JP2012047126A - Automatic start-stop control device for engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an automatic start-stop control device for an engine that is connected to an automatic transmission and causes the engine to automatically start and stop on the basis of a predetermined stop condition.SOLUTION: The automatic start-stop control device for the engine has a control configuration such that upon detection of increase equal to or above a predetermined value of engine rotation speed and/or turbine rotation speed by release of throttle opening control after an automatic start, the throttle opening control is restarted, extension of a time required until clutch engagement from an increase amount of the engine rotation speed and/or turbine rotation speed is estimated, and a throttle opening is gradually increased by the throttle opening control.

Description

The present invention relates to an automatic start control device for a vehicle engine having a belt type continuously variable transmission and having an idle stop function.

In recent years, from the viewpoint of energy saving and environmental problems, improvement of fuel efficiency and improvement of energy efficiency in vehicles are desired. From such a viewpoint, a vehicle equipped with a continuously variable transmission (CVT) as disclosed in Patent Document 1 below is provided. Further, in order to further improve fuel efficiency, as disclosed in Patent Document 2 below, the engine operation is automatically stopped on condition that a predetermined condition is satisfied when driving is stopped in a signal or the like, There has been provided a vehicle having an idle stop function for automatically restarting an engine when starting.

As will be described in detail later with reference to FIG. 1, as a technique for returning the engine from the idle stop state to the normal driving state, the opening of the throttle valve is adjusted so that the engine speed does not exceed a predetermined value. There is an automatic start / stop control device for an engine that controls the increase in engine speed. For example, Patent Documents 3 and 4 listed below disclose techniques for controlling an increase in engine speed by controlling the opening of a throttle valve.

JP 2001-47892 A JP 2003-175747 A JP 2010-71205 A JP 2010-13994 A

In the engine automatic start / stop control device described in FIG. 1 or Patent Documents 3 and 4 described above, when the engine speed is greatly increased, the vehicle body acceleration time lasts long, and the time for which the engine speed should be controlled by throttle control. Becomes longer than the standard time. This time difference is a cause of shock when the clutch is engaged.

The present invention has been created in view of the above-described problems, and the present invention suppresses the engine speed even when the engine speed is greatly increased after the engine has been automatically started from the idle stop, and at the time of clutch engagement. An object of the present invention is to provide an automatic start / stop control device for an engine that can alleviate a shock.

Specifically, the present invention provides an automatic start / stop control device for an engine that is connected to an automatic transmission and that automatically starts and stops the engine based on a predetermined stop condition. The automatic start control device detects that the engine speed and / or the turbine speed has increased to a predetermined value or more by releasing the throttle opening control after the automatic start (see, for example, T1 in the embodiment of FIG. 3). Then, the throttle opening degree control is restarted (for example, refer to the time T2 in the embodiment of FIG. 3), and it is estimated that the time required until the clutch is engaged from the increase amount of the engine speed and / or the turbine speed. Then, the throttle opening is gradually increased by the throttle opening control (for example, see the time from T3 to T6 in the embodiment of FIG. 3).

In the present invention, when the engine speed and / or the turbine speed is detected to be equal to or higher than a predetermined value after the engine is automatically started after the end of the idle stop, the time until clutch engagement is predicted, and the throttle opening according to this time is estimated. The throttle opening is gradually increased by the degree control. As a result, even when the engine speed greatly increases after the automatic start, the shock at the time of clutch engagement can be reduced.

Further, the automatic start / stop control device of the engine is configured to predict the convergence time of the turbine speed from the increase from the predetermined value of the turbine speed after the automatic start, and to stop the control of the throttle opening. May be.

In this engine automatic start / stop control apparatus, the amount of time shift until clutch engagement is predicted from the increase in turbine speed. Thus, as described above, even when the engine speed greatly increases after the automatic start, the shock can be reduced when the clutch is engaged.

As described above, according to the engine automatic start / stop control device of the present invention, even when the engine speed is greatly increased after the engine is automatically started from the idle stop, the throttle opening degree depends on the estimated time until the clutch is engaged. Since the control is performed, the shock at the time of clutch engagement can be reduced. In addition, it is possible to suppress deterioration in fuel consumption due to blowing up of the engine speed.

1 is a skeleton diagram showing a transmission system employed in a vehicle equipped with a start control device according to an embodiment of the present invention. 6 is a timing chart showing the operating state of each part when the engine speed after starting idling stop return is less than or equal to a predetermined value or more in a conventional automatic start / stop control device. It is the timing chart which showed the operation condition of each part before and behind correction of electronic throttle guard control with the automatic start / stop control device of the present invention. It is a flowchart which shows the correction process of electronic throttle guard control with the automatic start stop control apparatus of this invention.

Next, a vehicle A equipped with a start control device C according to an embodiment of the present invention will be described in detail with reference to the drawings. The vehicle A of the present embodiment is characterized by its control configuration, but an outline of a transmission system employed in the vehicle A will be described prior to the description of the control configuration portion.

The vehicle A of this embodiment includes a transmission system T, an engine E, and a start control device C as shown in FIG. The transmission system T is an FF horizontal transmission for an automobile, and is transmitted to the drive shaft 10 by switching the rotation of the input shaft 3 and the input shaft 3 driven by the engine output shaft 1 via the torque converter 2 between forward and reverse. The forward / reverse switching device 4, the continuously variable transmission 7 including the drive pulley 11, the driven pulley 21, and the V belt 15 wound between both pulleys, and the differential device 30 that transmits the power of the driven shaft 20 to the output shaft 32. Etc. The input shaft 3 and the drive shaft 10 are arranged on the same axis, and the driven shaft 20 and the output shaft 32 of the differential device 30 are arranged parallel to the input shaft 3 and non-coaxially. Therefore, the transmission system T has a three-axis configuration as a whole.

The V-belt 15 employed in this embodiment is a known metal belt composed of a pair of endless tension bands and a large number of blocks supported by these tension bands.

Each component constituting the transmission system T is accommodated in the transmission case 5. An oil pump 6 is disposed between the torque converter 2 and the forward / reverse switching device 4. Although not shown in FIG. 1, the oil pump 6 includes an oil pump body fixed to the transmission case 5, an oil pump cover fixed to the oil pump body, and between the oil pump body and the oil pump cover. And a pump gear housed in the housing. The pump gear is driven by the pump impeller 2 a of the torque converter 2. The turbine runner 2b of the torque converter 2 is connected to the input shaft 3, and the stator 2c is supported by the transmission case 5 via the one-way clutch 2d.

The oil pump 6 is operated by power input from the engine E. Accordingly, the operation of the oil pump 6 is interlocked with the engine E. That is, while the engine E is operating, the oil pump 6 is also operated, but when the engine E is stopped, the oil pump 6 is also stopped. Also, by operating the oil pump 6, oil can be pumped toward the hydraulic operation devices such as the forward / reverse switching device 4 and the CVT 7 to be described in detail later, and the line pressure (hydraulic pressure) can be applied. Therefore, the hydraulic pressure cannot be applied to the forward / reverse switching device 4 or the CVT 7 while the engine E is stopped.

The forward / reverse switching device 4 includes a planetary gear mechanism 40, a reverse brake 50, and a direct coupling clutch 51. The planetary gear mechanism 40 is of a so-called single pinion type, in which a sun gear 41 is connected to the input shaft 3 that is an input rotating member, and a ring gear 42 is connected to the drive shaft 10 that is an output rotating member. . The reverse brake 50 corresponds to the starting clutch in the present invention, and is provided between the carrier 44 that supports the pinion gear 43 and the transmission case 5. The direct coupling clutch 51 is provided between the carrier 44 and the sun gear 41. When the direct clutch 51 is released and the reverse brake 50 is engaged, the rotation of the input shaft 3 is reversed and decelerated and transmitted to the drive shaft 10. Conversely, when the reverse brake 50 is released and the direct clutch 51 is engaged, the carrier 44 and the sun gear 41 of the planetary gear mechanism 40 rotate together, so that the input shaft 3 and the drive shaft 10 are directly connected.

The drive pulley 11 of the continuously variable transmission 7 includes a fixed sheave 11a, a movable sheave 11b, and a hydraulic servo 12. The fixed sheave 11 a is integrally formed on the shaft of the drive shaft (pulley shaft) 10. The movable sheave 11b is supported on the drive shaft 10 via a roller spline portion so as to be axially movable and integrally rotatable. The hydraulic servo 12 is provided behind the movable sheave 11b. A piston portion extending to the back side is integrally formed on the outer peripheral portion of the movable sheave 11b (not shown), and the outer peripheral portion of this piston portion is an inner peripheral portion of a cylinder (not shown) fixed to the drive shaft 10. Is in sliding contact. A hydraulic oil chamber 12a of the hydraulic servo 12 is formed between the movable sheave 11b and the cylinder, and the shift control is performed by controlling the hydraulic pressure to the hydraulic oil chamber 12a.

The driven pulley 21 includes a fixed sheave 21a, a movable sheave 21b, and a hydraulic servo 22. The fixed sheave 21 a is integrally formed on the driven shaft (pulley shaft) 20. The movable sheave 21b is supported on the driven shaft 20 via a roller spline portion (not shown) so as to be axially movable and integrally rotatable. The hydraulic servo 22 is provided behind the movable sheave 21b. A cylinder portion (not shown) extending to the back side is integrally formed on the outer peripheral portion of the movable sheave 21b, and a piston (not shown) fixed to the driven shaft 20 is in sliding contact with the inner peripheral portion of the cylinder portion. Yes. A hydraulic oil chamber 22a of the hydraulic servo 22 is formed between the movable sheave 21b and the piston. By controlling the hydraulic pressure of the hydraulic oil chamber 22a, a belt thrust necessary for torque transmission is given. Note that a spring 24 for applying an initial thrust is disposed in the hydraulic oil chamber 22a.

One end of the driven shaft 20 extends toward the engine E side, and the output gear 27 is fixed to this one end. The output gear 27 meshes with the ring gear 31 of the differential device 30, and power is transmitted from the differential device 30 to the output shaft 32 extending left and right to drive the wheels.

The engine E is constituted by an internal combustion engine and includes an electronically controlled throttle S that can adjust the opening degree (output). The engine E is connected to the transmission system T described above via the output shaft 1, and power can be input to the torque converter 2 and the oil pump 6. The engine E is operation-controlled so as to operate in cooperation with the CVT 7 described above.

The vehicle A automatically stops the operation of the engine E by a control signal from the start control device C on condition that the predetermined operating condition is satisfied when the traveling is stopped, and the engine E is automatically started when the vehicle starts. An automatic start / stop control device having a function of restarting the engine (idle stop function) is provided. In this embodiment, the opening degree of an accelerator (not shown) is not more than a predetermined opening degree, the vehicle speed is 0 [Km / h], and the water temperature of the engine E is within a predetermined temperature range. The battery power supply voltage is equal to or higher than a predetermined voltage, the battery power supply temperature is within a predetermined temperature range, the battery power supply is sufficiently charged, the brake pedal is on, etc. Is set as the operating condition of the idle stop function. Further, when the accelerator opening degree becomes larger than a predetermined opening degree and the above-mentioned operating condition is not satisfied, the idle stop function is canceled, the engine E is automatically started, and the vehicle A can travel. Return to the state.

In the vehicle A of the present embodiment, the throttle S opening degree is set in a state where certain conditions are satisfied from the viewpoint of blowing up the engine E immediately after the start of automatic start, preventing shock at the start, and eliminating the feeling of rattling. Control for adjustment (hereinafter also referred to as “electronic throttle guard control”) is performed by the start control device C.
The operation from the start of the automatic start to the end of the electronic throttle guard control will be described below.

≪Conventional problems≫
First, the operation state of each part in a conventional engine automatic start / stop control apparatus will be described with reference to a timing chart shown in FIG. The upper part (a) of FIG. 2 shows the engine speed and turbine speeds re1 and rt1 when the engine rotates to a normal degree, and re2 and rt2 in the case of the engine speed and turbine speed when the engine blows up. The middle stage (b) shows the opening / closing degree s of the electronic throttle S based on the so-called electronic throttle guard control, and the lower stage (c) shows the case where the vehicle body acceleration a1 when the engine rotates normally and the engine blows up. Vehicle body acceleration a2.

When the vehicle A is automatically stopped by the idle stop function, the rotation of the engine E is stopped and the throttle S is also closed. Along with this, the oil pump 6 is also stopped, and a state in which no clamping pressure is applied to the V belt 15 (a state in which no line pressure is applied) is entered. Thereafter, when the conditions for restarting the vehicle A such as the accelerator opening being greater than the predetermined opening are met, cranking is started to restart the engine E (at time t0 to t1). In addition, when cranking is performed and engine self-sustaining rotation is started (at time t1), electronic throttle guard control is subsequently started (after time t1).

At the time of cranking (at time t0), the electronic throttle S is closed. When the engine E reaches a rotational speed at which the engine E can rotate independently during a predetermined time (t0 to t1) during cranking, the rotational speed of the engine E thereafter, the clamping pressure acting on the V belt 15 in the CVT 7, The opening degree of the electronic throttle S is adjusted according to the engagement state of the clutch.

More specifically, after t1, the rotational speed of the engine E reaches a predetermined rotational speed or higher (that is, a return condition rotational speed for independent rotation), and the clamping pressure acting on the V belt 15 exceeds a predetermined value. When it is confirmed that the clutch has started to be engaged, electronic throttle guard control is performed so that the opening of the throttle S gradually increases at a predetermined increase rate in time series (from t1 to t2: In the accompanying drawings, the electronic throttle guard is also abbreviated as “electric throttle guard”). At this time, as the engagement state of the clutch 50 advances, the engine speed re1 gradually increases, but the turbine speed rt1 decreases. Then, when a predetermined time has elapsed, the electronic throttle guard control is terminated, the electronic throttle S returns to the opening degree corresponding to the accelerator opening degree, and the vehicle body acceleration a1 corresponding to the accelerator opening degree is reached (after t2).

However, when the engine speed greatly increases after t1 as shown by re2 in FIG. 2A, the electronic throttle guard control ends before the turbine speed rt2 converges (from t2 to t3). That is, it takes time to engage the clutch from the usual time t2 to t3. Therefore, there is a problem that the vehicle body acceleration a2 becomes excessive from t2 to t3 and the shock at the time of clutch engagement becomes large.

<< Embodiment of the Invention >>
FIG. 3 shows a timing chart of the operation state of each part before and after correction of electronic throttle guard control in the automatic start / stop control device of the present invention. The upper part (a) of FIG. 3 shows the engine speeds RE1 and RE2 and the turbine speeds RT1 and RT2 before and after the correction of the electronic throttle guard control, and the middle part (b) shows the electronic throttle before and after the correction of the electronic throttle guard control. Opening / closing degrees S1 and S2 are shown, and the lower part (c) shows vehicle body accelerations A1 and A2 before and after the correction of the electronic throttle guard control. After that, when the engine speed is greatly increased, each time chart when the electronic throttle guard control before correction (that is, normal) is performed is shown as engine speed RE1, turbine speed RT1, electronic throttle guard control S1, vehicle body The acceleration is indicated by A1. This is as mentioned in FIG. 2, and the shock at the time of clutch engagement is great at T6.

As in FIG. 2, cranking is started when the engine E restart conditions are met after the engine E is stopped by the idle stop function (at time T0 to T1). Thereafter, the engine starts to rotate independently (at time T1), and electronic throttle guard control is started (after time T1). In the case of a large increase in the engine speed, the example of the engine automatic start / stop control device according to the present invention delays the electronic throttle guard control until after the turbine speed has converged. This is indicated by the engine speed RE2, turbine speed RT2, electronic throttle guard control S2, and vehicle body acceleration A2 in the time chart of FIG. Specifically, when the engine starts to rotate independently, the electronic throttle guard control is started to gradually increase the opening of the throttle S (from T1 to T2), but it is detected that the engine speed is greatly increased. Then, the electronic throttle guard control is restricted and the throttle S is closed (at time T2). At this time, the time during which the electronic throttle guard control is limited (from T2 to T3) is determined from the increase amount of the engine speed and the turbine speed. This determination is based on the estimation of the delay of the clutch engagement time due to the large increase in the engine speed, and particularly based on the estimation of the delay in the convergence time of the turbine speed.

When the electronic throttle guard control is restricted and a predetermined time (= T3-T2 = T6-T5) elapses, the electronic throttle guard control is started (returned) again, and the same electronic throttle guard control as in the normal case is performed. By this electronic throttle guard control correction S2, the throttle S is released from T5 when the turbine speed has not converged to T6 after completion of the convergence of the turbine speed, and the vehicle body acceleration is reduced from A1 to A2. Thus, the shock when the clutch is engaged can be reduced.

In other words, in the engine automatic start / stop control device of the present invention, when it is detected that the engine speed has greatly increased, the electronic throttle guard control is shifted and started for a predetermined time, and the control correction is performed. The throttle guard control configuration itself is a control configuration that relies only on the time from restriction to return of electronic throttle guard control without modification. Such a simple control configuration is advantageous in that a shock reduction at the time of clutch engagement can be achieved.

Subsequently, a control process in the engine automatic start / stop control apparatus example of the present invention shown in FIG. 3 will be described according to a flowchart shown in FIG. In step 10, it is determined whether the cranking is completed and the engine self-sustaining rotation is started. If it is determined that the self-sustaining rotation has started, it is determined whether sufficient clamping pressure (line pressure) is secured to the V belt 15 (STEP 12). On the other hand, if it is determined that the engine is not rotating independently, the electronic throttle guard control is limited, and the throttle remains closed (STEP 24).

Next, when it is determined that the pinching pressure on the V-belt 15 is sufficiently secured (STEP 12), it is determined whether or not the clutch engagement is started (STEP 14). On the other hand, if it is determined that the clamping pressure on the V-belt 15 is not sufficiently secured, the electronic throttle guard control is limited and the throttle remains closed (STEP 24).

Next, when it is determined that the clutch engagement is started (STEP 14), the electronic throttle guard control is started (returned) (STEP 16), and the increase in the engine speed is determined (STEP 18). On the other hand, if it is determined that the clutch engagement is not started, the electronic throttle guard control is limited and the throttle remains closed (STEP 24).

Next, when it is determined that the engine speed does not increase, that is, when it is determined that the engine speed does not increase by a predetermined value or more (STEP 18), the electronic throttle guard control is already started (returned). Continue (STEP 22). On the other hand, if it is determined that the engine speed has been increased (STEP 18), the electronic throttle guard control is limited and the throttle is closed until a predetermined time (see times T2 to T3 in FIG. 3) elapses (see FIG. 3). (STEP20, STEP24). When a predetermined time (see times T2 to T3 in FIG. 3) has elapsed, the electronic throttle guard control is started (returned) again, and the throttle opening is gradually increased according to the control. (STEP20, STEP22).

As described above, according to the example of the engine automatic start / stop control device of the present invention, even when the engine speed is greatly increased after the engine is automatically started from the idle stop, the throttle opening degree according to the predicted time until the clutch is engaged. Since the control is performed, the shock at the time of clutch engagement can be reduced. In the above-described embodiments of FIGS. 3 and 4, whether or not the engine speed has greatly increased is detected and determined based on the increase amount of the engine speed, and further, the increase amount of the turbine speed is used as a detection determination factor. Also good. Further, in the embodiment of FIGS. 3 and 4 and the above description, a method of regulating and returning the electronic throttle guard control by estimating the delay of the clutch engagement time from the increase amount of the engine speed and the turbine speed at the start of self-sustaining rotation However, a method of controlling the throttle opening by directly detecting and determining the clutch engagement state from the convergence state of the turbine rotational speed is also conceivable.

7 Belt type continuously variable transmission (CVT)
E Engine C Start controller S Throttle

Claims (2)

An automatic start / stop control device for an engine connected to an automatic transmission and automatically starting and stopping the engine based on a predetermined stop condition,
Detecting that the engine speed and / or turbine speed has increased to a predetermined value or more by releasing the throttle opening control after the automatic start, restarting the throttle opening control and restarting the engine speed and / or turbine speed An automatic start / stop control device for an engine characterized in that an increase in time required for clutch engagement is estimated from an increase amount of the engine and the throttle opening is gradually increased by throttle opening control. 2. The automatic engine start according to claim 1, wherein a convergence time of the turbine rotational speed is predicted from an increase amount of the turbine rotational speed after the automatic startup from a predetermined value, and control of the throttle opening is stopped. Stop control device.

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