JP2008202549A - Variable valve operating device for internal combustion engine - Google Patents

Abstract

The present invention provides a variable valve device that can suppress an increase in size and weight of a device by suppressing a rotational fluctuation torque acting on a control shaft and reducing a driving load of a drive mechanism.
A rocking force is transmitted from a drive cam 15 provided on the outer periphery of a drive shaft 13 via a rocker arm 23 as a transmission means, and a rocking cam 17 for opening and closing two intake valves 2 by this rocking force is provided. I have. The drive mechanism 6 controls the rotation of the control shaft 29 to change the rocking fulcrum of the rocker arm 23 via the control cam 30, thereby variably controlling the valve lift amount of each intake valve. A fan-shaped inertia mass body 31 that suppresses rotational fluctuation torque is provided in the vicinity of the bearing portion 14 on the drive mechanism side of the control shaft, and the drive shaft is disposed in a space below the fan-shaped inertia mass body 31.
[Selection] Figure 1

Description

  The present invention relates to a variable valve operating apparatus for an internal combustion engine that variably controls engine operating characteristics such as a valve lift amount and an operating angle of an engine valve that is, for example, an intake valve or an exhaust valve of the internal combustion engine according to an engine operating state.

  Various types of conventional variable valve operating apparatuses for internal combustion engines are provided, and one of them is disclosed in Patent Document 1 below, for example.

  In brief, this variable valve operating apparatus has two intake valves per cylinder, and includes a variable lift mechanism that variably controls the valve lift amount of each intake valve according to the engine operating state. Yes. This variable lift mechanism includes a transmission member disposed between each intake valve and each cam that opens and closes each intake valve on the camshaft, and an eccentric body having two cam profiles at a support point of the transmission member. And an eccentric shaft that is moved via

Then, the eccentric shafts are rotationally driven via an actuator according to the engine operating state to change the support point of the transmission member, thereby variably controlling the valve lift amounts of the two intake valves. Yes.
Japanese Patent Laid-Open No. 7-63023

  The eccentric shaft of the variable valve device in the prior art is subjected to rotational fluctuation torque from the camshaft due to the valve spring of each intake valve via the transmission member. Therefore, a relatively large rotational vibration (torsional vibration) is generated on the eccentric shaft, and this rotational vibration is transmitted to the actuator, increasing the rotational driving load of the actuator. As a result, the drive capacity of the actuator must be increased. Therefore, the actuator is forced to increase in size and weight, and the cost increases.

  In addition, the occurrence of the vibration makes it easy to generate hitting and wear between the constituent members of the actuator.

  The present invention has been devised in view of the actual state of the conventional variable valve operating apparatus. The invention according to claim 1 is a control shaft that is rotationally controlled according to an engine operating state, and the control shaft is rotated. It is characterized by comprising a variable mechanism that makes the operating characteristics of the engine variable by controlling, and an inertia mass body provided on the outer periphery of the control shaft in a state of being eccentric from the rotation center of the control shaft.

  Therefore, according to the present invention, for example, when rotational fluctuation torque is generated in the control shaft due to the spring force of the valve spring during engine operation, the rotational fluctuation torque is effectively absorbed by the inertia mass body and Vibration is reduced.

  Therefore, the driving load of the actuator that rotationally drives the control shaft can be reduced, and the increase in size of the actuator can be suppressed, and the occurrence of hitting sound and wear can also be suppressed.

  The invention according to claim 2 is a more specific embodiment of the invention according to claim 1, wherein the engine valve biased in the closing direction by the spring force of the valve spring and the eccentric control cam are integrally formed on the outer periphery. A control shaft provided, a variable mechanism that varies the operating characteristics of the engine valve by rotating the eccentric control cam by an actuator via the control shaft according to the engine operating state, and an outer periphery of the control shaft. And an inertial mass body provided in an eccentric state with respect to the rotation center of the control shaft.

  Therefore, this invention can achieve the same effects as those of the invention of the first aspect.

  The invention according to claim 3 is characterized in that the inertial mass body is disposed in the vicinity of a bearing portion bearing the control shaft.

  According to this invention, the rotational fluctuation torque acting on the control shaft is effectively absorbed by the inertia mass body, and vibration can be suppressed by the bearing portion. In particular, since the inertia mass body is disposed close to the bearing portion, the vibration suppressing effect can be further enhanced as compared with the case where the inertia mass body is separated.

  That is, the control shaft also generates radial bending vibration in addition to rotational vibration due to the rotational fluctuation torque. By adding a predetermined weight to the control shaft by an inertial mass body, the natural frequency decreases. This tends to increase bending vibration.

  Therefore, it is possible to suppress the vibration in the radial direction of the control shaft by arranging the inertia mass body in the vicinity of the bearing portion. As a result, it is possible to significantly reduce harmful vibration input to the actuator in combination with vibration absorption in the rotational direction by the inertial mass body.

  The invention described in claim 4 is characterized in that the inertia mass body is disposed between the eccentric control cam and the actuator.

  The rotational vibration of the control shaft accompanying the increase in the weight of the eccentric control cam can be absorbed by the inertia mass body, and the transmission to the actuator can be effectively cut off.

  According to a fifth aspect of the present invention, the inertial mass body is formed in a substantially annular shape, a notch is formed in a part of the inertial mass body in the circumferential direction, and another component member is provided in the notch. It is characterized in that a dispositionable void is formed.

  By forming the inertial mass body in a unique shape in this way, it is possible to avoid interference with another member arranged in the notch even if the inertial mass body rotates to the maximum. As a result, the apparatus can be made compact.

  The invention according to claim 6 is characterized in that the inertial mass body is provided on the control shaft via an elastic member.

  According to the present invention, for example, when an inertial mass body is divided in the radial direction and an elastic member is interposed therebetween, the control shaft system is determined from the difference in natural vibration between the inner inertial mass part and the outer inertial mass part. A large vibration acceleration level based on the natural frequency can be suppressed.

  According to a seventh aspect of the present invention, an arm portion for transmitting the driving rotational force of the actuator to the control shaft is provided at an end portion of the control shaft, and the inertia mass body is integrally provided on the arm portion. It is characterized by.

  According to the present invention, since the inertia mass body is provided using the arm portion, a special space for providing the inertia mass body is not required.

  In addition, since the control shaft and inertial mass body are integrally formed with the arm, the fastening rigidity between the control shaft and inertial mass body is increased, and harmful vibration input (fastening looseness, etc.) coming from the control shaft is inertial mass. It is possible to prevent the body from efficiently absorbing and transmitting to the actuator side via the arm portion.

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.
[First embodiment]
First, in the first example, the variable valve system is applied to the intake side of a V-type six-cylinder internal combustion engine, and the drawing of this embodiment shows a case where it is applied to one side three cylinders.

  That is, as shown in FIGS. 1 to 5, the variable valve operating device is slidably provided on the cylinder head 1 via a valve guide (not shown) and is urged in the closing direction by the valve springs 3 and 3. In addition, two intake valves 2, 2 per cylinder, a variable mechanism 4 that variably controls the valve lift amount of each intake valve 2, 2, a control mechanism 5 that controls the operating position of the variable mechanism 4, and the control And a drive mechanism 6 that is an actuator that rotationally drives the mechanism 5.

  The variable mechanism 4 includes a hollow drive shaft 13 rotatably supported by a bearing portion 14 provided on an upper portion of the cylinder head 1, a drive cam 15 fixed to the drive shaft 13 by a fixing pin, a drive One intake valve 2, 2 is opened by slidingly contacting the upper surface of the valve lifters 16, 16 supported on the outer circumferential surface of the shaft 13 and disposed at the upper end of each intake valve 2, 2. Transmission that transmits the rotational force of the drive cam 15 as the swinging force of the swing cams 17, 17 linked to the two swing cams 17, 17 per cylinder and between the drive cam 15 and the swing cams 17, 17. Means.

  The drive shaft 13 is disposed along the longitudinal direction of the engine, and is driven from a crankshaft of the engine via a driven sprocket (not shown) provided at one end and a timing chain wound around the driven sprocket. A rotational force is transmitted, and the direction of rotation is set in the direction of the arrow in FIG.

  As shown in FIG. 4A, the bearing portion 14 is provided at the upper end portion of the cylinder head 1 and supports the upper portion of the drive shaft 13, and is provided at the upper end portion of the main bracket 14a and is described later. The sub bracket 14b rotatably supports the shaft 32, and both the brackets 14a and 14b are fastened together by a pair of bolts 14c and 14c from above. The bearing portion 14 is provided for each cylinder and is also disposed in the vicinity of the drive mechanism 6.

  The drive cam 15 has a substantially ring shape, and includes an annular cam main body and a cylindrical portion integrally provided on the outer end surface of the cam main body, and a drive shaft insertion hole is formed through the inner shaft. In addition, the axis Y of the cam body is offset from the axis X of the drive shaft 13 in the radial direction by a predetermined amount. The drive cam 15 is fixed to the drive shaft 13 through a drive shaft insertion hole at a position where it does not interfere with the valve lifters 16 and 16, and the outer peripheral surface of the cam body has an eccentric circular cam profile. Is formed.

  Each of the swing cams 17 has a substantially raindrop shape of the same shape, is integrally provided at both ends of the cylindrical member 20, and the cylindrical member 20 is rotatably fitted to the outer peripheral surface of the drive shaft 13. And is supported. Each swing cam 17 is formed with a pin hole penetrating on the cam nose 21 side of each tip, and a cam surface 22 is formed on each lower surface. The cam surface 22 includes a base circle surface on the cylindrical member 20 side, a ramp surface extending in an arc from the base circle surface to the cam nose portion 21 side, and a peak of the maximum lift that the cam surface nose portion 21 has from the ramp surface. A lift surface that is continuous with the surface is formed, and the base circle surface, the ramp surface, and the lift surface come into contact with predetermined positions on the upper surface of each valve lifter 16 according to the swing position of the swing cam 17. Yes.

  The transmission means includes a rocker arm 23 disposed above the drive shaft 13 for each cylinder, a link arm 24 that links each end portion 23a of each rocker arm 23 and each drive cam 15, and a rocker arm 23. The other end portion 23b of the first and second rocking cams 17 are linked to each other.

  The rocker arm 23 is rotatably supported by a control cam 30 (to be described later) through a support hole 23c formed inside a cylindrical base portion at the center. Further, the one end 23a projecting in one direction from the cylindrical base is formed with a pin hole through which the pin 26 is inserted, while the other end projecting in the other direction of the cylindrical base. 23b has a pin hole into which a pin 27 connected to one end of the link rod 25 is inserted.

  The link arm 24 includes an annular base 24a having a relatively large diameter and a projecting end 24b projecting at a predetermined position on the outer peripheral surface of the base 24a. The drive cam 15 is located at the center of the base 24a. A fitting hole 24c is formed in which the cam body is rotatably fitted, and a pin hole through which the pin 26 is rotatably inserted is formed in the protruding end 24b.

  The link rod 25 is formed in a substantially rectangular shape having a concave shape on the rocker arm 23 side, and is inserted into each pin hole of the other end portion 23b of the rocker arm 23 and the cam nose portion 21 of the swing cam 17 at both end portions 25a and 25b. Pin insertion holes through which end portions of the pins 27 and 28 are rotatably inserted are formed.

  A snap ring for restricting the movement of the link arm 24 and the link rod 25 in the axial direction is provided at one end of each pin 26, 27, 28.

  The control mechanism 19 is integrally provided on the outer peripheral surface of the control shaft 29 and the control shaft 29 rotatably supported by the same bearing portion 14 at the upper position of the drive shaft 13, and the cylindrical shape of the rocker arm 23 described above. A control cam 30, which is an eccentric cam that is slidably fitted into a support hole 23 c in the base portion and serves as a rocking fulcrum of the rocker arm 23.

  As shown in FIG. 4A, the control shaft 29 is arranged in the longitudinal direction of the engine in parallel with the drive shaft 13, and the journal portion at a predetermined position is formed between the main bracket 14a and the sub bracket 14b of the bearing portion 14. The bearing is rotatably supported between them.

  The control cam 30 is provided in each cylinder, that is, in each rocker arm 23 and is formed in a substantially eccentric annular shape, and the position of the axis P2 is offset from the axis P1 of the control shaft 29 by a predetermined amount.

  An inertia mass body 31 is provided at the end of the control shaft 29 on the drive mechanism 6 side.

  The inertia mass body 31 is disposed in the vicinity of the bearing portion 14 provided between the first cylinder and the drive mechanism 6, and between the control cam 30 and the bearing portion 14 on the first cylinder side. As shown in FIGS. 1 and 3, the entire structure is formed in a plate-like fan shape (semicircular shape), and the main part 31 a is fitted to the outer peripheral surface of the control shaft 29. The outer peripheral portion 31b having an arc shape is formed thicker than the inner peripheral portion 31c. The main part 31 a is fixed to the specific position on the outer periphery of the control shaft 29 by a screw 32 screwed into a female screw hole formed in the inner radial direction.

  Further, as described above, the inertia mass body 31 is formed in a semicircular shape having a notch formed at the lower end portion, and the drive shaft 13 is disposed in a gap formed by the notch, and the entire maximum rotation is achieved. The angle is about 90 degrees, which is the same as the maximum normal / reverse angle of the control shaft 29 (range from the solid line to the one-dot chain line in FIG. 3), and is arranged so as not to interfere with the drive shaft 13 within this rotational angle range. .

The drive mechanism 6 includes an electric motor 34 provided in a motor housing 33 fixed to the rear end portion of the cylinder head 1, and a speed reducer 35 that decelerates the rotation of the electric motor 34 and transmits it to the control shaft 29. The electric motor 34 is composed of a proportional DC motor, and is driven by a control signal from a control unit 36 for detecting the driving state of the engine, as shown in FIG. The reduction gear 35 is formed in a multi-stage gear type formed by meshing a plurality of gears.

  The control unit 36 feeds back detection signals from various sensors such as a crank angle sensor, an air flow meter, a water temperature sensor, and a potentiometer 37 that detects the rotational position of the control shaft 29, and the current engine operation is not shown. The state is detected by calculation or the like, and a control current is output to the electric motor 34.

  Hereinafter, the operation of the present embodiment will be described. First, for example, in the low rotation operation region including the idling operation of the engine, the rotational force transmitted to the electric motor 34 by the control current from the control unit 36 is decelerated. 4 is transmitted from the machine 35 to the control shaft 29, and the control shaft 29 is rotationally driven clockwise as shown in FIGS. 4A and 4B.

  As a result, the control cam 30 rotates the shaft center P2 around the axis P1 of the control shaft 29 with the same radius, as shown in FIGS. Moving. As a result, the other fulcrum 23b of the rocker arm 23 and the pivot point of the link rod 25 move upward with respect to the drive shaft 13, so that each swing cam 17 is connected to the cam nose portion 21 via the link rod 25. The side is forcibly pulled up and the whole is rotated clockwise.

  Therefore, when the drive cam 15 rotates and pushes up the one end portion 23a of the rocker arm 23 via the link arm 24, the cam lift amount is transmitted to the swing cam 17 and the valve lifter 16 via the link rod 25. The lift amount becomes smaller.

  Therefore, in the low rotation region of such an engine, the valve lift amount becomes the smallest as shown by L1 in FIG. 6A, so that the opening timing of each intake valve 2 is delayed and the valve overlap with the exhaust valve is small. Become. For this reason, improvement in fuel consumption and stable rotation of the engine can be obtained.

  When the engine is shifted to the high engine speed region, the electric motor 34 is rotated in reverse by the control signal from the control unit 36, and this rotational force is transmitted to the control shaft 29 via the speed reducer 35. Then, the control cam 30 is rotated clockwise from the position shown in FIG. 4, and the axis P2 is rotated downward as shown in FIGS. 5A and 5B. For this reason, the rocker arm 23 is now moved toward the drive shaft 13 in its entirety, and the other end 23b presses the cam nose portion 21 of the swing cam 17 downward via the link rod 25, thereby moving the swing cam. 17 is rotated counterclockwise by a predetermined amount.

  Therefore, when the drive cam 15 rotates and pushes up the one end portion 23a of the rocker arm 23 via the link arm 24, the cam lift amount is transmitted to the swing cam 17 and the valve lifter 16 via the link rod 25. The lift amount becomes large.

  Therefore, in such a high rotation region, the valve lift amount of each intake valve 2 is maximized as indicated by L2 in FIG. 6A, and 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.

  When the rotational fluctuation torque is generated from the drive shaft 13 to the control shaft 29 via the transmission means due to the spring force of each valve spring 3, the rotational fluctuation torque is effectively absorbed by the inertia mass body 31. Is done. As a result, vibration in the rotational direction of the control shaft 29 is reduced.

  That is, as shown in FIG. 6B, the control shaft 29 in the vicinity of the drive mechanism 6 in the conventional case without the inertia mass body 31 (one-dot chain line) and in the case of the present embodiment with the inertia mass body 31 (solid line). Comparing torque fluctuations, it is clear that the peak torque at the time of the high lift (during high engine rotation) is greatly reduced.

  Therefore, the drive load of the speed reducer 35 and the electric motor 34 that are the drive mechanism 6 that rotationally drives the control shaft 29 is reduced, and the enlargement of the electric motor 34 can be suppressed, and the components of the drive mechanism 6 can be reduced. It is also possible to suppress the occurrence of hitting sound and wear.

  Further, in this embodiment, the inertial mass body 31 is disposed close to the bearing portion 14 on the drive mechanism 6 side, so that the rotational fluctuation torque acting on the control shaft 29 is effectively reduced by the inertial mass body 31. In addition to being absorbed, the bearing portion 14 can suppress bending vibration.

  That is, the control shaft 29 also generates a bending vibration in the radial direction in addition to the rotational vibration due to the rotational fluctuation torque. By adding a predetermined weight to the control shaft 29 by the inertia mass body 31, the natural frequency is increased. Tends to cause an increase in bending vibration.

  Thus, by arranging the inertial mass body 31 in the vicinity of the bearing portion 14 as in the present embodiment, it is possible to effectively suppress the bending vibration in the radial direction of the control shaft 29. As a result, coupled with the vibration absorption in the rotational direction by the inertial mass body 31, it is possible to significantly reduce harmful vibration input to the drive mechanism 6.

  Further, since the inertial mass body 31 is disposed between the control cam 30 and the drive mechanism 6, the inertial mass body 31 absorbs the rotational vibration of the control shaft 29 accompanying the increase in the weight of the control cam 30. The transmission to the drive mechanism 6 can be effectively cut off.

Furthermore, by forming the inertial mass body 31 in a unique fan shape, it is possible to avoid interference of the drive shaft 13 disposed in the gap even if the inertial mass body 31 rotates to the maximum. As a result, the apparatus can be made compact.
[Second Embodiment]
7A and 7B show a second embodiment, in which the outer peripheral portion 31b of the inertial mass body 31 is divided in the radial direction, and a rubber material 33, which is an elastic member, is interposed between the inner and outer peripheral surfaces of the divided portions. ing. The rubber material 33 is formed in a substantially curved plate shape, and is set to a length substantially the same as the circumferential length of the outer peripheral portion 31b, and the width length is also substantially the same as the width length of the outer peripheral portion 31b. Is set. Therefore, the inertia mass body 31 functions as a dynamic damper by the rubber material 33. Other configurations and the arrangement configuration of the inertia mass body 31 are the same as those in the first embodiment.

Therefore, in addition to the operational effects of the first embodiment, as shown in FIG. 8, the vibration acceleration level (dB) in the relationship of the vibration frequency acting on the control shaft 29 can be effectively reduced. That is, when the vibration acceleration level is compared with the case where the inertial mass body 31 is provided as in this embodiment (solid line) and the case where it is not provided (one-dot chain line), the case of this embodiment is better. It is clear that it is greatly reduced. That is, a peaky vibration acceleration level based on the natural frequency of the control shaft 29 system can be suppressed from the difference in natural vibration between the outer portion and the inner portion (including the inner peripheral portion 31c) of the outer peripheral portion 31b. This is because the function of the rubber member 33 as a dynamic damper is sufficiently exhibited.
[Third embodiment]
FIGS. 9 and 10 show a third embodiment in which the structure of the drive mechanism 6 is changed, and a ball screw mechanism 38 is used as a speed reducer.

  That is, the drive mechanism 6 includes a DC type electric motor 34 provided at one end of a housing (not shown) and a ball screw provided inside the housing to transmit the rotational driving force of the electric motor 34 to the control shaft 29. And a mechanism 38.

  The ball screw transmission mechanism 38 includes a ball screw shaft 39 disposed coaxially with the drive shaft of the electric motor 34 in the housing, and a ball nut 40 that is a moving nut screwed onto the outer periphery of the ball screw shaft 39. The control arm 29 is mainly composed of a linkage arm 41 which is an arm portion connected to one end portion of the control shaft 29 along the diametrical direction, and a link member 42 which links the linkage arm 41 and the ball nut 40.

  The ball nut 40 is applied with a moving force in the axial direction while converting the rotational motion of the ball screw shaft 39 into a linear motion via each ball.

  One end of the linkage arm 41 is integrally connected to the end of the control shaft 29 by welding or the like, and the inertia mass body 31 is integrally provided at the outer end of the one end. The inertial mass body 31 is disposed on the opposite side of the linkage arm 41 with the control shaft 29 interposed therebetween, and the main portion 31a is not cylindrical and is integrally coupled to the linkage arm 41, and the other outer peripheral portion 31b or The inner peripheral part 31c is the same as the structure of the first embodiment.

  Therefore, according to this embodiment, the forward or reverse rotational torque transmitted to the electric motor 34 by the control current from the control unit 38 according to the engine operating state as described above is transmitted to the ball screw shaft 39. Then, when the ball rotates, the ball nut 40 moves linearly in one direction while rolling between the ball circulation groove and the guide groove.

  As a result, the control shaft 29 is driven to rotate clockwise or counterclockwise by the link member 42 and the linkage arm 41 as shown in FIGS. 4 and 5 described above, and performs the same operation as in the first embodiment. .

  According to this embodiment, the inertial mass body 31 is provided by using the linkage arm 41 as well as the effects of the first embodiment. No special space is required for installation.

  In addition, since the control shaft 29 and the inertia mass body 31 are integrally formed with the linkage arm 41, the coupling rigidity between the control shaft 29 and the inertia mass body 31 is increased, and harmful vibration input from the control shaft 29 is generated. Can be efficiently absorbed by the inertial mass body 31 and transmitted to the drive mechanism 6 side via the linkage arm portion 41 can be suppressed.

  In addition, as an application target of the inertial mass body 31 in the present invention, it can be applied to a control shaft of a compression ratio variable mechanism of an internal combustion engine described in, for example, JP-A-2005-351280.

  11A to 11C, the compression ratio variable mechanism has a connecting rod 50 formed in a vertically divided structure, and an upper connecting rod 50 a and a lower connecting rod 50 b are connected by a link 51. The lower end of the upper connecting rod 50a is link-supported by a support arm 52 so that the piston 53 is moved up and down in a state where the entire connecting rod is bent into a substantially U shape. By changing the bending degree of the connecting rod 50, the height of the crown portion of the piston 53 is changed, and the volume of the combustion chamber 54 at the piston top dead center position is changed, so that the compression ratio is also changed. The degree of bending is adjusted by supporting the swing fulcrum of the support arm 52 by a control shaft 55 having an eccentric cam and changing the support point. That is, by rotating the control shaft 55, the bending degree of the connecting rod 50 is changed via the eccentric cam 56, and the compression ratio of the engine is continuously changed.

  Since the inertia force generated by the reciprocating motion of the piston 53 and the connecting rod 50 acts on the control shaft 55 via the upper connecting rod 50a and the support arm 52, the control shaft 55 rotates as in the previous embodiments. Vibration occurs.

  Therefore, by disposing the inertial mass body 31 between the support arm 52 and the actuator 57 of the control shaft 55, the rotational vibration of the control shaft 55 is absorbed, and the generation of vibration and the components of the actuator 57 are Wear can be prevented.

  In FIG. 11, 58 is an intake valve that is opened by rotation of a drive cam provided on the intake camshaft 59, and 60 is an exhaust valve that is opened by rotation of a drive cam provided on the exhaust camshaft 61.

  The present invention is not limited to the configuration and application target of each of the above-described embodiments. For example, the structure and arrangement position of the inertial mass body can be arbitrarily set according to the application device.

It is a principal part perspective view which shows the 1st Example of the variable valve apparatus which concerns on this invention. It is a principal part side view of the variable valve apparatus of a present Example. It is a side view which shows the arrangement | positioning relationship between the control shaft provided to a present Example, an inertia mass body, and a drive shaft. 1A is a view as viewed in the direction of the arrow A in FIG. 1 showing the valve closing action during the minimum lift control in the variable valve operating apparatus, and B is a view taken in the direction of the arrow A in FIG. 1A is a view as viewed from an arrow A in FIG. 1 showing a valve closing action at the time of maximum lift control in the variable valve operating apparatus, and B is a view as seen from an arrow A of FIG. A is a valve lift characteristic diagram of the intake valve according to the present embodiment, and B is a characteristic diagram comparing torque fluctuations of the control shaft in the conventional and the present embodiment. The principal part of the variable valve apparatus of 2nd Example is shown, A is a partial cross section figure of an inertial mass body, B is a side view of an inertial mass body. It is a characteristic figure which compared the vibration acceleration level in a prior art example and a present Example. It is a principal part side view of the variable valve apparatus of a 3rd Example. It is a principal part side view, such as a ball screw mechanism and an inertial mass body which are provided to a present Example. 1 shows an embodiment in which the present invention is applied to a variable compression ratio mechanism of an internal combustion engine, wherein A is a low compression state, B is a high compression state, and C is a side view of the main part.

Explanation of symbols

2 ... Intake valve (engine valve)
DESCRIPTION OF SYMBOLS 4 ... Variable mechanism 5 ... Control mechanism 6 ... Drive mechanism 13 ... Drive shaft 14 ... Bearing part 15 ... Drive cam 17 ... Swing cam 23 ... Rocker arm 29 ... Control shaft 30 ... Control cam (eccentric control cam)
DESCRIPTION OF SYMBOLS 31 ... Inertial mass 31a ... Essential part 31b ... Outer peripheral part 31c ... Inner peripheral part 33 ... Rubber material (elastic member)

Claims (7)

A control shaft that is rotationally controlled according to engine operating conditions;
A variable mechanism for varying the operating characteristics of the engine by controlling the rotation of the control shaft;
An inertia mass body provided on the outer periphery of the control shaft in an eccentric state from the rotation center of the control shaft;
A variable valve operating apparatus for an internal combustion engine, comprising: An engine valve biased in the closing direction by the spring force of the valve spring;
A control shaft integrally provided with an eccentric control cam on the outer periphery;
A variable mechanism that varies the operating characteristics of the engine valve by rotationally controlling an eccentric control cam via the control shaft by an actuator according to an engine operating state;
An inertia mass body provided on the outer periphery of the control shaft in an eccentric state from the rotation center of the control shaft;
A variable valve operating apparatus for an internal combustion engine, comprising: The variable valve operating apparatus for an internal combustion engine according to claim 1 or 2, wherein the inertia mass body is disposed in the vicinity of a bearing portion for bearing the control shaft. 4. The variable valve operating apparatus for an internal combustion engine according to claim 2, wherein the inertia mass body is disposed between the eccentric control cam and the actuator. The inertial mass body is formed in a substantially annular shape, a notch is formed in a part of the inertial mass body in the circumferential direction, and a void portion in which another component member can be disposed in the notch is formed. The variable valve operating apparatus for an internal combustion engine according to any one of claims 1 to 4, wherein: The variable valve operating apparatus for an internal combustion engine according to any one of claims 1 to 5, wherein the inertia mass body is provided on the control shaft via an elastic member. 7. An arm portion for transmitting a driving rotational force of the actuator to the control shaft is provided at an end portion of the control shaft, and the inertia mass body is provided integrally with the arm portion. The variable valve operating apparatus for an internal combustion engine according to any one of the above.

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