JP3058080B2 - Valve timing changing device for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a leakage of fluid from a pressure chamber for changing open and close timing of a valve. SOLUTION: A phase change mechanism 11 has a housing 28 and a vane 29 provided in the inside thereof. A plurality of pressure receive parts are formed in an outer peripheral part of the vane 29, and an hydraulic chamber on advance angle side and an hydraulic chamber on delay angle side are formed on both sides of each pressure receive part, respectively. The housing 28 is fixed on a driven gear 22 provided at outer periphery of a cam shaft 12 in such a manner that it can rotate integrally. A through hole 42 which is extended in the axial direction of the cam shaft 12 on air suction side is formed in one of the pressure receive parts. A lock pin 43 is provided in the through hole 42, and a locking hole 49 in which the lock pin 43 is fitted is formed on a side face of the driven gear 22. The length around the shaft center of the cam shaft 12 on air suction side of the pressure receive part in which the through hole 42 is formed is set to be longer than the length of the other pressure receive part.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a valve timing changing device for changing the opening / closing timing of intake / exhaust valves provided in a cylinder of an internal combustion engine during operation of the engine.

[0002]

2. Description of the Related Art Conventionally, various techniques have been proposed as a technique relating to a valve timing changing device for changing the opening / closing timing of intake / exhaust valves provided in a cylinder of an internal combustion engine (for example, Japanese Patent Laid-Open Publication No. Hei 1-1-1). “Valve opening / closing timing control device” disclosed in JP-A-92504). FIG.
13 shows an example of a configuration of a conventional valve timing changing device.

As shown in FIG. 12, in this valve timing changing device, a timing pulley 202 is rotatably fitted around an outer periphery of a camshaft 201 for driving a valve. The rotational driving force is transmitted from the crankshaft of the motor. or,
A housing 203 is fixed to the timing pulley 202 so as to be integrally rotatable. Further, a vane 204 is fixed to a tip portion of the camshaft 201 so as to be integrally rotatable. A cover 206 is attached to the most distal end of the camshaft 201 so as to cover the vane 204 and the housing 203.

FIG. 13 is a sectional view taken along line XIII-XIII of FIG. 12 (note that FIG. 12 corresponds to a sectional view taken along line XII-XII of FIG. 13). As shown in the figure, the vane 204 is formed with a plurality of pressure receiving portions 205 extending radially at approximately 90 ° positions around the axis of the camshaft 201, and each pressure receiving portion 205 is provided in the housing. It is arranged in a groove 207 formed on the inner peripheral portion of 203.

In the groove 207, the pressure receiving portion 20
5, pressure chambers 208 to which oil of a predetermined pressure is supplied are provided.
209 are formed. And each pressure chamber 208,2
09, the vane 204 can be rotated relative to the housing 203 to change the rotation phase of the camshaft 201, and the valve opening / closing timing can be changed.

Further, in this valve timing changing device, as shown in FIG. 14, a through hole 210 extending in the axial direction of the camshaft 201 is formed in one of the pressure receiving portions 205. In this through-hole 210, a lock pin 211 is provided so as to be slidable coaxially. The timing pulley 202 has a locking hole 212 into which the lock pin 211 can be fitted. Lock pin 211 and cover 2
A spring 213 that biases the pin 211 in the direction of the locking hole 212 is disposed between the spring 213 and the spring 06.

The inside of the locking hole 212 and the through hole 210
A predetermined pressure of oil is supplied into a space 214 formed between the lock pin 211 and the lock pin 211.
A state in which the lock pin 211 is moved in the through hole 210 in accordance with the magnitude relationship between the hydraulic pressure and the urging force of the spring 213, and the lock pin 211 is fitted into the lock hole 212 and locked. It is possible to switch between the state where the locking is released and the state where the locking is released. When the lock pin 211 is locked by the locking hole 212, the vane 204 is locked.
As a result of the relative rotation between the motor and the housing 203 being regulated, the opening and closing timing of the valve is maintained at a predetermined timing.

[0008]

In the above-described conventional valve timing changing apparatus, each of the pressure chambers 208 and 209 is changed.
Is formed by dividing the inside of each groove 207 by each pressure receiving portion 205. That is, each pressure receiving unit 205
Is in close contact with the inner peripheral portion of the housing 203, and the side surface of each pressure receiving portion 205 is in close contact with each side surface of the timing pulley 202 and the cover 206, so that oil flows between the pressure chambers 208 and 209. It is being regulated.

However, in the pressure receiving portion 205 in which the through hole 210 is formed, the timing pulley 202 and the cover 20 have an area corresponding to the sectional area of the through hole 210.
6 and the area of contact therewith is reduced. As a result, compared to the other pressure receiving portions 205, the pressure receiving portion 205 does not have a sufficient sealing area for restricting the oil flow between the pressure chambers 208 and 209, and the pressure receiving portions 205 and May leak out. Such leakage of oil from each of the pressure chambers 208 and 209 causes a decrease in controllability in valve timing control.

The present invention has been made in view of the above circumstances, and an object of the present invention is to prevent leakage of fluid from a pressure chamber provided for changing the opening / closing timing of a valve. .

[0011]

According to a first aspect of the present invention, there is provided an image forming apparatus, comprising: a first rotating body formed of a first rotating body and a second rotating body having the same rotation axis; A plurality of protrusions extending in the radial direction of the rotation axis, a plurality of recesses formed in the second rotating body, and the protrusions being disposed in the recesses. in the circumferential direction before Symbol rotation axis Ri and a pressure chamber which is at least one side compartment formed of the protruding portion, of the camshaft for opening and closing the valve of the crankshaft preparative及 beauty the agency of the internal combustion engine One is drivingly connected to the first rotating body, the other is drivingly connected to the second rotating body, and the pressure of the fluid supplied to each pressure chamber is changed to relatively rotate the two rotating bodies. Changing the rotational phase of the camshaft with respect to the crankshaft. Wherein it is possible to change the opening and closing timing of a valve, arranged movable member before Symbol insertion space formed on one of the protruding portions, to move the same movable member in front Symbol insertion space An internal combustion engine capable of restricting the relative rotation of the two rotating bodies and holding the rotation phase of the camshaft with respect to the crankshaft at a predetermined phase by being locked by a locking portion formed on the second rotating body. In the valve timing changing device, the length of the protrusion formed with the insertion space in the circumferential direction of the rotation axis is set to be longer than the length of the other protrusion in the same direction.
The moment of inertia of each protrusion around the rotation axis.
The gist is that it is set properly . Claim
The invention described in Item 2 relates to a first rotating body and a rotating body having the same rotation axis.
The rotating shaft formed on the first rotating body of the second rotating body
A plurality of protrusions extending in the radial direction of the core;
The plurality of recesses formed, and each protruding portion is inside each recess.
Arranged in the circumferential direction of the rotation axis.
Pressure chamber defined on at least one side of the protrusion
And a crankshaft of the internal combustion engine and a valve of the engine.
One of the camshafts for opening and closing the lube
The other is driven and connected to the first rotating body, and the other is
The pressure of the fluid that is drivingly connected to the rolling element and supplied to each pressure chamber
By changing the relative rotation of the two rotating bodies,
Rotation phase of camshaft with respect to the crankshaft
To change the opening / closing timing of the valve.
It is possible to have a through-hole formed in one of the projections
The movable member is disposed in between, the insertion space of the movable member
At the locking portion formed on the second rotating body.
By stopping, the relative rotation of the two rotating bodies is regulated.
Check the rotation phase of the camshaft with respect to the crankshaft.
Valve timing change of internal combustion engine that can be maintained at a fixed phase
In the apparatus, each of the protrusions is paired with respect to the rotation axis.
And the insertion of these protrusions
In the circumferential direction of the rotation axis of the projecting portion having a space formed,
Length longer than the other protrusions in the same direction.
The gist is what has been specified.

(Operation) The operation of the present invention will be described below. In the present invention, when the pressure of the fluid supplied to the pressure chamber is changed, the rotational force acting around each of the protrusions around the rotation axis changes. As a result, the two rotating bodies rotate relatively. The rotation phase of the camshaft with respect to the crankshaft is changed by this relative rotation, and the opening / closing timing of the valve is changed.

The movable member disposed in the insertion space of the first rotating body is driven by the driving means and moves in the space. Then, when the movable member is locked by the locking portion formed on the second rotating body, the relative rotation of both rotating bodies is regulated.
As a result, the rotational phase of the camshaft with respect to the crankshaft is maintained at a predetermined phase, and the valve opening / closing timing is maintained at a predetermined timing.

The pressure chamber is formed by dividing the inside of a concave portion formed in the second rotating body by each protruding portion. Each projection serves as a sealing member to suppress leakage of fluid from the pressure chamber. Here, the protrusion in which the insertion space is formed has a longer length in the circumferential direction of the rotation axis than the protrusion in which the space is not formed. As a result, in the protruding portion in which the insertion space is formed, the length of the seal for sealing the pressure chamber is increased, and leakage of the fluid from the pressure chamber is suppressed.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION

(First Embodiment) Hereinafter, a first embodiment in which the present invention is embodied as a valve timing changing device provided in a multi-cylinder gasoline engine as an internal combustion engine will be described.

FIG. 1 shows an intake camshaft 12 provided with a phase change mechanism (hereinafter referred to as a “VVT mechanism”) 11.
FIG. Incidentally, the intake side camshaft 12 corresponds to the camshaft in the present invention.

Journal 12 of intake side camshaft 12
a is rotatably supported by the upper end surface of the cylinder head 18 and the bearing cap 19. As shown in FIG. 3, four sets of a pair of cams 20 are formed on the outer peripheral portion on the base end side (the right side in FIG. 1) of the intake side camshaft 12. An upper end of an intake valve (not shown) provided for each cylinder is in contact with each cam 20.
The intake valve is opened and closed by the rotation of.

In the camshaft 12 on the intake side, an enlarged diameter portion 21 is formed at a portion on the tip side (left side in FIG. 1) from the portion supported by the cylinder head 18 and the bearing cap 19. An annular driven gear 22 is rotatably fitted on the outer periphery of the enlarged diameter portion 21. A plurality of external teeth 22a are provided on the outer peripheral portion of the driven gear 22.
The external teeth 22a are meshed with the external teeth 24a of a drive gear 24 provided on the exhaust-side camshaft 23 as shown in FIG. 3 (the drive gear 24 is not shown in FIG. 1). doing).

The exhaust camshaft 23 is formed with four pairs of cams 25 similarly to the intake camshaft 12. An exhaust valve (not shown) is opened and closed by these cams 25. A cam pulley 26 is fixed to an end of the exhaust side camshaft 23, and a timing belt 27 is mounted on the pulley 26. The timing belt 27 is mounted on a crank pulley (not shown) attached to a crankshaft (not shown) of the engine.

When the operation of the engine is started, the rotational driving force of the crankshaft is transmitted to the exhaust side camshaft 23 via the cam pulley 26, and the rotational driving force is transmitted to the drive gear 24 and the driven gear 22.
And transmitted to the intake-side camshaft 12 via the

FIG. 4 is a sectional view taken along line IV-IV of FIG. 1 (FIG. 1 corresponds to a sectional view taken along line II of FIG. 4). As shown in FIG. 4, the VVT mechanism 11 includes a housing 28 and a vane 29 as a first rotating body disposed in the housing 28.
And an advance hydraulic chamber 13 and a retard hydraulic chamber 14 for applying a rotational force in the direction around the axis of the intake camshaft 12 to rotate the vane 29.

The housing 28 has a substantially hollow disk shape as a whole, and its side surface is brought into contact with the front end side surface (the left side surface in FIG. 1) of the driven gear 22 and is formed by a plurality of bolts 30 to be described later. The cover 22 is fixed to the gear 22 together with the cover 38. Therefore, the housing 28, the driven gear 22, and the cover 38 are connected to the intake camshaft 1
2 can be integrally rotated about the rotation axis. In the present embodiment, the housing 28 and the driven gear 2
Reference numeral 2 corresponds to a second rotating body.

The vane 29 includes an annular fixed portion 31 located at the center thereof, and four pressure receiving portions 32 formed on the outer periphery of the fixed portion 31. Each pressure receiving section 32
The intake camshaft 12 extends radially in the radial direction and has a substantially cross shape as a whole. The pressure receiving portions 32 are symmetrically arranged with respect to the axis of the intake camshaft 12. Each pressure receiving portion 32 corresponds to a protruding portion in the present invention.

Inside the housing 28, a predetermined distance is set in the circumferential direction of the camshaft 12 on the intake side.
Four protrusions 33 protruding toward the axis of the shaft 12
Are formed. The inner peripheral surface of each of the projections 33 is in sliding contact with the outer peripheral surface of the fixed portion 31.

In the housing 28, grooves 34 are formed between the projections 33, respectively.
A recess 51 is defined by the inner peripheral wall of the housing 28 and the front end surface of the housing 28 and the enlarged diameter portion 21. Each pressure receiving section 3
2 is disposed in the concave portion 51, and both side surfaces thereof are in sliding contact with the cover 38, the driven gear 22, and the enlarged diameter portion 21, respectively, as shown in FIG. The outer peripheral surface of each pressure receiving portion 32 is in sliding contact with the inner peripheral surface of the housing 28.

An outer peripheral groove 35 having a rectangular cross section is formed in the outer peripheral portion of each pressure receiving portion 32. As shown in FIG. 7, seal members 36 are provided in the outer peripheral grooves 35, respectively.
Further, each seal member 36 is urged toward the outer peripheral side by a leaf spring 37. As a result, the outer peripheral surface of the pressure receiving portion 32 and the inner peripheral surface of the housing 28 are sealed by the seal member 36, and the advanced hydraulic chamber 13 and the retard hydraulic chamber 14 are sealed.
The movement of oil between them is regulated.

At the tip of the intake side camshaft 12,
A disk-shaped cover 38 is provided so as to cover the front end side surfaces of the housing 28 and the vane 29. At the center of the cover 38, a mounting hole 39 is formed.

A center hole 4 is provided at the center of the fixing portion 31.
0 is formed. The mounting bolt 84 inserted into the center hole 40 is connected to the bolt hole 4 of the intake side camshaft 12.
By screwing in at 1, the vane 29 is fixed to the tip of the intake-side camshaft 12. Further, the vane 29 and the intake side camshaft 12 are engaged by a knock pin (not shown), so that the two 29 and 12 rotate integrally.

The space surrounded by the inner peripheral wall of each of the recesses 51 and the cover 38 is divided into two pressure chambers by the pressure receiving portions 32. The pressure chamber formed on the same side as the rotation direction (shown in FIG. 4) of the intake side camshaft 12 is a retard side hydraulic chamber 14 and is formed on the side opposite to the rotation direction. The pressure chamber thus set is the advance side hydraulic chamber 13.

Oil is supplied to the interior of each of the hydraulic chambers 13 and 14 through advance-side and retard-side hydraulic passages P1 and P2, which will be described later, and the vane 29 acts on the pressure receiving portion 32. Depending on the magnitude of the oil pressure in each of the hydraulic chambers 13 and 14, the same direction as the rotation direction of the intake-side camshaft 12 (hereinafter, this rotation direction is referred to as "advance rotation direction") or It is possible to rotate in a direction opposite to the rotation direction (hereinafter, this rotation direction is referred to as “retarded rotation direction”).

As shown in FIG. 6, a through-hole 42 having a circular cross section extending in the axial direction of the intake-side camshaft 12 is formed in one of the pressure receiving portions 32, and a lock pin 43 is provided in the through-hole 42. Are arranged. More specifically, the through-hole 42 has a step portion 42a in the middle thereof, and has a shape in which a portion on the tip side (left side in FIG. 6) of the step portion 42a is expanded in diameter. In this embodiment, the through hole 42 corresponds to an insertion space, and the lock pin 43 corresponds to a movable member.

The lock pin 43 has a cylindrical shape with a bottom, and an enlarged diameter portion 43a is formed at a tip portion thereof. The lock pin 43 moves in the axial direction of the intake-side camshaft 12 with its outer peripheral surface slidingly contacting the inner peripheral surface of the through hole 42.

A hydraulic chamber 44 for releasing the locked state of the lock pin 43 is defined by an annular space surrounded by the inner peripheral side surface of the through hole 42 and the outer peripheral side surface of the lock pin 43. I have. The hydraulic chamber 44 communicates with a later-described advance-side annular passage 46 via a first pressure oil passage 45 formed inside the vane 29.

An accommodation hole 47 extending in the axial direction is formed inside the lock pin 43, and a spring 48 as urging means is provided in the hole 47. The spring 48 biases the lock pin 43 toward the proximal end of the intake camshaft 12.

On the tip side surface of the driven gear 22,
At the position facing the base end face of the lock pin 43, the pin 4
Locking hole 49 as a locking portion into which the base end portion of 3 can be fitted.
Are formed. When the lock pin 43 urged by the spring 48 fits into the locking hole 49, the relative rotation between the vane 29 and the driven gear 22 is restricted. As a result, the intake-side camshaft 12, the vane 29, the driven gear 22, and the housing 28 rotate integrally. As shown in FIGS. 9 and 10, a locking hole 49 is provided in a second pressure oil passage 5 formed on a side portion of the pressure receiving portion 32.
0 communicates with one of the retard side hydraulic chambers 14.

When the lock pin 43 is locked in the lock hole 49, the vane 29 is positioned at the position where the rotational phase of the intake camshaft 12 shown in FIG. Hereinafter, the position of the vane 29 is referred to as a “most retarded position”) and is fixed at a position advanced by about 2 ° CA (crank angle) as shown in FIG. In this embodiment, a driving means is constituted by the locking hole 49, the hydraulic chamber 44, the first pressure oil passage 45, the second pressure oil passage 50, and the spring 48.

FIG. 8 is a front view showing only the vane 29. In the present embodiment, of the pressure receiving portions 34 formed in the vane 29, the length of the pressure receiving portion 32 (hereinafter referred to as “pressure receiving portion A”) in which the through hole 42 is formed around the axis of the intake-side camshaft 12. The other three pressure receiving parts 3
2 (hereinafter referred to as “pressure receiving portion B”). That is, as shown in FIG.
The length L1 of the pressure receiving portion A32, which is equidistant from the axis 2 (the position is indicated by C in the figure), is equal to the pressure receiving portion B3.
2 are longer than the lengths L2 to L4 (L2 = L3 = L4) (FIG. 8 shows only the lengths L1 to L4 at the distances r1, r2, and r3).

Further, as described above, the length L1 of the pressure receiving portion A32
Is set so that the moment of inertia of each pressure receiving portion B32 around the axis C becomes equal.

More specifically, although the lock pin 43 and the spring 48 are disposed in the through hole 42 as described above, the hydraulic pressure chamber 44 and the lock Since the hollow portion such as the accommodation hole 47 of the pin 43 is formed, the inertia moment is reduced by an amount corresponding to the inertia moment of the hollow portion. Therefore, in the present embodiment, the length L1
Is set to be long, the decrease in the inertia moment is offset, and the inertia moment of the pressure receiving portion A32 is made equal to the other pressure receiving portions 32.

Next, the advance-side and retard-side hydraulic passages P1 and P2, which constitute a pressure passage for supplying oil to the advance-side hydraulic chamber 13 and the retard-side hydraulic chamber 14, and the OCV 16
The following describes the configuration.

As shown in FIG. 1, the advance head oil passage 53 and the retard head oil passage 5 are provided inside the cylinder head 18.
4 are formed. Each of the head oil passages 53 and 54 is
An oil pan 57 can be connected via the CV 16, the oil filter 55, the oil pump 15, and the oil strainer 56. When the oil pump 15 is driven with the operation of the engine, the oil stored in the oil pan 57 is sucked by the pump 15. Then, the oil is introduced into the oil pump 15 via the oil strainer 56, and is pressurized and discharged from the pump 15. The discharged oil is supplied to the oil filter 55.
Each of the head oil passages 53, 5 by the OCV 16 through the
4 to be selectively pumped.

Oil grooves 58, 59 are formed in the upper end portion of the cylinder head 18 and the bearing cap 19 so as to surround the outer periphery of the journal 12a, and the head oil passages 53, 54 are formed in the respective oil grooves 58. , 59.

A retard-side shaft oil passage 60 extending in the axial direction is formed inside the intake-side camshaft 12, and its tip end communicates with the bolt hole 41.
A circumferential groove 6 extending in the circumferential direction is formed on an outer peripheral portion of the enlarged diameter portion 21.
1 is formed, and the groove 61 and the distal end side of the retard-side shaft oil passage 60 are communicated by a communication oil passage 62.

A retard-side oil hole 63 extending in the radial direction of the intake-side camshaft 12 is formed inside the journal 12a. The retard shaft oil passage 60 communicates with the one oil groove 59 through the retard oil hole 63.

Further, inside the intake side camshaft 12,
An advanced shaft oil passage 64 extending in a direction inclined with respect to the axial direction is formed. An advance-side oil hole 65 extending in the radial direction of the intake-side camshaft 12 is formed inside the journal 12a. The proximal end side of the advance shaft oil passage 64 communicates with the other oil groove 58 through the advance oil hole 65.

As shown in FIG. 1, the driven gear 22 is formed with four cut grooves 66 having a fan-shaped cross section.
The peripheral groove 61 and each retard side hydraulic chamber 14 are formed by each cut groove 66.
And are communicated.

As shown in FIG. 1, a cylindrical protruding portion 67 protruding toward the distal end is formed on the distal end side surface of the enlarged diameter portion 21. A step portion 68 is formed on the base end portion of the vane 29 so as to surround the projecting portion 67. The space formed by the inner peripheral wall of the step portion 68 and the projecting portion 67 and the enlarged diameter portion 21 forms a ring-shaped advance-side annular passage 46. The leading end of the advance shaft oil passage 64 opens into the advance annular passage 46.

Further, as shown in FIG. 4, four advance-side supply oil holes 69 extending radially are formed inside the vane 29, and the inner peripheral side of the oil hole 69 is the advance-side oil supply hole 69. It leads to an annular passage 46. The outer peripheral side of each advance side supply oil hole 69 is open to each advance side hydraulic chamber 13 described above.

As described above, the advance side head oil passage 53 and the oil groove 5
8, the advance-side oil hole 65, the advance-side shaft oil passage 64, the advance-side annular passage 46, and each advance-side supply oil hole 69 constitute an advance-side hydraulic passage P1. Oil passage 5
4. Oil groove 59, retard side oil hole 63, retard side shaft oil passage 6
0, the communication oil passage 62, the circumferential groove 61, and each of the cut grooves 66 constitute a retard side hydraulic passage P2.

In the present embodiment, oil is supplied from the oil pump 15 into the hydraulic chambers 13 and 14 by switching the communication state between the hydraulic paths P1 and P2 and the oil pump 15 and the oil pan 57 by the OCV 16, Alternatively, the oil may be discharged from the hydraulic chambers 13 and 14 and the oil pan 57 may be discharged.
To return to. The hydraulic passages P1, P
2. The fluid supply means is constituted by the oil pump 15 and the OCV 16.

The opening of the OCV 16 is duty-controlled, so that the advance side and the retard side hydraulic chambers 13,
14 is for controlling the hydraulic pressure supplied to 14. Hereinafter, the configuration of the OCV 16 will be described.

As shown in FIG. 1, the casing 70 constituting the OCV 16 has first to fifth ports 71 to 75. The first port 71 is in communication with the advance side head oil passage 53, and the second port 72 is in communication with the retard side head oil passage 54. Also, the third and fourth ports 73, 74
Is connected to an oil pan 57, and the fifth port 75 is connected to the discharge side of the oil pump 15 via an oil filter 55.

A skewer-shaped spool 76 is provided inside the casing 70. This spool 76 has four cylindrical valve bodies 77, and can reciprocate in its axial direction. The casing 70 is provided with an electromagnetic solenoid 78 for moving the spool 76 between a first operating position shown in FIG. 1 and a second operating position shown in FIG. A spring 79 is provided in the casing 70, and the spring 79
Are biased toward the first operating position.

The OCV 16 is controlled by an electronic control unit (hereinafter referred to as "ECU") 17 shown in FIG. The ECU 17 is connected to a rotation speed sensor 80 and an intake pressure sensor 81 for detecting an operating state of the engine, and a crank angle sensor 82 and a cam angle sensor 83 for detecting a rotation phase of the intake camshaft 12. And E
CU17 is based on the detection signal of each sensor 80-83,
The operating state of the engine and the rotational phase of the intake camshaft 12 are detected. And ECU1
7 determines a deviation between an actual rotation phase of the intake-side camshaft 12 and a target rotation phase suitable for the operating state of the engine, and sets the OC so that the deviation becomes a predetermined value or less.
V16 is controlled. Note that the ECU 17 in the present embodiment is
Is equivalent to control means.

Next, the operation of the present embodiment configured as described above will be described. When the operation of the engine is started, the oil pump 15 is driven to
The oil is discharged from. The discharged oil is the OCV16
Is supplied from one of the hydraulic passages P1 and P2 selected into the hydraulic chambers 13, 14 of the advance hydraulic chamber 13 or the retard hydraulic chamber 14. At this time, the first pressure oil passage 4 is provided inside the hydraulic chamber 44 or the locking hole 49.
5 or the oil is supplied through the second pressure oil passage 50.

When the oil pressure in the oil pressure chamber 44 or the locking hole 49 increases to a predetermined value or more, the lock pin 43 resists the urging force of the spring 48 by the oil pressure, and the leading end of the camshaft 12 on the intake side. Go to By this movement, the locking of the vane 29 is released as shown in FIG. 6, and the relative rotation of the vane 29 with respect to the housing 28 becomes possible.

Then, as shown in FIG.
9, the discharge side of the oil pump 15 communicates with the advance-side head oil passage 53, and the retard-side head oil passage 54 communicates with the oil. The pan 57 is communicated. Therefore, each advance side hydraulic chamber 13
Is supplied via the advance hydraulic passage P1, while the oil in each retard hydraulic chamber 14 is returned to the oil pan 57 via the retard hydraulic passage P2.

As a result, the pressure receiving portion 32 is energized by the hydraulic pressure in each advance hydraulic chamber 13 which is relatively increased from the hydraulic pressure in each retard hydraulic chamber 14. 5 rotates in the advance rotation direction indicated by the arrow in FIG. By rotating the vane 29 with respect to the housing 28 in this manner, the rotational phase of the intake-side camshaft 12 advances more than the driven gear 22, so that the opening and closing timing of the intake valve is advanced.

On the other hand, as shown in FIG.
When the spool 76 is arranged at the first operating position by the urging force of the above, the discharge side of the oil pump 15 communicates with the retard head oil passage 54, and the advance head oil passage 53 and the oil pan 57 are connected. Communicated. Accordingly, oil is supplied to each of the retard hydraulic chambers 14 through the retard hydraulic passage P2, while oil in each of the advance hydraulic chambers 13 is returned to the oil pan 57 through the advance hydraulic passage P1. It is.

As a result, each of the pressure receiving sections 32 is provided with a corresponding one of the retard angle side hydraulic chambers 1 which has been relatively increased from the hydraulic pressure of each advance side hydraulic chamber 13.
Since the vane 29 is urged by the oil pressure in the housing 4, the vane 29 rotates relative to the housing 28 in the retard rotation direction indicated by the arrow in FIG. 4. The rotation of the vane 29 with respect to the housing 28 causes the rotation phase of the intake-side camshaft 12 to lag behind that of the driven gear 22. As a result, the opening / closing timing of the intake valve is delayed.

As described above, the intake-side camshaft 1
When the rotation phase of the OCV 16 is changed and the deviation between the rotation phase and the target rotation phase adapted to the operating state of the engine becomes equal to or smaller than a predetermined value, the ECU 17 sets the first port 71 and the second port 72 of the OCV 16 to both ports. The spool 7 is moved so that 71 and 72 are closed by the valve body 77.
The position of the spool 6 is controlled (hereinafter, the position of the spool 76 is referred to as an “intermediate holding position”). Thus, the spool 76
When the position of the hydraulic chamber 13 becomes the "intermediate holding position",
The supply of oil to the hydraulic chamber 4 and the discharge of oil from the hydraulic chambers 13 and 14 are not performed. Since each pressure receiving portion 32 is held from both sides by the hydraulic pressure in each of the hydraulic chambers 13 and 14, the rotation of the vane 29 is restricted and the housing 28
, The position of the vane 29 in the rotation direction is fixed. As a result, the opening / closing timing of the intake valve is maintained at a predetermined timing.

As described above, in the valve timing changing apparatus according to the present embodiment, the opening / closing timing of the intake valve is continuously (steplessly) changed by controlling the opening of the OCV 16 and the opening / closing timing is controlled. Can be held.

Further, in the present embodiment, when the engine is in a predetermined operating state, the lock pin 43 is locked by the locking hole 49, so that the relative rotation between the vane 29 and the housing 28 is reduced. The position is regulated, and the position of the vane 29 in the rotation direction is fixed at a position near the “most retarded position” shown in FIG.

More specifically, when the engine stops, the spool 76 of the OCV 16 moves to the first operating position shown in FIG. As a result, each advance-side hydraulic chamber 13 communicates with the oil pan 57 through the advance-side hydraulic passage P1, and each retard-side hydraulic chamber 14 communicates with the discharge side of the oil pump 15 through the retard-side hydraulic passage P2. Is done. When the rotation of the crankshaft stops, the discharge of oil from the oil pump 15 stops, and further,
The rotation of the intake camshaft 12 also stops. At this time, the vane 29 rotates relative to the driven gear 22 in the retarded rotation direction, and its rotation phase is delayed. as a result,
The position of the vane 29 in the rotation direction with respect to the housing 28 is a position near the “most retarded position”. This is because the oil is not discharged from the oil pump 15 and the hydraulic pressure in each of the advance hydraulic chamber 13 and the retard hydraulic chamber 14 decreases,
This is because each pressure receiving portion 32 is not held by the hydraulic pressure of each hydraulic chamber 13, 14.

Further, when the operation of the oil pump 15 is stopped, the hydraulic pressure in the hydraulic chamber 44 and the locking hole 49 decreases. As a result, the lock pin 43 is moved toward the base end of the intake camshaft 12 by the urging force of the spring 48, and the base end of the lock pin 43 is moved to the locking hole 4 as shown in FIG.
9.

Accordingly, the relative rotation between the vane 29 and the driven gear 22 is restricted, and the opening / closing timing of the intake valve is fixed to a state slightly advanced from the state most delayed from the rotational phase of the crankshaft. In the present embodiment, the operation of the engine is started again, and the opening / closing valve timing of the intake valve is held in that state until the hydraulic pressure in each of the hydraulic passages P1 and P2 becomes a predetermined value or more.

The embodiment described above has the following features. (A) In the present embodiment, the pressure receiving portion A32 in which the through hole 42 is formed has a length L1 around the axis of the intake camshaft 12 set to be longer than the length L2 of the other pressure receiving portion B32. I have. Accordingly, the distance between the hydraulic chambers 13 and 14 formed on both sides of the pressure receiving portion A32 is greater than the distance between the hydraulic chambers 13 and 14 formed on both sides of the other pressure receiving portion B32. Then, as a result of an increase in the sealing area where the pressure receiving portion A32 contacts the housing 28 or the cover 38, leakage of oil from the hydraulic chambers 13 and 14 can be prevented. Further, since the movement of oil between the hydraulic chambers 13 and 14 is prevented, it is possible to prevent a decrease in controllability when controlling the opening / closing timing of the valve.

(B) In the present embodiment, the length L1 of the pressure-receiving portion A32 around the axis of the intake-side camshaft 12 is set longer than the length L2 of the other pressure-receiving portion B32, thereby forming the inside thereof. The inertia moment around the axis is equalized for each of the pressure receiving portions 32 by offsetting the reduction in the inertia moment due to the hollow portion.

If the moment of inertia about the axis differs in each pressure receiving portion 32, when the vane 29 rotates together with the intake side camshaft 12, the shaft 1
2 has a centrifugal force proportional to the rotation speed of the vane 29.
At the position where is provided. When such a centrifugal force acts on the intake side camshaft 12, the shaft 12 may be deformed by the centrifugal force. Therefore, it is necessary to increase the diameter of the shaft 12 to increase its rigidity. However, such a design change undesirably increases the manufacturing cost.

In the present embodiment, all the pressure receiving portions 32 have the same moment of inertia, and the pressure receiving portions 32 are arranged symmetrically with respect to the axis of the intake camshaft 12.
No centrifugal force acts on the intake side camshaft 12 from the vane 29. Therefore, it is not necessary to increase the diameter of the intake side shaft 12, and it is possible to avoid an increase in manufacturing cost as described above.

(Second Embodiment) Next, a second embodiment of the present invention will be described with reference to FIG.
This embodiment is different from the configuration of the first embodiment in that a configuration in which the VVT mechanism 11 is provided on the exhaust-side camshaft 23 is employed.

The VVT mechanism 11 in the present embodiment,
And the structure of the advance-side and retard-side hydraulic passages P1, P2 for supplying oil to the advance-side and retard-side hydraulic chambers 13, 14 formed in the mechanism 11, or the OCV 16, etc. Are the same as those in the first embodiment, and the description thereof will be omitted.

As shown in FIG. 11, a cam pulley 26 is fixed to one end of the exhaust-side camshaft 23 so as to be integrally rotatable, and a timing belt 27 is mounted around the outer periphery of the pulley 26. On the exhaust side camshaft 23,
The timing belt 27 transmits the rotational driving force of the crankshaft.

The other end of the exhaust side camshaft 23 has VV
The T mechanism 11 is attached. The mechanism 11 includes the driven gear 22 described in the first embodiment,
A drive gear 91 as a second rotating body is provided. Further, external teeth 92a are provided at the end of the intake side camshaft 12.
The driven gear 92 is provided, and the external teeth 92 a are meshed with the external teeth 91 a of the drive gear 91.

According to the present embodiment having the above configuration, the rotational driving force of the crankshaft is controlled by the exhaust-side camshaft 23.
And transmitted from the shaft 23 to the intake-side camshaft 12 via the drive gear 91 and the driven gear 92. Then, the intake side camshaft 12
The intake valve (not shown) is opened and closed by the cam 20 with the rotation of. In the present embodiment, the intake camshaft 12 corresponds to the camshaft of the present invention.

The relative rotation phase of the drive gear 91 with respect to the exhaust camshaft 23 is changed by the VVT mechanism 11. Therefore, the rotation phase of the intake camshaft 12 with respect to the crankshaft is changed, and the opening / closing timing of the intake valve is changed.

This embodiment has the same configuration as that of the first embodiment except that the valve opening / closing timing of the intake camshaft 12 without the VVT mechanism 11 is changed. I have. Therefore, this embodiment is
It has the same function as the above embodiment, and has the same features as those described above.

Each of the embodiments described above can be implemented by changing the configuration as follows. (1) In the above embodiments, the vane 29 is fixed to the intake-side camshaft 12, and the housing 28 is fixed to the driven gear 22 or the drive gear 91. However, the following configuration may be adopted. . That is, the vane 29 is fixed to the driven gear 22 or the drive gear 91 so as to be integrally rotatable, while the housing 28 is fixed to the intake side camshaft 12 so as to be integrally rotatable. And
A hole corresponding to the through hole 42 is formed in the housing 28, a lock pin is provided in the hole, and the lock pin is locked by a locking hole 49. With such a configuration, the same operation and effect as those of the above embodiment can be obtained.

(2) In each of the above embodiments, the locking portion in the present invention is constituted by the locking hole 49. However, the locking hole 49 is omitted, and the base end surface of the lock pin 43 is connected to the driven gear 22. Alternatively, the relative rotation between the vane 29 and the housing 28 may be regulated by pressing the front side surface of the drive gear 91 by the urging force of the spring 48. Further, the rotation of the vane 29 and the housing 28 may be restricted by the plurality of lock pins 43 and the locking holes 49.

(3) In the first embodiment, the VVT mechanism 1 has a structure in which the driven gear 22 is changed to a cam pulley and a timing belt is mounted on the pulley.
1, the pulley may be directly driven to rotate by the rotation driving force of the crankshaft.

(4) In each of the above embodiments, the structure in which the four pressure receiving portions 32 are formed in the vane 29 is employed. However, a configuration in which three or less or five or more pressure receiving portions 32 are provided may be adopted. it can. When the number of the pressure receiving portions 32 is smaller than that in each of the above embodiments, the configuration of each of the hydraulic passages P1 and P2 can be simplified. A large rotation torque can be applied.

(5) In each of the above embodiments, the housing 28 and the driven gear 22 or the drive gear 91 are constituted by separate members. However, for example, they may be constituted integrally. Similarly, the intake side camshaft 12 and the vane 29 may be configured integrally.

(6) In each of the above embodiments, the VVT mechanism 11 having a configuration in which the cam pulley 26 is changed to a timing sprocket and the timing belt 27 is changed to a timing chain may be adopted.

(7) In each of the above embodiments, the opening / closing timing of the intake valve is changed. However, the opening / closing timing of the exhaust valve may be changed.
Further, the VVT mechanism 11 may be provided on both the intake side camshaft 12 and the exhaust side camshaft 23 to change the valve opening / closing timing of both the intake valve and the exhaust valve.

The embodiments embodying the present invention have been described above. The technical ideas that can be grasped from the above embodiments, together with their effects, will be described below. (A) In the valve timing changing device for an internal combustion engine according to claim 1, each protruding portion is formed on the first rotating body so as to be located symmetrically with respect to the rotation axis, and By making the length in the circumferential direction of the rotation axis of the protruding portion in which the insertion space is formed longer than the length of the other protruding portions at positions symmetrical to the protruding portion, around the rotation axis center A valve timing changing device for an internal combustion engine, wherein inertia moments of both protruding portions are set to be equal.

According to the configuration described in the above (A), the first
When the rotating body rotates around the rotation axis, the centrifugal force due to the moment of inertia of the two protruding portions is canceled out, so that the centrifugal force does not act on the camshaft. Therefore, it is not necessary to make a design change such as increasing the diameter and increasing the rigidity of the camshaft, thereby avoiding an increase in the manufacturing cost of the valve timing changing device.

[0087]

As described above in detail, according to the present invention, in the protruding portion in which the insertion space is formed, the length in the circumferential direction of the rotating shafts of both the rotating bodies is not formed. It was set longer than the shape. As a result, in the protruding portion in which the insertion space is formed, the length of the seal for sealing the pressure chamber increases, and leakage of the fluid from the pressure chamber can be suppressed .

[Brief description of the drawings]

FIG. 1 is a sectional view showing an intake-side camshaft, a VVT mechanism, and the like.

FIG. 2 is a partial sectional view showing an OCV and the like.

FIG. 3 is a plan view showing an intake side, an exhaust side camshaft and the like.

FIG. 4 is a sectional view taken along line IV-IV of FIG. 1;

FIG. 5 is a sectional view showing a vane, a housing, and the like.

FIG. 6 is an enlarged sectional view showing a lock pin, a through hole, and the like.

FIG. 7 is an enlarged sectional view showing a lock pin, a through hole, and the like.

FIG. 8 is a front view showing a vane.

FIG. 9 is an enlarged sectional view showing a pressure receiving unit.

FIG. 10 is a sectional view taken along line XX of FIG. 9;

FIG. 11 is a plan view showing an intake side, an exhaust side camshaft and the like.

FIG. 12 is a sectional view showing a valve timing changing device according to a conventional technique.

FIG. 13 is a sectional view taken along the line XIII-XIII of FIG. 12;

FIG. 14 is an enlarged sectional view showing a lock pin, a through hole, and the like.

[Explanation of symbols]

12 ... intake side camshaft (camshaft), 13 ... advance side hydraulic chamber (pressure chamber), 14 ... retard side hydraulic chamber (pressure chamber), 18 ... cylinder head (constituting part of the internal combustion engine), 22: driven gear (second rotating body), 28: housing (second rotating body), 29: vane (first rotating body),
42 ... through-hole (insertion space), 43 ... lock pin (movable member), 44 ... hydraulic chamber (drive means), 45 ... first pressure oil passage (drive means), 48 ... spring (drive means), 49 ...
Locking hole (locking portion, driving means), 50: second pressure oil passage (driving means), 91: drive gear (second rotating body).

Claims (2)

(57) [Claims] 1. A plurality of projecting portions extending in a radial direction of the rotation axis formed on the first rotor of the first rotating body and the second rotating member having the same axis of rotation, before Symbol a plurality of recesses formed in the second rotary member, before SL on at least one side of the protruding portions in the circumferential direction of the I Ri before Symbol rotation axis in that each protrusion is disposed within said each recess comprising <br/> a pressure chamber which is partitioned and formed, among the cam shaft for opening and closing the valve of the crankshaft and the engine of the internal combustion engine, with one is drivingly connected to the first rotary member and the other Is drivingly connected to the second rotating body, and changes the pressure of the fluid supplied to each pressure chamber to relatively rotate the two rotating bodies, thereby changing the rotation phase of the camshaft with respect to the crankshaft, and it is possible to change the opening and closing timing of, before Symbol The movable member is disposed in the protrusion part which is formed in the insertion space, the locking by the second rotary body formed engagement portion to move the same movable member in front Symbol insertion space In the valve timing changing apparatus for an internal combustion engine capable of restricting the relative rotation of the two rotating bodies and maintaining the rotation phase of the camshaft with respect to the crankshaft at a predetermined phase, the projecting portion in which the insertion space is formed The length of the rotation axis in the circumferential direction is set longer than the length of the other protrusions in the same direction, and each of the lengths around the rotation axis is
A valve timing changing device for an internal combustion engine, wherein an inertia moment of a protruding portion is set to be equal . 2. A first rotating body having the same rotation axis,
The rotation axis formed on the first rotating body of the second rotating body
A plurality of protrusions extending in the radial direction of the second rotating body;
The plurality of recesses formed, and each of the protrusions is located in each of the recesses.
Being disposed in the circumferential direction of the rotation axis,
And a pressure chamber defined on at least one side of the projection.
Equipped with a crankshaft of an internal combustion engine and a valve of the engine
One of the camshafts for driving the opening and closing of the
The first rotating body is drivingly connected to the first rotating body, and the other is the second rotating body.
To drive and change the pressure of the fluid supplied to each pressure chamber.
Further, by rotating the two rotating bodies relatively, the
Changes the rotation phase of the camshaft with respect to the crankshaft.
It is possible to further change the opening and closing timing of the valve
In the insertion space formed in one of the projections
Movable members installed Then, the movable member is moved in the insertion space.
To be locked by the locking portion formed on the second rotating body.
By controlling the relative rotation of the two rotating bodies,
The rotation phase of the camshaft with respect to the
Apparatus for changing valve timing of internal combustion engine capable of maintaining phase
At The protrusions are arranged symmetrically with respect to the rotation axis.
At the same time, the insertion space is formed among these protrusions.
The length of the projected portion in the circumferential direction of the rotation axis is
The length is set to be longer than the length of the
A valve timing changing device for an internal combustion engine.