JP2000104509A - Valve system for engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve a weight balance of an actuator so as to reduce noise and vibration by arranging a vane type variable valve timing actuator in one end of a camshaft and arranging a recess part in the body part matching the vane blade arranging position. SOLUTION: In a variable valve timing actuator 20A regulating opening/ closing timing for an intake/exhaust valve, first-fourth blades 30 (30A-1, 30A-2, 30A-3, 30A-4) of a cross-shaped vane 24A are individually housed in first-fourth recess parts 28A-1, 28A-2, 28A-3, 28A-4 formed inside a case 22A. When an oil pressure is applied to either of chambers positioned on the left and right sides of each blade 30, actuating torque is generated. In this case, for improving a weight balance of the actuator 20A to a rotation center C position of a camshaft, at least one recess part 68 is arranged in a body part 26 matching the arrangement position for the only one blade 30 in the vane 24A, so that generation of vibration can be suppressed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a valve operating device for an engine, and more particularly to a concave portion provided in a body to improve the balance of the entire variable valve timing actuator, and to achieve balance after the variable valve timing actuator is assembled. It is possible to reduce the number of processes and costs, and to reduce the vibration and noise from the camshaft and to improve the durability and reliability of the cam journal part. The present invention relates to a valve train.

[0002]

2. Description of the Related Art An engine is provided with a valve train for transmitting a driving force of a crankshaft to a camshaft to open and close a valve for intake and exhaust.

[0003] In addition, some valve trains are provided with a cam timing for opening and closing a valve for intake and exhaust, that is, a variable valve timing (hereinafter referred to as "VVT") actuator for shifting the phase between a crankshaft and a camshaft. is there.

The VVT actuator includes a helical gear type, a helical spline type, and a vane type.

[0005] An example of the valve train of the engine is disclosed in Japanese Patent Application Laid-Open No. 10-141023. A valve operating device for an internal combustion engine disclosed in this publication is provided so as to be rotatable relative to a first camshaft and has a recess therein, and is connected to the first camshaft to be rotatable within the housing. A vane having a pressure receiving portion defining a concave portion of the housing and forming a liquid chamber on at least one side thereof, and a second gear connected to the housing and provided on the second camshaft. A first gear meshed and connected, and a valve driven to be opened and closed by the first and second camshafts in response to a change in the relative rotational phase of the housing and the vane based on hydraulic control of the liquid chamber to be formed. A thrust bearing for supporting the thrust of the first gear in the axial direction is provided on the first camshaft. Thereby suppressing the occurrence of generation or uneven wear of the noise caused by meshing poor gear.

[0006] Also, there is one disclosed in JP-A-10-148109. A valve operating device for an internal combustion engine disclosed in this publication is provided so as to be rotatable relative to a first camshaft and has a recess therein, and is connected to the first camshaft to be rotatable within the housing. A vane having a pressure receiving portion defining a concave portion of the housing and forming a liquid chamber on at least one side thereof, and a second gear connected to the housing and provided on the second camshaft. A first gear meshed and connected, and a valve driven to be opened and closed by the first and second camshafts in response to a change in the relative rotational phase of the housing and the vane based on hydraulic control of the liquid chamber to be formed. In the valve gear of an internal combustion engine for changing at least one of the valve timings, an elastic body is interposed between the housing and the first gear, and the elastic body is generated due to poor meshing between the gears. Thereby suppressing the transmission of the noise of the housing or the cam shaft.

[0007]

As shown in FIG. 17, in a conventional valve train of an engine, an engine 2A includes a cylinder block 4A, a cylinder head 6A mounted on an upper surface of the cylinder block 4A, and It has a cylinder head cover 8A mounted on the upper surface of the cylinder head 6A, and an oil pan 10A mounted below the cylinder block 6A.

A crankshaft 12A is pivotally provided on the lower surface of the cylinder block 4A, and two intake first camshafts 14 are provided on the upper surface of the cylinder head 6A.
A and the second exhaust camshaft 16A are pivotally provided.

Then, a crank timing sprocket 18A is mounted on one end of the crankshaft 12A, that is, on the surface side which is one side of the engine 2A, and a VVT actuator 20A is provided on one end of the first camshaft 14A.

At this time, as shown in FIGS. 20 and 21, the vane type VVT actuator 20A includes a case 22A, a vane 24A, and a body 26A. 4 recesses 28
A-1, 28A-2, 28A-3, 28A-4 are formed, and the first to fourth recesses 28A-1, 28A-2,
The first to fourth blades 30A- of the vane 24A formed in a cross shape in 28A-3 and 28A-4 (see FIG. 24).
1, 30A-2, 30A-3, and 30A-4 are respectively positioned, and the first to fourth recesses 2 are rotated by the rotation of the vane 24A.
8A-1, 28A-2, 28A-3, 28A-4 and the first to fourth blades 30A-1, 30A-2, 30A-3, 3
At 0A-4, the first to fourth retard chambers 32A-1, 32A-
2, 32A-3, 32A-4 or the first to fourth advance chambers 34A-1, 34A-2, 34A-3, 34A-4.

In other words, the vane-type VVT actuator 20A has a plurality of blades arranged inside the VVT actuator 20A, and applies hydraulic pressure to one of the rooms located on the left and right sides of the blade to generate operating torque. Things.

An outwardly protruding sprocket portion 36A is formed at the engine-side end of the body 26A of the VVT actuator 20A, and a sprocket portion 36A and a first sprocket portion mounted on one end of the second camshaft 16A are provided. A two-cam sprocket 38A and a timing chain 40A for crank timing sprocket 18A are wound and provided.

Here, the flow of oil in the engine 2A will be described. The oil in the oil pan 10A is sucked through an oil strainer 44A by an oil pump 42A disposed at one end of a crankshaft 12A, and the engine It is supplied to each part.

At this time, a part of the oil pressure from the oil pump 42A is supplied to an oil control valve (also referred to as "OCV") 48A via an oil pipe 46A.

This oil control valve 48A is
The engine is controlled by control means (not shown), and a retard passage 50A or an advance passage provided in the cylinder head 6A in order to secure an optimum cam timing according to an engine operating condition by a control signal from the control means. 52
Distribute hydraulic pressure to A.

The hydraulic pressure distributed to the retard passage 50A or the advance passage 52A passes through the first camshaft 14A and is supplied to the VVT actuator 20A, which converts the hydraulic pressure into driving torque to convert the first camshaft 14A. And VVT
The phase of the actuator 20A is shifted from that of a sprocket portion 36A formed on the body 26A.

Reference numeral 54A is a mounting bolt for mounting the VVT actuator 20A to the first camshaft 14A, and 56A is a mounting bolt for mounting the case 22A and the body 26A of the VVT actuator 20A.

In the vane type VVT actuator 20A, the blade 3 is moved between the most retarded position and the most advanced position.
0A contacts case 22A and stops. However, the plurality of first to fourth blades 30A-1, 30A-
Since it is very difficult to simultaneously bring the 2, 30A-3 and 30A-4 into contact with the case 22A in terms of processing accuracy, usually, as shown in FIG. 22 or FIG. To contact only 30A-1,
The first blade 30A-1 functions as a stopper.

That is, as shown in FIGS. 22 and 23, the second to fourth blades other than the first blade 30A-1 of the vane 24A.
In the blades 30A-2, 30A-3, and 30A-4,
A gap S appears in each case 22A.

At this time, as shown in FIG. 24, the operating torque of the VVT actuator 20A is concentrated and received only on the first blade 30A-1 of the vane 24A.
The blade 30A-1 is replaced with the other second to fourth blades 30A-2, 30
It is formed thicker and larger than A-3 and 30A-4.

That is, the other second to fourth blades 30A-2,
The weight of the first blade 30A-1 functioning as a stopper is larger than 30A-3 and 30A-4.

As a result, in the vane 24A alone,
As shown in FIG. 24, the position of the center of gravity G1A is shifted from the position of the rotation center CA of the camshaft to the position of the first blade 30A-1 having a large weight.
The VVT actuator 20A, which is a rotating body, is unbalanced in structure.

If the weight imbalance is large, vibrations and noises from the camshaft become large, which is disadvantageous in practical use, and requires the strength of the camshaft to be increased. However, there is a disadvantage that it is economically disadvantageous.

[0024]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a vane type variable valve timing actuator at one end of a camshaft. A case having a plurality of chambers inside,
The vane is housed in the case and rotates integrally with the camshaft, and is formed by a body having a timing sprocket portion, and serves as a stopper portion when a plurality of blades corresponding to the chamber are formed in the vane. In the valve train of an engine provided with a function and a large single blade, an arrangement of the single blade of the vane is preferable in order to achieve a good weight balance of the variable valve timing actuator with respect to the rotational center position of the camshaft. At least one concave portion is provided in the body portion corresponding to the installation position.

[0025]

BEST MODE FOR CARRYING OUT THE INVENTION
The concave portion provided in the body improves the balance of the variable valve timing actuator as a whole, eliminating the need for balancing after assembling the variable valve timing actuator, reducing the number of processes and reducing costs. Vibration from camshaft
It has reduced noise and improved the durability and reliability of the cam journal.

[0026]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the drawings.

FIGS. 1 to 3 show a first embodiment of the present invention.

In the disclosure of the above-described conventional configuration, the reference numeral is appended with “A”. However, in the following embodiments, when describing the components having the same function, “A” will be used.
Is explained.

In FIGS. 1 and 2, reference numeral 26 denotes a body of a vane type VVT actuator (not shown).

In the body 26, a main body 62 is formed in a thick cylindrical shape, and a timing sprocket portion 36 protruding outwardly is formed at an end of the main body 62 on the engine side. A through hole 64 through which a first camshaft (not shown) is inserted is formed at the center.

Further, in the main body portion 62 of the body 26, a plurality of, for example, four
A mounting bolt (not shown) for mounting a case (not shown) of the VVT actuator and the body 26 is engaged with the mounting hole 66.

Usually, the body 26 is formed in a structure having no imbalance. However, the case (not shown), the vane (not shown) and the body
When the actuator was assembled, the vanes were unbalanced by the first blade (not shown) functioning as a stopper, and the entire VVT actuator was unbalanced.

Therefore, in order to improve the weight balance of the VVT actuator with respect to the rotation center C position of the camshaft, at least one concave portion 68 is provided in the body 26 corresponding to the position where the only blade of the vane is disposed.
Is provided.

More specifically, when the only blade of the vane is located at the most retarded position, the concave portion 68 is provided in the main body 6 as shown in FIGS. 1 to 3 so as to correspond to the single blade.
One is formed in the vicinity of the outer peripheral portion and at the inner portion of the timing sprocket portion 36 formed to protrude at the end on the engine side.

More specifically, when the position of the center of gravity of the vane is shifted upward (see FIG. 24), as shown in FIG. Thus, the substantially square concave portion 68 is formed, and the center of gravity G of the body 26 is shifted downward.

In this case, each of the vane and the body 26 has an imbalance in a single body, but after the assembly, each of the imbalances is canceled, and the balance of the entire VVT actuator is improved.

In some cases, the VVT actuator has a built-in lock pin mechanism that causes an unbalance. However, the unbalanced state of components other than the body 26 such as the lock pin mechanism is changed to the unbalanced state of the body 26. It is also possible to offset.

Next, the operation will be described.

At the time of assembling the VVT actuator, the case and the body 2 are arranged while the vanes are arranged in the case.
6 is assembled with an assembling bolt (not shown), and the vane is fixed to one end of the first camshaft.

At this time, each of the vane having the heavy first blade and the body 26 having the concave portion 68 is
Although a single unit has an imbalance, the weight balance is offset after assembly and the imbalance is reduced, thereby improving the balance of the entire VVT actuator.

Thus, the concave portion 68 provided in the body 26 eliminates the need for balancing after assembling the VVT actuator, which can reduce the number of steps and cost, and is economically advantageous. is there.

Further, since the concave portion 68 provided in the body 26 can improve the balance of the entire VVT actuator, vibration and noise from the cam shaft can be reduced, and the durability and reliability of the cam journal portion can be reduced. Can be improved, the strength of the camshaft can be reduced, and the weight can be reduced.

Further, since it can be dealt with only by forming the concave portion 68 in the body 26, the configuration is simple, the manufacturing is easy, the cost can be kept low, and it is economically advantageous.

Further, when the only blade of the vane is located at the most retarded position, the concave portion 68 protrudes to the vicinity of the outer peripheral portion of the main body portion 62 and to the engine side end so as to correspond to the only blade. By forming one piece on the inner side of the formed timing sprocket portion 36, the weight balance on the retard side is improved, which is practically advantageous.

FIGS. 4 to 6 show a second embodiment of the present invention. In the second embodiment, portions that perform the same functions as those in the first embodiment will be described with the same reference numerals.

The feature of the second embodiment is that, in order to improve the weight balance on the retard side, when the sole vane of the vane is located at the most advanced position, the vane is made to correspond to the sole vane. That is, a concave portion 72 is formed in the body 26.

That is, when the only vane of the vane is located at the most advanced position, the position of the center of gravity of the vane is shifted in the upper right direction. As shown in FIG. 4, the substantially square concave portion 72 is formed by casting or machining.
The center of gravity G of No. 6 is shifted downward and to the right. (Note that in FIG. 4, since the body 26 is disclosed from the back side, the direction of displacement of the position of the center of gravity of the vane and the direction of displacement of the position of the center of gravity G of the body 26 are the same in the left-right direction. ing.)

The recess 7 provided in the body 26
2, there is no need to balance after assembling the VVT actuator, as in the first embodiment described above.
The number of steps can be reduced, the cost can be reduced, and it is economically advantageous.

Further, since the balance of the entire VVT actuator can be improved by the concave portion 72 provided in the body 26, vibration and noise from the camshaft can be reduced as in the first embodiment. In addition, the durability and reliability of the cam journal portion can be improved, the strength of the cam shaft can be reduced, and the weight can be reduced.

Further, since it can be dealt with only by forming the concave portion 72 in the body 26, as in the first embodiment, the structure is simple, the manufacture is easy, and the cost can be kept low. It is economically advantageous.

Further, when the only blade of the vane is located at the most advanced position, the concave portion 72 is formed in the vicinity of the outer peripheral portion of the main body and at the end on the engine side so as to correspond to the single blade. By forming one on the inner side of the timing sprocket portion, the weight balance on the advance side is improved, which is practically advantageous.

FIGS. 7 to 9 show a third embodiment of the present invention.

The feature of the third embodiment is that, in order to improve the weight balance from the advance side to the retard side, only the vane of the vane is positioned at the intermediate position between the most advanced position and the most retarded position. Is that a concave portion 82 is formed in the body 26 so as to correspond to the only blade.

That is, when the only blade of the vane is located at an intermediate position between the most advanced position and the most retarded position, the position of the center of gravity of the vane is slightly displaced in the upper right direction. As shown in FIG. 7, the recesses 82 are formed in the body 26 in the
To shift the center of gravity G of the body 26 slightly downward and to the right.

At this time, as shown in FIG. 7, the concave portion 82 is formed in the shape of a long hole reaching from the most advanced position to the most retarded position, and at the same time, as shown in FIGS. Are formed to be approximately half of those of the first and second embodiments.

The recess 8 provided in the body 26
2 as in the first and second embodiments.
There is no need to balance after assembling the VT actuator, the number of steps can be reduced, and the cost can be reduced, which is economically advantageous.

Further, the balance of the entire VVT actuator can be improved by the concave portion 82 provided in the body 26, so that the vibration and noise from the camshaft can be reduced as in the first and second embodiments. In addition, the durability and reliability of the cam journal portion can be improved, the strength of the camshaft can be reduced, and the weight can be reduced.

Further, since it can be dealt with only by forming the concave portion 82 in the body 26, similarly to the first and second embodiments, the structure is simple, the manufacturing is easy, and the cost is low. It can be maintained and is economically advantageous.

Further, when the only blade of the vane is located at an intermediate position between the most advanced position and the most retarded position, the concave portion 82 is formed on the outer peripheral portion of the main body so as to correspond to the only blade. By forming one piece in the vicinity of and inside the timing sprocket portion protruding from the engine side end, the weight balance from the advance side to the retard side is improved, which is practically advantageous.

The present invention is not limited to the above-described first to third embodiments, and various modifications can be made.

For example, in the first to third embodiments of the present invention, one and various concave portions are disclosed on the advance side and / or the retard side, but two or more concave portions may be formed. And the following concave portions are also possible.

That is, when the only blade of the vane is located at an intermediate position between the most advanced position and the most retarded position, as shown in FIG. It is also possible to form the recess 92.

When the recess is formed in the shape of a long hole reaching from the most advanced position to the most retarded position, the depth of the recess can be made different.

That is, as shown in FIG. 11, the concave portion 102 has a gradually increasing depth linearly from the most advanced position to the most retarded position, or as shown in FIG. The concave portion 11 whose depth gradually decreases linearly toward the corner position
2. As shown in FIG. 13, it has the largest depth at an intermediate position between the most advanced position and the most retarded position, and linearly moves from this intermediate position toward the most advanced position and the most retarded position. The concave portion 122 having a gradually decreasing depth, as shown in FIG. 14, has the largest depth at the most advanced position and the most retarded position, and has a gradually increasing depth in a convex curved shape from both sides toward the intermediate position. Can be formed respectively.

By doing so, it is not necessary to perform balancing after assembling the VVT actuator by using the concave portions, so that the number of steps can be reduced, the cost can be reduced, and the balance of the entire VVT actuator can be improved. Therefore, vibration and noise from the camshaft can be reduced, and the durability and reliability of the cam journal can be improved. The weight balance from the corner side to the retard side can be arbitrarily changed, and can be set to a weight balance that matches the engine or the VVT actuator.

Further, in the first to third embodiments of the present invention, in order to eliminate the unbalance of the vane of the VVT actuator, the concave portion is provided in the body portion corresponding to the position where only the vane of the vane is disposed. However, as shown in FIG. 15, the concave portion 142 is formed on the line segment L1 passing through the rotation center C of the camshaft and the center of gravity G of the body 26, for example, in the shape of a long hole reaching from the most advanced position to the most retarded position. And a configuration (SG1) in which two opposing first and second sub-recesses 144 and 146 are provided on a line segment L2 substantially orthogonal to the line segment L1.

Then, the weight balance can be improved over the entire circumference of the VVT actuator, the vibration and noise from the camshaft can be reduced efficiently, and the durability and reliability of the cam journal portion can be improved. Further, the strength of the camshaft can be reduced, and the weight can be reduced.

Furthermore, in each of the embodiments of the present invention, when the weight balance of the VVT actuator is improved, the VVT actuator is realized by forming a concave portion in the body. (SG2) may be provided.

That is, as shown in FIG. 16, the balance correcting means 156 is provided on the first blade 154-1 functioning as a stopper of the vane 152 of the VVT actuator.

At this time, the balance correcting means 156 can be constituted by a single or a plurality of concave portions or through-hole portions in consideration of the strength of the first blade 154-1.

When the balance correcting means 156 is provided, if the amount of oil inside the VVT actuator is affected, after forming a sealed space or forming a recess or a through hole, the recess or the through hole is formed. It is also possible to take measures such as filling back the hole with another lightweight material.

Then, the vanes which disturb the weight balance of the VVT actuator can be directly corrected by the balance correcting means 156, and the weight balance of the VVT actuator can be improved.

[0073]

As described above in detail, according to the present invention, a vane type variable valve timing actuator is provided at one end of a camshaft, and a plurality of variable valve timing actuators are provided inside. A case having a chamber, a vane housed in the case and rotating integrally with the camshaft, and a body having a timing sprocket portion, and forming a plurality of blades corresponding to the chamber in the vane. In the valve train of an engine, which functions as a stopper portion and has only one large blade, in order to improve the weight balance of the variable valve timing actuator with respect to the rotational center position of the camshaft, only one blade of the vane is used. Since at least one concave portion is provided in the body portion corresponding to the arrangement position, By a recess provided in the body, it is unnecessary to perform balancing after assembling of the variable valve timing actuator and obtained reducing process, it is possible to reduce the cost, it is economically advantageous. In addition, the concave portion provided in the body can improve the balance of the variable valve timing actuator as a whole, so that vibration and noise from the camshaft can be reduced and the durability and reliability of the cam journal portion can be reduced. The strength of the camshaft can be reduced, and the weight can be reduced. Further, since the configuration can be dealt with only by forming the concave portion in the body, the configuration is simple, the manufacturing is easy, the cost can be maintained at a low cost, and it is economically advantageous.

[Brief description of the drawings]

FIG. 1 is a rear view of a body of a VVT actuator showing a first embodiment of the present invention.

FIG. 2 is a sectional view taken along line II-II of FIG.

FIG. 3 is a cross-sectional view taken along the line III-III of FIG. 1;

FIG. 4 is a rear view of a body of a VVT actuator showing a second embodiment of the present invention.

FIG. 5 is a sectional view taken along line VV of FIG. 4;

FIG. 6 is a cross-sectional view taken along line V〓-V〓 of FIG. 4;

FIG. 7 is a rear view of a body of a VVT actuator showing a third embodiment of the present invention.

FIG. 8 is a cross-sectional view taken along line V〓〓〓-V〓〓〓 of FIG. 7;

9 is a cross-sectional view taken along line 〓X-〓X in FIG. 7;

FIG. 10 is a cross-sectional view of a concave portion formed in a body of a VVT actuator showing another first embodiment of the present invention.

FIG. 11 is a sectional view of a concave portion formed in a body of a VVT actuator according to another second embodiment of the present invention.

FIG. 12 is a sectional view of a recess formed in a body of a VVT actuator according to a third embodiment of the present invention.

FIG. 13 is a sectional view of a concave portion formed in a body of a VVT actuator according to a fourth embodiment of the present invention.

FIG. 14 is a sectional view of a concave portion formed in a body of a VVT actuator according to a fifth embodiment of the present invention.

FIG. 15 is a rear view of a body of a VVT actuator showing another sixth embodiment of the present invention.

FIG. 16 is a front view of a vane of a VVT actuator showing a seventh embodiment of the present invention.

FIG. 17 is a schematic sectional front view of an engine showing the prior art of the present invention.

FIG. 18 is a schematic plan view of the engine without the cylinder head cover.

FIG. 19 is a schematic left side view of the engine with the chain cover removed.

FIG. 20 is a front view of a VVT actuator.

FIG. 21 is a sectional view taken along line XX {-XX} in FIG. 20;

FIG. 22 is a diagram illustrating a state of a VVT actuator at a most retarded position.

FIG. 23 is a diagram showing a state of a VVT actuator at a most advanced position.

FIG. 24 is a front view of a vane of the VVT actuator.

[Explanation of symbols]

 26 Body 36 Timing Sprocket 62 Main Body 64 Through Hole 66 Assembly Hole 68 Recess

Claims (6)

[Claims] 1. A vane-type variable valve timing actuator is provided at one end of a camshaft, and the variable valve timing actuator is housed in a case having a plurality of chambers therein and the case. A vane that rotates integrally with the camshaft and a body having a timing sprocket portion, and functions as a stopper portion when forming a plurality of blades corresponding to a chamber on the vane, and is a large and only one. In the valve train of an engine provided with the blades, the vane corresponds to the position of the only blade of the vane in order to improve the weight balance of the variable valve timing actuator with respect to the rotation center position of the camshaft. Characterized in that at least one recess is provided in the body part. Gin valve train. 2. The valve train for an engine according to claim 1, wherein the concave portion is formed so as to correspond to the only blade of the vane when the only blade is located at the most advanced position. 3. The valve train for an engine according to claim 1, wherein the concave portion is formed so as to correspond to the only blade of the vane when the only blade is located at the most retarded position. 4. The device according to claim 1, wherein the concave portion is formed so as to correspond to the sole vane when the sole vane is located at an intermediate position between the most advanced position and the most retarded position. Engine valve gear. 5. A vane-type variable valve timing actuator is provided at one end of a camshaft, and the variable valve timing actuator is housed in a case having a plurality of chambers therein. A vane that rotates integrally with the camshaft and a body having a timing sprocket portion, and functions as a stopper portion when forming a plurality of blades corresponding to a chamber on the vane, and is a large and only one. In order to improve the weight balance of the variable valve timing actuator in the entire circumference with respect to the rotation center position of the camshaft, the rotation center of the camshaft and the center of gravity of the body are provided. A concave portion is formed on a passing line segment and is substantially orthogonal to the line segment. A valve train for an engine, wherein two opposing first and second sub-recesses are provided on a line segment. 6. A vane-type variable valve timing actuator is provided at one end of a camshaft, and the variable valve timing actuator is housed in a case having a plurality of chambers therein and the case. A vane that rotates integrally with the camshaft and a body having a timing sprocket portion, and functions as a stopper portion when forming a plurality of blades corresponding to a chamber on the vane, and is a large and only one. The valve operating device for an engine, wherein the vane is provided with a balance correcting means on only one blade of the vane.