JP4499142B2 - Variable valve gear for internal combustion engine and support mechanism for variable valve gear - Google Patents

Description

  The present invention relates to a variable valve operating apparatus for an internal combustion engine that can variably control the opening / closing timing and valve lift amount of an intake valve or exhaust valve, which is an engine valve, according to the engine operating state, and the variable valve operating apparatus.

  As is well known, the intake / exhaust valve opening / closing timing is required to improve fuel efficiency at low engine speeds and low loads, to ensure stable operation, and to ensure sufficient output by improving intake charging efficiency at high speeds and high loads. Various valve operating devices that variably control the valve lift amount according to the engine operating state have been provided, and for example, those described in the following Patent Document 1 previously filed by the applicant of the present application. Are known.

  Briefly, two intake valves per cylinder that are slidably provided on the cylinder head and open and close the intake port, and provided at the upper end of the cylinder head along the longitudinal direction of the engine, and on the outer periphery of the rotating cam Are integrally mounted, a control shaft that is disposed substantially parallel to the upper position of the drive shaft, and a control cam that is integrally provided on the outer periphery, and rotation of the control cam causes the engine valve to An operation mechanism for controlling the operation, and an actuator for rotating the control shaft in a predetermined angle range according to an engine operating state, wherein the drive shaft and the control shaft are supported by an upper end portion of a cylinder head. It is rotatably supported by the mechanism.

  The drive shaft is driven to rotate by a crankshaft of the engine, and the control shaft is controlled to be rotated by an electric actuator that rotates forward and backward by a control signal from a controller that detects the engine operating state. It has become.

  The actuating mechanism is supported by a pair of swing cams that slide on the upper end portion of each intake valve to open and close the intake valve, and the center is swingably supported by the control cam, and one end portion is a link. The rocker arm is linked to the rotary cam via an arm and the other end is linked to the swing cam via a link member.

  The support mechanism includes a main bracket provided on an upper end surface of the cylinder head and a sub bracket provided on an upper portion of the main bracket. The main bracket is located at a substantially central position of the lower surface of the cylinder head. A semicircular support groove for bearing the drive shaft is formed in cooperation with a semicircular support groove formed on the upper end surface, and a small-diameter semi-groove formed on the lower surface of the sub bracket on the upper surface. A semicircular bearing groove that rotatably supports the control shaft is formed in cooperation with the circular bearing groove.

  For example, when the engine is running at low speed and low load, the electric actuator is rotated by the control signal from the controller to control the rotational position of the control shaft in one direction, so that the control cam is rotated and the entire rocker arm is moved from the drive shaft. Move away diagonally upward and pull up the cam nose of each rocking cam.

  For this reason, control is performed so as to reduce the valve lift amount for each intake valve by each swing cam, and the opening timing is delayed to reduce the valve overlap with the exhaust valve. As a result, fuel consumption can be improved and engine rotation can be stabilized.

  On the other hand, when the engine high-speed and high-load range is entered, the controller controls the rotation of the control shaft in the opposite direction to that described above via the electric actuator and controls the rotation of the control cam in the opposite direction. As a result, the entire rocker arm is moved obliquely downward toward the drive shaft, and the cam nose portion of each swing cam is lowered.

For this reason, control is performed to increase the valve lift amount for each intake valve by each swing cam, and control is performed to advance the opening timing and delay the closing timing. As a result, the intake charging efficiency is improved and a sufficient output torque can be secured.
Japanese Patent Laid-Open No. 1-107725

  However, in the conventional variable valve device, although the support mechanism supports the drive shaft and the control shaft in common, a support groove for bearing the lower portion of the drive shaft is formed on the upper surface of the cylinder head. Therefore, when assembling each component of the operating mechanism on the cylinder head, the drive shaft, the control shaft, the rotating cam, and the like must be separately assembled.

  That is, the control shaft can be supported in advance between the main bracket and the sub bracket of the support mechanism, and components such as the control cam and the rocker arm can be assembled, but the drive shaft is not directly supported by the support mechanism. The main bracket of the support mechanism is then placed on the upper surface of the cylinder head while the support groove is fitted to the upper end of the drive shaft. Thereafter, the entire components of the control shaft, the drive shaft, and the operating mechanism are assembled on the cylinder head by bolts.

  For this reason, the assembling work of the respective components of the drive shaft, the control shaft, and the operating mechanism becomes complicated, resulting in a decrease in the assembling work efficiency and an increase in cost.

  Further, since the lower part of the drive shaft is supported by a support groove formed on the upper surface of the cylinder head, a so-called centering between the two axes of the drive shaft and the control shaft supported by the support mechanism is performed. As a result, the accuracy may decrease, and as a result, the valve lift amount of each intake valve for each cylinder may vary. That is, normally, the drive shaft and the control shaft are centered after each component is assembled to the cylinder head by the support mechanism, and the control shaft is performed in a state of being supported between the main bracket and the sub bracket. The drive shaft is supported in a state where it is supported between the cylinder head and the main bracket. However, since the upper surface of the cylinder head is not sufficiently accurate in the first place, the accuracy of the support groove formed based on this upper surface is sufficient. It cannot be secured. Therefore, since high-precision centering between the two shafts cannot be obtained, there is a possibility that the operation of each operation mechanism varies and the valve lift amount varies.

The present invention has been devised in view of the problems of the conventional variable valve gear, and the invention according to claim 1 comprises a drive shaft that is rotationally driven by a crankshaft and provided with a rotating cam on the outer periphery,
A swing cam that swings by rotation of the rotary cam to open and close the engine valve;
A control shaft that is driven to change the lift position of the engine valve by changing the swing position of the swing cam;
An actuator comprising: an electric motor; and a transmission mechanism having a sliding portion that slides in the axial direction by the rotational force of the electric motor; and an actuator configured to link the sliding portion and the control shaft;
A pair of vertical beam portions facing each other across the cylinders, provided between the vertical beam portions, each horizontal beam portion arranged between the cylinders, and provided between the vertical beam portions, the transmission And an end wall portion through which a hole for transmitting power from the mechanism to the control shaft is formed, and the drive shaft and the control shaft are supported by a bracket fixed to each lateral beam portion with a bolt. A support mechanism,
The actuator is integrally fixed to the end wall portion, and the support mechanism is detachably provided to the cylinder head ,
The transmission mechanism is housed and held in a case cover, the electric motor is fixed to the case cover, and the case cover is fixed to the end wall portion .

  Therefore, according to the present invention, the drive shaft is not directly supported by the cylinder head, but is supported by the support mechanism in the same manner as the control shaft, that is, the bearing is supported between the support and the main bracket. Since the drive shaft can be assembled to the support mechanism in advance, the entire components of the operating mechanism can also be assembled to the support mechanism in advance to form a unit. Therefore, the assembly work to the cylinder head becomes extremely easy.

  Moreover, since the drive shaft and the control shaft can be supported by the same support mechanism, the centering operation of both shafts is facilitated, and high centering accuracy can be ensured.

Hereinafter, each reference example and embodiment concerning the present invention are explained in full detail based on a drawing. In this reference example and the embodiment, the present invention is applied to a V-type 6-cylinder internal combustion engine having two intake valves per cylinder, and one of the three cylinders is shown in each drawing.

1 to 3 show a first reference example of the present invention. This variable valve operating apparatus is a pair of intake valves 2 and 2 slidably provided on a cylinder head 1 via a valve guide (not shown). A hollow drive shaft 3 disposed above the cylinder head 1 in the longitudinal direction of the engine, two eccentric cams 4 and 4 which are rotary cams fixed to the drive shaft 3 by press fitting, A control shaft 5 that is rotatably supported at an upper position of the drive shaft 3 and has a control cam 6 press-fitted and fixed to the outer periphery; an operation mechanism 7 that controls the operation of each intake valve 2 by the rotation of the control cam 6; An electric motor (not shown) that is an actuator that rotates the control shaft 5 in a predetermined angle range according to the engine operating state. The drive shaft 3 and the control shaft 5 are connected to the upper end surface 1a of the cylinder head 1. Is supported rotatably by a support mechanism 9 attached to the .

  As shown in FIG. 3, each intake valve 2 is in contact with the stem end at one end of a follower member 11 that is swingably supported by a pivot 10, and the other end of the follower member 11 is pivoted to a pivot 12. Abutment is supported.

  The drive shaft 3 is arranged along the longitudinal direction of the engine, and is rotated from the crankshaft of the engine via a driven sprocket (not shown) provided at one end, a timing chain wound around the driven sprocket, and the like. Power is transmitted.

  The eccentric cam 5 is formed in a circular shape and has an insertion hole through which the drive shaft 3 is inserted and press-fitted in the inner axial direction. The shaft center X extends from the axis Y of the drive shaft 3 in the radial direction. Offset by a predetermined amount.

  The control shaft 5 is disposed above the drive shaft 3 in parallel with the drive shaft 3, while the control cams 6 each have a cylindrical shape and are fixed to the outer periphery of the control shaft 5. As shown in FIG. 3, the position of the shaft center P1 is deviated from the shaft center P2 of the control shaft 5 by a predetermined amount.

  As shown in FIGS. 1 to 6, the support mechanism 9 includes a support 13 that is detachably provided on the upper end surface 1 a of the cylinder head 1, and a main bracket that is detachably provided on the top of the support 13. 14, a sub bracket 15 that is detachably provided on the upper portion of the main bracket 14, and a connection that couples the support 13, the main bracket 14, and the sub bracket 15 together on the cylinder head 1 together in the vertical direction. It is mainly composed of means.

  As shown in FIGS. 1, 2, and 4, the support 13 is formed in a frame shape having a predetermined width, and a bottom surface 13 a that faces the upper end surface 1 a of the cylinder head 1 with a certain gap is formed in a flat shape. The vertical beam portions 16 and 17 are arranged around the three cylinders of the cylinder head 1 and are arranged substantially parallel to each other along the longitudinal direction of the cylinder head 1, and both the vertical beam portions. Four transverse beam portions 18 disposed along the width direction of the cylinder head 1 and one end wall portion 19 are provided between the cylinders 16 and 17.

  The inner vertical beam portion 16 is formed in a bent shape so as to avoid the three plug posts 20 integrally provided at the center position in the width direction of the cylinder head 1, while the outer vertical beam portion 17 is Further, it is disposed inside the rocker cover mounting surface 1b on the upper surface of the outer side of the cylinder head 1 so as to avoid the operating mechanism 7. A screw hole 1c is formed in the mounting surface 1.

  As shown in FIGS. 3 and 6, each of the transverse beam portions 18 is formed with a semicircular support groove 21 for bearing the lower portion of the drive shaft 3 at a substantially central position in the longitudinal direction of the upper surface.

  As shown in FIGS. 3 and 6, each main bracket 14 is formed in a substantially rectangular shape and has a flat lower surface disposed along the upper surface of each horizontal beam portion 18. A semicircular support groove 22 that is fitted from above and bearings the drive shaft 3 together with the support groove 21 is formed, and the control shaft 5 is provided at a substantially central position on a flat upper surface. A small-diameter semicircular bearing groove 23 for bearing the lower portion is formed.

  Each of the sub brackets 15 is formed in a substantially rectangular shape, and is fitted on the upper portion of the control shaft 5 at a substantially central position of the lower surface abutting on the upper surface of the main bracket 14 so as to cooperate with the bearing groove 23. Thus, a semicircular bearing groove 24 for bearing the control shaft 5 is formed.

  In addition, bolt insertion holes 26, 27, and 28 through which the bolts 25 that are part of the connecting means are inserted are continuously formed at both ends of each of the cross beam portions 18, the main bracket 14, and the sub bracket 15, respectively. ing.

  The end wall portion 19 has a substantially rectangular shape. As shown in FIGS. 1 and 2, a support hole 19a through which the end portion of the drive shaft 3 is inserted is formed in the lower portion and the upper portion is formed in the upper portion. A bearing hole 19b through which the end portion of the control shaft 5 is inserted is formed.

  The connecting means includes the bolt 25 having a relatively long shaft portion and a pair of female screw holes 29 and 29 which are formed in the upper end surface 1a of the cylinder head 1 and screwed to the tip end portion of each bolt 25. It consists of and.

  When the components of the drive shaft 3, the control shaft 5, and the operating mechanism 7 are temporarily fixed to the support 17, the main bracket 14, and the sub bracket 15 via bolts 25, 25, FIG. As shown in FIG. 4, nuts 30 and 30 are screwed onto the front ends of the shafts of the bolts 25 and 25 to be temporarily fixed.

  The operating mechanism 7 has a basic structure substantially the same as that of the conventional one, and a rocker arm 31 swingably supported on the control shaft 5 via a control cam 6 and upper ends of the intake valves 2 and 2. And a pair of oscillating cams 32 and 32 arranged so as to open and close the intake valves 2 and 2 in sliding contact with the outer peripheral surface of each roller 11a of each follower member 11. The eccentric cams 5, 5 and one end 31 a of the rocker arm 31 are linked by a link arm 33, while the other end 31 b of the rocker arm 31 and the swing cam 32 are linked by a link member 34.

  Each rocker arm 31 is bent in a substantially crank shape on a plane, and a cylindrical base portion at the center is rotatably supported by the control cam 6. Further, one end 31a projecting from the outer end of the base is rotatably connected to the link arm 33 via a pin 35, and the other end 31b is rotated to the link member 34 via a pin 36. It is connected freely.

  As shown in FIGS. 1, 6, and 7, the rocking cam 32 has a substantially U shape, and the drive shaft 3 is fitted into a substantially annular base end portion so as to be rotatably supported. A support hole is formed in a penetrating manner, and a lower end portion of the link member 34 is rotatably connected to a cam nose portion 32 a located on the other end portion 31 b side of the rocker arm 31 via a pin 37. Further, a base circle surface on the base end portion side and a cam surface extending in an arc shape from the base circle surface toward the end edge side of the cam nose portion 32a are formed on the lower surface of the swing cam 32. The surface is in rolling contact with a predetermined position on the outer peripheral surface of the roller 11 a of the follower member 11 in accordance with the swing position of the swing cam 32.

  The link arm 33 includes an annular base portion having a relatively large diameter and a projecting end projecting at a predetermined position on the outer peripheral surface of the base portion, and the outer periphery of the eccentric cam 5 is located at the center position of the base portion. A fitting hole that is rotatably fitted to the surface is formed, and the protruding end is rotatably connected to the other end 31 b of the rocker arm 31 via the pin 35.

  Further, the link member 34 is formed in a straight line having a predetermined length, and the other end portion 31b of the rocker arm 31 and the cam nose portion 32a of the swing cam 32 are provided via pins 36 and 37 at both ends of the circular shape. It is pivotally connected.

  The control shaft 5 is controlled to rotate within a predetermined rotation angle range by the electric motor, and the electric motor is driven by a control signal from a controller (not shown) that detects the operating state of the engine. It has become. The controller detects the current engine operating state based on detection signals from various sensors such as a crank angle sensor, an air flow meter, and a water temperature sensor, and outputs a control signal to the electromagnetic actuator.

Hereinafter, the operation of the present reference example will be described. Since the basic operation is the same as the conventional one, it will be briefly described. First, at the time of engine low speed and low load, the electric motor is driven to rotate in one direction by the control signal from the controller, and the control shaft 5 is rotated in the same direction. For this reason, the control cam 6 holds the shaft center P <b> 1 in the upper left rotation position from the shaft center P <b> 2 of the control shaft 5, and moves the entire rocker arm 31 upward with respect to the drive shaft 3. As a result, the cam nose portion 32a is forcibly slightly lifted through the link member 34 and the entire swing cam 32 is rotated rightward in FIG.

  Therefore, when the eccentric cam 5 rotates and pushes up the one end portion 31b of the rocker arm 31 via the link arm 33, the lift amount of the intake valve 2 from the swing cam 32 via the follower member 11 via the link member 34, However, the lift amount is relatively small.

  Therefore, in such a low-speed and low-load region, the valve lift amount is reduced, 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 at high engine speed and high load, the electric motor is driven to rotate in the opposite direction by the control signal from the controller, the control shaft 5 is also driven to rotate in the same direction, and the control cam 6 is rotated clockwise. The axis P1 (thick part) is moved downward. For this reason, the entire rocker arm 31 is moved in the direction of the drive shaft 3 (downward), and the other end 31b presses the cam nose 32a of the swing cam 32 downward via the link member 34. The entire moving cam 32 is rotated counterclockwise by a predetermined amount.

  Accordingly, the abutting position of the lower surface of the swing cam 32 with respect to the follower member 11 moves to the left position, so that when the eccentric cam 5 rotates and pushes the one end 31b of the rocker arm 31 through the link arm 33, the intake air The lift amount for the valves 2 and 2 is increased.

  Therefore, in such a high-speed and high-load region, the valve lift amount increases, 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.

As described above, in this reference example , the opening / closing timing and valve lift amount of each intake valve 2 can be made variable, and in addition to the control shaft 5, the rocker arm 31 and the swing cam 32 of the drive shaft 3 and the operating mechanism 7. Since all the components such as can be attached to the upper end portion of the cylinder head 1 in a state of being assembled together in advance to the support mechanism 9, the assembly work efficiency of the entire apparatus can be improved and the drive shaft 3 and the control can be controlled. High-precision centering between both shafts 5 is possible.

  That is, when assembling each component, first, each component such as the rocker arm 31, the swing cam 32, the link arm 33, and the link member 34 of the operating mechanism 7 is assembled to the drive shaft 3 and the control shaft 5. Thereafter, the end portions of the drive shaft 3 and the control shaft 5 are inserted and supported in the support holes 19a and the bearing holes 19b of the end wall portion 19 of the support mechanism 9, and the transverse beam portion 18 of the support body 13 and the main bracket 14 are A predetermined portion of the drive shaft 3 is disposed between the both support grooves 21 and 22, and a predetermined portion of the control shaft 5 is disposed between the bearing grooves 23 and 24 of the main bracket 14 and the sub bracket 15. 25 is inserted through the bolt insertion holes 28, 27, 28, respectively. Subsequently, as shown in FIG. 6, nuts 30 and 30 are screwed onto the front ends of the bolts 25 and 25, and each component is temporarily fixed to the support mechanism 9 in advance, and the whole is unitized as a unit. .

  In this state, the centering adjustment of the shaft centers of the drive shaft 3 and the control shaft 5 is performed.

  Thereafter, the unit body of each component is transported to the upper end portion of the cylinder head 1, where the nuts 30, 30 are removed from the bolts 25, 25, and the support body 13 is placed on the upper end surface 1 a of the cylinder head 1. The entire device can be mounted on the cylinder head 1 by placing the tip of each bolt 25 in the female screw hole 29 of the cylinder head 1 and tightening the bolt 25 head with a predetermined tool such as a spanner. Can be easily attached to the top.

  As described above, since all the components such as the drive shaft 3 and the like of the control shaft 5 of the apparatus are temporarily fixed to the support mechanism 9 in advance to form a unit body, the assembly work efficiency to the cylinder head 1 thereafter is greatly increased. improves.

  Moreover, since the centering operation of both the drive shaft 3 and the control shaft 5 is performed in the state where it is assembled to the support mechanism 9, it is compared with the case where it is performed with the cylinder head and the support mechanism assembled as in the prior art. Thus, the work accuracy is increased.

  As a result, since the operation of each operation mechanism 7 does not vary and substantially the same operation is obtained, the control of the valve lift amount of each intake valve 2 can be stabilized.

FIG. 7 shows a second reference example in which the width of the inner vertical beam portion 16 of the support 13 is made larger than that of the first embodiment, and the outer vertical beam portion 17 facing each link member 34 is shown. Are abolished while leaving the portion 17a on the end wall portion side. Other configurations are the same as those of the first reference example .

Accordingly, the same operational effects as those of the first reference example can be obtained, and space can be secured by eliminating the outer vertical beam portion. The replacement work of the member 34 becomes easy and the maintenance workability is improved.

  In addition, since the rigidity of the inner vertical beam portion 16 is high, it is possible to prevent the attachment rigidity of the support mechanism 9 to the cylinder head 1 from being lowered.

FIGS. 8 and 9 show a third reference example, which is applied to the three cylinders on the opposite side of the V-type six cylinder, and the inner vertical beam portion 16 of the support 13 is extended to the center of the cylinder head 1. In addition, a part of the inner vertical beam portion 16 is formed as an annular plug post 16a. That is, the front and rear portions 16b and 16c of the inner vertical beam portion 16 extend in an inclined manner toward the center of the upper end surface 1a of the cylinder head 1, and the portion of the cylinder head 1 in the portion between the tip portions of the both 16b and 16c. The part corresponding to the plug hole is formed as three plug posts 16a.

  Therefore, the presence of each plug post 16a increases the overall rigidity of the support 13 and, as shown in FIG. 9, the cylindrical plug insertion portion 40 formed on the rocker cover on the upper surface of each plug post 16a. Since the lower surface can be disposed in contact with the seal member 41, there is no need to form a plug post on the cylinder head 1, the structure of the cylinder head 1 is simplified, the manufacturing operation is facilitated, and the cylinder The versatility of the head 1 is increased.

Further, as in the fourth reference example shown in FIG. 10, the inner vertical beam portion 16 of the support 13 of the third reference example can be completely eliminated. In this case, the rigidity of the outer vertical beam portion 17 is increased by increasing the width.

11 and 12 show an embodiment of the present invention, which is applied to the support mechanism 9 of the first reference example . The end wall portion 19 has an electric motor 8 as an actuator and the rotational force of the electric motor 8. Is integrally provided with a transmission mechanism 42 for transmitting the control signal to the control shaft 5.

  That is, the transmission mechanism 42 is formed in a plate-like base member 44 fixed to the outer side surface of the end wall portion 19 by bolts 43, 43, and a case cover 45 coupled to the base member 44 by screws not shown. While being accommodated and held, the electric motor 8 is fixed to the outer side of the case cover 45 by screws 46.

  The transmission mechanism 42 includes a ball screw 49 that transmits the rotational force from the electric motor 8 by the bevel gears 47 and 48, a sliding portion 50 that slides in the axial direction as the ball screw 49 rotates, and the sliding mechanism. It is comprised from the rocking | swiveling member 51 which links the moving part 50 and the control shaft 5. As shown in FIG.

  Thus, since the electric motor 8 and the transmission mechanism 42 are integrally attached to the end wall portion 19 via the base member 44, the drive shaft 3, the control shaft 5, and the like are assembled to the support mechanism 9. At this time, if the electric motor 8 or the like is attached together, the unit property is further improved, and the work efficiency of assembling to the cylinder head 1 is further improved.

The present invention is not limited to the configurations of the respective reference examples and embodiments, and for example, the shape and structure of the support 13 can be freely changed according to the specifications of various engines. Of course, this apparatus can be applied to the exhaust side.

The principal part top view which shows the 1st reference example of this invention. The principal part side view of this reference example . FIG. 3 is a cross-sectional view taken along line AA in FIG. 2. The top view of the support mechanism with which the reference example is provided. The side view of the support mechanism. B arrow view of FIG. The top view which shows the 2nd reference example . The top view which shows the 3rd reference example . The CC sectional view taken on the line of FIG. The principal part top view which shows the 4th reference example . The principal part plane sectional view showing the embodiment of the present invention . D arrow line view of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Cylinder head 2 ... Intake valve 3 ... Drive shaft 4 ... Eccentric cam 5 ... Control shaft 6 ... Control cam 7 ... Actuation mechanism 8 ... Electric motor 9 ... Support mechanism 13 ... Support body 14 ... Main bracket 15 ... Sub bracket 16 ... Inner vertical beam portion 17 ... Outer vertical beam portion 18 ... Transverse beam portion 19 ... End wall portion 21, 22 ... Support groove 23, 24 ... Bearing groove 25 ... Bolt 20 ... Female screw hole 30 ... Nut

Claims (3)

A drive shaft that is rotationally driven by a crankshaft and provided with a rotating cam on the outer periphery;
A swing cam that swings by rotation of the rotary cam to open and close the engine valve;
A control shaft that is driven to change the lift position of the engine valve by changing the swing position of the swing cam;
An actuator comprising: an electric motor; and a transmission mechanism having a sliding portion that slides in the axial direction by the rotational force of the electric motor; and an actuator configured to link the sliding portion and the control shaft;
A pair of vertical beam portions facing each other across the cylinders, provided between the vertical beam portions, each horizontal beam portion arranged between the cylinders, and provided between the vertical beam portions, the transmission And an end wall portion through which a hole for transmitting power from the mechanism to the control shaft is formed, and the drive shaft and the control shaft are supported by a bracket fixed to each lateral beam portion with a bolt. A support mechanism;
With
Fixing the actuator integrally to the end wall,
The support mechanism is detachably attached to the cylinder head ,
The transmission mechanism is housed and held in a case cover, the electric motor is fixed to the case cover, and the case cover is fixed to the end wall portion. Variable valve device. The variable valve operating apparatus for an internal combustion engine according to claim 1,
The variable valve operating apparatus for an internal combustion engine, wherein the case cover is fixed to the end wall portion via a base member . A drive shaft that is rotationally driven by a crankshaft and provided with a rotating cam on the outer periphery;
A swing cam that swings by rotation of the rotary cam to open and close the engine valve;
A control shaft that is driven to change the lift position of the engine valve by changing the swing position of the swing cam;
An actuator comprising: an electric motor; and a transmission mechanism having a sliding portion that slides in the axial direction by the rotational force of the electric motor; and an actuator configured to link the sliding portion and the control shaft;
A support mechanism for detachably supporting the variable valve operating apparatus of the internal combustion engine with respect to the cylinder,
A pair of vertical beam portions facing each other across the cylinders, provided between the vertical beam portions, each horizontal beam portion arranged between the cylinders, and provided between the vertical beam portions, the transmission A hole through which an end of the control shaft for transmitting power from a mechanism to the control shaft is inserted, and an end wall portion to which the actuator is integrally fixed,
The drive shaft and the control shaft are supported by a bracket fixed to each lateral beam portion with a bolt,
The transmission mechanism is housed and held in a case cover, the electric motor is fixed to the case cover, and the case cover is fixed to the end wall portion. Support mechanism for variable valve device.

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