JP2000110528A - Variable valve system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent increasing of a program development process and a memory capacity, and ensure engine startability and stability with refuge running capable, always by a fixed fail-safe process so as to be capable of coping with that even when a trouble is caused in a valve lift amount adjusting mechanism of an internal combustion engine. SOLUTION: A stable position of an intake can shaft is unified in a position as shown by a drawing (A) even in any trouble of an electric system and hydraulic system. Accordingly, a fixed fail-safe process can always cope with the trouble, increasing of a program development process and a memory capacity can be prevented. A condition that a valve lift amount of an intake valve is minimum further with closed timing Ci shifted to a side of advance angle is provided even at any trouble time, as shown in the drawing (A). In this way, the intake valve can be closed earlier, to enhance startability of an engine. Accordingly, refuge running can be made by early starting after a trouble.

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 used in an internal combustion engine, and more particularly to a variable valve operating device using a three-dimensional cam whose cam profile continuously changes in the direction of the rotation axis.

[0002]

2. Description of the Related Art Conventionally, in an intake valve or an exhaust valve, a valve lift amount when the internal combustion engine is rotating at a low speed and a valve lift amount when the internal combustion engine is at a high speed are determined by using a low-speed cam and a high-speed cam. There is known a variable valve actuating device provided with a valve lift adjusting mechanism which is realized by switching according to Japanese Patent Application Laid-Open No. 8-177434. Further, in this conventional technique, the phase of the camshaft is also adjusted by providing a valve timing adjusting mechanism.

In this prior art, when either the valve lift adjustment mechanism or the valve timing adjustment mechanism fails, the valve lift adjustment mechanism is switched to the low speed cam side, and the valve timing adjustment mechanism is switched to the camshaft. Is on the retard side. This prevents the intake valve from interfering with the piston and the exhaust valve in the event of a failure.

[0004]

However, in the failure of the valve lift adjusting mechanism, it is not certain which of the low-speed cam and the high-speed cam is functioning.
Therefore, even in the case of performing the fail-safe process for driving the internal combustion engine to perform the limp-home run, the failure state in which the low-speed cam is functioning and the failure state in which the high-speed cam is functioning are handled. Fail-safe processing must be prepared in advance. This leads to an increase in program development processes and an increase in the memory capacity for storing these programs.

[0005] Further, depending on the failure state, for example, when the high-speed cam is functioning and fails, the engine startability and rotational stability may be deteriorated, making it difficult to perform limp-home running.

According to the present invention, even if the valve lift adjusting mechanism fails, it can always be dealt with by a constant fail-safe process to prevent a program development process and an increase in memory capacity. It is another object of the present invention to make it possible to perform limp-home running while further ensuring engine startability and stability.

[0007]

According to a first aspect of the present invention, there is provided a variable valve apparatus provided on a camshaft of an internal combustion engine, wherein a three-dimensional cam having a cam profile continuously changing in a rotation axis direction is provided. A lift variable actuator that continuously varies a valve lift by the three-dimensional cam by moving a cam shaft in an axial direction; and a hydraulic pressure that generates a hydraulic pressure for operating the lift variable actuator. By controlling the supply of the hydraulic pressure from the hydraulic pressure generation source to the lift amount variable actuator,
A hydraulic pressure control valve for adjusting a movement position of the camshaft, wherein the camshaft is controlled by the hydraulic pressure when the supply control of the hydraulic pressure by the hydraulic fluid control valve is stopped. A stable position where the camshaft is directed when the hydraulic pressure from the hydraulic pressure generation source is not supplied to the lift variable actuator.

When a three-dimensional cam is used for the valve lift adjusting mechanism of the variable valve operating device, the valve lift is determined by the contact position of the valve side structure with respect to the cam surface of the three-dimensional cam. However, when a failure occurs in which the hydraulic pressure is not supplied from the hydraulic pressure generation source, the camshaft side moves in the axial direction due to the balance between the contact pressure from the valve side and other forces. Finally, the camshaft is settled to a stable position, that is, a position where a mechanically stable state is obtained. That is, the contact position due to the configuration on the valve side is stabilized at a specific valve lift amount.

When the hydraulic pressure is supplied but the supply control of the hydraulic pressure by the hydraulic control valve is stopped, the hydraulic pressure from the hydraulic control valve is shifted to a stable position corresponding to the stop of the supply control. Move the camshaft. For this reason, the contact position by the configuration on the valve side is stabilized at a certain specific valve lift amount.

The variable valve operating device is designed so that the stable position in the case of the failure in which the supply of the hydraulic pressure is stopped is the same as the stable position in the case of the failure in which the supply control of the hydraulic fluid control valve is stopped. It is possible to do.

By designing in this way,
Regardless of which failure occurs, the camshaft position and the valve lift amount are the same, so that one fail-safe process can always be used. Therefore, it is possible to prevent an increase in the program development process and the memory capacity.

[0012] The variable valve apparatus according to the second aspect is the first aspect.
In the configuration described above, the stable position is a position where the valve lift is minimized. As described above, by setting both the stable position in the case of the failure in which the supply of the hydraulic pressure is stopped and the stable position in the case of the failure in which the supply control of the hydraulic fluid control valve is stopped, the position where the valve lift is minimized. The operation and effect according to claim 1 are produced. Further, since this stable position is a position where the valve lift is minimized, in the case of an intake valve, rotation stability and engine startability can be secured by reducing valve overlap and advancing the closing timing. , Evacuation traveling can be enabled. In the case of an exhaust valve, rotation stability can be ensured by reducing valve overlap and delaying the opening timing, so that limp-home traveling can be performed.

According to a third aspect of the present invention, there is provided a variable valve operating apparatus.
Or the lift amount variable actuator moves the cam nose position of the three-dimensional cam in an advance direction or a retard direction when moving the cam shaft in the axial direction. Wherein the stable position is a position where the cam nose position is the most retarded.

As described above, when the phase of the cam nose position of the three-dimensional cam moves in the advance direction or the retard direction when the lift amount variable actuator moves the cam shaft in the axial direction. The stable position may be a position where the cam nose position is the most retarded. As a result, in addition to the functions and effects of the first and second aspects, especially in the case of an intake valve, the valve overlap is reduced, so that the rotational stability is improved. Particularly in the case of an exhaust valve, the opening timing is retarded, so that rotational stability is enhanced.

According to a fourth aspect of the present invention, there is provided a variable valve operating apparatus according to the first aspect.
Or the lift amount variable actuator moves the cam nose position of the three-dimensional cam in an advance direction or a retard direction when moving the cam shaft in the axial direction. Wherein the stable position is a position where the cam nose position is the most advanced angle.

As described above, when the phase of the cam nose position of the three-dimensional cam moves in the advance direction or in the retard direction when the lift amount variable actuator moves the cam shaft in the axial direction. The stable position may be a position where the cam nose position is at the most advanced angle. Thus, in addition to the effects of the first and second aspects, especially in the case of an intake valve, the closing timing is advanced, so that the engine startability is enhanced. In the case of an exhaust valve, the rotation stability is improved because the valve overlap is reduced.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS [First Embodiment] FIG. 1 is a structural explanatory view schematically showing a variable valve operating device.

The gasoline engine (hereinafter simply referred to as "engine") 11 is an in-line four-cylinder in-vehicle gasoline engine. The engine 11 includes a cylinder block 13 provided with a reciprocating piston 12, and an oil pan 13a provided below the cylinder block 13.
And a cylinder head 14 provided above the cylinder block 13.

A crankshaft 15 as an output shaft is rotatably supported below the engine 11, and a piston 12 is connected to the crankshaft 15 via a connecting rod 16. The reciprocating motion of the piston 12 is converted into rotation of the crankshaft 15 by the connecting rod 16. A combustion chamber 17 is provided above the piston 12, and an exhaust passage 18 and an intake passage 19 are connected to the combustion chamber 17. The exhaust passage 18 and the combustion chamber 17 are communicated and blocked by an exhaust valve 20, and the intake passage 19 and the combustion chamber 1 are separated.
7 is communicated and shut off by the intake valve 21.

On the other hand, an exhaust camshaft 22 and an intake camshaft 23 are provided in the cylinder head 14 in parallel and also in parallel with the crankshaft 15. The exhaust camshaft 22 is supported on the cylinder head 14 so as to be rotatable but immovable in the axial direction. On the other hand, the intake camshaft 23 is supported on the cylinder head 14 so as to be rotatable and movable in the axial direction.

At one end of the exhaust camshaft 22, a timing pulley 24a is provided. A lift variable actuator 25 having a timing pulley 25a is provided at one end of the intake camshaft 23 on the same side as the timing pulley 24a. The lift amount variable actuator 25 changes the cam profile of a three-dimensional cam described later by moving the intake camshaft 23 in the axial direction, and adjusts the lift amount and the valve opening period of the intake valve 21.

These timing pulleys 24a, 25a
Is connected via a timing belt 26 to a timing pulley 15a attached to the crankshaft 15. The rotation of the crankshaft 15 is transmitted to the exhaust camshaft 22 and the intake camshaft 23 via the timing belt 26, so that the exhaust camshaft 22 and the intake camshaft 23 rotate in synchronization with the rotation of the crankshaft 15. I do.

The exhaust camshaft 22 has an exhaust valve 2
An exhaust cam 27 is provided at the upper end of the exhaust cam 27 to come into contact with the valve lifter. On the other hand, the intake camshaft 23 is provided with an intake cam 28 that is in contact with the upper end of the intake valve 21 via a valve lifter. With this configuration, when the exhaust camshaft 22 rotates, the exhaust valve 20 is driven to open and close according to the profile of the exhaust cam 27, and when the intake camshaft 23 rotates, the intake cam 2
The intake valve 21 is opened and closed according to the profile 8.

Here, the cam profile of the exhaust cam 27 is constant with respect to the axial direction of the exhaust camshaft 22, but the cam profile of the intake cam 28 is, as shown in FIG. Is continuously changing. That is, the intake cam 28 is configured as a three-dimensional cam.

For this reason, the intake camshaft 23 is indicated by an arrow A.
Moving in the direction, the intake valve 21 by the intake cam 28
, The valve lift continuously increases gradually. At the same time, the opening timing of the intake valve 21 is advanced and the closing timing is delayed, so that the valve opening period is continuously and gradually increased. Further, when the intake camshaft 23 moves in the direction opposite to the direction of the arrow A, the valve lift of the intake valve 21 by the intake cam 28 continuously decreases gradually. At the same time, the opening timing of the intake valve 21 is retarded and the closing timing is advanced, so that the valve opening period is continuously shortened gradually.

As described above, by moving the intake camshaft 23 in the axial direction, the valve opening period of the intake valve 21 and the adjustment of the valve lift can be continuously adjusted.

Next, the lift variable actuator 25,
An oil supply structure for driving the lift amount variable actuator 25 by hydraulic pressure will be described with reference to FIG. As shown in FIG.
5 has a timing pulley 25a. The timing pulley 25a has a cylindrical portion 151 through which the intake camshaft 23 penetrates, and a disk portion 15 protruding from the outer peripheral surface of the cylindrical portion 151.
2 and a plurality of external teeth 1 provided on the outer peripheral surface of the disc 152
53. The cylindrical portion 151 of the timing pulley 25a is rotatably supported by the bearing portion 14b of the cylinder head 14. And the intake camshaft 2
3 penetrates the cylindrical portion 151 so that it can move in the axial direction.

A cover 1 is provided on the timing pulley 25a so as to cover the end of the intake camshaft 23.
54 are fixed by bolts 155. Cover 1
At a position corresponding to the end of the intake camshaft 23 on the inner peripheral surface of the piston 54, a plurality of internal teeth 157 are provided along the circumferential direction. The internal teeth 157 are formed as flat teeth extending linearly in the axial direction of the intake camshaft 23.

On the other hand, at the tip of the intake camshaft 23,
The ring gear 162 formed in a cylindrical shape is fixed by the hollow bolt 158 and the pin 159. Outer teeth 163 meshing with inner teeth 157 of the cover 154 are provided on the outer peripheral surface of the ring gear 162. The external teeth 163 are formed as flat teeth extending linearly in the axial direction of the intake camshaft 23. That is, the ring gear 162
Is rotated in the axial direction of the intake camshaft 23 with respect to the timing pulley 25a,
3 and can be moved.

In the lift amount variable actuator 25 configured as described above, when the crankshaft 15 rotates by the driving of the engine 11 and the rotation is transmitted to the timing pulley 25a via the timing belt 26, the timing pulley 25a Intake camshaft 2
3 rotates together. With the rotation of the intake camshaft 23, the intake valve 21 is opened and closed.

When the ring gear 162 moves toward the timing pulley 25a (to the right in the drawing) by a mechanism to be described later, the intake camshaft 23 also moves integrally (to the right in the drawing: the direction of arrow A). . As a result, the cam profile of the intake cam 28 with which the cam follower 21a of the intake valve 21 abuts changes continuously in the direction in which the lift amount is large and the valve opening period is long. That is, the opening timing of the intake valve 21 is advanced, and the closing timing is delayed.

When the ring gear 162 moves to the cover 154 side (left side in the drawing: FIG. 3 shows a state where the ring gear 162 has already moved to the left limit), the intake camshaft 23 is also integrated. (Left of drawing:
(The direction opposite to arrow A). As a result, the intake cam 2 against which the cam follower 21a of the intake valve 21 contacts
The cam profile of No. 8 continuously changes in such a manner that the lift amount is small and the valve opening period is short. That is, the opening timing of the intake valve 21 is retarded, and the closing timing is advanced. Next, the structure of the lift amount variable actuator 25 for hydraulically controlling the movement of the ring gear 162 will be described.

The inside of the cover 154 includes a ring gear 162.
The outer peripheral surface of the disc-shaped ring portion 162a is in close contact with the inner peripheral surface of the cover 154 so as to be slidable in the axial direction.
It is partitioned into a high lift side hydraulic chamber 165 and a low lift side hydraulic chamber 166. Inside the intake camshaft 23, the high lift control oil passage 1 connected to the high lift side hydraulic chamber 165 and the low lift side hydraulic chamber 166, respectively.
67 and low lift control oil passage 168.

The high lift control oil passage 167 is connected to the hollow bolt 1
It communicates with the high lift side hydraulic chamber 165 through the inside of the cylinder 58, and is connected to an oil control valve (corresponding to a hydraulic fluid control valve) 170 through the inside of the cylinder head 14. Also, low lift control oil passage 1
Numeral 68 communicates with the low lift side hydraulic chamber 166 through an oil passage 172 in the cylindrical portion 151 of the timing pulley 25a, and is connected to an oil control valve 170 through the inside of the cylinder head 14.

On the other hand, a supply passage 128 and a discharge passage 130 are connected to the oil control valve 170. The supply passage 128 is connected to the oil pan 13a via the oil pump P, and the discharge passage 130
Is directly connected to the oil pan 13a.

As shown in FIG. 3, the oil control valve 170 has a casing 116,
6, the first supply / discharge port 118, the second supply / discharge port 12
0, a first discharge port 122, a second discharge port 124, and a supply port 126 are provided. The oil passage P1 is connected to the first supply / discharge port 118, and the second supply / discharge port 12
The oil passage P2 is connected to 0. In addition, supply port 1
26 is connected to a supply passage 128 through which hydraulic oil is supplied from an oil pump P, and a first discharge port 122 and a second
The discharge port 130 is connected to the discharge port 124 for discharging hydraulic oil to the oil pan 13a. A spool 138 having four valve portions 132 and urged in opposite directions by a coil spring 134 and an electromagnetic solenoid 136 is provided in the casing 116.

When the electromagnetic solenoid 136 is in the demagnetized state, the spool 138
The first supply / discharge port 118 communicates with the first discharge port 122, and the second supply / discharge port 120 communicates with the supply port 126 due to the urging force of the casing 116. I do. In this state, the operating oil in the oil pan 13a is supplied to the supply passage 128, the oil control valve 170, the oil passage P2, the low lift control oil passage 16
8 and the oil passage 172 through the low lift side hydraulic chamber 16.
6. The hydraulic oil in the high lift side hydraulic chamber 165 is returned to the oil pan 13a via the high lift control oil passage 167, the oil passage P1, the oil control valve 170, and the discharge passage 130. As a result, the ring gear 162 moves together with the intake cam shaft
Move in the opposite direction. As a result, the low lift side of the intake cam 28 comes into contact with the cam follower 21a of the intake valve 21, so that the lift amount of the intake valve 21 is reduced and the valve opening period is shortened. FIG. 3 shows the state of the minimum lift amount. At this time, the relationship with the lift amount on the exhaust valve 20 side is such that there is no valve overlap as shown in FIG.

On the other hand, when the electromagnetic solenoid 136 is excited, the spool 138 is disposed on the other end side (left side in FIG. 3) of the casing 116 against the urging force of the coil spring 134, and the second supply / discharge port 120 Communicate with the second discharge port 124, and the first supply / discharge port 118 communicates with the supply port 126. In this state, the oil pan 13
The hydraulic oil in a is supplied to the supply passage 128, the oil control valve 170, the oil passage P1, and the high lift control oil passage 167.
Is supplied to the high lift side hydraulic chamber 165 via the Also,
The hydraulic oil in the low lift side hydraulic chamber 166 is
2. The oil is returned to the oil pan 13a via the low lift control oil passage 168, the oil passage P2, the oil control valve 170, and the discharge passage 130. As a result, the ring gear 16
2 moves together with the intake camshaft 23 in the direction of arrow A in the figure. As a result, the high lift side of the intake cam 28 comes into contact with the cam follower 21a of the intake valve 21, so that the lift amount of the intake valve 21 increases and the valve opening period becomes longer. FIG. 4 shows the state of the maximum lift amount. At this time, the relationship with the lift amount on the exhaust valve 20 side is shown in FIG.
As shown in (1), the valve overlap is in the maximum secured state.

Further, when the power supply to the electromagnetic solenoid 136 is controlled and the spool 138 is positioned at the center of the casing 116 as shown in FIG. 5, the first supply / discharge port 118 and the second supply / discharge port 120 are closed, The movement of the hydraulic oil through the supply / discharge ports 118 and 120 is prohibited. In this state, supply and discharge of hydraulic oil to and from the high lift side hydraulic chamber 165 and the low lift side hydraulic chamber 166 are not performed.
High lift side hydraulic chamber 165 and low lift side hydraulic chamber 166
Is filled with hydraulic oil, and the position of the ring gear 162 is fixed. Therefore, there is no change in the profile of the intake cam 28 with respect to the cam follower 21a, and the lift amount and the valve opening period of the intake valve 21 are maintained.

A lift amount adjusting ECU (ECU: electronic control unit) 180 that controls power supply to the oil control valve 170 is provided with a CPU 1 as shown in FIG.
82, a ROM 183, a RAM 184, a backup RAM 185, and the like.

The ROM 183 is a memory that stores various control programs and data such as maps and tables that are referred to when executing the various control programs. The CPU 182 executes necessary arithmetic processing based on various control programs and data stored in the ROM 183. Further, the RAM 184 is a memory for temporarily storing the result of calculation by the CPU 182, data input from each sensor, and the like, and the backup RAM 185 is a nonvolatile memory for storing data to be stored when the engine 11 is stopped. Then, the CPU 182, the ROM 183,
The RAM 184 and the backup RAM 185 are connected to each other via a bus 186, and are also connected to an external input circuit 187 and an external output circuit 188.

The external input circuit 187 further includes an engine 11 such as an intake pressure sensor and a throttle sensor (not shown).
Sensors for detecting the operation state of the crankshaft, the crank-side electromagnetic pickup 190, and the shaft position sensor 1
94 is connected. Here, the crank-side electromagnetic pickup 190 detects the rotation phase and the number of rotations of the crankshaft 15, and the shaft position sensor 194 detects the axial position of the intake camshaft 23. An oil control valve 170 is connected to the external output circuit 188.

Here, the ECU 180 controls the intake valve 2
No. 1 valve characteristic control is performed. That is, the ECU 18
0 indicates that it is necessary to adjust the lift amount and the valve opening period of the intake valve 21 in order to bring the engine 11 into an appropriate operation state based on detection signals from various sensors that detect the operation state of the engine 11. , The power supply of the oil control valve 170 is controlled. For example, a target shaft position (corresponding to a target lift amount) of the intake camshaft 23 is obtained from a map using the engine speed detected from the crank-side electromagnetic pickup 190 and the engine load obtained from an intake pressure sensor or the like as parameters. Then, the lift amount variable actuator 25 is driven so that the intake camshaft 23 is at the target shaft position.

At the time of this power supply control, the ECU 180 inputs a detection signal from the shaft position sensor 194, and obtains a shaft position of the intake camshaft 23 in the axial direction based on the detection signal. Then, the oil control valve 17 is adjusted so as to match the target lift amount of the intake valve 21 and the target shaft position for achieving the valve opening period.
The feedback control for the lift amount variable actuator 25 is performed via the control signal 0.

Here, in the above configuration, the ECU 1
It is assumed that a failure occurs in which a current cannot be supplied to the electromagnetic solenoid 136 due to a disconnection of a conductor from the oil control valve 170 to the electromagnetic solenoid 136 of the oil control valve 170.

In this case, since the electromagnetic solenoid 136 cannot push the spool 138 against the coil spring 134, the oil control valve 170
Is in the state shown in FIG.

Therefore, in the intake camshaft 23, the position where the profile with the smallest valve lift in the profile of the intake cam 28 abuts the cam follower 21a is the stable position. Therefore, in the case where the power supply to the electromagnetic solenoid 136 is stopped, as shown in FIG. 6 (A), the state is such that the valve lift is the minimum and there is no valve overlap.

Next, due to the failure of the oil pump P or the rupture of an oil passage from the oil pump P to the variable lift actuator 25 via the oil control valve 170, no hydraulic pressure is supplied to the variable lift actuator 25 at all. Let us consider a case where a failure occurs.

In this case, no hydraulic pressure is applied to the ring gear 162 from the high lift side hydraulic chamber 165 or the low lift side hydraulic chamber 166, and the ring gear 162 cannot restrain the position of the intake camshaft 23 in the axial direction.

However, since the cam surface of the intake cam 28 is tapered, the contact pressure with the cam follower 21a causes the intake camshaft 23 to receive a force moving in the direction opposite to the arrow A shown in the figure from the cam follower 21a.

Therefore, the ring gear 162 receives the moving force from the intake camshaft 23 and moves together with the intake camshaft 23 in the direction opposite to the arrow A. Therefore, the intake camshaft 23 is settled in the state shown in FIG. 3 as a stable position. That is, in the case where the hydraulic pressure does not act on the lift variable actuator 25,
As shown in (A), the state is such that there is no valve overlap with the minimum lift amount.

As described above, the stable position of the intake camshaft 23 is the same in both the case where the power supply to the electromagnetic solenoid 136 is stopped and the case where the hydraulic pressure does not act on the lift variable actuator 25.

According to the first embodiment described above, the following effects can be obtained. (I). As described above, in the present variable valve apparatus, the stable position of the intake camshaft 23 is unified at a specific opening / closing timing with a minimum valve lift amount in any failure. Therefore, no matter which failure occurs, the valve lift amount and the opening / closing timing are the same, and can always be dealt with by one fail-safe process.
The program development process stored in the ROM 183 and the ROM 1
83 can be prevented from increasing.

(B). Further, as shown in FIG. 6 (A), in any failure, since there is no valve overlap, stable rotation of the engine 11 can be ensured. In any failure, the intake valve 21 can be closed at the earliest by setting the valve lift to the minimum position, and the startability of the engine 11 is improved. Therefore, evacuation traveling can be enabled.

Second Embodiment A second embodiment will be described with reference to FIGS. 1 to 5 used in the first embodiment.

In the first embodiment, the ring gear 1 of the lift variable actuator 25 shown in FIGS.
The 62 outer teeth 163 and the inner teeth 157 of the cover 154 were both flat teeth. Therefore, the ring gear 162 can move with the intake camshaft 23 in the axial direction of the intake camshaft 23 without rotating with respect to the timing pulley 25a.

However, in the second embodiment, unlike such a configuration, the outer teeth 163 of the ring gear 162 and the inner teeth 157 of the cover 154 are both oblique teeth. Here, the intake camshaft 23 is a lift amount variable actuator 25.
It is assumed that the external teeth 163 and the internal teeth 157 are both spline-shaped with left-hand threads, as viewed from the side. Other configurations are the same as the first embodiment.

As a result, when the electromagnetic solenoid 136 is in the demagnetized state, the ring gear 162 moves together with the intake camshaft 23 in the direction opposite to the arrow A as shown in FIG. As a result, the low lift side of the intake cam 28 comes into contact with the cam follower 21a of the intake valve 21, so that the lift amount of the intake valve 21 is reduced and the valve opening period is shortened. Further, the rotation phase of the intake camshaft 23 as viewed from the lift variable actuator 25 becomes the most advanced side due to the action of the beveled outer teeth 163 and the inner teeth 157. Therefore, at this time, as shown in FIG. 7A, the lift state of the intake valve 21 with respect to the exhaust valve 20 is such that the valve lift amount is the minimum but the valve overlap is the maximum.

On the other hand, when the electromagnetic solenoid 136 is excited, the ring gear 162 moves together with the intake camshaft 23 in the direction of arrow A as shown in FIG. As a result, the high lift side of the intake cam 28 comes into contact with the cam follower 21a of the intake valve 21, so that the lift amount of the intake valve 21 increases and the valve opening period becomes longer. Further, the rotation phase of the intake camshaft 23 is the most retarded as viewed from the lift amount variable actuator 25 by the action of the beveled outer teeth 163 and the inner teeth 157. Therefore, at this time, the lift state of the intake valve 21 is
As shown in FIG. 7B, the valve lift amount is the maximum, but there is no valve overlap.

Here, in the above configuration, the ECU 1
It is assumed that a failure occurs in which a current cannot be supplied to the electromagnetic solenoid 136 due to a disconnection of a conductor from the oil control valve 170 to the electromagnetic solenoid 136 of the oil control valve 170.

In this case, the electromagnetic solenoid 136 cannot push the spool 138 against the coil spring 134, so that the oil control valve 17
0 is the state shown in FIG.

For this reason, in the intake camshaft 23, the position where the profile with the smallest valve lift amount in the profile of the intake cam 28 abuts on the cam follower 21a is the stable position. Therefore, in the case of a failure in which the power supply to the electromagnetic solenoid 136 is stopped, as shown in FIG. 7A, the valve lift amount is the minimum, and the closing timing Ci is shifted to the most advanced side.

Next, due to the failure of the oil pump P or the rupture of the oil path from the oil pump P to the variable lift actuator 25 via the oil control valve 170, no hydraulic pressure is supplied to the variable lift actuator 25 at all. Let us consider a case where a failure occurs.

In this case, no oil pressure is applied to the ring gear 162 from the high lift side hydraulic chamber 165 or the low lift side hydraulic chamber 166, and the ring gear 162 cannot restrain the position of the intake camshaft 23 in the axial direction.

However, since the cam surface of the intake cam 28 has a tapered shape, the contact pressure with the cam follower 21a causes the intake camshaft 23 to receive a force moving in the direction opposite to the arrow A shown in the figure from the cam follower 21a.

Further, the internal teeth 157 of the cover 154 and the external teeth 163 of the ring gear 162 are left-handed bevels. For this reason, the intake camshaft 23 covers the force to move in the direction of the arrow A shown in the figure based on the friction that the intake camshaft 23 receives from the cam follower 21a on the journal bearing or the intake cam 28 provided on the cylinder head 14 (not shown). 154 from internal teeth 157.

Of the two opposing forces, the angle of the cam surface of the intake cam 28 and the internal teeth 1 are adjusted so that the force for moving the intake camshaft 23 in the direction opposite to the arrow A in the drawing is increased.
57 and the angles of the external teeth 163 are designed.

Therefore, the ring gear 162 receives a force from the intake camshaft 23 and moves together with the intake camshaft 23 in the direction opposite to the arrow A. Therefore, the intake camshaft 23 is settled in the state shown in FIG. 3 as a stable position. That is, the lift variable actuator 25
As shown in FIG. 7A, when the oil pressure does not act on the valve, the valve lift amount is the minimum and the closing timing C
i is in the state shifted to the most advanced side.

As described above, the stable position of the intake camshaft 23 is the same regardless of the failure in which the power supply to the electromagnetic solenoid 136 is stopped and the failure in which the hydraulic pressure does not act on the lift variable actuator 25.

According to the second embodiment described above, the following effects can be obtained. (I). As described above, in this variable valve apparatus, the stable position of the intake camshaft 23 is unified to the position shown in FIG. Therefore, the same effect as (a) of the first embodiment is obtained.

(B). In addition, as shown in FIG. 7A, in any failure, the valve lift of the intake valve 21 is minimum and the closing timing Ci is shifted to the most advanced side. Thus, the intake valve 21 can be closed earlier than in the first embodiment, and the startability of the engine 11 is improved. Therefore, it is possible to start the vehicle early after the failure and perform the limp-home running.

Third Embodiment FIGS. 8 and 9 show a third embodiment.
1 shows a variable valve operating device. In the third embodiment, the lift variable actuator 25 differs from the second embodiment.
Is designed so that the balance between the force in the direction of arrow A and the force in the opposite direction described in the second embodiment is reversed when a failure occurs in which no hydraulic pressure is supplied to the motor. different. That is, the angle of the cam surface of the intake cam 28, the angle of the internal teeth 157, and the angle of the external teeth 163 are set so that the force for moving the intake camshaft 23 in the direction of arrow A in the drawing becomes larger among the two opposing forces. Is designed.

Further, an oil passage which is supplied from the oil control valve 170 to the high lift side hydraulic chamber 165 and the low lift side hydraulic chamber 166 of the lift amount variable actuator 25 is mounted in reverse to the case of the second embodiment. It is a point. That is, the oil passage P1 from the supply / discharge port 118
1 is connected to the low lift side hydraulic chamber 166, and the supply / discharge port 1
The oil passage P12 from 20 is connected to the high lift side hydraulic chamber 165.

The external teeth 163 of the ring gear 162,
The internal teeth 157 of the cover 154 are both beveled teeth and have a left-hand threaded spline shape as in the second embodiment.

As a result, when the electromagnetic solenoid 136 is in the demagnetized state, as shown in FIG. 8, the oil pressure is supplied from the supply / discharge port 120 to the high lift side hydraulic chamber 165, and the ring gear 162 is shown together with the intake camshaft 23. Move in the direction of arrow A. As a result, the high lift side of the intake cam 28 comes into contact with the cam follower 21a of the intake valve 21, so that the lift amount of the intake valve 21 increases,
The valve opening period becomes longer. Furthermore, the outer teeth 163 and the inner teeth 1 of the bevel teeth
57, the lift amount variable actuator 25
As seen from the above, the rotational phase of the intake camshaft 23 is the most retarded. Therefore, at this time, the lift amount of the intake valve 21 is the maximum with respect to the exhaust valve 20 side, as in the state shown in FIG. 7B, but there is no valve overlap. .

On the other hand, when the electromagnetic solenoid 136 is excited, the ring gear 162 moves together with the intake camshaft 23 in the direction opposite to the arrow A as shown in FIG. As a result, the low lift side of the intake cam 28 comes into contact with the cam follower 21a of the intake valve 21, so that the lift amount of the intake valve 21 is reduced and the valve opening period is shortened. Further, the rotation phase of the intake camshaft 23 as viewed from the lift variable actuator 25 becomes the most advanced side due to the action of the beveled outer teeth 163 and the inner teeth 157. Therefore, at this time, the lift amount of the intake valve 21 is the minimum with respect to the exhaust valve 20 side, as in the state shown in FIG. I have.

Here, in the above configuration, the ECU 1
It is assumed that a failure occurs in which a current cannot be supplied to the electromagnetic solenoid 136 due to a disconnection of a conductor from the oil control valve 170 to the electromagnetic solenoid 136 of the oil control valve 170.

In this case, since the electromagnetic solenoid 136 cannot push the spool 138 against the coil spring 134, the oil control valve 17
0 is the state shown in FIG.

For this reason, the position of the intake camshaft 23 where the profile having the largest valve lift in the profile of the intake cam 28 abuts the cam follower 21a is the stable position. Therefore, in the case where the power supply to the electromagnetic solenoid 136 is stopped, the valve lift amount shown in FIG. 7B is the maximum and there is no valve overlap.

Next, due to the failure of the oil pump P or the rupture of an oil passage or the like from the oil pump P to the variable lift actuator 25 via the oil control valve 170, no hydraulic pressure is supplied to the variable lift actuator 25 at all. Let us consider a case where a failure occurs.

In this case, similarly to the case described in the second embodiment, the intake camshaft 23 receives a force for moving in the direction opposite to the arrow A from the cam follower 21a, and the intake camshaft 23 The force which moves in the direction is received from the internal teeth 157 of the cover 154.

As described above, the variable valve operating device according to the third embodiment is designed so that the force for moving the intake camshaft 23 in the direction of arrow A in the drawing becomes larger among the two opposing forces. .

Therefore, the ring gear 162 moves in the direction of arrow A together with the intake camshaft 23. Therefore, the state shown in FIG. 8 is settled as a stable position. That is, in the failure in which the hydraulic pressure does not act on the variable lift amount actuator 25, the valve lift amount is the maximum as shown in FIG. 7B, but there is no valve overlap.

As described above, the stable position of the intake camshaft 23 is the same in both the case where the power supply to the electromagnetic solenoid 136 is stopped and the case where the hydraulic pressure is not applied to the variable lift amount actuator 25.

According to the third embodiment described above, the following effects can be obtained. (I). As described above, in the present variable valve apparatus, the stable position of the intake camshaft 23 is unified to the same position as in FIG. Therefore, the same effect as (a) of the first embodiment is obtained.

(B). Further, as shown in FIG. 7B, in any failure, there is no valve overlap. As a result, stable rotation of the engine 11 becomes possible, and evacuation traveling can be made possible.

[Fourth Embodiment] In the fourth embodiment, it is assumed that the intake camshaft 23 is rotating clockwise as viewed from the side of the lift variable actuator 25, and both the outer teeth 163 and the inner teeth 157 have a right-hand thread. This embodiment is different from the second embodiment in that the spline shape is used. Another configuration is the second embodiment.
Therefore, the description will be made with reference to FIGS.

Thus, when the electromagnetic solenoid 136 is in the demagnetized state, the ring gear 162 moves together with the intake camshaft 23 in the direction opposite to the arrow A as shown in FIG. As a result, the low lift side of the intake cam 28 comes into contact with the cam follower 21a of the intake valve 21, so that the lift amount of the intake valve 21 is reduced and the valve opening period is shortened. Further, the rotation phase of the intake camshaft 23 is the most retarded as viewed from the lift amount variable actuator 25 by the action of the beveled outer teeth 163 and the inner teeth 157. Therefore, at this time, as shown in FIG. 10A, the lift state of the intake valve 21 with respect to the exhaust valve 20 is such that the valve lift amount is the minimum, the valve lift amount is retarded to the maximum, and there is no valve overlap. It has become.

On the other hand, when the electromagnetic solenoid 136 is excited, the ring gear 162 moves together with the intake camshaft 23 in the direction of arrow A as shown in FIG. As a result, the high lift side of the intake cam 28 comes into contact with the cam follower 21a of the intake valve 21, so that the lift amount of the intake valve 21 increases and the valve opening period becomes longer. Further, the rotation phase of the intake camshaft 23 as viewed from the lift variable actuator 25 becomes the most advanced side due to the action of the beveled outer teeth 163 and the inner teeth 157. Therefore, at this time, as shown in FIG. 10B, the lift amount of the intake valve 21 is maximum with respect to the exhaust valve 20 side, and the valve overlap is maximized by the maximum advance angle. Has become.

Here, in the above configuration, the ECU 1
It is assumed that a failure occurs in which a current cannot be supplied to the electromagnetic solenoid 136 due to a disconnection of a conductor from the oil control valve 170 to the electromagnetic solenoid 136 of the oil control valve 170.

In this case, since the electromagnetic solenoid 136 cannot push the spool 138 against the coil spring 134, the oil control valve 17
0 is the state shown in FIG.

Therefore, in the intake camshaft 23, the position where the profile having the smallest valve lift in the profile of the intake cam 28 abuts the cam follower 21a is the stable position. Therefore, in the case of a failure in which power supply to the electromagnetic solenoid 136 is stopped, as shown in FIG. 10A, the valve lift is the minimum, and there is no valve overlap.

Next, due to the failure of the oil pump P or the rupture of the oil path from the oil pump P to the variable lift actuator 25 via the oil control valve 170, no hydraulic pressure is supplied to the variable lift actuator 25 at all. Let us consider a case where a failure occurs.

In this case, no oil pressure is applied to the ring gear 162 from the high lift side hydraulic chamber 165 or the low lift side hydraulic chamber 166, and the ring gear 162 cannot restrain the axial position of the intake camshaft 23.

However, since the cam surface of the intake cam 28 is tapered, the contact pressure with the cam follower 21a causes the intake camshaft 23 to receive a force moving in the direction opposite to the arrow A shown in the figure from the cam follower 21a.

Further, the internal teeth 157 of the cover 154 and the external teeth 163 of the ring gear 162 are right-handed bevels. For this reason, the intake camshaft 23 moves in the direction opposite to the arrow A in the drawing based on the friction that the intake cam 28 receives from the cam follower 21a on the journal bearing or the intake cam 28 provided in the cylinder head 14 (not shown). The force is received from the internal teeth 157 of the cover 154.

That is, these two forces are both forces for moving the intake camshaft 23 in the direction opposite to the arrow A in the drawing. Therefore, the ring gear 162 moves in the direction opposite to the arrow A together with the intake camshaft 23. Therefore, the state shown in FIG. 3 is settled as a stable position.
That is, in the case of a failure in which the hydraulic pressure does not act on the lift variable actuator 25, as shown in FIG.
The valve lift is the minimum, and there is no valve overlap.

As described above, the stable position of the intake camshaft 23 is the same regardless of the failure in which the power supply to the electromagnetic solenoid 136 is stopped and the failure in which the hydraulic pressure does not act on the variable lift amount actuator 25.

According to the fourth embodiment described above, the following effects can be obtained. (I). As described above, in the present variable valve apparatus, the stable position of the intake camshaft 23 is unified to the position shown in FIG. Therefore, the same effect as (a) of the first embodiment is obtained.

(B). Further, as shown in FIG. 10 (A), there is no valve overlap in any failure. Thus, stable rotation of the engine 11 becomes possible, and limp-home traveling can be made possible.

[Fifth Embodiment] In the fifth embodiment, as shown in FIGS. 11 and 12, the intake camshaft 23 together with the ring gear 162 is placed in the high lift side hydraulic chamber 165 by arrows. The difference is that a spring 200 biasing in the A direction is provided. The urging force of the spring 200 is set to be larger than the sum of the two forces for moving the intake camshaft 23 in the direction opposite to the arrow A described in the fourth embodiment.

Further, an oil passage which is supplied from the oil control valve 170 to the high lift side hydraulic chamber 165 and the low lift side hydraulic chamber 166 of the lift variable actuator 25 is mounted in reverse to the case of the fourth embodiment. (This is the same as in the third embodiment). That is,
An oil passage P21 from the supply / discharge port 118 is connected to the low lift side hydraulic chamber 166, and an oil passage P22 from the supply / discharge port 120.
Is connected to the high lift side hydraulic chamber 165.

Incidentally, the external teeth 163 of the ring gear 162,
The internal teeth 157 of the cover 154 are both oblique teeth, and have a right-hand spline shape as in the fourth embodiment.

As a result, in the demagnetized state of the electromagnetic solenoid 136, as shown in FIG. 11, oil pressure is supplied from the supply / discharge port 120 to the high lift side hydraulic chamber 165, and the ring gear 162 is shown together with the intake camshaft 23. Move in the direction of arrow A. As a result, the high lift side of the intake cam 28 comes into contact with the cam follower 21a of the intake valve 21, so that the lift amount of the intake valve 21 increases,
The valve opening period becomes longer. Furthermore, the outer teeth 163 and the inner teeth 1 of the bevel teeth
57, the lift amount variable actuator 25
When viewed from above, the rotational phase of the intake camshaft 23 is the most advanced. Therefore, at this time, in the lift state of the intake valve 21, the valve lift amount shown in FIG. 10B is the maximum with respect to the exhaust valve 20 side, and the close timing Ci is the most advanced state. .

On the other hand, when the electromagnetic solenoid 136 is excited, the ring gear 162 moves together with the intake camshaft 23 in the direction opposite to the arrow A as shown in FIG. As a result, the low lift side of the intake cam 28 comes into contact with the cam follower 21a of the intake valve 21, so that the lift amount of the intake valve 21 is reduced and the valve opening period is shortened. Further, the rotation phase of the intake camshaft 23 is the most retarded as viewed from the lift amount variable actuator 25 by the action of the beveled outer teeth 163 and the inner teeth 157. Accordingly, at this time, the lift amount of the intake valve 21 with respect to the exhaust valve 20 side is the minimum valve lift amount shown in FIG.

Here, in the above configuration, the ECU 1
It is assumed that a failure occurs in which a current cannot be supplied to the electromagnetic solenoid 136 due to a disconnection of a conductor from the oil control valve 170 to the electromagnetic solenoid 136 of the oil control valve 170.

In this case, since the electromagnetic solenoid 136 cannot push the spool 138 against the coil spring 134, the oil control valve 17
0 is in the state shown in FIG.

Therefore, in the intake camshaft 23, the position where the profile having the largest valve lift in the profile of the intake cam 28 contacts the cam follower 21a is the stable position. Therefore, in the case of a failure in which the power supply to the electromagnetic solenoid 136 is stopped, the valve lift amount is the maximum and the closing timing Ci, as shown in FIG.
Becomes the most advanced state.

Next, due to the failure of the oil pump P or the rupture of the oil path from the oil pump P to the variable lift actuator 25 via the oil control valve 170, no hydraulic pressure is supplied to the variable lift actuator 25 at all. Let us consider a case where a failure occurs.

In this case, as in the case of the fourth embodiment, the intake camshaft 23 receives from the cam follower 21a a force moving in the direction opposite to the arrow A shown in the figure, and further applies the force in the same direction as the internal teeth of the cover 154. We receive from 157.

As described above, the spring 200
Is greater than the total force of these two forces than the intake camshaft 23
Is large in the direction of arrow A in the figure. For this reason, the ring gear 162 moves together with the intake camshaft 23 by the arrow A.
Move in the direction. Therefore, the state shown in FIG. 11 is settled as a stable position. That is, in the case where the hydraulic pressure does not act on the lift variable actuator 25,
The valve lift amount shown in (B) is the maximum and the closing timing is advanced to the maximum.

As described above, the stable position of the intake camshaft 23 is the same regardless of the failure in which the power supply to the electromagnetic solenoid 136 is stopped and the failure in which the hydraulic pressure does not act on the lift variable actuator 25.

According to the fifth embodiment described above, the following effects can be obtained. (I). As described above, in this variable valve apparatus, the stable position of the intake camshaft 23 is unified to the same position as that in FIG. Therefore, the same effect as (a) of the first embodiment is obtained.

(B). In addition, as shown in FIG. 10B, in any failure, the intake valve 21 can be closed at the earliest, and the startability of the engine 11 is improved. Therefore, it is possible to start the vehicle early after the failure and perform the limp-home running.

[Other Embodiments] In the first to fourth embodiments, a spring is used to quickly move to the above-described stable position when the hydraulic pressure stops working as in the fifth embodiment. You may do so.

In each of the above embodiments, the three-dimensional cam and the variable lift amount actuator 25 are applied to the intake camshaft 23. However, the three-dimensional cam and the variable lift amount are changed to the exhaust camshaft 22 side. Actuator 25
May be applied. Further, a three-dimensional cam and a variable lift amount actuator 25 may be applied to both the exhaust camshaft 22 and the intake camshaft 23.

FIG. 13 shows a function in the case where the configuration of the variable valve of the first embodiment is applied to the exhaust camshaft 22 side. FIG. 13A shows a state where the exhaust camshaft 22 is in a stable position in any failure. Thus, the opening timing of the exhaust valve 20 is most retarded, in addition to the effect (a) of the first embodiment,
Since the valve overlap is eliminated, the rotation of the engine 11 is stabilized, and the limp-home running becomes possible.

FIG. 14 shows a function in the case where the configuration of the variable valve according to the second and third embodiments is applied to the exhaust camshaft 22 side. Among them, Embodiment 2 is described as an exhaust camshaft 2
14A, the state shown in FIG. 14A is a stable position of the exhaust camshaft 22 in any failure. By doing so, together with the effect (a) of the first embodiment,
Since the valve overlap is eliminated, the rotation of the engine 11 is stabilized, and the limp-home running becomes possible.

Further, the third embodiment is applied to the exhaust camshaft 22 side, and the state shown in FIG. 14B is a stable position of the exhaust camshaft 22 in any failure. By doing so, the opening timing of the exhaust valve 20 is made the most retarded, in addition to the effect (a) of the first embodiment, so that the rotation of the engine 11 is stabilized and limp-home traveling is possible.

FIG. 15 shows the function when the variable valve arrangement of the fourth or fifth embodiment is applied to the exhaust camshaft 22 side. Among them, the fourth embodiment is described as an exhaust camshaft 2.
Applying to the second side, the state of FIG. 15A is a stable position of the exhaust camshaft 22 in any failure. By doing so, together with the effect (a) of the first embodiment,
Since the opening timing of the exhaust valve 20 is most retarded,
The rotation of the engine 11 is stabilized, and limp-home running becomes possible.

Further, by applying the fifth embodiment to the exhaust camshaft 22 side, the state shown in FIG. 15B is set to a stable position of the exhaust camshaft 22 in any failure. By doing so, the valve overlap is eliminated along with the effect (a) of the first embodiment.
The rotation of the vehicle is stabilized, and limp-home running becomes possible.

In the second embodiment, the stable position of the intake camshaft 23 at the time of failure is completely opposite to that of the third embodiment. Which one to use depends on the engine 1
It may be determined at the time of design depending on which is more advantageous depending on the type. The relationship between the fourth and fifth embodiments is the same. Further, the relationship in the exhaust camshaft 22 described above is the same.

Although the embodiments of the present invention have been described above, the embodiments of the present invention include the following various technical items in addition to the technical items described in the claims. It should be noted that it has.

(1). The lift amount variable actuator is such that, when the camshaft is moved in the axial direction, a phase of a cam nose position of the three-dimensional cam moves in an advance direction or a retard direction, and the stable position is 2. The variable valve operating device according to claim 1, wherein the cam nose position is a position where the most retarded angle is reached and the valve lift amount is maximized.

(2). The lift amount variable actuator is such that, when the camshaft is moved in the axial direction, a phase of a cam nose position of the three-dimensional cam moves in an advance direction or a retard direction, and the stable position is 2. The variable valve operating device according to claim 1, wherein the cam nose position is a position where the most advanced angle is obtained and the valve lift amount is the maximum.

(3). By providing an urging means for urging the camshaft in the direction of the stable position, the camshaft is moved to the stable position when the hydraulic pressure from the hydraulic pressure generating source is not supplied to the lift variable actuator. 2. The apparatus according to claim 1, wherein
5. The variable valve operating device according to any one of items 4 to 4.

[0127]

According to the first aspect of the present invention, the stable position in the case of the failure in which the supply of the hydraulic pressure is stopped is the same as the stable position in the case of the failure in which the supply control of the hydraulic fluid control valve is stopped. It is configured so that
As a result, the camshaft position and the valve lift amount are the same regardless of which failure occurs, and the failure can always be dealt with by one fail-safe process. Therefore, it is possible to prevent an increase in the program development process and the memory capacity.

The variable valve operating device according to the second aspect is the first aspect.
In the configuration described above, the stable position is a position where the valve lift amount is minimized. As described above, by setting both the stable position in the case of the failure in which the supply of the hydraulic pressure is stopped and the stable position in the case of the failure in which the supply control of the hydraulic fluid control valve is stopped, the position where the valve lift is minimized. The operation and effect according to claim 1 are produced. Further, since this stable position is a position where the valve lift is minimized, in the case of an intake valve, rotation stability and engine startability can be secured by reducing valve overlap and advancing the closing timing. , Evacuation traveling can be enabled. In the case of an exhaust valve, rotation stability can be ensured by reducing valve overlap and delaying the opening timing, so that limp-home traveling can be performed.

The variable valve device according to the third aspect is the first aspect.
Or the lift amount variable actuator moves the cam nose position of the three-dimensional cam in an advance direction or a retard direction when moving the cam shaft in the axial direction. The stable position is a position where the cam nose position is the most retarded.

With this configuration, the first aspect of the present invention is described.
Alternatively, in addition to the operation and effect of the second aspect, especially in the case of an intake valve, the valve overlap is reduced, so that the rotational stability is improved. Particularly in the case of an exhaust valve, the opening timing is retarded, so that rotational stability is enhanced.

The variable valve operating device according to the fourth aspect is the first aspect.
Or the lift amount variable actuator moves the cam nose position of the three-dimensional cam in an advance direction or a retard direction when moving the cam shaft in the axial direction. The stable position is a position where the cam nose position is at the most advanced angle.

With this configuration, the first aspect of the present invention is provided.
In addition, in addition to the operation and effect of the second aspect, especially in the case of an intake valve, since the closing timing is advanced, the engine startability is enhanced. In the case of an exhaust valve, the rotation stability is improved because the valve overlap is reduced.

[Brief description of the drawings]

FIG. 1 is a schematic configuration explanatory view of a variable valve operating device according to a first embodiment.

FIG. 2 is a perspective view of a three-dimensional cam used in the first embodiment.

FIG. 3 is a configuration explanatory view of a variable lift amount actuator and an oil control valve used in the first embodiment.

FIG. 4 is an operation explanatory diagram of a variable lift amount actuator and an oil control valve used in the first embodiment.

FIG. 5 is an operation explanatory diagram of the oil control valve used in the first embodiment.

FIG. 6 is an explanatory diagram of a valve timing operation of an intake valve according to the first embodiment.

FIG. 7 is an explanatory diagram of a valve timing operation of an intake valve according to a second embodiment.

FIG. 8 is a configuration explanatory view of a variable lift amount actuator and an oil control valve used in a third embodiment.

FIG. 9 is an operation explanatory view of a variable lift amount actuator and an oil control valve used in the third embodiment.

FIG. 10 is an explanatory diagram of a valve timing operation of an intake valve according to a fourth embodiment.

FIG. 11 is a configuration explanatory view of a variable lift amount actuator and an oil control valve used in a fifth embodiment.

FIG. 12 is an operation explanatory view of a variable lift amount actuator and an oil control valve used in the fifth embodiment.

FIG. 13 is a functional explanatory diagram of the embodiment in which the variable valve arrangement of the first embodiment is applied to the exhaust camshaft side.

FIG. 14 is a functional explanatory diagram of an embodiment in which the variable valve mechanism according to the second or third embodiment is applied to the exhaust camshaft side.

FIG. 15 is an explanatory diagram of functions in an embodiment in which the variable valve mechanism according to the fourth or fifth embodiment is applied to the exhaust camshaft side.

[Explanation of symbols]

11 gasoline engine, 12 piston, 13 cylinder block, 13a oil pan, 14 cylinder head, 14b bearing part, 15 crankshaft, 15
a ... Timing pulley, 16 ... Connecting rod, 17 ... Combustion chamber, 18 ... Exhaust passage, 19 ... Intake passage, 20 ... Exhaust valve, 21 ... Intake valve, 21a ... Cam follower, 22 ...
Exhaust camshaft, 23 ... Intake camshaft, 24a ...
Timing pulley, 25 lift variable actuator, 25a timing pulley, 26 timing belt, 27 exhaust cam, 28 intake cam, 116 casing, 118 first supply / discharge port, 120 second supply / discharge port, 122: first discharge port, 124: second discharge port, 126: supply port, 128: supply passage, 130 ...
Discharge passage, 132: valve portion, 134: coil spring,
136 ... electromagnetic solenoid, 138 ... spool, 151 ...
Cylindrical part, 152 ... disk part, 153 ... external teeth, 154 ... cover, 155 ... bolt, 157 ... internal teeth, 158 ... hollow bolt, 159 ... pin, 162 ... ring gear, 162a ... disk-shaped ring part, 163 ... outside Tooth, 165: High lift side hydraulic chamber, 166: Low lift side hydraulic chamber, 167: High lift control oil path, 168: Low lift control oil path, 170: Oil control valve, 172: Oil path, 180: Electronic control unit (ECU), 182 CPU, 183 ROM, 1
84 RAM, 185 backup RAM, 186
Bus, 187: external input circuit, 188: external output circuit,
190: crank side electromagnetic pickup, 194: shaft position sensor, 200: spring, P: oil pump, P1, P11, P12, P2, P21, P22 ... oil passage.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Shuji Nakano 1 Toyota Town, Toyota City, Aichi Prefecture Inside Toyota Motor Corporation (72) Inventor Shinichiro Kikuoka 1 Toyota Town, Toyota City, Aichi Prefecture Inside Toyota Motor Corporation F-term (reference) 3G016 AA08 AA12 AA19 BA03 BA06 BA22 BA28 BA36 BA40 BA41 BB04 CA08 CA24 CA27 CA29 CA36 CA44 CA45 DA01 DA04 DA22 DA23 GA01 GA06 3G092 AA01 AA11 DA01 DA02 DA04 DA10 DA12 DF04 DF09 DG02 EA03 EA09 EA09 EA25 EA28 EA29 EB08 EC01 FA50

Claims (4)

[Claims] 1. A three-dimensional cam provided on a camshaft of an internal combustion engine and having a cam profile continuously changing in a rotation axis direction, by moving the camshaft in the axis direction,
A lift variable actuator that continuously varies a valve lift by the three-dimensional cam; a hydraulic pressure source for generating hydraulic pressure for operating the lift variable actuator; and the lift from the hydraulic pressure source A hydraulic pressure control valve that adjusts the movement position of the camshaft by controlling the supply of the hydraulic pressure to the variable-volume actuator, wherein the supply of the hydraulic pressure by the hydraulic fluid control valve is provided. A stable position where the camshaft is directed by the hydraulic pressure when control is stopped, and a stable position where the camshaft is directed when the hydraulic pressure from the hydraulic pressure generation source is not supplied to the lift variable actuator. And a variable valve operating device. 2. The variable valve operating apparatus according to claim 1, wherein the stable position is a position where the valve lift is minimized. 3. The variable lift amount actuator moves a cam nose position of the three-dimensional cam in an advance direction or a retard direction when the cam shaft is moved in the axial direction. 3. The variable valve apparatus according to claim 1, wherein the stable position is a position where the cam nose position is the most retarded. 4. The variable lift amount actuator moves a cam nose position of the three-dimensional cam in an advance direction or a retard direction when the cam shaft is moved in the axial direction. 3. The variable valve operating device according to claim 1, wherein the stable position is a position where the cam nose position is at the most advanced angle.