JP2005009363A - Cylinder deactivation switching control device for internal combustion engine with cylinder deactivation switching mechanism - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cylinder deactivation switching control device for an internal combustion engine with a cylinder deactivation switching mechanism switching the cylinder deactivation switching mechanism by using engine water temperature without providing a new sensor and securing smooth cylinder deactivation switching by estimating oil pressure at low cost. <P>SOLUTION: The cylinder deactivation switching control device for a multi-cylinder internal combustion engine provided with a cylinder deactivation switching mechanism 20 switching a movable state and a deactivation state of opening and closing of an intake and an exhaust valves of part of cylinders by hydraulic is provided with an engine water temperature detection means 43 detecting temperature of cooling water cooling the internal combustion engine, a deactivation switching permission zone storing means storing the upper limit of engine water temperature permitting cylinder deactivation switching, and a switching permission means permitting switching the movable state and the deactivation state of the intake and the exhaust valves by the cylinder deactivation switching mechanism 20 only when engine water temperature detected by the engine water temperature detection means 43 is in a deactivation switching permission zone below the upper limit stored by the deactivation switching permission zone storing means. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a cylinder deactivation switching control device for a multi-cylinder internal combustion engine having a cylinder deactivation switching mechanism that switches hydraulically between a movable state and an inactive state of intake and exhaust valve opening / closing of some cylinders.
[0002]
[Prior art]
By performing cylinder deactivation according to the operating state of the internal combustion engine, fuel consumption can be reduced.
Therefore, in the cylinder deactivation switching control device of a multi-cylinder internal combustion engine having such a cylinder deactivation switching mechanism, the temperature of the cooling water for cooling the internal combustion engine (engine water temperature) is set to a predetermined temperature or more as one condition. There is an example in which control for stopping is performed (for example, see Patent Document 1).
[0003]
[Patent Document 1]
Japanese Patent Laid-Open No. 2001-227369
[Problems to be solved by the invention]
The reason why the engine water temperature is a predetermined temperature or more in Patent Document 1 is that the activation temperature of the catalyst is a problem, but when the engine water temperature is high, the cylinder intake / exhaust valve open / closed movable state and inactive state are determined. The oil pressure of the oil pressure to be switched is high, and the viscosity of the oil is lowered, and the generated oil pressure is lowered.
[0005]
If the cylinder deactivation switching mechanism tries to perform switching in a state where the hydraulic pressure is not sufficient, it does not operate smoothly and there is a time delay from when the switching command is issued until it is actually operated and switching is performed, and prompt switching control is performed. You can't expect.
[0006]
Therefore, it is conceivable to separately prepare a hydraulic pressure sensor or an oil temperature sensor and perform the switching control based on the oil pressure and the oil temperature. However, it is necessary to provide a new sensor, which increases the cost.
[0007]
The present invention has been made in view of the above points, and the object of the present invention is to estimate the hydraulic pressure for switching the cylinder deactivation switching mechanism using the engine water temperature without providing a new sensor, thereby ensuring smooth cylinder deactivation switching. Therefore, the cylinder deactivation switching control device for an internal combustion engine with a cylinder deactivation switching mechanism is provided at a low cost.
[0008]
[Means for solving the problems and effects]
In order to achieve the above object, according to the first aspect of the present invention, a cylinder of a multi-cylinder internal combustion engine provided with a cylinder deactivation switching mechanism that hydraulically switches between a movable state and an inactive state of intake and exhaust valve opening / closing of some cylinders. In the deactivation switching control device, an engine water temperature detecting means for detecting the temperature of the cooling water for cooling the internal combustion engine, a deactivation switching allowable area storing means for storing an upper limit of the engine water temperature for permitting cylinder deactivation switching, and the engine water temperature detecting means The intake / exhaust valve opening / closing movable state and the idle state are switched by the cylinder deactivation switching mechanism only when the engine water temperature detected by the engine is within the deactivation switching allowable region below the upper limit stored in the deactivation switching allowable region storage means. A cylinder deactivation switching control device for an internal combustion engine with a cylinder deactivation switching mechanism provided with a switching allowance means for allowing
[0009]
The engine water temperature detecting means that is normally provided for detecting the operating state of the internal combustion engine is used to determine the upper limit of the engine water temperature that allows the cylinder deactivation switching by checking the oil pressure. By permitting switching only when the engine is within the allowable switching limit range below the upper limit, smooth switching can be ensured without time delay.
[0010]
According to a second aspect of the present invention, there is provided a cylinder deactivation switching control apparatus for a multi-cylinder internal combustion engine having a cylinder deactivation switching mechanism that switches hydraulically between a movable state and an inactive state of intake / exhaust valve opening / closing of some cylinders. The engine water temperature detecting means for detecting the temperature of the cooling water to be cooled, the engine speed detecting means for detecting the engine speed of the internal combustion engine, and a preset cylinder deactivation switching allowable region at the engine water temperature and the engine speed are stored. The engine switching temperature detected by the engine switching water temperature detecting means, the engine water temperature detected by the engine water temperature detecting means, and the engine speed detected by the engine speed detecting means are within the engine switching switching allowable area stored in the engine switching switching allowable area storage means. An internal combustion engine with a cylinder deactivation switching mechanism provided with switching permission means for permitting switching between the movable state and deactivation state of the intake / exhaust valve opening / closing by the cylinder deactivation switching mechanism only at certain times A cylinder deactivation switching controller.
[0011]
Using the engine water temperature detection means and the engine speed detection means that are normally provided to detect the operating state of the internal combustion engine, the oil pressure is estimated in the stop switching allowable region that allows the cylinder stop switching at the engine water temperature and the engine speed. Thus, by allowing the switching only when the detected engine water temperature and the engine speed are within the permissible switching allowable range, smooth cylinder switching without time delay can be ensured.
[0012]
According to a third aspect of the present invention, in the cylinder deactivation switching control device for an internal combustion engine with a cylinder deactivation switching mechanism according to the first or second aspect of the present invention, the deactivation switching allowable area storage means stores a predetermined time after the start of the internal combustion engine. The present invention is characterized in that it includes a deactivation switching allowable area changing means for reducing and setting a deactivation switching allowable area of the cylinder.
[0013]
Immediately after start-up, the oil pressure for cylinder deactivation switching has begun to rise, and since it has not reached the oil pressure for smooth switching, the deactivation allowance area of the cylinder is reduced for a predetermined time after the start-up so that the switching is easily performed. By setting the normal stop switching allowable area after a predetermined time, a large normal stop switching allowable area can be secured.
[0014]
According to a fourth aspect of the present invention, in the cylinder deactivation switching control apparatus for an internal combustion engine with a cylinder deactivation switching mechanism according to the second or third aspect of the present invention, the switching permission means is configured such that the engine water temperature and the engine speed are outside the deactivation switching allowable range. When shifting from the transition to the rest switching allowable region, switching is permitted after a predetermined time has elapsed since the transition.
[0015]
Immediately after the engine water temperature and the engine speed have shifted from outside the stop switching allowable region to within the stop switching allowable region, the engine water temperature and the engine speed may return to outside the stop switching allowable region again. If this happens, it will be outside the permissible switching range and will not be able to be switched, and the preferred cylinder operating state will be changed, so when transitioning to the permissible switching range, allowing switching after a predetermined time from the transition, Such a problem can be avoided.
[0016]
According to a fifth aspect of the present invention, in the cylinder deactivation switching control device for an internal combustion engine with a cylinder deactivation switching mechanism according to the fourth aspect of the present invention, the predetermined time is set to be small according to the engine speed.
[0017]
The higher the engine speed is, the more stable the engine is operating, and it is less likely to return to the outside of the stop switching allowable range immediately after shifting to the stop switching allowable range. It is possible to set a small value in accordance with the number, and it is possible to perform cylinder deactivation switching at an early stage while reducing unnecessary waiting time as much as possible.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment according to the present invention will be described with reference to FIGS.
As shown in FIG. 1, an OHC type four-stroke cycle internal combustion engine 1 mounted on a motorcycle (not shown) has a three-cylinder cylinder in front of the vehicle body with a crankshaft (not shown) oriented in the vehicle width direction. A 6-cylinder front / rear V-type internal combustion engine in which a row (front bank Bf) and a 3-cylinder cylinder row (rear bank Br) at the rear of the vehicle body form a depression angle of approximately 60 degrees in the front-rear direction, such an OHC 4-stroke The main body of the cycle internal combustion engine 1 includes a cylinder block 2, a crankcase 3 that is integrally attached to the lower surface of the cylinder block 2, and a cylinder row at the front of the vehicle body and a top end of the cylinder row at the rear of the vehicle body. The cylinder heads 4 and 4 are mounted integrally, and the head covers 5 and 5 cover the tops of the cylinder heads 4 and 4, respectively.
[0019]
Intake devices such as fuel injectors and intake chambers (not shown) are arranged in the space between the front and rear banks Bf and Br of the OHC type four-stroke cycle internal combustion engine 1 and the front and rear of the cylinder heads 4 and 4 of the front and rear banks Bf and Br. An exhaust pipe (not shown) is connected to the outside.
[0020]
Among the front and rear banks Bf and Br, the valve operating device 10 of the rear bank Br incorporates a cylinder deactivation switching mechanism 20 that is actuated by hydraulic pressure. FIG. 2 shows a part of the cylinder deactivation switching mechanism 10 on the intake side as a cylinder. A portion viewed from above the head 4 in the direction of the central axis of the cylinder is shown, and a part thereof is shown in cross section.
[0021]
The valve operating apparatus 10 is disposed in a valve operating chamber 11 formed by a cylinder head 4 coupled to the upper end of the cylinder block 2 and a head cover 5 coupled to the upper end of the cylinder head 4.
[0022]
A combustion chamber is formed between a piston slidably fitted to each cylinder formed in the cylinder block 2 and the cylinder head 4, and the cylinder head 4 has an intake port communicating with each combustion chamber. And an exhaust port is formed, and the camshaft 12 that is driven to rotate at half the rotational speed of the crankshaft driven by the piston is connected to the cylinder head 4 at intervals in the direction of the rotation axis of the camshaft 12. It is inserted through insertion holes of a plurality of cam holders that are integrally molded, and is rotatably supported by the journal portion.
[0023]
For each combustion chamber, a pair of intake valves and a pair of exhaust valves that are slidably supported by the cylinder head 1 include a cam shaft 12, cams 13, 14, 15 provided on the cam shaft 12, and a rocker shaft. 16, is operated by a valve gear 10 including rocker arms 17, 18, 19 supported on the rocker shaft 16 so as to be swingable, and a cylinder deactivation switching mechanism 20, and each of the intake ports is disposed on the combustion chamber side at a predetermined timing. A pair of openings and a pair of openings on the combustion chamber side of the exhaust port are opened and closed.
[0024]
The cylinders in a part of the rear bank Br of the internal combustion engine 1 are deactivated during fuel-intensive operation such as during low-load operation. For this reason, the valve train 10 of the rear bank Br includes the intake air during cylinder deactivation operation. A cylinder deactivation switching mechanism 20 is provided for keeping the valve and the exhaust valve closed.
[0025]
Hereinafter, the cylinder deactivation switching mechanism 20 provided on the intake valve side will be mainly described with reference to FIG.
The camshaft 12 has an intake cam 13, a pair of pause cams 14 located on both sides of the intake cam 13, and an intake cam 13 and both pause cams 14. A pair of exhaust cams 15 is provided.
[0026]
The intake cam 13 and the exhaust cam 15 have a cam profile including a base circle portion and a nose portion having a predetermined lift amount and operating angle, and the pause cam 14 includes a base circle portion of the intake cam 13 and the exhaust cam 15. A cam profile having only a base circle portion having the same radius is provided, and the intake valve and the exhaust valve are kept closed during partial cylinder deactivation.
[0027]
The rocker shaft 16 inserted through the insertion holes of the plurality of rocker shaft holders fastened by bolts to the cylinder head 4 has a pair of drive rocker arms 17 and 18 corresponding to each combustion chamber, and between them. The free rocker arm 19 to be arranged is supported so as to be swingable.
[0028]
Slippers 17a and 18a are formed at one end of each drive rocker arm 17 and 18 so as to be in sliding contact with the rest cam 14, and tappet screws 17b and 18b are provided at the other end to abut against the intake valve.
[0029]
On the other hand, a roller 19a that is in rolling contact with the intake cam 13 is rotatably supported at one end of the free rocker arm 19, and the free rocker arm 19 is attached to the intake cam 13 by a spring of a lost motion mechanism supported by the cylinder head 4. It is energized towards.
[0030]
In addition, a cylinder deactivation switching mechanism 20 is provided between the drive rocker arms 17 and 18 and the free rocker arm 19 so as to be able to switch the connection and release of the drive rocker arms 17 and 18 and the free rocker arm 19.
[0031]
The cylinder deactivation switching mechanism 20 regulates movement of the coupling pin 22, a coupling piston 21 that can couple the drive rocker arm 17 and the free rocker arm 19, a coupling pin 22 that can couple the driving rocker arm 9 and the free rocker arm 10, and the like. A release piston 23 for releasing the connection between the drive rocker arms 17 and 18 and the free rocker arm 19, a return spring 24 for bringing the connection pin 22 into contact with the connection piston 21 and bringing the release piston 23 into contact with the connection pin 22; The hydraulic oil which is formed on the rocker arm 17 and moves the connecting piston 21 is supplied and discharged and the return spring 24 is accommodated, and the hydraulic oil which is formed on the drive rocker arm 18 and moves the release piston 23. A second hydraulic chamber 26 is supplied and discharged.
[0032]
A hollow portion of each cylindrical rocker shaft 16 is formed by a first hydraulic oil passage 28 formed between the pipe 27 and the rocker shaft 16 and a hollow portion of the pipe 27 by a pipe 27 inserted into the hollow portion. The formed second hydraulic oil passage 29 is partitioned.
[0033]
The first hydraulic chamber 25 is always in communication with the first hydraulic fluid passage 28 via a communication passage 30 formed in the drive rocker arm 17, and the second hydraulic chamber 26 is in communication with the drive rocker arm 18 and the pipe 27. It always communicates with the second hydraulic oil passage 29 via the passage 31.
[0034]
The first and second hydraulic oil passages 28 and 29 are hydraulic control valve devices 42 (FIG. 3) attached to the cylinder head 4 through two first and second oil passages 32 and 33 formed in the cylinder head 4, respectively. Communication).
An oil pump that operates by driving the internal combustion engine 1 is used as a hydraulic pressure source.
[0035]
On the other hand, on the exhaust side, the valve operating characteristic changing mechanism on the exhaust valve side provided straddling between a pair of drive rocker arms 36 and a pair of free rocker arms 37 supported swingably on the rocker shaft 25, A connecting piston capable of connecting the drive rocker arm 36 and the free rocker arm 37, and a release piston for restricting the movement of the connecting piston and releasing the connection between the drive rocker arm 36 and the free rocker arm 37 are provided. Similarly to the valve operating characteristic changing mechanism T on the side, it is operated by the hydraulic pressure of the hydraulic oil in the first and second hydraulic oil passages 28 and 29.
[0036]
During all-cylinder operation, the first hydraulic fluid passage 28 is communicated with the high-pressure fluid passage via the first oil passage 32 by the hydraulic control valve device 42 that is controlled according to the driving state of the vehicle. Becomes the high hydraulic pressure, while the second hydraulic oil passage 29 is communicated with the drain oil passage via the second oil passage 33, and the hydraulic oil becomes the low hydraulic pressure.
[0037]
As a result, the connecting piston 21 presses the connecting pin 22 and the release piston 23 due to the differential pressure between the first and second hydraulic chambers 25 and 26, and the contact surface between the connecting piston 21 and the connecting pin 22 is free rocker arm. The drive rocker arms 17 and 18 and the free rocker arm 19 are connected to each other with the contact surface between the connection pin 22 and the release piston 23 positioned on the drive rocker arm 18. As a result, the swing of the drive rocker arms 17 and 18 is defined by the cam profile of the intake cam 13, and the intake valve is opened and closed with a predetermined opening / closing timing and lift amount. Similarly, the exhaust valve is opened and closed with a predetermined opening / closing timing. And opened and closed by lift amount.
[0038]
In the partial cylinder deactivation operation, the hydraulic control valve device 42 causes the first hydraulic oil passage 28 to communicate with the drain oil passage through the first oil passage 32, and the hydraulic oil has a low hydraulic pressure. The hydraulic oil passage 29 is communicated with the high-pressure oil passage through the second oil passage 33, and the hydraulic oil becomes a high hydraulic pressure.
[0039]
As a result, the first hydraulic chamber 25 has a low hydraulic pressure, the second hydraulic chamber 26 has a high hydraulic pressure, and is released from the state shown in FIG. 2 by the differential pressure between the first and second hydraulic chambers 25 and 26. The piston 23 presses the connecting piston 21 and the connecting pin 22, and the contact surface between the connecting piston 21 and the connecting pin 22 is positioned between the drive rocker arm 17 and the free rocker arm 19. Is placed between the drive rocker arm 17 and the free rocker arm 19, so that the drive rocker arm 17 and the free rocker arm 19, and the drive rocker arm 18 and the free rocker arm 19 are disconnected.
[0040]
As a result, the swinging of the drive rocker arms 17 and 18 is respectively defined by the cam profile of the stop cam 14, the intake valve is closed, and the exhaust valve is closed as well. The cylinder enters a resting state.
[0041]
In the cylinder deactivation switching mechanism 20 as described above, when the operating hydraulic pressure is in a low state, the second hydraulic pressure is changed when the hydraulic control valve device 42 is operated to switch from the full cylinder operation (the state shown in FIG. 2) to the cylinder deactivation operation. Since the hydraulic pressure introduced into the chamber 26 is low and the force for sliding the release piston 23 is weak, the release of the connection state between the free rocker arm 19 and the drive rocker arms 17 and 18 may be delayed for several cycles.
[0042]
The same occurs when switching from the cylinder deactivation operation to the all cylinder operation, and even if there is a switching command and the hydraulic control valve device 42 is activated, a delay occurs in actually performing the switching and the responsiveness. Smooth and smooth switching control is not possible.
[0043]
Therefore, the cylinder deactivation switching control device 40 according to the present embodiment estimates the hydraulic pressure from the temperature of the cooling water (engine water temperature) for cooling the internal combustion engine 1 by the electronic control unit ECU 41 and the rotation speed of the crankshaft (engine rotation speed). Thus, the hydraulic control valve device 42 is controlled.
[0044]
FIG. 3 shows a schematic block diagram of the cylinder deactivation switching control device 40.
The ECU 41 has inputs from the engine water temperature sensor 43, the engine speed sensor 44, and other various sensors that indicate the operating state of the internal combustion engine 1, and performs various operation controls, one of which is cylinder deactivation switching control. A switching control signal is output to the hydraulic control valve device 42.
The cylinder deactivation switching mechanism 20 is driven and controlled by the hydraulic control valve device 42.
[0045]
In this cylinder deactivation switching control, a control procedure for determining whether or not to allow switching regarding hydraulic pressure will be described with reference to FIG.
First, the engine water temperature Tw detected by the engine water temperature sensor 43 and the engine speed Ne detected by the engine speed sensor 44 are input (step 1).
[0046]
Then, it is determined whether or not a predetermined time has elapsed after starting (step 2). If the predetermined time has not elapsed, the process proceeds to step 3 to change the Tw-Ne map stored in advance, and if the predetermined time has elapsed, step Go to 4 to return the Tw-Ne map to the normal map.
[0047]
Here, as shown in FIG. 5, the Tw-Ne map divides the coordinate space into a switching allowable area and a switching prohibited area by a threshold line L in a rectangular coordinate having the horizontal axis as the engine water temperature Tw and the vertical axis as the engine speed Ne. It is a thing.
[0048]
Threshold line L is a line, the engine coolant temperature Tw until _{t 1} is threshold line _{l 1} is constant rotational speed _{n 1} is the engine rotational speed Ne, a predetermined rotation the engine speed Ne is the engine coolant temperature Tw is _{t 2} or more The threshold line l ₃ is the number n ₂ , and when t ₁ <Tw <t ₂ , the threshold line l ₂ is an oblique threshold line l ₂ connecting the end portions of the threshold line l ₁ and the threshold line l ₃ .
[0049]
The upper side of the threshold line L is a switching allowable region, and the lower side is a switching prohibited region.
It is possible to determine in which region the set (point coordinates (Tw, Ne)) of the detected engine water temperature Tw and the engine speed Ne (point coordinates (Tw, Ne)) is located.
[0050]
The threshold line L of this Tw-Ne map is determined in advance by experiments. If the set of the engine water temperature Tw and the engine speed Ne is within the switching allowable range, the cylinder deactivation switching mechanism 20 is quickly activated (the connected piston 21, This is to delimit a switching allowable region where it can be determined that there is sufficient hydraulic pressure to slide the connecting pin 22 and the release piston 23.
[0051]
And shows a region when threshold line L shown by a solid line in Tw-Ne map of FIG 5 is in the normal operating state, the switching allowable area to move threshold line l ₁ is upward until a predetermined time elapses after start Is changed to a threshold line l ₁ ′ (represented by a broken line) for reduction (step 3).
[0052]
In other words, immediately after starting, the hydraulic pressure for cylinder deactivation switching has started to rise, and since the hydraulic pressure for smooth switching has not been reached, switching is easily performed by reducing the cylinder switching allowable area for a predetermined time after starting. The normal switching allowable area is set after a predetermined time so that a large normal switching allowable area can be secured.
[0053]
When the process proceeds from step 3 or step 4 to step 5, the region is determined from the Tw-Ne map based on the engine water temperature Tw and the engine speed Ne input in step 1.
That is, it is determined whether the set of the engine water temperature Tw and the engine speed Ne is in the switching allowable region or the switching prohibition region in the Tw-Ne map.
[0054]
Then, in the next step 6, it is determined whether or not it is within the switching allowable area, and if it is within the switching allowable area, the process proceeds to step 9; In step 8, the switching permission flag F is set to “0” to prohibit the switching (operation of the cylinder deactivation switching mechanism 20 is prohibited).
[0055]
When the set of the engine water temperature Tw and the engine speed Ne is determined as the switching allowable region in the Tw-Ne map and the process proceeds to step 9, it is determined whether or not the down timer t has timed up (t = 0). Until the time is up, the process proceeds to step 8 and switching is prohibited.
[0056]
Then, when the state where the set of the engine water temperature Tw and the engine speed Ne is in the switching allowable region continues until the down timer expires, the process proceeds to step 10 for the first time and the switching allowable flag F is set to “1” to allow switching (cylinder). The operation of the pause switching mechanism 20 is permitted).
[0057]
When actually performing switching of cylinder deactivation, it is determined from other operating states. However, at least unless the switching permission flag F is set to “1”, the switching, that is, the cylinder deactivation switching mechanism 20 is not operated.
[0058]
If the switching allowance flag F = 1, it is estimated that the hydraulic pressure for operating the cylinder deactivation switching mechanism 20 is sufficient. Therefore, when a switching command is actually output from the ECU 41 to the hydraulic control valve device 42, the hydraulic pressure is sufficiently increased. The cylinder deactivation switching mechanism 20 can be actuated promptly (sliding the coupling piston 21, the coupling pin 22, and the release piston 23) to ensure smooth cylinder deactivation switching without time delay.
[0059]
Since the operating oil pressure is estimated using the engine water temperature sensor 43 and the engine speed sensor 44 that are normally provided to detect the operating state of the internal combustion engine 1, it is necessary to provide a separate oil pressure sensor and oil temperature sensor. The cost can be reduced.
[0060]
Further, in the present embodiment, when the set of the engine water temperature Tw and the engine speed Ne is shifted from the switching prohibition region to the switching allowable region in Step 9 of the flowchart of FIG. Wait until the timer expires.
[0061]
That is, immediately after the set of the engine water temperature Tw and the engine speed Ne shifts from the switching prohibition region to the switching allowable region, the engine water temperature Tw may return to the switching prohibition region again, and switching is executed immediately after the transition to the switching allowable region. Then, it becomes a switching prohibition region and cannot be switched, and the preferable cylinder operation state is changed by a temporary change of the operation state, so when shifting to the switching allowable region, the time from the transition until the down timer expires By allowing switching after the elapse of time, such a problem is avoided.
[0062]
Here, the time set in the down timer t in step 7 is a fixed time, but it may be set to a time corresponding to the engine speed Ne.
FIG. 6 is a graph showing the relationship of the set time t of the down timer to the engine speed Ne prepared in advance.
[0063]
The higher the engine speed is, the more stable the operation state is, and there is little return to the outside of the stop switching allowable region immediately after the transition to the stop switching allowable region. Therefore, the set time t is as shown in FIG. A small value (short time) can be set according to the rotational speed Ne.
[0064]
Since the set time t is a cylinder deactivation switching waiting time, the cylinder deactivation switching is executed early by reducing the unnecessary waiting time as much as possible by setting the set time t shorter as the engine speed Ne is higher. Can do.
[0065]
It is possible to estimate the operating oil pressure only with the engine water temperature, but it is possible to determine the upper limit of the engine water temperature that allows the cylinder deactivation switching by checking the oil pressure, and the detected engine water temperature is less than this upper limit. By allowing the switching only when it is within the switching allowable region, it is possible to ensure smooth cylinder deactivation switching without time delay.
[Brief description of the drawings]
FIG. 1 is an overall side view of an OHC type 4-stroke cycle internal combustion engine according to the present invention.
FIG. 2 is a cross-sectional view of a part of the intake side of the cylinder deactivation switching mechanism as viewed in the direction of the central axis of the cylinder.
FIG. 3 is a schematic block diagram of a cylinder deactivation switching control device.
FIG. 4 is a flowchart showing a control procedure for switching permission determination in the cylinder deactivation switching control device;
FIG. 5 is a diagram showing a Tw-Ne map.
FIG. 6 is a graph showing the relationship of the set time of the timer to the engine speed.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... 4 stroke cycle internal combustion engine, 2 ... Cylinder block, 3 ... Crankcase, 4 ... Cylinder head, 5 ... Head cover,
DESCRIPTION OF SYMBOLS 10 ... Valve operating apparatus, 11 ... Valve operating chamber, 12 ... Cam shaft, 13 ... Intake cam, 14 ... Pause cam, 15 ... Exhaust cam, 16 ... Rocker shaft, 17, 18 ... Drive rocker arm, 19 ... Free rocker arm, 20 DESCRIPTION OF SYMBOLS Cylinder deactivation switching mechanism, 21 ... Connection piston, 22 ... Connection pin, 23 ... Release piston, 24 ... Return spring, 25 ... 1st hydraulic chamber, 26 ... 2nd hydraulic chamber, 27 ... Pipe, 28 ... 1st hydraulic oil 29, second hydraulic oil path, 30 ... communication path, 31 ... communication path, 32 ... first oil path, 33 ... second oil path, 36 ... drive rocker arm, 37 ... free rocker arm,
DESCRIPTION OF SYMBOLS 40 ... Cylinder deactivation switching control apparatus, 41 ... ECU, 42 ... Hydraulic control valve apparatus, 43 ... Engine water temperature sensor, 44 ... Engine speed sensor.

Claims (5)

In a cylinder deactivation switching control device of a multi-cylinder internal combustion engine having a cylinder deactivation switching mechanism that switches hydraulically between a movable state and an inactive state of intake and exhaust valve opening / closing of some cylinders,
Engine water temperature detecting means for detecting the temperature of cooling water for cooling the internal combustion engine;
A deactivation switching allowable region storage means for storing an upper limit of the engine water temperature that allows the deactivation of the cylinder;
Only when the engine water temperature detected by the engine water temperature detecting means is within a stop switching allowable area below the upper limit stored in the stop switching allowable area storage means, the intake / exhaust valve opening / closing movable state by the cylinder stop switching mechanism A cylinder deactivation switching control apparatus for an internal combustion engine with a cylinder deactivation switching mechanism, comprising switching permission means for permitting switching to a deactivation state. In a cylinder deactivation switching control device of a multi-cylinder internal combustion engine having a cylinder deactivation switching mechanism that switches hydraulically between a movable state and an inactive state of intake and exhaust valve opening / closing of some cylinders,
Engine water temperature detecting means for detecting the temperature of cooling water for cooling the internal combustion engine;
Engine speed detecting means for detecting the engine speed of the internal combustion engine;
A deactivation switching allowable area storage means for storing a predetermined deactivation switching allowable area of the cylinder at the engine water temperature and the engine speed;
Only when the engine water temperature detected by the engine water temperature detecting means and the engine speed detected by the engine speed detecting means are within the stop switching allowable area stored in the stop switching allowable area storing means, the cylinder stop switching is performed. A cylinder deactivation switching control apparatus for an internal combustion engine with a cylinder deactivation switching mechanism, comprising switching permission means for permitting switching between a movable state and a deactivation state of intake / exhaust valve opening / closing by the mechanism. 2. A stop switching permissible region changing means for reducing and setting a stop switching permissible region of a cylinder stored in the rest switching permissible region storage means for a predetermined time after starting the internal combustion engine. 3. A cylinder deactivation switching control device for an internal combustion engine with a cylinder deactivation switching mechanism according to 2. 3. The switching permission means, when the engine water temperature and the engine speed shift from outside the stop switching allowable region to within the stop switching allowable region, permit switching after a predetermined time from the transition. A cylinder deactivation switching control device for an internal combustion engine with a cylinder deactivation switching mechanism according to claim 3. 5. The cylinder deactivation switching control device for an internal combustion engine with a cylinder deactivation switching mechanism according to claim 4, wherein the predetermined time is set to be small according to the engine speed.

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