JP4847981B2 - Variable valve operating device for internal combustion engine - Google Patents

Description

  The present invention relates to a variable valve operating apparatus for an internal combustion engine provided with a variable mechanism that varies a valve timing, which is an operation characteristic of an intake valve or an exhaust valve, which is an engine valve, according to an engine operating state. The present invention relates to an improvement of an actuator that drives a variable mechanism.

  As this type of conventional variable valve operating system for an internal combustion engine, there is one described in the following Patent Document 1 previously filed by the present applicant.

  Briefly, this variable valve operating device is applied to the intake valve side, and the shaft center is eccentric from the shaft center of the drive shaft on the outer periphery of the drive shaft rotating in synchronization with the rotation of the crankshaft. A drive cam is provided, and the rotational force of the drive cam is transmitted through a multi-link transmission mechanism, and the cam surface slides on the upper surface of the valve lifter at the upper end of the intake valve to control the intake valve. It has a swing cam that opens against the spring force of the valve spring.

  The transmission mechanism includes a rocker arm that is disposed above the swing cam and is swingably supported by the control shaft, an annular one end is fitted to the outer peripheral surface of the drive cam, and the other end is one end of the rocker arm. A link arm that is rotatably connected to the rocker, and a link rod that has one end rotatably connected to the other end of the rocker arm and the other end rotatably connected to the cam nose of the swing cam. Has been.

  The control shaft is rotatably supported by a bearing provided at the upper end of the cylinder head, and a control cam whose shaft center is eccentric from the control shaft axis by a predetermined amount is fixed to the outer peripheral surface thereof. Has been.

Then, the control shaft is rotationally controlled by an electric motor that is an actuator and a ball screw transmission means that is a speed reduction mechanism that decelerates the rotation of the electric motor, and the rotational position of the control cam is changed via the control shaft. Thus, by changing the rocking fulcrum of the rocker arm and changing the rolling contact position of the cam surface of the rocking cam with respect to the valve lifter upper surface, the valve lift amount of the intake valve is variably controlled according to the engine operating state. ing.
JP 2002-155716 A

  By the way, as is well known, in general, an internal combustion engine generates a so-called positive and negative alternating torque due to a large spring reaction force of a valve spring when an intake valve or an exhaust valve is opened or closed.

  The alternating torque is transmitted from the swing cam to the control shaft via a transmission mechanism such as a link arm or a rocker arm in the case of the conventional variable mechanism. A large torque fluctuation as shown in the waveform characteristic diagram of FIG.

  Furthermore, the alternating torque transmitted to the control shaft is transmitted to the speed reduction mechanism which is the ball screw transmission means. For this reason, in the ball screw transmission means, there is a risk that severe abnormal noise is generated due to the interference of each part due to the alternating torque in the transmission path such as the meshing part of each ball with the spiral ball groove on the outer periphery of the ball shaft and the ball groove of the ball nut. There is.

The present invention has been devised in view of the technical problem of the conventional variable valve gear, and the invention according to claim 1 is directed to an electric motor that rotates according to an engine operating state, and the electric motor. A speed reduction mechanism that transmits the rotational force to a control shaft that controls the valve timing by varying the phase of the lift center of the engine valve that decelerates rotation and opens the valve against the spring force of the valve spring; and the electric motor; And a coupling mechanism that is provided between the control shaft and that transmits a rotational force to the control shaft and that is movable in a radial direction with respect to the axis of the control shaft. Is supplied to the joint mechanism while constantly circulating inside the speed reduction mechanism, and is discharged from the joint mechanism to the cylinder head side.

  According to the present invention, the radial vibration due to the alternating torque transmitted to the control shaft due to the spring force of the valve spring, etc. is transmitted to the joint mechanism, but the radial mobility of the joint mechanism is free. Thus, the vibration in the radial direction can be effectively absorbed.

As a result, since vibration transmission to the electric motor is reliably prevented, the driving load of the electric motor is reduced, and a smooth rotational driving force of the electric motor can be obtained.

In the invention described in claim 2, in particular, a joint mechanism between the electric motor and the control shaft that transmits rotational force to the control shaft and is movable in the radial direction with respect to the axis of the control shaft. And the lubricating oil is constantly supplied while circulating the ball bearing, the inner and outer teeth, and the joint mechanism.

According to the present invention, as described above, in addition to being able to absorb the vibration due to the alternating torque transmitted to the control shaft, the joint mechanism effectively absorbs the eccentric rotation of the power transmission member such as the planetary pinion gear and the ring gear. Thus, concentric rotation can be applied to the control shaft.

  Embodiments of a variable valve operating apparatus for an internal combustion engine according to the present invention will be described below in detail with reference to the drawings.

  In this embodiment, the variable valve device is applied to the intake valve side as in the prior art, and includes two intake valves per cylinder, and the valve lift amount and lift operating angle of the intake valve are determined in the engine operating state. It is designed to be variable according to.

That is, the variable valve operating apparatus in this embodiment includes a pair of intake valves 2 and 2 slidably provided on the cylinder head 1 via a valve guide (not shown) as shown in FIGS. includes a variable mechanism 3 that the valve lift amount variable control of the intake valves 2 and 2, the control mechanism 4 the operating position that Gyosu control of the variable mechanism 3, and an actuator 5 for rotating the control mechanism 4 Yes.

  As shown in FIG. 2, the intake valves 2 and 2 are valve springs elastically mounted between a bottom portion of a substantially cylindrical bore housed in an upper end portion of the cylinder head 1 and a spring retainer at the upper end portion of the valve stem. It is biased in the closing direction by 6 and 6 spring force.

  The variable mechanism 3 includes an internal hollow drive shaft 7 disposed in the longitudinal direction of the engine, and a camshaft 8 disposed for each cylinder and rotatably supported coaxially on the outer peripheral surface of the drive shaft 7. A drive cam 9 fixed at a predetermined position of the drive shaft 7 and a valve lifter 10 provided integrally at both ends of the camshaft 8 and disposed at the upper end of each intake valve 2, 2. 10 and a pair of oscillating cams 11 and 11 for slidingly opening the intake valves 2 and 2, and a driving cam 9 and the oscillating cams 11 and 11. Is transmitted as a swinging force (valve opening force) of the swinging cams 11, 11.

  The drive shaft 7 is disposed along the longitudinal direction of the engine, and both ends thereof are rotatably supported by bearings (not shown) provided at the top of the cylinder head 1 and are also provided at one end. Rotational force is transmitted from the crankshaft of the engine via an external driven sprocket and a timing chain wound around the driven sprocket.

  Each of the camshafts 8 is formed in a substantially cylindrical shape along the axial direction of the drive shaft 7, and a support shaft hole that is rotatably supported on the outer peripheral surface of the drive shaft 7 is formed through the inner shaft direction. At the same time, a cylindrical journal portion 8a formed at the central position is rotatably supported by a cam bearing integrally provided at the upper end portion of the bearing.

  The drive cam 9 is formed in a substantially disc shape, and as shown in FIG. 2, a fixing cylindrical portion 9 a is integrally provided on one side portion thereof, and this cylindrical portion 9 a is connected to the drive shaft 7. Is fixed integrally to the outer periphery of the drive shaft 7 through a fixing pin 12 at a predetermined position in the axial direction, and the outer peripheral surface is formed into an eccentric cam profile, so that the shaft center Y of the drive shaft 7 is It is offset from the shaft center X by a predetermined amount in the radial direction.

  As shown in FIGS. 1 to 3, the swing cams 11 have substantially the same raindrop shape, and the base end side swings about the axis X of the drive shaft 7 via the camshaft 8. In addition, a cam surface 11 a is formed on the lower surface of the swing cam 11.

  Further, on the cam nose portion 11b side of the swing cam 11, a pin hole through which a pin 18 connected to the other end portion 15b of the link rod 15 described later is inserted is formed to penetrate both sides.

  As shown in FIGS. 1 to 3, the transmission mechanism includes a rocker arm 13 disposed above the drive shaft 7, a link arm 14 linking the one end 13 a of the rocker arm 13 and the drive cam 9, and the rocker arm 13. Link rod 15 that links the other end portion 13b of this to the cam nose portion 11b of one of the swing cams 11 is provided.

  The rocker arm 13 is formed with a support hole 13c penetratingly formed in a central cylindrical base from the lateral direction, and is supported by a control cam 20 described later via the support hole 13c so as to be swingable. The one end portion 13a has a pin 16 integrally projecting from the side of the tip portion, while the other end portion 13b has a pin 17 connected to the one end portion 15a of the link rod 15 inside the tip portion. A pin hole to be inserted is formed.

  The link arm 14 includes an intermediate portion 14a having a relatively large diameter and a projecting end 14b projecting at a predetermined position on the outer peripheral surface of the intermediate portion 14a. The drive cam 9 is provided at a central position of the intermediate portion 14a. A fitting hole 14c is formed in the outer peripheral surface of the pin 16 so as to be freely rotatable, and a pin hole through which the pin 16 is rotatably inserted is formed in the protruding end 14b.

  The link rod 15 is integrally formed by press molding, the central portion is formed in a substantially U-shaped cross section, and the inside is bent into a substantially U-shape for compactness. Both end portions 15a and 15b are rotatably connected to the other end portion 13b of the rocker arm 13 and the cam nose portion 11b side of the swing cam 11 via the pins 17 and 18, respectively.

  As shown in FIGS. 1 to 3, the control mechanism 4 includes a control shaft 19 disposed above the drive shaft 7, and a swing fulcrum of the rocker arm 13 that is integrally fixed to the outer periphery of the control shaft 19. The control cam 20 is provided.

  The control shaft 19 is disposed in the longitudinal direction of the engine in parallel with the drive shaft 7 and is rotatably supported by a bracket provided at the upper end of the bearing shared with the camshaft 8. On the other hand, the control cam 20 has a cylindrical shape, and the axial center position is offset by a predetermined amount α from the axial center of the control shaft 19 by the thick portion.

  As shown in FIGS. 1 and 4 to 7, the actuator 5 is an electric motor that is a housing 21 fixed to the rear end portion of the cylinder head 1 and a rotational drive source fixed to one end wall 21 a of the housing 21. The motor 22 and a cycloid mechanism 23 that is provided inside the housing 21 and transmits a rotational driving force of the electric motor 21 to the control shaft 19 are configured.

  The housing 21 is formed in a cylindrical shape with a lid, and is arranged substantially coaxially with the axial direction of the control shaft 19, and rotatably supports a drive shaft 22 a that is an output shaft of the electric motor 22 at substantially the center of the one end wall 21 a. A support hole 21b for supporting the ball bearing 24 is formed so as to penetrate therethrough, and fixing bosses 21c to the rear end wall of the cylinder head 1 are integrally formed at four positions on the outer periphery. Further, a lubricating oil supply hole 21d for guiding the lubricating oil to the inside is formed at the upper end portion. A drain hole 1b for discharging the lubricating oil lubricated in the housing 21 is formed in the rear end wall 1a of the cylinder head 1.

  The electric motor 22 is constituted by a proportional type DC motor, and the front end portion of the motor casing is fixed to the one end wall 21a from the axial direction by a plurality of bolts 25, and the operation state of the engine is not shown. It is driven by a control signal from an electronic controller (ECU).

  This electronic controller includes various sensors such as a crank angle sensor that detects the engine speed, an air flow meter that detects the intake air amount, a water temperature sensor that detects the engine water temperature, and a potentiometer that detects the rotational position of the control shaft 19. The current engine operating state is detected by calculation and the like, and a control signal is output to the electric motor 22.

The cycloid mechanism 23 includes an eccentric cam 26 fixed to a drive shaft 22a of the electric motor 22, power transmission member having a sliding hole 27b slidably fitted on the outer peripheral surface of the eccentric cam 26 to the central there annular planetary pinion gear 27, is fixed by a plurality of bolts 29 in the housing 21, which is a non-rotating member that links so as to revolve and rotate the planetary pinion gears 27 on the inner circumferential side ring The gear 28 and the eccentric absorption means 30 for converting the eccentric rotation of the planetary pinion gear 27 into the concentric rotation and transmitting the rotation to the control shaft 19 are configured.

  As shown in FIGS. 4 and 6 to 8, the eccentric cam 26 is fixed at a position where its center Z1 is eccentric by a predetermined amount β from the axis Z of the drive shaft 22a, and the outer peripheral surface is formed in a substantially circular shape. ing.

  The eccentric cam 26 has an outer shape formed in an eccentric circular shape, and has a fixing hole 26a through which the drive shaft 22a is fixed at a position eccentric from the center.

  The planetary pinion gear 27 is supported by the eccentric cam 26 so as to be relatively rotatable by a ball bearing 31 provided between the outer peripheral surface of the eccentric cam 26 and the sliding hole 27b, and is disposed on the entire outer peripheral surface. External teeth 27a are formed.

  The ring gear 28 has an inner diameter that is set to be slightly larger than an outer diameter of the planetary pinion gear 27, and an inner tooth 28a that meshes with the outer teeth 27a of the planetary pinion gear 27 on the inner peripheral surface. The number of teeth of the inner teeth 28a is one more than the number of teeth of the outer teeth 27a. Thereby, the rotational speed of the electric motor 22 is decelerated.

  Further, between the control shaft 19 and the planetary pinion gear 27, the eccentric rotation of the planetary pinion gear 27 is converted into a concentric rotation while allowing the eccentric rotation of the planetary pinion gear 27, and this rotational force is applied to the control shaft 19. A joint mechanism 30 for transmission is provided.

  As shown in FIGS. 1, 4 and 7, the joint mechanism 30 is disposed on the front end face side of the eccentric cam 26, and the one end 19a of the control shaft 19 is loosely fitted in the central large-diameter hole 33a. A substantially annular intermediate portion 33 disposed between the pair of protrusions 34 and a pair of two-surface-width protruding portions 34 integrally protruding outward from the outer peripheral surface of the intermediate portion 33 along the diameter direction. , 34 and the one end surface of the planetary pinion gear 27 projecting at a 180 ° position in the diametrical direction, and while being fitted to the projecting portions 34, 34, are slidably guided in the longitudinal direction so that the planetary pinion gear 27 is In FIG. 7, a pair of bifurcated guide portions 35, 35 that allow movement in the vertical diameter direction, and guide pins that are inserted and fixed in fixing holes 19 b that are diametrically penetrated at one end portion 19 a of the control shaft 19. 36 and through from the direction perpendicular to both protrusions 34, 34 of the intermediate portion 33. Are formed, the both end portions slidably inserted into an intermediate portion 33 to the guide pins 36, in FIG. 7, and a sliding hole 37 Metropolitan to permit movement in the lateral direction. The projecting portions 34 and 34 and the guide portions 35 and 35 constitute a first movement allowance portion, and the guide pin 36 and the sliding holes 37 and 37 constitute a second movement allowance portion. . A cylindrical regulating portion 32 that regulates the movement of the intermediate portion 33 toward the one end portion 19 a is fixed to the one end portion 19 a side of the control shaft 19.

Therefore, when the planetary pinion gear 27 rotates eccentrically as shown in FIGS. 7 and 8, the guide portions 35, 35 slide in the radial direction along the projections 34, 34 of the annular portion 33. At the same time, the annular portion 33 is further slid in the radial direction of 90 ° via the guide pin 36, so that the rotational force is applied to the control shaft 19 via the annular portion 33 while allowing eccentric rotation of the planetary pinion gear 27. Is transmitted. That is, the rotational force due to the revolution and rotation accompanying the eccentric rotation of the planetary pinion gear 27 is transmitted from the guide portions 35 and 35 to the annular portion 33 through the projection portions 34 and 34, and further through the sliding holes 37 and 37. At this time, the annular portion 33 moves freely on the guide pin 36 in the radial direction and absorbs the eccentric rotation of the planetary pinion gear 27, while the planetary pinion gear is transferred to the guide pin 36. The rotation force of 27 is transmitted to rotate the control shaft 19.

  Further, as described above, the lubricating oil is supplied into the housing 21 from the lubricating oil supply hole 21d, and lubricates between the ball bearings 24 and 31 and the inner and outer teeth 27a and 28a while circulating through the inside. It is discharged from the drain hole 1b to a valve operating mechanism such as the variable mechanism 3.

  The operation of the present embodiment will be described below. First, for example, in the low rotation range of the engine, the electric motor 22 is rotationally driven by the control signal from the controller that detects this operating state, and the eccentric cam 26 rotates eccentrically. Then, the planetary pinion gear 27 rotates eccentrically in the reverse direction via the inner and outer teeth 27a and 28a meshing with the inner peripheral side of the ring gear 28 by this eccentric rotational force. That is, the planetary pinion gear 27 revolves while rotating around the drive shaft 22a in one direction.

  As a result, the intermediate portion 33 absorbs the eccentric rotation while freely moving in the radial direction via the guide pin 36 while being given the rotational force decelerated from the guide portions 35, 35 via the projections 34, 34. However, only the rotation of the planetary pinion gear 27 is applied to the control shaft 19 via the guide pin 36 in one direction.

  Accordingly, as the control shaft 19 rotates in one direction, the control cam 20 causes the shaft center P2 to rotate around the shaft center P1 of the control shaft 19 with the same radius as shown in FIGS. The thick part moves away from the drive shaft 7 upward. Thereby, the pivotal support point of the other end portion 13b of the rocker arm 13 and the link rod 15 moves upward with respect to the drive shaft 7, so that each swing cam 11 is connected to the cam nose portion 11b via the link rod 15. The side is forcibly raised.

  Therefore, when the drive cam 9 rotates and pushes up the one end portion 13a of the rocker arm 13 via the link arm 14, the valve lift amount is transmitted to the swing cam 11 and the valve lifter 10 via the link rod 15. The lift amount becomes sufficiently small.

  Therefore, in the low rotation region of such an engine, the valve lift amount L1 is minimized, so that the opening timing of each intake valve 2 is delayed, and the valve overlap with the exhaust valve is reduced. For this reason, improvement in fuel consumption and stable rotation of the engine can be obtained.

  On the other hand, when the engine shifts to the high rotation region, when the electric motor 22 rotates in the reverse direction by the control signal from the controller that detects this, and the eccentric cam 26 rotates in the same direction, the planetary pinion gear 27 and the ring gear 28 also rotate. The inner peripheral side of the shaft rotates in the opposite direction, and rotates around the drive shaft 22a while revolving in the other direction.

  As a result, the intermediate portion 33 receives the rotational force decelerated from the guide portions 35, 35 via the projections 34, 34, and moves the guide pin 36 while absorbing the eccentric rotation while freely moving in the radial direction. A rotational force in the other direction is applied to the control shaft 19 via the control shaft 19.

  Therefore, the control shaft 19 rotates the control cam 20 clockwise from the position shown in FIG. 9, and the axis P2 moves downward. For this reason, as shown in FIGS. 10A and 10B, the rocker arm 13 as a whole moves in the direction of the drive shaft 7, and the other end portion 13 b moves the cam nose portion 11 b of the swing cam 11 downward through the link rod 15. By pressing, the entire swing cam 11 is rotated counterclockwise by a predetermined amount.

  Therefore, the contact position of the cam surface 11a with respect to the upper surface of the valve lifter 10 of the swing cam 11 moves to the cam nose portion 11b side (lift portion side). For this reason, when the drive cam 9 rotates during the opening operation of the intake valve 2 and the one end 13a of the rocker arm 13 is pushed up via the link arm 14, the lift amount with respect to the valve lifter 10 becomes sufficiently large.

  Therefore, in such a high rotation region, the valve lift amount L2 is maximized, the opening timing of each intake valve 2 is advanced, and the closing timing is delayed. As a result, the intake charging efficiency is improved and a sufficient output can be secured.

  According to this embodiment, the radial vibration due to the alternating torque transmitted to the control shaft 19 due to the spring force of the valve spring or the like is transmitted to the intermediate portion 33 via the guide pin 36 of the joint mechanism 30. However, since the intermediate portion 33 freely moves in the radial direction through the guide pin 36 and the sliding holes 37, 37, it is possible to effectively absorb the vibration in the radial direction.

  As a result, vibration transmission to the cycloid mechanism 23 such as the planetary pinion gear 27 and the electric motor 22 is reliably prevented, so that the rotational driving load of the electric motor 22 is reduced and the electric motor 22 is always rotated smoothly. Driving force can be obtained.

  Further, since the joint mechanism 30 has a simple structure, as described above, it is possible to efficiently convert the eccentric rotation of the planetary pinion gear 27 to the concentric rotation, and to allow manufacturing errors of the respective components. It becomes possible to make it as small as possible. Further, since the joint mechanism 30 is downsized, the assembling property between the control shaft 19 and the planetary pinion gear 27 is also improved.

  Further, when the joint mechanism 30 is assembled to the control shaft 19 and the planetary pinion gear 27, the intermediate portion 33 is first linked to the guide pin 26 in the sliding holes 37, 37 and then assembled to the control shaft 19, Since the projections 34 and 34 are engaged with the guide portions 35 and 35 of the planetary pinion gear 27 so that the projections 34 and 34 are concavo-convexly fitted, the set-up of the assembling work becomes good and the assembling work becomes easy.

  In addition, since a part of the joint mechanism 30 is formed by the cylindrical guide pin 36 and the circular sliding holes 37, 37, it is possible to increase the processing accuracy thereof, and as a result, between the two, Generation of backlash can be suppressed.

  Further, according to this embodiment, the alternating torque is effectively absorbed by the joint mechanism 30 and is not transmitted to the cycloid mechanism 23, but even if it is slightly input to the planetary pinion gear 27. However, the planetary pinion gear 27 rotates eccentrically (revolves) and rotates while rolling on the inner peripheral side of the ring gear 28, so that the alternating torque at the portion meshed with the ring gear 28 is rotated in the positive and negative rotational directions. Interference is prevented. Therefore, it is possible to suppress the occurrence of abnormal noise.

  Further, since the eccentric cam 26 is accommodated in the sliding hole 27a of the planetary pinion gear 27 so as to be relatively rotatable, an alternating torque at the engaging portion of each ball and ball groove of the conventional ball screw transmission means is provided. The interference by does not occur.

  Further, since the lubricating oil in the housing 21 always supplies lubricating oil between the inner and outer teeth 27a and 28a of the planetary pinion gear 27 and the ring gear 28, the inter-tooth spaces 27a and 28a are sufficiently lubricated. Of course, the interference damper effect between the meshed inner and outer teeth 27a, 28a can be obtained.

  Further, in this embodiment, since the cycloid mechanism having a simple structure using the eccentric cam 26, the planetary pinion gear 27, and the ring gear 28 provided in the housing 21 is used, the entire apparatus can be reduced in weight and size. The mountability to the internal combustion engine is improved.

  In addition, the present invention is not limited to the configuration of the above-described embodiment. For example, the protrusions 34 and 34 and the guide portions 35 and 35 having a two-surface width in the first movement allowance portion are arranged in the respective circumferential directions. It is also possible to form three or more at the 90 ° position, or one.

  In addition to the electric motor 22, the rotational drive source may be a hydraulic motor or the like, and the inner and outer teeth 27a and 27a are not provided between the power transmission member and the non-rotating member. The surface can be formed in a simple circular shape, and the power transmission member can be revolved and rotated in the non-rotating member via a plurality of pins.

  Furthermore, each bearing can be replaced with a plain bearing instead of a ball bearing. Further, as a variable mechanism, the valve timing is variably controlled by rotating the control shaft 19 or only the valve lift amount is variably controlled. It can also be applied to things.

  Further, the joint mechanism 30 can be configured by an Oldham joint, a plurality of circular holes, and cylindrical protrusions that can be eccentrically inserted therein, in addition to those described in the above embodiment.

The technical ideas other than the invention described in the claims, as grasped from the embodiment, will be described below.
(1) The variable valve operating apparatus for an internal combustion engine according to any one of claims 1 to 3, wherein lubricating oil is supplied to the joint mechanism.

According to the present invention, lubricating oil enters between the constituent members of the joint mechanism to ensure the lubricity between the constituent members, and to exhibit the interference damper effect between the constituent members. Is possible. As a result, it is possible to prevent the generation of abnormal noise due to rattling between the constituent members.
(2) The first movement allowance part or the second movement allowance part is detachably linked to the control shaft or the power transmission member, and the other movement allowance part is connected to the control shaft or the power transmission on the other side. The variable valve operating apparatus for an internal combustion engine according to claim 3 or 1, wherein the variable valve is linked to a member in a non-detachable manner.

According to the present invention, the movement allowance portion on one side is detachably linked to the power transmission member, for example, by concavo-convex fitting from the radial direction, and the movement allowance portion on the other side is connected to the control shaft via a pin or the like, for example. When the joint mechanism is assembled to the control shaft and the power transmission member, the other side movement allowance portion is linked to the control shaft to a pin or the like first, and then the one side movement allowance portion is powered. Since the concave and convex portions can be fitted to the transmission member, the set-up of the assembling work becomes good and the assembling work becomes easy.
(3) The joint mechanism is formed in an intermediate portion inserted into an end portion of the control shaft and a two-sided width shape in a radial direction of the intermediate portion, and is axially connected to one of the control shaft or the power transmission member. The first movement-permitting part that is fitted and linked from the first part and the first movement-permitting part of the intermediate part are formed at a position substantially orthogonal to the other of the control shaft and the power transmission member from the radial direction. The second movement allowance unit linked together,
The second movement allowing portion is either a guide pin provided on either the other side of the control shaft or power transmission portion or the intermediate portion, or one of the other side of the control shaft or power transmission portion and the intermediate portion. The variable valve for an internal combustion engine according to claim 2, characterized in that the variable valve is provided with a sliding hole that is slidably guided in the radial direction through the guide pin. apparatus.

  According to the present invention, the joint mechanism is simple in structure and small in size, so that the manufacturing operation is facilitated and the assembly between the control shaft and the actuator is also good.

In addition, since the second movement allowing portion is formed by a cylindrical guide pin and a circular slide hole through which the guide pin is slidably inserted, it is possible to increase the processing accuracy thereof. The occurrence of backlash between the two can be suppressed.
(4) The variable valve operating apparatus for an internal combustion engine according to any one of claims 2 to 3, wherein the speed reduction mechanism is configured by a cycloid mechanism.
(5) The variable valve operating apparatus for an internal combustion engine according to any one of (1) to (4), wherein the variable mechanism variably controls a valve lift amount of the engine valve according to an engine operating state. .
(6) The variable valve for an internal combustion engine according to any one of (1) to (4), wherein the variable mechanism variably controls a phase of a lift center of the engine valve according to an engine operating state. apparatus.
(7) The internal combustion engine according to any one of (1) to (4), wherein the variable mechanism variably controls a valve lift and a lift operating angle of the engine valve according to an engine operating state. Variable valve gear.

It is a principal part disassembled perspective view which shows embodiment of the variable valve apparatus of this invention. It is a perspective view which shows the variable mechanism with which this embodiment is provided. It is a top view of the variable mechanism. It is sectional drawing of the actuator provided to this embodiment. It is a perspective view of the actuator. It is a front view of the actuator. It is a front view which shows the state which provided the eccentric absorption means in the cycloid mechanism of the actuator. It is a front view which shows the effect | action of the cycloid mechanism and eccentric absorption means of the actuator. A is an explanatory view showing a valve closing state during small lift control by a variable mechanism, and B is an explanatory view showing the valve opening state. A is an explanatory view showing a valve closing state during large lift control by a variable mechanism, and B is an explanatory view showing the valve opening state. It is a waveform characteristic view of the alternating torque transmitted to the control shaft due to the spring force of the valve spring.

Explanation of symbols

1 ... Cylinder head 2 ... Intake valve (engine valve)
DESCRIPTION OF SYMBOLS 3 ... Variable mechanism 4 ... Control mechanism 5 ... Actuator 6 ... Valve spring 21 ... Housing 22 ... Electric motor 23 ... Cycloid mechanism (deceleration mechanism)
26 ... Eccentric cam 27 ... Planet pinion gear (power transmission member)
28: Ring gear (non-rotating member)
DESCRIPTION OF SYMBOLS 30 ... Joint mechanism 33 ... Intermediate part 34 ... Projection part 35 ... Guide part 36 ... Guide pin 37 ... Sliding hole

Claims (2)

An electric motor that rotates according to engine operating conditions;
A speed reduction mechanism that reduces the rotation of the electric motor and transmits the rotational force to a control shaft that controls the valve timing by varying the phase of the lift center of the engine valve that opens against the spring force of the valve spring;
A joint mechanism that is provided between the electric motor and the control shaft, transmits a rotational force to the control shaft, and is movable in a radial direction with respect to the axis of the control shaft;
Lubricating oil supplied to the speed reduction mechanism is constantly supplied to the joint mechanism while circulating inside the speed reduction mechanism, and is discharged from the joint mechanism to the cylinder head side. Variable valve device. An electric motor that rotates according to engine operating conditions;
A rotational force is input from the electric motor, and an eccentric cam provided with an eccentric center with respect to the rotation center;
A planetary pinion gear having a sliding hole for accommodating the eccentric cam in the center and having external teeth formed on the entire outer peripheral surface;
A ball bearing provided between the eccentric cam and the sliding hole;
A ring gear having inner teeth formed on the inner periphery thereof that have more teeth than the outer teeth of the planetary pinion gear and mesh with the outer teeth of the planetary pinion gear;
As the electric motor rotates, the planetary pinion gear rotates and revolves inside the ring gear to rotate, thereby rotating the control shaft and opening the valve against the spring force of the valve spring by the rotation of the control shaft. The valve timing is controlled by making the phase of the lift center of the engine valve variable.
Provided between the electric motor and the control shaft is a joint mechanism that transmits rotational force to the control shaft and is movable in the radial direction with respect to the axis of the control shaft;
A variable valve operating apparatus for an internal combustion engine, characterized in that lubricating oil is constantly supplied while circulating through the ball bearing, the inner and outer teeth, and the joint mechanism.

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