JP2004092567A - Variable valve system of engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a variable valve system of an engine, which can form oil supply passages for timing advance and timing retard while controlling upsizing of the engine. <P>SOLUTION: A hydraulic phase variable mechanism consists of a casing member connected to a camshaft driving member, a rotating member connected to a camshaft, and a timing advance chamber and a timing retard chamber that are formed between the casing member and the rotating member. Either of the oil supply passage for timing advance that communicates the timing advance chamber with an oil pressure source or the oil supply passage for timing retard that communicates the timing retard chamber with the oil pressure source is groovely formed on the connecting surface of a cylinder head 1 and a cam holder 6, and the other passage is groovely formed on the connecting surface of the cam holder 6 and a cam cap 7. As a result, since each of the oil supply passage for timing advance and the oil supply passage for timing retard is formed on the different connecting surface, increase in the number of passages formed on the same surface can be curbed. In addition, this structure can control the width of parts comprising bearings of the cam shafts 2 and 3, and the total length of the engine. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a variable valve operating device for an engine, and more particularly, to a variable valve operating device for an engine having a hydraulic phase variable mechanism.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, as a valve timing control device for this type of engine, it is known that a hydraulic phase variable mechanism is provided at one end of a camshaft to change the phase between a sprocket or a timing pulley and the camshaft.
For example, as disclosed in Japanese Patent Application Laid-Open No. 9-195805, the variable phase mechanism includes a casing integrally connected to a cam pulley at one end of a camshaft, and a cam which is fitted in the casing to form a cam. And a rotor integrally connected to the shaft. The casing is formed in a hollow cylindrical shape, and four protruding portions extending toward the center of the hollow cylinder are formed on the inner surface of the hollow cylinder. The rotor has a radially outward direction from the outer periphery of the cylindrical boss portion. Are formed. The four projecting portions formed on the casing and the four vanes formed on the rotor are alternately arranged in the circumferential direction to form eight pressure receiving chambers. Of the eight pressure receiving chambers, each vane of the rotor is provided. In contrast, the four pressure receiving chambers located on the rotation side of the camshaft are configured as retard chambers, while the four pressure receiving chambers located on the opposite side of the retard chamber are configured as advance chambers.
In such a variable phase mechanism, when the retard chamber and the hydraulic pressure source communicate with each other, the oil pressure in the retard chamber is increased, and the rotor is rotated on the opposite side to the rotation of the camshaft with respect to the casing. While the valve timing can be changed to the retard side, when the advance chamber communicates with the hydraulic pressure source, the oil pressure in the advance chamber is increased, and the rotor is rotated relative to the casing to the side where the camshaft rotates. Thus, the valve timing can be changed to the advance side.
[0003]
[Problems to be solved by the invention]
By the way, when a hydraulic phase variable mechanism is provided as in the above-described prior art, an advance oil supply passage communicating the advance chamber with the hydraulic source, and a retard oil passage communicating the retard chamber with the hydraulic source are provided. It is necessary to add an oil supply passage.
Here, the hydraulic pressure for the variable phase mechanism is normally supplied from the hydraulic pressure source to the variable phase mechanism via the bearing portion of the camshaft, but the camshaft bearing originally has a camshaft for camshaft lubrication. Since the oil supply passage for the shaft is formed, a total of three passages, an advance oil supply passage and a retard oil supply passage, are formed in parallel with the conventional camshaft oil supply passage in the bearing portion of the camshaft. Will be done.
However, simply adding an advancing oil supply passage and a retarding oil supply passage to the camshaft bearing portion in parallel requires the width of each component, such as a cam cap, that constitutes the camshaft bearing portion to be increased. Along with this, there arises a problem that the total length of the engine becomes longer and the size of the engine becomes larger.
[0004]
The present invention has been made in view of the above-described problems, and an object of the present invention is to make it possible to additionally form an advance oil supply passage and a retard oil supply passage while suppressing an increase in the size of an engine. An object of the present invention is to provide a variable valve operating device for an engine.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides the following as a solution. That is, in the first configuration of the present invention, a camshaft that drives an intake valve or an exhaust valve;
A camshaft drive member provided on one end side of the camshaft and rotating the camshaft in synchronization with rotation of a crankshaft;
A hydraulic phase variable mechanism that changes the phase between the camshaft and the camshaft drive member, and changes the opening / closing timing of the intake valve or the exhaust valve to an advanced side or a retarded side,
A casing member connected to the camshaft driving member;
A rotating member fitted into the casing member and connected to the camshaft; and a rotating member formed between the casing member and the rotating member, which opens and closes an intake valve or an exhaust valve with an increase in hydraulic pressure. An advance chamber that rotates so that the time is on the advance side,
A retard chamber formed between the casing member and the rotating member, for rotating the rotating member such that the opening / closing timing of an intake valve or an exhaust valve is retarded with an increase in hydraulic pressure. In engine variable valve gear,
The camshaft is supported between a cam holder provided on an upper portion of a cylinder head and a cam cap provided on an upper portion of the cam holder,
An advance oil supply passage communicating the advance chamber and the hydraulic power source in the variable phase mechanism and a retard oil supply passage communicating the retard chamber and the hydraulic source in the variable phase mechanism are formed in the cylinder head. One of the advancing oil supply passage and the retarding oil supply passage is formed in a groove shape on a joint surface between the cylinder head and the cam holder, and the other passage is formed between the cam holder and the cam cap. Is formed in the shape of a groove on the joint surface between them. According to the first configuration of the present invention, since the advancing oil supply passage and the retarding oil supply passage are formed in the form of grooves on different joining surfaces, an increase in the number of passages formed on the same surface is suppressed. Therefore, it is possible to suppress an increase in the width of a component constituting a bearing portion of a camshaft such as a cam cap, thereby suppressing an overall engine length.
[0006]
Further, in the second configuration of the present invention, the camshaft for lubricating the camshaft may be provided on one of a joint surface between the cylinder head and the cam holder or a joint surface between the cam holder and the cam cap. The fuel supply passage is formed in a groove shape.
According to the second configuration of the present invention, only one of the advance oil supply passage and the retard oil supply passage and the camshaft oil supply passage are formed on one joint surface. Therefore, since all the passages are suppressed from being formed on the same plane, it is possible to suppress an increase in the width of a component constituting a bearing portion of a camshaft such as a cam cap, and to suppress an overall engine length. .
[0007]
Further, in the third configuration of the present invention, the advance oil supply passage and the retard oil supply passage are formed by branching from a main oil supply passage connected to the hydraulic pressure source. A hydraulic control valve for switching a communication state between any one of the advance oil supply passage and the retard oil supply passage and the hydraulic power source is provided.
According to the third configuration of the present invention, it is possible to switch between the advance oil supply passage and the retard oil supply passage for the hydraulic pressure source by the hydraulic control valve, and to change the opening / closing timing of the intake valve or the exhaust valve.
[0008]
Further, in the fourth configuration of the present invention, the camshaft includes an intake camshaft for driving an intake valve and an exhaust camshaft for driving an exhaust valve.
Each of the camshafts is provided with the variable phase mechanism, and the hydraulic control valve is provided for each variable phase mechanism,
The advance chamber in the variable phase mechanism is located in a direction opposite to the rotation direction of the camshaft, and the retard chamber in the variable phase mechanism is located in the same rotation direction as the rotation direction of the camshaft. With
The variable phase mechanism provided in the exhaust camshaft includes an urging member that urges the rotating member so that the opening and closing timing of the exhaust valve is at the most advanced position.
Among the hydraulic control valves, the hydraulic control valve for the variable phase mechanism provided on the exhaust camshaft is arranged close to the hydraulic power source.
Normally, when the engine is stopped and the hydraulic pressure is not supplied to both the advance chamber and the retard chamber, the rotating member of the phase variable mechanism is located at the retard side with respect to the rotating member in the casing member. , The valve is opened and closed at the most retarded position.
Here, when the exhaust valve is set to the most retarded position, the closing timing of the exhaust valve is delayed, so that the intake and exhaust overlap periods are prolonged, and the internal EGR amount is increased, thereby deteriorating the engine startability. There is.
Therefore, when a variable phase mechanism is provided for the exhaust valve, an urging member such as a spring for urging the rotating member of the variable phase mechanism to the most advanced angle has been provided.
When operating the variable phase mechanism provided with the urging member, it is desirable to increase the hydraulic pressure in order to drive the rotating member against the urging force of the urging member. According to the fourth configuration of the present invention, since the hydraulic control valve for the variable phase mechanism provided with the urging member is disposed close to the hydraulic pressure source, a high hydraulic pressure against the urging force of the urging member is provided. The opening / closing timing of the intake valve or the exhaust valve can be accurately controlled by the variable phase mechanism provided with the biasing member.
[0009]
Further, in the fifth configuration of the present invention, the camshaft includes an intake camshaft for driving an intake valve and an exhaust camshaft for driving an exhaust valve, and each of the camshafts has a variable phase. Mechanism is provided,
The advance oil supply passage or the retard oil supply passage for each of the phase variable mechanisms provided in each of the camshafts is arranged on substantially the same line.
According to the fifth configuration of the present invention, the two advancing oil supply passages or the retarding oil supply passages provided for the respective camshafts are both disposed substantially on the same line, so that camshaft bearings such as cam caps are provided. It is possible to suppress an increase in the width of the components constituting the portion, and to suppress the overall length of the engine even when both the intake camshaft and the exhaust camshaft are provided with a phase variable mechanism.
[0010]
【The invention's effect】
According to the present invention, it is possible to additionally form an advance oil supply passage and a retard oil supply passage while suppressing an increase in the size of the engine.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a plan view of a cylinder head according to an embodiment of the present invention, FIG. 2 is a side view of an engine when FIG. 1 is viewed from the left side on the paper (note that a variable phase mechanism is not shown), and FIG. FIG. 4 is a plan view of a rocker arm, and FIG. 5 is a view showing a valve spring.
As shown in FIG. 1, an intake camshaft 2 and an exhaust camshaft 3 are disposed in a cylinder head 1, and one end of each of the intake camshaft 2 and the exhaust camshaft 3 is provided with a phase variable mechanism. 4 and 5 are provided.
[0012]
As shown in FIG. 2, the intake camshaft 2 and the exhaust camshaft 3 are supported between a cam holder 6 provided on the cylinder head 1 and a cam cap 7.
Reference numeral 8 denotes an oil pump provided on the cylinder block 9.
[0013]
As shown in FIG. 3, the intake camshaft 2 and the exhaust camshaft 3 are configured to open and close two intake valves 12 and two exhaust valves 13 via rocker arms 10 and 11, respectively.
As shown in FIG. 1, the intake camshaft 2 includes a low-speed cam 2a having a different lift amount and a high-speed cam 2b (a lift amount is larger than the low-speed cam 2a) for each cylinder. As shown in FIG. 4, the rocker arm 10 on the intake side also includes a low-speed rocker arm 10a for the low-speed cam 2a and a high-speed rocker arm 10b for the high-speed cam 2b.
The low-speed rocker arm 10a has a built-in lock pin 14, while the high-speed rocker arm 10b has a lock pin insertion hole 15 through which the lock pin 14 can be inserted.
The lock pin 14 is configured so that the state of insertion and non-insertion into the lock pin insertion hole 15 is controlled to be switched by a hydraulic drive device (not shown). For example, the engine speed is equal to or less than a set speed. At this time, the lock pin 14 is set in the non-insertion state into the lock pin insertion hole, and when the engine speed is equal to or higher than the set rotation speed, the lock pin 14 is switched to the insertion state into the lock pin insertion hole 15.
Thus, the low-speed cam 2a drives the low-speed rocker arm 10a by the low-speed cam 2a, and the high-speed cam 2b independently drives the high-speed rocker arm 10b. And the high-speed rocker arm 10b are simultaneously driven.
At this time, as shown in FIG. 4, the load input point W from the high-speed cam 2b to the high-speed rocker arm 10b is set to be offset from the center L between the intake valves 12 by a predetermined amount toward the high-speed rocker arm 10b. This is because the low-speed rocker arm 10a is smaller than the high-speed rocker arm 10b, and the center of gravity is shifted toward the high-speed rocker arm 10b from the intake valve center L. When the low-speed rocker arm 10a and the high-speed rocker arm 10b are simultaneously driven by the high-speed cam 10b during high rotation, the low-speed rocker arm 10a and the high-speed rocker arm 10b are evenly balanced by matching the center of gravity with the high-speed cam 10b. Can be driven by
[0014]
Also, as shown in FIGS. 3 and 5, the valve seat 16 is configured such that its seating surface has a large diameter, and the valve spring 17 has a large diameter only in a part near the seating surface of the valve seat 16. Have been.
As a result, even when the rigidity of the valve seat 16 is reduced due to weight reduction, a large contact area of the valve spring 17 with the valve seat 16 can be ensured, and the surface pressure can be reduced. And reliability can be ensured.
[0015]
Next, details of the phase variable mechanisms 4 and 5 will be described.
6 is a sectional view of the phase variable mechanism 4, FIG. 7 is a sectional view taken along line BB of FIG. 6, and FIG. 8 is a sectional view taken along line CC of FIG.
Since the phase variable mechanisms 4 and 5 have the same structure except for a spring member P as an urging means described later, the phase variable mechanism 4 on the intake side will be described below.
As shown in FIGS. 6, 7, and 8, the variable phase mechanism 4 includes a casing 18 that is hollow and has a plurality of protrusions 18a on the inner surface, and a lid member 19 of the casing 18. And the lid member 19 are fixed to the cam pulley 21 by a plurality of bolts 20.
[0016]
The variable phase mechanism 4 also has a rotor 24 as a rotating member fixed to the intake camshaft 2 by bolts 23 via washers 22. The rotor 24 is provided with an outer periphery of a cylindrical boss 24a. Four engagement portions 24b extending in the radial direction are provided.
The engaging portions 24b are alternately arranged in the circumferential direction with the projecting portions 18a to form eight hydraulic chambers 25. Of these, eight hydraulic chambers 25 are formed with respect to each of the engaging portions 24b in the rotation direction A of the intake camshaft 2. Each of the four hydraulic chambers positioned is configured as a retard chamber 25a, and each of the four hydraulic chambers positioned in the anti-rotation direction B of the intake camshaft with respect to each engagement portion 24b is configured as an advance chamber 25b. I have.
The rotor 24 rotates relative to the cam pulley 21, the casing 18, and the cover member 19 within a predetermined range (the range shown in FIGS. 7 and 8) until the protrusion 21b and the engagement portion 24b come into contact with each other. It is possible to change the phase angle of the intake camshaft 2 with respect to the cam pulley 21, in other words, the phase angle of the intake camshaft 2 with respect to the crankshaft, thereby changing the opening / closing timing of the intake valve 12. I have.
For example, when hydraulic pressure is supplied to the retard chamber 25a, the rotor 24 is rotated in the direction B opposite to the rotation direction A of the intake camshaft 2 until the engagement portion 24b engages with the protrusion 18a. It is the most retarded position indicated by the symbol X in the middle of 3, 4. When hydraulic pressure is supplied to the advance chamber 25b, the rotor 24 is rotated in the same direction as the rotation direction A of the intake camshaft 2 until the engagement portion 24b engages with the protrusion 18a. 4 is the most advanced position indicated by the symbol X '.
[0017]
Next, the difference between the intake-side variable phase mechanism 4 and the exhaust-side variable phase mechanism 5 will be described.
As shown in FIG. 1, the variable phase mechanism 5 on the exhaust side is provided with a spring member P as urging means. The spring member P is fixed across the casing 18 and the rotor 24. Forcibly resetting the position of the rotor 24 when the engine stops and no oil pressure is supplied to both the retard chamber 25a and the advance chamber 25b. This is for biasing to the advanced position X. This is for suppressing the deterioration of the startability due to the exhaust valve 13 being at the most retarded position when the engine is stopped, the intake and exhaust overlap periods being increased, and the internal EGR being increased.
[0018]
Next, the structure of the retard oil supply passage and the advance oil supply passage for the retard chamber 25a and the advance chamber 25b will be described with reference to FIGS.
FIG. 9 is a schematic view schematically showing a retarding oil supply passage and an advance oiling passage, FIG. 10 is a plan view of the cam holder 6 as viewed from below, and FIG. 11 is a plan view of the cam cap 7 as viewed from below. FIG.
As shown in FIGS. 2 and 9, the oil pressure from the oil pump 8 is supplied to the oil pressure control valve 27 of the variable phase mechanism 5 for exhaust after passing through the main oil supply passage 26.
The hydraulic pressure supplied to the hydraulic control valve 27 is configured to be switched and supplied to the retard chamber 25a and the advance chamber 25b, respectively.
First, when the hydraulic pressure control valve 27 is switched to supply hydraulic pressure to the retard chamber 25a, a first retard oil supply passage 28 for exhaust formed in the cylinder head 1, the cylinder head 1 and the cam holder shown in FIG. 6, a groove-shaped exhaust second retard oil supply passage 29 formed on the joint surface with the cam holder 6 (the lower surface of the cam holder 6), and an exhaust third retard oil extending from the exhaust second retard oil supply passage 29 to the exhaust camshaft 3. Hydraulic pressure is applied to the retard chamber 25a through the oil supply passage 30 and a groove-shaped fourth exhaust retard oil supply passage 31 for exhaust formed in the joint surface (the lower surface of the cam cap 7) of the cam holder 6 and the cam cap 7 shown in FIG. Supplied. When the hydraulic control valve 27 is switched to supply hydraulic pressure to the advance chamber 25b, the first advance oil supply passage 32 for exhaust formed in the cylinder head 1, the cylinder head 1 and the cam holder shown in FIG. 6, a groove-shaped exhaust second advanced oil supply passage 33 formed on the joint surface with the cam holder 6 (the lower surface of the cam holder 6), and an exhaust third advanced angle extended from the exhaust second advanced oil supply passage 33 to the exhaust camshaft 3. Oil pressure is supplied to the advance chamber 25b via the oil supply passage 34.
The hydraulic control valve 35 of the intake variable phase mechanism 4 is disposed in the main oil supply passage 26 downstream of the hydraulic control valve 27 of the variable exhaust phase mechanism 5.
When the hydraulic control valve 35 is switched to supply the hydraulic pressure to the retard chamber 25a,
A first intake retarding oil supply passage 36 formed in the cylinder head 1, a groove-shaped second intake retardation formed on a joint surface (the lower surface of the cam cap 7) between the cam holder 6 and the cam cap 7 shown in FIG. 11. Oil pressure is supplied to the retard chamber 25a via the oil supply passage 37. When the hydraulic control valve 35 is switched to supply hydraulic pressure to the advance chamber 25b, the first advance oil supply passage 38 for intake formed in the cylinder head 1, the cylinder head 1 and the cam holder shown in FIG. 6, a groove-shaped intake second advanced oil supply passage 39 formed on the joint surface with the cam holder 6 (the lower surface of the cam holder 6), and an intake third advanced angle extended from the intake second advanced oil supply passage 39 to the intake camshaft 2. Hydraulic pressure is supplied to the advance chamber 25b through the oil supply passage 40.
The main oil supply passage 26 is formed so as to penetrate to the joint surface between the cam holder 6 and the cam cap 7, and the main oil supply passage 26 is, as shown in FIG. In order to supply the lubricating oil to the camshaft, it is branched to the camshaft passages 26a and 26b.
[0019]
As shown in FIG. 11, the exhaust fourth retard oil supply passage 31 and the intake second retard oil supply passage 37 extend from substantially near the center of the cam holder 6 in directions opposite to each other. The retard oil supply passage 31 and the intake second retard oil supply passage 37 are arranged substantially on the same line, and the camshaft oil supply passages 26a, 26b are also arranged on the same line, so that the cam holder 6 and the cam cap 7 are joined. The surface is configured such that substantially two oil supply passages are formed in parallel.
[0020]
As described above, according to the present embodiment, the second advance angle oil supply passage 33 for exhaust and the second advance angle oil supply passage 39 for intake constitute a part of the advance angle oil supply passage, respectively. The fourth exhaust retarding oil supply passage 31 for exhaust and the second retarding oil supply passage 37 for intake which constitute a part of the retarding oil supply passage are joined to the cam holder 6 and the cam cap 7, respectively. Since a part of the advancing oil supply passage and a part of the retarding oil supply passage are formed on different joining surfaces, the number of passages formed on the same surface increases. Therefore, the width of the cam holder 6 and the cam cap 7 can be prevented from becoming longer, and the overall length of the engine can be reduced.
Further, on the joint surface between the cam holder 6 and the cam cap 7, a fourth exhaust retarding oil supply passage 31 for exhaust and a second retarding oil supply passage 37 for intake extend from near the center of the cam holder 6 in directions opposite to each other, The two passages 31, 37 are arranged so as to be located substantially on the same line, and the camshaft oil supply passages 26a, 26b are also arranged so as to be located substantially on the same line. The width of the cam holder 6 only needs to be ensured, and even if the intake camshaft 2 and the exhaust camshaft 3 are both provided with the phase variable mechanisms 4, 5, the width of the cam holder 6 becomes long. And the overall length of the engine can be reduced.
Further, since the hydraulic control valve 27 of the variable phase mechanism for exhaust 5 is disposed close to the oil pump 8 as a hydraulic source, a high hydraulic pressure can be supplied to the variable phase mechanism for exhaust 5 and the spring The valve timing can be accurately changed by the exhaust phase variable mechanism 5 by the high oil pressure against the urging force of the member P.
[0021]
In this embodiment, an example in which a part of the retarding oil supply passage is formed on the joint surface between the cam holder 6 and the cam cap 7 and a part of the advance oil supply passage is formed on the joint surface between the cam holder 6 and the cylinder head 1. However, conversely, a part of the retarding oil supply passage is formed on the joint surface between the cam holder 6 and the cylinder head 1 and a part of the advance oil supply passage is formed on the joint surface between the cam holder 6 and the cam cap 7. It may be.
Further, in this embodiment, a part of the retard passage formed on the joint surface between the cam holder 6 and the cam cap 7 is formed on the lower surface of the cam cap 7 and on the advance surface formed on the joint surface between the cam holder 6 and the cylinder head 1. An example in which a part of the passage is formed on the lower surface of the cam holder 6 has been shown. May be formed.
Further, in the present embodiment, an example in which the variable phase mechanism is provided in both the intake camshaft 2 and the exhaust camshaft 3 has been described, but the present invention may be applied to an engine having only one of them.
[Brief description of the drawings]
FIG. 1 is a plan view of a cylinder head according to an embodiment.
FIG. 2 is a side view of the engine according to the embodiment.
FIG. 3 is a sectional view taken along line AA of FIG. 2;
FIG. 4 is a plan view of a rocker arm.
FIG. 5 is a view showing a valve spring.
FIG. 6 is a cross-sectional view of the variable phase mechanism 4.
FIG. 7 is a sectional view taken along line BB of FIG. 6;
FIG. 8 is a sectional view taken along the line CC of FIG. 6;
FIG. 9 is a schematic view schematically showing a retard angle oil supply passage and an advance angle oil supply passage.
FIG. 10 is a plan view of the cam holder 6 as viewed from a lower surface side.
FIG. 11 is a plan view of the cam cap 7 as viewed from below.
[Explanation of symbols]
1: Cylinder head 2: Intake camshaft 3: Exhaust camshaft 4, 5: Variable phase mechanism 6: Cam holder 7: Cam cap 8: Oil pump (oil pressure source)
12: intake valve 13: exhaust valve 18: casing (casing member)
21: Cam pulley (cam shaft drive member)
24: Rotor (rotating member)
25a: retard chamber 25b: advance chambers 26a, 26b: camshaft oil supply passages 27, 35: hydraulic control valve 28: exhaust first retard oil supply passage (retard oil supply passage)
29: Exhaust second retard lubrication passage (retard lubrication passage)
30: Exhaust third retard lubrication passage (retard lubrication passage)
31: Exhaust fourth retard lubrication passage (retard lubrication passage)
32: First advance oil supply passage for exhaust (advance oil supply passage)
33: Second advance oil supply passage for exhaust (advance oil supply passage)
34: Exhaust third advance oil supply passage (advance oil supply passage)
36: Intake first retard lubrication passage (retard lubrication passage)
37: second intake retard oil supply passage (retard oil supply passage)
38: First advance oil supply passage for intake (advance oil supply passage)
39: intake second advance oil supply passage (advance oil supply passage)
40: Third advance oil supply passage for intake (advance oil supply passage)
P: Spring member (biasing member)

Claims (5)

A camshaft that drives an intake or exhaust valve,
A camshaft drive member provided on one end side of the camshaft and rotating the camshaft in synchronization with rotation of a crankshaft;
A hydraulic phase variable mechanism that changes the phase between the camshaft and the camshaft drive member, and changes the opening / closing timing of the intake valve or the exhaust valve to an advanced side or a retarded side,
A casing member connected to the camshaft drive member and integrally rotating with the camshaft drive member;
A rotating member fitted into the casing member and connected to the camshaft to rotate integrally with the camshaft;
An advance chamber formed between the casing member and the rotating member, and rotating the rotating member such that the opening / closing timing of an intake valve or an exhaust valve is advanced with an increase in hydraulic pressure,
A retard chamber formed between the casing member and the rotating member, for rotating the rotating member such that the opening / closing timing of an intake valve or an exhaust valve is retarded with an increase in hydraulic pressure. In engine variable valve gear,
The camshaft is supported between a cam holder provided on an upper portion of a cylinder head and a cam cap provided on an upper portion of the cam holder,
The cylinder head is formed with an advance oil supply passage communicating the advance chamber and the hydraulic pressure source in the variable phase mechanism, and a retard oil supply passage communicating the retard chamber and the hydraulic source in the variable phase mechanism. A part of one of the advancing oil supply passage and the retarding oil supply passage is formed in a groove shape on a joint surface between the cylinder head and the cam holder, and a part of the other passage is formed. A variable valve gear for an engine, wherein the groove is formed on a joint surface between the cam holder and the cam cap. A camshaft lubrication passage for lubricating the camshaft is formed in a groove on one of the joining surface between the cylinder head and the cam holder or the joining surface between the cam holder and the cam cap. 2. The variable valve operating device for an engine according to claim 1, wherein: The advance oil supply passage and the retard oil supply passage are branched from a main oil supply passage connected to the hydraulic pressure source, and the main oil supply passage includes the advance oil supply passage and the retard oil supply passage. 3. The variable valve train for an engine according to claim 1, further comprising a hydraulic control valve for switching a communication state between any one of the passages and the hydraulic power source. The camshaft includes an intake camshaft for driving an intake valve, and an exhaust camshaft for driving an exhaust valve,
Each of the camshafts is provided with the variable phase mechanism, and the hydraulic control valve is provided for each variable phase mechanism,
The advance chamber in the variable phase mechanism is located in a direction opposite to the rotation direction of the camshaft, and the retard chamber in the variable phase mechanism is located in the same rotation direction as the rotation direction of the camshaft. With
The variable phase mechanism provided in the exhaust camshaft includes an urging member that urges the rotating member so that the opening and closing timing of the exhaust valve is at the most advanced position.
4. The variable operation of the engine according to claim 3, wherein, among the hydraulic control valves, the hydraulic control valve for the variable phase mechanism provided on the exhaust camshaft is arranged close to the hydraulic power source. Valve device. The camshaft includes an intake camshaft for driving an intake valve, and an exhaust camshaft for driving an exhaust valve, and each of the camshafts includes the phase variable member,
The engine according to any one of claims 1 to 4, wherein an advance oil supply passage or a retard oil supply passage for each of the phase variable mechanisms provided on each of the camshafts is arranged substantially on the same line. Variable valve gear.

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