JP2004346780A - Variable valve timing device for internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a variable valve timing device for an internal combustion engine causing no incomplete lock releasing of a lock pin. <P>SOLUTION: (1) In the variable valve timing device 10 for the internal combustion engine, a hydraulic chamber 17 for driving the lock pin is provided in an oil passage 15 for driving a rotor vane, and downstream side parts 15h, 15e of the hydraulic chamber 17 for driving the lock pin of the oil passage 15 for driving the rotor vane are connected to the oil chamber 14 for driving the rotor vane. (2) The hydraulic chamber 17 for driving the lock pin is formed in the rotor vane 13 comprising a laminate of a plurality of pieces 13a, 13b and 13c. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a variable valve timing (VVT) device for an internal combustion engine.
[0002]
[Prior art]
Japanese Patent Laying-Open No. 10-159516 discloses a conventional variable valve timing device for an internal combustion engine.
As shown in FIGS. 6 and 7, a conventional variable valve timing device for an internal combustion engine has a housing 11 that rotates synchronously with the rotation of a crankshaft, a rotation phase of the housing 11 is variable, and the camshaft 18 is integrated. , A rotor vane driving oil chamber 14 for rotating the rotor vane 13 relative to the housing 11, a rotor vane driving oil passage 15 for supplying oil to the rotor vane driving oil chamber 14, and a rotor vane 13. A lock pin 16 for locking and unlocking relative rotation with respect to the housing 11 and a lock pin driving hydraulic chamber 17 for locking and unlocking the lock pin 16 are provided.
When the hydraulic pressure is not applied to the rotor vane driving oil passage 15, the lock pin 16 is urged by the spring 19 to enter the hole 12 of the housing 11 so that the rotor vane 13 cannot rotate relative to the housing 11. Locked. When oil pressure is applied to the rotor vane drive oil passage 15, oil pressure from the rotor vane drive oil passage 15 is applied to the lock pin 16 via the passage portion 15 a, and the lock pin 16 is pressed against the bias of the spring 19. The rotor vane 13 is unlocked so as to be rotatable relative to the housing 11 by being moved in a direction in which the rotor vane 13 is pulled out from the hole 12 of the housing 11, and the hydraulic pressure from the oil passage 15 for driving the rotor vane is supplied to the rotor vane 13 via the passage portion 15 b. The camshaft 18 fixed to the rotor vane 13 is rotated by a predetermined phase angle with respect to the housing 11 which rotates synchronously with the rotation of the crankshaft, by rotating the rotor vane 13 relative to the housing 11 and engaging the oil chamber 14. Change valve timing.
In the conventional configuration, the oil supply passage to the rotor vane drive oil chamber 14 and the oil supply passage to the lock pin drive hydraulic chamber 17 are parallel to each other, and the rotor vane drive oil chamber 14 and the lock pin drive The hydraulic pressure is applied to the hydraulic chamber 17 almost simultaneously.
[0003]
[Patent Document 1]
JP 10-159516 A
[Problems to be solved by the invention]
However, the above prior art has the following problems.
Since oil pressure is applied to the rotor vane driving oil chamber 14 and the lock pin driving hydraulic chamber 17 at substantially the same time, the rotor vane 13 may try to rotate without the lock pin 16 coming out of the hole 12 of the housing 11. In this case, the lateral force from the rotor vane 13 acts on the lock pin 16, and the lock pin 16 does not come out of the hole 12 of the housing 11, and the lock is not released, so that the valve timing cannot be changed.
SUMMARY OF THE INVENTION It is an object of the present invention to provide a variable valve timing device for an internal combustion engine in which lock release failure of a lock pin does not occur.
[0005]
[Means for Solving the Problems]
The present invention that achieves the above object is as follows.
(1) a housing that rotates synchronously with the rotation of the crankshaft;
A rotor vane having a variable rotation phase with the housing and rotating integrally with the camshaft;
A rotor vane driving oil chamber for rotating the rotor vane relative to the housing,
A rotor vane drive oil passage for supplying oil to the rotor vane drive oil chamber,
A lock pin for locking and unlocking the relative rotation of the rotor vane to the housing;
A lock pin drive hydraulic chamber for locking and unlocking the lock pin,
A variable valve timing device for an internal combustion engine comprising:
The variable valve timing of the internal combustion engine, wherein the lock pin driving hydraulic chamber is provided in the middle of the rotor vane driving oil passage, and a portion of the rotor vane driving oil passage downstream of the lock pin driving hydraulic chamber is connected to the rotor vane driving oil chamber. apparatus.
(2) The variable valve timing apparatus for an internal combustion engine according to (1), wherein the lock pin driving hydraulic chamber is formed in the rotor vane, and the rotor vane is formed of a laminated body of a plurality of pieces.
[0006]
In the variable valve timing device for an internal combustion engine of the above (1), the downstream portion of the oil passage for driving the rotor vane from the hydraulic chamber for driving the lock pin is connected to the oil chamber for driving the rotor vane. The latter oil is supplied to the rotor vane driving oil chamber through a portion of the rotor vane driving oil passage downstream of the lock pin driving hydraulic chamber. As a result, the oil moves the lock pin to the unlocked position in the lock pin drive hydraulic chamber, passes through the lock pin drive hydraulic chamber, and then moves the portion of the rotor vane drive oil passage downstream of the lock pin drive hydraulic chamber from the lock pin drive hydraulic chamber. The oil passes through the oil chamber for driving the rotor vanes to rotate the rotor vanes with respect to the housing. Therefore, since the rotor vane is rotated after the lock pin unlocks the rotor vane, the rotor vane does not apply a lateral force to the lock pin to pry the lock pin when the rotor vane is rotated. That is, it is possible to prevent a lock release failure from occurring as in the related art.
In the variable valve timing device for an internal combustion engine of the above (2), the lock pin driving hydraulic chamber is formed in the rotor vane, and the rotor vane is formed of a laminated body of a plurality of pieces. The formation of the oil passage is facilitated.
[0007]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, a variable valve timing apparatus for an internal combustion engine according to the present invention will be described with reference to FIGS. 4 and FIG. 5 correspond to those of the variable valve timing device for an internal combustion engine according to the present invention shown in FIG. 4 and FIG. 6 and FIG.
[0008]
As shown in FIGS. 1 to 5, a variable valve timing device 10 for an internal combustion engine according to the present invention includes a housing 11 that rotates synchronously with the rotation of a crankshaft; A rotor vane 13 that rotates in a rotating manner, a rotor vane driving oil chamber 14 that rotates the rotor vane 13 relatively to the housing 11, a rotor vane driving oil passage 15 that supplies oil to the rotor vane driving oil chamber 14, and a rotor vane 13. A lock pin 16 for locking and unlocking the relative rotation of the lock pin 16 with respect to the housing 11, and a lock pin driving hydraulic chamber 17 for locking and unlocking the lock pin 16.
In the present invention, the lock pin drive hydraulic chamber 17 is provided in the middle of the rotor vane drive oil passage 15, and the portions 15 h, 15 e of the rotor vane drive oil passage 15 on the downstream side of the lock pin drive hydraulic chamber 17 are provided. It is connected to a rotor vane driving oil chamber 14.
[0009]
More specifically, the housing 11 is integrally fixed to the driven gear 11a (which may be regarded as a part of the housing 11) by bolts 20, and rotation of the crankshaft is transmitted by a belt or the like, and rotation of the crankshaft is performed. And rotate synchronously.
The rotor vane 13 is fixed by a cam shaft 18 and a bolt 21. The rotor vane 13 is rotatable within the housing 11 relative to the housing 11 by a predetermined angle. When the rotor vane 13 is rotated relative to the housing 11, the relative angle between the camshaft 18 and the housing 11, which is rotated synchronously with the crankshaft, changes, and the valve timing changes. When hydraulic pressure is applied to the rotor vane driving oil chamber 14, the rotor vanes 13 rotate relative to the housing 11. Oil is supplied to the rotor vane driving oil chamber 14 via a rotor vane driving oil passage 15.
[0010]
The lock pin 16 locks and unlocks the relative rotation of the rotor vane 13 with respect to the housing 11. The lock pin 16 is movable in the lock pin axial direction, is inserted into a lock pin drive hydraulic chamber 17 formed in the rotor vane 13, and a tip end of the lock pin can protrude into the hole 12 of the housing 11. The lock pin 16 is urged by a spring 19 in a direction in which the tip end of the lock pin projects into the hole 12 of the housing 11. The lock pin 16 has an enlarged head, and when hydraulic pressure is applied to the lock pin drive hydraulic chamber 17, pressure is applied in a direction in which the tip of the lock pin comes out of the hole 12 of the housing 11. The lock pin 16 closes the oil passage 15 for driving the rotor vanes at a lock position where the tip of the lock pin projects into the hole 12 of the housing 11. The lock pin 16 opens the rotor vane drive oil passage 15 at the lock release position where the tip end of the lock pin comes out of the hole 12 of the housing 11.
[0011]
When oil pressure is not applied to the oil passage 15 for driving the rotor vane, the lock pin 16 is urged by the spring 19 so that the tip projects into the hole 12 of the housing 11, and the rotor vane 13 cannot rotate relative to the housing 11. Locked to. In this state, the rotor vane driving oil passage 15 is closed.
When hydraulic pressure is applied to the rotor vane drive oil passage 15, hydraulic pressure is applied to the lock pin drive hydraulic chamber 17, and the lock pin 16 is pressed against the urging force of the spring 19 in the opposite direction to the urging direction of the spring 19. As a result, the tip of the lock pin 16 comes out of the hole 12 of the housing 11, and the rotor vane 13 becomes rotatable relative to the housing 11 and is unlocked. In this state, the oil passage 15 for driving the rotor vanes is open and allows oil to pass through.
[0012]
In the conventional oil path, in FIGS. 6 and 7, the oil from the oil pump 22 first enters the annular passage portion 15d via the passage portion 15c of the oil passage 15 for driving the rotor vane, and passes through the annular passage portion 15d in parallel. After entering the portions 15a and 15b, the lock pin was pulled out and the rotor vane 13 was rotated at the same time.
[0013]
On the other hand, in the present invention, in FIGS. 1 to 5, the oil from the oil pump 22 is first locked from the passage portion 15c (corresponding to the passage portion 15c in FIGS. 6 and 7) of the oil passage 15 for driving the rotor vanes. After entering the hydraulic chamber 17 for driving the pin, hydraulic pressure is applied to the hydraulic chamber 17 for driving the lock pin, the lock pin 16 is moved by the hydraulic pressure against the bias of the spring 19, and the tip of the lock pin 16 is moved to the housing 11. The rotor vane 13 is released from the hole 12 so as to be rotatable relative to the housing 11 and unlocked. Simultaneously with the movement of the lock pin 16 in the direction of withdrawing from the hole 12 of the housing 11, the rotor vane drive oil passage 15 closed by the lock pin 16 (FIG. 1) opens (FIG. 2), and the rotor vane drive oil passage 15 is opened. Portions 15h and 15e downstream of the lock pin drive hydraulic chamber 17 (the passage portion 15e is an annular passage portion corresponding to the conventional annular passage portion 15d, and the passage portion 15h is formed of the lock pin drive hydraulic chamber 17 and the passage portion 15e. Is applied to each of the plurality of rotor vane driving oil chambers 14 through a passage portion that communicates with the rotor vane. When hydraulic pressure is applied to the oil chamber 14 for driving the rotor vanes, the rotor vanes 13 rotate relative to the housing 11, the camshaft 18 integrated with the rotor vanes 13 rotates, the phase angle of the cam nose changes, and the valve timing changes.
[0014]
As shown in FIG. 3, the lock pin driving hydraulic chamber 17 is formed in the rotor vane 13. Since the lock pin driving hydraulic chamber 17 and the rotor vane driving oil passage 15 are formed to be bent in the rotor vane 13, the rotor vane 13 is formed by stacking a plurality of pieces 13a, 13b, 13c in order to facilitate the formation. It is composed of
In the example of FIG. 3, an inflow hole 15 f from the passage portion 15 c of the rotor vane driving oil passage 15 is formed in the piece 13 a. A passage portion 15g communicating with the inflow hole 15f and the lock pin driving hydraulic chamber 17 is formed in the piece 13b. A passage portion 15h is formed in the piece 13c, and the passage portion 15h communicates a lock pin drive hydraulic chamber 17 and a passage portion 15e that guides hydraulic pressure to each rotor vane drive oil chamber. The passage portion 15h and the passage portion 15e constitute a portion of the rotor vane drive oil passage 15 downstream of the lock pin drive hydraulic chamber 17.
[0015]
Next, the operation of the variable valve timing apparatus for an internal combustion engine according to the present invention will be described.
In the variable valve timing device 10 for an internal combustion engine according to the present invention, the downstream portions 15h and 15e of the lock pin drive hydraulic chamber 17 of the rotor vane drive oil passage 15 are connected to the rotor vane drive oil chamber 14, so that the lock pin drive The oil that has passed through the hydraulic chamber 17 is supplied to the rotor vane driving oil chamber 14 through portions 15h and 15e downstream of the lock pin driving hydraulic chamber of the rotor vane driving oil passage 15. As a result, the oil moves the lock pin 16 to the unlocked position in the lock pin drive hydraulic chamber 17, opens the rotor vane drive oil passage 15 that has been closed by the lock pin 16, and then rotates the rotor vane drive oil passage. 15 passes through the portions 15h and 15e on the downstream side from the lock pin driving hydraulic chamber 17 to reach the rotor vane driving oil chamber 14, and rotates the rotor vane 13 with respect to the housing 11. Therefore, since the rotor vane 13 is rotated after the lock pin 16 unlocks the rotor vane 13, the rotor vane 13 does not apply a lateral force to the lock pin 16 to pry the lock pin 16 when the rotor vane 13 is rotated. Therefore, the lock release failure due to the twisting of the lock pin 16 does not occur.
[0016]
Further, since the rotor vane 13 is formed of a laminate of a plurality of pieces 13a, 13b, 13c, the passage portions 15g, 15h can be formed by forming grooves on the surface of the pieces to be laminated. The formation of the pin drive hydraulic chamber 17 and the rotor vane drive oil passages 15g and 15h is easy.
[0017]
【The invention's effect】
According to the variable valve timing device for an internal combustion engine of the first aspect, the downstream portion of the oil passage for driving the rotor vane from the hydraulic chamber for driving the lock pin is connected to the oil chamber for driving the rotor vane. The separated oil is supplied to the rotor vane driving oil chamber through a portion of the rotor vane driving oil passage downstream of the lock pin driving hydraulic chamber. As a result, the rotor vane is rotated after the lock pin unlocks the rotor vane, so that the rotor vane does not exert a lateral force on the lock pin to pry the lock pin when the rotor vane is rotated. That is, it is possible to prevent a lock release failure from occurring as in the related art.
According to the variable valve timing device for an internal combustion engine of the present invention, the lock pin driving hydraulic chamber is formed in the rotor vane and the rotor vane is formed of a laminated body of a plurality of pieces. The formation of the oil passage for use becomes easy.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a variable pin timing device for an internal combustion engine according to the present invention in a locked state, showing a lock pin and its vicinity.
FIG. 2 is a cross-sectional view of a lock pin of a variable valve timing device for an internal combustion engine according to the present invention and its vicinity in an unlocked state.
FIG. 3 is an exploded perspective view of a rotor vane of the variable valve timing device for an internal combustion engine according to the present invention.
FIG. 4 is a sectional view of a variable valve timing device for an internal combustion engine according to the present invention.
5 is a cross-sectional view of the variable valve timing device for an internal combustion engine according to the present invention (a cross section taken along line AA in FIG. 4).
FIG. 6 is a sectional view of a conventional variable valve timing device for an internal combustion engine.
FIG. 7 is a sectional view (sectional view taken along the line AA in FIG. 6) of a conventional variable valve timing device for an internal combustion engine.
[Explanation of symbols]
10 Variable valve timing device 11 Housing 11a Driven gear (part of housing 11)
12 Housing Hole 13 Rotor Vane 14 Rotor Vane Driving Oil Chamber 15 Rotor Vane Driving Oil Passage 15a, 15b, 15d Passage Portion 15c Only in Conventional Apparatus Passage Portion 15e, 15f, 15g, 15h Only in Present Apparatus and Conventional Apparatus Passage portions 15e, 15h only in the device of the present invention Passage portion 16 of the rotor vane drive oil passage downstream of the lock pin drive hydraulic chamber 16 Lock pin 17 Lock pin drive hydraulic chamber 18 Cam shaft 19 Spring 20 Bolt (housing) And driven gear)
21 bolts (fixes rotor vane and camshaft)
22 Oil pump

Claims (2)

A housing that rotates synchronously with the rotation of the crankshaft;
A rotor vane having a variable rotation phase with the housing and rotating integrally with the camshaft;
A rotor vane driving oil chamber for rotating the rotor vane relative to the housing,
A rotor vane drive oil passage for supplying oil to the rotor vane drive oil chamber,
A lock pin for locking and unlocking the relative rotation of the rotor vane to the housing;
A lock pin drive hydraulic chamber for locking and unlocking the lock pin,
A variable valve timing device for an internal combustion engine comprising:
The variable valve timing of the internal combustion engine, wherein the lock pin driving hydraulic chamber is provided in the middle of the rotor vane driving oil passage, and a portion of the rotor vane driving oil passage downstream of the lock pin driving hydraulic chamber is connected to the rotor vane driving oil chamber. apparatus. 2. The variable valve timing apparatus for an internal combustion engine according to claim 1, wherein the lock pin driving hydraulic chamber is formed in the rotor vane, and the rotor vane is formed of a laminated body of a plurality of pieces.

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