JP4383155B2 - Deceleration control device and deceleration control method for internal combustion engine - Google Patents

Description

  The present invention relates to deceleration control of an internal combustion engine during vehicle deceleration.

Patent Document 1 includes a mechanism for changing the opening / closing timing of an intake valve of an internal combustion engine (that is, a phase with respect to a crank angle) and a continuously variable transmission, and changing a gear ratio during vehicle deceleration accompanied by a fuel cut. A technique for eliminating the decrease in the vehicle deceleration feeling due to the change in the opening / closing timing is disclosed. That is, since the engine brake becomes excessive when the gear ratio increases, the opening / closing timing (particularly the closing timing) of the intake valve is changed to reduce the pumping loss.
JP 2001-341554 A

  Although the problem of vehicle deceleration force (coast-down acceleration) can be solved to some extent by reducing the pumping loss as in Patent Document 1 above, the intake into the cylinder of the engine can be achieved simply by changing the closing timing of the intake valve. When the amount of air to be reduced is extremely reduced and fuel injection is restarted next time, there is a risk of causing deterioration of combustion including misfire and the like.

  By the way, in an engine, in particular, an engine using gasoline as a fuel, the output characteristics greatly depend on the intake air amount. As a device for adjusting the intake air amount, there is a variable valve mechanism that makes the operation characteristics of the intake valve variable in addition to a known throttle that opens and closes the intake passage. As this variable valve mechanism, in addition to the phase variable mechanism that makes the center phase of the intake valve operating angle with respect to the crank angle variable, an operating angle variable mechanism that makes the operating angle of the intake valve variable is known. ing.

  An object of the present invention is to realize a smooth and comfortable deceleration feeling by appropriately controlling the throttle, the phase variable mechanism, and the operating angle variable mechanism during vehicle deceleration.

A variable operating angle mechanism that varies the size of the operating angle of the intake valve, a variable phase mechanism that varies the central phase of the operating angle of the intake valve with respect to the crank angle, an electronically controlled throttle that opens and closes the intake passage, Coordinated control for controlling the throttle, the operating angle, and the closing timing of the intake valve by controlling the operation of the throttle, the operating angle variable mechanism, and the phase variable mechanism according to a decrease in the vehicle speed during vehicle deceleration. Means . The cooperative control means is set in advance on the basis of the vehicle speed and the engine rotational speed, and the first region on the high vehicle speed side where the required value of the deceleration acceleration corresponding to the deceleration torque required for the internal combustion engine is large. A second region where the required value of the deceleration acceleration is smaller than the second region, and a third region where the required value of the deceleration acceleration is smaller than the second region. The first region and the second region on the lower vehicle speed side than the first region are divided by a first boundary characteristic in which the engine rotational speed decreases as the vehicle speed decreases, and the second region The region and the third region on the vehicle speed side lower than the second region are classified by a second boundary characteristic in which the engine rotational speed decreases as the vehicle speed decreases. In the first region, when the throttle opening is decreased and the operating angle of the intake valve is increased, and the vehicle shifts from the first region to the second region in response to a decrease in vehicle speed during the vehicle deceleration, When the throttle opening is increased and the intake valve operating angle is decreased as compared with the region 1 and the vehicle speed is reduced during the vehicle deceleration, the second region is shifted to the third region. As compared with the second region, the throttle opening is increased and the closing timing of the intake valve is advanced before the bottom dead center .
Alternatively, the cooperative control means has first to third areas preset for deceleration acceleration and vehicle speed obtained by multiplying the engine rotation speed and the gear ratio, and the first area on the high vehicle speed side, The second region on the vehicle speed side lower than the first region is classified by the first boundary characteristic in which the deceleration acceleration decreases as the vehicle speed decreases, at least when the vehicle speed is higher than a predetermined value. The second region and the third region on the lower vehicle speed side than the second region are at least a second boundary where the deceleration acceleration decreases as the vehicle speed decreases when the vehicle speed is greater than a predetermined value. In the first region, the throttle opening is reduced and the intake valve operating angle is increased. From the first region to the second region as the vehicle speed decreases during the vehicle deceleration. The first If the throttle opening is increased and the operating angle of the intake valve is reduced compared to the region, and the vehicle shifts from the second region to the third region in response to a decrease in vehicle speed during the vehicle deceleration, Compared with the region 2, the throttle opening is increased, and the closing timing of the intake valve is advanced before the bottom dead center.

  According to the present invention, the deceleration acceleration and the intake air amount of the internal combustion engine can be reduced smoothly during vehicle deceleration, and a smooth and comfortable feeling of deceleration can be realized. Further, during deceleration of the vehicle with fuel cut, the intake air amount does not decrease excessively, and stable combustibility can be obtained even at the next fuel injection due to a reacceleration request, for example.

  Hereinafter, an embodiment in which a deceleration control apparatus for an internal combustion engine according to the present invention is applied to a spark ignition gasoline engine for an automobile will be described.

  FIG. 1 is an explanatory diagram showing a variable valve mechanism that changes the operating characteristics of an intake valve of an internal combustion engine. Each cylinder is provided with a pair of intake valves 11, and a drive shaft 2 that rotates in conjunction with the crankshaft is disposed above the valve lifter 10 of the intake valves 11. The variable valve mechanism is a lift / operating angle variable mechanism (VEL) 1 that can continuously and continuously change the valve lift amount and operating angle of the intake valve, and the center of the operating angle of the intake valve with respect to the crank angle. A phase variable mechanism 21 for advancing or retarding the phase is combined.

  The lift / operating angle variable mechanism 1 has been previously proposed by the applicant of the present invention. However, since it has been publicly known, for example, in Japanese Patent Application Laid-Open No. 11-107725, only the outline thereof will be described. The variable lift / operating angle mechanism 1 includes a control shaft 12, a control eccentric shaft portion 18 provided eccentric to the control shaft 12, a rocker arm 6 fitted to the control eccentric shaft portion 18 so as to be swingable, and a drive. A drive eccentric shaft portion 3 provided eccentric to the shaft 2, a swing cam 9 slidably fitted to the drive shaft 2, and a ring-shaped first connecting the drive eccentric shaft portion 3 and one end of the rocker arm 6. One link 4 and a second link 8 that links the other end of the rocker arm 6 and the tip of the swing cam 9 are provided. Similarly to the drive shaft 2, the control shaft 12 is rotatably supported by an engine fixing element such as a cylinder block, and the rotation angle position is changed and held by the operating angle actuator 13 via the worm gear 15. The first link 4 is rotatably fitted to the circular outer periphery of the drive eccentric shaft portion 3. One end of the rocker arm 6 and the tip of the first link 4 are rotatably connected by a first connecting pin 5. The other end of the rocker arm 6 and one end of the second link 8 are rotatably connected by a second connecting pin 7. The other end of the second link 8 and the tip of the swing cam 9 are rotatably connected by a third connecting pin 17.

  When the drive shaft 2 rotates in conjunction with the crankshaft, the rocker arm 6 swings through the drive eccentric shaft portion 3 and the first link 4, and the rocking motion of the rocker arm 6 swings through the second link 8. The oscillation cam 9 is oscillated by being transmitted to the cam 9. When the swing cam 9 that swings comes into contact with and presses the valve lifter 10 provided above the intake valve 11, the intake valve 11 opens and closes against the valve spring reaction force. When the rotational position of the control shaft 12 is changed by the operating angle actuator 13, the center position of the control eccentric shaft portion 18 that is the swing fulcrum of the rocker arm 6 changes. As a result, the swing range of the swing cam 9 is changed, and the valve lift amount of the intake valve 11 (with the center phase of the operating angle of the intake valve 11 with respect to the crank angle (rotational position of the crankshaft) remains substantially constant. Both the maximum lift) and the operating angle change continuously and steplessly. The control state of the lift / operating angle variable mechanism 1 is detected by a control shaft sensor 14 that responds to the rotational position of the control shaft 12.

  Such a variable lift / operating angle mechanism 1 has the following specific effects in addition to being able to continuously change both the valve lift amount and the operating angle of the intake valve 11. Since many of the connecting parts of each link element are in surface contact, lubrication is easy and reliability and durability are excellent. Since there is no need to use an urging means such as a return spring, the structure is simple, the loss is small, and the reliability and durability are excellent. The drive shaft 2 and the swing cam 9 can be arranged at almost the same position as the cam shaft and fixed cam of the existing direct acting valve system, and the layout is greatly increased compared to the internal combustion engine of the direct acting valve system. It can be easily applied without changing.

  The phase variable mechanism 21 includes a sprocket 22 provided at the front end of the drive shaft 2 and a phase actuator 23 that relatively rotates the sprocket 22 and the drive shaft 2 within a predetermined angle range. . The sprocket 22 rotates around an axis in synchronization with the crankshaft via a timing chain or timing belt (not shown). The phase actuator 23 is composed of, for example, a rotary actuator such as a hydraulic type or an electromagnetic type, and operates according to a control signal from an engine control unit 19 described later. By the action of the phase actuator 23, the sprocket 22 and the drive shaft 2 rotate relatively, and the center phase (opening / closing timing) of the operating angle of the intake valve 11 with respect to the crank angle is retarded / advanced. That is, the lift characteristic curve itself does not change, and the whole advances or retards. This change can also be obtained continuously. The control state of the phase variable mechanism 21 is detected by the drive shaft sensor 16 that responds to the rotational position of the drive shaft 2.

  FIG. 2 is a system configuration diagram of the intake system of the internal combustion engine. An electronically controlled throttle (valve) 27 that opens and closes the intake passage 25 is provided upstream of the collector 26 in the intake passage 25. In this internal combustion engine, the intake air supplied to the combustion chamber 28 of the cylinder is controlled by combining the throttle 27, the lift / operating angle variable mechanism 1 and the phase variable mechanism 21 described above. Yes. That is, the engine control unit 19 detects the vehicle speed detected by the vehicle speed sensor 30, the gear ratio of the continuously variable transmission 31, the accelerator signal detected by the accelerator opening sensor 32, and the engine speed detected and calculated by the rotational speed sensor 33. Based on input signals representing various engine operating conditions such as speed (number of rotations), rotational position of the drive shaft 2 detected by the drive shaft sensor 16, and rotational position of the control shaft 12 detected by the control shaft sensor 14. Then, command signals are output to the throttle 27, the operating angle actuator 13 and the phase actuator 23, and the operations of the throttle 27, the lift / operating angle variable mechanism 1 and the phase variable mechanism 21 are controlled. The control of the lift / working angle variable mechanism 1 and the phase variable mechanism 21 is not limited to the closed loop control based on the detection of the sensors 14 and 16, but may be simply open loop control according to the operating conditions. As is well known, the engine control unit 19 outputs a control signal to the spark plug 34 and the fuel injector 35 based on the engine operating state, and controls the ignition timing, the fuel injection amount, and the fuel injection timing. The continuously variable transmission 31 can change the gear ratio steplessly and continuously, and a belt type or a toroidal type is known, and the description thereof is omitted here.

  FIG. 3 is a time chart during vehicle deceleration. In the first embodiment of the present invention, during deceleration of the vehicle, the throttle 27, the lift / operating angle variable mechanism 1 and the phase variable mechanism 21 are appropriately combined in accordance with the required value of the deceleration acceleration of the internal combustion engine. Control. FIG. 4 is a flowchart showing the flow of deceleration control of the internal combustion engine according to the first embodiment. This routine is repeatedly executed by the engine control unit 19 every predetermined period.

  In step (denoted as S in the figure) 1, it is calculated whether a predetermined vehicle deceleration is in progress. For example, when it is detected that the vehicle is decelerating with fuel cut, such as when the vehicle is traveling and the accelerator opening is 0 (zero), step 1 is affirmed.

  In step 2, a required value TG of deceleration acceleration (deceleration G) corresponding to the deceleration torque required for the internal combustion engine is calculated. Specifically, based on the vehicle speed detected by the sensors 30 and 33 and the engine speed, the control map of FIG. 5 set and stored in advance is searched to calculate the required value TG.

  In step 3, it is determined whether the required value TG is in a predetermined required area α2, a required large area α1, which is larger than the required area α2, or a required small area α3 which is smaller than the required area α2. judge. Specifically, the respective regions α1, α2, and α3 are set in advance in the control map of FIG. 5, and it is directly determined which region the required value TG is in based on the vehicle speed and the engine speed. Search for.

  If it is determined that the requested large region α1, the process proceeds to step 4. In the required large area α1, the opening degree of the throttle 27 is reduced, the operating angle of the intake valve is increased, and the central phase of the operating angle of the intake valve is retarded as compared to the required area α2. Specifically, as shown in FIG. 3, the throttle 27 is fully closed, the intake valve opening timing IVO is advanced from the top dead center TDC, and the closing timing IVC is retarded from the bottom dead center BDC. Then, the operating angle and the center phase are set. The pumping loss due to the throttle 27 being fully closed and the pumping loss due to the opening angle of the intake valve being increased by increasing the operating angle can increase the pumping loss and ensure sufficient deceleration acceleration.

  If it is determined that the requested area α2, the process proceeds to step 5. In the requested middle region α2, as compared with the requested large region α1, the opening degree of the throttle 27 is mainly increased and the operating angle of the intake valve is decreased. Further, the central phase is advanced (however, a retard angle is set as compared with a required small area α3 described later). Specifically, as shown in FIG. 3, the throttle opening is set to a predetermined small opening, the intake valve opening timing is near the top dead center TDC, and the intake valve closing timing is lower than the bottom dead center BDC. The operating angle and the center phase are set so that the angle is greatly advanced. The operating angle is set to the minimum value or the vicinity thereof. As a result, the suction negative pressure can be reduced while suppressing the pumping loss as compared with the required large region α1.

  If it is determined to be the required small area α3, the process proceeds to Step 6. In the required small region α3, the central phase of the operating angle of the intake valve is advanced while mainly increasing the throttle opening as compared with the required region α2. Specifically, as shown in FIG. 3, the throttle opening is set to a predetermined medium opening, the closing timing of the intake valve is advanced from the top dead center TDC, and the closing timing is further from the bottom dead center. The operating angle and the center phase are set so that the angle is greatly advanced. The pumping loss can be further reduced by reducing the pumping loss by increasing the throttle opening and by reducing the pumping loss by shortening the opening period of the intake valve by reducing the operating angle. In this embodiment, when the intake valve closing timing IVC is advanced, the center phase of the intake valve operating angle is advanced by the phase variable mechanism 21, so that by expanding the overlap region with the exhaust valve, The pumping loss can be further reduced without changing the operating angle substantially to the lower side as compared with the requested area α2.

  According to the first embodiment, as shown in FIG. 3, during deceleration of the vehicle, the required value TG of the deceleration acceleration is typically changed from the requested large area α1 to the requested area α2 mainly according to the decrease in the vehicle speed. → Transition proceeds in the order of the required small area α3. As a result, at the initial stage of deceleration where the vehicle speed is still high, the required large region α1 is selected, and the intake air amount is excessively decreased by closing the throttle, increasing the intake operating angle, and delaying the center phase. In addition, the necessary deceleration acceleration can be quickly secured by positively increasing the pumping loss. After that, when the vehicle decelerates and the mid-deceleration is reached, the requested middle region α2 is selected, and the suction negative pressure is reduced while reducing the pumping loss well by mainly opening the throttle and reducing the operating angle of the intake valve. Can continue. When the vehicle deceleration further increases and the gear ratio gradually increases and the late stage of deceleration when the engine brake is too effective, the required small region α3 is selected, and the central phase of the intake operating angle is further advanced while increasing the throttle opening. Thus, it is possible to reduce the pumping loss without causing an excessive decrease in the intake air amount while maintaining the operating angle near the minimum value. As described above, during the vehicle deceleration, the pumping loss is smoothly reduced by appropriately controlling the throttle 27, the lift / operating angle variable mechanism 1 and the phase variable mechanism 21 according to the situation, thereby reducing the internal combustion engine. A smooth and comfortable deceleration feeling can be obtained without temporarily increasing the deceleration acceleration. In addition, there is no sudden change in the intake air amount during vehicle deceleration accompanied by fuel cut, and stable combustibility that does not cause misfire etc. when the next fuel cut is released (when fuel supply is resumed). Obtainable.

  Next, the flow of deceleration control according to the second embodiment of the present invention will be described with reference to FIGS. In the second embodiment, instead of the deceleration acceleration request value TG in the first embodiment, an estimated deceleration acceleration value RG is estimated and calculated. Based on this estimated value RG, the throttle 27, lift and operating angle are calculated. The three mechanisms of the variable mechanism 1 and the phase variable mechanism 21 are appropriately controlled. FIG. 6 is a flowchart showing the flow of deceleration control of the internal combustion engine according to the second embodiment. This routine is repeatedly executed by the engine control unit 19 every predetermined period.

  In step 11, as in step 1 above, it is determined whether the vehicle is decelerating with a fuel cut. If the deceleration determination is negative, the routine proceeds to step 12 where the operation of the throttle 27 is controlled by another routine (not shown) and the operations of the variable valve mechanisms 1 and 21 are controlled toward the target valve timing. .

If it is determined that the vehicle is decelerating, the routine proceeds to step 13 where an estimated value RG that is the actual value of the deceleration acceleration (deceleration G) corresponding to the deceleration torque of the internal combustion engine is calculated and estimated. Specifically, the estimated value RG is obtained by multiplying a predetermined coefficient, the engine speed, and the gear ratio of the continuously variable transmission 31. The above coefficient may be a fixed value or may be searched for a map from water temperature, oil temperature, or the like.

  In step 14, it is determined whether this estimated value RG is smaller than a predetermined lower limit target value TGG2. In step 15, it is determined whether the estimated value RG is smaller than a predetermined upper limit target value TGG1. These target values TGG1 and TGG2 are obtained by searching the control map of FIG. 7 set and stored in advance from the vehicle speed. As shown in FIG. 7, the upper limit target value TGG1 corresponds to the upper limit value of the deceleration acceleration target region β2, and is set to a value larger than the lower limit target value TGG2. The lower limit target value TGG2 corresponds to the lower limit value of the deceleration acceleration target region β2. These target values TGG1 and TGG2 are fixed values when the vehicle speed is equal to or less than a predetermined value V0, and increase in proportion to the vehicle speed when the vehicle speed exceeds V0.

  When the estimated value RG is smaller than the lower limit target value TGG2, the process proceeds to step 16 where the opening of the throttle 27 is decreased, the operating angle of the intake valve is increased, compared to the target area β2. The center phase of the intake valve operating angle is retarded. Specifically, as shown in FIG. 3, the throttle 27 is fully closed, the intake valve opening timing IVO is advanced from the top dead center TDC, and the closing timing IVC is retarded from the bottom dead center BDC. Then, the operating angle and the center phase are set. Thereby, a pumping loss can be enlarged and sufficient deceleration acceleration can be ensured.

  In the target region β2 in which the estimated value RG is equal to or higher than the lower limit target value TGG2 and lower than the upper limit target value TGG1, the process proceeds to Step 17. In the target region β2, the operating angle of the intake valve is decreased while mainly increasing the throttle opening as compared with the estimated value under-range region β1. Further, the central phase is slightly advanced. Specifically, as shown in FIG. 3, the throttle opening is set to a predetermined small opening, the intake valve opening timing is near the top dead center TDC, and the intake valve closing timing is lower than the bottom dead center BDC. The operating angle and the center phase are set so that the angle is greatly advanced. Typically, the operating angle is the minimum value. As a result, the pumping loss can be suppressed and the suction negative pressure can be reduced as compared with the estimated value under-range region β1.

  In the estimated value excessive region β3 where the estimated value RG is larger than the upper limit target value TGG1, the process proceeds to Step 18. In the estimated value excessive region β3, the central phase is advanced while mainly increasing the throttle opening as compared with the target region β2. Specifically, as shown in FIG. 3, the throttle opening is set to a predetermined medium opening, the closing timing of the intake valve is advanced from the top dead center TDC, and the closing timing is further from the bottom dead center. The operating angle and the center phase are set so that the angle is greatly advanced. The pumping loss can be further reduced by reducing the pumping loss by increasing the throttle opening and by reducing the pumping loss by shortening the opening period of the intake valve by reducing the operating angle. In this embodiment, when the intake valve closing timing IVC is advanced, the center phase of the intake valve operating angle is advanced by the phase variable mechanism 21, so that by expanding the overlap region with the exhaust valve, Compared with the target region β2, the pumping loss can be further reduced without changing the operating angle substantially to the lower side.

According to the second embodiment, as shown in FIG. 3, during the deceleration of the vehicle, the estimated value RG of the deceleration acceleration is typically reduced under the range β1 → the target range β2 → excessively mainly according to the decrease in the vehicle speed. The region β3 is shifted in this order. As a result, at the initial stage of deceleration where the vehicle speed is still high, the estimated value under-range region β1 is selected, the throttle is closed, the intake operating angle is increased, the center phase is delayed, and the pumping loss is positively increased. It is possible to ensure a moderate deceleration acceleration. Thereafter, when the vehicle decelerates and enters the middle stage of deceleration, the target region β2 is selected, and the operating angle of the intake valve is decreased while mainly opening the throttle 27. Thereby, it is possible to reduce the suction negative pressure while favorably reducing the pumping loss. In addition, the estimated value excess region β3 is selected in the late stage of deceleration where the vehicle deceleration further increases and the gear ratio gradually increases and the engine brake is too effective. In this late stage of deceleration, pumping is performed without causing an excessive decrease in the intake air amount by advancing the central phase of the intake operating angle while increasing the throttle opening while keeping the operating angle at the minimum value. Loss can be reduced. As described above, during the vehicle deceleration, the pumping loss is smoothly reduced by appropriately controlling the throttle 27, the lift / operating angle variable mechanism 1 and the phase variable mechanism 21 according to the situation, thereby reducing the internal combustion engine. A smooth and comfortable deceleration feeling can be obtained without temporarily increasing the deceleration acceleration. In addition, it is possible to obtain a stable combustibility that does not cause misfire or the like when the next fuel cut is released (when the fuel supply is resumed) without causing a sudden change in the intake air amount during vehicle deceleration accompanied by a fuel cut. it can.

  The characteristic technical ideas that can be grasped from the above description are listed below.

  (1) An operating angle variable mechanism 1 that makes the operating angle of the intake valve 11 variable, a phase variable mechanism 21 that makes the center phase of the operating angle of the intake valve 11 variable with respect to the crank angle, and an intake passage 25 are opened and closed. Calculated by the throttle 27, the required / estimated value calculating means (step 2 and step 13) for calculating the required value TG or estimated value RG of the deceleration of the internal combustion engine during vehicle deceleration, and the required / estimated value calculating means. In accordance with the required value TG or the estimated value RG, there is provided cooperative control means for cooperatively controlling the opening degree of the throttle 27, the operating angle of the intake valve 11, and the closing timing of the intake valve 11.

  (2) The operating angle variable mechanism 1 that makes the operating angle of the intake valve 11 variable, the phase variable mechanism 21 that makes the center phase of the operating angle of the intake valve 11 variable with respect to the crank angle, and the intake passage 25 are opened and closed. In the required large area α1, the required value calculating means (step 2) for calculating the required value TG of the deceleration of the internal combustion engine during vehicle deceleration, and the required value TG larger than the predetermined required area α2 The first deceleration control means (step 4) for reducing the opening degree of the throttle 27 and increasing the operating angle of the intake valve 11 as compared with the requested middle area α2, and the requested value RG is the requested middle area. The required small area α3 smaller than α2 includes second deceleration control means for increasing the opening degree of the throttle 27 and advancing the closing timing of the intake valve as compared with the required area α2.

  (3) The second deceleration control means advances the closing timing of the intake valve by advancing the center phase (step 6).

  (4) The required value calculation means calculates the required value RG based on the vehicle speed and the engine speed (FIG. 5).

  (5) The operating angle variable mechanism 1 that makes the operating angle of the intake valve 11 variable, the phase variable mechanism 21 that makes the center phase of the operating angle of the intake valve 11 variable with respect to the crank angle, and the intake passage 25 are opened and closed. In the throttle 27, the estimated value calculating means (step 13) for calculating the estimated value RG of the deceleration of the internal combustion engine during vehicle deceleration, and the estimated value under-region β1 where the estimated value RG is smaller than the predetermined target region β2. The first deceleration control means (step 16) for reducing the opening of the throttle 27 and increasing the operating angle of the intake valve 11 as compared with the target region β2, and the estimated value RG is larger than the target region. The estimated value excessive region β3 includes second deceleration control means for increasing the opening degree of the throttle 27 and advancing the closing timing of the intake valve as compared with the target region β2.

  (6) The second deceleration control means advances the closing timing of the intake valve by advancing the center phase (step 17).

  (7) The estimated value calculating means calculates the estimated value RG based on the engine speed and the transmission gear ratio (step 13).

  (8) The operating angle variable mechanism 1 includes a control shaft 12, an actuator for changing / holding the rotational position of the control shaft 12, a control eccentric shaft portion 18 provided eccentric to the control shaft 12, and the control eccentricity. A rocker arm 6 slidably fitted to the shaft 18, a swing cam 9 slidably fitted to the drive shaft 2 that rotates in conjunction with the crankshaft, and opens and closes the intake valve 11, and the drive shaft 2, a drive eccentric shaft portion 3 eccentrically provided at 2, a first link 4 linking the drive eccentric shaft portion 3 and one end of the rocker arm 6, the other end of the rocker arm 6, and the tip of the swing cam 9. And a second link 8 that is linked.

  (9) An operating angle variable mechanism 1 that makes the operating angle of the intake valve 11 variable, a phase variable mechanism 21 that makes the central phase of the operating angle of the intake valve 11 relative to the crank angle, and a throttle 27 that opens and closes the intake passage 25. And having. When the deceleration state of the vehicle is detected, first, the opening degree of the throttle 27 is reduced, the operating angle of the intake valve 11 is increased, and the central phase is retarded (steps 4 and 16). And the operating angle of the intake valve 11 is decreased (steps 5 and 17). Next, the opening of the throttle 27 is increased and the closing timing of the intake valve is advanced (step). 6, Step 18).

  (10) In the above (9), more specifically, the closing timing of the intake valve is advanced by advancing the central phase (steps 6 and 18).

  As described above, the present invention has been described based on the specific embodiments. However, the present invention is not limited to the above-described embodiments, and includes various modifications and changes without departing from the spirit of the present invention. . For example, in the first and second embodiments described above, the case where the control during deceleration is simply switched to the three stages α1, α2, α3 (β1, β2, β3) has been described. You may make it switch more than a step or substantially steplessly or continuously. In this case, a smoother feeling of deceleration can be obtained.

The perspective view which shows an example of the lift and operating angle variable mechanism and phase variable mechanism which concern on this invention. 1 is a system configuration diagram schematically showing an example of an intake system of an internal combustion engine to which a deceleration control device according to the present invention is applied. Time chart during vehicle deceleration. The flowchart which shows the flow of the deceleration control of the internal combustion engine which concerns on 1st Example of this invention. The control map used with the flowchart of FIG. The flowchart which shows the flow of the deceleration control of the internal combustion engine which concerns on 2nd Example of this invention. 7 is a control map used in the flowchart of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Lift / working angle variable mechanism 2 ... Drive shaft 3 ... Drive eccentric shaft part 4 ... 1st link 6 ... Rocker arm 8 ... 2nd link 9 ... Swing cam 12 ... Control shaft 18 ... Control eccentric shaft part 19 ... Engine control Unit 21 ... Variable phase mechanism 25 ... Intake passage 27 ... Throttle

Claims (8)

An operating angle variable mechanism that makes the operating angle of the intake valve variable,
A phase variable mechanism that makes the center phase variable with respect to the crank angle of the operating angle of the intake valve;
An electronically controlled throttle that opens and closes the intake passage;
Coordinated control for controlling the throttle, the operating angle, and the closing timing of the intake valve by controlling the operation of the throttle, the operating angle variable mechanism, and the phase variable mechanism according to a decrease in the vehicle speed during vehicle deceleration. and it means, possess,
The cooperative control means is
A first region on the high vehicle speed side, which is preset based on the vehicle speed and the engine rotational speed and has a large required value of deceleration acceleration corresponding to the deceleration torque required for the internal combustion engine, and the deceleration above the first region. A second area where the required value of acceleration is small, and a third area where the required value of deceleration acceleration is smaller than that of the second area,
The first region and the second region on the lower vehicle speed side than the first region are divided by a first boundary characteristic in which the engine rotational speed decreases as the vehicle speed decreases, and the second region The region and the third region on the vehicle speed side lower than the second region are divided by a second boundary characteristic in which the engine speed decreases as the vehicle speed decreases,
In the first region, the throttle opening is decreased and the intake valve operating angle is increased.
When the vehicle shifts from the first region to the second region in response to a decrease in the vehicle speed, the throttle opening is increased and the intake valve operating angle is decreased compared to the first region. And
When the vehicle shifts from the second region to the third region in response to a decrease in vehicle speed during deceleration of the vehicle, the throttle opening is increased and the closing timing of the intake valve is decreased as compared with the second region. A deceleration control device for an internal combustion engine that is advanced before the dead center. An operating angle variable mechanism that makes the operating angle of the intake valve variable,
A phase variable mechanism that makes the center phase variable with respect to the crank angle of the operating angle of the intake valve;
An electronically controlled throttle that opens and closes the intake passage;
Coordinated control for controlling the throttle, the operating angle, and the closing timing of the intake valve by controlling the operation of the throttle, the operating angle variable mechanism, and the phase variable mechanism according to a decrease in the vehicle speed during vehicle deceleration. Means, and
The cooperative control means is
It has first to third regions preset for deceleration acceleration and vehicle speed obtained by multiplying the engine speed and gear ratio, and the first region on the high vehicle speed side and lower than this first region. The second area on the vehicle speed side is classified by a first boundary characteristic in which the deceleration acceleration decreases as the vehicle speed decreases at least when the vehicle speed is greater than a predetermined value. The third region on the lower vehicle speed side than the region 2 is classified by a second boundary characteristic in which the deceleration acceleration decreases as the vehicle speed decreases, at least when the vehicle speed is greater than a predetermined value.
In the first region, the throttle opening is decreased and the intake valve operating angle is increased.
When the vehicle shifts from the first region to the second region in response to a decrease in the vehicle speed, the throttle opening is increased and the intake valve operating angle is decreased compared to the first region. And
When the vehicle shifts from the second region to the third region in response to a decrease in vehicle speed during deceleration of the vehicle, the throttle opening is increased and the closing timing of the intake valve is decreased as compared with the second region. A deceleration control device for an internal combustion engine that is advanced before the dead center. When the cooperative control means shifts from the second region to the third region in response to a decrease in vehicle speed during the vehicle deceleration , the overlap region with the exhaust valve is expanded as compared with the second region. The deceleration control device for an internal combustion engine according to claim 1 or 2 , wherein the closing timing of the intake valve is advanced before bottom dead center by advancing the center phase. The internal combustion engine speed reduction control device according to any one of claims 1 to 3, wherein the speed ratio of the continuously variable transmission is controlled to increase when the vehicle speed is reduced . 2. In the first region, the throttle is fully closed, the opening timing of the intake valve is advanced before top dead center, and the closing timing of the intake valve is retarded after bottom dead center. The deceleration control device according to any one of to 4 . The operating angle variable mechanism includes a control shaft, an actuator for changing / holding the rotational position of the control shaft, a control eccentric shaft portion eccentrically provided on the control shaft, and swingable on the control eccentric shaft portion. A rocker arm to be fitted, a swing cam that is swingably fitted to a drive shaft that rotates in conjunction with a crankshaft, and that opens and closes an intake valve; a drive eccentric shaft portion that is provided eccentric to the drive shaft; a first link that links the end of the drive eccentric shaft portion and the rocker arm, according to any one of claims 1 to 5 having, a second link that links the tip of the other end and the swing cam of the rocker arm The internal combustion engine deceleration control apparatus. An internal combustion engine having an operating angle variable mechanism that makes the operating angle of the intake valve variable, a phase variable mechanism that makes the central phase of the operating angle of the intake valve relative to the crank angle variable, and an electronically controlled throttle that opens and closes the intake passage In the engine deceleration control method,
A first region on the high vehicle speed side, which is preset based on the vehicle speed and the engine rotational speed and has a large required value of deceleration acceleration corresponding to the deceleration torque required for the internal combustion engine, and the deceleration above the first region. A second area where the required value of acceleration is small, and a third area where the required value of deceleration acceleration is smaller than that of the second area,
The first region and the second region on the lower vehicle speed side than the first region are divided by a first boundary characteristic in which the engine rotational speed decreases as the vehicle speed decreases, and the second region The region and the third region on the vehicle speed side lower than the second region are divided by a second boundary characteristic in which the engine speed decreases as the vehicle speed decreases,
When detecting the deceleration state of the vehicle, first, in the first region in the early stage of deceleration, the throttle opening is reduced, the intake valve operating angle is increased, and the center phase is retarded.
Next, when the vehicle speed decreases and the shift from the first region to the second region, the throttle opening is increased and the intake valve operating angle is decreased.
Next, as the vehicle speed decreases, when the second region is shifted to the third region, the throttle opening is increased and the closing timing of the intake valve is advanced before the bottom dead center. A method for controlling deceleration of an internal combustion engine. When shifting from the second region to the third region, the intake valve is closed by advancing the central phase so as to expand the overlap region with the exhaust valve as compared to the second region. The method for controlling deceleration of an internal combustion engine according to claim 7 , wherein the timing is advanced before bottom dead center.

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