JP5343987B2 - Control device for internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To restrain operability from being deteriorated by a torque level difference by an inertia change when fastening an electromagnetic clutch. <P>SOLUTION: The control device includes a mechanical supercharger 19 for transmitting driving force from an internal combustion engine 1 via the electromagnetic clutch 23, and sets a fastening engine speed R for driving the supercharger 19 by fastening the electromagnetic clutch 23 to be lower as the gear ratio of a manual transmission becomes larger. When the manual transmission is shifting, when the engine speed becomes a fastening engine speed R1 or more for fastening the electromagnetic clutch when the gear ratio of the manual transmission is the largest, the electromagnetic clutch 23 is fastened. <P>COPYRIGHT: (C)2012,JPO&amp;INPIT

Description

  The present invention relates to a control device for an internal combustion engine provided with a mechanical supercharger.

  Patent Document 1 includes an internal combustion engine that includes a mechanical supercharger to which driving force is transmitted from a crankshaft via an electromagnetic clutch, and that drives the supercharger by fastening the electromagnetic clutch when the engine speed increases. , The engine speed is relatively lower when the gear position of the transmission is on the low gear side (the gear ratio is larger) than when the gear position of the transmission is on the high gear side (the gear ratio is lower). A technique is disclosed in which the electromagnetic clutch is engaged at a (relatively low engagement engine speed).

JP 60-153426 A

  However, in Patent Document 1, in the case of downshifting by operating the transmission, when the gear ratio is increased by downshifting, the engagement engine speed at which the electromagnetic clutch is to be engaged in the state after downshifting is: In the state before the downshift, the speed becomes lower than the engagement engine speed at which the electromagnetic clutch is to be engaged.

  Therefore, if the engine speed is much higher than the engine speed when the downshift is completed, the electromagnetic clutch will be engaged with the engine speed higher than the engine speed. Compared to the case where the electromagnetic clutch is engaged when the number reaches the engagement engine speed, especially when the transmission is a manual variable transmission, the torque step due to the inertia change at the time of engagement of the electromagnetic clutch is increased and the operability is improved. May get worse.

Therefore, the present invention has a mechanical supercharger to which the driving force from the internal combustion engine is transmitted via an electromagnetic clutch, and the electromagnetic clutch is engaged to increase the speed ratio of the manual transmission. In the control device for the internal combustion engine set to lower the fastening engine speed for driving the feeder, when the manual transmission is changing speed and the engine speed is higher than a preset predetermined speed, The electromagnetic clutch is engaged, and the predetermined rotation speed is set to a minimum engagement engine rotation speed at which the electromagnetic clutch is engaged when the gear ratio of the manual transmission is the largest .

  According to the present invention, during the shifting of the manual transmission, the electromagnetic clutch is engaged when the engine speed is higher than the predetermined rotational speed. Therefore, as compared with the case where the electromagnetic clutch is engaged with the engine speed being high after the shift. In addition, it is possible to reliably suppress the occurrence of a shock caused by a torque step due to an inertia change when the electromagnetic clutch is engaged.

BRIEF DESCRIPTION OF THE DRAWINGS Explanatory drawing which showed typically the outline of the system configuration | structure of the internal combustion engine to which this invention was applied. Explanatory drawing which showed the action | operation area | region of the electromagnetic clutch. The timing chart which showed the change of various parameters at the time of gear shifting. The flowchart which shows the flow of control regarding fastening / release of an electromagnetic clutch.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is an explanatory view schematically showing an outline of a system configuration of an internal combustion engine 1 to which the present invention is applied.

An intake passage 4 is connected via an intake valve 3 and an exhaust passage 6 is connected via an exhaust valve 5 to the combustion chamber 2 of the internal combustion engine 1 mounted on the passenger car. A spark plug 7 is arranged at the center top of the combustion chamber 2. A fuel injection valve 8 that directly injects fuel into the combustion chamber 2 is disposed on the side of the combustion chamber 2 on the intake valve 3 side. The fuel that is adjusted to a predetermined pressure by the high-pressure fuel pump 9 or the like is supplied to the fuel injection valve 8 through the high-pressure fuel passage 10.

  In the exhaust passage 6, a catalytic converter 11, a second catalytic converter 12, and a silencer (muffler) 13 are provided in order from the upstream side.

  An air flow meter 14 for detecting the amount of intake air is disposed in the intake passage 4, and a throttle valve 15 is disposed at a position downstream of the air flow meter 14. 1 is an intake collector located on the downstream side of the throttle valve 15, and 17 is an air cleaner located on the upstream side of the air flow meter 14.

  The throttle valve 15 includes an actuator 15a made of an electric motor, and is controlled so as to obtain a target throttle opening by driving the actuator 15a in accordance with a control signal given from the control unit 30. In this embodiment, the valve opening (throttle opening) of the throttle valve 15 is detected by a throttle valve opening sensor 15b built in the throttle valve 15.

  In the intake passage 4, an atmospheric pressure sensor 18, a supercharger 19, an intercooler 20, and a supercharging pressure sensor 21 are disposed between the air flow meter 14 and the throttle valve 15 in order from the upstream side.

  The atmospheric pressure sensor 18 is located upstream of the supercharger 19 and detects atmospheric pressure. The supercharging pressure sensor 21 is located downstream of the turbocharger 19 and upstream of the throttle valve 15. The pressure (supercharging pressure) is detected.

  The supercharger 19 is a mechanical supercharger (so-called supercharger) driven by the crankshaft 22 of the internal combustion engine 1, and transmits / cuts off the driving force from the crankshaft 22, but includes an electromagnetic clutch 23. Yes. The electromagnetic clutch 23 is engaged / released according to the operating state, and when engaged, the rotor 19a of the supercharger 19 is rotated by the driving force from the crankshaft 22 to pump the intake air downstream. During the release, the driving force from the crankshaft 22 is not transmitted and the rotor 19a does not rotate.

  A bypass passage 24 that bypasses the supercharger 19 and the intercooler 20 and flows intake air is connected to the intake passage 4. The bypass passage 24 is provided in parallel with the supercharger 19 and the intercooler 20. One end of the bypass passage 24 is connected to the intake passage 4 on the downstream side of the intercooler 20, and the other end is upstream of the supercharger 19. It is connected to the intake passage 4 on the side. A bypass valve 25 is disposed in the bypass passage 24.

  The bypass valve 25 includes an actuator 25a composed of an electric motor, and is controlled so as to obtain a target bypass valve opening degree by driving the actuator 25a in accordance with a control signal given from the control unit 30. The bypass valve 25 fully opens the valve opening degree (bypass valve opening degree) of the bypass valve 25 by using the elastic force of the spring when power is not supplied to the actuator 25a from the in-vehicle battery (not shown). It is comprised so that. In the present embodiment, the bypass valve opening is detected by a bypass valve opening sensor 25b built in the bypass valve 25.

In addition to the detection signals from the air flow meter 14, the atmospheric pressure sensor 18 and the supercharging pressure sensor 21, the control unit 30 includes a crank angle sensor 26 that detects an engine speed (engine speed) and a crank angle position, and a driver. Detection signals of various sensors such as an accelerator opening sensor 27 for detecting the amount of depression of the accelerator pedal (accelerator opening) to be operated and a water temperature sensor 28 for detecting the cooling water temperature of the internal combustion engine 1 are input, and are mounted on the vehicle. voltage information on such a battery (not shown) are also input.

  The control unit 30 controls the fuel injection amount, fuel injection timing, ignition timing, and the like of the internal combustion engine 1 based on these various detection signals that are input, and also controls the throttle opening, bypass valve opening, The driving / stopping of the feeder 19 (engagement / release of the electromagnetic clutch 23) or the like is determined.

  A manual transmission (not shown) is connected to the output side of the internal combustion engine 1 via a clutch (not shown).

  The clutch is engaged / released by a driver's operation of a clutch pedal (not shown) and released when the clutch pedal is depressed. The clutch pedal operation is detected by the clutch pedal switch 32. The clutch pedal switch 32 outputs an ON / OFF signal according to the position of the clutch pedal. The clutch pedal switch 32 is turned on when the clutch is released (when the clutch pedal is depressed), and turned off in other states. .

  The gear position of the manual transmission is changed by a driver's shift lever operation. The position of a shift lever (not shown) is detected by a shift position sensor 33, and the gear ratio of the manual transmission is determined from this shift lever position. Further, the neutral switch 34 can determine whether or not the shift lever is in the neutral position.

  Signals from the clutch pedal switch 32, the shift position sensor 33, and the neutral switch 34 are also input to the control unit 30.

In the present embodiment, since the driving force is transmitted from the crankshaft 22 to the supercharger 19 via the electromagnetic clutch 23, it is necessary to drive the supercharger 19 with the operating state of the internal combustion engine 1 at a low rotation and a low load. when there is no, achieving fuel efficiency by friction reduction by releasing the electromagnetic clutch 23, which is engaged electromagnetic clutch 23 when the or engine speed when there is high load operation request becomes high.

  Here, when the electromagnetic clutch 23 is engaged, the rotor 19a of the supercharger 19 rotates and the inertia changes. However, when the transmission is a manual transmission, this inertia change causes a torque step. As a result, the drivability may be deteriorated.

  Since the torque step generated when the electromagnetic clutch 23 is engaged tends to increase as the engine speed increases, the electromagnetic clutch 23 may be engaged when the engine speed is low in order to improve drivability. However, if the engine speed at which the electromagnetic clutch 23 is engaged is lowered, the effect of reducing the friction obtained by releasing the electromagnetic clutch 23 is reduced.

  Therefore, in the present embodiment, the engagement engine speed R, which is a condition for engaging the electromagnetic clutch 23 so as not to generate a torque step, is set to the transmission ratio of the manual transmission ratio and the driving force in the manual transmission. It is determined according to the state (whether or not shifting is in progress).

  Specifically, as shown in FIG. 2, the maximum torque of the internal combustion engine 1 (characteristic in FIG. 2) obtained when the bypass valve 25 is fully opened and the throttle opening is fully opened in the state where the electromagnetic clutch 23 is released. In the operation region (region below the characteristic line A in FIG. 2) in which the output (target torque) required for the internal combustion engine 1 is smaller than the line A), the gear ratio of the manual transmission, The engagement engine speed R is determined in consideration of the transmission state of the driving force (whether or not shifting is in progress) and the vehicle speed. The target torque is calculated using the detection value of the accelerator opening sensor 27 or the like.

  In the operation region in which the target torque is larger than the characteristic line A in FIG. 2, the supercharge region in which the supercharger 19 is driven by engaging the electromagnetic clutch 23 is set regardless of the engine speed. A characteristic line B in FIG. 2 represents the maximum torque of the internal combustion engine 1 obtained when the bypass valve 25 is fully closed and the throttle opening is fully opened in the state where the electromagnetic clutch 23 is engaged.

  When the operating state of the internal combustion engine 1 is in a region below the characteristic line A in FIG. 2, the electromagnetic clutch 23 is engaged if the vehicle speed is in a low vehicle speed state where the vehicle speed is equal to or lower than a predetermined speed set in advance. Since the drivability does not deteriorate due to the torque step (no shock is generated), a predetermined rotation speed Ra set in advance considering the component durability of the electromagnetic clutch 23 is set as the engagement engine rotation speed R. To do. The predetermined rotational speed Ra (fastening engine speed Ra) is at least equal to or higher than the fastest engine speed R (fastening engine speed R4 described later in the present embodiment) when the gear ratio of the manual transmission is the smallest. In this embodiment, it is set so as to be the engagement engine speed R when the gear ratio of the manual transmission is the smallest (in this embodiment, the engagement engine speed R4 described later). Has been.

  In the case of a low vehicle speed, the engine speed is low if the clutch between the internal combustion engine 1 and the manual transmission is engaged, and when the electromagnetic clutch 23 is engaged regardless of the gear ratio of the manual transmission. The generated torque step is reduced. Further, in the case of a low vehicle speed, when the engine speed is high, the slip amount of the clutch between the internal combustion engine 1 and the manual transmission increases, so that the electromagnetic wave is not affected regardless of the gear ratio of the manual transmission. A torque step generated when the clutch 23 is engaged is reduced.

  Then, when the operating state of the internal combustion engine 1 is in the region below the characteristic line A in FIG. 2, when it is not the low vehicle speed state described above, the engine speed is determined by whether or not the manual transmission is shifting. Switch the calculation method of R.

  In the present embodiment, whether or not the manual transmission is shifting is determined based on signals from the clutch pedal switch 32, the neutral switch 34, and the like. For example, if the clutch pedal is depressed, It is determined that shifting is in progress. In the case where the gear ratio of the manual transmission is estimated from the engine speed and the vehicle speed, it is determined that the state in which the estimation of the gear ratio of the manual transmission has not been determined is being shifted. Also good.

  If the manual transmission is not shifting, the fastening engine speed R is set to be lower as the gear ratio of the manual transmission increases. In the present embodiment, the manual transmission has four shift speeds on the forward side, the engagement engine speed when the shift speed is the first speed is R1, and the engagement engine speed when the speed is the second speed is R2. If the engagement engine speed when the speed is 3rd is R3 and the engagement engine speed when the speed is 4th is R4, R1 to R4 are R1 <R2 <R3 <R4. .

  If the manual transmission is shifting, the engagement engine speed R is set to the engagement engine speed R1 when the shift speed is the first speed. That is, if the manual transmission is shifting, the engagement engine speed R is set to the engagement engine speed when the gear ratio of the manual transmission is the largest (the engagement engine speed R1 when the shift speed is the first speed). Set to.

  FIG. 3 is a timing chart showing changes in various parameters at the time of shifting of the manual transmission, and the shift stage of the manual transmission is changed from the third speed to the second speed while the electromagnetic clutch 23 is released. The case where it shifted down is shown.

  Prior to timing t1, the engine speed is lower than the engaged engine speed R3 when the gear stage is in the third speed, and a clutch release command is output to the electromagnetic clutch 23.

  When the driver depresses the clutch pedal, it is determined that the manual transmission is shifting (timing t1), and the engagement engine speed R is switched to the engagement engine speed R1 when the shift speed is the first speed. . Then, at the timing t1, the engagement engine speed R becomes smaller and the engine speed becomes higher than the engagement engine speed R, so that a clutch engagement command is output to the electromagnetic clutch 23.

  At the timing t2, the gear position is set to the neutral position by the driver operating the shift lever. At the timing t3, the gear position is switched to the second speed.

  Then, the clutch of the manual transmission is gradually engaged while returning the clutch pedal, and the clutch pedal is not depressed at the timing t3, and it is determined that the manual transmission is not shifting. The fastening engine speed R is switched to the fastening engine speed R2 when the shift speed is the second speed. Even after t3, the engine speed is higher than the engaged engine speed R2, so that the electromagnetic clutch 23 remains engaged.

  When the electromagnetic clutch 23 is engaged during the shifting of the manual transmission, but the engine speed becomes lower than the engaged engine speed R after the shifting of the manual transmission is completed, the electromagnetic clutch is set after the shifting is completed. 23 will be released.

  As indicated by the one-dot chain line in FIG. 3, when the electromagnetic clutch 23 is to be engaged at the timing t3 after the end of the shift of the manual transmission, the engine speed is changed from that before the shift by shifting when the electromagnetic clutch 23 is shifted down. As the engine speed R rises, the engine speed R of the fastening engine also becomes relatively low. Therefore, the engine speed is higher than the engine speed R of the fastening engine, and the speed difference becomes large. When fastened, the torque step becomes large and the drivability deteriorates.

On the other hand, in this embodiment, if the manual transmission is shifting, the engagement engine speed R is set to the engagement engine speed R1 when the gear ratio of the manual transmission is the largest. When the electromagnetic clutch 23 is engaged after the manual transmission is completed, the electromagnetic clutch 23 is always engaged during the shifting of the manual transmission.

  Therefore, compared with the case where the electromagnetic clutch 23 is engaged with the engine speed being high after the manual transmission is finished, the occurrence of a shock caused by a torque step due to the inertia change when the electromagnetic clutch 23 is engaged is surely suppressed. be able to. In addition, when the manual transmission is being shifted, the clutch between the internal combustion engine 1 and the manual transmission is released, and therefore, the influence of the torque step on the drivability due to the inertia change when the electromagnetic clutch 23 is engaged. Becomes smaller.

  Since the calculation method of the engagement engine speed R is switched depending on whether or not the manual transmission is shifting, it is possible to improve fuel efficiency by reducing friction and to improve drivability when the electromagnetic clutch 23 is engaged. Both can be achieved.

  The engagement engine speed R set when the vehicle speed is low is a predetermined speed Ra set in consideration of the durability of the electromagnetic clutch 23, and the gear ratio of the manual transmission is the highest. Since the engine speed is set to be equal to or higher than the engagement engine speed R when it is small, it is advantageous in improving fuel consumption by reducing friction.

  FIG. 4 is a flowchart showing a flow of control related to engagement / release of the electromagnetic clutch 23 executed by the control unit 30 in the above-described embodiment. This process by the control unit 30 is repeatedly performed every predetermined time (for example, every 10 ms).

  In S1, it is determined whether or not the accelerator opening is greater than or equal to a predetermined opening. If the accelerator opening is greater than or equal to the predetermined opening, the supercharger 19 is driven to achieve the target torque required by the driver. Since it is necessary to proceed to S2, the electromagnetic clutch 23 is engaged, and if the accelerator opening is not greater than the predetermined opening, the process proceeds to S3.

  In S3, it is determined whether or not the vehicle speed is in a low vehicle speed state where the vehicle speed is equal to or lower than a predetermined speed set in advance. If the vehicle speed state is low, the process proceeds to S4, and if not, the process proceeds to S7.

  In S4, it is determined whether or not the engine speed is higher than the fastening engine speed Ra set in consideration of the component durability of the electromagnetic clutch 23. If the engine speed is higher, the process proceeds to S5 and proceeds to S5. If the electromagnetic clutch 23 is in the engaged state, the electromagnetic clutch 23 is released.

  In S7, it is determined whether or not the manual transmission is shifting. If the shifting is in progress, the process proceeds to S8. If not, the process proceeds to S12.

  In S8, the engagement engine speed R1 when the gear ratio of the manual transmission is maximum (when the gear position is 1st) is set as the engagement engine speed R, and the process proceeds to S9.

  In S9, it is determined whether or not the engine speed is higher than the engagement engine speed R1, and if it is higher, the process proceeds to S10 to engage the electromagnetic clutch 23, and if it is lower, the process proceeds to S11. Is engaged, the electromagnetic clutch 23 is released.

  In S12, the engagement engine speed R is calculated according to the gear ratio of the manual transmission, and the process proceeds to S13.

  In S13, it is determined whether or not the engine speed is higher than the engagement engine speed R calculated in accordance with the gear ratio of the manual transmission. If the engine speed is higher, the process proceeds to S14 and the electromagnetic clutch 23 is turned on. If the electromagnetic clutch 23 is in the engaged state, the electromagnetic clutch 23 is released if the electromagnetic clutch 23 is engaged.

DESCRIPTION OF SYMBOLS 1 ... Internal combustion engine 4 ... Intake passage 15 ... Throttle valve 15a ... Actuator 15b ... Throttle valve opening sensor 18 ... Atmospheric pressure sensor 19 ... Supercharger 20 ... Intercooler 21 ... Supercharging pressure sensor 22 ... Crankshaft 23 ... Electromagnetic clutch 24 ... Bypass passage 25 ... Bypass valve 25a ... Actuator 25b ... Bypass valve opening sensor 30 ... Control unit

Claims (3)

A control device for an internal combustion engine mounted on a vehicle having a manual transmission, comprising a mechanical supercharger to which a driving force from the internal combustion engine is transmitted via an electromagnetic clutch, and the shift of the manual transmission In the control device for an internal combustion engine that is set so that the engagement engine speed for engaging the electromagnetic clutch and driving the supercharger decreases as the ratio increases.
When the manual transmission is changing speed and the engine speed is higher than a preset predetermined speed, the electromagnetic clutch is engaged ,
The control apparatus for an internal combustion engine, wherein the predetermined rotational speed is set to a minimum engagement engine rotational speed that engages the electromagnetic clutch when the gear ratio of the manual transmission is the largest . Vehicle speed detecting means for detecting the vehicle speed;
When the vehicle speed is a predetermined speed or less which is set in advance, according to claim 1, as compared with the case where the vehicle speed is greater than a predetermined speed set in advance, and changes the engagement engine speed to a high rotation side The control apparatus of the internal combustion engine described in 1. When the vehicle speed is higher than a preset predetermined speed, the electromagnetic clutch is engaged when the manual transmission is shifting and the engine speed is higher than the preset predetermined speed. If not during gear shifting, the higher the gear ratio of the manual transmission, the lower the engine speed is set to be lower,
When the vehicle speed is equal to or lower than a predetermined speed set in advance, at least when the engine speed becomes equal to or higher than the maximum engagement engine speed at which the electromagnetic clutch is engaged when the gear ratio of the manual transmission is the smallest. The control device for an internal combustion engine according to claim 2 , wherein an electromagnetic clutch is engaged.

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