JP2001227307A - Valve timing control device of internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate rotational unbalance due to provision of are revolution regulating means without making a design change to a vane member, a housing member, etc. SOLUTION: Mass distribution of a sprocket 4 is made unsymmetrical on an axis of rotation by forming a plural number of through-holes 54 by partially biasing them on the chain sprocket 4 integrally connected to a housing member 5. Arranging angles of the through-holes 54 and a revolution regulating member 9 against the axis of rotation O are made to roughly match with each other. Decrease of a moment of inertia due to provision of the through-holes 54 and increase of a moment of inertia due to provision of the revolution regulating means 9 are made to roughly match with each other. Consequently, a center of gravity of a device is roughly positioned on the axis of rotation O, and rotational unbalance is eliminated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an internal combustion engine (hereinafter referred to as "internal combustion engine").
Let's say "engine". The present invention relates to a valve timing control device for controlling the opening / closing timing of the intake valve and the exhaust valve according to the operating conditions.

[0002]

2. Description of the Related Art By rotating a mounting angle between a driving force transmitting member such as a timing pulley or a chain sprocket which rotates synchronously with a crankshaft of an engine and a camshaft having a driving cam on an outer periphery, an intake valve and a suction valve are rotated. 2. Description of the Related Art A valve timing control device for variably controlling the opening / closing timing of an exhaust valve has been conventionally devised, and this technique is disclosed in, for example, Japanese Patent Application Laid-Open No. 11-132013.

In the valve timing control device described in this publication, a vane member integrally attached to an end of a camshaft is accommodated and arranged inside a housing member integrated with a driving force transmitting member, and is provided inside the housing member. An advancing hydraulic chamber and a retarding hydraulic chamber are provided, and the vane member is rotated relative to the housing member by selectively absorbing and discharging hydraulic pressure in each of the hydraulic chambers. The opening / closing timing of the intake valve and the exhaust valve is changed by changing the rotation phase of the intake valve and the exhaust valve.

In such a so-called vane type valve timing control device, when the supply hydraulic pressure is low, for example, when the rotation speed of the engine is low, the pressure in the hydraulic chamber loses the reaction force received from the intake valve and the exhaust valve, and the vane It is known that a member is pushed by its reaction force. In order to cope with this, in the valve timing control device described in the above publication, a lock pin is provided on the vane member and the housing member as rotation restricting means for fixing a relative position between the vane member and the housing member. To prevent pushing back.

[0005]

However, in such a valve timing control apparatus in which the lock pin prevents the vane member from being pushed back, the lock pin holding portion of the vane member and the housing member and the periphery of the lock pin fitting portion are not provided. The area becomes irregular with respect to other parts due to the necessity of building up and the like, and the mass is increased accordingly. In particular, in the case where the lock pin is provided on a part of the blade of the vane member, the width of the part of the blade has to be increased in order to be able to accommodate the lock pin. Come. Therefore, the weight balance with respect to the rotating shaft is lost,
There is a problem that smooth rotation is hindered. In particular, in such a valve timing control device, since the housing member and the vane member are always rotated at a high speed by the crankshaft of the engine, the influence of the weight imbalance is very large.

[0006] This problem not only hinders the smooth rotation of the valve timing control device, but also adversely affects the camshaft and the bearing that support the valve timing control device, causing vibrations of the engine and uneven wear of components. Was likely to occur.

At present, as a countermeasure against this problem, it is conceivable to provide a padding for balance at a position on the outer peripheral surface of the housing member which is located above the weight-increased portion and the axle. Since the outer shape of the housing member increases and the overall weight increases, it is not preferable from the viewpoint of reducing the size and weight of the engine.

On the other hand, Japanese Unexamined Patent Application Publication No. 10-3
Japanese Patent No. 0411 discloses a lightening portion provided on a partition wall of a housing member which separates an advance hydraulic chamber and a retard hydraulic chamber from a vane of a vane member, thereby reducing the weight of the entire apparatus and the rotational moment. The technology of a valve timing control device for reducing the pressure is disclosed.
Japanese Patent Publication Nos. 0 and 11-101108 disclose a structure in which a lightening portion is provided at a portion corresponding to a partition wall on an outer peripheral surface of a housing member to similarly reduce the weight and reduce the rotational moment. I have.

Although these techniques are certainly effective in reducing the weight and reducing the rotational moment, in practice, the housing member has already been reduced to the limit and the wall thickness has been considerably reduced. It is difficult to provide sufficient lightening. In other words, in any of the above techniques, when the thickness of the lightening provided in the housing member is increased, the size of the partition wall is limited, and when the size of the partition wall is increased, the rotation range of the vane member is limited. Therefore, it is extremely difficult to provide sufficient lightening due to these being necks.

As a countermeasure for solving the problem of rotational imbalance caused by the addition of the lock pin, it is conceivable to use the technique described in the above-mentioned publication in which a hollow portion is provided in a housing member. In the case where the member is provided with a hollow, the problem of the size of the partition wall becomes a bottleneck as described above, and it is difficult to realize the problem.

Accordingly, the present invention has been made to solve such a problem, and the rotation associated with the provision of the rotation restricting means is provided without changing the design of the vane member, the housing member, and the like. An object of the present invention is to provide a valve timing control device for an internal combustion engine that can eliminate imbalance.

[0012]

According to one aspect of the present invention, there is provided a driving force transmitting member driven by a crankshaft of an internal combustion engine, and a driving force for operating an engine valve on an outer periphery. A camshaft that has a cam and is mounted so that the driving force transmission member can rotate relative to one another as needed, and that receives power from the driving force transmission member and is driven to rotate; and the driving force transmission member and the camshaft. A housing member that rotates integrally with one of the housing member, a vane member that is housed in the housing member, and rotates integrally with the other of the driving force transmitting member and the camshaft, and a housing member that rotates inside the housing member. An advance hydraulic chamber and a retard hydraulic chamber for rotating the vane member by hydraulic pressure, and communicating with the advance hydraulic chamber and the retard hydraulic chamber. A hydraulic suction / discharge means for selectively sucking / discharging hydraulic pressure in / from the pressure chamber; and a circuit provided between the vane member and the housing member for restricting relative rotation between the vane member and the housing member in accordance with an operation state of the internal combustion engine. A valve timing control device for an internal combustion engine, comprising: a light-weight portion provided in the driving-force transmitting member so that a mass distribution of the driving-force transmitting member is asymmetric about a rotation axis; The arrangement angle of the regulating means with respect to the rotation axis is made substantially coincident.

In the case of the present invention, the partial weight increase around the rotation axis due to the provision of the rotation restricting means is offset by the partial weight decrease by the lightweight portion of the driving force transmitting member. Therefore, it is possible to bring the center of gravity of the device closer to the rotation axis.

According to a second aspect of the present invention, the amount of reduction of the inertia moment of the driving force transmitting member due to the provision of the lightweight portion and the amount of increase of the inertia moment due to the provision of the rotation restricting means are determined. They are almost matched.

In the case of the present invention, the increase in the inertia moment due to the provision of the rotation restricting means is offset by the decrease in the inertia moment of the driving force transmitting member due to the provision of the lightweight portion. Therefore, the center of gravity of the device is located substantially on the rotation axis.

According to a third aspect of the present invention, the lightweight portion is
The drive force transmitting member is constituted by a through hole provided in a plane perpendicular to the rotation axis. According to the present invention, it is possible to form the lightweight portion in the driving force transmitting member by a simple boring process.

According to a fourth aspect of the present invention, the lightweight portion is
It is provided on a plane perpendicular to the rotation axis of the driving force transmission member,
It is constituted by a thin portion formed thinner than the general portion on the same plane. In the case of the present invention, since the lightweight portion does not completely penetrate the wall of the driving force transmission member, the rigidity of the driving force transmission member is hardly reduced.

According to a fifth aspect of the present invention, a plurality of the through holes or the thin portions are provided in substantially the same shape. In the case of the present invention, the formation is easier than forming one larger through hole or thin portion, and the rotational balance can be easily adjusted by changing the position and number of through holes or thin portions. It is possible to do.

According to a sixth aspect of the present invention, the driving force transmitting member has a larger specific gravity than a member of the housing member and the vane member which increases in weight with the addition of the rotation restricting means. Formed.

In the case of the present invention, since the specific gravity of the driving force transmitting member is large, it is possible to greatly reduce the mass even when the thickness is reduced by the same volume.

[0021]

Next, an embodiment of the present invention will be described with reference to the drawings.

FIGS. 1 to 5 show an embodiment of the present invention. In FIG. 2, reference numeral 1 denotes a camshaft of an engine. The camshaft 1 is rotatably supported by a cylinder head (not shown) via a bearing, and a drive cam (not shown) for opening and closing an intake valve as an engine valve is provided on an outer periphery of a main portion thereof. I have. The valve timing control device 2 according to the present invention is provided at one end of the camshaft 1.

As shown in FIGS. 2 and 3, the valve timing control device 1 includes a chain sprocket 4 as a driving force transmitting member that is rotationally driven by a crankshaft (not shown) via a timing chain 3; A housing member 5 integrally connected to a front end of the chain sprocket 4, the camshaft 1 having one end thereof rotatably assembled with the chain sprocket 4 and the housing member 5, and the cam; A vane member 7 integrally assembled with one end of the shaft 1 together with a sleeve 6 and rotatably housed inside the housing member 5; and a hydraulic pressure for rotating the vane member 7 forward and reverse by hydraulic pressure according to the operating state of the engine. The suction / discharge means 8 and the vane member 7 associated with the positive rotation fluctuation torque acting on the camshaft 1 Ri and according to the operating condition and a rotation restricting means 9 for regulating.

The housing member 5 includes a substantially cylindrical housing body 10 and a front cover 12 connected to front and rear end faces of the housing body 10 by bolts 11.
And a rear cover 13, and the housing body 10
As shown in FIG. 3, four partition walls 14 each having a trapezoidal cross-section are projected from the inner peripheral surface at intervals of 90 °. In addition, 1 in FIG.
Reference numerals 5a and 15b denote positioning pins for positioning the chain sprocket 4, the rear cover 13, and the housing body 10, and between the housing body 10 and the front cover 12, respectively.

On the other hand, the vane member 7 has a substantially cylindrical body 16 which is connected to the camshaft 1 together with the sleeve 6 by bolts (not shown), and a 90 ° outer circumferential surface of the body 16.
Four blades 17 radially projecting at intervals are provided, the body 16 is disposed at the axial center position of the housing member 10, and each blade 17 is disposed adjacent to the partition wall 14 of the housing member 5. It is located between them. An advancing hydraulic chamber 18 is provided between one side surface of each blade 17 of the vane member 7 and the partition wall 14 opposed thereto, and the other side surface of each blade 17 and the partition wall 14 facing the partition wall 14 are opposed to each other. The interval is defined as a retard hydraulic chamber 19. Therefore, in this device, a total of four pairs of the advance hydraulic chamber 18 and the retard hydraulic chamber 19 are provided. In addition, at the tip of each blade part 17 and the partition wall 14,
The spring-loaded seal members 20 are respectively mounted, and liquid-tightness between the adjacent hydraulic chambers 18 and 19 is achieved.

A circular recess 21 is provided on the front side of the body 16 of the vane member 7, and an end of a first radial hole 22 communicating with each of the advance hydraulic chambers 18. The ends of the second radial holes 23 communicating with the retard hydraulic chamber 19 are respectively opened on the inner peripheral surface of the recess 21. Each end of the first radial hole 22 and the second radial hole 23 is open at a position in the recess 21 that is offset in the axial direction.

A cylindrical shaft member 24 extending from a front cover (not shown) of the engine is fitted into the recess 21 of the vane member 7 so as to be relatively rotatable. Hydraulic oil is sucked and discharged from the advance hydraulic chamber 18 and the retard hydraulic chamber 19 through the shaft member 24.

As shown in FIG. 2, the hydraulic suction / discharge means 8 includes a first hydraulic passage 2 for sucking and discharging a hydraulic pressure with respect to the advance hydraulic chamber 18.
5 and a second hydraulic passage 26 that sucks and discharges hydraulic pressure to and from the retard hydraulic chamber 19.
A supply passage 27 and a drain passage 28 are respectively connected to 5 and 26 via an electromagnetic switching valve 29 for switching passages. An oil pump 31 for feeding oil in the oil pan 30 is provided in the supply passage 27, and an end of the drain passage 28 communicates with the oil pan 30. The electromagnetic switching valve 29 is controlled by a controller 32. Various signals indicating the operating state of the engine are input to the controller 32.

Reference numeral 33 in FIGS. 3 and 4 denotes a housing member 5.
A plurality of phase grooves for determining a crank angle are formed on the outer peripheral surface of the housing member 5 along the axial direction. The generated pulse changes for each crank angle. A pulse detecting device (not shown) such as a magnetic detecting element is arranged at a position close to the housing member 5, and the crank angle can be detected by detecting a generated pulse by the detecting device. . This detection signal is input to the controller 32.

The first hydraulic passage 25 has a first shaft hole 34 formed from the front cover 12 of the engine along the axial direction of the shaft member 24, and intersects the first shaft hole 34. A first radial hole 35 formed near the tip of the shaft member 24, a first annular groove 36 formed on the outer peripheral surface of the shaft member 24 so as to communicate with the first radial hole 35, The first annular groove 36 and the first radial hole 22 of the vane member 7 that communicate each advance hydraulic chamber 18 are formed. Then, the second hydraulic passage 26 is similarly connected to the shaft member 2.
4, a second radial hole 38 intersecting with the axial hole 37, and a second axial hole 37 formed along the axial direction of the axial member 4.
The second annular groove 39 formed on the outer peripheral surface of the second annular groove 4 and communicating with the second radial hole 38, and the second diameter of the vane member 7 communicating the second annular groove 39 with each of the retard hydraulic chambers 19. Direction hole 23
And is constituted by. In the case of this embodiment, the tip of the second shaft hole 37 is formed by the concave portion 21 of the vane member 7.
Although it opens toward the inside, this tip may be closed without opening.

Therefore, the advance hydraulic chamber 18 and the retard hydraulic chamber 19 inside the housing member 5 have a first hydraulic passage 25 formed from the shaft member 24 to the vane member 7 and a second hydraulic passage 25.
Hydraulic oil is selectively sucked and discharged through the hydraulic passage 26.

The rotation restricting means 9 mechanically locks the relative rotation of the housing member 5 and the vane member 7 when the rotation of the vane member 7 is controlled to the retard side when the engine is started. A lock pin 40 accommodated and supported by the vane member 7 so as to be able to advance and retreat in a radial direction, a spring member 41 for urging the lock pin 40 in a protruding direction (radially outward), and a housing member 5. And a fitting hole 42 into which the tip of the lock pin 40 is fitted at a position where the vane member 7 is displaced to the maximum in the retard direction with respect to the housing member 5.

The lock pin 40 is accommodated in one of the four blades 17 of the vane member 7. More specifically, as shown in FIG. 3, one blade 17 of the vane member 7 bulges stepwise toward the advance hydraulic chamber 18, and the outer surface of the bulge 43 extends radially. The cylinder hole 44 is formed by the
The lock pin 40 is slidably accommodated through the lock pin 40.
The collar 45 is formed of a material harder than the vane member 7 and is press-fitted and fixed so as to be biased toward the opening of the cylinder hole 44. Note that the housing member 5 is opposed to the bulging portion 43 of the vane member 7 with a set minute gap d when the vane member 7 is displaced to the maximum in the retarding direction (direction of the advance hydraulic chamber 18). A step 46 corresponding to the bulging portion 43 is provided.

The lock pin 40 is formed in a substantially cylindrical shape with a bottom as a whole. A stopper flange which can be brought into contact with an end face of the collar 45 is provided on an outer periphery of a base end accommodated in the cylinder hole 44. 47 are extended. The stopper flange 47 restricts the displacement of the lock pin 40 in the protruding direction by abutting on the end face of the collar 45, thereby preventing the pin 40 from being pulled out of the vane member 7 and moving the vane member 7 forward. This prevents the tip of the lock pin 40 from coming into contact with the inner peripheral surface of the housing member 5 when rotated to the corner side.

The lock pin 40 is formed to be hollow except for the distal end, and the spring member 41 for urging the pin 40 in the projecting direction is disposed in the hollow portion 48. And the lock pin 4 protruding from the cylinder hole 44
0 has a frusto-conical shape, and a concave surface 49 for receiving hydraulic pressure, which will be described later, is formed on the distal end surface. The weight of the lock pin 40 is also reduced by the hollow portion 48 and the depression 49. A vent hole 50 communicating the bottom of the cylinder hole 44 and the outside of the apparatus is formed in the body 16 of the vane member 7 as shown in FIG.
The bottom of 4 is maintained at atmospheric pressure.

On the other hand, the fitting hole 42 at the tip of the lock pin 40 is fitted in the housing member 5 (housing body 10).
The plug is not formed directly, but is formed on a separate plug 51 made of a hard material. The plug 51 is fitted and fixed to the step portion 46 of the housing member 5 along the radial direction. The fitting hole 42 of the plug 51
Is formed in a cup shape with a front opening so that the tip of the lock pin 40 can be fitted. The fitting hole 42 has a gap d between the step 46 and the bulging portion 43, the bottom of the fitting hole 42, Are formed. Therefore, the bottom of the fitting hole 42 is always in communication with the advance hydraulic chamber 18 through the hydraulic introduction groove 52 and the gap d.

The step 46 of the housing member 5 is
The vane member 7 rises in the axial direction from the inner peripheral surface of the general portion where the blade portion 17 is displaced, and the rising wall has a gentle taper surface 53 toward the position where the fitting hole 42 is provided. Has become. Therefore, the vane member 7
Is displaced from the advance side (the retard hydraulic chamber 19 side) to the retard side (the advance hydraulic chamber 18 side), the lock pin 40 is guided by the tapered surface 53 and smoothly retreats. In the direction, gets over the hole edge of the fitting hole 42, and is finally fitted in the fitting hole 42.

Here, in this valve timing control device, since the rotation restricting means 9 is provided between the vane member 7 and the housing member 5 as described above, the bulging portion 43 of the vane member 7 and the housing member 5 As a result, the mass distribution around the rotation axis O between the vane member 7 and the housing member 5 is not uniform but largely deviates toward the installation side of the rotation restricting means 9. I have.

In the valve timing control device 2, a through hole 54 is formed in the chain sprocket 4 connected to the rear end face of the housing member 5 in order to offset the unevenness of the mass distribution between the vane member 7 and the housing member 5. Thus, the chain sprocket 4 is partially provided with a lightweight portion.

In the case of this embodiment, the through hole 54 is formed as shown in FIG.
As shown in FIG. 3, three substantially rectangular shaped members are provided along the circumferential direction of the chain sprocket 4, and their arrangement is biased to the upper right in FIG. This through hole 54
As shown in FIG. 5, the chain sprocket 4 is formed so as to penetrate the chain sprocket 4 having a uniform thickness in the axial direction (to penetrate a plane perpendicular to the rotation axis O). It is biased obliquely downward to the left in FIG. That is, the diagonally upper right side of the chain sprocket 4 is lightened by the amount of the through hole 54.

When the chain sprocket 4 is connected to the housing member 5 as shown in FIG. 4, the through hole 54 is provided between the vane member 7 and the rotation axis O of the housing member 5 due to the provision of the rotation restricting means 9. It is provided so as to offset the unevenness of the surrounding mass distribution. More specifically, the chain sprocket 4 is attached to the housing member 5 such that the center one of the three through holes 54, 54, 54 substantially corresponds to the position where the rotation restricting means 9 is disposed, and the vane member 7 The mass increase due to the provision of the bulging portion 43 and the mass increase due to the provision of the step portion 46 in the housing member 5 are offset by the mass decrease of the through hole 54.

In this embodiment, the rotation axis O
The distance from the shaft sprocket 4 to the through hole 54 is also set accurately, and the increase in the inertia moment due to the provision of the bulging portion 43 and the step portion 46 in the vane member 7 and the housing member 5 is provided by providing the through hole 54 in the chain sprocket 4. As a result, the reduction in the moment of inertia is almost completely offset.

To explain further, the rotation axis O extends from the through hole 5
The influence of the through-hole 54 on the outer circumference of the chain sprocket 4 increases as the distance to the sprocket 4 increases. Accordingly, when the reduced mass due to the through hole 54 is ma and the distance from the rotation axis O to the center of the through hole 54 is la, the amount of reduction in the inertia moment of ma × la ² and the bulging portion 43 of the vane member 7 By matching the amount of increase in the moment of inertia due to the step 46 of the housing member 5, the valve timing control device 2
And the rotation axis O can be substantially matched.

In this embodiment, the housing member 5 and the vane member 7 are formed of an aluminum alloy, and the chain sprocket 4 is formed of an iron-based material having a higher specific gravity than the aluminum alloy. Therefore, the effect of the through hole 54 formed in the chain sprocket 4 having a large specific gravity on the entire apparatus becomes extremely large, and the opening area and the number of the through holes 54 are minimized so that the reduction in the strength of the chain sprocket 4 is minimized. It has become possible.

As described above, in this embodiment, the phase groove 33 is formed on the outer peripheral surface of the housing member 5 (housing main body 10). The portion corresponding to the arrangement position of the means 9 is set to be maximum. That is, in this embodiment, as shown in FIGS.
The phase grooves 33 on the outer peripheral surface of the housing
Are changed to 1, 2, 4, and 2, but the part where the number of arrangements is four is set to be almost at the position where the rotation restricting means 9 is disposed. Accordingly, the housing member 5 has a portion corresponding to the rotation restricting means.
Has also been partially reduced in weight.

Next, the operation of this embodiment will be described.

In this structure, when hydraulic oil is not sufficiently supplied from the oil pump 31 at the time of starting the engine, or when high-pressure hydraulic oil is supplied to the retard hydraulic chamber 19 by operating the electromagnetic switching valve 29, the vane member 7 is at the most retarded position shown in FIG. 3 with respect to the housing member 5, and the lock pin 40 of the rotation restricting means 9 is at this time set by the spring member 41.
Receiving the urging force and the centrifugal force, the distal end thereof is fitted in the fitting hole 42, and the vane member 7 and the housing member 5 are mechanically connected. For this reason, the rotational driving force input from the unillustrated crankshaft to the chain sprocket 4 via the timing chain 3 is transmitted to the camshaft via the housing member 5 and the vane member 7 which are mechanically connected in the most retarded state. 1 to open / close the intake valve at a retard timing via a drive cam (not shown). At this time, the side surface of the bulging portion 43 of the vane member 7 is maintained in a slightly separated state without contacting the side surface of the partition wall 14 facing the bulging portion 43.

When the vane member 7 is rotationally displaced to the most retarded side, the lock pin 40 is fitted into the fitting hole 42 as described above, and the housing member 5 and the vane member 7 are connected. Due to the mechanical connection, even when a positive or negative fluctuation torque is input to the camshaft 1 from the intake valve, the vane member 7 does not rotate relative to the housing member 5, and therefore, the expansion of the vane member 7. There is no problem that the protrusion 43 or the blade 17 collides with the partition wall 14 to generate a tapping sound or the like.

In this state, the advance hydraulic chamber 18 communicates with the supply passage 27 and the retard hydraulic chamber 19 communicates with the drain passage 28 under the control of the electromagnetic switching valve 29 by the controller 32. High-pressure hydraulic oil is introduced into the chamber 18, and at this time, the distal end side of the lock pin 40 (the bottom of the fitting hole 42) also passes through the gap d between the bulging portion 43 and the stepped portion 46 and the hydraulic pressure introducing groove 52. High pressure hydraulic fluid is introduced. As a result, the lock pin 40 receives the pressure of the hydraulic oil and receives the pressing force in the retreating direction, and the pressing force resists the centrifugal force acting on the lock pin 40 and the urging force of the spring member 41. Can be pushed into the cylinder hole 44 of the vane member 7. As a result, the distal end portion of the lock pin 40 is completely disengaged from the fitting hole 42 on the housing member 5 side.
Then, the mechanical rotation restriction of the vane member 7 is released.

On the other hand, each blade 17 of the vane member 7 receives a differential pressure between the advance hydraulic chamber 18 and the retard hydraulic chamber 19, and the whole vane member 7 is advanced with respect to the housing member 5 in the advance direction (the retard hydraulic chamber). 19) and stops at the most advanced position. Thereby, the chain sprocket 4 and the camshaft 1 rotate relatively, and the rotation phase of the camshaft 1 with respect to the chain sprocket 4 is controlled to the advanced side.

While the rotation phase of the camshaft 1 with respect to the chain sprocket 4 is controlled to the advance side, the high pressure of the oil pump 31 continues to act on the advance hydraulic chamber 18. As a result, it is maintained in a state of being retracted into the cylinder hole 44.

Subsequently, from this state, the controller 32
When the retard hydraulic chamber 19 communicates with the supply passage 27 and the advance hydraulic chamber 18 communicates with the drain passage 28 by the control of the electromagnetic switching valve 29, high-pressure hydraulic oil is introduced into the retard hydraulic chamber 19. At the same time, the operating oil in the advance hydraulic chamber 18 is discharged into the oil pan 30.

Thus, each blade portion 17 of the vane member 7 is
The differential pressure between the retard hydraulic chamber 19 and the advance hydraulic chamber 18 acts on
The whole vane member 7 receives this differential pressure and receives the housing member 5.
, In the retard direction (toward the advance hydraulic chamber 18). At this time, since the advance hydraulic chamber 18 facing the distal end of the lock pin 40 is set to the atmospheric pressure, the lock pin 40 projects by receiving the centrifugal force and the urging force of the spring member 41. Is restricted by the contact between the stopper flange 47 and the collar 45, the vane member 7 keeps the tip of the lock pin 40 against the housing member 5 until the lock pin 40 reaches the position of the tapered surface 53. Rotate while maintaining contact.

When the rotation of the vane member 7 with respect to the housing member 5 advances and the tip of the lock pin 40 comes into contact with the tapered surface 53, the lock pin 40 is moved to the tapered surface 53.
Is gradually guided onto the stepped portion 46, and the fitting hole 4
The second hole 42 is fitted over the second hole 42 over the edge of the second hole. As a result, the vane member 7 returns to the housing member 5 at the most retarded position.
, And the rotational phase of the camshaft 1 with respect to the chain sprocket 4 is controlled to the retard side.

Further, the valve timing control in the state of the most retarded angle and the most advanced angle has been described above.
When the first hydraulic passage 25 and the second hydraulic passage 26 are both closed by the electromagnetic switching valve when the valve is at an arbitrary position between the most retarded position and the most advanced position, the intake valve is connected to the vane member 7. Can be opened and closed at an arbitrary valve timing according to the turning position of. At this time, since the advance hydraulic chamber 18 is maintained in a closed state, hydraulic pressure acts on the tip of the lock pin 40, and the engagement of the lock pin 40 with the vane member 7 and the housing member 5 is released. Have been.

As described above, the valve timing control device 2 is rotated at a high speed by the crankshaft of the engine. In most cases, the valve timing is controlled during the high-speed rotation. Eccentricity is not preferred. However, the valve timing control device 2 of this embodiment has a plurality of through-holes 54 provided in a plane perpendicular to the rotation axis O of the chain sprocket 4 so as to be partially knitted in the circumferential direction. The distribution is made asymmetric with respect to the rotation axis, the arrangement angle of the through hole 54 and the arrangement angle of the rotation restricting means 9 are made substantially equal, and the amount of reduction of the inertia moment of the sprocket 4 due to the through hole 54 is reduced by the vane member 7 Since the amount of increase in the moment of inertia due to the provision of the bulging portion 43 and the step portion 46 in the member 5 is set to coincide with the amount of increase, the center of gravity of the device 2 is located substantially on the rotation axis O, and the rotational imbalance is reduced. Almost never occurs.

Therefore, in this device 2, the rotation balance can be properly maintained without any modification to the vane member 7 and the housing member 5. However, in this embodiment, the portion where the number of arranged phase grooves 33 on the outer periphery of the housing member 7 is the largest is substantially the rotation restricting means 9.
The phase groove 33 also contributes to the adjustment of the rotational balance. If the arrangement of the phase grooves 33 is devised as in this embodiment, the amount of partial lightening (machining) of the chain sprocket 4 can be reduced, and the reduction in rigidity of the sprocket 4 can be further reduced. .

The embodiment of the present invention is not limited to the one described above. Instead of forming the through-hole 54 as a means for providing a lightweight portion in the driving force transmitting member such as the chain sprocket 4, FIG. As shown in FIG. 7, the thin portion 55 may be provided on both front and back surfaces of the sprocket 4 or the like, or on one side surface. In the case where the lightweight portion is formed by providing the thin portion 55 in this manner, the reduction in rigidity of the drive transmission member such as the chain sprocket 4 is reduced and the deformation is reduced as compared with the case where the through hole 54 is provided. There is an advantage that it can be structured. However, in the case where a lightweight portion is formed by the through hole 54 as in the above-described embodiment,
There is an advantage that manufacturing cost can be reduced because processing is easy.

In the above-described embodiment, a plurality of substantially rectangular through holes 54 are formed in the chain sprocket 4 by knitting a part of the circumference thereof, but the through holes 154 are formed as shown in FIG. 4 may be formed only on one. In this case, there is an advantage that manufacturing can be facilitated as much as the number of through holes 154 can be reduced.

Further, as shown in FIG. 8, the through hole 254 formed in the chain sprocket 4 may be formed not in a substantially rectangular shape but in a circular shape. As can be said for the embodiment described above, the through hole 254
In the case where a plurality of (54) having the same shape are formed instead of one, the number and arrangement of the through-holes 254 (54) to be formed can be easily changed for fine balance adjustment and design change. The advantageous effect of being able to respond is obtained. In particular, when a plurality of through holes 254 as shown in FIG. 8 are formed in a circular shape, when the through holes 56 for bolt connection are drilled in the chain sprocket 4,
At the same time, there is an advantage that the through hole 254 can be easily formed by a drilling machine or the like. Therefore, the apparatus of the present invention can be obtained only by performing a simple drilling process on the existing chain sprocket 4.

In the above, an example has been described in which the chain sprocket 4 is provided with a through hole 54 and a thin portion 55 to constitute a lightweight portion. May be configured. In addition to partially providing a light-weight portion to the driving force transmitting member such as the chain sprocket 4, the rotation of the device may be balanced by changing the internal layout of the housing member 5. is there.

[0062]

As described above, the invention according to claim 1 is
The partial weight increase around the rotation axis due to the provision of the rotation restricting means is offset by the partial weight reduction by the lightweight part of the driving force transmission member, and there is no design change to the vane member or housing member. The center of gravity of the device can be brought closer to the rotating shaft without adding, so that the weight balance with respect to the rotating shaft is improved without increasing the size and weight of the device, and the operation stability of the device is improved. In addition, it is possible to prevent occurrence of vibration noise and early wear of components such as bearings. Furthermore, according to the present invention, it is not necessary to cut out the thickness of the housing member whose weight has been reduced to near the limit, so that the required strength of the housing member can be maintained.

According to the second aspect of the present invention, the increase in the inertia moment due to the provision of the rotation restricting means can be offset by the decrease in the inertia moment of the driving force transmission member due to the provision of the lightweight portion. Therefore, the rotation imbalance caused by the provision of the rotation restricting means can be almost completely eliminated.

According to the third aspect of the present invention, the lightweight portion is constituted by a through hole provided in a plane perpendicular to the rotation axis of the driving force transmitting member. There is an advantage that it can be formed by perforation and can be manufactured at low cost.

According to a fourth aspect of the present invention, the light-weight portion is provided on a plane perpendicular to the rotation axis of the driving force transmitting member, and is constituted by a thin-walled portion formed thinner than the general portion on the same plane. As a result, the rotational imbalance of the device can be eliminated without lowering the rigidity of the driving force transmitting member.

According to the fifth aspect of the present invention, since a plurality of through holes or thin portions are provided in substantially the same shape, processing is facilitated, manufacturing at low cost becomes possible, and the through holes and thin portions are formed. It is possible to easily adjust the rotational balance and change the design by changing the formation position or the number of the portions.

According to a sixth aspect of the present invention, the driving force transmitting member is formed of a member having a higher specific gravity than a member of the housing member and the vane member which increases in weight with the addition of the rotation restricting means. As a result, the rotation balance can be surely adjusted by a slight lightening process on the driving force transmitting member. The driving force transmitting member is driven by a chain or a belt, and high strength is required.The driving force transmitting member is formed of a material having a large specific gravity such as iron and a high strength, and the housing member and the vane member are formed of aluminum or the like. By being formed of a material having a small specific gravity, it is possible to simultaneously ensure sufficient strength of the driving force transmitting member and reduce the weight of the entire apparatus.

[Brief description of the drawings]

FIG. 1 is a front view of a chain sprocket showing an embodiment of the present invention, which corresponds to the arrow A in FIG. 2;

FIG. 2 is an exemplary cross-sectional view of the same embodiment taken along line CC of FIG. 3;

FIG. 3 is an exemplary sectional view taken along the line BB of FIG. 2 showing the embodiment;

FIG. 4 is an exemplary perspective view of a main part showing the embodiment;

FIG. 5 is an exemplary cross-sectional view of the same embodiment, taken along the line DD in FIG. 1;

FIG. 6 is a sectional view showing another embodiment of the present invention and corresponding to a section taken along line DD of FIG. 1;

FIG. 7 is a front view of a chain sprocket according to still another embodiment of the present invention, which corresponds to view A in FIG. 2;

FIG. 8 is a front view of a chain sprocket showing still another embodiment of the present invention, the view corresponding to the arrow A in FIG. 2;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Camshaft 2 ... Valve timing control device 4 ... Chain sprocket (driving force transmission member) 5 ... Housing member 7 ... Vane member 8 ... Hydraulic suction / discharge means 9 ... Rotation restricting means 18 ... Advance hydraulic chamber 19 ... Retard hydraulic pressure Chamber 54 ... Through hole (light part) 55 ... Thin part (light part)

Claims (6)

[Claims] 1. A driving force transmitting member driven by a crankshaft of an internal combustion engine, and a driving cam on an outer periphery for operating an engine valve so that the driving force transmitting member can relatively rotate as required. A camshaft assembled and driven to rotate by receiving power from the driving force transmitting member; a housing member rotating integrally with one of the driving force transmitting member and the camshaft; A vane member that is housed and rotates integrally with the other of the driving force transmitting member and the camshaft; an advance hydraulic chamber and a retard hydraulic pressure that are provided in the housing member and rotate the vane member by hydraulic pressure. And a hydraulic suction / discharge means communicating with the advance hydraulic chamber and the retard hydraulic chamber to selectively suction and discharge hydraulic pressure to and from these hydraulic chambers; and the vane member. And a rotation restricting means provided between the vane member and the housing member in accordance with an operation state of the internal combustion engine, the valve timing control device for an internal combustion engine comprising: The driving force transmitting member is provided with a lightweight portion so that the mass distribution of the force transmitting member is asymmetric with respect to the rotation axis, and the arrangement angles of the lightweight portion and the rotation restricting means with respect to the rotation axis are substantially matched. A valve timing control device for an internal combustion engine. 2. The method according to claim 1, wherein the amount of reduction in the inertia moment of the driving force transmitting member due to the provision of the lightweight portion is substantially equal to the amount of increase in the inertia moment due to the provision of the rotation restricting means. The valve timing control device for an internal combustion engine according to claim 1, wherein 3. The valve timing control of an internal combustion engine according to claim 1, wherein the lightweight portion is constituted by a through hole provided in a plane perpendicular to a rotation axis of the driving force transmitting member. apparatus. 4. The light-weight portion is provided on a plane perpendicular to the rotation axis of the driving force transmitting member, and is constituted by a thin portion formed thinner than a general portion on the same plane. 3. The valve timing control device for an internal combustion engine according to claim 1 or 2. 5. The valve timing control device for an internal combustion engine according to claim 3, wherein a plurality of the through holes or the thin portions are provided in substantially the same shape. 6. The driving force transmitting member is formed of a member having a higher specific gravity than a member of the housing member and the vane member which increases in weight with the addition of the rotation restricting means. The valve timing control device for an internal combustion engine according to claim 1.