JP4872664B2 - Engine control device - Google Patents

Description

  The present invention relates to an engine control device, and more particularly, to an engine control device that synchronizes the rotational speed of an engine with the output rotational speed of a clutch when a clutch is disengaged to change speed.

  When the clutch is released at the time of shifting, the input rotational speed of the clutch changes according to the rotational speed of the engine, and the output rotational speed of the clutch changes according to the vehicle speed and the transmission gear ratio. For this reason, if the clutch is engaged as it is after changing the gear ratio of the transmission, a shift shock occurs due to the rotational speed difference.

In order to reduce the shift shock, it is necessary to synchronize the engine rotational speed with the output rotational speed of the clutch. In Patent Document 1, when the clutch is released (disconnected), the engine rotational speed becomes the target rotational speed after the downshift. The shift shock is suppressed by performing the rotational speed feedback control for controlling the throttle opening so that
JP 2006-112248 A

  In Patent Document 1, the retard control of the engine is started when the deviation between the engine rotational speed and the target rotational speed becomes smaller than a predetermined value. This is because the engine speed overshoots or hunts due to response delays only by controlling the throttle opening, and it is difficult to converge to the target speed. Convergence to rotation speed is improved.

  However, in this configuration, when the deviation between the engine rotational speed and the target rotational speed becomes smaller than a predetermined value, the retard control continues until the end of the shift. For this reason, for example, in a vehicle equipped with an automatic transmission, If there is a malfunction in the transmission hydraulic circuit or if there is a delay in the clutch operation by the driver in a vehicle equipped with a manual transmission, the engine exhaust temperature rises due to continued retard control, and the catalyst temperature May increase and deteriorate the catalyst.

  If the rotation speed synchronization control is interrupted during the shift, the retard control is also interrupted and the catalyst can be protected. However, in this case, the engine rotation speed does not match the target rotation speed, and a shift shock may occur. is there.

  The present invention has been made in view of such technical problems of the prior art, and an object of the present invention is to perform rotational speed synchronization control while protecting a catalyst to reduce shift shock.

In the engine control apparatus according to the present invention, after releasing the clutch, the target rotational speed of the engine is set so that the rotational speed of the engine is synchronized with the output rotational speed of the clutch, and the rotational speed of the engine becomes the target rotational speed. As described above, the rotational speed feedback control for controlling the throttle opening of the engine is performed, and when the deviation between the rotational speed of the engine and the target rotational speed becomes smaller than a predetermined value, retard control of the ignition timing of the engine is performed. And even before the clutch is engaged, if there is a possibility that the catalyst is deteriorated due to an increase in the temperature of the catalyst, the retard control is stopped and the gain of the feedback control is decreased.

According to the present invention, retard control does not continue for a long time even when the shift is not completed with the clutch disengaged, and it is possible to suppress the catalyst temperature from rising and deterioration of the catalyst. it can. Further, only the retard control is stopped, and the rotational speed feedback control by the throttle control is continued, so that a large shift between the engine rotational speed and the target rotational speed is generated at the end of the shift, thereby suppressing the occurrence of a shift shock. be able to.
Further, since the gain of the feedback control is reduced when the retard control is stopped, the hunting of the rotation speed due to the stop of the retard control can be suppressed.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

  FIG. 1 shows a schematic configuration of a vehicle including an engine control device (engine controller 1) according to the present invention.

  A throttle valve 4 is provided in the intake passage 3 of the engine 2. The throttle valve 4 is an electronically controlled throttle valve that can control the opening degree independently of the position of the accelerator pedal 5. A throttle actuator 6 for controlling the opening degree is attached to the throttle valve 4. The exhaust passage 8 of the engine 2 is provided with a catalyst 9 (for example, a three-way catalyst) for purifying exhaust gas.

  The engine 2 is provided with an engine rotation speed sensor 10 for detecting the engine rotation speed Ne and a cooling water temperature sensor 11 for detecting the cooling water temperature Tw. The accelerator pedal 5 has an accelerator pedal position sensor 12 for detecting the accelerator pedal position APP, the throttle valve 4 has a throttle opening sensor 13 for detecting the throttle opening TVO, and the catalyst 9 has a catalyst temperature sensor 14 for detecting the catalyst temperature Tcat. Is attached.

  The output rotation of the engine 2 is shifted by the transmission 15 and transmitted to the transmission output shaft, and is transmitted to drive wheels (not shown). Between the engine output shaft and the transmission input shaft, a clutch 18 that is engaged and disengaged (disconnected) in accordance with the operation of the clutch pedal 17 is interposed. The transmission 15 is a stepped manual transmission capable of switching the gear position according to the operation of the shift lever 19 by the driver, for example, a forward 6-speed forward and 1-reverse manual transmission. The transmission output shaft outputs a vehicle speed sensor 20 that detects the vehicle speed from the output rotation of the transmission 15, and the clutch pedal 17 outputs an ON signal when the depression amount of the clutch pedal 17 is larger than a predetermined depression amount, and an OFF signal when it is small. The clutch pedal switch 21 (ON / OFF characteristics may be reversed) and a shift operation sensor 22 for detecting the operation direction (shift operation) of the shift lever 19 by the driver are attached to the shift lever 19. The predetermined depression amount is usually set larger than the clutch disengagement position so that it can be determined that the clutch 18 has been released reliably.

  Detection values of various sensors are input to the engine controller 1. The engine controller 1 performs fuel injection control and ignition timing control of the engine 2 based on the input detection value.

  Further, the engine controller 1 is configured to synchronize the rotational speed Ne of the engine 2 with the output rotational speed of the clutch 18 when the clutch pedal 17 is depressed to release the clutch 18 and the transmission 15 is shifted. And the shift shock is suppressed when the clutch 18 is re-engaged to complete the shift.

  FIG. 2 is a control block diagram of a portion related to the rotational speed synchronization control of the engine controller 1.

  The engine controller 1 calculates the next gear position (target gear position) from the driver's shift operation (B1), and the output rotation speed of the clutch 18 when the current gear position of the transmission 15 is changed to the target gear position. (= The input rotational speed of the transmission 15 determined according to the vehicle speed VSP and the target gear position) is calculated as the target rotational speed tNe of the engine 2 (B2), and when the rotational speed synchronization control is permitted, the engine 2 Rotational speed feedback control for controlling the throttle opening TVO is performed via the throttle actuator 6 so that the rotational speed Ne becomes the target rotational speed tNe (B3). The rotational speed synchronization control is permitted when the clutch pedal switch 21 is ON, that is, while the clutch pedal 17 is depressed and the clutch 18 is released (B4).

  In the rotational speed feedback control, the engine controller 1 determines the engine torque (rotational speed synchronization control request torque) necessary for making the rotational speed Ne of the engine 2 coincide with the target rotational speed tNe and the rotational speed Ne of the engine 2 and the target rotational speed. Based on the deviation of the speed tNe, for example, it is calculated by PI calculation (proportional integral calculation), and the throttle opening TVO is controlled (throttle control) by the throttle actuator 6 so that this rotational speed synchronous control required torque is realized.

  At this time, with the throttle control alone, hunting occurs due to overshooting of the rotational speed Ne of the engine 2 or delay in response of the throttle actuator 6 or delay of intake air introduced into the engine 2 even after approaching the target rotational speed tNe. Therefore, the engine controller 1 also performs retard control that delays the ignition timing by the ignition device of the engine 2 when the deviation between the rotational speed Ne of the engine 2 and the target rotational speed tNe becomes smaller than a predetermined value ΔN ( B5). The predetermined value ΔN is set to 200 to 300 rpm, for example. By delaying the ignition timing of the engine 2, the torque of the engine 2 can be quickly reduced and the rotational speed Ne can be lowered. Therefore, when used in combination with the throttle control, the rotational speed Ne of the engine 2 can be quickly set to the target rotational speed tNe. It can be converged.

  Further, if the speed change is not completed as in the case where the driver travels with the clutch pedal 17 depressed, the exhaust temperature of the engine 2 rises due to continued retard control, and the catalyst temperature Tcat rises to increase the catalyst 9. May deteriorate. Therefore, the engine controller 1 monitors the elapsed time since the start of the retard control using the retard control permission timer TMrtd, and when the elapsed time exceeds a predetermined time, the catalyst temperature Tcat is set to a predetermined upper limit temperature (= heat resistance). It is determined that there is a possibility that the catalyst 9 is deteriorated by reaching (temperature-margin), and the retard control is terminated. The predetermined time is set to a time at which the catalyst temperature Tcat does not exceed a predetermined upper limit temperature even if the retard control is continuously performed in a situation where the catalyst temperature is high during high load operation or the like. Is set.

  In addition, if the retard control is terminated and only the throttle control is performed, hunting of the rotational speed can occur. Therefore, the feedback gain (proportional gain, integral gain in the case of PI calculation) of the rotational speed feedback control is changed to a smaller value. , Hunting of rotational speed is suppressed.

  FIG. 3 is a flowchart showing details of the rotation speed synchronization control performed by the engine controller 1. The rotational speed synchronization control will be further described with reference to this.

  In step S11, it is determined whether the clutch pedal switch 21 is ON. If it is ON, the rotation speed synchronization control is permitted, and the process proceeds to step S12 and subsequent steps.

  In step S12, a target gear position is calculated. The target gear position is calculated based on the current gear position and the operation direction (shift operation) of the shift lever 19 detected by the shift operation sensor 22.

  In step S13, it is determined whether the retard control is permitted. At the start of the rotation speed synchronization control, the initial setting is made to allow the retard control, and the process proceeds to step S14. In step S14, based on the deviation between the rotational speed Ne of the engine 2 and the target rotational speed tNe, rotational speed feedback control is performed for controlling the throttle opening TVO so that the rotational speed Ne of the engine 2 approaches the target rotational speed tNe. The target rotational speed tNe is set to the output rotational speed of the clutch 18 determined according to the vehicle speed VSP and the target gear position. The feedback gain at this time is set to a high gain, and the rotational speed Ne of the engine 2 is quickly brought close to the target rotational speed tNe.

  In step S15, it is determined whether the deviation between the rotational speed Ne of the engine 2 and the target rotational speed tNe is smaller than a predetermined value ΔN. The predetermined value ΔN is set to 200 to 300 rpm as described above. When the deviation is smaller than the predetermined value ΔN, the retard control is permitted and the process proceeds to step S16. On the other hand, when the deviation between the rotational speed Ne of the engine 2 and the target rotational speed tNe is larger than the predetermined value ΔN, the process returns to step S11, and only the rotational speed feedback control by the throttle control is continued.

  In step S16, ignition timing retard of the engine 2 is executed. As a result, the ignition timing of the engine 2 is delayed so that the rotational speed Ne of the engine 2 does not exceed the target rotational speed tNe, and the rotational speed of the engine 2 is quickly converged to the target rotational speed.

  In step S17, the retard control permission timer TMrtd is counted down in order to measure the elapsed time from the start of the ignition timing retard.

  In step S18, it is determined whether the retard control permission timer TMrtd has become smaller than zero, that is, whether a predetermined time has elapsed since the start of the ignition timing retard. If the predetermined time has elapsed, the catalyst temperature Tcat is increased. Therefore, it is determined that the catalyst 9 may be deteriorated, and the process proceeds to step S19, where the retard control is prohibited and stopped. The retard control permission timer TMrtd is set so that the predetermined time is about 1 second as described above.

  When the retard control is prohibited, the process proceeds from step S13 to step S20, and the feedback gain of the rotational speed feedback control is changed to a low gain smaller than the value set in step S14. Thereby, the hunting of the rotational speed due to stopping the retard control is suppressed.

  Thereafter, when the clutch pedal switch 21 is turned off, the process goes from step S11 to step S21 and the end process is performed. In the termination process, the rotational speed synchronization control is terminated, the retard control at the time of executing the next rotational speed synchronization control is permitted, and the retard control permission timer TMrtd is reset to the initial value.

  FIG. 4 is a time chart showing how the rotation speed synchronization control is performed.

  When the clutch pedal switch 21 is turned on at time t1, the rotational speed synchronization control is permitted, and the rotational speed Ne of the engine 2 is feedback-controlled to the target rotational speed tNe determined according to the target gear position. At this time, since the shift operation is not performed, there is no change in the target gear position and the third speed remains.

  When the shift lever 19 is operated at time t2 and the target gear position changes from the third speed to the second speed, the target rotational speed tNe increases and the rotational speed Ne of the engine 2 also increases accordingly. At this time, the feedback gain is set to a high gain, the throttle opening TVO is quickly increased to increase the engine torque, and the engine rotational speed Ne increases toward the target rotational speed tNe.

  When the deviation between the rotational speed Ne of the engine 2 and the target rotational speed tNe becomes smaller than the predetermined value ΔN, the retard control is started (time t3), and the convergence to the target rotational speed tNe is improved. In addition, the retard control permission timer TMrtd starts counting down simultaneously with the start of the retard control.

  When the retard control permission timer TMrtd becomes zero at time t4 and a predetermined time elapses from the start of the retard control, the catalyst 9 may be deteriorated due to an increase in the catalyst temperature Tcat, so that the retard control is prohibited and stopped. At time t4, the clutch 18 is still disengaged and the shift is not completed. However, the catalyst 9 is prevented from being deteriorated by stopping the retard control. Further, at this time, the feedback gain is switched from the high gain to the low gain, and the hunting of the rotational speed caused by stopping the retard control is suppressed.

  When the clutch pedal switch 21 is turned off at time t5, the rotational speed synchronization control is finished. At this time, the rotational speed Ne of the engine 2 substantially matches the target rotational speed tNe, that is, the rotational speed of the transmission input shaft determined according to the target gear position and the vehicle speed VSP, and the shift shock when the clutch 18 is engaged is suppressed. .

  Then, the effect by this invention is demonstrated.

  The engine control apparatus (engine controller 1) according to the present invention sets the target rotational speed tNe of the engine 2 so that the rotational speed Ne of the engine 2 is synchronized with the output rotational speed of the clutch 18 after releasing the clutch 18. Rotational speed feedback control is performed to control the throttle opening of the engine 2 so that the rotational speed Ne of the engine 2 becomes the target rotational speed tNe. When the deviation between the rotational speed Ne of the engine 2 and the target rotational speed tNe becomes smaller than a predetermined value ΔN, the ignition timing of the engine 2 is retarded, but the catalyst temperature Tcat is increased even before the clutch 18 is engaged. If there is a possibility that the catalyst 9 may deteriorate due to the above, the retard control is stopped.

  Therefore, according to the present invention, the retard control does not continue for a long time and the catalyst temperature Tcat rises even when the shift does not end easily, such as when the driver travels with the clutch pedal 17 depressed. Thus, deterioration of the catalyst 9 can be suppressed. Further, only the retard control is stopped, and the rotational speed feedback control by the throttle control is continued. Therefore, a large shift occurs between the engine rotational speed Ne and the target rotational speed tNe at the end of the shift, causing a shift shock. Can be suppressed. The possibility that the catalyst 9 is deteriorated due to the increase in the catalyst temperature Tcat is determined, for example, when the elapsed time from the start of the retard control reaches a predetermined time.

  In this embodiment, the predetermined time is set to a constant value. However, the change in the rotational speed of the engine 2 before and after the shift determined according to the operating state of the engine 2 at the start of the shift, the catalyst temperature Tcat, and the gear position before and after the shift. The amount may be varied according to the amount (= | the rotational speed Ne of the engine 2 at the start of the shift−the target rotational speed tNe |). For example, as the amount of change in the rotational speed of the engine 2 before and after the shift increases, it takes time to converge to the target rotational speed tNe. Therefore, if the predetermined time is set longer, the rotational speed of the engine 2 before and after the shift is set. Even when the amount of change is large, it can be converged to the target rotational speed tNe, and a good shift feeling can be obtained by suppressing the shift shock.

  The present invention is preferably applied to an engine control device for a vehicle equipped with a manual transmission in which a shift shock is likely to occur due to a driver's driving operation, as in the above embodiment. In this case, the release of the clutch 18 is detected by a clutch pedal switch 21 provided on the clutch pedal 17. However, the present invention is not limited to a vehicle engine control device equipped with a manual transmission, and can also be applied to a vehicle engine control device equipped with an automatic transmission. In this case, the clutch 18 is provided in the transmission, and is a clutch that cuts off rotation input from the engine 2 at the time of shifting (such a clutch is also included in the “clutch that disconnects the connection between the engine and the transmission”). It is possible to suppress the deterioration of the catalyst 9 due to the retard control being continued for a long time, for example, when the engagement of the clutch is delayed due to the malfunction of the transmission hydraulic circuit.

  Further, when the retard control is stopped, the hunting of the rotational speed may occur only by the throttle control, but when the retard control is stopped as in the above embodiment, the feedback gain of the rotational speed feedback control is decreased from the high gain to the low gain. By doing so, it is possible to effectively suppress hunting after the retard control is stopped.

  Next, a second embodiment of the present invention will be described.

  The second embodiment differs from the first embodiment only in the conditions for prohibiting the ignition timing retard, and the others are the same. Therefore, the following description will focus on a configuration different from the first embodiment.

  FIG. 5 is a flowchart showing the contents of the rotational speed synchronization control performed by the engine controller 1, and parts different from those of the first embodiment are surrounded by broken lines. In the second embodiment, instead of measuring the elapsed time from the start of the ignition timing retard control, the catalyst temperature Tcat is read in step S25, and in step S26, the catalyst temperature Tcat is a predetermined upper limit temperature (= heat resistant temperature of the catalyst−). If it exceeds the margin, it is determined that the catalyst 9 may be deteriorated, and the routine proceeds to step S19 to prohibit the retard control.

  According to the second embodiment, it is possible to prevent the catalyst 9 from being deteriorated due to the continued retard control as in the first embodiment. In the first embodiment, the retard control is prohibited and stopped if the retard control continues for a predetermined time even when the catalyst temperature Tcat at the start of the rotational speed synchronous control has a sufficient margin when viewed from the upper limit temperature. However, in the second embodiment, the retard control is continued until the catalyst temperature Tcat reaches the upper limit temperature, and high convergence to the target rotational speed tNe can be maintained for a longer period.

  Although the catalyst temperature Tcat is detected by the catalyst temperature sensor 14 here, the catalyst temperature Tcat estimates the exhaust temperature from the operating state of the engine 2, the amount of heat received by the catalyst 9 from the exhaust, and the reaction heat inside the catalyst 9. The catalyst temperature Tcat may be estimated based on the amount of heat flowing out from the catalyst 9 to the exhaust pipe, the outside air, or the like.

  The embodiment of the present invention has been described above. However, the above embodiment only shows a part of application examples of the present invention, and the technical scope of the present invention is limited to the specific configuration of the above embodiment. Absent.

1 is a schematic configuration diagram of a vehicle including an engine control device (engine controller) according to the present invention. It is a control block diagram of the part regarding the rotational speed synchronous control of an engine controller. It is the flowchart which showed the content of the rotational speed synchronous control which an engine controller performs. It is the time chart which showed a mode when rotation speed synchronous control is performed. 2 shows a second embodiment of the present invention.

Explanation of symbols

1 Engine controller (engine controller)
2 Engine 4 Throttle valve 5 Accelerator pedal 6 Throttle actuator 9 Catalyst 10 Engine rotational speed sensor 12 Accelerator pedal position sensor 14 Catalyst temperature sensor 13 Throttle opening sensor 15 Transmission 17 Clutch pedal 18 Clutch 19 Shift lever 20 Vehicle speed sensor 21 Clutch pedal switch 22 Shift operation sensor

Claims (4)

An engine, a transmission connected to the engine, and provided between the engine and the transmission or in the transmission, and is released when the transmission is shifted to disconnect the engine and the transmission. In a vehicle engine control device comprising a clutch and a catalyst provided in an exhaust passage of the engine,
After releasing the clutch, the target rotational speed of the engine is set so that the rotational speed of the engine is synchronized with the output rotational speed of the clutch, and the engine rotational speed becomes the target rotational speed. Rotational speed feedback control means for controlling the throttle opening of
A retard control means for performing retard control of the ignition timing of the engine when a deviation between the rotational speed of the engine and the target rotational speed is smaller than a predetermined value;
Retard control stop means for stopping the retard control when there is a possibility that the catalyst is deteriorated due to an increase in the temperature of the catalyst even before the clutch is engaged;
Equipped with a,
An engine control apparatus, wherein the feedback control gain is decreased when the retard control is stopped .   2. The engine control device according to claim 1, wherein the retard control stop unit stops the retard control when a predetermined time has elapsed since the start of the retard control.   The engine control device according to claim 1, wherein the retard control stop unit stops the retard control when the temperature of the catalyst reaches a predetermined upper limit temperature.   The transmission is a manual transmission, the clutch is a clutch interposed between the engine and the transmission, and the clutch pedal is provided to release the clutch, and the operation amount of the clutch pedal is predetermined. The engine control device according to any one of claims 1 to 3, wherein the detection is performed by a switch that is turned on or off when the amount of operation is equal to or greater than an operation amount.