JPH09100704A - Valve timing control device for internal combustion engine - Google Patents

Abstract

(57) [Abstract] [PROBLEMS] To increase the amount of hydraulic oil and improve the responsiveness of the operation of the device when the engine is operating, particularly when shifting from a low speed range to a medium speed range. Has a pressure chamber 8 therein, and the tubular gear 3 as the phase conversion means is moved in the axial direction in accordance with the supply / discharge hydraulic pressure from the hydraulic circuit of the pressure chamber 8. The annular member 4 attached to the sprocket 1 is provided with a variable orifice mechanism 40. The annular member 4 has a fixed orifice 4a which communicates with the hydraulic pressure supply passage 12 and the upstream side of the pressure chamber 8, and further has a variable orifice mechanism. Variable orifices 4c and 4d forming a part of 40 are formed.
The movable valve 41 of the variable orifice mechanism 40 is moved in the radial direction by the rotational centrifugal force corresponding to the operating state of the engine, and connects or shuts off the hydraulic pressure supply passage 12 to the pressure chamber 8. For example, in the low speed rotation range, sufficient hydraulic oil is simultaneously supplied to the pressure chamber 8 from both the existing fixed orifice 4a and the variable orifices 4c and 4d to quickly shift to the medium / high speed rotation range.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a valve timing control device for variably controlling the opening / closing timing of intake / exhaust valves according to the operating state of an engine.

[0002]

2. Description of the Related Art As is well known, various valve timing control devices for internal combustion engines have been conventionally provided, and one of them is disclosed in EP 654588 shown in FIG.

The conventional apparatus shown in FIG. 6 has a sprocket 1 of a rotary body to which a rotational force is transmitted from a crankshaft of an engine through a timing chain (not shown), and intake and exhaust by the rotational force from the sprocket 1. A camshaft 2 provided with a cam for operating the valve on the outer periphery of the main body, and a phase conversion for converting the relative rotational phase between the sprocket 1 and the camshaft 2 coaxially between the sprocket 1 and the camshaft 2. A cylindrical gear 3 as a means is interposed so as to be movable in the axial direction.

The sprocket 1 has a cylindrical body 1a.
Gear part 1b around which the timing chain is wound around the rear end
Are connected by bolts 30. An annular member 4 having a stepped diameter fixed orifice 4a formed with an orifice function is fixed by caulking to the front end portion of the cylindrical main body 1a, and the annular cover 4 further includes a front cover 5 and a bolt 31. These members are integrally rotatable with the cylindrical main body 1a.

In the camshaft 2, a sleeve 6 is coaxially connected to one end of a main body 2a of the camshaft 2 by a bolt 32, and a tip end of the sleeve 6 is relatively rotatably fitted into an inner circumference of the annular member 4. doing. An inner cylinder member 7 is further coaxially fixed inside the sleeve 6.

The cylindrical gear 3 is composed of a front gear forming portion 3a and a rear gear forming portion 3b, which are divided into two in a direction substantially perpendicular to the axis at the center of the length thereof. Helical inner and outer teeth that mesh with the inner teeth 1c provided on the inner circumference of the la and the outer teeth 6a provided on the outer circumference of the sleeve 6 are formed. Both gear components 3a, 3b
Connect the pin 34 to absorb the backlash gap.
And the coil springs 35 are connected to each other while being urged toward each other through the coil spring 35. Also, this cylindrical gear 3
Is between the hydraulic pressure supplied from the hydraulic circuit in the pressure chamber 8 formed between the front gear forming portion 3a and the annular member 4, and the rear end gear forming portion 3b and the inner end surface of the gear portion 1b. It is formed so as to be movable in the left-right axial direction in the figure by the relative pressure with the spring force of the compression spring 9 mounted in the.

The pressure chamber 8 is provided on the downstream side of the fixed orifice 4a, the volume thereof increases and decreases in the axial direction, and the pressure is applied to the cylindrical gear 3 via the piston 10 arranged on the front end face of the front gear component 3a. It is designed to transmit hydraulic pressure. The piston 10 is slidably in contact with the outer peripheral surface of the sleeve 6 on the camshaft 2 side at its annular inner peripheral surface, and is movable in the axial direction.

Further, the reason why the fixed orifice 4a is provided on the upstream side of the pressure chamber 8 is to suppress the pressure fluctuation of the hydraulic oil supplied from the oil pump 11 and keep it constant, and the piston 10 keeps the hydraulic oil constant. It is possible to move or stand still without being affected by pressure fluctuations.

On the other hand, the hydraulic circuit is composed of a hydraulic pressure supply passage 12 and a hydraulic pressure discharge passage 13. The hydraulic pressure supply passage 12 connects the oil pump 11 and the pressure chamber 8 to each other, and connects the cylinder head and the camshaft main body 2a (not shown).
Between the sleeve 6 and the inner cylindrical member 7, the main passage 12a having an upstream end connected to the oil pump 11 and an upper end connected to the oil pump 11, and one end of the main passage 12a and the other end of the main passage 12a. The front cover 5 includes a curved passage 12b on the inner peripheral surface thereof and an annular passage 12c connected to the pressure chamber 8 via the fixed orifice 4a of the annular member 4. Also,
The latter hydraulic discharge passage 13 communicates the pressure chamber 8 with the outside, and has a plurality of drain passage portions 21, which continuously penetrate the peripheral walls of the lower end side of the sleeve 6 and the inner tubular member 7 along the radial direction.
22, 23, 24, a drain chamber 25 formed inside the inner tubular member 7 and communicating with each of the drain passage portions 21 to 24, and an end wall of a valve body 28 of the control valve 20 formed along the axial direction. The drain hole 25 has an axial hole 26 communicating with the drain chamber 25, and a drain hole 27 axially penetrating the wall portion of the front cover 5 to communicate the drain chamber 25 with the outside.

A control valve 20 disposed in the middle of the hydraulic pressure discharge passage 13 is provided in the inner cylinder member 7 so as to be slidable in the axial direction and selectively opens and closes each of the drain passage portions 21 to 24. A body 28 and an electromagnetic actuator (not shown) for sliding the valve body 28 in the axial direction are provided. The valve body 28 is formed in a cylindrical shape with a bottom, and the axial length thereof is set to such a length that the entire first drain passage portion 21 to the fourth drain passage portion 24 can be closed. The surface is slidably in contact with the inner peripheral surface of the inner cylindrical member 7. Also,
Coil spring 3 with one end elastically contacting the head of the bolt 32
It is urged to the left in the figure by the spring force of 7.

The electromagnetic actuator is composed of a stepping motor, and the drive rod 38 is connected to the tip end side of the rotary shaft through a mechanism for converting rotary motion into linear motion. The tip of this drive rod 38 is connected to the bottom wall of the valve body 28 via a nut 39 so that the valve body 28 can slide to a predetermined position in the horizontal axis direction in the drawing. Also,
A controller (not shown) for controlling the stepping motor has a built-in microcomputer and indicates the current operating state based on the engine speed, the intake air amount, etc. output from each sensor such as a crank angle sensor and an air flow meter. It is detecting.

Therefore, the valve element 2 is selected according to the engine operating condition.
8 is moved in the axial direction, and when any one of the drain passage portions 21 to 24 is selected and opened, the other is closed and the hydraulic pressure of the pressure chamber 8 is discharged to the outside from the selected drain passage portion. Returned to bread. Therefore, the tubular gear 3 has the pressure chamber 8
The movement position in the axial direction is controlled in multiple stages by increasing / decreasing the amount of oil. As a result, sprocket 1 and camshaft 2
The relative rotation angle of can be controlled in multiple stages.

For example, in the engine low load range, an OFF signal (not energized) is sent from the controller to the stepping motor.
Is output to move the drive rod 38 to the maximum leftward position. Therefore, the valve body 28 is held at the maximum leftward position as shown in FIG. 6, and opens the drain chamber 25 side of all the drain passage portions 21 to 24.

At this time, most of the hydraulic oil supplied from the oil pump 11 to the pressure chamber 8 through the hydraulic pressure supply passage 12 flows into the drain chamber 25 through the first drain passage portion 21, and from there, the shaft It is discharged to the outside through the direction hole 26 and the drain hole 27. Therefore, the pressure chamber 8 is in a low pressure state. For this reason, the cylindrical gear 3 has the compression spring 9
Is urged to the maximum forward position (illustrated position) by the spring force of. Thereby, the sprocket 1 and the camshaft 2
Is held at the maximum relative rotation angle position on one side to control the closing timing of the intake valve by the maximum retard angle, for example.

By the way, one of the characteristics required in such a valve timing control device is a quick response at the time of shifting from the low speed rotation range to the medium / high speed rotation range in response to the change of the engine operating state. There is a point to get. Such a response time is determined by the amount of hydraulic oil supplied to the pressure chamber 8.

[0016]

However, in the conventional apparatus shown in FIG. 6, in order to control the pressure fluctuation of the amount of oil from the oil pump 11 supplied to the pressure chamber 8, a fixed orifice is provided. The hole 4a is installed on the upstream side of the pressure chamber 8. Therefore, when the discharge pressure of the oil pump 11 is low, for example, from a low speed rotation range such as an engine speed of 1,400 rpm
In the case of rapidly shifting to a medium speed rotation range such as 2,200 rpm, there is a problem that it is difficult to obtain good responsiveness because the fixed orifice 4a limits the supply of hydraulic oil.

Therefore, if the diameter of the fixed orifice 4a is simply increased, the amount of hydraulic oil supplied to the pressure chamber 8 can be increased. However, when the high speed rotation range of 2,200 rpm or higher is reached, the discharge pressure of the oil pump 11 rises and the fixed orifice 4a diameter is increased to cause an oil leak or the like in the hydraulic oil to be increased, resulting in oil mist or blow-by. There is a problem of increasing the generation of gas.

Therefore, an object of the present invention is to increase the amount of hydraulic oil only when the engine is operating, particularly when the engine is operating in the low speed range to the medium speed range, and to improve the responsiveness of the transfer. .

[0019]

According to the first aspect of the present invention,
A rotating body that is rotationally driven by the engine, a cam shaft having a cam that operates an intake / exhaust valve by a rotating force from the rotating body, and a cam shaft that is interposed between the rotating body and the cam shaft and that is arranged in the cam shaft axial direction. Phase conversion means for converting the relative rotational phase of the rotating body and the camshaft with the movement, and the internal pressure which is formed inside the rotating body and is supplied and discharged via a hydraulic circuit. A pressure chamber for moving the phase conversion means to one side in the axial direction, and a pressure chamber which is formed in an annular member connected to one end side of the rotating body and constitutes a part of the supply passage of the hydraulic circuit. And a variable orifice mechanism for varying the passage sectional area of the variable orifice, the annular member having a variable orifice communicating with the pressure chamber and the supply passage. The .

According to a second aspect of the present invention, the variable orifice mechanism is provided with a movable valve that moves by a centrifugal force generated according to the rotation speed of the rotating body to change the passage cross-sectional area of the variable orifice. There is.

Therefore, according to the first aspect of the present invention, the variable orifice mechanism arranged in the annular member does not operate in the low speed rotation range depending on the engine operating state, and the existing fixed orifice and variable orifice are provided. And the hydraulic oil is supplied to the pressure chamber from both. By supplying a sufficient amount of hydraulic oil to the pressure chambers in this way, it becomes possible to quickly respond when shifting to the medium / high speed rotation range.

According to the second aspect of the present invention, the movable valve provided in the variable orifice mechanism is, for example, provided by the centrifugal force increased as the rotation speed increases during the transition from the medium speed rotation range to the high speed rotation range. Due to the radial movement, the communication between the movable valve and the pressure chamber is cut off, in which case hydraulic oil is supplied to the pressure chamber only from the existing fixed orifice of the annular member. Therefore, it is possible to avoid the deterioration of the valve timing characteristics due to, for example, oil mist or blow-by gas, which is increased by the increase in the hydraulic pressure due to the medium / high speed rotation.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a valve timing control device for an internal combustion engine according to the present invention will be described below with reference to the drawings. It should be noted that the same or similar components as those of the device shown in FIG. 6 of the conventional example are denoted by the same reference numerals, and the description of the overlapping portions will be appropriately omitted.

FIG. 1 shows a first embodiment of the present invention. In this first embodiment, a variable orifice mechanism 40 is attached to the annular member 4 shown in FIG. 6 to enhance its function. .

As shown in FIG. 2, which is an enlarged view of the main part of FIG. 1, one fixed orifice 4a shown in FIG. 6 of the conventional example is formed in the annular member 4, and the fixed orifice 4a At another location, at least one variable orifice mechanism 40 is incorporated circumferentially.

The variable orifice mechanism 40 includes variable orifices 4c and 4d formed through the annular member 4 in the axial direction of the camshaft, a concave portion 4b formed between the variable orifices 4c and 4d, and a slide on the concave portion 4b. A cylindrical or cylindrical movable valve 41 that moves and can move in a radial direction perpendicular to the rotation axis of the camshaft 2, and a biasing force that pushes the movable valve 41 toward the rotation axis that is the radial center. The coil spring (elastic member) 47 is provided.

The concave portion 4b is formed so as to extend from the circumferential surface of the annular member 4 in the radial direction, and penetrates the variable orifices 4c and 4d.
Of the variable orifices 4c and 4d are changed by the movable valve 41 slidingly contacting the inner surfaces of both sides of the concave portion 4b and slidingly contacting the outer peripheral surface of the movable valve 41. It has become.

The movable valve 41 has a coil spring 4 on the top.
Holding recess 42 for holding 7 and the variable orifice 4
An annular annular groove 43 communicating with c and 4d and a drain hole 44 penetrating the center along the axis of the sliding direction are formed. The groove width of the annular groove 43 is the variable orifice 4
c and 4d, the annular concave groove 43 is formed by sliding the movable valve 41 so that the variable orifices 4c and 4d are formed.
By shifting from the passage opening, the size of the passage opening can be changed and completely blocked.

Further, the coil spring 47 is held and the concave portion 4 is held.
By holding the movable valve 41 against the bottom surface of the recess 4b, that is, by holding the movable valve 41 between the shaft 2 and the cylindrical main body 1a of the sprocket 1, that is, the movable valve 41 is pressed and urged toward the camshaft rotation axis of the radial center. The set load (spring force) of the coil spring 47 is set so as to be compressed and deformed by the rotational centrifugal force of the sprocket 1 when reaching 2,200 rpm from the equilibrium state until then, depending on the relationship with the engine speed. is there. Since the movable valve 41 is slidably incorporated in the annular member 4 by such a mechanism, the rotation of the annular member 4 while the engine is operating causes the centrifugal force to be equal to or more than the set value, so that the movable valve 41 is not moved. When working, the movable valve 41 can move away from the coil spring 47 in the radial direction.

That is, in the normal position of the movable valve 41 shown in FIG. 1, the annular concave groove 43 on the movable valve 41 side is provided on the concave portion 4b side of the annular member 4 to provide the variable orifices 4c and 4d.
To communicate with the pressure chamber 8 so that the amount of hydraulic oil can be supplied to the pressure chamber 8. On the other hand, when the movable valve 41 moves,
Due to the positional displacement between the annular groove 43 and the variable orifices 4c, 4d, the hydraulic oil supplied to the pressure chamber 8 through the variable orifices 4c, 4d is throttled or completely cut off, and only from the existing fixed orifice 4a. It is configured to supply.

Next, the operation of the first embodiment having the above construction will be described. For example, in the engine low speed rotation range, the controller outputs an OFF signal (non-energized) to the stepping motor to move the drive rod 38 to the maximum leftward position. Therefore, the valve body 28 of the control valve 20 is held at the maximum leftward position as shown in FIG. 1, and opens the drain chamber 25 side of all the drain passage portions 21 to 24.

In the low speed rotation range of this engine, the working oil supplied from the oil pump 11 passes through the hydraulic pressure supply passage 12, passes through the fixed orifice 4a of the annular member 4, and is supplied to the pressure chamber 8. . At the same time, the variable orifice 4
The hydraulic oil is also supplied to the pressure chamber 8 from c and 4d. That is, the centrifugal force due to the rotation has not yet acted on the movable valve 41, and the movable valve 41 remains at the steady position in the recess 4b. In this case, the annular concave groove 43 on the movable valve 41 side is recessed 4b.
Communicating with the variable orifice holes 4c and 4d facing the above, and hydraulic oil is also supplied to the pressure chamber 8 from these variable orifices 4c and 4d. As described above, in the low speed rotation range of the engine, the hydraulic oil is simultaneously supplied to the pressure chamber 8 from both the fixed orifice 4a and the variable orifices 4c and 4d.

In this case, most of the hydraulic oil supplied to the pressure chamber 8 flows into the drain chamber 25 through the first drain passage portion 21 and from there, the axial hole 26 and the drain hole 2 are provided.
It is discharged to the outside through 7 and returned to the oil pan 39. Therefore, the inside of the pressure chamber 8 is in a low pressure state. Therefore, the tubular gear 3 is biased to the maximum forward position (leftward position in the drawing) by the spring force of the compression spring 9. As a result, the sprocket 1 and the camshaft 2 are held at the maximum relative rotational angle position on one side, and the intake valve closing timing is controlled by the maximum retard angle, for example.

On the other hand, when the engine speed increases with the shift to the medium / high speed rotation range, a large centrifugal force acts on the variable orifice mechanism 40 in the annular member 4 as the rotation speed of the sprocket 1 increases. At this time, centrifugal force acts on the movable valve 41, and the movable valve 41 moves away in the radial direction against the coil spring 47. Then, due to the movement of the movable valve 41, the annular concave groove 43 is displaced from the variable orifices 4c and 4d, the communication state up to that point is cut off, and the supply of the hydraulic oil to the pressure chamber 8 is stopped. That is, the hydraulic oil is supplied to the pressure chamber 8 only from the existing fixed orifice 4 a in the annular member 4.

The above specific example will be described with reference to FIG. 3 showing the characteristic of the oil pump discharge pressure in correlation with the hydraulic pressure of the device (VTC) and the engine speed (rpm).

In this case, the temperature of the hydraulic oil is 100 ° C.,
The operating time required for the cylindrical gear 3 to move from the maximum front position to the maximum rear position (rightward position in the figure) is 1.2 seconds at maximum.

When the number of existing fixed orifices 4a provided in the annular member 4 is set to 1, the broken line curve A in FIG.
Shows the hydraulic characteristics when the hole diameter of the fixed orifice 4a is set to 1.5 mm (hereinafter, referred to as a fixed orifice hole diameter of 1.5 for convenience), and the hydraulic oil is supplied by only one fixed orifice 4a with this hole diameter. There is.

The variable orifices 4c and 4d on the side of the recess 4b which communicates with or blocks the annular groove 43 on the side of the movable valve 41.
This variable orifice hole diameter is set to 0.5mm.
When the hole diameter obtained by adding 0.5 mm and the existing fixed orifice hole diameter of 1.5 mm is set to 2.0 mm (hereinafter, this is referred to as all orifice hole diameter 2.0 for convenience), the alternate long and short dash line B in FIG.
The hydraulic characteristics are shown when hydraulic oil is supplied to both holes simultaneously with a total orifice hole diameter of 2.0.

Therefore, the working oil pressure required to move the cylindrical gear 3 which is the phase conversion means is 2.5 kgf / c.
When m ² is set, the discharge pressure of the oil pump 11 shown by the solid line C in FIG. 3 is the set operating oil pressure 2.5 kgf / c at the initial stage of operation when the engine speed is 1,000 rpm or less.
lower than m ² . In this case, since the centrifugal force does not act on the movable valve 41 and the position remains stationary, the annular concave groove 43 and the variable orifices 4c and 4d communicate with each other, and the total orifice hole diameter of 2.0 by simultaneous supply with the existing fixed orifice 4a The hydraulic oil is supplied to the pressure chamber 8 through. When hydraulic oil is fed in this state, when the engine speed reaches 1,400 rpm, the discharge pressure C of the oil pump 11 reaches the hydraulic pressure of 2.5 kgf / cm ² required to move the tubular gear 3. Reach (sign in the figure). In other words, this means the total orifice hole diameter
By increasing the amount of hydraulic oil supplied by 2.0, it is possible to operate the cylindrical gear 3 even in a low rotation range of 1,400 rpm, and to improve the responsiveness.

On the other hand, when the cylindrical gear 3 starts to move to the right in the figure and the engine speed reaches the medium speed rotation range of about 2,200 rpm, it is necessary to supply hydraulic oil at this stage with a total orifice hole diameter of 2.0. Disappears. At this time, due to the centrifugal force acting on the movable valve 41, the movable valve 41 moves in a direction away from the radial direction, and the annular concave groove 43 and the variable orifice 4c on the concave portion 4b side,
The communication with 4d is cut off (reference numeral in the figure). That is, in the medium speed rotation range and the operating state higher than that, the working oil is supplied to the pressure chamber 8 only from the fixed orifice hole diameter 1.5 of the existing single fixed orifice 4a (reference numeral in the figure). In this way, in the operating state in the medium speed rotation range or higher, by limiting the working oil to only the fixed orifice hole diameter of 1.5, it is possible to suppress the generation of oil mist or blow-by gas due to oil leakage, for example.

Therefore, in this first embodiment, the fixed orifice 4a and the variable orifice 4c,
By supplying a sufficient amount of hydraulic oil to the pressure chamber 8 with a total orifice hole diameter of 2.0 according to 4d, quick response to the medium / high speed rotation range of the engine can be obtained.

When shifting to the medium / high speed rotation region of the engine, the annular concave groove 43 is displaced from the variable orifices 4c and 4d, and the pressure chamber 8 is moved.
When the hydraulic oil supply to the variable orifice mechanism 40 is cut off via the bent passage 12b of the hydraulic pressure supply passage 12 provided inside the front cover 5,
As shown in FIG. 2, the concave portion 4b on the annular member 4 side and the movable valve 4 are
It is discharged from the drain hole 44 to the outside through the gap 4e with the outer peripheral surface of the first nozzle.

In the first embodiment of the present invention, an example in which the variable orifice mechanism 4 is provided in the annular member 4 is shown, but the variable orifice mechanism 40 having such a structure is not limited. The second embodiment in which the variable orifice mechanism 50 shown in FIGS. 4 and 5 is provided is also possible.

The variable orifice mechanism 50 in the second embodiment is based on the annular member 4 of the conventional example shown in FIG. In this case, the oil storage chamber 5 communicated with the curved passage 12b inside the front cover 5 at a position facing the annular member 4.
1 is provided, and the entire mechanism is arranged here. That is, in the oil storage chamber 51, an elongated plate-shaped movable link 52 is rotatably supported at one end on the side closer to the camshaft rotation axis C via a support shaft pin 53, and the other end away from the radial direction is free. It is the end. The free end side is locked to the coil spring 55 via a locking pin 54.

Therefore, when the obliquely inclined posture of the movable link 52 shown by the solid line in FIG. 5 is set to the steady position, at this steady position, the variable orifice 4f separately provided in the annular member 4 is opened and the bending passage is formed. The hydraulic oil from the oil storage chamber 51 is supplied to the pressure chamber 8 through the orifice 12a and the existing one orifice 4a at the same time via 12b so that the low speed rotation range of the engine operation can be dealt with.

On the other hand, when the rotation speed of the sprocket 1 increases with the shift to the medium / high speed rotation range of the engine, centrifugal force acts on the movable link 52 of the variable orifice mechanism 50.
Due to this centrifugal force, the movable link 52 rotates against the coil spring 55 at the free end, moves to the position shown by the chain double-dashed line in FIG. 5, and the variable orifice 4f on the annular member 4 side.
Close. That is, the hydraulic oil is supplied to the pressure chamber 8 only from the existing fixed orifice 4a, and the supply amount is limited by squeezing the hydraulic oil.

[0047]

As is apparent from the above description, according to the present invention, by adopting the structure in which the variable orifice mechanism is incorporated in the conventional annular member, the engine operating state is a low speed rotation of 1,400 rpm, for example. Regardless of the range, the discharge pressure of the oil pump can reach the working hydraulic pressure required to move the cylindrical gear as the phase conversion means, and the quick response desired for this type of valve timing control device can be obtained. It can satisfy the sex.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a first embodiment of the present invention.

FIG. 2 is a partial cross-sectional front view showing a variable orifice mechanism which is an essential part of the first embodiment.

FIG. 3 is a characteristic graph showing a correlation between a device operating hydraulic pressure and an engine speed.

FIG. 4 is a longitudinal sectional view showing a second embodiment of the present invention.

FIG. 5 is a front view showing a variable orifice mechanism which is a main part of the second embodiment.

FIG. 6 is a longitudinal sectional view showing a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Sprocket (rotating body) 2 ... Cam shaft 3 ... Cylindrical gear (phase conversion means) 4 ... Annular member 4a ... Fixed orifice 4c, 4d, 4f ... Variable orifice 8 ... Pressure chamber 12 ... Hydraulic pressure supply passage 13 ... Hydraulic pressure Discharge passage 20 ... Control valves 40, 50 ... Variable orifice mechanism 41 ... Movable valve 43 ... Annular groove 52 ... Movable link

Claims (2)

[Claims] 1. A rotary body that is rotationally driven by an engine, a cam shaft having a cam that operates an intake / exhaust valve by a rotational force from the rotary body, and a rotary body that is interposed between the rotary body and the cam shaft. Phase conversion means for converting the relative rotational phase of the rotating body and the camshaft with movement of the camshaft in the axial direction, and internal liquid formed inside the rotating body and supplied and discharged through a hydraulic circuit. A pressure chamber that moves the phase conversion means to one side in the axial direction according to the pressure, and a ring member that is connected to one end side of the rotating body to form a part of the supply passage of the hydraulic circuit. And a valve timing control device for an internal combustion engine having a fixed orifice communicating with the pressure chamber, the annular member having a variable orifice communicating the pressure chamber with the supply passage, and The valve timing control apparatus for an internal combustion engine, characterized in that a variable orifice mechanism which the passage sectional area variable. 2. The variable orifice mechanism includes a movable valve that moves by a centrifugal force generated according to the rotation speed of the rotating body to change the passage cross-sectional area of the variable orifice. Valve timing control device for internal combustion engine.