JP2003129812A - Variable valve unit of internal-combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an assisting force by a magnetic force and improve responsivity when a stroke of a piston of a hydraulic actuator is large. SOLUTION: An auxilliary shaft 17 of a variable lift actuator 100 has a first helical spline 107a and a second helical spline 107b which has a larger lead than the one of the first helical spline 107a. The first helical spline 107a is engaged by a helical spline 101b which is formed at a housing 101. A secondary subgear 110 is provided so that it cannot be relatively rotated against the housing 101, and is equipped with a helical spline 110a which engages the second helical spline 107b. Permanent magnets 111 and 112 whose polarities are different from each other are provided on the opposing plane of a subgear 110 and an end cover 103 of the housing 101, and a magnetic assisting force is applied to the auxilliary shaft 107 via the subgear 110.

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 system for an internal combustion engine, and more particularly, to continuously changing the valve lift amount by interlocking with the axial position of the control shaft by moving the control shaft in the axial direction. And a variable valve operating device.

[0002]

2. Description of the Related Art In order to continuously adjust the valve lift amount of an intake valve of an internal combustion engine according to the operating state of the internal combustion engine, a cam provided with a three-dimensional cam whose cam nose height gradually increases in the axial direction. A variable valve operating device is known in which a shaft is moved in the axial direction (Japanese Patent Laid-Open No. 2000-54).
814 publication).

[0003]

In the variable valve operating device in which the valve lift amount is continuously variable by moving the cam shaft in the axial direction as described above, the cam surface of the three-dimensional cam is inclined in the axial direction. Therefore, thrust force is generated in the direction to reduce the valve lift amount. Moreover, as the valve lift amount increases, the compression amount of the valve spring increases and the restoring force of the valve spring gradually increases, so that the thrust force also increases.

An actuator for moving the camshaft in the axial direction when the variable valve device is used to adjust the intake air amount of the internal combustion engine by the valve lift amount of the intake valve instead of the throttle valve. High responsiveness is required. Particularly when a hydraulic actuator is used, it is required to reduce the flow rate of hydraulic oil by reducing the piston diameter in order to achieve high response. However, if the piston diameter is reduced, the output of the actuator cannot cope with the increase in the thrust force described above, and the minimum operating hydraulic pressure in the case where the valve lift amount is large may deteriorate, or the responsiveness may deteriorate.

In order to solve these problems, an electromagnet is provided inside the hydraulic actuator so that the piston is attracted to the high lift side (large valve lift amount) by the magnetic force. Two
Issue No. 11712 of December 28, 000).

However, in the hydraulic actuator provided with such an electromagnet, the magnitude of the magnetic force is inversely proportional to the square of the distance. Therefore, when the stroke amount of the piston is set large, the piston moves to the low lift side. When doing so, there is a problem that the magnetic force is significantly reduced and there is almost no assist force.

The present invention has been made in view of the above circumstances, and an object thereof is to obtain an assisting force by a magnetic force even when a stroke amount of a piston of a hydraulic actuator is set to be large. Another object of the present invention is to provide a variable valve operating device for an internal combustion engine that can improve the responsiveness.

[0008]

[Means for Solving the Problems] Means and effects for achieving the above object will be described below. Claim 1
The invention described in (1) is a variable valve actuation device for an internal combustion engine, wherein the valve lift amount is continuously variable by interlocking with the axial position of the control shaft by moving the control shaft in the axial direction. A hydraulic actuator having a piston that is provided in a part of the shaft and that moves in the axial direction integrally with the control shaft by hydraulic pressure supplied into the cylinder of the housing is provided, and the hydraulic actuator is based on the movement of the control shaft. Moving in the same direction as the control shaft and moving smaller than the moving amount, a connecting means for connecting the control shaft and the movable body so that they cannot move relative to each other at the relative position, and the movable body. High lift of the control shaft against the body Characterized in that it comprises a magnet for applying a suction force to.

According to the above construction, the attractive magnetic force of the magnet acting on the movable body is transmitted to the control shaft through the connecting means, and the assist force to the high lift side acts on the control shaft. At this time, the movable body moves in the same direction as the control shaft based on the movement of the control shaft and moves smaller than the amount of movement, so that the change in the distance between the magnet and the movable body becomes small. Therefore, even when the stroke amount of the piston is set to be large, the magnetic force assist force can be secured by suppressing the decrease in the attractive magnetic force when the piston moves to the low lift side. It is possible to improve the property.

According to a second aspect of the present invention, in the first aspect, the control shaft has a first helical spline, a first helical spline extending in the same swivel direction as the first helical spline, and larger than the lead of the first helical spline. Two helical splines, the first helical spline is meshed with a third helical spline formed in the housing, and the movable body is the second helical spline.
A fourth helical spline that meshes with the helical spline is provided, and the fourth helical spline and the second helical spline are provided.
The connecting means is constituted by a helical spline, and rotation restricting means for disabling relative rotation of the movable body and the housing around the axis of the control shaft is provided between the movable body and the housing. It is characterized by

According to the above construction, the piston is moved to the low lift side or the high lift side by the hydraulic pressure supplied to the cylinder. At this time, the control shaft moves in the axial direction while rotating around its axis due to the engagement of the first helical spline of the control shaft and the third helical spline of the housing. The fourth helical spline of the movable body is meshed with the second helical spline larger than the lead of the first helical spline, but the movable body and the housing cannot rotate relative to each other around the axis of the control shaft by the rotation restricting means. is there. Therefore, the movable body moves in the same direction as the control shaft based on the movement of the control shaft while rotating, and also moves smaller than the moving amount. The moving amount of the movable body is the lead difference between the second helical spline and the first helical spline. When the movement of the control shaft and the movable body is stopped, the control shaft and the movable body are connected so as to be relatively immovable by the meshing of the second helical spline and the fourth helical spline. Therefore, the attractive magnetic force of the magnet acting on the movable body can be transmitted to the control shaft, and the assist force to the high lift side can be applied to the control shaft.

According to a third aspect of the present invention, in the second aspect, the rotation restricting means is a first straight spline formed on the outer periphery of the movable body so as to extend in the axial direction, and the first straight spline. A second straight spline may be formed on the housing so as to mesh with the spline.

According to this structure, the movable body and the housing can be made relatively non-rotatable around the axis of the control shaft, and the movable body is moved in the same direction as the control shaft based on the movement of the control shaft. At the same time, the amount of movement can be made smaller than that amount.

According to a fourth aspect of the present invention, in any one of the first to third aspects, a camshaft rotatably driven by a crankshaft of an internal combustion engine, a cam provided on the camshaft, and the camshaft. Are swingably supported by different shafts, and have an input part and an output part, so that when the input part is driven by the cam, an intermediary drive mechanism that drives a valve at the output part, and movement in the axial direction And the relative position between the input shaft and the output shaft of the intermediary drive mechanism by moving the control shaft in the axial direction. By including the hydraulic actuator that adjusts the phase difference, the valve lift amount is continuously variable in association with the axial position of the control shaft. To.

The variable valve operating device may include a cam shaft, a cam, an intermediary drive mechanism, a control shaft, and a hydraulic actuator. Even in such a structure, the structure of the locking means described above can restrict the movement of the control shaft to the high lift side and hold the control shaft on the low lift side, thereby suppressing the unstable operation of the control shaft. be able to.

According to a fifth aspect of the present invention, in any one of the first to third aspects, the three-dimensional cam whose cam profile changes in the axial direction is moved in the axial direction so that the valve lift amount is continuous. It is a variable valve mechanism that is variable, and the amount of movement of the control shaft in the axial direction is interlocked with the amount of movement of the three-dimensional cam in the axial direction.

The variable valve operating device may include the three-dimensional cam and the control shaft. Even in such a structure, the structure of the locking means described above can restrict the movement of the control shaft to the high lift side and hold the control shaft on the low lift side, thereby suppressing the unstable operation of the control shaft. be able to.

According to a sixth aspect of the present invention, in the fifth aspect, the control shaft doubles as a cam shaft of the three-dimensional cam. As described above, the control shaft may also serve as the cam shaft of the three-dimensional cam, and by the configuration of the locking means described above, movement of the control shaft to the high lift side can be restricted to hold the control shaft on the low lift side. Therefore, the unstable operation of the control shaft can be suppressed.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) FIG. 1 is a gasoline engine (hereinafter abbreviated as "engine") as an internal combustion engine equipped with a variable valve operating device to which the above-described invention is applied.
FIG. 3 is a block diagram showing a schematic configuration of a control system and its control system.

The engine 2 is mounted on an automobile for driving the automobile. This engine 2
A cylinder block 4, a piston (not shown), a cylinder head 8 mounted on the cylinder block 4, and the like are provided. A plurality of cylinders, for example, four cylinders 2a in this case, are formed in the cylinder block 4, and a combustion chamber 10 defined by the cylinder block 4, the piston and the cylinder head 8 is formed in each cylinder 2a.

Each combustion chamber 10 has a first intake valve 12a, a second intake valve 12b, and a first exhaust valve 16 respectively.
a and the second exhaust valve 16b are arranged. The first intake valve 12a has a first intake port 14a, the second intake valve 12b has a second intake port 14b, the first exhaust valve 16a has a first exhaust port 18a, and the second exhaust valve 16a.
b opens and closes the second exhaust port 18b.

The first intake port 14a and the second intake port 14b of each cylinder 2a are connected to a surge tank 32 via an intake passage 30a formed in the intake manifold 30. Fuel injectors 34 are arranged in the respective intake passages 30a so that fuel can be injected into the first intake port 14a and the second intake port 14b.

The surge tank 32 is connected to an air cleaner 42 via an intake duct 40. No throttle valve is arranged in the intake duct 40.
The intake air amount control according to the operation of the accelerator pedal 74 and the engine speed NE during idle speed control is performed by adjusting the valve lift amounts of the first intake valve 12a and the second intake valve 12b.

Both intake valves 12a and 12b are driven by a lift of an intake cam 45a provided on an intake cam shaft 45 via an intermediary drive mechanism 120, which will be described later, arranged on the cylinder head 8 as shown in FIG. This is done by transmitting motion. In this transmission, the valve lift amount is adjusted by adjusting the lift transmission state by the intermediary drive mechanism 120 by the action of the lift amount variable actuator 100 described later. The intake camshaft 45 is interlocked with the rotation of a crankshaft 49 of the engine 2 via a timing sprocket (a timing gear or a timing pulley) provided at one end and a timing chain 47.

The first exhaust valve 16a which opens and closes the first exhaust port 18a and the second exhaust valve 1 which opens and closes the second exhaust port 18b of each cylinder 2a shown in FIG.
6b is an exhaust camshaft 46 accompanying the rotation of the engine 2.
The exhaust cam 46a (FIG. 2) provided in (FIG. 2) is opened and closed with a constant valve lift amount. The first exhaust port 18a and the second exhaust port 18b of each cylinder 2a are connected to the exhaust manifold 48. As a result, the exhaust gas is discharged to the outside via the catalytic converter 50.

An electronic control unit (hereinafter referred to as an ECU) 60 is composed of a digital computer, and has a CPU, a RAM, and a RO that are mutually connected via a bidirectional bus.
M, various driver circuits, an input port, an output port, and the like.

The amount of depression of the accelerator pedal 74 output by the accelerator opening sensor 76 to the input port of the ECU 60 (hereinafter referred to as "accelerator opening ACCP").
An output voltage proportional to, a pulse output every time the crankshaft rotates 30 ° by the crank angle sensor 82,
Intake duct 40 output by intake air amount sensor 84
The output voltage corresponding to the intake air amount GA flowing through the engine 2, the output voltage corresponding to the cooling water temperature THW of the engine 2 output by the water temperature sensor 86 provided in the cylinder block 4 of the engine 2, and the exhaust voltage provided in the exhaust manifold 48. According to the output voltage corresponding to the air-fuel ratio output by the fuel ratio sensor 88, the axial displacement output by the shaft position sensor 90 that detects the axial displacement of the control shaft 132, which will be described later, moved by the lift amount variable actuator 100. The output voltage and the output pulse from the cam angle sensor 92 that detects the cam angle of the intake cam 45a that drives the intake valves 12a and 12b via the intermediary drive mechanism 120 are input. The ECU 60 calculates the current crank angle based on the output pulse of the crank angle sensor 82 and the pulse of the cam angle sensor 92, and calculates the engine speed NE from the frequency of the output pulse of the crank angle sensor 82.

Besides, various signals are input to the input port of the ECU 60, but they are not shown in the present embodiment because they are not important for explanation in this embodiment. The output port of the ECU 60 is connected to each fuel injector 34 via a corresponding drive circuit. The ECU 60 controls each fuel injector 34 according to the operating state of the engine 2.
Valve opening control, and fuel injection timing control and fuel injection amount control are executed.

The output port of the ECU 60 is connected to an oil control valve (hereinafter referred to as "OCV") 94 via a drive circuit, and the ECU 60 controls the OCV 94 according to the operating state of the engine 2 such as the required intake air amount. The variable lift actuator 100 is controlled by the hydraulic control by

Here, the lift amount variable actuator 10
The internal structure of 0 is shown in FIGS. The lift amount variable actuator 100 includes a cylindrical housing 101 and a pair of end covers 102 and 103 provided so as to close the opening portions at both ends of the housing 101. The housing 101 is fixed to the cylinder head 8 by an end cover 102. A partition wall 101a is formed in the middle of the housing 101.
Cylinder 104 in housing 101 by 01a
A sub chamber 105 is formed.

A piston 106 is slidably provided in the cylinder 104, and the piston 106 is integrally provided with an auxiliary shaft 107 as a control shaft penetrating the end cover 102 and the cylinder head 8. The auxiliary shaft 107 is connected to the control shaft 132 via a rolling bearing (not shown). Therefore, the control shaft 132 is interlocked with the movement of the piston 106.

The cylinder 104 is partitioned by a piston 106 into a first hydraulic chamber 108 and a second hydraulic chamber 109. Then, through the OCV 94 described above, the ECU 6
When 0 adjusts the supply and discharge of the hydraulic pressure to the first hydraulic chamber 108 and the second hydraulic chamber 109, the entire piston 106 moves in the axial direction and the axial position of the control shaft 132 is adjusted. Further, the partition wall 101a has an oil drain hole 101c for communicating the second hydraulic chamber 109 with the sub chamber 105.
Are formed. The second through the oil drain hole 101c
The hydraulic pressure in the hydraulic chamber 109 and the hydraulic pressure in the sub chamber 105 are made equal.

The auxiliary shaft 107 has a partition wall 101a.
There is provided a first helical spline 107a and a second helical spline 107b which extend through to the sub chamber 105 side. First helical spline 107a and second
The helical spline 107b extends in the same turning direction (for example, a right-handed spiral). The lead of the second helical spline 107b (the amount of movement in the axial direction per unit turn) is set to be larger than the lead of the first helical spline 107a.

The first helical spline 107a is the third helical spline 101b formed on the partition wall 101a.
Have been meshed with. Therefore, when the piston 106 moves to the low lift side or the high lift side by the hydraulic pressure supplied to the cylinder 104, the first helical spline 10
The auxiliary shaft 107 moves in the axial direction while rotating around its axis due to the meshing of 7a and the third helical spline 101b.

A sub gear 110 as a movable body is housed in the sub chamber 105. A fourth helical spline 110a that meshes with the second helical spline 107b is formed at the center of the sub gear 110. A first straight spline 110b is formed on the outer periphery of the sub gear 110 so as to extend in the axial direction of the auxiliary shaft 107. The first straight spline 110b is formed in the inner circumference of the sub chamber 105 so as to extend in the axial direction of the auxiliary shaft 107.
It is meshed with the straight spline 105a.
Therefore, although the sub gear 110 is allowed to move in the axial direction of the auxiliary shaft 107, the housing 1
01 is not relatively rotatable around the axis of the auxiliary shaft 107. In this embodiment, the first straight spline 110b and the second straight spline 105a.
The rotation restricting means is constituted by and. In addition, the sub gear 110 has an oil drain hole 1 communicating on both left and right sides thereof.
10c is formed. The oil pressures in the sub chambers 105 are made equal via the oil drain holes 110c.

Therefore, when the auxiliary shaft 107 rotates and moves in the axial direction, the sub gear 110 moves to the fourth position.
Based on the meshing between the helical spline 110a and the second helical spline 107b, the auxiliary shaft 10
Move in the same direction as 7. The movement amount of the sub gear 110 at this time is the same as the lead of the second helical spline 107b and the first
It becomes the difference from the lead of the helical spline 107a,
The sub gear 110 moves smaller than the moving amount of the auxiliary shaft 107. Further, when the movement of the auxiliary shaft 107 stops, the movement of the sub gear 110 also stops, and the second helical spline 107b and the fourth helical spline 1
The auxiliary shaft 107 and the sub-gear 110 are connected to each other so as to be relatively immovable by meshing with 10a.

In the sub chamber 105, the sub gear 110
A first permanent magnet 111 having an arbitrary polarity (for example, N pole) is disposed at a portion facing the end cover 103.
A second permanent magnet 112 having a polarity (for example, S pole) different from that of the first permanent magnet 111 is disposed at a position facing the first permanent magnet 111 on the end cover 103. With the first permanent magnet 111 and the second permanent magnet 112, a magnetic attraction force can be applied to the sub gear 110 on the high lift side of the auxiliary shaft 107. Sub gear 11
The magnetic attraction force acting on the second helical spline 10
7b and the fourth helical spline 110a are engaged with each other, and the auxiliary shaft 107 and the control shaft 1
Since it is transmitted to 32, the magnetic force assisting force toward the high lift side can be applied to the control shaft 132.

A stroke sensor core 113 is provided on the auxiliary shaft 107 on the tip side of the second helical spline 107b, and the tip of the stroke sensor core 113 is inserted into a stroke sensor coil 114 attached to the end cover 103. Has been done. As a result, the shaft position of the auxiliary shaft 107, that is, the control shaft 132 is detected, and a signal corresponding to the shaft position is output from the stroke sensor coil 114 to E.
It is output to the CU 60.

The OCV 94 is an electromagnetic solenoid type 4-port 3-position switching valve. As shown in FIG. 3, when the electromagnetic solenoid is demagnetized (hereinafter referred to as "low lift drive state"), the operation in the first hydraulic chamber is performed. The oil is returned to the oil pan 97 via the discharge passage 96. High-pressure hydraulic oil is supplied from the oil pump P into the second hydraulic chamber via the supply passage 95. As a result, the control shaft 132 can be moved in the L direction in FIG. 3 and the valve working angle and the valve lift amount of the intake valves 12a and 12b can be reduced by the function of the intermediary drive mechanism 120.

In the state where the electromagnetic solenoid is 100% excited (hereinafter, referred to as "high lift drive state"),
An oil pump P is introduced into the first hydraulic chamber via a supply passage 95.
Supplies high-pressure hydraulic oil. The hydraulic oil in the second hydraulic chamber is returned to the oil pan 97 via the discharge passage 96. This causes the control shaft 132
And the valve lift amount of the intake valves 12a and 12b can be increased by the function of the intermediary drive mechanism 120.

Furthermore, when the power supply to the electromagnetic solenoid is controlled to a medium state (hereinafter referred to as "neutral state"), the first and second hydraulic chambers are not connected to the supply passage 95 or the discharge passage 96. It will be closed. As a result, the axial movement of the control shaft 132 is stopped and the valve lift of the intake valves 12a and 12b can be maintained.

FIG. 5 shows the relationship between the thrust force that accompanies the amount of movement of the control shaft 132 in the H direction and the magnetic force assist force by the first permanent magnet 111 and the second permanent magnet 112, which is actually designed based on the above-mentioned relationship. That is, the thrust force F generated by the operation of the intermediary drive mechanism 120.
s (however, the action direction of the force is opposite to the assist force) is H
The movement amount of the control shaft 132 in the direction is "0.
(Mm) ”(the limit position in the L direction) has the minimum value Fs1. The thrust force Fs increases as the control shaft 132 moves in the H direction, and the thrust force Fs reaches the maximum value Fs2 at the limit position in the H direction. The intermediary drive mechanism 1
The rising pattern of the thrust force Fs generated by 20 slightly changes depending on the rotation speed of the engine 2. On the other hand, the sub gear 110 based on the movement of the auxiliary shaft 107
Is the read difference between the second helical spline 107b and the first helical spline 107a, which is small. Therefore, the magnetic force assisting force of the first permanent magnet 111 and the second permanent magnet 112 changes as shown by the solid line. The movement amount of the sub gear 110 is set to the auxiliary shaft 10.
When the moving amount is equal to 7, the magnetic force assisting force changes as shown by the chain line. Therefore, even when the stroke amount of the piston 106, that is, the control shaft 132 is set to be large, it is possible to suppress the decrease in the magnetic force assisting force when the control shaft 132 moves to the low lift side, and the magnetic force assisting force can be suppressed. You can secure power.

Next, the intermediary drive mechanism 120 will be described with reference to FIGS. The intermediary drive mechanism 120 includes an input section 122 provided in the center of the figure, a first swing cam 124 (corresponding to an “output section”) provided on the left side of the figure, and a second swing cam 126 provided on the right side of the figure. (Corresponding to “output unit”). Housing 122a of these input parts 122
And each housing 124a of the swing cams 124, 126,
Each of the 126a has a cylindrical shape with the same outer diameter.

FIG. 7 shows each housing 122a, 124a,
It is the perspective view which horizontally fractured | ruptured 126a. Here, the housing 122a of the input part 122 has a space inside in the axial direction, and the helical spline 122b (corresponding to the "input part spline") is formed in a spiral shape of a right-hand screw in the axial direction on the inner peripheral surface of this space. Are formed. Two arms 122c and 122d are formed so as to project in parallel from the outer peripheral surface. A shaft 122e is stretched between the tips of the arms 122c and 122d. The shaft 122e is parallel to the axial direction of the housing 122a, and the roller 122f is rotatably attached.

Housing 124a of the first swing cam 124
Is internally provided with a space in the axial direction, and a helical spline 124b (corresponding to an "output portion spline") formed in a spiral shape of a left screw in the axial direction is formed on the inner peripheral surface of the internal space. The left end of this internal space is covered with a ring-shaped bearing portion 124c having a central hole with a small diameter. A substantially triangular nose 124d is formed so as to project from the outer peripheral surface. One side of the nose 124d is a cam surface 124e that is curved in a concave shape.

Housing 126a of the second swing cam 126
Is internally provided with a space in the axial direction, and a helical spline 126b (corresponding to an "output portion spline") formed in a spiral shape of a left screw in the axial direction is formed on the inner peripheral surface of the internal space. The right end of this internal space is covered with a ring-shaped bearing portion 126c having a center hole with a small diameter. Further, a substantially triangular nose 126d is formed so as to project from the outer peripheral surface. One side of the nose 126d is a cam surface 126e that is curved in a concave shape.

The first swing cam 124 and the second swing cam 12
6 is the input unit 1 with the bearings 124c and 126c outside.
The two end faces of 22 are coaxially contacted with each other, and the whole has a substantially columnar shape having an internal space as shown in FIG.

Input section 122 and two swing cams 124, 1
A slider gear 128 is provided in the internal space constituted by 26.
Are arranged. The slider gear 128 has a substantially columnar shape, and an input helical spline 128a formed in a spiral shape with a right screw is formed in the center of the outer peripheral surface. At the left end of the input helical spline 128a, a first output helical spline 128c formed in a spiral shape of a left screw is formed with a small diameter portion 128b sandwiched therebetween. or,
At the right end of the input helical spline 128a, a second output helical spline 128e formed in a spiral shape of a left screw is formed with the small diameter portion 128d interposed therebetween.
Incidentally, these output helical splines 128c, 128
The outer diameter of e is smaller than the outer diameter of the input helical spline 128a.

A through hole 128f is formed in the slider gear 128 in the central axis direction. A long hole 128g for opening the through hole 128f to the outer peripheral surface is formed in the one small diameter portion 128d. This long hole 128g
Are formed to be long in the circumferential direction.

Through hole 128f of this slider gear 128
A support pipe 130 shown in FIG. 8 is arranged therein so as to be slidable in the circumferential direction. 8A is a plan view and FIG.
8B is a front view and FIG. 8C is a right side view. As shown in FIG. 2, one support pipe 130 is provided commonly to all the intermediary drive mechanisms 120 (here, four). It should be noted that each of the intermediary drive mechanisms 12 is attached to the support pipe 130.
An elongated hole 130a that is elongated in the axial direction is opened for each 0.

Further, a control shaft 132 penetrates through the support pipe 130 so as to be slidable in the axial direction. This control shaft 132 is also common to all the intermediary drive mechanisms 120 like the support pipe 130.
Books are provided. The control shaft 132
A locking pin 132a is projected for each intermediary drive mechanism 120. The locking pin 132a penetrates the elongated hole 130a formed in the support pipe 130. Further, the locking pin 132a of the control shaft 132 is provided with a circumferential elongated hole 128 formed in the slider gear 128.
The tip is also inserted in g.

Due to the axially elongated hole 130a formed in the support pipe 130, the locking pin 132a of the control shaft 132 has the support pipe 130 attached to the cylinder head 8.
Even when fixed, the slider gear 128 can be moved in the axial direction by moving in the axial direction.
Further, the slider gear 128 itself has a long hole 128 in the circumferential direction.
By being locked to the locking pin 132a at g, the axial position is determined by the locking pin 132a, but it is swingable about the axis.

In the slider gear 128, the input helical spline 128a is meshed with the helical spline 122b inside the input section 122. or,
The first output helical spline 128c is meshed with the helical spline 124b inside the first swing cam 124, and the second output helical spline 128e is meshed with the helical spline 126b inside the second swing cam 126.

Each intermediary drive mechanism 12 configured in this way
0 is the bearing portions 124c, 12 of the swing cams 124, 126.
As shown in FIG. 2, on the side of 6c, it is sandwiched by the standing wall portions 136 and 138 formed in the cylinder head 8 and is swingable around the axis, but is prevented from moving in the axial direction. . The standing wall portions 136 and 138 have bearing portions 124c,
A hole is formed at a position corresponding to the center hole of 126c, and the support pipe 130 is fixed therethrough. Therefore, the support pipe 130 is fixed to the cylinder head 8 and does not move or rotate in the axial direction.

Further, the control shaft 132 in the support pipe 130 penetrates the support pipe 130 slidably in the axial direction, and is connected to the auxiliary shaft 107 of the lift variable actuator 100 at one end side as shown in FIG. Has been done. Therefore, the first hydraulic chamber 108 and the second hydraulic chamber 109
By adjusting the hydraulic pressure to the control shaft 132
The axial displacement of the can be adjusted. As a result, the roller 122f of the input section 122 and the swing cam 12 are passed through the control shaft 132 and the slider gear 128.
It is possible to adjust the relative phase difference between the nose 124d of the No. 4,126 and the nose 124d of the No. 4,126. That is, by driving the variable lift amount actuator 100, the valve lift amounts of the intake valves 12a and 12b can be continuously varied as shown in FIGS.

Here, FIG. 9 shows a state of the intermediary drive mechanism 120 in a state where the control shaft 132 is moved to the limit in the H direction by the lift amount variable actuator 100. 9 to 11 show the second swing cam 126.
Shows the mechanism that drives the first intake valve 12a, but the mechanism that the first swing cam 124 drives the second intake valve 12b is also the same, so the first swing cam 124 and the second intake valve 12b are the same. Will also be described.

In the state shown in FIG. 9A, the base circle portion (the portion excluding the nose 45c) of the intake cam 45a is in contact with the roller 122f of the input section 122 of the intermediary drive mechanism 120. Although not shown, the roller 122f is biased by a spring so as to always contact the intake cam 45a side. At this time, the noses 124d and 126d of the rocking cams 124 and 126 are not in contact with the rollers 13a of the rocker arm 13, and the noses 124d and 126d are not in contact with the rollers 13a.
The base circle portion adjacent to d is in contact. For this reason,
The intake valves 12a and 12b are closed.

The intake camshaft 45 rotates, and the nose 45c of the intake cam 45a rotates the roller 122f of the input section 122.
When is pushed down, the input unit 12 in the intermediary drive mechanism 120 is pressed.
Rocking cams 124, 1 from 2 via a slider gear 128
The swing is transmitted to 26. The swing cams 124 and 126 swing so as to push down the noses 124d and 126d.
Therefore, the curved cam surfaces 124e and 126e provided on the noses 124d and 126d immediately contact the rollers 13a of the rocker arm 13 to cover the entire range of the cam surfaces 124e and 126e as shown in FIG. 9B. The roller 13a of the rocker arm 13 is pushed down by using. As a result, the rocker arm 13 swings around the base end portion 13c side supported by the adjuster 13b, and the tip end portion 13d of the rocker arm 13 largely pushes down the stem end 12c. In this way, the intake valves 12a and 12b open the intake ports 14a and 14b with the maximum valve lift amount.

FIG. 10 shows a variable lift amount actuator 10.
0 shows the state of the intermediary drive mechanism 120 when the control shaft 132 is slightly returned in the L direction from the state of FIG.

In FIG. 10A, the base circle portion of the intake cam 45a is in contact with the roller 122f of the input section 122 of the intermediary drive mechanism 120. At this time, the swing cam 1
The noses 124d and 126d of 24 and 126 are not in contact with the roller 13a of the rocker arm 13, and the base circle portions slightly apart from the noses 124d and 126d are in contact with the rollers 13a of the rocker arm 13. Therefore, the intake valve 1
2a and 12b are closed. This is the intermediary drive mechanism 1
Since the slider gear 128 slightly moved in the L direction within the position 20, the roller 122f of the input unit 122 and the swing cam 124,
This is because the relative phase difference between 126 and the noses 124d and 126d has decreased.

The intake camshaft 45 is rotated and the nose 45c of the intake cam 45a is rotated by the roller 122f of the input section 122.
When is pushed down, the input unit 12 in the intermediary drive mechanism 120 is pressed.
Rocking cams 124, 1 from 2 via a slider gear 128
The swing is transmitted to 26. The swing cams 124 and 126 swing so as to push down the noses 124d and 126d.

As described above, in the state of FIG. 10A, the roller 13a of the rocker arm 13 has the nose 124d,
The base circle portion of the intake cam 45a which is separated from 126d is in contact. Therefore, even if the rocking cams 124 and 126 rock, the roller 13a of the rocker arm 13 remains for a while.
Is the curved cam surface 124 of the nose 124d, 126d
e, 126e is kept in contact with the base circle without touching. Then, the curved cam surface 124e,
126e contacts the roller 13a and pushes down the roller 13a of the rocker arm 13 as shown in FIG. 10 (B). As a result, the rocker arm 13 has the base end portion 13
Swing about c. However, since the roller 13a of the rocker arm 13 is initially separated from the noses 124d and 126d, the use range of the cam surfaces 124e and 126e is reduced. Therefore, the rocking angle of the rocker arm 13 becomes small, and the pushing down amount of the stem end 12c by the tip portion 13d of the rocker arm 13, that is, the lift amount becomes small. In this way, the intake valves 12a, 12b are moved to the intake ports 14a, 1 with a valve lift amount smaller than the maximum amount.
4b is opened.

FIG. 11 shows a variable lift amount actuator 10.
The state of the intermediary drive mechanism 120 in the state where the control shaft 132 is returned to the maximum L direction by 0 is shown.
In the state of FIG. 11A, the roller 1 of the rocker arm 13 is
The base circle portion of the intake cam 45a, which is largely separated from the noses 124d and 126d, is in contact with 3a. For this reason, the roller 13a of the rocker arm 13 is in full swing.
Is the curved cam surface 124 of the nose 124d, 126d
e, 126e is kept in contact with the base circle without touching. That is, as shown in FIG. 11B, even if the nose 45c of the intake cam 45a pushes down the roller 122f of the input portion 122 to the maximum extent, the curved cam surfaces 124e and 126e cause the roller 13 of the rocker arm 13 to move.
It is never used to push down a. As a result, the rocker arm 13 does not swing around the base end portion 13c, and the tip end portion 1 of the rocker arm 13 is prevented.
The amount by which the stem end 12c is pushed down by 3d, that is, the valve lift amount becomes "0". Thus, even if the intake camshaft 45 rotates, the intake valves 12a and 12b maintain the closed state of the intake ports 14a and 14b.

In this way, the lift amount variable actuator 1
By adjusting the axial position of the control shaft 132 with 00, the valve lift amount of the intake valves 12a and 12b can be continuously adjusted as shown by the solid curve in the graph of FIG.

When the intake valves 12a and 12b are opened, the valve spring 12d of the intake valves 12a and 12b moves in the direction of narrowing the angle between the arm 122c and the noses 124d and 126d via the rocker arm 13. Since a force acts, a thrust force that moves in the L direction is generated in the slider gear 128. Therefore, the thrust force Fs that tries to move the control shaft 132 in the L direction acts via the locking pin 132a. The larger the valve lift amount of the intake valves 12a and 12b, the larger the valve spring 12d.
The thrust force Fs generated on the control shaft 132 becomes stronger as the amount of movement in the H direction increases. That is, it becomes as shown in FIG.

According to this embodiment described above, the following effects can be obtained. In the lift amount variable actuator 100 of the present embodiment, the sub gear 110 that moves in the same direction as the auxiliary shaft 107 based on the movement of the auxiliary shaft 107 and that moves smaller than the moving amount is provided. And
A magnetic attraction force is applied to the sub gear 110 by the first permanent magnet 111 and the second permanent magnet 112, and this magnetic attraction force is generated through the meshing between the fourth helical spline 110a and the second helical spline 107b. It is transmitted to the control shaft 132. At this time, the sub gear 110 is the auxiliary shaft 1
Since the movement is performed in the same direction based on the movement of 07 and the movement is smaller than the movement amount, it is possible to suppress the decrease in the magnetic force assist force due to the movement of the sub gear 110. Therefore, even when the stroke amount of the piston 106, that is, the control shaft 132 is set to be large, the magnetic force assist force is secured by suppressing the decrease in the magnetic force assist force when the piston 106 moves to the low lift side. Therefore, the responsiveness of the control shaft 132 can be improved.

Further, the auxiliary shaft 107 and the sub gear 110 can be connected to each other by the engagement of the second helical spline 107b and the fourth helical spline 110a so as to be substantially immovable. Therefore, the sub gear 11
The magnetic force assisting force of the permanent magnets 111 and 112 acting on 0 is applied to the auxiliary shaft 107 and the control shaft 132.
The magnetic force assisting force to the high lift side can be applied to the control shaft 132.

The first straight spline 110 b formed on the outer circumference of the sub gear 110 and the housing 10
By engaging with the second straight spline 105a formed in No. 1, it is possible to make the sub gear 110 relatively unrotatable with respect to the housing 101 with a simple configuration.

(Second Embodiment) Next, a second embodiment will be described with reference to FIG. In this embodiment, the intake valve 2
The valve amounts of 12a and 212b are adjusted by the lift amount variable actuator 100.
Is performed by moving the auxiliary shaft 107 as a control shaft, which is connected via the rolling bearing portion 250a, in the axial direction.

The intake camshaft 245 is interlocked with the rotation of the crankshaft of the engine via a timing sprocket (may be a timing gear or a timing pulley) 252 provided at one end. However, since the auxiliary shaft 107 is connected to the intake camshaft 245 through the rolling bearing portion 250a, the intake camshaft 24
The auxiliary shaft 107 does not rotate in association with the rotation of 5. The auxiliary shaft 107 moves integrally with the intake camshaft 245 only in the axial direction.

The timing sprocket 252 connected to the intake camshaft 245 is rotatably supported on the cylinder block of the engine so as not to move in the axial direction. However, since the timing sprocket 252 is connected to the intake camshaft 245 at the center by the straight spline mechanism 252a, the intake camshaft 245 is allowed to move in the axial direction.

The intake cam 245a provided on the intake cam shaft 245 is a three-dimensional cam whose profile continuously changes in the axial direction. Specifically, the intake cams 245a are formed so that the cam nose is low on the right side of the drawing and gradually increases toward the left side. Due to this change in profile, FIG.
The valve lift amount is variable in the same manner as shown in FIG.

Since the intake cam 245a, which is a three-dimensional cam, has the side on which the valve lift amount is increased as shown in the figure on the left side, the restoring force received from the valve springs 212d of the intake valves 212a and 212b is the same as the intake cam 2
Thrust force in the L direction is generated on the intake camshaft 245 by the cam surface of the reference numeral 45a. Then, as shown in FIG. 13, when the piston 106 exists at the limit position in the L direction, the thrust force is small. Piston 10
6 is moved toward the limit position in the H direction, the valve springs 212 of the intake valves 212a and 212b are
The restoring force received from d increases and the thrust force also increases.

According to this embodiment described above, the following effects can be obtained. The variable valve operating device according to the present embodiment is a three-dimensional cam 245a.
And an intake camshaft 245. Even in this case, by using the variable lift amount actuator 100, the auxiliary shaft 107 moves to the low lift side even when the stroke amount of the auxiliary shaft 107, that is, the intake camshaft 245 is set to be large. When the intake camshaft 245 is used, the magnetic force assisting force can be secured by suppressing the decrease in the magnetic force assisting force.
The responsiveness of can be improved.

The embodiment is not limited to the above, but may be modified as follows. In each of the above embodiments, the permanent magnets 11 having different polarities are provided on the facing surfaces of the sub gear 110 and the end cover 103.
1, 112 are provided, the sub gear 110 is made of a magnetic material and the permanent magnet 111 on the side of the sub gear 110 is provided.
May be omitted.

Further, in the configuration in which the sub gear 110 is made of a magnetic material and the permanent magnet 111 on the sub gear 110 side is omitted, an electromagnet may be used instead of the permanent magnet 112 on the end cover 103 side.

In each of the above embodiments, the sub gear 1
An assist spring that biases the sub gear 110 toward the end cover 103 may be provided between the partition wall 10 and the partition wall 101a. According to this configuration, since the assist force in the H direction of the control shaft 132 can be applied as shown by the broken line in FIG. 5, the minimum working hydraulic pressure of the lift amount variable actuator 100 can be reduced, and the responsiveness can be improved. Can be further improved.

In each of the above embodiments, the cylinder 104 of the housing 101 and the sub chamber 105 may be hermetically sealed, and the sub chamber 105 may have an atmospheric pressure atmosphere.
In this case, the oil drain hole 101c of the partition wall 101a and the oil drain hole 110c of the sub gear 110 may be omitted.

Next, other technical ideas that can be understood from the above-described embodiments will be described below. The variable valve operating system for an internal combustion engine according to any one of claims 1 to 6, wherein the movable body is made of a magnetic body, and a magnet having an arbitrary polarity is arranged on the inner surface of the housing.

In any one of claims 1 to 6, the movable body is provided with a first magnet having an arbitrary polarity, and the housing is provided with a second magnet having a polarity different from that of the first magnet. Variable valve operating system for internal combustion engine.

[Brief description of drawings]

FIG. 1 is a block diagram showing a schematic configuration of an engine and its control system according to a first embodiment.

FIG. 2 is an explanatory view of the configuration of a cylinder head portion of the same.

FIG. 3 is a cross-sectional view showing the internal structure of the variable lift amount actuator according to the first embodiment.

FIG. 4 is a sectional view showing an internal structure of the lift amount variable actuator.

FIG. 5 is a graph showing the relationship between thrust force and magnetic force assist force, and stroke of the control shaft.

FIG. 6 is a perspective view showing a configuration of an intermediary drive mechanism of the first embodiment.

FIG. 7 is a partially cutaway perspective view showing the internal structure of the intermediate drive mechanism.

FIG. 8 is a shape explanatory view of a support pipe and a control shaft of the intermediary drive mechanism.

FIG. 9 is an explanatory diagram of a valve lift amount adjusting function by the intermediary drive mechanism of the first embodiment.

FIG. 10 is an explanatory diagram of a valve lift amount adjustment function of the intermediary drive mechanism of the same.

FIG. 11 is an explanatory diagram of a valve lift amount adjusting function of the intermediary drive mechanism in the same manner.

FIG. 12 is a graph showing a change in valve lift amount by the intermediary drive mechanism of the first embodiment.

FIG. 13 is a structural explanatory view of a variable valve mechanism according to the second embodiment.

[Explanation of symbols]

45, 245 ... Cam shaft, 45a ... Cam, 49 ... Crank shaft, 100 ... Lift variable actuator, 101 ... Housing, 101b ... Third helical spline, 104 ... Cylinder, 105a ... Second straight spline, 106 ... Piston, 107 ... auxiliary shaft (control shaft), 107a ... first helical spline, 107b ... second helical spline, 110
a ... Fourth helical spline, 110b ... First straight spline, 111 ... First permanent magnet, 112 ... Second permanent magnet, 120 ... Intermediary drive mechanism, 132 ... Control shaft, 245a ... Three-dimensional cam.

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 3G016 AA08 AA19 BA03 BA06 BA18                       BA28 BA36 BB14 BB17 BB22                       BB25 BB26 CA24 CA25 CA27                       CA29 DA04 DA06 DA08 DA22                       EA22 GA06                 3G018 AB04 AB12 AB17 BA04 BA10                       BA17 CA06 CA09 CA19 DA03                       DA10 DA13 DA15 DA24 DA51                       DA57 DA63 DA74 DA75 DA81                       DA83 FA01 FA06 FA07 GA02

Claims (6)

[Claims] 1. A variable valve operating apparatus for an internal combustion engine, wherein a valve lift amount is continuously variable by interlocking with an axial position of the control shaft by moving the control shaft in the axial direction. A hydraulic actuator having a piston that is integrally provided with the control shaft in the axial direction and that is provided by a hydraulic pressure supplied to a cylinder of the housing, the hydraulic actuator being based on the movement of the control shaft. A movable body that moves in the same direction as the control shaft and that moves smaller than the movement amount; a connecting means that connects the control shaft and the movable body so that they cannot move relative to each other at a relative position; Against the high lift side of the control shaft Variable valve device for an internal combustion engine and a magnet for applying a suction force. 2. The control shaft according to claim 1, wherein the control shaft extends in the same turning direction as the first helical spline and the second helical spline and is larger than the lead of the first helical spline.
A helical spline, the first helical spline is meshed with a third helical spline formed in the housing, the movable body is provided with a fourth helical spline which meshes with the second helical spline, and the fourth helical spline The spline and the second helical spline constitute the connecting means, and the rotation between the movable body and the housing is such that the movable body and the housing cannot rotate relative to each other around the axis of the control shaft. A variable valve operating device for an internal combustion engine provided with a regulating means. 3. The rotation restricting means according to claim 2, wherein the rotation restricting means is formed on an outer periphery of the movable body so as to extend in the axial direction, and the housing is engaged with the first straight spline. A variable valve operating system for an internal combustion engine, which is a second straight spline formed on the. 4. The camshaft according to claim 1, wherein the camshaft is driven to rotate by a crankshaft of an internal combustion engine, a cam provided on the camshaft, and rocks on an axis different from the camshaft. The intermediary drive mechanism, which is movably supported and has an input section and an output section, drives the valve at the output section when the input section is driven by the cam, and the movement amount in the axial direction of the intermediary drive mechanism is The control shaft that is interlocked with the relative phase difference between the input unit and the output unit, and the hydraulic actuator that adjusts the relative phase difference between the input unit and the output unit of the intermediary drive mechanism by moving the control shaft in the axial direction. And a variable valve operating device for an internal combustion engine, wherein the valve lift amount is continuously variable in association with the axial position of the control shaft. 5. A variable movement according to claim 1, wherein a valve lift amount is continuously variable by moving a three-dimensional cam whose cam profile changes in the axial direction in the axial direction. It is a valve mechanism, and the amount of movement of the control shaft in the axial direction is 3
A variable valve operating device for an internal combustion engine, which is interlocked with an axial movement amount of a three-dimensional cam. 6. The variable valve operating system for an internal combustion engine according to claim 5, wherein the control shaft also serves as a cam shaft of the three-dimensional cam.