JP3089869B2 - Automotive engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automobile engine and, more particularly, to a vehicle engine having a structure capable of suspending operation of a valve device for intake and exhaust in a selected one of a plurality of cylinders. Automobile engine.

[0002]

2. Description of the Related Art During operation of an internal combustion engine, a valve stop mechanism capable of stopping intake and fuel supply to some cylinders and performing cylinder deactivated operation in order to timely reduce output and reduce fuel consumption. 2. Description of the Related Art An internal combustion engine provided with an engine is known. Control means for controlling a valve stop mechanism of this kind of internal combustion engine stops the opening / closing operation of the intake / exhaust valves of the cylinders and stops fuel supply to the cylinders when the engine enters a set operation area based on various operation information. When the supply is stopped and the vehicle leaves the set operation range, the opening / closing operation of the intake / exhaust valves of the cylinders in the closed cylinder is returned to a normal state, and the supply of fuel to the cylinder in the closed cylinder is restarted.

[0003] In the above-described cylinder stop state, for example, in the case of a four-cylinder engine, the first cylinder having the same piston stroke is used to reduce fuel consumption. The setting is performed based on a map determined by determining the engine speed and the volumetric efficiency of air in the cylinder corresponding to the load information.

[0004]

However, in general, it is necessary to maintain the combustion while keeping the rotation on the engine side low during idling operation of the engine, including the engine using such a cylinder deactivation system. is there.
Therefore, for example, when the cylinder-stop mode is set for the purpose of giving priority to fuel efficiency during the idling operation, for example, 30
On the other hand, as shown in FIG. 17, the rotational restoring force in the closed cylinder state (shown by a broken line) compared to the full cylinder state shown by a solid line, as shown in FIG. Since the return torque is weak, there is a possibility that the idle rotation becomes unstable due to disturbance. This is because when the closed cylinder state (two cylinders) is set as compared with the case of all cylinders (four cylinders), the amount of cylinders used in the combustion stroke is reduced, and the intake inertia effect is reduced. This is because the output cannot be improved due to the decrease in volumetric efficiency.

[0005] Therefore, when the cylinder-stop state is set during the idling operation, the idle rotation becomes unstable with respect to an increase in load when the air conditioner is operated or when the power steering mechanism is operated, for example. Alternatively, the engine may stop.
In view of the above, an object of the present invention is to take into account the above-described problems in an automobile engine in which a cylinder deactivation system can be set. In particular, when the cylinder deactivation state is set during idling operation, a situation occurs in which idle rotation is reduced. In such a case, an object of the present invention is to provide an automobile engine having a structure capable of prohibiting the setting of the cylinder rest state and preventing the occurrence of rotational irregularities and engine stalls.

Further, in an engine using such a cylinder rest system, as a structure for switching the state between all cylinders, for example, a movement of a plunger which can be protruded and retracted in a rocker shaft by a hydraulic drive mechanism is set. In the case of the structure described above, a situation may occur in which the plunger is returned to the original state immediately after setting the all-cylinder state or the closed-cylinder state by moving the plunger to one side. That is, in the map for determining the all-cylinder / closed-cylinder state, when the vehicle is operated in a state in which the conditions are alternately changed at a boundary between the all-cylinder state and the closed-cylinder state, The all-cylinder state and the closed-cylinder state are frequently switched.
Therefore, in such a case, the movement of the plunger must be instantaneously switched, thereby, for example, when the plunger attempts to engage with the engaged portion on the rocker shaft side, the engagement is released. If the plunger is released or, conversely, is returned to the engaged state while trying to move to the disengaged state, the position of the plunger remains unstable, or the plunger is covered by the movement switching. There is a possibility that the collision between the components with the engaging portion may occur and the valve mechanism may be damaged.

Therefore, another object of the present invention is to provide a valve for setting the cylinder-stopping system when the cylinder-stopping state can be frequently switched in view of the above-mentioned problem in an automobile engine capable of setting the cylinder-stopping system. An object of the present invention is to provide an automobile engine having a structure that can prevent damage to the configuration. Furthermore, in the case of general engines, including engines using such a cylinder deactivation system,
For example, as in the case where an air conditioner is operating, a so-called idle bead control (ISC) mechanism for increasing the intake air amount in accordance with an increase in the load of the engine is provided to reduce the engine output. In some cases, it is possible to prevent the rotation from becoming unstable or causing an engine stall when the idling rotation decreases.

When the idle speed control mechanism is provided in an engine using a cylinder deactivation system, the volumetric efficiency of air increases due to an increase in the amount of air when the air conditioner is operated. In some cases, the cylinder is switched from the rest cylinder state to the all cylinder state. Therefore, even if the fuel efficiency is reduced by running in the cylinder-stopped state, the cylinder-stopped state is set to improve the fuel efficiency by switching the operation mode to the full cylinder state by increasing the volumetric efficiency. The benefits will be lost. In view of the above, another object of the present invention is to solve the above-described problem in an automobile engine that can set the cylinder-stop system.
Equipped with a structure that prevents the setting range of the cylinder-stop state from being narrowed in response to the operation of the air conditioner during running and ensures improved fuel efficiency by setting the cylinder-stop state. The object is to obtain an automobile engine.

[0009]

[0010]

[0011]

[0012]

SUMMARY OF THE INVENTION In order to achieve the above-mentioned object, the present invention relates to an engine for detecting the engine speed in an automobile engine in which some cylinders are deactivated according to the operating state of the engine. a sensor, a boost pressure sensor for outputting a boost pressure information for detecting an intake pipe negative pressure, different
Engine speed and boost with a set rest cylinder range
Multiple judgment maps based on pressure information and engine load
The above-mentioned judgment is performed according to the load sensor
And a control device for switching the constant map . Further, according to the present invention, the load sensor is an idle switch.
The control device has an output from the load sensor.
If the idle state is detected, the lower engine limit
And selecting a map having a low rotational speed .

Further, the present invention is characterized in that the load sensor detects the operation or non-operation of the air conditioner. Further, the present invention is characterized in that the transition to the cylinder-stop operation is prohibited for a predetermined time after the transition to the all-cylinder operation even if the cylinder-stop transition condition is satisfied.

[0014]

As described above, according to the present invention, the engine load is detected by the load sensor, and the control device switches the determination map according to the output of the load sensor. Is selected, and if there is a disturbance that lowers the engine speed on that determination map, the setting of the cylinder closed state is prohibited. Further, according to the present invention, the control device detects the idle state from the output of the idle switch as a load sensor. The switching is performed, and the cylinder can be switched immediately.

Further, according to the present invention, the load sensor detects the operation or non-operation of the air conditioner, and when the air conditioner is operated during traveling, the air conditioner is not operated. In addition to the map for determining the number of cylinders and cylinders based on the engine speed and the volumetric efficiency of air used at times, all cylinders and cylinders whose determination area is changed based on the volumetric efficiency of air increased by the operation of the air conditioner Is set based on the determination map of (1). In addition, the determination map for all cylinders and closed cylinders in which the determination area has been changed based on the volumetric efficiency of air increased by the operation of the air conditioner, during idle operation,
At a rotational speed equal to or lower than the rotational speed at which the idle rotation becomes unstable, the all-cylinder state is set.

Further, according to the present invention, the shift to the cylinder-stop operation is prohibited for a predetermined time after the shift to the all-cylinder operation even if the cylinder-stop-shift condition is satisfied, that is, the hydraulic pressure once switched Even if the switching of the operation of the solenoid valve on the control device side is continued for a predetermined time, and the switching of the all cylinders / rest cylinder state is set again during this time, the switching of the operation by the solenoid valve for the switching is prohibited. Therefore, frequent switching of the operation by the solenoid valve is restricted.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The engine control apparatus according to the present invention shown in FIG. 1 is mounted on an in-line four-cylinder engine (hereinafter simply referred to as engine E) having an operation mode switching mechanism.

The intake passage 1 of the engine E includes an intake branch pipe 6, a surge tank 9 connected thereto, an intake pipe 7 integrated with the tank, and an air cleaner (not shown). The intake pipe 7 pivotally supports the throttle valve 2 therein, and the shaft 201 of the throttle valve 2 is connected to the throttle lever 3 outside the intake passage 1. The throttle valve 2 is connected to the throttle lever 3 via a throttle lever 3 linked to an accelerator pedal (not shown).
The throttle valve 2 is closed so as to rotate in a counterclockwise direction in the figure, and the throttle valve 2 is closed by a return spring (not shown) for urging the throttle valve 2 in a closing direction when the absorption force of the accelerator cable is reduced. It has become. The throttle valve 2 is provided with a throttle disclosing sensor 8 for outputting opening degree information of the throttle valve 2 and an idle switch 27 which is turned on when the throttle valve 2 is at the fully closed position.

On the other hand, an intake bypass passage 101 bypassing the throttle valve 2 is provided with an idle speed control (ISC) valve 4 for idling control.
1 and is driven by a stepper motor 5 as an actuator. The first idle air valve 16 automatically performs warm-up correction during idling according to the cooling water temperature. In addition, ISC valve 4
Is mounted with an ISC position sensor 28 which emits opening position information corresponding to the opening of the valve 4.

Further, the intake passage 1 is provided with an intake air temperature sensor 14 for outputting information on intake air temperature Ta, and a cylinder block (not shown) is provided with a water temperature sensor 11 for detecting a cooling water temperature as a warm-up temperature of the engine and knock information. A knock sensor 21 for outputting is provided. The ignition coil (not shown) is provided with a rotation speed sensor 12 for detecting the engine rotation speed by an ignition pulse. The electric circuit (not shown) is provided with a battery sensor 34 for detecting a battery voltage VB. Is equipped with a boost pressure sensor 10 that outputs information on the intake pipe Pb. Further, a crankshaft (not shown) of the engine E is provided with a crank angle sensor 33 for outputting crank angle information.

An air conditioner switch 29 provided in the vehicle for detecting on / off of the air conditioner, and a power steering switch 32 for detecting the operation of the power steering are mounted near a power steering pump (not shown). In the cylinder head 13 of the engine E, an intake path and an exhaust path that can communicate with each cylinder are formed, respectively, and each flow path is opened and closed by an intake valve and an exhaust valve (not shown). The configuration of the valve train mounted on the cylinder head 13 will be described later in detail, but the configuration of the valve train is configured to be able to operate in low-speed mode and high-speed mode, and at the appropriate time, as a constantly operating cylinder. Of the first cylinder (# 1) and the fourth cylinder (# 4) as cylinders other than the second cylinder (# 2) and the third cylinder (# 3) are stopped in the cylinder rest mode. It is possible to drive. That is, a low-speed switching mechanism K1 and high-speed switching mechanisms K2a and K2b are mounted on this valve train.
1, K2a and K2b are configured so that the engagement and disengagement of the rocker arm and the rocker shaft are switched by a hydraulic cylinder via an engagement pin, so that the engagement and disengagement of the elevation cam and the rocker arm can be selectively performed.

The hydraulic circuit 22 supplies a first solenoid valve 2 to the cylinder-stop switching mechanism K1 as an operation mode switching mechanism.
6 is supplied through the high-speed switching mechanism K2a,
Pressure oil is supplied to K2b from the hydraulic circuit 30 via the second solenoid valve 31. Here, the first solenoid valve 26 and the second solenoid valve 31 which are three-way valves during the low speed mode operation by the low speed cam.
Are both off, the first solenoid valve 26 and the second solenoid valve 31 are both on during the high-speed mode operation by the high-speed cam, and only the first solenoid valve 26 is on during the cylinder-stop mode operation.
The second solenoid valve 31 is off. These two solenoid valves 26, 3
1 is an engine control unit (ECU) described later
15 is driven and controlled. Further, an injector 17 for injecting fuel into each cylinder is mounted on the cylinder head 13 shown in FIG. 1, and each injector receives the fuel, which has been adjusted at a constant pressure by the fuel pressure adjusting means 18, by a fuel supply source 19. , The ECU 15.

Further, the cylinder head 13 shown in FIG. 1 is provided with an ignition plug 23 for each cylinder. In particular, both plugs 23 of the always operating cylinders # 2 and # 3 are connected together to form a single ignition drive circuit. The plugs 23 of the cylinders # 1 and # 4 are connected together and connected to the igniter 25. Both igniters 24 and 25 are ECU1
5 is connected. Next, the structure of the valve train according to the present invention will be described in detail with reference to FIGS. As shown in FIGS. 4 to 6 and 12, the cylinder head 13 is provided with a pair of intake camshafts 42 and exhaust camshafts 43 which are parallel to each other along the longitudinal direction. A low-speed cam 44 having a small lift amount and a high-speed cam 45 having a large lift amount are formed integrally with each cylinder. The pair of camshafts 42, 4
3 are bolts 48, 49 sandwiched between the upper portion of the camshaft housing 46 and the plurality of cam caps 47.
By being fixed to the upper part of the cylinder head 13, it is rotatably supported by the cylinder head 13.

Further, the cylinder head 13 is parallel to each other along its longitudinal direction, and will be described in detail later.
A pair of intake rocker shaft portions 51 and an exhaust rocker shaft portion 52 that are parallel to the pair of cam shafts 42 and 43 are provided for each cylinder. The pair of rocker shaft portions 51 and 52 are fixed to the lower portion of the cylinder head 13 by bolts 49 and 54 while being sandwiched by the lower portion of the camshaft housing 46 and the plurality of rocker shaft caps 53, so that the cylinder head 13 13 is rotatably supported. Note that a cylinder head cover 55 is fixed to an upper portion of the cylinder head 13.

Each of the rocker shafts 51 and 52 has a valve operating device that can be switched between a valve opening / closing timing for high-speed operation and a valve opening / closing timing for low-speed operation, a valve opening / closing timing for high-speed operation, and a valve for low-speed operation. A valve train that can be switched to open / close timing and can be closed during low load operation is mounted. That is, as shown in FIG. 12, the valve gear 6 of the upper and lower two cylinders of the four cylinders
1 has a cylinder-stop mechanism, and the central two-cylinder valve train 62 does not have a cylinder-stop mechanism.

Here, the valve train 61 with a cylinder rest mechanism will be described. As shown in FIG. 7, first, the exhaust rocker shaft portion 52 will be described in detail. An exhaust arm portion 52a is formed by extending integrally from a substantially central portion of the exhaust rocker shaft portion 52 at right angles. It is formed by the mold lever 63. The intake rocker shaft 5
1 also has a T-shaped lever 63 integrally formed on an exhaust rocker shaft and an exhaust arm, and has a similar shape. The exhaust rocker shaft section 52 has a substantially T
A low-speed rocker arm 64 and a high-speed rocker arm 65 are mounted as sub rocker arms on both sides of a T-shaped lever 63 having a V-shape. Exhaust arm 52
The base end of a is manufactured integrally with the rocker shaft portion 52,
An adjusting screw 66 is attached to the swinging end by an adjusting nut 67, and a lower end of the adjusting screw 66 is in contact with an upper end of an exhaust valve 80 described later.

On the other hand, the low-speed rocker arm 64 has its base end pivotally mounted on the rocker shaft 52 and is rotatably supported, and has a roller bearing 68 attached to its swinging end. The cam 44 can be engaged. Similarly, the base end of the high-speed rocker arm 65 is pivotally connected to the rocker shaft 52 and is rotatably supported. A roller bearing 69 is attached to the swinging end of the rocker arm 65.
9 can be engaged with a high-speed cam 45.

Further, as shown in FIG. 6, the low-speed rocker arm 64 and the high-speed rocker arm 65 are respectively provided with arm portions 70, 71 on the opposite side to the swinging ends where the roller bearings 68, 69 are mounted. Are formed integrally,
The arm portions 70 and 71 have arm springs 72 and 7 respectively.
3 is working. The arm springs 72 and 73 are constituted by a cylinder 74 fixed to the cam cap 47, a plunger 75, and a compression spring. The tip of the plunger 75 presses the arm portions 70, 71, and the rocker arms 64, 65 shown on the left side in FIG.
5 are urged in the counterclockwise direction.

Therefore, usually, the low speed rocker arm 64 is used.
And the high-speed rocker arm 65 is an arm spring 7
The roller bearings 68 and 69 are in contact with the outer peripheral surfaces of the low speed cam 44 and the high speed cam 45 of the camshaft 43 by the gears 2 and 73. When the camshaft 43 rotates, the cams 44 and 45 act. Thus, the low-speed rocker arm 64 and the high-speed rocker arm 65 can swing.

As shown in FIG. 8, the low-speed rocker arm 64 and the high-speed rocker arm 65 are provided with a switching mechanism K1.
And K2a so as to be able to rotate integrally with the rocker shaft 52. A through-hole 91 is formed in the rocker shaft 52 at a position corresponding to the low-speed rocker arm 64 along the radial direction.
A lock pin 92 is movably mounted on 1 and
It is urged in one direction by a compression spring 94 supported by a spring seat 93. On the other hand, an engagement hole 95 is formed in the low-speed rocker arm 64 at a position corresponding to the through hole 91 of the rocker shaft 52, and a lock pin 92 urged by a compression spring 94 engages with this engagement hole 95. ing. And rocker shaft 5
2 is formed with a hydraulic passage 22a communicating with the through hole 91 along the axial direction, and an oil passage 97 communicating with the hydraulic passage 22a and opening on the side engaging with the engaging hole 95 is formed on the lock pin 92. Are formed.

A through-hole 98 is formed in the rocker shaft 52 at a position corresponding to the high-speed rocker arm 65 along its radial direction, and a lock pin 99 is movably mounted in the through-hole 98. , Compression spring 1
00 in one direction. On the other hand, in the high-speed rocker arm 65, an engagement hole 101 is formed at a position corresponding to the through hole 98 of the rocker shaft 52.
Get out of. A hydraulic passage 30 a communicating with the through hole 98 is formed in the rocker shaft 52 along the axial direction, and the engagement hole 101 of the through hole 98 is formed.
An oil passage 103 communicating with the end on the opposite side is formed.

Normally, as shown in FIG. 10A, the low-speed rocker arm 64 is
When the lock pin 92 urged by 4 is engaged with the engagement hole 95, the lock pin 92 becomes integral with the rocker shaft 52, and can rotate together with the T-shaped lever 63 via the rocker shaft 52. On the other hand, in the high-speed rocker arm 65, the lock pin 99 urged by the compression spring 100 comes out of the engagement hole 101, the engagement with the rocker shaft 52 is released, and the rocker arm 65 rotates integrally with the rocker shaft 52. Not to be. Therefore, the low-speed cam 44 and the high-speed cam 45 swing the low-speed rocker arm 64 and the high-speed rocker arm 65, but only the transmitted driving force of the low-speed rocker arm 64 is transmitted through the rocker shaft 52 to the T-shape. The T-shaped lever 63 is transmitted to the lever 63 so as to swing.

When hydraulic pressure is supplied to the hydraulic passages 22a and 30a of the rocker shaft 52, FIG. 10 (b)
As shown in the figure, in the low-speed rocker arm 64,
The pressure oil flows through the oil passage 97 to the engagement hole 95 side of the through hole 91, and pulls out the lock pin 92 from the engagement hole 95 against the urging force of the compression spring 94. Then, the engagement between the low-speed rocker arm 64 and the rocker shaft 52 is released, so that the low-speed rocker arm 64 does not rotate integrally. On the other hand, in the high-speed rocker arm 65, the pressure oil flows through the oil passage 103 to the opposite side of the through hole 98 from the engagement hole 101, and the lock pin 9.
9 against the urging force of the compression spring 94.
To be engaged. Then, the high-speed rocker arm 65 and the rocker shaft 52 are engaged, and both can rotate integrally. Therefore, the low speed cam 44 and the high speed cam 4
5 swings the low-speed rocker arm 64 and the high-speed rocker arm 65, but only the transmitted driving force of the high-speed rocker arm 65 is transmitted through the rocker shaft 52 to the T.
The T-shaped lever 63 is transmitted to the mold lever 63 and can be swung.

The hydraulic passage 2 of the rocker shaft 52
When the hydraulic pressure is supplied only to 2a, as shown in FIG. 10 (c), in the low-speed rocker arm 64, the pressure oil flows to the engaging hole 95 side of the through hole 91 to engage the lock pin 92. Withdrawing from the hole 95, the engagement between the low-speed rocker arm 64 and the rocker shaft 52 is released, so that the rocker arm 64 does not rotate integrally. On the other hand, in the high-speed rocker arm 65, the lock pin 99 comes out of the engagement hole 101 by the compression spring 100 and the engagement with the rocker shaft 52 is released, and the two do not rotate integrally. Therefore, the low-speed cam 44 and the high-speed cam 45 swing the low-speed rocker arm 64 and the high-speed rocker arm 65, but the driving force is not transmitted to the rocker shaft 52, and the T-shaped lever 63 does not operate. The cylinder can be brought into the closed state.

Further, in the valve train 62 without the cylinder rest mechanism, as shown in FIG. 11, an arm portion 52a extends vertically from a substantially central portion of the exhaust rocker shaft portion 52 so as to be integrally formed with the arm portion 52a. T-shaped lever (L) 1 with a substantially T-shape
A high-speed rocker arm 105 is rotatably mounted on the exhaust rocker shaft 52. And, at the swinging end of the T-shaped lever (L) 104,
The roller bearing 106 is attached and the low speed cam 44 is mounted.
Can be engaged, and an adjustment screw 107 is attached by an adjustment nut 108, and a lower end of the adjustment screw 107 is in contact with an upper end of an exhaust valve 80 described later.

On the other hand, the high-speed rocker arm 105 has its base end pivotally mounted on the rocker shaft 52 and is rotatably supported, and has a roller bearing 109 attached to its swinging end. The cam 45 can be engaged. An arm 110 is formed integrally with the high-speed rocker arm 105 on the side opposite to the swinging end on which the roller bearing 109 is mounted.
Acts to urge the high-speed rocker arm 105 in one direction. Further, the high-speed rocker arm 105 can rotate integrally with the rocker shaft 52 by the switching mechanism K2b. That is, a through-hole 113 is formed in the rocker shaft 52 at a position corresponding to the high-speed rocker arm 105, a lock pin 114 is movably mounted, and is urged and supported by a compression spring 115. On the other hand, high-speed rocker arm 1
An engagement hole 116 is formed in 05, and the lock pin 114 comes out of the engagement hole 116 by a compression spring 115. A hydraulic passage 30 b communicating with the through hole 113 is formed in the rocker shaft 52 along the axial direction, and an oil passage 118 communicating with the end of the through hole 113 on the opposite side to the engagement hole 116 is formed. Is formed.

However, usually, the high-speed rocker arm 1
05 is a lock pin 114 by a compression spring 115.
Has come out of the engagement hole 116 and the rocker shaft 5
The engagement with the locker shaft 2 is released so that the locker shaft 52 does not rotate integrally with the rocker shaft 52. Therefore, the low-speed cam 44 and the high-speed cam 45 swing the T-shaped lever (L) 104 and the high-speed rocker arm 105. The driving force of the low-speed cam 44 is transmitted to the exhaust valve 80, and Can be rocked.
When hydraulic pressure is supplied to the hydraulic passage 30 b of the rocker shaft 52, in the high-speed rocker arm 105, the pressurized oil flows through the oil passage 118 through the engagement hole 1 of the through hole 113.
16 and the lock pin 114 is inserted into the engagement hole 11.
6 is engaged. Then, the high-speed rocker arm 105
And the rocker shaft 52 are engaged with each other, and the rocker shaft 52 can rotate integrally with the rocker shaft 52. Accordingly, the high-speed cam 45 swings the high-speed rocker arm 105, and the driving force is applied to the rocker shaft 52 and the T-shaped lever (L).
The exhaust gas is transmitted to the exhaust valve 80 via 104 so that the exhaust valve 80 can swing.

In the above description of the valve gears 61 and 62, only the exhaust side has been described. However, the intake side has the same structure, and each camshaft is adjusted in accordance with the opening and closing timing of the intake and exhaust valves. Only the forming positions of the cams 44 and 45 in the circumferential direction of the cams 42 and 43 are different. Incidentally, as shown in FIG. 6, the intake valve 97 and the exhaust valve 80 are movably mounted on the cylinder head 13, and the intake port 83 and the exhaust port 84 are closed by valve springs 81 and 82. Therefore, by driving the above-described T-shaped lever 63 (T-shaped lever (L) 104) to press the upper end portions of the intake valve 79 and the exhaust valve 80, the intake port 83 and the exhaust port 84 are opened and closed to open the combustion chamber 85. You can communicate with it.

FIG. 1, FIG. 2, FIG. 9, FIG.
As shown in FIG. 2, a hydraulic control device 86 for operating the switching mechanisms K1, K2a, K2b of the valve operating devices 61, 62 is provided at a rear portion (an upper portion in FIG. 12) of the cylinder head. . The hydraulic control device 86 includes an oil pump 87, an accumulator 88, the above-described second solenoid valve 31, and the above-described first solenoid valve 26. The oil pump 87 and the accumulator 88 are located between the intake camshaft 42 and the exhaust camshaft 44, and both are arranged vertically, and their axial directions are horizontal. That is, the cylinder 121 of the oil pump 87 is horizontally supported on the upper side of the cam cap housing 46 and the cam cap 47 at the rearmost portion of the cylinder head 13 and is urged and supported by the compression spring 122. It is fixed by a bolt 124 via a cover 123. The compression spring 1 is provided in the cylinder 121 of the oil pump 87.
A plunger 126 operates via the pin 25, and the plunger 126 can be driven by an oil pump cam 127 formed integrally with one end of the intake camshaft 42.

A cylinder 128 of the accumulator 88 is horizontally movable below the side of the cam cap housing 46 and the cam cap 47 and is urged and supported by a compression spring 129.
It is fixed by a bolt 124 via 23. The diameter of the cylinder 121 of the oil pump 87 and the diameter of the cylinder 128 of the accumulator 88 are the same and can be shared. Further, the second solenoid valve 31 and the first solenoid valve 26
Is attached to the cylinder head 11.

As shown in FIGS. 1, 2, 3 and 9, the second solenoid valve 31 is directly connected to the main oil pump 120 of the engine through an oil passage 130,
It is connected to a hydraulic passage 30a via a hydraulic circuit 30. The second solenoid valve 31 is connected to an accumulator 88, an oil pump 87, and a main oil pump 120 via an oil passage 131, and is also connected to a hydraulic passage 22a via a hydraulic circuit 22. Furthermore, each solenoid valve 26, 3
1 can be operated by a control signal of the ECU 15.

The switching mechanism K2b of the valve operating device 62 can be operated by the hydraulic control device 86 in the same manner as the valve operating device 61.
The second solenoid valve 31 is connected to the hydraulic passage 30 b via a hydraulic circuit 30. As shown in FIG. 3, a hollow plug tube 135 is provided upright for each cylinder in the cylinder head 13, and an ignition plug 23 is mounted inside each plug tube 135, respectively.
The front end faces each combustion chamber 85. Hereinafter, the operation of the four-cylinder engine of the present embodiment will be described. ECU
Reference numeral 15 detects the operating state of the engine based on the detection results of various sensors, and if the engine is running at a low speed, selects a cam profile suitable for it. In this case, EC
U15 outputs a control signal to the solenoid valves 26 and 31, and closes the solenoid valves 26 and 31. Then, the hydraulic passages 22a, 30
a, 30b is not supplied with pressure oil, and the valve train 61
As shown in FIG. 0 (a), the low-speed rocker arm 64 and the rocker shaft 52 are integrated by the lock pin 92, and the engagement between the high-speed rocker arm 65 and the rocker shaft 52 is released. Therefore, the camshaft 4
When the low-speed cam 44 rotates, the low-speed rocker arm 64 is swung by the low-speed cam 44, and the driving force is transmitted to the T-shaped lever 63 via the rocker shaft 52, and the T-shaped lever 63 is rotated.
The mold lever 63 swings, and the pair of adjusting screws 66 at the swinging ends drive the intake valve 79 and the exhaust valve 80. On the other hand, as shown in FIG.
When the engagement between the high-speed rocker arm 105 and the rocker shaft 52 is released, and the camshafts 42 and 43 rotate, the T-shaped lever (L) 104 swings by the low-speed cam 44, and a pair of adjustments at the swinging ends are performed. The screw 107 drives the intake valve 79 and the exhaust valve 80. Thus, the intake valve 79 and the exhaust valve 80 are driven at the valve opening / closing timing corresponding to the low-speed operation, and the engine is operated at a low speed.

When the ECU 15 detects a high-speed running state of the engine, the ECU 15 outputs a control signal to the solenoid valves 26 and 31 and opens the solenoid valves 26 and 31. Then, pressure oil is supplied to the hydraulic passages 22a, 30a, 30b. When the engine is running at high speed, the valve gear 61 causes the lock pin 92 to move by the pressure oil as shown in FIG. 10 (b).
Is pulled out from the engagement hole 95, and the engagement between the low-speed rocker arm 64 and the rocker shaft 52 is released. Further, the lock pin 99 is engaged with the engagement hole 101, and the high-speed rocker arm 65 and the rocker shaft 52 are integrated. Therefore, the high-speed rocker arm 6 is moved by the high-speed cam 45.
5 swings, and further the T-shaped lever 63 swings to drive the intake valve 79 and the exhaust valve 80. On the other hand, the valve gear 6
In 2, the lock pin 114 is engaged with the engagement hole 116 by the supply pressure oil, so that the high-speed rocker arm 105 and the rocker shaft 52 are integrated. Therefore, the high-speed rocker arm 105 swings by the high-speed cam 45,
The intake valve 79 and the exhaust valve 80 are driven. Thus, the intake valve 79 and the exhaust valve 80 are driven at the valve opening / closing timing corresponding to the high-speed operation, and the engine is operated at a high speed.

The ECU 15 performs setting of the all cylinder state and the closed cylinder state with respect to the opening and closing of the valves according to a map shown in FIG. That is, the first
FIG. 3 is a determination map of the all-cylinder state and the closed-cylinder state based on the volumetric efficiency (Ev) of air determined by the boost pressure and the engine speed (Ne) for the entire operating range of the engine. The range indicated by hatching in the middle indicates the cylinder rest state.

In this map, the boundary between the all-cylinder state and the closed-cylinder state is set on condition that an output corresponding to the load obtained from the engine speed and the volumetric efficiency of the air is obtained. In FIG. 13, the reason why the volumetric efficiency increases instantaneously in the low rotation speed range is that when switching from the full cylinder state to the closed cylinder state, the rotation speed is increased once and the sudden increase in the closed cylinder setting is performed. This is a measure for suppressing a drop in the number of rotations. Further, in the ECU 15, based on the input of the ON signal from the idle switch 27,
Based on the volumetric efficiency of the air due to the engine speed and boost pressure at that time, when setting the cylinder closed state from the map shown in FIG. 13, instead of returning the throttle during deceleration, for example, during idling operation after cranking In the case where the setting of the cylinder rest state is performed, the following processing is performed.

That is, during the idling operation, a disturbance that reduces the idling speed, in other words, an on / off signal from each of the operation switches of the air conditioner and the power steering mechanism that causes a change in the load, causes the operation switches to be turned off. When any one of them is in the operating state or when an abnormal decrease in the engine speed occurs, the setting of the cylinder rest state is prohibited by determining the logical sum of these states. This is because, as described with reference to FIG. 17, the return torque on the engine side is weaker when the cylinder is in the rest state than when the cylinder is in the all cylinder state, and the return gradient is smaller with respect to load fluctuation. Due to the gradual operation, the idle rotation is prevented from becoming unstable or causing a stall before returning to the normal state.

The ECU 15 sets the full cylinder state and the closed cylinder state for valve opening / closing with reference to FIGS.
The processing is executed according to the map shown in FIG.

That is, FIG. 13 is a map for judging the full cylinder state and the closed cylinder state based on the volumetric efficiency (Ev) of the air determined by the boost pressure and the engine speed (Ne). In FIG. 14 and FIG. 14, the range shown by hatching means the cylinder rest state. FIG. 13 is a determination map of the all-cylinder state and the closed-cylinder state in the entire operation range of the engine, and FIG. 14 is a map based on FIG. 13 when the idle switch 27 is turned off. 4 is a determination map of the all-cylinder state and the closed-cylinder state based on a predetermined rotation speed.

In these maps, the boundary between the all-cylinder state and the closed-cylinder state is set on condition that an output corresponding to the load obtained from the engine speed and the volumetric efficiency of the air can be obtained. In FIG. 13, the volumetric efficiency is instantaneously increased in the low rotation speed range.
When switching from the all-cylinder state to the closed cylinder state, this is a measure for temporarily increasing the rotational speed to suppress a sharp drop in the rotational speed when the closed cylinder is set. In this map, the setting condition of the cylinder deactivation state is changed depending on the on / off state of the idle switch 27. Specifically, when the cylinder deactivation state is set, either the on / off state of the idle switch 27 is determined. The engine speed at which the occurrence of vehicle body vibration is remarkable is set in advance, and the result of comparing and determining the current engine speed at the time of cylinder deactivation determines the all cylinder state and the cylinder deactivated state. The range used for setting the cylinder rest state in the map to be switched is switched.

FIG. 13 is a map which is used in the entire operation range of the engine and is used to set the cylinder rest state when the idle switch 27 is turned on.
FIG. 14 is a map for setting the cylinder deactivation state when the idle switch 27 is turned off, and the map is used to set the cylinder deactivation state. Is 6 in the case of FIG.
00 rpm, and in the case of FIG.
It is set to 0 rpm. These maps are not specially provided for each type. When the idle switch 27 is turned off, the predetermined rotational speed at the time when the idle switch 27 is turned off in the cylinder rest state setting range in the map shown in FIG. Switching is performed so as to use only the range as shown in FIG. 14 as a reference.

The operation of the ECU 15 will be described with reference to FIG. In FIG. 15, when the engine speed (Ne) and the volumetric efficiency (Ev) of air due to the boost pressure are input, based on the maps shown in FIGS. Is determined, and a drive signal for obtaining this state is output to the hydraulic control device 86. Then, in the above-described steps, when the operating position in the hydraulic control device 86 is set, it is determined whether or not the cylinder is in a cylinder-stop state.
The off state is determined, and the number of revolutions on the engine side according to each state is set to 600 rpm when the idle switch 27 is on, and 1600 rpm when the idle switch 27 is off. And the fuel injection control is executed in response to this.

On the other hand, when the engine speed at the current stage in the cylinder-stopped state is inputted, the engine speed is compared with the above-mentioned predetermined speed, and when the engine speed is higher than the predetermined speed, the idle switch 27 is turned on / off. The cylinder rest state is set based on the maps shown in FIGS. 13 and 14 according to the flowchart of A or B described later, and if the rotation speed is equal to or less than the predetermined number of revolutions, A drive signal is output to the hydraulic control device 26 so as to switch to the all-cylinder state through the flowchart. According to the present embodiment, the map for setting all cylinders / rest cylinders according to the on / off state of the idle switch 27 can be diverted based on the number of revolutions, so that the memory capacity of the ECU can be increased. You don't have to.

As described above, in the map for determining the all-cylinder / non-cylinder state, the all-cylinder / non-cylinder state can be switched only by determining the on / off state of the idle switch 27. In the case where it is necessary to switch to the all-cylinder state for the purpose of accelerating while in the cylinder-stopped state, the cylinder to be used can be switched immediately, ignoring the response delay that occurs when the boost pressure is detected. For example, responsiveness related to acceleration performance can be improved. FIG. 16 shows a flowchart of A in which cylinder closing is prohibited when the air conditioner or the power steering is on at the time of idling. That is, it is determined whether or not the air conditioner switch 29 has been input, and if the air conditioner switch 29 has not been turned on, it is determined whether or not the power steering switch 32 has been turned on.

When the ON signals of the air conditioner switch 29 and the power steering switch 32 are inputted, a timer for setting a prohibition time for setting the cylinder closed state after the switches 29 and 32 are turned off is set. Then, a plug for prohibiting the setting of the cylinder rest state is set. The prohibition time until the cylinder stop state is set after the above-mentioned operation signal is turned off is set to the cylinder stop state after the idle rotation is stabilized, and the rotation speed at the time of state change becomes unstable. This is to prevent it. On the other hand, when none of the operation switches is turned on, it is determined whether or not the prohibition time set in the above-described step has been fully increased, and the cylinder deactivation prohibition flag is cleared to enable setting of the cylinder deactivation state. To

When the cylinder-stop state prohibition time is fully increased and the cylinder-stop state can be set, the engine rotational speed (Ne) at the current stage is set when the cylinder-stop state is set. It is determined whether or not the rotation speed is equal to or lower than a limit rotation speed at which rotation becomes unstable. The above-described operation switch ON / OFF determination and the comparison of the rotational speed are all for determining whether there is a possibility of causing a rotational malfunction or an engine stall when the cylinder is set in the closed cylinder state. After the end of the determination, it is determined whether or not the cylinder deactivation prohibition flag is set in the determination result. If the flag is set, a command for setting the state of all cylinders is sent to the hydraulic control device according to the flowchart of C described later. 86, and
If the flag has not been set, a command for setting the cylinder rest state is output to the hydraulic control device 86 through the flowchart of C described later.

Further, in the ECU 15, the hydraulic control device 8 based on the operation mode once selected by the map is used.
In setting the positions of the solenoid valves 26 and 31 operating as the hydraulic drive units on the side 6, the solenoid operating as the hydraulic drive unit for switching the next operation mode for a predetermined time after the operation mode is set is set. The operation switching by the solenoid valves 26 and 31 is prohibited so as not to set the positions of the valves 26 and 31. The operation switching prohibition time is set by operating the first solenoid valve 26 in order to obtain the set operation mode. For example, the lock pin 92 on the rocker shaft 52 and the engagement hole 9 on the low speed rocker arm 64 are operated.
In the case where the disengagement state is switched again while switching the disengagement state with the control unit 5, the disengagement switching is prohibited again. Due to the response delay caused by hysteresis at the time of switching the position of the solenoid valve 26,
The disengagement state is maintained in an incomplete state, or
The components are prevented from colliding with each other between the engaging portions. The second solenoid valve 31 is the same as above.

The operation switching prohibition time is set in a map shown in FIG.
It is set based on the engine speed that affects the hydraulic pressure applied to the solenoid valves 26 and 31, and is longer on the low-speed rotation side where the hydraulic pressure decreases, and shortened as it goes on the high-speed rotation side where the hydraulic pressure increases. In other words, on the low-speed rotation side where the response time for engagement / disengagement switching by the solenoid valves 26 and 31 becomes longer, the prohibition time is lengthened in accordance with the length of this response time. It is said that the time is shortened. Further, in the map shown in FIG. 18, two maps are set according to the difference in the direction in which the hydraulic pressure is applied to the solenoid valves 26 and 31.

The application direction of the hydraulic pressure is, for example, an application direction for applying pressure so as to move the lock pin 92 against the pressure of the compression spring 100 which is urging the lock pin 92, and a pressure Lowering the lock pin 92
There is an application direction in which it is moved by the compression spring 100 that is biasing it. In FIG. 18, the case of the former application direction is indicated by a solid line as the ON side, and the latter is the application direction. The case is indicated by a broken line as the off side. Therefore, on the ON side, the prohibition time is lengthened by the time required for the movement of the plunger, and conversely, on the OFF side, the prohibition time is shortened in response to the shorter movement time.

The operation of the ECU 15 relating to the inhibition of the operation of the solenoid valve will be described with reference to the flowchart of FIG. 19, as shown in FIG. That is, when the volumetric efficiency of the air based on the engine speed and the boost pressure is input to the ECU 15, the determination of the all-cylinder / closed-cylinder state is performed from the map shown in FIG. 13 based on the information. The operation mode in each of these states is determined.

Based on the above-mentioned information, it is determined whether or not the condition for switching the operation mode is determined. If the condition for switching the operation mode is satisfied, the time since the previously determined operation mode was set is set. ,
In other words, it is determined whether or not the operation switching prohibition time after setting the operation mode in the map shown in FIG. 18 has reached “0”.

When the operation switching prohibition time has reached “0”, the positions of the solenoid valves 26 and 31 are set so that the operation mode is switched again, and the operation switching prohibition time is set to “0”. If it is not "0", the clock of the operation switching prohibition time is counted down to prepare for the next command. On the other hand, when it is determined that the operation switching prohibition time has reached “0”, the direction of the hydraulic pressure applied by the solenoid valves 26 and 31 is determined, and the direction in the map shown in FIG. The operation switching prohibition time is set respectively, and from this point of time, the clocking for the prohibition time is executed. Further, the ECU 15 performs a twentieth operation for a case where the air conditioner switch 29 is turned on during traveling.
An air conditioner determination map as shown in the figure is set.

That is, this map is an air conditioner determination map. In this map, when the air conditioner switch 29 is turned on, the intake air amount increases in accordance with an increase in the load on the engine side. Let
When the so-called idle speed control is executed, the area for setting the all cylinder / closed cylinder state in the map shown in FIG. 13 is prevented from becoming narrow based on the increase in the air amount. is there. Then, this air conditioner determination map corresponds to the all cylinder / cylinder rest state determination boundary when the air conditioner is not operating, which is indicated by reference sign A in FIG.
As indicated by the reference sign B, the position is set at a position where the all cylinder / cylinder rest state determination boundary is raised in a range commensurate with the increase in volumetric efficiency during operation of the air conditioner to enlarge the region of the cylinder rest state. In FIG. 20, the boundary between all cylinders / cylinder-stopped state determination when the air conditioner is not operating is:
It may be newly set or may be quoted from the determination map shown in FIG.

Therefore, in the air conditioner determination map,
The air volume efficiency is higher than the boundary between all cylinders / rest cylinders when the air conditioner is not operating and the idle rotation does not decrease. Can also set the cylinder rest state. In FIG. 20, the lines indicated by reference symbols C and D mean the running curves when the vertical axis in FIG. 20 is the engine output and the horizontal axis is the vehicle speed. A running curve in the cylinder-stop state according to the air-conditioner determination map is shown, and a running curve indicated by reference symbol D indicates a running curve in the cylinder-stop state according to the normal all-cylinder / cylinder-stop state determination map without using the air-conditioner determination map. I have. As is clear from the comparison of the running curves,
The engine output in the cylinder-stop state set by the air conditioner determination map is higher than the engine output in the cylinder-stop state set by the normal cylinder / rest cylinder state determination map. This means that the effect of improving fuel efficiency by the cylinder-stop state is maintained for a longer time than when set by the cylinder-stop state determination map.

In the air conditioner determination map, when the air conditioner switch 29 is turned on, there is a danger that the rotation during the idling operation becomes unstable or the engine stalls when the load increases due to the operation of the air conditioner. When the rotation speed is equal to or less than the rotation speed, the cylinder rest state is prohibited, and the entire cylinder state is set. Next, when the idle switch is off, the ECU 15 uses the flowchart of B to change the cylinder-stop zone according to the on / off state of the air conditioner switch.
Will be described. It is determined whether the air conditioner switch 29 is turned on as shown in FIG.

In this determination, the air conditioner switch 29
Is in the off state, all cylinders shown in FIG.
When the cylinder-stop state determination map is selected and the air conditioner switch 29 is turned on, the air-conditioner determination map shown in FIG. 20 is selected. A comparison is made between the volume efficiency at the present stage, which is a parameter for determination, and the volume efficiency in each of the above maps, and according to the result, the cylinder rest state or the all cylinder state is determined. Thus, a signal for setting each state is output to the hydraulic control device 86.

Further, the ECU 15 receives the throttle opening signal from the throttle opening sensor 8 and determines whether the vehicle is in an acceleration state by using the result of calculating the rate of change of the throttle opening. When the all cylinder / closed cylinder state is determined from the map, particularly when the cylinder is in the accelerated state when the closed cylinder state is set for improving fuel efficiency, the volume by the boost pressure is determined. The hydraulic control device 86 is driven so as to switch to the all-cylinder state regardless of the efficiency. The operation of the ECU 15 when it is determined that the vehicle is in the acceleration state will be described with reference to the flowchart of FIG.

That is, when the signal from the throttle opening sensor 8 is input, the volumetric efficiency of the air and the engine speed due to the boost pressure are within the region for setting the cylinder closed state in the map shown in FIG. Determine whether or not
If the area corresponds to the area for setting the cylinder rest state, it is determined whether or not the acceleration flag has been cleared. This acceleration flag is set when the rate of change of the throttle opening within a predetermined time is equal to or more than a predetermined value. If this flag is not set, the cylinder is set to a closed state. The signal for driving the hydraulic control device 86 is E
Output from CU15.

Then, when the cylinder-stopped state is set, it is determined whether a predetermined time has elapsed, in the case of this embodiment, 50 ms has elapsed, and if it has elapsed, the throttle opening sensor 8 at this time determines Throttle opening (THN) by the signal of
And the throttle opening (THL) entered before this
And the rate of change (ΔTH) is determined from the difference between
TH) is compared with a predetermined value (A) for determining that the vehicle is accelerating, and it is determined whether or not TH is equal to or more than the predetermined value. As a result of comparing the rate of change (ΔTH) with respect to the predetermined value, when it is determined that the vehicle is accelerating when the speed is equal to or more than the predetermined value, the continuation flag is set and the cylinder is switched from the cylinder-stop state to the all-cylinder state. The ECU 15 outputs a signal for driving the hydraulic control device 86 as described above.

On the other hand, if the acceleration flag is set, the state of all cylinders is set, and it is determined whether or not the acceleration flag is set.
It is determined whether 100 ms has elapsed, and if it has elapsed, the difference between the engine speed (Nen) at this time and the previously input engine speed (NeL) is determined, and the rate of change (ΔNe) in a predetermined time is determined. ) To determine the rate of change (ΔN
It is determined whether or not e) is equal to or greater than a predetermined value (B). If it is equal to or greater than the predetermined value, it is determined that acceleration has been performed, and the acceleration flag is cleared.

[0070]

As described above, according to the present invention, the determination map of all cylinders / cylinders is switched according to the output of the load sensor, that is, all cylinders / cylinders for giving priority to fuel consumption during idling operation. If there is a disturbance that lowers the engine speed on the basis of this judgment map, the setting of the cylinder rest state is prohibited, and the engine rotation becomes unstable or the engine stalls due to an increase in load in the idle state. It can be prevented beforehand.

Accordingly, it is possible to perform cylinder deactivation in as wide a range as possible while preventing instability of idle rotation due to load fluctuation during cylinder deactivation.

Further, according to the present invention, it is possible to switch between the all-cylinder state and the closed cylinder state only by determining the on / off state of the idle switch. If it is necessary to switch to the all cylinders state for the purpose of switching, the response delay that occurs when the boost pressure is detected is ignored, the map is switched from a map with a lower engine speed in the deactivated cylinder range to a higher map, and the cylinder is switched immediately. Thus, for example, it is possible to improve responsiveness related to acceleration performance.

Further, according to the present invention, the determination of the all-cylinder / closed-cylinder state is made based on different maps when the air conditioner is operating and when it is not operating, which leads to an increase in engine load. Since it is possible to set the cylinder-stopped state up to a region where the efficiency is increased, it is possible to continue the operation in the cylinder-stopped state even when the air conditioner is operating. Fuel efficiency can be improved regardless of ON / OFF.

Further, according to the present invention, the solenoid valve on the hydraulic control device, which has been switched once, continues to switch the operation for a predetermined period of time, during which the switching between the all-cylinder / rest-cylinder state is set again. However, since switching of operation by the solenoid valve for switching is prohibited, when the switching of operation by the solenoid valve is performed frequently, response delay due to hysteresis when switching the position of the solenoid valve, It is possible to prevent the hydraulic control device from being set in an odd position, or to prevent a component of the solenoid valve from being damaged such as a spool valve.

[0075]

[0076]

[0077]

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of an automobile engine as one embodiment of the present invention.

FIG. 2 is a sectional view of an essential part (AA in FIG. 3) of a cylinder head showing a valve train of an internal combustion engine according to one embodiment of the present invention.

3 is a cross-sectional view of the center (BB in FIG. 12) of the cylinder head of the automobile engine shown in FIG. 1;

FIG. 4 is a plan view of a valve train with a cylinder stopping mechanism of the automobile engine of FIG. 1;

FIG. 5 is a sectional view taken along line CC of FIG. 4;

FIG. 6 is a sectional view taken along line DD of FIG. 4;

FIG. 7 is an exploded perspective view of the valve train of the automobile engine shown in FIG. 1;

8 is a cross-sectional view illustrating a switching mechanism of the valve train of the automobile engine of FIG.

FIG. 9 is a hydraulic path diagram of the valve train of the automobile engine of FIG. 1;

10A and 10B are explanatory diagrams of the operation of the switching mechanism of the automobile engine in FIG. 1, wherein FIG. 10A illustrates a switching state at a low speed, FIG. 10B illustrates a switching state at a high speed, and FIG. This shows the switching state.

11 is a cross-sectional view of the valve train of the automobile engine of FIG. 1 without a cylinder rest mechanism.

FIG. 12 is a plan view of a cylinder head of the automobile engine of FIG. 1;

FIG. 13 shows an EC in the vehicle engine shown in FIG.
It is a diagram for explaining the driving range map used for U.

FIG. 14 is a diagram showing an EC in the vehicle engine shown in FIG. 1;
It is a diagram for explaining the driving range map used for U.

FIG. 15 shows an EC in the vehicle engine shown in FIG.
6 is a flowchart for explaining the operation of U.

FIG. 16 shows an EC in the vehicle engine shown in FIG. 1;
6 is a flowchart for explaining the operation of U.

FIG. 17 shows a relationship between a return torque and a rotation speed for maintaining rotation with respect to a load on the engine side in an all-cylinder / rest-cylinder state for explaining a problem in the automobile engine shown in FIG. 1; FIG.

FIG. 18 is a diagram for explaining a map for setting a solenoid valve switching prohibition time.

FIG. 19 shows the EC in the vehicle engine shown in FIG.
6 is a flowchart for explaining the operation of U.

FIG. 20 shows an EC in the vehicle engine shown in FIG.
It is a diagram for explaining the air conditioner determination map used for U.

FIG. 21 shows an EC in the vehicle engine shown in FIG.
6 is a flowchart for explaining the operation of U.

FIG. 22 is a diagram showing EC in the automobile engine shown in FIG. 1;
6 is a flowchart for explaining the operation of U.

[Explanation of symbols]

 Reference Signs List 1 intake path 4 ISC valve 8 throttle opening sensor 10 boost pressure sensor 12 rotation speed sensor 13 cylinder head 15 ECU 21 knock sensor 23 spark plug 24 igniter 25 igniter 27 idle switch 29 air conditioner switch 32 power steering switch 33 crank angle sensor 62 operation Valve device 86 Hydraulic control device K1 Low speed switching mechanism K2a High speed switching mechanism K2b High speed switching mechanism

──────────────────────────────────────────────────続 き Continuation of the front page (51) Int.Cl. ⁷ Identification code FI F02D 45/00 312 F02D 45/00 312D 312L (56) References JP-A-60-40739 (JP, A) JP-A-60- 62631 (JP, A) JP-A-60-45738 (JP, A) JP-A-60-40738 (JP, A) JP-A-2-245433 (JP, A) JP-A-62-168936 (JP, A) JP-A-60-138237 (JP, A) JP-A-60-138235 (JP, A) JP-A-60-50240 (JP, A) JP-A-1-208527 (JP, A) (JP, U) (58) Field surveyed (Int. Cl. ⁷ , DB name) F02D 17/02-45/00

Claims (4)

(57) [Claims] An automotive engine in which some of the cylinders are deactivated according to the operating state of the engine, a rotational speed sensor for detecting an engine rotational speed, and boost pressure information for detecting an intake pipe negative pressure are output. Different from the boost pressure sensor
The above engine speed and boost pressure information where the cylinder rest area is set
Multiple judgment maps based on the
Load sensor and the judgment
An engine for a vehicle , comprising: a control device for switching a top . 2. The load sensor according to claim 1, wherein the load sensor comprises an idle switch, and the control device selects a map having a lower lower limit engine speed in the cylinder-stop region when the output of the load sensor detects an idle state. The vehicle engine according to claim 1, wherein: 3. The vehicle engine according to claim 1, wherein said load sensor detects whether the air conditioner is operating or not. 4. The vehicle engine according to claim 1, wherein the transition to the cylinder-stop operation is prohibited for a predetermined time after the transition to the all-cylinder operation even if the cylinder-stop transition condition is satisfied.