JPH11229835A - Variable valve unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable fine-tuning of valve characteristics in accordance with various situations by providing a cam switching type variable valve train that selectively switches the cam to open/close the engine valves within a several types of cams, and a hydraulic pressure control valve that continuously changes the amount of hydraulic fluid to be supplied to this valve train. SOLUTION: According to a movable cam follower 54 in a cam switching type variable valve train, when the hydraulic pressure in a hydraulic compartment 66 exceeds a predetermined value, a hydraulic piston 59 moves to the right against a coil spring 65. Then, the bottom end face of a leg portion 56 of the movable cam follower 54 is mounted to the inner bottom of the engaging slot 60 with a rectangular cross-section formed in the hydraulic piston 59. Accordingly, sliding movement of the movable cam follower 54 is restricted. In this state, a rocker arm is swung by the high-speed cam. When the hydraulic pressure in the hydraulic compartment 66 lowers and the hydraulic piston 59 is shifted to the left, the movable cam follower 54 is allowed to slide within the rocker arm 25. In this state, the rocker arm is swung by the low-speed cam.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a variable valve operating device, and more particularly to a variable valve operating system in which a valve characteristic is made variable by selectively switching a cam for opening and closing an engine valve.

[0002]

2. Description of the Related Art A variable valve actuation device that changes valve characteristics such as the opening and closing timing of an engine valve and the amount of lift thereof according to the operating state of an internal combustion engine has been proposed and put into practical use. As such a variable valve apparatus, for example, Japanese Patent Publication No. 4-2767 discloses a plurality of cams having different cam characteristics for each cylinder, and selectively changing a cam for driving an engine valve to open and close. A variable valve operating device including a cam switching type variable valve operating mechanism that is variable is described.

[0003] With respect to such a variable valve system,
This will be described with reference to FIGS. 28 and 29. FIG. 28 shows an aspect of the cam switching type variable valve mechanism at the time of engine low speed operation of such a variable valve apparatus, and FIG. 29 shows an aspect of the cam switching type variable valve mechanism at the time of high speed operation of the variable valve apparatus. The internal combustion engine provided with the variable valve operating system is a double overhead camshaft (DOHC) system having two camshafts, one for intake and one for exhaust. It has a four-valve configuration with individual components.

A camshaft of an internal combustion engine provided with the variable valve device includes two low-speed cams for each cylinder and one high-speed cam provided between the low-speed cams. I have. The high-speed cam has a profile with a higher lift portion in order to increase the valve lift and the valve opening / closing period compared to the low-speed cam. A cam switching type variable valve mechanism 100 for opening and closing an engine valve based on the low speed cam and the high speed cam.
As shown in FIGS. 28 and 29, the first rocker arm 105 and the second rocker arm 106 which are rotatably mounted on the rocker shaft 104 and are oscillated by the low-speed cam, and are similarly turned around the rocker shaft 104. A mid rocker arm 107 movably mounted and oscillated by the high-speed cam. The first
And at the tip of the second rocker arms 105 and 106,
Tappet screw 10 abutting on the upper end of engine valve 101
8 are provided.

Further, each rocker arm 105, 106, 1
In 07, receiving holes 109 and 110 and a receiving hole 111 extending in parallel with the rocker shaft 104 are formed.
The first and second switching pins 112 and 113 and the regulating pin 114 are loosely fitted in the accommodation holes 109 and 110 and the accommodation hole 111 so as to be slidable in the axial direction. The regulating pin 114 is urged toward the mid rocker arm 107 by a coil spring 115, and presses the first and second switching pins 112 and 113.

A space 116 between one end of the first switching pin 112 and the closed end of the housing hole 110 is a hydraulic chamber. The hydraulic chamber 116 communicates with an oil passage 119 formed in the second rocker arm 106. This oil passage 1
Reference numeral 19 denotes an oil provided inside the rocker shaft 104 so as to extend in the axial direction of the rocker shaft 104 via an annular oil passage 118 formed in the rocker shaft 104 at a sliding contact portion with the second rocker arm 106. It communicates with the passage 117.

Here, when oil (usually utilizing lubricating oil of an internal combustion engine) is not supplied into the hydraulic chamber 116, each rocker arm 105, 10 is driven in the manner shown in FIG.
6, 107 can freely swing.
That is, at this time, the mid rocker arm 107 which is oscillated by the high-speed cam having a higher lift is separated from the first and second rocker arms 105 and 106 so as to be oscillated in an empty state, and each valve 101 is Driven by the low speed cams through the first and second rocker arms 105 and 106, respectively.

On the other hand, the oil passages 117 and 11
When lubricating oil is supplied via the first and second lubricating oils 8 and 119, the first and second switching pins 112 and 113 and the regulating pin 114 are opposed to the urging force of the coil spring 115 by the oil pressure as shown in FIG. To the first rocker arm 105 side. By this movement, the first and second switching pins 11
The rocker arms 105, 106 and 2113 are inserted between the housing holes 110 and 111 and between the housing holes 111 and 109, respectively.
107 are connected and swing together. That is, at this time, these rocker arms 105, 106,
107 and each valve 101 are driven by a high-speed cam having a higher lift.

Next, the configuration of a hydraulic circuit for supplying lubricating oil to the cam switching type variable valve mechanism 100 in the same device will be described with reference to FIG. In FIG. 30, a cam 102 is the low-speed cam, and a cam 103 is the high-speed cam. Cam rocker arms 105, 106, and 107 that constitute the cam switching type variable valve mechanism 100 are respectively opposed to these cams 102, 103.

Now, in the hydraulic circuit shown in FIG.
The oil pump 32 sucks the lubricating oil in the oil pan 69 and, at the same time,
This is the part that pressurizes and discharges the lubricating oil. The oil switching valve 121 is formed of an electromagnetic three-port directional control valve.
The first port 122 of the oil switching valve 121 is an inlet for lubricating oil, and is connected to the hydraulic supply path 120. Second
The port 123 is connected to an oil passage 125 that supplies lubricating oil to the low-speed cam 102. The third port 124 is
Oil passage 117 formed in the rocker shaft 104
Is connected to an oil passage 126 for supplying the lubricating oil to the cam switching type variable valve mechanism 100 via the. An oil passage 127 for supplying lubricating oil to the high-speed cam 103 and the bearing 96 of the cam shaft is connected to the rear end of the oil passage 117 via an orifice 128.

A guide hole 128 is provided in the oil switching valve 121.
Is formed therein, and a spool 129 is slidably inserted therein. The spool 129 is urged downward by the spring 131 in FIG. 30. When the solenoid 130 is excited, the spool 129 is attracted to the position shown in FIG. 30 against the urging force. In this state, the first port 122 and the third port 124 are connected. When the solenoid 130 is demagnetized, the spool 129 is actuated by the biasing force of the spring 131 in FIG.
Move down. In this state, the first port 122 and the second port 123 are connected. At this time, the first port 122 and the third port 124 are also connected by the small-diameter bypass passage 133 formed in the spool 129.

That is, in such a device, when the internal combustion engine is operating at a high speed, the solenoid 130 is excited, and the lubricating oil is supplied to the cam switching type variable valve mechanism 100 via the first port 122 and the third port 124. Is done. With this oil pressure, the rocker arms 105 to 107 of the cam switching type variable valve mechanism 100 are connected, and the engine valve 101 is opened and closed by the high speed cam 104 (FIG. 2).
9). At this time, a small amount of lubricating oil is supplied to the oil passage 127 through the orifice 128 to lubricate the high-speed cam 104 and the bearing 96 of the camshaft.

On the other hand, during low-speed operation, the solenoid 130
Is demagnetized, and the lubricating oil is supplied to the low-speed cam 103 via the first port 122 and the second port 123. At the same time, a small amount of lubricating oil is supplied to the oil passage 126 via the bypass passage 133. At this time, the lubricating oil supplied to the oil passage 126 is supplied to the high-speed cam 104 and the bearing 96 of the camshaft via the orifice 128, and the lubrication thereof is maintained. However, since the amount of lubricating oil supplied to the oil passage 124 at this time is small,
The hydraulic pressure in the hydraulic chamber 116 does not become high enough to move each of the pins 112 to 114 against the urging force of the coil spring 115. Therefore, each rocker arm 105-107
Swing independently, and the engine valve 101 is opened and closed by the low speed cam 103 (FIG. 28).

As described above, in this hydraulic circuit, even when non-hydraulic oil is supplied to the cam switching type variable valve mechanism 100, a small amount of lubricating oil is continuously supplied through the bypass passage 133, so that each of the cams 102, 103 And bearing part 9 of camshaft
Lubrication for lubricating parts such as 6 is maintained. Further, each oil passage 117, 1 for supplying lubricating oil to the mechanism 100 is provided.
By maintaining the fluidity of the lubricating oil in 26, the responsiveness at the time of cam switching is improved.

[0015]

In such a variable valve operating system, the oil supplied to the cam switching type variable valve operating system varies depending on the change in the viscosity of the lubricating oil due to the temperature and the operating state of the internal combustion engine. The amount varies. For this reason, it is desirable that the amount of lubricating oil supplied to the variable valve mechanism be finely adjusted according to the situation. However, in the conventional variable valve apparatus that supplies the lubricating oil through the hydraulic circuit having the above-described configuration, it is not possible to finely adjust the supply amount of the lubricating oil in response to such a change in the situation.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide a variable valve operating device capable of performing fine hydraulic pressure and liquid amount control on its mechanism section according to various situations. Is to provide.

[0017]

In order to achieve the above object, according to the first aspect of the present invention, a cam for selectively opening and closing an engine valve is selected from a plurality of types of cams based on hydraulic pressure control of hydraulic fluid. SUMMARY OF THE INVENTION The gist of the present invention is to provide a cam-switching type variable valve mechanism for switching to a variable pressure valve mechanism and a hydraulic pressure control valve capable of continuously changing the amount of hydraulic fluid supplied to the cam-switching type variable valve mechanism. .

According to this configuration, the amount of hydraulic fluid supplied to the cam switching type variable valve mechanism by the hydraulic pressure control valve can be continuously varied. Therefore, it is possible to perform fine fluid pressure and fluid volume control for the cam switching type variable valve mechanism according to the situation, and to stabilize the variable valve apparatus and improve responsiveness. become able to.

According to the second aspect of the present invention, in the variable valve operating apparatus according to the first aspect, the operation of supplying the cam to the cam switching type variable valve mechanism prior to the cam switching operation by the mechanism. The gist of the invention is to provide a preceding hydraulic pressure control means for controlling the hydraulic pressure control valve so as to raise the liquid pressure to a predetermined hydraulic pressure in advance.

According to this configuration, the hydraulic fluid is pressurized beforehand during the cam switching operation by the cam switching type variable valve mechanism, and the hydraulic pressure of the hydraulic fluid is increased to the hydraulic pressure necessary for the cam switching operation of the same mechanism. The time it takes to do so can be reduced. Therefore, the responsiveness of the cam switching type variable valve mechanism can be improved.

Further, in the invention according to the third aspect, the preceding hydraulic pressure control means controls the engine at a predetermined rotational speed lower than an engine rotational speed at which a cam switching operation by the cam switching type variable valve mechanism is performed. The gist of the invention is to control the hydraulic pressure control valve so as to increase the pressure to a predetermined hydraulic pressure.

With this configuration, when the rotation speed of the internal combustion engine approaches the rotation speed at which the cam switching operation of the cam switching type variable valve mechanism is performed, the hydraulic pressure is increased in advance. Therefore, the hydraulic fluid is pre-pressurized at the time of the cam switching operation, and the time required to raise the pressure to the required hydraulic pressure can be reduced. Thus, the responsiveness of the variable valve operating device can be improved.

According to a fourth aspect of the present invention, in the variable valve apparatus according to the second or third aspect, the preceding hydraulic pressure control means controls the predetermined hydraulic pressure to be increased in advance in accordance with an engine temperature. The gist of the present invention is to provide a temperature correcting means for correcting.

The viscosity of the working fluid changes depending on the temperature.
At high temperatures, the viscosity of the working fluid decreases, and pressure fluctuations generated in other parts of the internal combustion engine are easily propagated. for that reason,
The fluctuation amount of the working fluid supplied to the cam switching type variable valve mechanism increases. According to this configuration, by correcting the pressure of the hydraulic fluid that is boosted before the cam switching operation of the cam switching variable valve mechanism according to the temperature, the cam switching variable valve mechanism caused by the pressure fluctuation of the hydraulic fluid is corrected. The occurrence of a malfunction can be suppressed.

According to a fifth aspect of the present invention, there is provided the variable valve apparatus according to any one of the first to fourth aspects, wherein the cam is switched at a time other than when the cam is switched by the cam switching type variable valve mechanism. The gist of the invention is to provide a constant hydraulic pressure control means for controlling the hydraulic pressure control valve so as to constantly supply a predetermined amount of hydraulic fluid to the switching type variable valve mechanism.

According to this configuration, a predetermined amount of hydraulic fluid is always supplied to the cam switching type variable valve mechanism even when the cam switching operation is not being performed by the cam switching type variable valve mechanism. Working fluid used for lubrication and the like can be secured. Also, the fluidity of the hydraulic fluid in the hydraulic fluid passage used for supplying the hydraulic fluid to the cam switching type variable valve mechanism is always maintained, so that the responsiveness of the mechanism can be improved. Become.

In the invention according to claim 6, the gist of the invention is that the constant hydraulic pressure control means further includes a temperature correction means for correcting the amount of the constantly supplied hydraulic fluid in accordance with the engine temperature. .

As described above, since the viscosity of the hydraulic fluid changes depending on the temperature, even if the opening amount of the hydraulic pressure control valve is kept constant, the amount of the hydraulic fluid discharged from the valve also changes. According to this configuration, the opening amount of the hydraulic pressure control valve is corrected in accordance with the temperature of the hydraulic fluid, so that the hydraulic fluid supplied at any time other than during the cam switching operation by the cam switching type variable valve mechanism is always an appropriate amount. Will be able to do it.

According to a seventh aspect of the present invention, in the variable valve apparatus according to the first aspect, a hydraulic pressure detecting means for detecting a hydraulic pressure of hydraulic fluid supplied to the cam switching type variable valve mechanism. And a feedback control unit that performs feedback control of the opening amount of the hydraulic pressure control valve so that the hydraulic pressure detected by the hydraulic pressure detection unit converges to a target predetermined hydraulic pressure.

According to this configuration, the hydraulic pressure of the hydraulic fluid is determined,
Based on this, the opening of the hydraulic control valve can be feedback controlled. Therefore, more appropriate hydraulic pressure and fluid amount control can be performed for the cam switching type variable valve mechanism.

In the invention described in claim 8, in the variable valve operating apparatus according to claim 7, the feedback control means performs the same prior to the cam switching operation by the cam switching type variable valve mechanism. A predetermined amount of operation is always performed on the cam switching type variable valve mechanism other than at the time of changing the cam by the preceding hydraulic pressure and the cam switching type variable valve mechanism determined to supply the pressurized hydraulic fluid to the mechanism in advance. The gist is that at least one of the constant hydraulic pressures set to supply the liquid is set as the target predetermined hydraulic pressure, and the opening of the hydraulic control valve is feedback-controlled.

According to this configuration, the hydraulic fluid supplied to the cam switching type variable valve mechanism as the preceding hydraulic pressure or the constant hydraulic pressure is
The adjustment can be performed based on the feedback control of the opening amount of the hydraulic pressure control valve. In this way, the amount of the hydraulic fluid supplied as the preceding hydraulic pressure or the constant hydraulic pressure or the hydraulic pressure can be more appropriately adjusted.

According to a ninth aspect of the present invention, in the variable valve operating device according to any one of the first to eighth aspects, the cam-switching type variable valve operating mechanism is configured such that each of the cam switching type variable valve operating mechanisms is partitioned within a support shaft thereof. A cam that opens and closes the engine valve is selected from three types of cams having two hydraulic pressure control mechanisms that are hydraulically controlled based on hydraulic fluids separately supplied through different hydraulic fluid supply passages. The gist of the invention is that the partitioning means for partitioning the working fluid supply passage in the support shaft is formed with a small-diameter communication hole communicating between the respective different working fluid supply passages. .

According to this configuration, when the hydraulic fluid is supplied to one of the two hydraulic control mechanisms, the hydraulic fluid is also supplied to the other hydraulic control mechanism through the communication hole. It will be. By appropriately setting the diameter of the communication hole, a desired amount of hydraulic fluid can be supplied to another hydraulic pressure control mechanism. Using the supplied hydraulic fluid, lubrication of the sliding contact portion of the cam switching type variable valve mechanism and the like and fluidity of the hydraulic fluid in the hydraulic fluid passage can be maintained. Therefore, the responsiveness of the variable valve device can be improved and stabilized.

According to a tenth aspect of the present invention, in the variable valve operating device according to any one of the first to eighth aspects, the cam-switching type variable valve operating mechanism is configured such that each of the cam switching type variable valve operating mechanisms is divided within a support shaft thereof. A cam that opens and closes the engine valve is selected from three types of cams having two hydraulic pressure control mechanisms that are hydraulically controlled based on hydraulic fluids separately supplied through different hydraulic fluid supply passages. The gist is that the partitioning means for partitioning the hydraulic fluid supply passage in the support shaft is helically extended in the axial direction of the support shaft.

According to the above configuration, the working fluid supply path formed in the support shaft for supplying the working fluid to the two hydraulic pressure control mechanisms is not parallel to the axis of the support shaft, but the axis of the support shaft. Is stretched so as to spiral around the. Therefore, by adjusting the torsion interval of the partition member, the direction of the position of the connection portion between the cam switching type variable valve mechanism and the hydraulic fluid supply passage can be freely set.

According to the eleventh aspect of the present invention, in the variable valve device according to any one of the first to tenth aspects,
A phase displacement type variable valve mechanism that varies the rotation phase between the engine output shaft and the camshaft based on hydraulic pressure control of the hydraulic fluid, and a phase displacement that controls the amount of hydraulic fluid supplied to the phase displacement type variable valve mechanism And a hydraulic pressure control valve, wherein the hydraulic pressure control valve supplies hydraulic fluid branched and supplied from a hydraulic fluid discharge part of the phase displacement hydraulic pressure control valve to the cam switching type variable valve mechanism. This is the gist.

According to this structure, the hydraulic fluid supply path for the cam switching type variable valve mechanism and the hydraulic fluid supply path for the phase displacement type variable valve mechanism can be provided substantially in series, and the hydraulic fluid supply path can be provided. Can be shortened. Therefore, it is possible to simplify the hydraulic fluid supply path and reduce the amount of consumed oil.

According to a twelfth aspect of the present invention, in the variable valve operating apparatus according to the eleventh aspect, the cam switching type variable valve mechanism is provided in a valve operating system on the engine intake side, and the phase displacement type valve operating mechanism is provided. The gist is that the variable valve mechanism is provided in a valve train on the engine exhaust side.

According to this configuration, the effect of improving the maximum output by the cam switching type variable valve mechanism can be achieved while suitably avoiding the trouble caused by the interference between the head portion of the engine valve and the upper end surface of the piston and the fluctuation of the cam drive torque. In addition, the effect of improving emission and fuel efficiency by the phase displacement type variable valve mechanism can be further enhanced.

[0041]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) A first embodiment of the present invention will be described below.
The variable valve apparatus according to the present embodiment is provided with a hydraulic control valve, and is configured as a variable valve apparatus that can arbitrarily control the amount of lubricating oil and oil pressure supplied to a cam switching switching type variable valve mechanism. I have.

First, a schematic configuration of an internal combustion engine provided with the variable valve apparatus according to the present embodiment will be described with reference to FIG. The internal combustion engine 1 is a DOHC type internal combustion engine using gasoline as fuel and having two camshafts provided in a cylinder head. The internal combustion engine 1
Is an in-line four-cylinder type in which four cylinders are arranged in series, and a four-valve type in which each cylinder is provided with two intake valves and two exhaust valves. In FIG. 1, for convenience, members that are provided symmetrically in the intake system and the exhaust system of the internal combustion engine 1 and have basically the same functions are denoted by the same reference numerals, and in particular, the members of the intake system. Are distinguished by appending “i” to the end of them and attaching “e” to the end of exhaust system members. Further, in the following description, when the identifiers i and e at the end of the reference numerals of these members are omitted, both members of the intake system and the exhaust system are indicated unless otherwise specified.

The internal combustion engine 1 includes a cylinder block 2 and a cylinder head 3 provided on the cylinder block 2.
And a cylinder bore 4 formed in the cylinder block 2
And a piston 5 that reciprocates inside. The piston 5 is connected to a crankshaft 7 via a connecting rod 6. This crankshaft 7
Is rotated when the piston 5 reciprocates.

A crank pulley 23 is connected to the crankshaft 7 so as to be integrally rotatable. Further, a disk-shaped rotor 8 is attached to the shaft 7 so as to be integrally rotatable. A predetermined number of protrusions are formed on the outer periphery of the rotor 8. A crank angle sensor 9 is provided near the rotor 8. The crank angle sensor 9 detects a convex portion of the rotor 8 by an electromagnetic pickup and outputs a pulse signal. Based on a signal output from the crank angle sensor 9, an electronic control unit (hereinafter, referred to as “ECU”) 10 calculates the rotation speed of the crankshaft 7, that is, the engine rotation speed NE and the rotation phase of the shaft 7. I do.

A space for flowing cooling water is formed in the cylinder block 2. The cylinder block 2 is provided with a cooling water temperature sensor 26 for detecting the temperature of the cooling water, that is, the cooling water temperature thw. The cooling water temperature thw reflects the temperature state of the internal combustion engine 1 and has a direct correspondence with the lubricating oil temperature described later. Therefore, it is possible to grasp the temperature of the lubricating oil from the cooling water temperature thw.

A space 11 defined by the inner walls of the cylinder head 3 and the cylinder bore 4 and the upper end surface of the piston 5 serves as a combustion chamber for burning an air-fuel mixture. An ignition plug 35 for igniting the air-fuel mixture in the combustion chamber 11 is provided at the upper center of the combustion chamber 11. Further, the combustion chamber 11 is connected to an intake port 12i for supplying an air-fuel mixture to the combustion chamber 11 and an exhaust port 12e for discharging combustion gas from the same chamber 11. In the combustion chamber 11, these intake and exhaust ports 12
i, 12e are connected to intake valves 13i, respectively.
And an exhaust valve 13e. The intake valve 13i and the exhaust valve 13e are slidably supported by the cylinder head 3. In addition, these valves 1
3i, 13e, each port 12i, 12e
e and the combustion chamber 11 are communicated or shut off.

On the other hand, an intake pipe 14i and an exhaust pipe 14e are connected to the intake port 12i and the exhaust port 12e, respectively.
Is connected. In the intake pipe 14i, an injector 15 for injecting and supplying fuel to the combustion chamber 11 is provided near a connection between the intake port 12i and the combustion chamber 11. A throttle valve 16 for adjusting the amount of intake air introduced into the combustion chamber 11 is provided upstream of the injector 15 in the intake pipe 14i. The throttle valve 16 is driven to open and close based on depression of an accelerator pedal 17.

Further, the tip of the intake pipe 14i is connected to an air cleaner 1 for purifying air introduced into the pipe 14i.
8 is connected. Downstream of the air cleaner 18, an air flow meter 19 for detecting an amount of air flowing through the intake pipe 14i, that is, an intake air amount Q is provided. The load state of the internal combustion engine 1 can be grasped from the intake air amount Q.

Next, the structure of the valve train in the internal combustion engine 1 for opening and closing the intake valve 13i and the exhaust valve 13e will be described with reference to FIG. In the upper part of the cylinder head 3, the intake / exhaust valve 13
i, 13e, above the intake side camshaft 2
0i and the exhaust side camshaft 20e are rotatably supported. These camshafts 20i and 20e are connected to the intake-side cam pulley 21i and the exhaust-side cam pulley 21e, respectively, so as to be integrally rotatable. These cam pulleys 21 are drivingly connected to the crank pulley 23 via a timing belt 22 at a reduction ratio of 1/2. As a result, each camshaft 20 makes one rotation every time the crankshaft 7 makes two rotations.

The camshaft 20 is provided with two cams for each cylinder, that is, a low-speed cam 29 and a high-speed cam 31 so as to be integrally rotatable. The cam profile of the high-speed cam 31 is set such that at least one of the lift amount and the valve opening period of the engine valve 13 driven to open and close by the low-speed cam 29 is increased. In the present embodiment, the cam profile of the high-speed cam 31 is set such that both the lift amount and the valve opening timing are large.

Each of these camshafts 20i and 20e
Below, are provided an intake side rocker shaft 24i and an exhaust side rocker shaft 24e, respectively. Each of the rocker shafts 24i and 24e is rotatably mounted with a cam-switching type variable valve mechanism 50 configured around a rocker arm 25 for each cylinder. The rocker arm 25 is in contact with the heads of the pair of engine valves 13. The rocker arms 2 are actuated by the urging force of a valve spring 28 provided on each engine valve 13.
5 is urged toward cams 29 and 31 provided on the camshaft 20. Then, as the camshaft 20 rotates, the rocker arm 25 is pressed by the lift portion of the cam, and swings around the rocker shaft 24. Each valve 13 is driven to open and close as the rocker arm 25 swings. In the following, the side of the rocker arm 25 supported by the rocker shaft 24 is referred to as a base end side, and the side in contact with the head of the valve 13 is referred to as a distal end side.

Next, the structure of the cam-switching type variable valve mechanism 50 composed mainly of the rocker arm 25 will be described in detail with reference to FIGS. FIG. 2 shows a planar structure of the cam-switching type variable valve mechanism 50, and FIGS. 3 and 4 show cross-sectional structures of a hydraulic lock mechanism provided in the mechanism 50.

As shown in FIG. 2, the rocker arm 25 is formed in a substantially planar rectangular shape, and the base end thereof is supported by the rocker shaft 24 as described above. Two arms 5 from the tip side of the rocker arm 25
1 is formed so as to extend obliquely forward, and the distal end thereof can contact the head of the valve 13 (FIG. 1).

On the upper surface of the rocker arm 25, a roller follower 52 is rotatably supported. The roller follower 52 is rotatable with the low-speed cam 29. Further, a guide hole 53 having a circular cross section is formed vertically downward on the upper surface of the rocker arm 25 and on the side (the right side in FIG. 2) of the roller follower 52. In the guide hole 53, as shown in FIGS.
A movable cam follower 54 having a substantially cylindrical shape is slidably inserted. The movable cam follower 54 includes a slipper 55 having a rectangular cross section provided on the head and a leg 56 having a cylindrical shape so as to be inserted into the guide hole 53.
It is composed of The upper end surface of the slipper 55 is shown in FIG.
In the mode shown in FIG. 4, the surface has an arc shape, and can slide on the high-speed cam 31. Also, slippers 55
A lost motion spring 57 is disposed between the lower end surface of the rocker arm 25 and the upper surface of the rocker arm 25. The movable cam follower 54 includes a lost motion spring 57
Urged toward the high-speed cam 31 (FIGS. 1 and 2). The spring force of the lost motion spring 57 is set sufficiently smaller than the spring force of the valve spring 28 (FIG. 1).

On the other hand, as shown in FIGS. 3 and 4, below the rocker arm 25, a cylinder hole 58 having a circular cross section orthogonal to the guide hole 53 is formed from the tip end side of the rocker arm 25. A substantially cylindrical hydraulic piston 59 is inserted into the cylinder hole 58, and is slidable between a position shown in FIG. 3 and a position shown in FIG.

FIG. 5 shows a perspective structure of the hydraulic piston 59. An engagement groove 60 having a rectangular cross section is formed from the tip to the center of the hydraulic piston 59, and a pair of side sides 61 are provided with the groove 60 interposed therebetween. The inner bottom portion 62 of the engagement groove 60 is a flat surface, and serves as a support portion capable of contacting and supporting the bottom surface of the leg portion 56 (FIGS. 3 and 4) of the movable cam follower 54. On the other hand, the inner bottom of the front end side 63 of the groove 60 is cut out, and only the side 61 is projected. As shown in FIG. 3 (b) and FIG. 4 (b), the leg 56 of the movable cam follower 54 has a cross-sectional structure. Are formed, and the leg portion 56 can be inserted into the groove 60 through the plane portion thereof.

That is, the hydraulic piston 59 is
When the movable cam follower 54 is located at the position shown in (a) or (b), the leg 56 of the movable cam follower 54 is located at the notch of the engagement groove 60, and the cam follower 54 slides freely in the guide hole 53. It becomes possible. On the other hand, as shown in FIG.
When it is located at the position shown in (b), the leg portion 56 of the movable cam follower 54 has its bottom surface in contact with and supported by the support portion 62 of the engagement groove 60, and the sliding of the movable cam follower 54 is restricted.

Further, a spring receiving member 64 is disposed in the engagement groove 60, and a coil is provided between the spring receiving member 64 and the hydraulic piston 59 in the manner shown in FIGS. A spring 65 is provided. The coil spring 65 urges the spring receiving member 64 toward the movable cam follower 54 and also urges the hydraulic piston 59 toward the inner bottom surface of the cylinder hole 58, that is, toward the base end of the rocker arm 25.

Here, a space 66 formed between the inner bottom surface of the cylinder hole 58 and the proximal end surface of the hydraulic piston 59 is a hydraulic chamber. This hydraulic chamber 66 communicates with an oil passage 67 formed in the rocker arm 25. In addition,
The oil passage 67 has a rocker shaft oil passage 68 (FIG. 2) formed in the rocker shaft 24 along the axis thereof.
Is in communication with

That is, in the cam switching type variable valve mechanism 50 configured as described above, when the pressure of the lubricating oil supplied into the hydraulic chamber 66 increases to a certain degree or more, the hydraulic piston 59 applies the urging force of the coil spring 65. 3 from the position shown in FIG. 3 to the position shown in FIG. 4 to limit the sliding of the movable cam follower 54 in the rocker arm 25.
The movable follower 54 whose sliding is restricted in this way swings integrally with the rocker arm 25 based on the rotation and pressing of the high-speed cam 31 (FIGS. 1 and 2).

On the other hand, when the pressure of the lubricating oil supplied into the hydraulic chamber 66 decreases, the hydraulic piston 59 moves from the position shown in FIG. 4 to the position shown in FIG. Is rocker arm 25
It can slide freely inside. At this time, the movable cam follower 54 is separated from the rocker arm 25, so that the movable cam follower 54 swings in an empty manner, and the rocker arm 25 swings based on the rotation and pressing of the low-speed cam 29 (FIGS. 1 and 2).

In the present embodiment, the sliding of the movable cam follower 54 in the guide hole 53 is restricted or restricted by the hydraulic piston 59, the coil spring 65, and the hydraulic chamber 66 provided in the cylinder hole 58. A hydraulic lock mechanism for releasing the restriction (hereinafter, simply referred to as “lock mechanism”) is configured.

Next, the configuration of a hydraulic circuit for supplying lubricating oil to the cam switching type variable valve mechanism 50 will be described with reference to FIG. The oil pump 32 sucks the lubricating oil in the oil pan 69 and actually pressurizes and discharges the lubricating oil to the lubricating oil supply passage 36 formed in the cylinder block 2 and the cylinder head 3 (FIG. 1). For convenience, each oil passage including the supply passage 36 is schematically shown). The lubricating oil supply passage 36 is provided with an oil passage 37 for supplying lubricating oil as a working oil to the cam switching type variable valve mechanism 50.
And a lubricating path 49 for supplying lubricating oil to the bearings of the camshaft 20 and the lubricating parts such as the cams 29 and 31.

The oil passage 37 is provided with a hydraulic control valve (hereinafter referred to as “OC”).
V ") 33. This OCV33
Is to continuously vary the amount of lubricating oil supplied to or discharged from the cam switching type variable valve mechanism 50.
It is a port type hydraulic control valve. In addition to the oil passage 37, the OCV 33 has a drain passage 38 for returning lubricating oil into an oil pan 69, and a cylinder oil passage 39 actually formed in the cylinder block 2 and the cylinder head 3. Is connected. The cylinder oil passage 39 is connected to a rocker shaft oil passage 68 formed in the rocker shaft 24, and is used for supplying lubricating oil to the cam switching type variable valve mechanism 50.

On the other hand, the oil supply passage 49 is actually extended above the cylinder head 3, and is a discharge port for jetting lubricating oil to each bearing of the camshaft 20 and each of the cams 29, 31 in a shower shape. It is connected to.

Next, regarding the structure of the above-described OCV 33,
This will be described in detail with reference to FIGS. As described above, the OCV 33 controls the hydraulic pressure supplied to the lock mechanism and each sliding portion of the cam switching type variable valve mechanism 50 (FIG. 1). The OCV 33 is mounted on the outer wall of the cylinder head 3 in a manner shown in FIGS. 6 and 7, and is connected to the oil passage 37 receiving lubricating oil from the oil pump 32 (FIG. 1). A port 40, a second port 41 connected to the cylinder oil passage 39, and a third port 42 connected to the drain passage 38 are provided. O
A spool 43 having a hollow cylindrical shape is slidably provided in the CV 33. The spool 43 is continuously movable between a first operating position shown in FIG. 6 and a second operating position shown in FIG. Annular grooves 44 and 45 are formed on the outer periphery of the spool 43. A plurality of holes are formed in the inner bottom portion of one of the grooves 44.
4 communicates with a hole 46 formed inside the spool 43 through the plurality of holes.

That is, when the spool 43 is located at the first operating position shown in FIG. 6, the second port 41 and the third port 42 are communicated via the groove 44 and the hole 46. Therefore, the cylinder oil passage 39 and the drain passage 3
The lubricating oil in the hydraulic chamber 66 (FIGS. 3 and 4) of the rocker arm 25 is discharged through the drain passage 38. On the other hand, in the second operating position shown in FIG. 7, the first port 40 and the second port 41 are communicated via the groove 45. Therefore, the oil passage 37 and the cylinder oil passage 39
The lubricating oil pressurized and discharged by the oil pump 32 is supplied into the hydraulic chamber 66 (FIGS. 3 and 4) of the cam switching type variable valve mechanism 50 via the oil passages 37 and 39 and the like. You. Further, at a position intermediate between the first and second operating positions, the opening amounts of the ports 40, 41 and the grooves 44, 45 change, and the amount of lubricating oil flowing through the ports 40, 41, 42 also increases. It changes continuously.

The spool 43 is provided with the coil spring 4
6 is pressed toward the first operating position shown in FIG. On the other hand, an electromagnetic solenoid 49 is housed at the tip side of the OCV 33, and a voltage whose duty is controlled by the ECU 10 shown in FIG. 1 is applied to the electromagnetic solenoid 49. When a voltage is applied to the electromagnetic solenoid 49, the generated electromagnetic force causes the spool 43 and the regulating pin 47 to move toward the second operating position against the urging force of the coil spring 48. Therefore, the duty ratio of the voltage applied to the electromagnetic solenoid 49 controls the opening amount of each port 40, 41 and each groove 44, 45, thereby reducing the amount of lubricating oil flowing through each port 40, 41. Be able to adjust. Thus, the supply amount of the lubricating oil to the cylinder oil passage 39 is continuously variable, and the oil pressure in the passage 39 and the hydraulic chamber 66 (FIGS. 3 and 4) of the cam switching type variable valve mechanism 50 is continuously adjusted. Be able to adjust.

Next, the electrical configuration of the control system of the variable valve apparatus according to the present embodiment will be described with reference to FIG.
The ECU 10 is mainly configured by a microcomputer 70 as shown in a block diagram in FIG.

The microcomputer 70 includes various control programs for controlling the variable valve operating device, fuel injection control and ignition timing control of the internal combustion engine 1, and maps for calculating values corresponding to various conditions. And a read-only memory (ROM) 71 storing the same. The microcomputer 70 includes a central processing unit (CPU) 72 that executes arithmetic processing based on a program stored in the ROM 71, and temporarily stores an arithmetic result of the CPU 72, data input from each sensor, and the like. A random access memory (RAM) 73 for storing data, a backup RAM 74 for holding necessary data even when power supply to the ECU 10 is cut off, and the like are provided. These CPUs
72, ROM 71, RAM 73 and backup RA
M74 are connected to each other via a bus 75,
The input port 76 and the output port 77 are also connected.

On the other hand, in the ECU 10, the input signals from the air flow meter 19 and the cooling water temperature sensor 26 are taken into the buffers 78 and 79. The input signals taken into the buffers 78 and 79 are appropriately selected by the multiplexer 80, converted to digital signals by the A / D converter 81, and sent to the input port 76. The input signal from the crank angle sensor 9 is sent to the input port 76 after being binarized by the waveform shaping circuit 82. The output port 77 has an OCV
33 drive circuits 83 are connected. This drive circuit 8
Reference numeral 3 denotes a voltage whose duty ratio has been adjusted under the control of the microcomputer 70 (CPU 72).
3 to drive it.

Next, the ECU 10 (CPU 72)
The processing operation related to the control of the variable valve operating device, which is executed through, will be described with reference to FIGS. 9 to 14. FIG.
5 is a flowchart showing a control routine of the variable valve operating device. This routine is executed by the CPU 72 as a periodic interruption process at predetermined time intervals.

When the process of the CPU 72 shifts to the present routine, first, as a process of step S201, the CPU 72 executes the engine speed NE detected based on the output of the crank angle sensor 9, the intake air amount Q detected by the air flow meter 19, and The cooling water temperature thw detected by the cooling water temperature sensor 26 is read and stored in the RAM 73.

As the processing of the subsequent step S202, the CPU
72 determines a control region of the variable valve device corresponding to the current operating state of the internal combustion engine 1 from a two-dimensional map of the engine speed NE and the intake air amount Q stored in the ROM 73. FIG. 10 shows an example of the two-dimensional map. FIG. 10
In the map, a region R1 is a control region (a non-operating region of the lock mechanism) for driving the engine valve 13 to open and close by the low-speed cam 29, and a region R3 is a control region (locking) for driving the engine valve 13 to open and close by the high-speed cam 31. (Operating region of the mechanism). A region R2 between the region R1 and the region R3 is provided with a variable valve operating device in advance to ensure high responsiveness at the time of cam switching while driving the engine valve 13 by the low-speed cam 29. The preceding hydraulic pressure supply area for supplying hydraulic pressure is shown.

If it is determined in step S202 that the operating region of the internal combustion engine 1 is in the control region R1, the CPU 72 proceeds to step S203.
In this step S203, the CPU 72 calculates the duty command value IOCVduty from the map A which is a one-dimensional map based on the cooling water temperature thw stored in the ROM 73 as shown in FIG. The duty command value IOCVduty is equal to the electromagnetic solenoid 49 of the OCV 33.
The spool 43 of the OCV 33 moves to the second operating position shown in FIG. 7 as the duty ratio of the voltage applied to the spool 43 increases. The opening amount between the first port 40 and the second port 41 increases as the position moves toward the second operation position, and the supply amount of the lubricating oil to the lubricating oil passage 39 increases. As is apparent from the characteristics of map A shown in FIG. 11, the duty command value IOCVd
The value of uty increases as the cooling water temperature thw decreases.

As described above, the cooling water temperature thw reflects the temperature state of the internal combustion engine 1, and the cooling water temperature thw
It is possible to grasp the temperature state of the lubricating oil from w.
Duty command value I calculated in step S203
The OCV duty is an OCV 33 that can supply lubricating oil that does not impair the fluidity in the lubricating cylinder oil passage 39 or the like in accordance with the viscosity of the lubricating oil that changes depending on the temperature state.
The value is set in order to secure the opening amount of.

After the duty command value IOCVduty is set by the processing in step S203, the CPU
72 shifts to the processing of step S206. In this step S206, the CPU 72 executes the processing in step S20.
3. Duty command value IOCVdut set in 3.
y to the drive circuit 83 of the OCV 33. The drive circuit 83 applies a voltage adjusted to a duty ratio corresponding to the duty command value IOCVduty to the electromagnetic solenoid 48 of the OCV 33. By applying this voltage, the opening of the OCV 33 is adjusted in accordance with the map A, and the rocker arm 25 is moved through the cylinder oil passage 39 and the like.
A desired amount of lubricating oil is supplied into the hydraulic chamber 66. At this time, the hydraulic chamber 66 of the cam switching type variable valve mechanism 50
Since the amount of lubricating oil supplied to the inside is small, the hydraulic piston 59 is maintained in the state illustrated in FIG. 3, and the engine valve 13 is opened and closed by the low speed cam 29.

Incidentally, since the lubricating oil is also supplied to other parts of the internal combustion engine 1, for example, a bearing portion of the crankshaft 7, the amount of the lubricating oil supplied to the variable valve apparatus should be reduced as much as possible. Is desirable. In particular, at a high temperature at which the viscosity of the lubricating oil decreases, the lubricating oil easily leaks from the clearance of the sliding contact portion or the like, so that the lubrication of the cam switching type variable valve mechanism 50 when the lock mechanism is in the non-operating region. It is better to reduce the oil supply. On the other hand, when the temperature is low, the viscosity of the lubricating oil increases, so the first port 4 of the OCV 33
When the opening amount between the first port 0 and the second port 41 is small, each oil passage 3
It becomes difficult to ensure the fluidity of the lubricating oil in 9, 67, 68.

FIG. 13A shows the relationship between the cooling water temperature thw and the opening amount of the OCV 33 in the control region R1, the viscosity of the lubricating oil, and the amount of the leaking lubricating oil. Also,
FIG. 13 (b) shows the state of O 2 regardless of the temperature state of the internal combustion engine 1.
A similar relationship is shown when the opening of the CV 33 is constant.

As shown in FIG. 13B, the OCV 33
When the opening amount of the lubricating oil is constant, in order to secure the fluidity even at a low temperature where the viscosity of the lubricating oil increases, the OCV 33
It is necessary to set a large opening amount in advance. Therefore, at a high temperature at which the viscosity of the lubricating oil decreases, a large amount of the lubricating oil leaks and is wasted. In this regard, as in the present embodiment, the opening amount of the OCV 33 in the control region R1 is made variable in accordance with the temperature state in the mode shown in FIG. In addition, the fluidity of the lubricating oil can be ensured even at low temperatures.

If it is determined in step S202 that the operating region of the internal combustion engine 1 is in the preceding hydraulic pressure supply region R2, the CPU 72 proceeds to step S204. In this step S204, the CPU
Reference numeral 72 denotes a duty command value IOCV from a map B which is a one-dimensional map based on the cooling water temperature thw as shown in FIG.
Calculate the duty. The duty command value IOCVduty calculated in step S204 is as shown in FIG.
The pressure required for operating the lock mechanism of the cam switching type variable valve mechanism 50 shown in FIG.
The OCV 33 is capable of supplying an amount of lubricating oil that moves slightly against the urging force of the coil spring 65 and has a pressure slightly lower than the pressure required to limit the sliding of the movable cam follower 54 with respect to the rocker arm 25. The value is set in order to secure the opening amount of. In addition, as is clear from the above map B, when the cooling water temperature thw is high and the viscosity of the lubricating oil is low, hydraulic pressure fluctuations in other lubricating systems are easily transmitted, and this may cause malfunction of the hydraulic piston 59. When the cooling water temperature thw becomes higher than a predetermined temperature, a smaller value is set as the duty command value IOCVduty in consideration of the possibility that the cooling water temperature thw becomes higher than a predetermined temperature.

Thereafter, the CPU 72 proceeds to step S described above.
The process proceeds to step 206, where the opening amount of the OCV 33 is adjusted. At this time, the hydraulic chamber 66 of the cam switching type variable valve mechanism 50
Is insufficient for the movement of the hydraulic piston 59, and the state in which the engine valve 13 is driven to open and close by the low-speed cam 29 is maintained.

Further, when it is determined that the operation region of the internal combustion engine 1 is in the operation region R3 by the process of step S202, the CPU 72 shifts to a process of step S205. In this step S205, the CPU 72
The duty command value IOCVduty is changed to a duty ratio of 10
0% or a value corresponding to a duty ratio close to 0%. Thereafter, the process of the CPU 72 shifts to the process of step S206 described above, and the opening amount of the OCV 33 is adjusted. In this case, the opening between the first port 40 and the second port 41 of the OCV 33 is set to a maximum or an opening close to the maximum, and a large amount of lubricating oil is supplied to the cylinder oil passage 39. Then, as the oil pressure in the oil pressure chamber 66 increases, the lock mechanism is operated. That is, the hydraulic piston 59 moves against the urging force of the coil spring 65, and restricts the sliding of the movable cam follower 54 with respect to the rocker arm 25 in the mode illustrated in FIG. Accordingly, the movable cam follower 54 pressed by the high-speed cam 31 swings integrally with the rocker arm 25, and the engine valve 13 also moves the high-speed cam 3
1 to open and close.

As described above, in this embodiment, prior to the engine speed NE at which the switching from the low-speed cam 29 to the high-speed cam 31 is performed, the preceding hydraulic pressure is applied to the variable valve operating device in advance. I have.

FIG. 14 shows time t and engine speed N
E, hydraulic pressure in the hydraulic chamber 66, duty command value IOCVd
This shows the relationship with the util. Here, a case will be described where the intake air amount Q is constant and the engine speed NE monotonically increases with time t. This engine speed N
The regions R1, R2, and R3 shown in FIG. 14 regarding the transition of E correspond to the control region R1, the preceding hydraulic pressure supply region R2, and the control region R3 illustrated in FIG. 10, respectively. In FIG. 14, solid lines L1 and L3 indicate the case where the preceding hydraulic pressure is applied as in the present embodiment.
Numeral 4 indicates a case where the preceding hydraulic pressure is not applied.

In other words, when the preceding hydraulic pressure is applied, FIG.
4, the duty command value IOCV
The duty becomes the value calculated in the process of step S204 once when the operation region of the internal combustion engine 1 shifts from the control region R1 to the preceding hydraulic pressure supply region R2, and then becomes the duty when the shift to the control region R3 occurs. The value corresponds to a duty ratio of 100% or a duty ratio close thereto. On the other hand, when the preceding hydraulic pressure is not applied, the one-dot chain line L4 in FIG.
As shown in the above, at the time of shifting to the control region R3, the duty command value IOCVduty becomes a value corresponding to a duty ratio of 100% or a duty ratio close thereto.

Here, the CPU 72 sends the duty command value IOCVdut to the drive circuit 83 of the OCV 33.
Even if y is output, there is a delay in the response of the OCV 33 and the time until the lubricating oil reaches the hydraulic chamber 66 via the oil passages 39, 68, 67, and the like. Does not immediately reach the desired pressure. Therefore, when the preceding hydraulic pressure is not applied, as shown by the one-dot chain line L2, the hydraulic pressure in the hydraulic chamber 66 starts rising only after the shift to the control region R3, and the hydraulic pressure piston 59 can be moved by this. That is, it takes time t until the cam for opening and closing the engine valve 13 is switched to the high-speed cam 31.
2 are required. On the other hand, when the preceding hydraulic pressure is applied, as shown by the solid line L1, the rise of the same hydraulic pressure is started at the time of shifting to the preceding hydraulic pressure supply region R2. It has risen to the leading hydraulic pressure. Therefore, after shifting to the control region R3, it is only necessary to increase the hydraulic pressure in the hydraulic chamber 66 by the difference between the pressure required to move the hydraulic piston 59 and the preceding hydraulic pressure. As shown in FIG. 14, only time t1 occurs. By applying the preceding hydraulic pressure in this manner, the low-speed cam 29 to the high-speed cam 3
The responsiveness for switching the cam to 1 can be greatly improved.

As described above, the lubricating oil is supplied to the internal combustion engine 1.
Because it is also used for other parts such as lubrication parts and other hydraulic control mechanisms, a sudden change in the amount of lubricating oil supplied as hydraulic oil to the variable valve device causes sudden oil pressure fluctuations,
It may also affect other parts using the lubricating oil. In this regard, in the present embodiment, the leading hydraulic pressure is applied in advance, and the supply amount of the lubricating oil is increased in two stages, so to say, such a fluctuation in the hydraulic pressure can be suppressed, and the influence on other parts can be reduced. become able to.

On the other hand, if the supply amount of the lubricating oil supplied to other parts changes suddenly, the lubricating oil supplied to the variable valve apparatus may fluctuate in oil pressure, contrary to the above. In particular, at high temperatures, the viscosity of the lubricating oil decreases, and hydraulic pressure fluctuations generated in other parts are easily propagated. Therefore, at such a high temperature, the pressure in the hydraulic chamber 66 temporarily increases due to the hydraulic pressure fluctuation generated in other parts when the preceding hydraulic pressure is applied, and the cam switching type variable valve mechanism 50 malfunctions, that is, the lock mechanism operates. A malfunction may occur. In this regard, in the present embodiment, the OCV 3 at the time of applying the preceding hydraulic pressure is set according to the temperature state of the internal combustion engine 1.
3, the leading hydraulic pressure is controlled to be lower at high temperatures, which are susceptible to fluctuations in hydraulic pressure. Therefore, the cam switching type variable valve mechanism 50 can be prevented from malfunctioning, and the cam can be controlled over the entire temperature range. As high a response as possible at the time of switching can be secured.

As a result of the control of the variable valve gear, a small amount of lubricating oil always flows in the lubricating oil passages 39, 67, 68 extending from the OCV 33 to the hydraulic chamber 66 even in the control region R1. become. Thus, the lubricating oil is continuously supplied to the sliding contact portion between the rocker arm 25 and the rocker shaft 20 and the sliding contact portion between the movable cam follower 54 and the guide hole 53 shown in FIG. In addition, each oil passage 39, 6
The fluidity of the lubricating oil in 4-66 will be secured,
The lubricating oil can be quickly supplied to the hydraulic chamber 66 even at a low temperature where the viscosity of the lubricating oil increases.

According to the embodiment described above, the following effects can be obtained. (1) A hydraulic control valve (O) capable of continuously changing the amount of lubricating oil supplied to the cam switching type variable valve mechanism 50
By adopting the CV 33), the cam switching type variable valve mechanism 50 can be finely controlled according to various situations.

(2) Even when the cam switching is not performed, by always supplying a small amount of lubricating oil to the cam switching type variable valve mechanism 50, it is possible to maintain the lubrication of the sliding portion and the like. In addition, since the fluidity of the lubricating oil in the oil passage reaching the cam switching type variable valve mechanism 50 is always maintained, high responsiveness can be ensured even at a low temperature when the viscosity of the lubricating oil increases. .

(3) By making the amount of lubricating oil supplied to the cam switching type variable valve mechanism 50 variable according to the temperature state of the internal combustion engine, it is possible to reduce the waste of lubricating oil at high temperatures and to reduce Even at times, sufficient lubricating oil can be supplied.

(4) The responsiveness at the time of cam switching is greatly improved by preliminarily applying a preceding hydraulic pressure to the cam switching type variable valve mechanism 50 (lock mechanism) when switching the cam. Can be improved. Also, when switching the cam,
In order to gradually increase the amount of lubricating oil supplied to the cam switching type variable valve mechanism 50, hydraulic pressure fluctuations caused by a sudden change in the lubricating oil supply amount are suppressed, and other parts of the internal combustion engine using lubricating oil are used. Impact on the vehicle can be reduced.

(5) By making the supply amount of the preceding hydraulic pressure variable according to the temperature state of the internal combustion engine, the malfunction of the cam switching type variable valve mechanism 50 is prevented, and the highest possible responsiveness is ensured. Will be able to do it.

The above embodiment can be implemented by changing its configuration as follows. In the present embodiment, the control in the control region R1 and the control in the preceding hydraulic pressure supply region R2 are performed together. However, if at least one of these controls is performed, the above (1) and ( 4) Alternatively, an effect similar to the effects of the above (1) to (3) can be obtained.

In this embodiment, the description has been given of the cam switching type variable valve mechanism for switching between two kinds of cams, that is, a low speed cam and a high speed cam. However, for example, two or more movable cam followers are provided. The hydraulic circuit and the control device according to the present embodiment can also be applied to a cam switching type variable valve mechanism that switches between three or more types of cams for low speed, medium speed, and high speed. . However, in this case, it is necessary to provide an OCV capable of independently controlling the hydraulic pressure and a separate lubricating oil supply path for the lock mechanism of each movable follower.

The cam switching type variable valve mechanism is not limited to a cam switching type variable valve mechanism in which the cam for opening and closing the engine valve is switched by restricting / allowing the sliding of the movable cam follower as in the present embodiment. Switching type variable valve mechanism, for example, FIG.
9 and a plurality of rocker arms oscillating corresponding to a plurality of types of cams as shown in FIG. 30, and a cam for opening and closing an engine valve by connecting (locking) and separating (unlocking) these rocker arms. The hydraulic circuit and the control device according to the present embodiment can also be applied to a cam switching type variable valve mechanism of a switching type.

(Second Embodiment) Next, a second embodiment of the present invention will be described. The variable valve apparatus according to the present embodiment is the same as the variable valve apparatus according to the first embodiment described above, except that the pressure in the supply path of the lubricating oil is detected, and the opening of the OCV is feedback-controlled based on this pressure. It is something to do. The present embodiment is common to the first embodiment in most of its configuration, and includes a hydraulic circuit for supplying lubricating oil (hydraulic oil) to the cam switching type variable valve mechanism 50, and Only a part of the control device differs from the first embodiment. Therefore, here, the same or corresponding elements will be denoted by the same reference symbols, without redundant description, and mainly the different parts will be described.

FIG. 15 shows a configuration of a hydraulic circuit employed in the variable valve apparatus according to the present embodiment. In the cylinder oil passage 39 connected to the first port 41 of the OCV 33 (see FIGS. 6 and 7 for details), near the connection with the rocker shaft oil passage 68 formed in the rocker shaft 24, A hydraulic pressure sensor 34 for detecting the pressure of the lubricating oil flowing in the passage 39 is provided. The electric signal output from the oil pressure sensor 34 is an EC signal shown in detail in FIG.
In U10, the signal is once taken into a buffer (not shown), is appropriately selected by the multiplexer 80, is converted into a digital signal by the A / D converter 81, and is sent to the input port 76 of the microcomputer 70.

Next, a control operation of the variable valve apparatus according to the present embodiment, which is executed by the CPU 72, will be described with reference to FIG. FIG. 16 is a flowchart illustrating a control routine of the variable valve operating device according to the present embodiment. This routine is executed by the CPU 72 as a periodic interruption process at predetermined time intervals.

When the process of the CPU 72 shifts to this routine, first, as a process of step S301, the CPU 72 executes an engine speed NE detected based on an output of the crank angle sensor 9 and an intake air amount Q detected by the air flow meter 19. Are read and stored in the RAM 73.

Next, as the processing of step S302, the CP
U72 is based on the two-dimensional map of the engine speed NE and the intake air amount Q as shown in FIG. 6, as in the process of step S202 of the control routine of the first embodiment.
The operating range of the engine valve 13 is controlled by the low speed cam 29.
Region R1 for opening and closing the cam, similarly for the low speed cam 29
In order to ensure high responsiveness at the time of cam switching while driving the engine valve 13 to open and close the engine valve 13, a preceding hydraulic pressure supply region R <b> 2 that supplies hydraulic pressure to the cam switching type variable valve mechanism 50 in advance.
Then, it is determined which of the control regions R3 is in which the high-speed cam 31 drives the engine valve 13 to open and close.

As a result of the processing in step S302, when it is determined that the operation area of the internal combustion engine 1 is in the control area R1, the CPU 72 proceeds to the processing in step S303.
As the process of step S303, the CPU 72 sets the hydraulic pressure target value Pot as the constant hydraulic pressure set value Pou. The hydraulic pressure target value Pot is a control target value when controlling the opening amount of the OCV 33. The constant oil pressure set value Pou is used for lubricating the sliding portion of the cam switching type variable valve mechanism 50 and for maintaining the fluidity in the oil passages 39, 67, 68 reaching the hydraulic chamber 66. This is preset as a hydraulic pressure required to secure oil.

If it is determined in step S302 that the vehicle is in the preceding hydraulic pressure supply region R2, the CPU 7
2 shifts to the processing of step S304. In this step S304, the CPU 72 sets the hydraulic pressure target value Pot
Is set as the preceding hydraulic pressure set value Pop. This preceding hydraulic pressure set value P
op is the pressure at which the pressure of the lubricating oil in the hydraulic chamber 66 (FIGS. 3 and 4) of the cam switching type variable valve mechanism 50 is required to operate the lock mechanism, that is, the hydraulic piston 59 is attached to the coil spring 65. Rocker arm 25 moves against the power
Is set to a value slightly lower than the pressure required for restricting the sliding of the movable cam follower 54 with respect to.

After ending the processing in step S303 or S304, the CPU 72 proceeds to step S303.
The process proceeds to 306. In this step S306, the CPU 72 reads the oil pressure Pvt in the lubricating oil passage 39 detected by the oil pressure sensor 34,
Stored in 3.

As the processing of the subsequent step S307, the CPU
72 calculates the difference between the detected oil pressure Pvt and the target oil pressure value Pot as the difference Δ. Then, the CPU 72 adds a product of the difference Δ and the feedback coefficient K to the current duty command value IOCVduty as a new duty command value IOCVd as the process of step S308.
uty. The feedback coefficient K is a positive constant, and the current oil pressure Pvt is smoothly and promptly set to the oil pressure target value P.
It is set so that it can converge to ot. When the internal combustion engine 1 is started, the duty command value IOCVd
uty is a value corresponding to a duty ratio of 0%.

Thus, duty command value IOCVdut
After determining y, the CPU 72 proceeds to the process of step S309, and outputs the duty command value IOCVduty determined in the process of step S308 to the drive circuit 83 of the OCV 33. The drive circuit 83 controls the OCV 33 based on the duty command value IOCVduty. Thereby, the amount of lubricating oil supplied to the cam switching type variable valve mechanism 50 via the OCV 33 is adjusted. Thereafter, the CPU 72 once ends the processing of this routine.

On the other hand, as a result of the processing in step S302, when it is determined that the area is in the control area R3, the CPU 72 shifts to the processing in step S305. This step S308
The CPU 72 executes the processing of the duty command value IOCV
The duty is set to a value corresponding to a duty ratio of 100% or a duty ratio close thereto.

Thereafter, the process of the CPU 72 shifts to the aforementioned step S309, and outputs a duty command value IOCVduty corresponding to a duty ratio of 100% or a duty ratio close thereto to the drive circuit 83 of the OCV 33 to the drive circuit 83. I do. The drive circuit 83 controls the OCV 33 based on the duty command value IOCVduty. In this case, the opening between the first port 40 and the second port 41 of the OCV 33 is maximized, and the lubricating oil passage 39
, A large amount of lubricating oil is supplied. Thereafter, the CPU 72 once ends the processing of this routine.

The control routine described above is summarized as follows. When the operation region of the internal combustion engine is the control region R1, a constant hydraulic pressure set value Pou, which is a hydraulic pressure necessary for lubricating the sliding contact portion between the rocker arm 25 and the rocker shaft 24 and ensuring fluidity in the lubricating oil passage, is set to: In the case of the preceding hydraulic range R2, the preceding hydraulic set value Pop, which is slightly lower than the hydraulic pressure required for operating the lock mechanism, is set to the target hydraulic pressure Pot.
And The hydraulic pressure target value Pot set in this way is compared with the detected actual hydraulic pressure Pvt in the lubricating oil passage 38,
When the detected hydraulic pressure Pvt is higher than the target value Pot, the opening of the OCV 33 is reduced, and the actual hydraulic pressure Pvt is reduced. On the other hand, when the actual oil pressure Pvt is lower, O
The opening of the CV 33 is increased, and the actual hydraulic pressure Pvt is increased. In this way, feedback control is performed so that the actual oil pressure Pvt matches the target oil pressure value Pot.

As a result, in the control region R1, a small amount of lubricating oil is supplied, and the lubrication of the lubricating portion and the fluidity of the lubricating oil passage are maintained. However, since the amount of lubricating oil supplied at this time is small, the lock mechanism does not operate, and the engine valve 13 is opened and closed by the low speed cam 29.
Further, in the preceding hydraulic pressure supply region R2, the preceding hydraulic pressure is supplied to improve the responsiveness at the time of switching. Also in this case, the pressure of the supplied lubricating oil is insufficient for the operation of the lock mechanism, and the state in which the engine valve 13 is driven to open and close by the low-speed cam 29 is maintained. These regions R1, R2
Then, the opening of the OCV 33 is feedback-controlled based on the detected actual oil pressure Pvt, so that the lubricating oil passage 3
9 can always be at a desired pressure.

In the case of the control region R3, the opening between the first port 40 and the second port 41 of the OCV 33 is maximum,
Alternatively, the opening amount is set to a value close to that, and a large amount of lubricating oil is supplied to the cylinder oil passage 39. And
As the hydraulic pressure in the hydraulic chamber 66 increases, the lock mechanism is operated. That is, the hydraulic piston 59 moves against the urging force of the coil spring 65, and restricts the sliding of the movable cam follower 54 with respect to the rocker arm 25 in the mode illustrated in FIG. Thereby, the high-speed cam 31
The movable cam follower 54 which is pressed by the high-speed cam 31 swings integrally with the rocker arm 25, and the engine valve 13 is also opened and closed by the high-speed cam 31. At the time of transition from the preceding hydraulic pressure supply region R2 to the control region R3, the pressure in the hydraulic chamber 66 has been increased in advance to the preceding hydraulic pressure Pop. Therefore, it is possible to reduce the time from shifting to the control region R3 to increasing the oil pressure in the hydraulic chamber 66 to the oil pressure required for operating the lock mechanism.

According to the present embodiment described above, the first
In addition to the above effects of the embodiment, the following effects can be obtained. (6) Detecting the pressure of the lubricating oil in the oil passage connected to the cam switching type variable valve mechanism 50, and controlling the OCV 33 based on the detected pressure, allows more appropriate oil pressure control to be performed on the cam switching type variable valve mechanism. 50.

The above embodiment can be implemented by changing the configuration as described below. In the present embodiment, the preceding hydraulic pressure set value Pop is fixed, but may be changed so as to correct the value according to the temperature state of the internal combustion engine 1 as in the first embodiment. According to this configuration, it is possible to ensure the highest possible responsiveness over the entire temperature range while preventing the malfunction of the cam switching type variable valve mechanism 50 from occurring.

In the present embodiment, the control in the control region R1 and the control in the preceding hydraulic pressure supply region R2 are performed together. However, if at least one of these controls is performed, the first (1) and (4) described in the embodiment, or the above (1) to (4).
An effect similar to the effect of (3) can be obtained.

In this embodiment, the description has been given of the cam switching type variable valve mechanism for switching between two kinds of cams, that is, a low speed cam and a high speed cam. However, for example, two or more movable cam followers are provided. The hydraulic circuit and the control device according to the present embodiment can also be applied to a cam switching type variable valve mechanism that switches between three or more types of cams for low speed, medium speed, and high speed. . However, in this case, it is necessary to provide an OCV capable of independently controlling the hydraulic pressure and a separate lubricating oil supply path for the lock mechanism of each movable follower.

[0118] The present invention is not limited to the cam switching type variable valve mechanism in which the cam for opening / closing the engine valve is switched by restricting / allowing the sliding of the movable cam follower as in the present embodiment. Switching type variable valve mechanism, for example, FIG.
9 and a plurality of rocker arms oscillating corresponding to a plurality of types of cams as shown in FIG. 30, and a cam for opening and closing an engine valve by connecting (locking) and separating (unlocking) these rocker arms. The hydraulic circuit and the control device according to the present embodiment can also be applied to a cam switching type variable valve mechanism of a switching type. (Third Embodiment) Next, a third embodiment of the present invention will be described.

This embodiment is suitable for use in a variable valve apparatus having a cam-switching type variable valve mechanism provided with two series of movable cam followers independently controlled by one rocker shaft. is there.

Here, the same reference numerals are given to the same or corresponding elements as those in each of the above embodiments, and the duplicated description thereof will be omitted, and different parts will be mainly described. The variable valve mechanism 50 of the variable valve apparatus according to the present embodiment is of a type in which a cam for opening and closing an engine valve is switched in three stages. The cam switching type variable valve mechanism 50 includes a roller follower 52 In addition, two movable cam followers 54 that slide independently of each other, and separate locking mechanisms corresponding to the movable cam followers 54 are provided. FIG. 17 shows a front sectional structure of the cam switching type variable valve mechanism 50 according to the present embodiment, and FIG. 18 shows a planar sectional structure of the same mechanism 50 and its peripheral portion.

As shown in FIG. 18, the camshaft 20 is provided with three types of cams, a low speed cam 29, a medium speed cam 30, and a high speed cam 31, for each cylinder. The cam switching type variable valve mechanism 50 according to the present embodiment has a structure in which these three cams 29 to 31 can be selectively switched.

That is, as shown in FIG. 17, a roller follower 52 which can contact the low-speed cam 29 is provided at the center of the upper surface of the rocker arm 25 constituting the cam switching type variable valve mechanism 50. Roller Follower 5
Guide holes 53 (FIG. 18) are formed on both sides of 2, respectively, and a movable follower 54 is slidably inserted into each of the guide holes 53. One of the movable followers 54 can contact the medium speed cam 30 and the other can contact the high speed cam 31. Each of the movable followers 54 is provided with a lock mechanism for restricting or releasing the sliding of the movable follower cam 54 in the rocker arm 25 in the same manner as in the first embodiment.

Next, the hydraulic circuit of the variable valve apparatus according to the present embodiment will be described with reference to FIG. In addition,
Although FIG. 19 shows only one of the systems on the intake side and the exhaust side, the system on the side not shown has almost the same configuration.

As described above, the camshaft 20 is provided with three cams for each cylinder. These low-speed cams 29, medium-speed cams 30, and high-speed cams 3
In order of 1, the cam profile is formed such that at least one of the opening / closing period and the lift amount of the engine valve driven to open / close by the cams is increased. The cams are arranged in the order of high speed 31, low speed 29 and medium speed 30 in the case of the leftmost cylinder in FIG. 19, and medium speed 30 and low speed in the case of the cylinder adjacent to the right. 29, and 31 for high speed, and each adjacent cylinder is symmetric in the drawing. In addition, such an arrangement configuration is adopted because the hydraulic pressure supply path of the lock mechanism corresponding to the medium speed cam 30 or the high speed cam 31 of the adjacent cam switching type variable valve mechanism 50 is shared, and the configuration of the hydraulic circuit is simplified. To do that. With such a cam arrangement, the cam switching type variable valve mechanism 50
The lock mechanism has a configuration in which the medium speed engine and the high speed engine are provided symmetrically for each adjacent cylinder.

In the center of the oil passage 68 formed inside the rocker shaft 24 on which the rocker arm 25 is mounted, at the position where each rocker arm 25 is mounted, a cylindrical shape having substantially the same cross-sectional shape as the oil passage 68 is provided. The partition member 90 is fitted. This partition member 90 allows the oil passage 68
Are divided into five spaces 68a to 68e.

On the other hand, the oil passage 37 through which the lubricating oil pressurized and discharged from the oil pump 32 flows is provided with a medium-speed OCV 33a for operating each of the medium-speed lock mechanisms and a high-speed OCV 33a for operating each of the high-speed lock mechanisms. And connected to. These OCVs 33a and 33b have the same structure as the OCV 33 exemplified in the first embodiment. Then, similarly to the first embodiment, these OCVs
Drain passages 38a, 38b for returning lubricating oil to the oil pan 69 and cylinder oil passages 39a, 39b for supplying lubricating oil to the cam switching type variable valve mechanism 50 are connected to 33a, 33b, respectively. ing. The cylinder oil passages 39a and 39b extend to respective bearings of the rocker shaft 24 inside the cylinder head 3, and
The rocker shaft 24 is connected to the oil passage 68. However, the high-speed cylinder oil passage 39a and the medium-speed cylinder oil passage 39b are separated from the partitioned oil passages 68a to 68e.
And are formed alternately from the leftmost bearing portion in FIG. That is, of the oil passages 68 a to 68 e partitioned by the partition member 90, the oil passages 68 a and 68 e
Reference numerals c and 68e are connected to a high-speed cylinder oil passage 39a to form a high-speed rocker shaft oil passage. The oil passages 68b and 68d are cylinder oil passages 3 for medium speed.
9b and is a medium speed rocker shaft oil passage. Thus, each cam switching type variable valve mechanism 50
The lock mechanisms corresponding to the high-speed cam 31 and the medium-speed cam 30 in FIG.
From the lubricating oil as the working oil.

In this embodiment, the partition member 90 is provided with a small-diameter communication hole 91 penetrating in the axial direction of the rocker shaft 24 as shown in FIG. 20A is a plan view of the partition member 90, FIG. 20B is a side sectional view of the member 90, FIG. 20C is a perspective view of the member 90, and FIG. FIG. 4 is a cross-sectional view of the rocker shaft provided with a member. The communication hole 91 formed in the partition member 90 has a circular cross section, and connects adjacent ones of the rocker shaft oil passages 68a to 68e partitioned by the partition member 90. With this communication hole 91, when lubricating oil is supplied to one of the high-speed cylinder oil passage 39a and the medium-speed cylinder oil passage 39b, a small amount of lubricating oil leaks to the other. The leaked lubricating oil is used for lubricating the sliding contact portion of the lock mechanism at the leak destination and for maintaining the fluidity of the lubricating oil inside the cylinder oil passage and rocker shaft oil passage on the side where lubricating oil is not supplied. Is done. Therefore, the diameter of the communication hole 91 is set to a sufficient amount of lubricating oil for these purposes, that is, the first and second lubricating oils.
The lubricating oil corresponding to the hydraulic pressure supplied in control region R1 in the embodiment is set to leak. In the case of the present embodiment, the diameter of the communication hole 91 is about 1 mm.

By providing the communication hole 91 in the partition member 90, lubricating oil is supplied to only one of the lock mechanisms, and lubrication of the sliding portion of the other lock mechanism is performed. The lubricating oil required to ensure the fluidity of the lubricating oil in the oil passage can be supplied. Therefore, in the first or second embodiment, the control region R1 (see FIG.
In the present embodiment, the control in 0) is performed by using the OCV 33a,
The lubrication of the sliding portion and the fluidity of the lubricating oil in the oil passage can always be ensured by merely performing the operation on either one of the lubricating portions 33b. In each of the above-described embodiments, when the control in the preceding hydraulic pressure supply region R2 (FIG. 10) for supplying the preceding hydraulic pressure is not performed before the operation of the lock mechanism, one of the OCVs 33a and 33b is locked. A simple directional control valve that simply switches the supply of lubricating oil to and the discharge of lubricating oil from the same mechanism,
The hydraulic pressure can be constantly supplied to both lock mechanisms.

According to the present embodiment described above, the following effects can be obtained. By supplying lubricating oil to one of the lock mechanisms for high speed and medium speed, a small amount of lubricating oil can be supplied to the oil passage of the other lock mechanism. The lubricating oil thus supplied maintains lubrication of the sliding portion of the lock mechanism even when the lock mechanism is not operating. Further, since the fluidity of the lubricating oil in the oil passage is maintained, the responsiveness at the time of operating the lock mechanism can be improved.

The above embodiment can be implemented by changing its configuration as follows. As shown in FIG. 21, a groove 92 may be formed on the outer peripheral surface of the partition member 90, and the lubricating oil may leak through the groove 92 instead of the communication hole 91. 21A is a plan view of the partition member 90, and FIG.
FIG. 21B is a side sectional view of the member 90, and FIG. 21C is a perspective view of the member 90.

Also, as shown in FIG. 22, a hole or hole 93 orthogonal to the axial direction of the rocker shaft 24 is formed at the position where the partition member 90 of the rocker shaft 24 is attached, and communicates with the hole or hole 93. The partition member 90 having the hole 91 or the groove may be fitted from the side. FIG. 22 shows the partition member 9 attached to the rocker shaft 24.
0 shows an attachment mode.

Also, as in the above embodiment, the oil passage 6
23 is not divided along the longitudinal direction of the rocker shaft 24, but by inserting a plate-shaped partition member 90a as shown in FIG.
The oil passage 6 formed in the rocker shaft 24 as shown in FIG.
8 by inserting a tubular partition member 90b therein.
It may be divided into two oil passages 68f and 68g. Even in this case, the communication hole 91 is formed in the section member 90 that partitions each oil passage.
The same effect can be obtained by forming.

Further, as shown in FIG. 23 (c), two oil passages 68h and 68i are formed inside the rocker shaft 24 in parallel with the axis thereof, and the two oil passages 68h and 68i are provided for the respective lock mechanisms. You can also. Also in this case, the same effect as that of the present embodiment can be obtained by forming the communication hole 91 that connects the oil passages 68h and 68i.

In this embodiment, the description has been given of the cam switching type variable valve mechanism for switching between the three types of cams, that is, the low speed cam, the medium speed cam, and the high speed cam. The hydraulic circuit and the control device according to the present embodiment can also be applied to a cam switching type variable valve mechanism including the movable cam follower for switching four or more types of cams.

[0135] The present invention is not limited to the cam switching type variable valve mechanism of the type in which the cam for opening and closing the engine valve is switched by restricting / allowing the sliding of the movable cam follower as in the present embodiment. Switching type variable valve mechanism, for example, FIG.
9 and a plurality of rocker arms oscillating corresponding to a plurality of types of cams as shown in FIG. 30, and a cam for opening and closing an engine valve by connecting (locking) and separating (unlocking) these rocker arms. The hydraulic circuit and the control device according to the present embodiment can also be applied to a cam switching type variable valve mechanism of a switching type.

(Fourth Embodiment) Next, a fourth embodiment of the present invention will be described. This embodiment is different from the third embodiment only in the partition member for partitioning the oil passage formed in the rocker shaft. The configuration of the cam switching type variable valve mechanism and the like is the same as that of the third embodiment. This is the same as that of the embodiment. Therefore, the same reference numerals are given to the same or corresponding elements as those of the above-described embodiments, and the description thereof will not be repeated, and different parts will be mainly described.

FIG. 24 shows a hydraulic circuit of the variable valve apparatus according to the present embodiment, a part of the rocker shaft 24, a cam switching type variable valve mechanism 50, and the like. The rocker shaft 24 has an oil passage 68 having a circular cross section.
Are formed. A partition member 95 made of a helically twisted plate is fitted into the oil passage 68, and divides the oil passage 68 into two oil passages 68a and 68b. Of these, the oil passage 68a is connected to the high-speed cam 31.
The high-speed rocker shaft oil passage for supplying lubricating oil to the lock mechanism corresponding to
It is a medium-speed rocker shaft oil passage for supplying lubricating oil to the lock mechanism corresponding to. Rocker shaft 2
The oil passage 38a connected to the high-speed OCV 33a and the medium-speed OC
An oil passage 38b connected to V33b is open. The high-speed rocker shaft oil passage 68a and the medium-speed rocker shaft oil passage 68b in the rocker shaft 24
They are connected to oil passages 38a and 38b, respectively, via a high-speed lubricating oil supply hole 97a and a medium-speed lubricating oil supply hole 97b formed from the outer periphery of the rocker shaft 24. Therefore, each of the rocker shaft oil passages 68a and 68b can receive supply of lubricating oil through these oil passages 38a and 38b.

On the other hand, two openings 98a and 98b are formed in the rocker shaft 24 at the sliding contact with the rocker arm 25. These two openings 98a and 98b are opened in the same direction of the rocker shaft 24, and by adjusting the torsion interval of the partition member 95, the high-speed rocker shaft oil passage 6 is formed.
8a and the medium speed rocker shaft oil passage 68b. The cam switching type variable valve mechanism 50 is connected to an oil passage 67a connected to a hydraulic chamber 66a of a lock mechanism corresponding to the high speed cam 31, and to a hydraulic chamber 66b of a lock mechanism corresponding to the medium speed cam 30. An oil passage 67b is formed. The oil passages 67a and 67b communicate with the oil passages 68a and 68b formed in the rocker shaft 24 by the openings 98a and 98b.

The high-speed rocker shaft oil passage and the medium-speed rocker shaft oil passage are connected to each other by the rocker shaft 24, as in the examples shown in FIGS. 23A to 23C or the present embodiment. When formed in parallel along the axis, only one supply port for supplying lubricating oil to the rocker shaft oil passage may be provided for each series of lock mechanisms. Therefore, for example, the bearing portion 963
The lubricating oil passage formed therein can be more simplified than that of the third embodiment. However, when each rocker shaft oil passage is formed so as to be parallel to the axis of the rocker shaft 24 as in the example shown in FIGS.
Openings for supplying lubricating oil to the respective lock mechanisms must be provided in different directions. The fact that the openings are provided in different directions means that the rocker arm 24
This means that the structure of the cam-switching type variable valve mechanism 50 is complicated, for example, the configuration of the oil passage formed therein is complicated, and the arrangement of the lock mechanism is restricted.

In this respect, in this embodiment, the number of lubricating oil supply ports to the rocker shaft oil passages 68a and 68b is reduced by employing the spiral partition member 95, and the oil in the bearing 96 is reduced. The structure of the passage is simplified, and the opening 67a (9) formed in the sliding contact portion with the rocker arm 25 is formed.
8a) and 67b (98b) can be in the same direction. Therefore, the structure of the cam switching type variable valve mechanism 50 can be simplified in the mode shown in FIG.

As described above, according to the present embodiment, the following effects can be obtained. The lubricating oil supply passage can be simplified by reducing the number of lubricating oil supply ports to the rocker shaft oil passage, and the lubricating oil is supplied to the cam switching type variable valve mechanism 50. Openings can be provided in the same direction. As a result, the structure of the cam switching type variable valve mechanism 50 can be simplified.

The present embodiment can be implemented by changing its configuration as follows. The partition member 95 may be provided with a communication hole for communicating each rocker shaft oil passage as in the third embodiment. According to the configuration, the effect shown in the third embodiment can be obtained similarly.

Depending on the structure of the cam switching type variable valve mechanism 50, for example, the arrangement of the lock mechanism, it may be better to provide the openings in different directions. In such a case, the position of the opening can be optimized by partitioning the rocker shaft oil passage by the partition member 95 and adjusting the twist interval of the partition member 95 appropriately.

Further, the present invention is not limited to the cam switching type variable valve mechanism in which the cam for opening and closing the engine valve is switched by restricting / allowing the sliding of the movable cam follower as in the present embodiment. , A plurality of rocker arms swinging corresponding to a plurality of types of cams as shown in FIGS. 29 and 30, and connecting (locking) / separating (unlocking) these rocker arms. By doing so, the hydraulic circuit and the control device according to the present embodiment can be applied to a cam switching type variable valve mechanism that switches a cam that opens and closes an engine valve.

(Fifth Embodiment) Next, a fifth embodiment of the present invention will be described. First, regarding the overall configuration of the variable valve apparatus according to the present embodiment,
This will be described with reference to FIG.

The variable valve apparatus according to the present embodiment includes:
A variable valve mechanism, such as the cam switching type variable valve apparatus 50, in which a cam for opening and closing an engine valve is selectively switched to thereby vary a working angle and a lift amount of the cam, a camshaft, and an internal combustion engine And a variable valve mechanism of a type in which the opening / closing timing of the valve is made variable by making the rotation phase with the output shaft variable. Hereinafter, for convenience, the latter variable valve mechanism is referred to as a “phase displacement type variable valve mechanism”.

The cylinder head 3 of the internal combustion engine rotatably supports an intake camshaft 20i and an exhaust camshaft 20e. At the tip of the intake side camshaft 20i, an intake side cam pulley 21i is provided so as to be integrally rotatable. The intake camshaft 20i has:
As in the first embodiment, two types of cams, low speed 29 and high speed 31, are provided for each cylinder of the internal combustion engine. A rocker shaft 24 is disposed below the intake side camshaft 20i in the drawing, and both the intake side camshaft 20i and the rocker shaft 24 are supported by a bearing 96. This rocker shaft 2
A cam-switching type variable valve mechanism 50, which is constructed around a rocker arm 25 similar to that of the first embodiment for each cylinder, is attached to each cylinder 4. It is configured to be driven to open and close via a valve mechanism 50.

On the other hand, all the cams 90 having the same shape are provided on the exhaust side camshaft 20e. These cams 9
Numeral 0 directly drives a valve lifter of an exhaust valve (not shown) to open and close. A phase displacement type variable valve mechanism 120 is mounted at the tip of the exhaust side camshaft 20e. The exhaust camshaft 20e is connected to the exhaust cam pulley 2 via the phase displacement type variable valve mechanism 120.
1e is mounted so as to be relatively rotatable.

The intake-side cam pulley 20i and the exhaust-side cam pulley 20e are connected via a timing belt 22 to a crankshaft (not shown) serving as an output shaft of the internal combustion engine.
, And rotates with the operation of the internal combustion engine.

Next, the phase displacement type variable valve mechanism 120 provided on the exhaust side camshaft 20e will be described with reference to FIG. This phase displacement type variable valve mechanism 120
Are the exhaust-side cam pulley 21e and the exhaust-side camshaft 20.
By relatively rotating e, the rotation phase between a crankshaft (not shown) and the exhaust-side camshaft 20e is changed, and the opening / closing timing of the exhaust valve 13e is made variable.

At the tip of the exhaust side camshaft 20e, a substantially cylindrical internal rotor 121 is provided with a center bolt 122.
Are mounted so as to be able to rotate together. A plurality of (three in FIG. 26) vanes 123 are formed on the outer peripheral portion of the inner rotor 121 so as to project in the radial direction of the exhaust-side camshaft 20e.

A housing 124 is provided so as to cover the outer periphery of the vane 123. On the inner peripheral side surface of the housing 124, the shaft 2 is located at a predetermined distance in the circumferential direction of the exhaust side camshaft 20e.
Three protruding portions 126 protruding toward the axis 0e are formed. The portion between adjacent protrusions 126 is recess 1
25, and the vane 12 is provided in the recess 125.
3 are provided.

Further, the front end surfaces of the inner rotor 121 and the housing 124 are covered with a front cover. The housing 124, the exhaust side cam pulley 21e (FIG. 25), and the front cover are fastened together by four mounting bolts 127 so as to be integrally rotatable.

The distal end of each vane 123 and the inner peripheral side surface of the concave portion 125, and the distal end of each protruding portion 126 and the outer peripheral side surface of the internal rotor 122 are in sliding contact with each other.
0e and the internal rotor 121, and the exhaust side cam pulley 21
e and the housing 124 are relatively rotatable about the same axis.

Further, inside the phase displacement type variable valve mechanism 120, the front cover, the exhaust side cam pulley 21e, the inner peripheral wall of each recess 125 of the housing 124 and the inner rotor 1 are provided.
Three spaces are formed which are surrounded by the outer peripheral side surface of the outer peripheral surface 22. These spaces are further divided by vanes 123
Are divided into two spaces 128, 129. Of these spaces 128 and 129, the space 129 formed in the rotation direction of the exhaust-side camshaft 20 e with respect to the vane 123.
Is a retard side hydraulic chamber, and the space 128 formed on the opposite side is an advance side hydraulic chamber.

A coil spring 130 is provided in the advance side hydraulic chamber 128 so as to be sandwiched between the vane 122 and the projection 126. By the urging force of the coil spring 130, the inner rotor 121 is urged to rotate relatively to the housing 124 in the rotation direction of the exhaust camshaft 20e. That is,
The exhaust side camshaft 20e is provided with an exhaust side cam pulley 21e.
Is applied to the shaft 20e so as to rotate in the rotation direction of the shaft 20e. The biasing force of the coil spring 130 is set to be sufficiently larger than the reaction force acting in the counter rotation direction of the exhaust side camshaft 20e because the cam drives the opening and closing of the exhaust valve 13e when the exhaust side camshaft 20e rotates. Therefore, each hydraulic chamber 128, 12
9 is empty, as shown in FIG.
1 is an exhaust camshaft 2 with respect to the housing 124.
0e is located at the position where it is relatively rotated in the rotation direction. Hereinafter, this position is referred to as a “most advanced position”, and conversely, a position that is relatively rotated in the most counter-rotating direction is referred to as a “most retarded position”.

The advance hydraulic passage 128 and the retard hydraulic passage 129 are connected to an advance oil passage 131 and a retard oil passage 132 (FIG. 25), respectively. These oil passages 131 and 132 are formed in the internal rotor 122, the exhaust cam pulley 21e, the exhaust cam shaft 20e, and the like, and open to the bearing 96 of the exhaust cam shaft 20e. These oil passages 131, 132
The lubricating oil can be supplied to the respective hydraulic chambers 128 and 129 via the through holes or the lubricating oil can be discharged from the respective hydraulic chambers 128 and 129.

The phase displacement type variable valve mechanism 120 operates based on the hydraulic control in the hydraulic chambers 128 and 129 to change the opening / closing timing of the exhaust valve 13e. Hereinafter, an operation mode of the phase displacement type variable valve mechanism 120 will be described.

When the opening / closing timing of the exhaust valve 13e is delayed (hereinafter referred to as "retarding"), the advance-side hydraulic chamber 12
The lubricating oil in the inside 8 is discharged and the lubricating oil is supplied into the retard side hydraulic chamber 129. Thus, the force acting on the side of the vane 123 on the side of the retard hydraulic chamber 129 is applied to the advance hydraulic chamber 128.
Relative to the side. As a result, the internal rotor 122 receives a force in the anti-rotation direction of the exhaust-side camshaft 20e, and is rotated relative to the housing 124. Therefore, the retard side camshaft 20e relatively rotates with respect to the retard side cam pulley 21e in the anti-rotation direction of the shaft 20e, and the opening and closing timing of the exhaust valve 13e is delayed.

On the other hand, when the opening / closing timing of the exhaust valve 13 e is advanced (hereinafter referred to as “advance”), the advance hydraulic chamber 1
The lubricating oil is supplied to the inside 28 and the lubricating oil is discharged from the retard side hydraulic chamber 129. In this way, the force acting on the side surface of the vane 123 on the advance hydraulic pressure chamber 128 side is relatively increased with respect to the retard hydraulic pressure chamber 129 side. Similarly to the above, the exhaust-side camshaft 20e is relatively rotated with respect to the exhaust-side cam pulley 21e in the rotation direction of the shaft 20e,
The opening / closing timing of the exhaust valve 13e is advanced.

Further, when maintaining the opening / closing timing of the exhaust valve 13e, the forces acting on both side surfaces of the vane 123 are balanced by controlling the hydraulic pressure in the hydraulic chambers 128 and 129. In this way, the relative rotation between the exhaust-side camshaft 20e and the exhaust-side cam pulley 21e is restricted, and the opening / closing timing of the exhaust valve 13e is fixed.

Next, the configuration of the hydraulic circuit of the variable valve operating apparatus according to the present embodiment will be described with reference to FIG.
The oil pump 32 sucks the lubricating oil in the oil pan 69 and pressurizes and discharges the lubricating oil supply passage 36 formed in the cylinder block 2 and the cylinder head 3. This lubricating oil supply path 36 is connected to the OCV 133 for the phase displacement type variable valve mechanism 120.

The OCV 133 is a four-port type hydraulic control valve, and is provided on the cylinder head 3. In addition to the lubricating oil supply passage 36, an advanced cylinder oil passage 134 connected to the advanced oil passage 131 at a bearing portion of the exhaust camshaft 20 e, and similarly connected to the retard oil passage 132. The drain oil passage 136 for returning lubricating oil to the retard cylinder oil passage 135 and the oil pan 69 is also connected. The OCV 133 is also controlled by an ECU (not shown).
The amount of lubricating oil supplied to or discharged from each of the cylinder oil passages 134 and 135 is made continuously variable, and the hydraulic chambers 128 and 129 of the phase displacement type variable valve mechanism 120 (FIG.
6) It is possible to adjust the oil pressure inside.

The advance-side cylinder oil passage 134 branches on the way, and the OCV 33 for the cam switching type variable valve mechanism 50 is provided.
Is also connected. The OCV 33 is a hydraulic control valve that continuously varies the amount of lubricating oil supplied to the cam-switching type variable valve mechanism 50 as in the above-described embodiments, and is controlled by the ECU. That is, in the present embodiment, the OCV 33 for the cam switching type variable valve mechanism 50 receives the supply of the lubricating oil when the lubricating oil is being supplied to the advance side cylinder oil passage 134.

Next, an example of a control mode of the cam switching type variable valve mechanism 50 and the phase displacement type variable valve mechanism 120 according to the present embodiment will be described. Cam switching type variable valve mechanism 5
The zero and phase displacement type variable valve mechanism 120 is driven and controlled in accordance with the operating state of the internal combustion engine, which is determined from the engine speed NE and the intake air amount Q. The engine speed NE and the intake air amount Q are detected by the crank angle sensor 9 and the air flow meter 19 (FIG. 1) as in the first embodiment. FIG. 27 shows a two-dimensional map based on the engine speed NE and the intake air amount Q, which is referred to in controlling the variable valve apparatus 50 and the phase displacement variable valve mechanism 120 in the present embodiment.

First, the control mode of the intake system will be described. The region R4 on the left side of the line L5 in FIG. 27 is a low rotation operation region in which the intake valve 13i is driven to open and close by the low speed cam 29. In this region R4, the OCV 33 is controlled so as to shut off the supply of lubricating oil to the cam switching type variable valve mechanism 50, or to supply only a very small amount of lubricating oil. In the region R5 between the line L5 and the line L6, the first and second embodiments relate to the cam switching type variable valve mechanism 50 while the intake valve 13i is opened and closed by the low speed cam 31. This is a preceding hydraulic pressure supply area for supplying the same preceding hydraulic pressure. In this region R5, the ECU
Controls the OCV 33 so that an appropriate preceding hydraulic pressure can be supplied to the cam switching type variable valve mechanism 50. On the other hand, a region R6 on the right side of the curve L6 is a high rotation operation region in which the intake valve 13i is driven to open and close by the high speed cam 31. In this region R6, the ECU supplies the lubricating oil to the cam switching type variable valve mechanism 50, and controls the OCV 33 to switch to the high speed cam 31.

Next, the control mode of the exhaust system will be described. The phase displacement type variable valve mechanism 120 is controlled so that the opening / closing timing of the exhaust valve 13e is variable only in the low-speed operation region R4. As shown in FIG.
The opening / closing timing of the exhaust valve 13e is set to be the most advanced near a curve L5 which is a boundary between the low-speed operation region R4 and the preceding hydraulic pressure supply region R5. In the preceding hydraulic supply region R5 and the high-speed operation region R6, the phase displacement type variable valve mechanism 12
0 is fixed to the most advanced position, and the opening / closing timing of the intake valve 13e is fixed to the most advanced position. That is, in the preceding hydraulic supply region R5 and the high-speed operation region R6 in which lubricating oil is supplied to the cam switching type variable valve mechanism 50, the hydraulic pressure is always supplied to the advance hydraulic chamber 128, This means that lubricating oil is also supplied to the OCV 33 for the cam switching type variable valve mechanism 50 via the advance side cylinder oil passage 134.

Incidentally, the cam switching type variable valve mechanism 50
Is to selectively switch a plurality of cams having different operating angles and lift amounts to change the time area of the engine valve (time integral of the lift amount of the engine valve). During a high-speed operation of the internal combustion engine in which the required intake air amount or exhaust air amount increases, the engine valve is opened and closed by a cam having a larger operating angle and a larger lift amount, thereby increasing the time area of the engine valve. Thus, the static pressure loss at the time of intake or exhaust is reduced, the amount of intake or exhaust is increased, and the maximum output of the internal combustion engine is improved. In addition, during low-speed operation of the internal combustion engine, the time required for one combustion step is relatively long, and accordingly, the time during which the engine valve is open is also long. If the time area of the engine valve is increased in such a state, the combustion gas is blown back from the exhaust side to the intake side, and the intake is hindered. Therefore, by opening and closing the engine valve with a cam having a smaller operating angle and a smaller lift amount, the time area of the engine valve is reduced, and the torque during low-speed operation is secured.

Further, the exhaust from the combustion chamber is performed at a higher pressure than the intake air based on the explosion of the air-fuel mixture. On the other hand, the intake air into the combustion chamber is performed by the differential pressure between the atmospheric pressure and the pressure in the cylinder, and therefore, only a lower pressure can be used as compared with the exhaust pressure. Therefore, since the effect of the expansion of the time area is more remarkable on the intake side than on the exhaust side, the cam switching type variable valve mechanism 50 is provided on the intake side as in the present embodiment. The benefits are great.

On the other hand, the phase displacement type variable valve mechanism 120
This is a mechanism in which the period during which the intake valve and the exhaust valve are simultaneously open, that is, the overlap period of the engine valve, is made variable by making the rotation phase of the camshaft variable.
One of the advantages of making the amount of overlap variable is that the amount of combustion gas generated in the previous combustion process remaining in the combustion chamber,
That is, the internal EGR amount can be adjusted. By making this internal EGR amount appropriate,
Pumping loss can be reduced and fuel efficiency can be improved. Further, the temperature at the time of combustion can be reduced, and generation of NOx can be suppressed. Such an effect can be obtained in the same manner regardless of whether the phase displacement type variable valve mechanism 120 is adopted on the intake side or the exhaust side. For this reason, the configuration provided on the exhaust side has a greater merit.

That is, particularly in the case of an internal combustion engine having a high compression ratio, if the lift amount of the engine valve is increased, interference between the upper end surface of the piston and the head of the engine valve becomes a problem. Therefore, a recess (valve recess) is formed on the upper end surface of the piston to avoid interference between the piston and the engine valve. Usually, there is a difference between the time when the piston is located at the top dead center and the time when the lift amount of the engine valve is maximized, so that the valve recess should be formed in consideration of the amount of interference between the time when the piston and the engine valve come closest. I just need. However, when both the cam switching type variable valve mechanism 50 and the phase displacement type variable valve mechanism 120 are provided on the intake side, the piston and the engine valve are most likely to be moved according to the operation of the phase displacement type variable valve mechanism 120. Since the approaching time changes, the amount of these interferences tends to increase. As a result, the valve recess becomes large, and the shape of the combustion chamber, especially the S / V ratio, deteriorates, leading to a decrease in combustion efficiency, an increase in heat loss, a decrease in knock limit, and the like, and consequently a decrease in performance and fuel efficiency of the internal combustion engine. It will be.

A cam switching type variable valve mechanism 5 is provided on the intake side.
When both 0 and the phase displacement type variable valve mechanism 120 are provided, the fluctuation of the cam driving torque generated when the cam is switched by the cam switching type variable valve mechanism 50 causes the operation of the phase displacement type variable valve mechanism 120 to operate. There is a concern that this will have an adverse effect. Therefore, by adopting a configuration in which the cam switching type variable valve mechanism 50 is employed on the intake side and the phase displacement type variable valve mechanism 120 is employed on the exhaust side as in the present embodiment, the above problems can be avoided appropriately. In addition, the performance of the internal combustion engine can be improved.

On the other hand, conventionally, when two types of variable valve mechanisms are provided and independently controlled as in the present embodiment, hydraulic paths for supplying lubrication to these variable valve mechanisms are completely separate. Has been adopted. Therefore, the total length of the hydraulic path is increased, and the configuration of the hydraulic path is also complicated, resulting in an increase in manufacturing steps and manufacturing costs. In addition, since it is necessary to supply lubricating oil to separate hydraulic paths, the amount of lubricating oil consumed by these variable valve mechanisms also increases. In this regard, in the present embodiment, the lubricating oil supply path to the phase displacement type variable valve mechanism 120 and the cam switching type variable valve mechanism 50 is provided in series, and the above-described control mode is adopted. As a result, the hydraulic path is simplified and the amount of oil consumed is reduced.

As described above, according to the present embodiment, the following effects can be obtained. By providing the hydraulic path of the cam switching type variable valve mechanism 50 and the hydraulic path of the phase displacement type variable valve mechanism 120 in series, the total length of the hydraulic path can be shortened, and the structure is simplified and consumption is reduced. The amount of oil can be reduced.
In addition, the simplification of the structure reduces the number of parts and the number of processing parts, and can reduce manufacturing costs and manufacturing steps.

Also, by using the cam switching type variable valve mechanism 50 on the intake side and the phase displacement type variable valve mechanism 120 on the exhaust side, the interference between the head of the engine valve and the upper end surface of the piston and the cam It is possible to further enhance the effect of improving the maximum output by the cam switching type variable valve mechanism 50 and the effect of improving the emission and fuel efficiency by the phase displacement type variable valve mechanism 120 while suitably avoiding the trouble caused by the fluctuation of the driving torque. become able to.

The above embodiment can be implemented by changing its configuration as follows. In the present embodiment, the OCV 33 for the cam switching type variable valve mechanism 50 is connected to the advance side cylinder oil passage 136. However, the OCV 33 may be connected to the retard side cylinder oil passage 135. . However, in such a configuration,
When the cam is switched, lubricating oil must be supplied to the retard side hydraulic chamber 129 of the phase displacement type variable valve mechanism 120, and the control mode needs to be changed accordingly.

The hydraulic circuit configuration of the present embodiment is different from the configuration in which the cam switching type variable valve mechanism 50 is on the intake side and the phase displacement type variable valve mechanism 120 is on the exhaust side. The present invention is also applicable to a configuration in which the variable valve operating mechanism 120 is used, the cam switching variable valve operating mechanism 50 is provided on the exhaust side, and both variable valve operating mechanisms are provided on the intake side.

OCV for cam switching type variable valve mechanism 50
33 for the phase-displacement type variable valve mechanism 120 on the discharge side
The configuration may be changed so as to connect V133. However, in such a configuration, it is necessary to change the control mode so as to control the phase displacement type variable valve mechanism 120 only when lubricating oil is supplied to the cam switching type variable valve mechanism 50. There is. Specifically, (a) the lock mechanism of the cam switching type variable valve mechanism 50 is supplied with hydraulic pressure to slide the movable follower 54 in the rocker arm 25, contrary to the above embodiments. The movable follower 54 in the rocker arm 25 is restricted from sliding by permitting the movement and cutting off the hydraulic pressure supply.

(B) The phase displacement type variable valve mechanism 120 is
When hydraulic pressure is supplied to the lock mechanism of the cam switching type variable valve mechanism 50, that is, when the rocker arm 2
It is assumed that the movable follower 54 is allowed to slide within 5 and is controlled only when the cam switching type variable valve mechanism 50 is oscillated by the low speed cam 29.

(C) When no hydraulic pressure is supplied to the variable phase valve mechanism 120, the camshaft 20
There is provided a mechanism for fixing the relative rotation phase between the motor and the cam pulley 21 to a predetermined phase. Under such conditions, the OCV 133 for the phase displacement type variable valve mechanism 120 is provided on the discharge side of the OCV 33 for the cam switching type variable valve mechanism 50.
Can be adopted.

Further, the present invention is not limited to the cam switching type variable valve mechanism in which the cam for opening and closing the engine valve is switched by restricting / allowing the sliding of the movable cam follower as in the present embodiment. , A plurality of rocker arms swinging corresponding to a plurality of types of cams as shown in FIGS. 29 and 30, and connecting (locking) / separating (unlocking) these rocker arms. By doing so, the hydraulic circuit and the control device according to the present embodiment can be applied to a cam switching type variable valve mechanism that switches a cam that opens and closes an engine valve.

・ Similarly, a phase displacement type variable valve mechanism 1
20 is not limited to the so-called vane type as in this embodiment, but may be changed to a phase displacement type variable valve mechanism of another type such as a helical gear type.

In addition, technical ideas other than the above-mentioned claims that can be understood from the above embodiments are described below together with their effects. (1) A variable valve actuating device having a cam switching type variable valve mechanism for selectively switching a cam for opening and closing an engine valve from a plurality of types of cams based on hydraulic pressure control of hydraulic fluid. The variable valve mechanism has two hydraulic pressure control mechanisms that are hydraulically controlled based on hydraulic fluids separately supplied through respective hydraulic fluid supply passages defined in the support shaft, and has three types of hydraulic control mechanisms. A cam for opening and closing the engine valve is selected from cams, and a partition means for partitioning the hydraulic fluid supply passage in the support shaft has a small diameter communicating with each of the other hydraulic fluid passages. A variable valve train having a communication hole.

According to this configuration, when the hydraulic fluid is supplied to one of the two hydraulic control mechanisms, the hydraulic fluid is also supplied to the other hydraulic control mechanism through the communication hole. It will be. By appropriately setting the diameter of the communication hole, a desired amount of hydraulic fluid can be supplied to another hydraulic pressure control mechanism. Using the supplied hydraulic fluid, lubrication of the sliding contact portion of the cam switching type variable valve mechanism and the like and fluidity of the hydraulic fluid in the hydraulic fluid passage can be maintained. Therefore, the responsiveness of the variable valve device can be improved and stabilized.

(2) In a variable valve apparatus having a cam switching type variable valve mechanism for selectively switching a cam for opening and closing an engine valve from a plurality of kinds of cams based on hydraulic pressure control of hydraulic fluid, The switching-type variable valve mechanism is hydraulically controlled based on hydraulic fluids supplied separately through respective hydraulic fluid supply passages defined in the support shaft.
A cam for opening and closing the engine valve from among three types of cams having three hydraulic pressure control mechanisms, wherein the partitioning means for partitioning the hydraulic fluid supply passage in the support shaft includes: A variable valve train that is spirally stretched in the axial direction of the shaft.

According to this configuration, the working fluid supply path formed in the support shaft for supplying the working fluid to the two hydraulic pressure control mechanisms is not parallel to the axis of the support shaft, but the axis of the support shaft. Is stretched so as to spiral around the. Therefore, by adjusting the torsion interval of the partition member, the direction of the position of the connection portion between the cam switching type variable valve mechanism and the hydraulic fluid supply passage can be freely set.

(3) A cam switching type variable valve mechanism for selectively switching a cam for opening and closing an engine valve from a plurality of types of cams based on hydraulic fluid pressure control, and based on hydraulic fluid pressure control A phase displacement type variable valve mechanism for varying the rotation phase between the engine output shaft and the camshaft; a first hydraulic pressure control valve for controlling an amount of hydraulic fluid supplied to the cam switching type variable valve mechanism; A second hydraulic pressure control valve for controlling an amount of hydraulic fluid supplied to the phase displacement type variable valve mechanism;
And the second hydraulic pressure control valve supplies the hydraulic fluid branch-supplied from one of the hydraulic fluid discharge sections to the corresponding variable valve mechanism.

According to this structure, it is possible to provide the hydraulic fluid supply path for the cam switching type variable valve mechanism and the hydraulic fluid supply path for the phase displacement type variable valve mechanism almost in series, Can be shortened. Therefore, it is possible to simplify the hydraulic fluid supply path and reduce the amount of consumed oil.

(4) The cam switching type variable valve mechanism is provided in a valve operating system on the engine intake side, and the phase displacement type variable valve operating mechanism is provided in a valve operating system on the engine exhaust side (3). 3. The variable valve apparatus according to claim 1.

According to this structure, the effect of improving the maximum output by the cam-switching type variable valve mechanism can be achieved while suitably avoiding the trouble caused by the interference between the head portion of the engine valve and the upper end surface of the piston and the fluctuation of the cam driving torque. In addition, the effect of improving emission and fuel efficiency by the phase displacement type variable valve mechanism can be further enhanced.

[0191]

According to the first aspect of the present invention, the amount of hydraulic fluid supplied to the cam switching type variable valve mechanism by the hydraulic pressure control valve can be continuously varied.
Therefore, the amount of the supplied hydraulic fluid can be finely adjusted according to the situation, and the variable valve operating device can be stabilized and the responsiveness can be improved.

According to the second aspect of the present invention, the cam switching time can be reduced, and the responsiveness of the variable valve operating device can be improved. Also,
According to the third aspect of the present invention, the cam switching time can be shortened, and the responsiveness of the variable valve apparatus can be improved.

According to the fourth aspect of the present invention, the cam switching type variable valve mechanism is suppressed as much as possible while preventing the malfunction of the cam switching type variable valve mechanism due to the pressure fluctuation of the working fluid. Responsiveness can be improved.

Further, according to the fifth aspect of the invention, it is possible to always secure the working fluid used for purposes other than the cam switching operation of the cam switching type variable valve mechanism, for example, lubrication. . Also, the fluidity of the hydraulic fluid in the hydraulic fluid passage used for supplying the hydraulic fluid to the cam switching type variable valve mechanism is always maintained, and the responsiveness of the mechanism can be improved. Become.

According to the sixth aspect of the present invention, it is possible to always supply an appropriate amount of the hydraulic fluid to be supplied except during the cam switching operation of the cam switching type variable valve mechanism. According to the invention of claim 7, since the pressure in the hydraulic fluid passage can be constantly grasped and the opening of the hydraulic fluid control valve can be feedback-controlled based on the pressure, a more appropriate amount of hydraulic fluid can be supplied. It can be supplied to the variable valve device.

Further, the invention described in claim 8 is characterized in that the hydraulic pressure of the working fluid supplied in advance prior to the cam switching operation of the cam switching type variable valve mechanism, or that the mechanism is not operated during the cam switching operation. The hydraulic pressure of the supplied working fluid can be made more appropriate.

According to the ninth aspect of the present invention, the hydraulic fluid supplied through the communication hole is used to lubricate a sliding contact portion of a cam switching type variable valve mechanism or the like, and to hydraulic fluid in a hydraulic fluid passage. Can maintain the liquidity of
The responsiveness of the variable valve device can be improved and stabilized.

According to the tenth aspect of the present invention,
The direction of the position of the connection between the cam switching type variable valve mechanism and the hydraulic fluid supply passage can be freely set.
According to the eleventh aspect of the present invention, the entire length of the hydraulic fluid supply path can be shortened, so that the configuration can be simplified and the amount of consumed oil can be reduced. In addition, the simplification of the configuration of the working fluid supply path reduces the number of parts and the number of processing parts, and can also reduce manufacturing costs and manufacturing steps.

According to the twelfth aspect of the present invention,
The effect of improving the maximum output by the cam switching type variable valve mechanism provided with the cam switching device and the effect of improving the emission and fuel efficiency by the phase displacement type variable valve mechanism while suitably avoiding the occurrence of malfunctions. Will be able to

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a configuration of an internal combustion engine provided with a variable valve operating device according to a first embodiment.

FIG. 2 is a plan view showing a planar structure of a cam switching type variable valve mechanism.

FIG. 3 is a sectional view showing the structure of a lock mechanism of the mechanism.

FIG. 4 is a sectional view showing the structure of the lock mechanism.

FIG. 5 is a perspective view showing the shape of a hydraulic piston.

FIG. 6 is a sectional view showing the structure of a hydraulic control valve.

FIG. 7 is a sectional view showing the structure of a hydraulic control valve.

FIG. 8 is a block diagram showing an electric configuration of a control system of the variable valve apparatus according to the first embodiment.

FIG. 9 is a flowchart showing a control procedure of the variable valve apparatus according to the embodiment.

FIG. 10 is a graph showing a relationship between an operation region of the internal combustion engine and a control region of the variable valve device of the embodiment.

FIG. 11 is a graph showing a relationship between a coolant temperature and a duty command value in a lock mechanism non-operating region.

FIG. 12 is a graph showing a relationship between a coolant temperature and a duty command value in a preceding hydraulic pressure supply region.

FIG. 13 is a graph showing a relationship between a cooling water temperature, an OCV opening, a viscosity of lubricating oil, and a leakage amount in a lock mechanism non-operating region.

FIG. 14 is a graph showing a relationship between an engine speed and a hydraulic pressure in a hydraulic chamber in a preceding hydraulic pressure supply region.

FIG. 15 is a schematic diagram showing a configuration of a hydraulic circuit and a control system of a variable valve operating apparatus according to a second embodiment.

FIG. 16 is a flowchart showing a control procedure of the variable valve operating device of the embodiment.

FIG. 17 is a sectional view showing a planar structure of a cam switching type variable valve mechanism according to a third embodiment.

FIG. 18 is a sectional view showing a front structure of the mechanism.

FIG. 19 is a schematic diagram showing a valve train of an internal combustion engine provided with a variable valve train according to a third embodiment and a hydraulic circuit configuration thereof.

FIG. 20 is a plan view, a cross-sectional view, and a perspective view showing a partition member employed in the apparatus and a mounting mode thereof.

FIG. 21 is a front view, a sectional view, and a perspective view showing a modification of the partition member.

FIG. 22 is a front view showing a modification of the partition member.
Side view.

FIG. 23 is a sectional view showing a modification of the partition member.

FIG. 24 is a schematic diagram illustrating a hydraulic circuit, a rocker shaft, and a peripheral configuration of a variable valve apparatus according to a fourth embodiment.

FIG. 25 is a schematic diagram showing a valve train of an internal combustion engine provided with the variable valve train according to the fifth embodiment.

FIG. 26 is a sectional view showing a configuration of a phase displacement type variable valve mechanism.

FIG. 27 is a graph showing a relationship between an operating state of the internal combustion engine and a control region of the variable valve operating device.

FIG. 28 is a sectional view showing a structural example of a conventional cam switching type variable valve mechanism.

FIG. 29 is a sectional view showing a structural example of a conventional cam switching type variable valve mechanism.

FIG. 30 is a schematic diagram showing a hydraulic circuit configuration of the same mechanism.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Internal combustion engine, 9 ... Crank angle sensor, 10 ... Electronic control unit (ECU), 13 ... Engine valve, 19 ... Air flow meter, 20 ... Camshaft, 21 ... Cam pulley, 23
... Crank pulley, 24 ... Rocker shaft, 25 ... Rocker arm, 26 ... Cooling water temperature sensor, 29 ... Low speed cam,
Reference numeral 30: Medium speed cam, 31: High speed cam, 33: Hydraulic control valve, 38: Drain passage, 39: Cylinder oil passage, 50
... Variable valve operating mechanism of cam switching type, 51 ... Arm, 53 ... Guide hole, 54 ... Movable cam follower, 58 ... Cylinder hole, 5
9: Hydraulic piston, 64: Spring receiving member, 65: Coil spring, 66: Hydraulic chamber, 67: Rocker arm oil passage, 68: Rocker shaft oil passage, 70: Microcomputer, 72: CPU, 83: Drive circuit, 90: Partition member, 91: communication hole, 92: groove, 120: phase displacement type variable valve mechanism, 121: internal rotor, 123: vane, 1
Reference numeral 24: housing, 128: advance hydraulic chamber, 129: retard hydraulic chamber, 131: advance oil passage, 132: retard oil passage, 133: hydraulic control valve, 134: advance cylinder oil passage 135, retard cylinder oil passage.

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Koichi Shimizu 1 Toyota Town, Toyota City, Aichi Prefecture Inside Toyota Motor Corporation (72) Inventor Hiromasa Suzuki 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Motor Corporation

Claims (12)

[Claims] A cam switching type variable valve mechanism for selectively switching a cam for opening and closing an engine valve from a plurality of types of cams based on hydraulic pressure control of a hydraulic fluid; and a cam switching type variable valve mechanism. And a hydraulic pressure control valve capable of continuously changing the amount of hydraulic fluid to be supplied. 2. The variable valve operating device according to claim 1, wherein the hydraulic fluid supplied to the cam switching type variable valve mechanism is increased to a predetermined hydraulic pressure prior to the cam switching operation by the cam switching variable valve mechanism. A variable valve actuating device, comprising: a preceding hydraulic pressure control means for controlling the hydraulic pressure control valve. 3. The advance hydraulic pressure control means increases pressure to the predetermined hydraulic pressure at a predetermined rotational speed lower than an engine rotational speed at which a cam switching operation by the cam switching type variable valve mechanism is performed. 3. The variable valve apparatus according to claim 2, wherein the variable valve apparatus controls a hydraulic pressure control valve. 4. The variable valve operating apparatus according to claim 2, wherein the preceding hydraulic pressure control means includes temperature correction means for correcting the predetermined hydraulic pressure to be increased in advance according to an engine temperature. 5. The variable valve operating device according to claim 1, wherein a predetermined amount is supplied to the cam switching variable valve mechanism in addition to a cam switching operation by the cam switching variable valve mechanism. A variable valve actuating device comprising a constant hydraulic pressure control means for controlling the hydraulic pressure control valve so as to constantly supply the hydraulic fluid. 6. The variable valve operating apparatus according to claim 5, wherein said constant hydraulic pressure control means further comprises a temperature correction means for correcting the amount of the constantly supplied hydraulic fluid according to an engine temperature. 7. The variable valve operating device according to claim 1, wherein the hydraulic pressure detecting unit detects a hydraulic pressure of the hydraulic fluid supplied to the cam switching type variable valve mechanism, and the hydraulic pressure detecting unit detects the hydraulic pressure. The variable valve according to any one of claims 1 to 6, further comprising feedback control means for performing feedback control of an opening amount of the hydraulic pressure control valve so that the hydraulic pressure to be converged to a target predetermined hydraulic pressure. apparatus. 8. The cam control device according to claim 1, wherein the feedback control means is configured to supply a pre-pressurized hydraulic fluid to the cam switching type variable valve mechanism in advance of a cam switching operation by the cam switching type variable valve mechanism. In addition to the switching operation of the cam by the switching type variable valve mechanism, at least one of the constant hydraulic pressures set to constantly supply a predetermined amount of the hydraulic fluid to the cam switching type variable valve mechanism is set to the predetermined target. 8. The feedback control of the opening of the hydraulic pressure control valve as a hydraulic pressure.
3. The variable valve apparatus according to claim 1. 9. The cam-switching type variable valve mechanism includes two fluids whose hydraulic pressures are controlled based on hydraulic fluids separately supplied through respective hydraulic fluid supply passages defined in a support shaft thereof. A cam that has a pressure control mechanism and that opens and closes the engine valve from among three types of cams; and a partitioning unit that partitions the hydraulic fluid supply passage within the support shaft, The variable valve apparatus according to any one of claims 1 to 8, wherein a communication hole having a small diameter communicating between the hydraulic fluid supply passages is formed. 10. The cam-switching type variable valve mechanism includes two fluids whose hydraulic pressures are controlled based on hydraulic fluids separately supplied through respective hydraulic fluid supply passages defined in a support shaft thereof. A cam that has a pressure control mechanism to open and close the engine valve from among three types of cams; and a partitioning unit that partitions the working fluid supply passage within the support shaft, The variable valve train according to any one of claims 1 to 8, wherein the variable valve train is spirally stretched in an axial direction. 11. A variable displacement valve according to claim 1, wherein the rotational phase of an engine output shaft and a camshaft is varied based on hydraulic pressure control of a hydraulic fluid. A mechanism for controlling the amount of hydraulic fluid supplied to the phase-variable variable valve mechanism, wherein the hydraulic control valve discharges hydraulic fluid from the phase-variable hydraulic control valve. A hydraulic fluid branched and supplied from a section to the cam switching type variable valve mechanism. 12. The variable valve mechanism according to claim 11, wherein said variable valve mechanism is provided in a valve system on the engine intake side, and said variable valve mechanism is provided in a valve system on the engine exhaust side. The variable valve train according to any one of the preceding claims.