JP4205623B2 - Variable valve mechanism for internal combustion engine - Google Patents

Description

  The present invention relates to a variable valve mechanism that changes a valve lift amount, a working angle, and timing continuously or stepwise in accordance with the operating state of an internal combustion engine.

  As this type of variable valve mechanism, Patent Document 1 discloses a mechanism using a long and complicated link mechanism, but Patent Document 2 discloses a relatively simple configuration that does not use such a long and complex link mechanism. Things have been proposed. The latter variable valve mechanism is supported by a camshaft, a rotating cam provided on the camshaft, and a swingable shaft different from the camshaft, and has an input section (arm) and an output section (swinging cam). When the input unit is driven by the rotating cam, the intermediate drive mechanism that drives the valve at the output unit, and the intermediate phase difference variable that makes the relative phase difference between the input unit and the output unit of the intermediate drive mechanism variable Means.

The intermediate phase difference varying means includes an input part spline provided on the inner peripheral surface of the input part, an output part spline provided at an inner peripheral surface of the output part, and having an angle different from that of the input part spline, and an intermediate drive mechanism. A shaft body that can move in the axial direction, and has an input spline that meshes with the input spline and an output spline that meshes with the output spline on the outer peripheral surface of the shaft body. A slider gear that relatively swings the input portion and the output portion, and a displacement adjusting means that adjusts the displacement of the slider gear in the axial direction.
JP-A-11-324625 JP 2001-263015 A

  The intermediary phase difference varying means in the variable valve mechanism of Patent Document 2 requires an input portion spline on the inner peripheral surface of the input portion and an output portion spline on the inner peripheral surface of the output portion. There was a problem that gear processing of the peripheral surface was difficult.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a variable valve mechanism having a simple and inexpensive intermediate phase difference variable means that uses a hydraulic structure that is easy to process without using gears that are difficult to process.

The present invention is supported by a camshaft, a rotating cam provided on the camshaft, and a swingable shaft on a shaft different from the camshaft, and has an input portion and an output portion so that an input is provided by the rotating cam. and intermediary drive mechanism for driving the valves Te to the output section and the section is driven, the internal combustion engine having an intermediary phase difference varying means for varying the relative phase difference between the input portion and the output portion of the intermediary drive mechanism In the variable valve mechanism, the following {1} or {2} is characterized.
{1} the mediation phase difference varying means includes a support shaft provided in the bearing hole and an output section provided with a front entry force and an output to the input for relatively rotatably connected, the housing of the input unit to the hydraulic chamber for relative rotation with respect to the support shaft together with the bearing hole provided, rotatable relative to videos is by hydraulic pressure chamber and the low speed fast the hydraulic chamber in the hydraulic chamber with is provided in the output section The hydraulic chamber is partitioned into a hydraulic chamber for operation, and the hydraulic oil is supplied to the high-speed hydraulic chamber and the low-speed hydraulic chamber, and the high-speed hydraulic chamber and the low-speed hydraulic chamber. A hydraulic circuit for changing a hydraulic balance with the hydraulic chamber, and changing the hydraulic balance to change the relative phase difference, thereby making the lift amount of the valve continuously variable .
{2} The intermediary phase difference varying means is provided in a shaft provided in an input part that connects the input part and the output part so as to be relatively rotatable, a bearing hole provided in the output part, and a housing of the output part. A hydraulic chamber provided and rotated relative to the support shaft together with the bearing hole; and a hydraulic chamber provided in the input portion and accommodated in the hydraulic chamber so as to be rotatable relative to the hydraulic chamber. The hydraulic chamber is partitioned into a hydraulic chamber and is rotated relative to the bearing hole together with the support shaft, and hydraulic oil is supplied to the high-speed hydraulic chamber and the low-speed hydraulic chamber, and the high-speed hydraulic chamber and the low-speed hydraulic chamber are supplied. A hydraulic circuit that changes a hydraulic balance with the chamber, and changing the hydraulic balance to change the relative phase difference, thereby making the lift amount of the valve continuously variable.

In the above {2} aspect, if the support shaft is integrated with the input portion, the support span of the input portion becomes longer and stable, the rotation cam is prevented from being biased, and the working angle is less likely to vary. Therefore, it is preferable. In addition, the number of parts and cost can be reduced by integration.

  One set of the hydraulic chamber and the vane may be used, but it is preferable to provide two sets or three or more sets at an angular interval around the support shaft.

  The variable valve mechanism of the present invention can be applied to either the intake valve or the exhaust valve, but is preferably applied to both.

  ADVANTAGE OF THE INVENTION According to this invention, the variable valve mechanism provided with the intermediate | middle phase difference variable means of the simple hydraulic structure which does not use the gear which is difficult to process can be provided.

  The best mode of the variable valve mechanism is the variable valve mechanism of the internal combustion engine, wherein the intermediate phase difference varying means is provided relatively to the input unit and the output unit, and the input unit and the output unit are relatively A support shaft and a bearing hole that are rotatably connected, a hydraulic chamber that rotates relative to the support shaft together with the bearing hole, a hydraulic chamber that is housed in the hydraulic chamber so as to be relatively rotatable, and defines the hydraulic chamber, A vane that rotates relative to the bearing hole together with the support shaft; and a hydraulic circuit that supplies hydraulic oil to the partitioned hydraulic chamber.

  1 to 7 show the variable valve mechanism of the first embodiment. A plurality of cylinders (four cylinders are shown in FIG. 4) provided in the internal combustion engine are each formed with a combustion chamber. Each combustion chamber has two intake valves and two exhaust valves (not shown) in this example. The books are arranged one by one. The intake air amount control according to the operation of the accelerator pedal and the engine speed during idle speed control is performed by adjusting the lift amounts of the first intake valve 2a and the second intake valve 2b. The lift amount is adjusted by hydraulically driving a later-described intermediate drive mechanism 20 existing between the intake cam 6a (corresponding to the “rotary cam”) provided on the intake camshaft 6 and the rocker arm 4. Is done. Further, the valve timings of the intake valves 2a and 2b are adjusted according to the operating state of the engine by a known rotational phase difference varying means (not shown, for example, the actuator described in Patent Document 2 described above). The exhaust valve is opened and closed with a constant lift amount via a rocker arm by the rotation of an exhaust cam (not shown) provided on the exhaust camshaft. However, the lift amount can be made variable in the same manner as the intake valve. You can also.

  Now, the variable valve mechanism of the intake valves 2a and 2b will be described in detail. The variable valve mechanism includes an intermediate drive mechanism 20, a hydraulic circuit, and a rotation phase difference variable means (not shown).

  The intermediate drive mechanism 20 includes an input portion 22 provided in the center, a first swing cam 24 (corresponding to an “output portion”) provided on the left (right depending on the cylinder as described later), and a right (depending on the cylinder). Is provided with a second rocking cam 26 (corresponding to an “output portion”) provided on the left. The housing 22a of the input portion 22 and the housings 24a and 26a of the swing cams 24 and 26 are substantially disk-shaped with the same outer diameter.

  The housing 22a of the input portion 22 has a round hole-shaped bearing hole 22b penetrating the central portion in the axial direction, and two hydraulic chambers 22g extending in a fan shape continuously from, for example, two locations about 180 degrees apart of the bearing hole 22b. And are formed. Further, two arms 22c and 22d are formed to protrude in parallel from the outer peripheral surface. A shaft 22e is stretched between the arms 22c and 22d at the ends of the arms 22c and 22d. The shaft 22e is parallel to the axial direction of the housing 22a, and a roller 22f is rotatably attached thereto.

  The housing 24a of the first rocking cam 24 has a shaft mounting hole 24b penetrating the central portion in the axial direction, and a high speed penetrating through two locations 180 degrees apart from the shaft mounting hole 24b in the axial direction. An oil supply hole 24c is formed. A plurality of ears 24f projecting from the outer peripheral surface are formed with connecting holes 24g penetrating in the axial direction. A substantially triangular nose 24d protrudes from the outer peripheral surface. One side of the nose 24d forms a cam surface 24e that curves in a concave shape.

  The housing 26a of the second rocking cam 26 is internally provided with a shaft mounting hole 26b penetrating the central portion in the axial direction, and a low speed penetrating through two locations 180 degrees apart from the shaft mounting hole 26b in the axial direction. An oil supply hole 26c is formed. A plurality of ears 26f projecting from the outer peripheral surface are formed with connecting holes 26g penetrating in the axial direction. Further, a substantially triangular nose 26d protrudes from the outer peripheral surface. One side of the nose 26d forms a cam surface 26e that curves in a concave shape.

  The first rocking cam 24 and the second rocking cam 26 are disposed so that the end faces are coaxially contacted from both ends of the input portion 22 after the vane member 28 described below is attached, and the ear 24f. 26f, the spacer 30 is interposed, and the connecting screws 32 are connected to each other by being screwed into the female screw holes of the spacer 30 through the connecting holes 24g and 26g.

  The vane member 28 has a base shaft 28a that is longer than the left and right length of the input portion 22, the first swing cam 24, and the second swing cam 26, and a support shaft 28b that is concentrically formed at the center of the base shaft 28a. The support shaft 28b and the vane 28c provided radially from, for example, two positions 180 degrees away from the support shaft 28b. Both ends of the base shaft 28a are attached so as not to rotate by being press-fitted into the shaft mounting hole 24b of the first rocking cam 24 and the shaft mounting hole 26b of the second rocking cam 26. The support shaft 28b is fitted into the bearing hole 22b of the input portion 22 so as to be relatively rotatable. Each vane 28c is accommodated in each hydraulic chamber 22g of the input portion 22 so as to be relatively rotatable, and divides each hydraulic chamber 22g into a high-speed hydraulic chamber 22h and a low-speed hydraulic chamber 22i, and bearings together with the support shaft 28b. It rotates relative to the hole 22b. A high speed oil supply hole 24c is opened in the high speed hydraulic chamber 22h, and a low speed oil supply hole 26c is opened in the low speed hydraulic chamber 22i.

  As shown in FIG. 4, each intermediate drive mechanism 20 configured as described above is sandwiched between standing wall portions 36 and 38 formed on the cylinder head on the outer surfaces of the swing cams 24 and 26, and the swing cams The base shaft 28a protruding from the shafts 24 and 26 is rotatably fitted in the bearing holes of the standing wall portions 36 and 38, so that it can swing around the shaft but is prevented from moving in the axial direction. ing. In the four-cylinder example shown in FIG. 4, the second and fourth of the four intermediary drive mechanisms 20 from the left are the first rocking cam 24 on the left and the second rocking cam 26 on the right. In the first and third ones from the left, the first swing cam 24 is on the right and the second swing cam 26 is on the left.

  Of the five standing wall portions, the second and fourth standing wall portions 36 from the left are formed with oil passages 36a communicating with the high-speed oil supply holes 24c of the first swing cam 24, and the first and third from the left. An oil passage 38 a that communicates with the low-speed oil supply hole 26 c of the second swing cam 26 is formed in the fifth and fifth standing wall portions 38. Each oil passage 36a, 38a is connected to a hydraulic pump (not shown) via a valve (not shown). These hydraulic pumps, valves, oil passages 36a and 38a, oil supply holes 24c and 26c, etc. supply hydraulic oil to the high speed hydraulic chamber 22h and the low speed hydraulic chamber 22i and change the hydraulic balance between the hydraulic chambers 22h and 22i. A hydraulic circuit is configured.

  The roller 22f provided in the input part 22 of the mediation drive mechanism 20 is in contact with the intake cam 6a as shown in FIG. Therefore, the input portion 22 of each intermediary drive mechanism 20 swings around the axis of the base shaft 28a according to the profile of the cam surface of the intake cam 6a. The arms 22c and 22d that support the roller 22f are provided with compression springs (not shown) that urge the roller 22f in the direction of the intake cam 6a. For this reason, the roller 22f is always in contact with the cam surface of the intake cam 6a.

  On the other hand, the swing cams 24 and 26 are in contact with the respective rollers 4 a provided at the center of the two rocker arms 4 at the base circle portions. The rocker arm 4 is supported by the adjuster 4b at the base end portion 4c so as to be swingable with respect to the cylinder head, and is in contact with the stem ends 2c of the intake valves 2a and 2b at the tip end portion 4d.

  As described above, the hydraulic fluid is supplied to the high-speed hydraulic chamber 22h and the low-speed hydraulic chamber 22i by the hydraulic circuit, and the hydraulic pressure balance between the hydraulic chambers 22h and 22i is changed, thereby changing the vibration to the input portion 22 (bearing hole 22b). By changing the relative rotation angle of the moving cams 24 and 26 (vanes 28c), the phase difference between the roller 22f of the input unit 22 and the noses 24d and 26d of the swing cams 24 and 26 can be adjusted, so that the intake valves 2a and 2b. The lift amount can be made continuously variable.

The variable valve mechanism of the present embodiment operates as follows during operation of the internal combustion engine.
First, FIG. 5 shows an operating condition that requires the maximum lift amount. Although the second rocking cam 26 shows a mechanism for driving the first intake valve 2a in the figure, the same applies to the mechanism for the first rocking cam 24 to drive the second intake valve 2b. At this time, the hydraulic pressure in the high-speed hydraulic chamber 22h is made higher than the hydraulic pressure in the low-speed hydraulic chamber 22i by the hydraulic circuit, and the swing cams 24 and 26 rotate clockwise in FIG. As a result, the phase difference between the roller 22f of the input portion 22 and the noses 24d and 26d of the swing cams 24 and 26 increases, so that the base circle portion of the intake cam 6a contacts the roller 22f as shown in FIG. In this case, the noses 24d and 26d of the swing cams 24 and 26 are not in contact with the roller 4a of the rocker arm 4, and the base circle portions adjacent to the noses 24d and 26d are in contact. When the nose 6b of the intake cam 6a depresses the roller 22f as shown in FIG. 5B, the swing is transmitted from the input portion 22 to the swing cams 24 and 26 via the vane 28c in the intermediate drive mechanism 20. Thus, the swing cams 24 and 26 swing so as to push down the noses 24d and 26d. As a result, the curved cam surfaces 24e and 26e provided on the noses 24d and 26d immediately come into contact with the roller 4a of the rocker arm 4, and the roller 4a is pushed down using the entire range of the cam surfaces 24e and 26e. As a result, the rocker arm 4 swings around the base end 4c side, and the distal end 4d of the rocker arm 4 largely pushes down the stem end 2c. Thus, the intake valves 2a and 2b open the intake port (not shown) at the maximum lift amount Lmax.

  Next, FIG. 6 shows an operating condition in which the lift amount should be reduced. At this time, the hydraulic pressure in the low-speed hydraulic chamber 22i is brought close to or higher than the hydraulic pressure in the high-speed hydraulic chamber 22h in the hydraulic circuit, and the swing cams 24 and 26 rotate counterclockwise in FIG. . As a result, the phase difference between the roller 22f of the input portion 22 and the noses 24d and 26d of the swing cams 24 and 26 is reduced, so that the base circle portion of the intake cam 6a contacts the roller 22f as shown in FIG. In this case, the noses 24d and 26d of the swing cams 24 and 26 are not in contact with the roller 4a of the rocker arm 4, and are slightly separated from the noses 24d and 26d as compared with the case of FIG. The base circle is in contact. Therefore, even if the nose 6b of the intake cam 6a starts to push down the roller 22f, the roller 4a of the rocker arm 4 does not contact the curved cam surfaces 24e and 26e provided on the noses 24d and 26d for a while, and does not contact the base circle portion. Continue touching. Thereafter, as shown in FIG. 6B, the curved cam surfaces 24e and 26e come into contact with the roller 4a and push down the roller 4a, so that the rocker arm 4 swings about the base end 4c. The swing angle of the arm 4 becomes small, and the amount by which the stem end 2c is pushed down, that is, the lift amount L becomes small. Thus, the intake valves 2a and 2b open the intake port with a lift amount smaller than the maximum amount.

Next, FIG. 7 shows an operating condition in which the lift amount should be zero. At this time, the hydraulic pressure in the low-speed hydraulic chamber 22i is made higher than the hydraulic pressure in the high-speed hydraulic chamber 22h by the hydraulic circuit, and the swing cams 24 and 26 rotate further counterclockwise in the drawing together with the vane 28c. As a result, the phase difference between the roller 22f of the input portion 22 and the noses 24d and 26d of the swing cams 24 and 26 is minimized, so that the base circle portion of the intake cam 6a contacts the roller 22f in the mediation drive mechanism 20. In this case, the noses 24d and 26d of the swing cams 24 and 26 are not in contact with the roller 4a of the rocker arm 4, and a base circle portion that is far away from the noses 24d and 26d is in contact. Therefore, even if the nose 6b of the intake cam 6a depresses the roller 22f, the roller 4a of the rocker arm 4 contacts the base circle portion without contacting the curved cam surfaces 24e and 26e provided on the noses 24d and 26d. Continue state. As a result, the rocker arm 4 does not swing around the base end portion 4 c, and the amount by which the stem end 2 c is pushed down by the distal end portion 4 d of the rocker arm 4, that is, the lift amount L becomes zero.

  Since the adjustment of the hydraulic pressure balance by the above hydraulic circuit is continuously performed, the lift amount of the intake valves 2a and 2b can be continuously adjusted. That is, the intermediate phase difference varying means is configured by the bearing hole 22b, the hydraulic chambers 22h and 22i, the support shaft 28b, the vane 28c, and the hydraulic circuit. Since this intermediate phase difference varying means does not use gears that are difficult to process and is easy to process, the cost can be reduced.

  Next, FIGS. 8 to 11 show the variable valve mechanism of the second embodiment. The second embodiment is different from the first embodiment in the points described below, and the description of the first embodiment is used for the other common parts with the first embodiment.

  The intermediate drive mechanism 20 in the second embodiment also includes an input unit 22, a first rocking cam 24, and a second rocking cam 26, but each shape is different from that in the first embodiment.

  The input portion 22 is radially formed from a support shaft 22p longer than the left and right length of the input portion 22, the first rocking cam 24, and the second rocking cam 26, and two portions of the support shaft 22p, for example, about 90 degrees apart. And a vane 22q provided in the vehicle. From one end surface of the support shaft 22p, a high-speed oil supply hole 22r is formed which opens to the outer peripheral surface of the support shaft 22p immediately below one surface of each vane 22q. A low speed oil supply hole 22s is formed in the outer peripheral surface of the shaft 22p. Further, the two arms 22c and 22d protrude in parallel from the support shaft 22p, and the roller 22f is attached to the arms 22c and 22d by the shaft 22e as in the first embodiment.

  The housing 24a of the first swing cam 24 is formed with a bearing hole 24p that penetrates the central portion in the axial direction and three connection holes 24q that penetrate the vicinity of the periphery in the axial direction. The nose 24d and the cam surface 24e are the same as those in the first embodiment.

  The housing 26a of the second rocking cam 26 has a columnar shape with a part cut away longer than the housing 24a of the first rocking cam 24, and a bearing hole 26p penetrating the center portion in the axial direction, and the vicinity of the periphery in the axial direction. Are formed with three connecting holes 26q. The nose 26d and the cam surface 26e are the same as those in the first embodiment. The housing 26a is formed with notches 26r for allowing the arms 22c and 22d of the input portion 22 to escape, and two hydraulic chambers 26s continuously extending in a fan shape from two locations, for example, about 90 degrees apart from the bearing hole 26p. Is formed.

  The first rocking cam 24 and the second rocking cam 26 are arranged from both ends of the input portion 22 so that both ends of the support shaft 22p of the input portion 22 are fitted into the bearing holes 24p and 26p so as to be relatively rotatable. At the same time, the connecting screws 32 are screwed into the connecting holes 24q and 26q to be connected to each other. Each vane 22q is accommodated in each hydraulic chamber 26s of the second swing cam 26 so as to be relatively rotatable, and divides each hydraulic chamber 26s into a high-speed hydraulic chamber 26t and a low-speed hydraulic chamber 26u. Together with 22p, it rotates relative to the bearing holes 24p, 26p. A high speed oil supply hole 22r opens in the high speed hydraulic chamber 26t, and a low speed oil supply hole 22s opens in the low speed hydraulic chamber 26u.

  As shown in FIG. 11, each of the intermediate drive mechanisms 20 configured as described above is sandwiched between standing wall portions 36 and 38 formed on the cylinder head on the outer surfaces of the swing cams 24 and 26, and the swing cams The pivot shafts 22p projecting from the shafts 24 and 26 are rotatably fitted in the bearing holes of the standing wall portions 36 and 38, so that they can swing around the shafts but are prevented from moving in the axial direction. Has been. In the example of the four cylinders shown in FIG. 11, the second and fourth of the four intermediary drive mechanisms 20 from the left are the first rocking cam 24 on the left and the second rocking cam 26 on the right. In the first and third ones from the left, the first swing cam 24 is on the right and the second swing cam 26 is on the left.

  Of the five standing wall portions, the second and fourth standing wall portions 36 from the left are formed with oil passages 36a communicating with the high-speed oil supply holes 22r of the input portion 22, and the first, third and fifth from the left. An oil passage 38 a communicating with the low speed oil supply hole 22 s of the input portion 22 is formed in the second standing wall portion 38. Each oil passage 36a, 38a is connected to a hydraulic pump (not shown) via a valve (not shown). These hydraulic pumps, valves, oil passages 36a and 38a, oil supply holes 22r and 22s, etc. supply hydraulic oil to the high-speed hydraulic chamber 26t and the low-speed hydraulic chamber 26u, and change the hydraulic balance between the hydraulic chambers 26t and 26u. A hydraulic circuit is configured. By changing the hydraulic balance, the relative rotation angle of the swing cams 24 and 26 (bearing holes 24p and 26p) with respect to the input portion 22 (vane 22q) is changed, and the roller 22f of the input portion 22 and the swing cams 24 and 26 are changed. The phase difference from the noses 24d and 26d can be adjusted, so that the lift amounts of the intake valves 2a and 2b can be made continuously variable.

  Therefore, the operation and effect similar to those of the first embodiment can be basically obtained by the second embodiment. Further, since the support shaft 22p is integrated with the input portion 22, the support span of the input portion 22 is lengthened and stabilized, and the intake cam 6a is prevented from being biased against the roller 22f. Since it is hard to come out, it is preferable. In addition, the number of parts and cost can be reduced by integration.

  In addition, this invention is not limited to the structure of the said Example, It can also change and embody in the range which does not deviate from the meaning of invention.

It is a perspective view which shows the variable valve mechanism based on Example 1 of this invention. It is a perspective view which shows the state which decomposed | disassembled the principal part of the mechanism. It is the side view which removed the 1st rocking cam of the mechanism and looked at the mechanism. It is sectional drawing which shows the same mechanism for 4 cylinders pinched | interposed into the standing wall part of a cylinder head. The principal part of the mechanism when the maximum lift amount is required is shown, (a) is a side view at the time of a base circle, and (b) is a side view at the time of a nose. The principal part of the mechanism when reducing the lift amount is shown, (a) is a side view at the base circle, (b) is a side view at the nose. The principal part of the mechanism when the lift amount is set to 0 is shown, (a) is a side view at the time of a base circle, and (b) is a side view at the time of a nose. It is a perspective view which shows the variable valve mechanism based on Example 2 of this invention. It is a perspective view which shows the state which decomposed | disassembled the principal part of the mechanism. It is the side view which removed the 1st rocking cam of the mechanism and looked at the mechanism. It is sectional drawing which shows the same mechanism for 4 cylinders pinched | interposed into the standing wall part of a cylinder head.

Explanation of symbols

2a 1st intake valve 2b 2nd intake valve 4 rocker arm 4a roller 6 intake camshaft 6a intake cam 20 intermediate drive mechanism 22 input part 22b bearing hole 22h high speed hydraulic chamber 22i low speed hydraulic chamber 22p support shaft 22q vane 22r high speed Oil supply hole 22s Low speed oil supply hole 24 First rocking cam 24c High speed oil supply hole 24p Bearing hole 26 Second rocking cam 26c Low speed oil supply hole 26p Bearing hole 26t High speed hydraulic chamber 26u Low speed hydraulic chamber 28 Vane member 28b Support Shaft 28c Vane 36a Oil passage 38a Oil passage

Claims (3)

A camshaft (6), a rotating cam (6a) provided on the camshaft, and a camshaft supported by a shaft different from the camshaft are supported, and an input portion (22) and an output portion (24, 26). Doo valves (2a, 2b) Te to the output portion and the input portion is driven by the rotary cam by having an intermediary drive mechanism for driving (20), between the input portion and the output portion of the intermediary drive mechanism In a variable valve mechanism for an internal combustion engine provided with an intermediate phase difference variable means for making the relative phase difference variable,
The mediation phase difference varying means, the entering-force unit and the bearing hole provided in the input unit of the output unit for connecting relatively pivotably (22b) and the support shaft provided on the output section (28b), said input A hydraulic chamber (22g) which is provided in the housing (22a) of the portion and rotates relative to the support shaft together with the bearing hole, and is provided in the output portion and accommodated in the hydraulic chamber so as to be relatively rotatable. The hydraulic chamber is divided into a high-speed hydraulic chamber (22h) and a low-speed hydraulic chamber (22i), a vane (28c) that rotates relative to the bearing hole together with the support shaft, the high-speed hydraulic chamber, and the low-speed hydraulic chamber and a hydraulic circuit for changing the pressure balance between the hydraulic chamber and the low-speed hydraulic chamber for the high speed with which supplies hydraulic oil to the hydraulic chamber,
A variable valve operating mechanism for an internal combustion engine , wherein the relative phase difference is changed by changing the hydraulic pressure balance so that the lift amount of the valve is continuously variable . A camshaft (6), a rotating cam (6a) provided on the camshaft, and a camshaft supported by a shaft different from the camshaft are supported, and an input portion (22) and an output portion (24, 26). Doo valves (2a, 2b) Te to the output portion and the input portion is driven by the rotary cam by having an intermediary drive mechanism for driving (20), between the input portion and the output portion of the intermediary drive mechanism In a variable valve mechanism for an internal combustion engine provided with an intermediate phase difference variable means for making the relative phase difference variable,
The mediation phase difference varying means, the entering-force unit and the support shaft provided in the input unit of the output unit for connecting relatively pivotably (22p) and a bearing hole provided in an output portion (24p, 26p), A hydraulic chamber (26s) provided in the output portion housing (26a) and rotated relative to the support shaft together with the bearing hole, and provided in the input portion and accommodated in the hydraulic chamber so as to be relatively rotatable. The hydraulic chamber is divided into a high-speed hydraulic chamber (26t) and a low-speed hydraulic chamber (26u), the vane (22q) rotating relative to the bearing hole together with the support shaft, the high-speed hydraulic chamber, and a hydraulic circuit for changing the pressure balance between the hydraulic chamber and the low-speed hydraulic chamber for the high speed with which supplies hydraulic fluid to the low-speed hydraulic chamber,
A variable valve operating mechanism for an internal combustion engine , wherein the relative phase difference is changed by changing the hydraulic pressure balance so that the lift amount of the valve is continuously variable . The variable valve mechanism for an internal combustion engine according to claim 2 , wherein the support shaft (22p) is integrated with the input portion (22).

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