation drive of 13 will not be actually done,
It can be determined that the valve opening of the variable intake control valve 11 has already reached the fully closed position, and that the valve body is in a state of contact with a stopper that defines the fully closed position. Therefore, in this case, the determination in step S7 is positive (Y), and the process proceeds to the next step S8. At this point, the drive of the DC motor 13 is stopped, and in step S8, the initialization is performed. The flag is set to 1, thereby determining that the initialization of the DC motor type positioning device has been completed. still,
In FIG. 12, when the driving process of the DC motor 13 is being performed, the signal from the second rotation speed sensor 26 is inverted, but in this embodiment, the signal from the second rotation speed sensor 2 is inverted. Is ignored and only the signal from the first rotation speed sensor 25 is monitored, so that even if the signal from the second rotation speed sensor 26 is inverted, the driving process of the DC motor 13 is interrupted. Never.

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

Next, from step S9, the process proceeds to step S12 described above, and the determination in step S12, that is, whether or not the initialization flag is set to 1 is determined. When the initialization processing of the positioning device is completed as described above, since the initialization flag has already been set to 1 in step S8, in this case,
The determination is positive (Y), and in this case, the next step S13 is performed.

In step S13, the target valve opening of the variable intake control valve 11 is set, and the actual valve opening is detected. Here, the actual valve opening of the variable intake control valve 11 is determined by counting the ON / OFF signals from the first and second rotation speed sensors 25 and 26 in the actual valve opening detector 33 of the electronic control unit 30. ,
Can be calculated. That is, when the DC motor 13 is driven, the rotary shaft 20 is rotated, and as described above, the valve shaft 24 of the variable intake control valve 11 is rotated, and when the actual valve opening changes, the rotary shaft 20 is rotated. As shown in FIG. 5, a pulse signal is output from the first and second rotation speed sensors 25 and 26 in accordance with the rotation of the valve.
At 33, the actual valve opening of the variable intake control valve 11 is constantly calculated based on the fully closed position by counting the number of pulses from at least one of the rotation speed sensors, for example, the first rotation speed sensor 25. be able to. Then, in the case of this embodiment, based on the count of the on / off signal from the first rotation speed sensor 25,
The unit rotation of the DC motor 13 is defined, and as shown in FIG. 13, when the DC motor 13 is driven to rotate by 12 unit rotations, the valve opening of the variable intake control valve 11 is fully closed. It is set to change over the allowable displacement range from the position to the fully open position. Therefore, in the actual valve opening detection unit 33,
By counting the on / off signal of the first rotation speed sensor 25 and calculating the number of unit rotations of the DC motor 13, this number can be obtained as the magnitude of the actual valve opening degree θa of the variable intake control valve 11. . That is, the actual valve opening degree θa is quantified and obtained.

In the case of this embodiment, the first and second rotating shafts 20
Since two sensors of the rotation speed sensors 25 and 26 are provided, the DC motor 13 is brought into the normal rotation state 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 engine is in the reverse rotation state or not.
This is convenient when the actual valve opening degree θa is obtained from addition and subtraction of the number of pulses.

On the other hand, the target valve opening of the variable intake control valve 11 is set in a target valve opening setting section 34 of the electronic control unit 30. In the target valve opening setting section 34, a signal from the engine speed sensor 31 is used. Based on this, the target valve opening is set. That is, the target valve opening is determined from the map shown in FIG. 14 or a function defining this map. As is apparent from FIG. 14, the target valve opening of the variable intake control valve 11 is a low value when the engine speed of the internal combustion engine as a control input is a low value.
The fully closed position is set when the engine speed is in a low speed range below N1 (for example, around 3500 rpm), and is in the fully open position when the engine speed is higher than a high speed value N2 (for example, around 4500 rpm) higher than the low speed value N1. I have.

In the transition region where the engine speed is between the low speed value N1 and the high speed value N2, the valve opening is set so as to increase stepwise from the fully closed position to the fully open position as the engine speed increases. I have. That is, in the present embodiment, the actual valve opening degree detecting section 33 detects between the low speed value N1 and the high speed value N2 according to the actual valve opening degree θa of the variable intake control valve 11 detected as described above. That is, the variable allowable range of the valve opening is
As shown in the figure, the control sections are divided into twelve control sections at equal intervals, and each control section is gradually increased from the low speed value N1 side to the high speed value N2 side. Each target valve opening degree θ ₀ is set. Therefore, the engine speed
If there between N1 and N2 can be set to a number of control segments that engine speed belongs, as the target valve opening theta _0.

Immediately after the initialization processing of the DC motor type positioning device is performed, the actual valve opening θ of the variable intake control valve 11 is changed.
a is the fully closed position, that is, 0, as described above. Further, when the variable intake control valve 11 is positioned at the fully closed position in the initialization process, the variable intake control valve is opened at the time of starting the internal combustion engine, as is apparent from FIG. This means that the internal combustion engine is already positioned at the degree θ _0, and the startability of the internal combustion engine is improved.

Then, in the Miben opening detector 33 and the target valve opening setting unit 34, when Miben opening θa and the target valve opening theta ₀ of the variable intake control valve 11 is calculated respectively, which are electronic control Device 30
Is supplied to the control unit 35 for processing. That is, according to the flowchart of FIG.
4 is executed. In this step S14, the target valve opening θ ₀
Is larger than the actual valve opening θa. If the determination here is positive (Y), in the next step S15, the target valve opening θ ₀ is set to the fully open position, that is, the numerical value is set to 12
Is determined. If the determination is no (N), the process proceeds to step S20 shown in FIG.
The C motor 13 is driven to the open side.

That is, in this case, since the determination in the previous step S14 is positive (Y), the DC motor 13 is driven in a direction to open the variable intake control valve 11, and in the next step S21,
After the X flag is reset to 0, the process returns to step S12, and the subsequent steps, that is, the steps after the above-described initialization processing in the positioning device are repeatedly performed.

Here, during the repetition of the above-described steps, step S1
If the determination in step 4 is negative, step S22 in FIG.
Advances to, and, at step S22, contrary to the case in step S14, the target valve opening theta ₀ is determined whether or not less than Miben opening .theta.a and also determination of where If not (N), in the next step S23, the X, Y, and Z flags are reset to 0, and the process returns to step S12. Therefore, in such a case, since Miben opening θa of variable intake control valve 11 coincides with the target valve opening theta _0, the step S12 through the steps S13, S14, S22 and S23, Only the routine that returns to step S12 is repeated, and the DC motor 13 is not driven.

Then, the process proceeds from step S14 to step S15, and if the determination in step S15 is positive (Y),
That is, if the target valve opening degree θ ₀ of the variable intake control valve 11 is the fully opened position, that is, if its numerical value is 12, the next step
S16 is performed, and in this step S16, the variable intake control valve
It is determined whether or not the 11 actual valve opening θa is the valve opening just before the fully open position, that is, if the valve opening is indicated by a numerical value, it is 11 or not. If the determination here is negative, the steps subsequent to step S20 are performed, so that the opening-side drive routine for increasing the valve opening of the variable intake control valve 11 is repeated as described above. Will be.

When the drive routine to the open side is repeated in this manner, if the determination in step S16 becomes positive (Y), that is, in this case, the actual valve opening degree θa of the variable intake control valve 11 is When the value reaches 11 in numerical terms, step S17 is performed in this case. In this step S17, it is determined whether or not the Y flag is set to 1. In this case, since the Y flag is still being reset to 0, the determination here is not (N). And the next step S18 is performed. In this step S18, a predetermined time T2 is set in the aforementioned wait timer, and 1 is set in the Y flag.

Thereafter, the above-described step S19 is performed, but here, since the predetermined time T2 is set in the wait timer in the previous step S18, the determination here is negative (N). Therefore, in this case, the step S20 is bypassed, the X flag is reset to 0 in the step S21, the process returns to the step S12, and the steps after the step S12 are repeatedly executed. . However, in this case, in the next routine, step S17
Is positive, step S18 is bypassed. Therefore, such a repeated routine is continued until the determination in step S19 becomes positive, that is, until the predetermined time T2 set in the wait timer is completed.

Then, when the predetermined time T2 is completed, the determination in step S19 becomes positive (Y) at this time, so
S20 is performed, and the DC motor 13 is driven to the closed side. Accordingly, the variable intake control valve 11 is configured such that the actual valve opening θa changes from 11 to 12 from the position immediately before the fully open position to the fully open position, that is, when the actual valve opening θa is viewed as a numerical value. Driven.

Thereafter, when the actual valve opening degree θa of the variable intake control valve 11 reaches the fully opened position, the determinations in steps S14 and S22 are respectively negative as described above, and the process returns to step S12 via step S23, and Steps after step S12 are repeated.

Here, to summarize the above description, the variable intake control valve
11 when the target valve opening θ ₀ is larger than the actual valve opening θa, and the target valve opening θ ₀ is in the fully closed position, that is,
If the numerical value is set to 12, as shown in FIG. 16, during the driving of the DC motor 13 to the open side, the variable intake control valve
When the actual valve opening θa of 11 reaches the valve opening position immediately before the fully open position, that is, reaches 11 in numerical terms, the DC motor 13 is driven again after its driving is stopped for a predetermined time T2, Accordingly, Miben opening θa of variable intake control valve 11 will be positioned to the target valve opening theta ₀ is a fully open position.

In this case, when the target valve opening theta ₀ of the variable intake control valve 11 is set to the valve opening other than fully open position, at its middle, without performing the drive stop of the DC motor 13 ,
Its Miben opening θa will be positioned in the target valve opening theta _0.

The above description is based on the target valve opening θ of the variable intake control valve 11.
₀ but is larger than Miben opening .theta.a, however, in the step of step S12 and subsequent steps are performed repeatedly, so that the target valve opening theta ₀ is smaller than Miben opening .theta.a In such a case, the determination in step S14 is negative (N), and the subsequent step S22
Is positive (Y), the steps after step S24 are performed for the first time.

In step S24, first, it is determined whether or not the X flag is set to 1. Here, immediately after the above-described initialization processing of the positioning device is performed, the processing proceeds through steps S12, S13, S14, and S22. Therefore, even when the process proceeds to step S24, or when the process proceeds to step S24 after the steps after step S15 have already been performed, the X flag is always reset to 0. N), and the next step S25 is performed. In the step S25, Miben opening θa than the target valve opening theta _0, whether two or more larger as viewed in the numerical value is determined. If this determination is NO (N), step S25
In this case, the DC motor 13 is not driven in this case, since only the routine that immediately returns to step S12 is repeated.

However, the if the judgment is positive (Y) in step S25, at the next step S26, the target valve opening theta ₀ of the variable intake control valve 11 is fully closed position, i.e., when viewed in numerical 0
Is determined. If the determination here is negative (N), steps S27 to S30 are bypassed and step S31
In this step S31, the DC motor 13 is driven to the closed side. That is, in this case, since the determination in the previous step S22 is positive (Y), the DC motor 13 is driven in a direction to close the variable intake control valve 11, and the next step S3
In step 2, after the X flag is set to 1,
Returning to 12, the subsequent routines will be repeatedly executed.

Here, when the above routine is repeated, when step S24 is reached again, in this case, since the X flag has already been set to 1, the determination here is positive (Y), and therefore, In other words, the routine bypasses step S25 to reach step S26.

If the determinations in steps S14 and S22 are both negative while the above-described routine is being repeatedly executed, the process returns to step S12 via step S23. That is, in this case, since Miben opening θa of variable intake control valve 11 is means that matches its target valve opening theta _0, is at Thereafter, step from step S12 S13, S14 , S22 and S23, the routine of returning to step S12 is simply repeated,
Is not driven. Here, when the routine to match the Miben opening θa of variable intake control valve 11 to the target valve opening theta ₀ in this way is repeated, as is clear from the foregoing description, step S25 is bypassed Will be done. That is, when the step S25 is performed once and the determination is positive (Y), the step S3 is always performed.
Since 1 2 is carried out in the X flag is set, at Thereafter, Miben opening θa of variable intake control valve 11 is equal to the target valve opening theta _0, as long as the step S23 is not carried out Since the determination in step S24 is positive (Y), step S25 is not performed.

Further, the process proceeds to step S26 via the above-described step S25, and when the determination in step S26 is positive (Y),
That is, when the target valve opening of the variable intake control valve 11 is set to the fully closed position, that is, 0 when viewed numerically, the next step
S27 is performed, and in this step S27, the variable intake control valve
It is determined whether or not the eleventh actual valve opening θa is the valve opening just before the fully closed position, that is, whether or not the valve opening is 1 when the valve opening is indicated by a numerical value. If the determination here is negative, the steps subsequent to step S31 are performed, so that the closing-side drive routine for reducing the valve opening of the variable intake control valve 11 is repeated as described above. Will be. Here, once the X flag is set to 1 after passing through step S32, step S25 is bypassed.

When the drive routine to the open side is repeated in this manner, if the determination in step S27 becomes positive (Y), that is, in this case, the actual valve opening degree θa of the variable intake control valve 11 is If the numerical value reaches 1, in this case, the next step S28 is performed. In this step S28, Z
It is determined whether the flag is set to 1 or not.
In this case, since the Z flag is still being reset to 0, the determination here is negative (N), and the next step S29 is performed. In this step S29, a predetermined time T2 is set in the wait timer in the same manner as described above, and 1 is set in the Z flag.

Thereafter, in the next step S30, it is determined whether or not the predetermined time T2 set in the wait timer has been completed.Here, in the previous step S29, the predetermined time T2 is set in the wait timer. Since it is immediately after the setting, the determination here is negative (N). Therefore, in this case, the drive of the DC motor 13 is stopped by bypassing step S31, and the process goes through step S32. Later, step S12
Then, the routine from step S12 is repeatedly executed. In this case, the following routine:
Since the determination in step S28 is positive (Y), step S28
29 will be bypassed. Accordingly, the state in which the driving of the DC motor 13 is stopped by bypassing step S31 in this repetitive routine,
The process is continued until the determination in S30 becomes positive, that is, until the predetermined time T2 set in the wait timer is completed.

Then, when the predetermined time T2 is completed, the determination in step S30 becomes positive (Y) at this point, so that step S30 is performed again.
Step S31 is performed, and the DC motor 13 is driven to the closed side. As a result, the variable intake control valve 11 changes its actual valve opening degree θa from the position immediately before the fully closed position to the fully closed position, that is, when the actual valve opening degree θa reaches a numerical value from 1 to 0. Driven as follows.

Thereafter, when the actual valve opening degree θa of the variable intake control valve 11 reaches the fully closed position, the determinations in steps S14 and S22 are respectively negative as described above, and the process returns to step S12 via step S23. Steps after step S12 are repeated.

Here, the operation on the closing side of the variable intake control valve 11 described above can be summarized as follows.
_{If 0} is smaller than the actual valve opening θa, and if the target valve opening θ ₀ is set to the fully closed position, that is, 0 in numerical terms, as shown in FIG. , DC motor
While the valve 13 is being driven to the closed side, the actual valve opening θa of the variable intake control valve 11 is
Is the valve opening position immediately before the fully closed position, that is, 1
When reached, DC motor 13, the driving is stopped for a predetermined time T2, and, thereafter, is driven again, Miben opening θa of variable intake control valve 11, the target valve opening theta ₀ At the fully closed position.

In this case, if the target valve opening θ ₀ of the variable intake control valve 11 is set to a valve opening other than the fully closed position, the drive of the DC motor 13 should be stopped halfway. Not
Its Miben opening θa will be positioned in the target valve opening theta _0.

Further, in this embodiment, when the variable intake control valve 11 begins to be driven in the full closing direction, if there is no more viewed in numerical difference between the Miben opening θa and the target valve opening theta _0, the step
Since the determination in S25 is negative (N), in such a case, D
The C motor 13 is not driven to rotate. Therefore, if the Miben opening θa of variable intake control valve 11 is varied toward the target valve opening theta ₀ fully closed position side, for example, assuming that Miben opening θa is in the fully open position, the Target valve opening θ
_In FIG. 16, only the target valve opening θ ₀ except for the valve opening position immediately before the fully closed position can be substantially set as indicated by the one-dot chain line in FIG.

On the other hand, the variable intake control valve 11 toward its target valve opening theta ₀ side once and at after driven by the DC motor 13, by step S32 is carried out, carried out in step S25 after this Since the stop is stopped, the drive of the DC motor 13 is not stopped at the valve opening position immediately before the target valve opening θ ₀ unless the target valve opening θ ₀ is numerically ₀ .

As is clear from the above description, the actual valve opening θa of the variable intake control valve 11 is changed according to the engine speed in accordance with the target valve opening characteristic shown in FIG. The actual valve opening degree θa of the valve 11 is maintained at the fully closed position when the engine speed is equal to or lower than N1, so that the intake air supplied to the combustion chamber 1 of the internal combustion engine passes through the bypass intake passage 12 for a long time. If the engine speed is higher than N2, the variable intake control valve
Since the 11 actual valve opening degree θa 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 path including only the main intake passage 2. When the engine speed is between N1 and N2, the variable intake control valve 11
Of the actual valve opening θa is changed stepwise between the fully closed position and the fully opened position in accordance with an increase in the engine speed.

Accordingly, the output torque of the internal combustion engine is as shown in FIG. 17, and as apparent from FIG. 17, a high output torque can be obtained over the entire range of the engine speed. Fluctuations in output torque when the control valve 11 shifts from fully closed to fully open can also be suppressed to a small value.

In the above-described embodiment, when the target valve opening degree θ ₀ of the variable intake control valve 11 is set to the fully closed position or the fully opened position,
Furthermore, in the initialization process of the positioning device,
When the variable intake control valve 11 is located at the fully closed position, which is the initial position, when the actual valve opening θa is located at the fully opened position or the valve opening position immediately before the fully closed position, In the case of the processing, the drive of the DC motor 13 is stopped for a predetermined time T2 every time the signal from the first rotation speed sensor 25 is inverted, and then the DC motor 13
Is driven again to set the actual valve opening θa to the fully open position or the fully closed position, so that the valve body of the variable intake control valve 11 can be gently positioned at the fully open position or the fully closed position.

That is, in this regard, since the motor speed of the DC motor 13 has a characteristic as shown in FIG. 18 with respect to the energization time, the motor speed is at the start of the energization, that is, It is slow at the start of driving, and therefore, when the valve body of the variable intake control valve 11 reaches the fully open position and the fully closed position from the immediately preceding valve opening position, the fully open position or the fully closed position is largely overrun. Is not driven. Therefore, not only can the valve body of the variable intake control valve substantially collide with the stopper that defines the fully open position and the fully closed position, but also the valve body can Strong collision can be reliably prevented. As a result, not only can the valve body of the variable intake control valve be prevented from being damaged, but also the DC motor 13 can be prevented from being damaged, and the durability of the positioning device can be improved.

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, in one embodiment, only when the variable intake control valve is driven toward its fully closed position, if the difference between the target valve opening and the actual valve opening is not greater than or equal to a predetermined value, the DC motor Although the drive is not performed, the hysteresis for the drive of the DC motor may be provided even when the variable intake control valve is driven toward its fully open position.

Further, the present invention is not only applicable to a DC motor type positioning device incorporated in a variable intake system, for example, because the DC motor type positioning device controls the opening degree of an idle speed control valve of an internal combustion engine. It goes without saying that the method of the present invention can be carried out even when used in

(Effect of the Invention) As described above, according to the drive control method of the DC motor type positioning device of the present invention, when the target position of the object is the end position defined by the stopper, the object is positioned at the end position. At least at the time when the DC motor reaches the immediately preceding position, the driving of the DC motor is stopped for a predetermined time, and thereafter, the DC motor is driven again, whereby the object is positioned at the end position which is the target position. Therefore, when the object is positioned at the end position, the DC motor has a relatively low motor speed immediately after its driving has been resumed, so that the object can be positioned at the end position gently. Can be. As a result, an excellent effect is obtained in that the object does not collide with the stopper at the end position with a large force and is not damaged, and the collision does not cause damage to the DC motor itself.

[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 to 11 are flowcharts for explaining the control operation of the variable intake system, and FIG. 12 schematically shows the operation of the DC motor and the rotation speed sensor when the initialization processing of the positioning device is performed. Time chart shown, thirteenth
FIG. 14 is a graph showing the relationship between the actual valve opening of the variable intake control valve and the number of unit rotations of the DC motor, FIG. 14 is a graph showing target valve opening characteristics of the variable intake control valve, and FIG. FIG. 14 is a graph showing a part of the details of the graph of FIG. 14, showing the relationship between the engine speed and the target valve opening, and FIG. 16 is a DC motor schematically showing the valve opening control of the variable intake control valve. FIG. 17 is a time chart showing the relationship between the operation and the valve opening, FIG. 17 is a graph showing the relationship between the output torque of the internal combustion engine obtained by the operation of the variable intake system and the engine speed, and FIG. 4 is a graph showing the relationship between the current supply time and the motor speed. 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 the front page (56) References JP-A-2-74197 (JP, A) JP-A-62-22210 (JP, A) JP-A-54-53459 (JP, A) JP-A-59-1979 113224 (JP, A) JP-A-60-11638 (JP, A) JP-A-61-223236 (JP, A)

Claims (1)

(57) [Claims] 1. A DC motor connected to an object to be position-controlled via a power transmission path and having a characteristic that a rotation speed increases toward a maximum speed with the passage of time from the start of energization, and the DC motor A rotation speed sensor that detects the rotation speed of the rotation shaft included in the power transmission path, a stopper that defines the end position of the allowable displacement range of the object, and the actual position of the object based on the signal from the rotation speed sensor On the other hand, the actual position is compared with a target position set according to a change in the control input, and in a DC motor type positioning device that drives a DC motor so that the actual position coincides with the target position, When the target position is set at the end position, when the actual position of the object reaches at least the position immediately before the end position,
A drive control method for a DC motor-type positioning device, wherein the DC motor is stopped for a predetermined time, and then the DC motor is driven again to position the actual position of the object at an end position which is a target position.