JPH03115712A - Valve moving device of engine - Google Patents

Abstract

PURPOSE:To improve durability of a hydraulic lash adjuster in a valve moving device of an engine, in which three valves are opened/closed by a single cam shaft through swing arms, by devising arrangement position and oiling structure of the hydraulic lash adjuster for receiving one ends of the swing arms of each of the valves. CONSTITUTION:Openings on the side of a combustion chamber of three independent intake ports 11 to 13 at each cylinder are provided in fore and aft direction of an engine side by side for the ports 11 and 13 on both sides and at the position close to a cylinder bore center for the center port 12 and are opened/closed by intake valves 31 to 33 respectively. The intake valve 31 to 33 are opened/ closed by rotation of three intake cams 93 provided at a cam shaft 91 through swing arms 81 to 83 whose one ends are supported by hydraulic lash adjusters (Adj) 71 to 73. In this case, the center Adj 72 is arranged on the delay side of the cam shaft rotation direction, while Adj 71 and 73 on both sides are arranged on the advance side. Also, an oil passage is formed so that oiling is done first for the center Adj 72 and then, for Adj 71 and 73 on both sides.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a valve operating system for an engine that is provided with three intake valves or three exhaust valves.

(Prior art) Conventionally, as this type of engine, for example, Japanese Patent Application Laid-Open No. 62-7
As disclosed in Japanese Patent No. 8453, it is known that each cylinder is provided with three intake valves and two exhaust valves to obtain high intake/exhaust efficiency. In this engine, three intake valves are provided so as to be inclined toward the cylinder bore side toward the end of the valve shaft, and two exhaust valves are provided to be inclined toward the other side of the cylinder bore toward the end of the valve shaft. The lower surfaces of the intake and exhaust valve heads are arranged in a chevron shape, thereby forming a vent roof-shaped combustion chamber with high combustion efficiency. In this engine, the intake valve is driven by a camshaft exclusively for intake via a rocker arm, and the exhaust valve is driven by a camshaft exclusively for exhaust via a rocker arm.

That is, rocker shafts dedicated to intake and exhaust are provided extending in the cylinder row direction on the side far from the center of the cylinder bore relative to the intake/exhaust valves, one end of the rocker arm is pivotally supported on the rocker shaft, and the other end of the rocker arm is pivoted to the rocker shaft. is placed on the end of the valve shaft of the intake/exhaust valve, and the cam part of the camshaft arranged above the rocker arm is brought into contact with the middle part of the rocker arm from above, and as the camshaft rotates, the rocker arm is made to swing around the rocker shaft to move the intake and exhaust valves up and down.

(Problem to be Solved by the Invention) In such an engine, a swing arm is supported by a hydraulic lash adjuster instead of a rocker arm, and this swing arm is used to operate the intake and exhaust valves without valve lash. It is conceivable to drive it. That is, a hydraulic lash adjuster is provided on the side of the intake/exhaust valve, one end of the swing arm is placed on the support of the hydraulic lash adjuster, and the other end of the swing arm is placed on the end of the valve shaft of the intake/exhaust valve. The cam part of the camshaft disposed above the swing arm is brought into contact with the middle part of the swing arm from above, and as the camshaft rotates, the swing arm swings around the support part of the hydraulic lash adjuster. It moves the intake and exhaust valves up and down.

In that case, in each cylinder, an intake valve would be provided on the cylinder bore side, so the engine would become larger unless the layout of the swing arm and hydraulic lash adjuster was devised.

Generally, a hydraulic lash adjuster includes a cylindrical casing with a bottom and an inner sleeve that is slidably inserted into the casing, and the head of the inner sleeve has a pivot for receiving the swing arm, etc. The structure includes a support section. Then, high hydraulic pressure is supplied to the hydraulic chamber formed between the casing and the inner sleeve to urge the inner sleeve in the direction of exiting from the casing, and the acting force between the swing arm and the support section, that is, the supporting force By maintaining a high clearance between the swing arm and the camshaft and the suction between the swing arm and
The clearance between the exhaust valve and the exhaust valve is set to zero.

In a hydraulic lash adjuster with this type of structure, the inner sleeve repeatedly moves back and forth against the casing, so if a large supporting force is applied, the sliding surface of the inner sleeve will wear unevenly, causing problems such as oil leakage from the hydraulic chamber. This will cause damage to the durability and reliability of the hydraulic lash adjuster. By the way, if we consider the transmission of force around the swing arm in Fig. 9, the contact force of cam C acts on swing arm A. This force is divided into two parts and acts on the valve shaft end of the valve V and the support part of the hydraulic lash adjuster L. The force acting on this hydraulic lash adjuster support portion becomes the above-mentioned supporting force F. In that case, the lever ratio R indicates how many times the stroke amount of the valve V moves relative to the lift amount of the cam C (specifically, the contact point to the hydraulic lash adjuster support part in the swing arm A and the valve V). Using the value obtained by dividing the distance from the contact point to the shaft end by the distance 9 between the contact point to the hydraulic lash adjuster support part on swing arm A and the contact point to cam C, R-L/, Q) Considering this, if the contact force of the cam C is the same, the supporting force F increases as the lever ratio R increases.

Therefore, when the rotation direction of the cam C is set in the direction of the solid line arrow in FIG. When compared with the case where only the hydraulic lash adjuster is installed on the forward side in the rotational direction of the camshaft, there is a difference in the fluctuation of the lever ratio R, as shown in Figure 10. Adjuster L
When is placed on the delayed side of the camshaft rotation direction (solid line)
If the camshaft is installed on the advancing side of the rotational direction (
In the case of the broken line), the maximum value of the support no.

The present invention has been made with attention to these points,
The purpose of this is to provide a cylinder with three intake or exhaust valves, and when these valves are driven using a swing arm and hydraulic lash adjuster, the layout of each component can be devised to make the engine more compact. However, due to its layout, the lever ratio is large, so oil is supplied preferentially to the hydraulic lash adjuster that supports the swing arm, improving the durability and reliability of the hydraulic lash adjuster. be.

(Means for Solving the Problem) In order to achieve the above object, in the present invention, the swing arm and the hydraulic lash adjuster are arranged in a staggered manner when viewed in the axial direction of the camshaft, and the lever ratio of the swing arm is increased. The hydraulic pressure is applied stably to the hydraulic lash adjuster in the central valve.

Specifically, the solution taken by the present invention is based on an engine valve train having three intake or exhaust valves for each cylinder driven by a single camshaft via a swing arm. do. In contrast, among the three valves, the central valve and the two valves on both sides are disposed offset in the direction orthogonal to the camshaft. In addition, a hydraulic lash adjuster that has a support part that receives the swing arm of the central valve is installed on the lag side in the rotational direction of the camshaft, and a hydraulic lash adjuster that has a support part that receives the swing arms of both valves is installed on the camshaft rotation direction. Place it on the forward direction side. A dedicated oil passage is provided to first supply the oil in the main oil passage to the hydraulic lash adjuster of the central valve, and then to the hydraulic lash adjusters of the valves on both sides.

(Function) With the above configuration, in the present invention, the central valve and the two valves on both sides are arranged to be shifted from each other in the direction orthogonal to the camshaft, and the hydraulic lash adjuster and swing arm of the central valve are connected to the two valves on both sides. Since the hydraulic lash adjusters and swing arms of the valves are arranged in a staggered manner on both sides of the camshaft, the engine can be made compact.

In this case, since the hydraulic lash adjusters of both valves are arranged on the advancing side of the shaft in the rotating direction, the lever ratio of the swing arm is reduced and the supporting force of the hydraulic lash adjusters is suppressed.

On the other hand, the hydraulic lash adjuster of the central valve is placed on the lag side in the rotational direction of the camshaft, increasing its supporting force. Since the oil is supplied before the lash adjuster, the oil pressure acts stably and the inner sleeve reciprocates smoothly.

Therefore, the durability and reliability of the hydraulic run-your-adjuster are improved.

(Example) Embodiments of the present invention will be described below based on the drawings.

4 to 7 show an in-line three-cylinder engine with an intake pressure valve and two exhaust valves, which is equipped with a valve train according to an embodiment of the present invention. Although these figures show only one cylinder as a representative, the other cylinders have the same configuration.

In these figures, 1 is a cylinder block, 2 is a cylinder head disposed on the cylinder block 1, and 3 is a cam carrier member disposed on the cylinder head 2.

A cylinder 5 is formed in the cylinder block 1, and a piston 6 is slidably fitted into the cylinder 5. The cylinder head 2 also has two inclined walls 7a, 7.
A vent-roof-shaped combustion chamber 7 is formed having a diameter b.

On the left side of the cylinder bore of the cylinder head 2, there are three independent intake ports 1.1 and 12 that lead fresh air to the cylinder 5.
13 are provided. This independent intake port 12-13
has one end open to the left inclined wall 7a of the combustion chamber 7,
The other end is provided to open on the left side wall of the cylinder head. The combustion chamber side openings of the independent intake ports 11, 13 on both sides are lined up in the engine longitudinal direction (vertical direction in FIG. 7), and are provided at a position closer to the center of the cylinder bore than the central independent intake port 12. These three independent intake boats 11 to 13 are assembled into one intake boat 10 on the left side wall of the cylinder head.

Furthermore, on the right side of the cylinder bore of the cylinder head 2, there are two independent exhaust boats 21.
22 are provided. This independent exhaust port h21, 22
has one end open to the right inclined wall 7b of the combustion chamber 7,
The other end is provided so as to open on the right side wall of the cylinder head. The combustion chamber side openings of these two independent exhaust ports 21 and 22 are aligned in the engine longitudinal direction. Furthermore, the two exhaust ports 21 and 22 are combined into one exhaust port 20 on the right side wall of the cylinder head.

The cylinder head 2 includes independent intake boats 11 to 13.
Three intake valves 31. which respectively open and close the combustion chamber side openings.
32.33 are provided. Each intake valve 31 to 33 is
It has an umbrella-shaped valve head disposed in the opening, and a valve shaft extending upward from the valve head, and is slidably fitted into the cylinder head 2 at the valve shaft. hand,
It can be moved up and down. At the ends of the valve shafts of these intake valves 31 to 33 are disk-shaped spring seats 51, 52, 53.
are installed respectively, and these spring seats 51~.
A valve spring 61 is installed between the valve spring 53 and the cylinder head 2.
, 62 and 63 are compressed, and their spring force urges each intake valve 31 to 33 upward, that is, in the valve closing direction.

These three intake valves 31 to 33 are provided so that the cylinder bores are inclined to the left side toward the end of the valve shaft, and the valve shafts are parallel to each other.

The cylinder head 2 also has an independent exhaust port 21.2.
Two exhaust valves 41 that open and close the combustion chamber side openings of No. 2, respectively.
．． ．． 42 are provided. These exhaust valves 41, 42 have the same structure as the intake valves 31 to 33, and are provided so as to be movable up and down, and are biased in the valve closing direction by being provided with spring seats 54, 55 and valve springs 64, 65.

These two exhaust valves 41 and 42 are provided so that they are inclined to the right side of the cylinder bore toward the end of the valve shaft, and the valve shafts are parallel to each other.

Next, a driving mechanism for the intake/exhaust valves 31 to 33, 41, and 42 will be explained. On the left and right sides of the cam carrier member 3, camshafts 91 and 92 exclusively for intake and exclusively for exhaust, respectively, extending in the longitudinal direction of the engine are arranged. These two camshafts 91 and 92 are driven by an engine output shaft (not shown), and the intake camshaft 91 is driven clockwise in FIG.
2 rotates counterclockwise in the same figure. Further, the intake camshaft 91 is integrally formed with three intake cams 93 corresponding to each of the intake valves 31 to 33, and the exhaust only camshaft 92 is integrally formed with two exhaust cams corresponding to each exhaust valve 41, 42. 94 are integrally formed.

From the above, among the three intake valves 31 to 33, the central intake valve 32 and the two intake valves 31°33 on both sides are arranged offset in the direction orthogonal to the camshaft. .

The intake valves 31 to 33 are driven by an intake camshaft 91 via swing arms 81, 82, 83. That is, the cylinder head 2 is provided with known hydraulic lash adjusters 71, 72, and 73.

The hydraulic lash adjusters 71 to 73 are provided with support portions. And the above swing arms 81 to 8
3, one end is connected to the hydraulic lash adjusters 71 to 73.
The intake valves 31 to 33 are provided so as to rest on the support portion thereof, and the other end thereof rests on the valve shaft ends of the intake valves 31 to 33. Further, a roller having a rotating shaft in the engine longitudinal direction is provided in the middle of the swing arms 81 to 83, and this roller is connected to the intake cam 9.
3 are in contact with each other. Therefore, when the intake camshaft 91 rotates, the rollers move up and down in accordance with the lift amount of the intake cam 93, which causes the swing arms 81 to 83 to swing up and down around the end on the hydraulic lash adjuster side. move. For this purpose, the ends of the swing arms 81 to 83 on the valve shaft end side swing up and down according to the lever ratio, and the intake valves 31 to 33
is designed to open and close.

In addition, the exhaust valves 41 and 42 are also connected to the exhaust dedicated camshaft 92.
is driven via swing arms 84 and 85.

This drive mechanism is configured to include hydraulic lash adjusters 74 and 75 that support swing arms 84 and 85 as in the case of the intake valves 31 to 33, and when the exhaust camshaft 92 rotates, the exhaust cam The rollers of the swing arms 8485 move up and down according to the lift amount of the swing arms 84, 85, which causes the swing arms 84 and 85 to swing up and down around the end on the hydraulic lash adjuster side, and the valves of the swing arms 84 and 85 move up and down. The end on the shaft end side swings up and down depending on the lever ratio, and the exhaust valve 41. ．． 42 opens and closes.

Here, the structure of the hydraulic lash adjusters 71 to 73 will be explained with reference to FIG. 8. In the figure, 111 is a cylindrical casing with a bottom, 112 is an inner sleeve slidably inserted into the casing, and a hydraulic chamber 114 is formed between the casing 11 and the inner sleeve 1]2. has been done. Furthermore, a pivot 113 is provided at the upper end of the inner sleeve 112 as a support portion for receiving the ends of the swing arms 81 to 83. The casing 111 and the inner sleeve 112 are provided with an oil passage 115 which has one end communicating with the hydraulic chamber 114 and the other end communicating with an oil inlet 116 provided on the outer wall of the casing. A check valve 118 for maintaining the hydraulic pressure in the hydraulic chamber 114 at a high pressure is provided at the end of the oil passage 115 on the hydraulic chamber side. In addition, inner sleeve 11
2 is provided with an oil discharge passage 117 that communicates with the oil passage 115 at one end and opens at the center of the pivot 113 at the other end to relieve oil.

To explain the operation of the hydraulic lash adjusters 71 to 73, when there is lash in the valve train and the support force that the pivot 113 receives from the swing arms 81 to 83 is low, the hydraulic pressure in the hydraulic chamber 114 is low, so the check valve 118 opens. For this purpose, oil is supplied to the hydraulic chamber 114 from the oil inlet 116 through the oil passage 115, and
14 causes the inner sleeve 112 to come out of the casing]11. This provides a clearance between the swing arms 81 to 83 and the intake camshaft 9] and a clearance between the swing arms 81 to 83 and the intake valves 31 to 3.
The clearance between 3 and 3 becomes zero. In this case, the supporting force that the pivot 113 receives from the swing arms 81 to 83 increases, and the hydraulic pressure in the hydraulic chamber 114 increases, so that the check valve 118 closes. As a result, the position of the inner sleeve 112 relative to the casing is fixed, and the swing arms 81 to 83 are no longer supported by the pivot 113.

Next, the arrangement of the hydraulic lash adjusters 71 to 75 will be explained. First, in the case of the intake side, the hydraulic lash adjuster 72 of the central intake valve 32
33 on the side closer to the center of the cylinder bore. That is, this hydraulic lash adjuster 72 is arranged on the lag side in the rotational direction of the camshaft. This hydraulic lash adjuster 72 is provided to be inclined at a predetermined angle to the left toward the pivot 113. That is, the hydraulic lash adjuster 72 is provided so that its central axis coincides with the supporting force received from the swing arm 82. Further, the hydraulic lash adjusters 71 and 73 of the intake valves 31 and 33 on both sides are provided on the side far from the center of the cylinder bore with respect to the intake valves 31 to 33. That is, the hydraulic lash adjusters 71, 73 are arranged on the advancing side of the camshaft rotation direction. In other words, the hydraulic lash adjusters 71 to 73 on the intake side are arranged in a staggered manner across the intake valves 31 to 33 when viewed from the front and back direction of the engine. The cylinder head 2 has a central intake valve 3.
2 oil inlet port 116 of hydraulic lash adjuster 72
The oil supply passage 121 that communicates with the intake valves 31 on both sides
．． An oil supply passage 122 communicating with the oil inlet 116 of the 33 hydraulic lash adjusters 71 and 73 is provided.

In addition, in the case of the exhaust side, the hydraulic lash adjusters 74.75 of the two exhaust valves 41.42 are
2, it is provided on the side far from the center of the cylinder bore. That is, this hydraulic lash adjuster 74.7
5 is disposed on the advancing side of the camshaft in the rotational direction. The cylinder head 2 is provided with an oil supply passage 123 that communicates with the oil inlets 116 of the two hydraulic lash adjusters 7475.

Next, a structure for supplying oil to the oil supply passages 121 to 123 will be explained based on FIGS. 1 to 3. In these figures, reference numeral 131 denotes a first passage, and one end of the first passage 131 is connected to the central part in the longitudinal direction of a main oil passage (not shown) that extends through the cylinder block 1 in the longitudinal direction. As shown in FIG. 1, the other end has a passage portion 131a that passes upward through the cylinder block 1 and reaches the inside of the cylinder head 2, and a passage portion 131a that extends inside the cylinder head 2 toward the rear (to the right in FIG. 2) and leads to the cylinder. It consists of a passage portion 131b leading to the rear portion, and a passage portion 131C extending upwardly through the cylinder head 2 at the rear portion of the cylinder head and reaching into the cam carrier member 3.

A second passage 132 is connected to the first passage 131 . One end of the second passage 132 is connected to the first passage 131 in the cam carrier member 3, and the other end extends diagonally forward to the right as shown in FIG. a passage portion 132a extending from the center of the cam carrier member 3 in the left-right direction
2b. A bearing oil supply passage is connected to each left and right end of this passage portion 132b, and the bearing oil supply passage is connected to a portion of the bearing collar of the camshaft 91, 92 (
(not shown).

A third passage 133 is connected to the second passage 132. The third passage 133 has one end connected to the passage portion 132b of the second passage 132 in the cam carrier member 3, and the other end passes through the cam carrier member 3 downward to reach the inside of the cylinder head 2, and is connected to the oil supply. It is connected to the passage 121. A left branch passage 134 and a right branch passage 135 are connected to the third passage 133, and the left branch passage 134 and the right branch passage 135 are connected to the oil supply passages 122 and 123, respectively.

Therefore, high-pressure oil pressurized by the engine's oil pump (not shown) and supplied to the main oil passage passes through the first passage 131 and the second passage 132 to the third passage 133.
supplied to The oil supplied to this third passage 133 is first supplied to the oil supply passage 121,
Oil is supplied from this oil supply passage 121 to the hydraulic pressure adjuster 72 of the central intake valve 32. On the other hand, the third
Of the oil supplied to the passage 133, the remaining oil is supplied to the oil supply passages 122, 123 via the left branch passage 134 and the right branch passage 135, and from the oil supply passages 122, 123 to the intake valves 31 on both sides. .33 hydraulic lash adjuster 7173 and exhaust valve 41.42 hydraulic lash adjuster 74.75. Further, a portion of the oil supplied to the second passage 132 is supplied to a portion of the bearing collar of the camshaft 91, 92 via the bearing oil supply passage.

That is, the first passage 131, the second passage 132, the third passage
By passage 133, left branch passage 134, right branch passage 135, and oil supply passages 121, 122, 123,
The oil in the main oil passage is first supplied to the hydraulic lash adjuster 72 of the central intake valve 32, and then to the intake valves 31. 33 hydraulic lash adjuster 71.73
A dedicated oil passage 40 is configured to supply oil to the oil.

Further, a plug hole 101 is provided through the cylinder head 2 and the cam carrier member 3 above the combustion chamber 7, and an ignition plug 102 is placed in this plug hole so that its ignition point 102a is directed toward the combustion chamber 7. installed. The plug hole 101 and the spark plug 102 are provided parallel to the valve shafts of the exhaust valves 41 and 42 so that the ignition point 102a is located at the center of the cylinder bore of the combustion chamber 7.

Furthermore, an injector 103 for injecting fresh fuel into the cylinder head 2 above the intake boat is provided.

Note that the three swing arms 81 to 83 for the intake valves are the same member, and the parts are made common. In that case, the three swing arms 81 are attached to the engine.
Although it is conceivable to align the centers of the rollers of the swing arms 8] to 83, we intentionally do not do so to avoid increasing the size of the swing arms 8] to 83.

Therefore, in the above embodiment, the intake valves 31 to 33
is inclined to the left side of the cylinder bore toward the end of the valve shaft,
Exhaust valve 41. ．． 42 is tilted toward the right side of the cylinder bore toward the end of the valve shaft, so the lower surfaces of the valve heads of the intake and exhaust valves are arranged in a chevron shape, creating a vent roof type that improves combustion efficiency without forming a quench area. A combustion chamber 7 can be formed.

In addition, the hydraulic lash adjuster 7 of the intake valves 31 to 33
Since the valves 1 to 73 are arranged in a staggered manner, (1) the swing arm 82 of the central intake valve 32 and the hydraulic lash unstable staff 2 can be placed using the space closer to the center of the cylinder bore than the intake valves 31 to 33;

■ In the space farther from the cylinder bore center than the intake valves 31 to 33, the swing arms 81, 83 of the intake valves 31 and 33 on both sides and the hydraulic lash adjuster 7
1.73 engine longitudinal distance can be set small.

For these reasons, the engine can be made compact.

Furthermore, since the hydraulic lash adjusters 71.73 of the intake valves 31.33 on both sides are arranged on the advancing side of the camshaft rotation direction, the lever ratio of the swing arm 81°83 becomes small, and the hydraulic lash adjusters 71.73 of the intake valves 31.33 on both sides Supporting force is suppressed. Therefore, the durability and reliability of the hydraulic lash adjusters 71, 73 can be improved, and the rotational limit of the engine can be increased. Moreover, since the point where the supporting force is maximum is set on the opening side of the valve,
The jump phenomenon when the intake valves 31 and 33 are closed can be suppressed, and the timing at the end of intake can be maintained accurately over the entire engine rotation range.

On the other hand, the hydraulic lash adjuster 7 of the central intake valve 32
2 is arranged on the lag side in the rotational direction of the camshaft and has a large supporting force, but this hydraulic lash adjuster 7
2 is connected to oil in the main oil passage or other hydraulic lash adjusters 71, 73, 74.
Since the oil pressure is supplied before the oil pressure 75, the oil pressure acts stably and the inner sleeve 112 reciprocates smoothly. As a result, the durability and reliability of the hydraulic lash adjuster 72 are improved.

Moreover, since the hydraulic lash adjuster 72 of the central intake valve 32 is inclined at a predetermined angle in the direction along the supporting force with respect to the cylinder bore center line, no lateral force is applied to the inner sleeve 12 of the hydraulic lash adjuster 72. . Therefore, the inner sleeve 112 reciprocates smoothly without vibrations such as swinging vibrations. As a result, it is possible to avoid uneven wear on the sliding contact surface of the inner sleeve, and from this aspect as well, the durability and reliability of the hydraulic lash adjuster 72 can be improved, and the rotational limit of the engine can be increased.

In that case, in order to maintain the compactness of the engine regardless of the inclined arrangement of the hydraulic lash adjuster 72,
Connect the plug hole 101 to the hydraulic lash adjuster 72.
In order to escape, the exhaust valves are arranged at an angle so as to be parallel to the exhaust valves 41 and 42. However, since the ignition point 102a of the spark plug 102 is located at the center of the cylinder bore of the combustion chamber 7, the flame propagation distance in the radial direction of the cylinder bore becomes uniform, and the improvement in combustion efficiency, which is a characteristic of the pent-roof combustion chamber 7, is sufficiently achieved. can.

In addition, the passage portion 1 of the first passage 131 is provided in the cylinder head 2.
By providing 31b and 131c, the outer walls of the passage portions 131b and 131c function as ribs along the outer wall of the cylinder head 2, so the rigidity of the cylinder head 2 is improved and the tightening force of the head bolt is transferred to the cylinder block. 1 can be effectively communicated.

In the above embodiment, three intake valves are provided, but three exhaust valves may be provided.

(Effects of the Invention) As explained above, according to the engine valve train of the present invention, three intake valves or exhaust valves are driven by the qi-camshaft via the swing arm for each cylinder. In addition, among the three valves, the central valve and the two valves on both sides are arranged so as to be shifted in the direction perpendicular to the camshaft, and a hydraulic lash adjuster having a support part that receives the swing arm of the central valve is provided. The hydraulic run-your-adjuster, which has support parts that receive the swing arms of the valves on both sides, is installed on the leading side of the camshaft rotation direction, and the oil in the main oil passage is first moved to the center. A dedicated oil passage is provided to supply oil to the hydraulic lash adjuster of the valve, and then to the hydraulic lash adjusters of the valves on both sides.The staggered arrangement of the hydraulic lash adjusters and swing arms allows the engine to be made more compact. The durability and reliability of the hydraulic lash adjuster can be improved by stably applying hydraulic pressure to the hydraulic lash adjuster of the central valve, which has a large lever ratio and a large supporting force.

[Brief explanation of drawings]

1 to 8 show embodiments of the present invention, and FIG. 1 shows a second embodiment of the present invention.
2 is a plan view of the cylinder head, FIG. 3 is a plan view of the cam carrier member, and FIG. is a sectional view taken along the line II-IV in Fig. 7, Fig. 5 is a sectional view taken along the line V-v in Fig. 7, Fig. 6 is a sectional view taken along the line Vl-Vl in Fig. 7, and Fig. 7 is a plane around the cylinder. The perspective view, FIG. 8, is an enlarged longitudinal sectional side view of the hydraulic lash adjuster. Further, FIG. 9 is an explanatory diagram for explaining the supporting force, and FIG. 10 is an experimental result diagram for explaining the difference in the supporting force. 31,, 32. 3 71, 72. 7 81, 82. 8 1 5...Cylinder 3...Intake valve 3...Hydraulic lash adjuster 3...Swing arm...Camshaft 3...Pivot (support part)] 21...Oil supply passage 122 ...Oil supply passage 123...Oil supply passage 131...First passage 132...Second passage 133...Third passage 134...Left branch passage 135...Right branch passage 140. ...Dedicated oil passage 8 Fig. 6 Fig. 8 Prisoner rotation angle Fig. 10 Fig. 9

Claims (1)

[Claims] (1) In an engine valve train equipped with three intake valves or exhaust valves driven by a single camshaft via a swing arm for each cylinder, the central valve of the three valves is and two valves on both sides are arranged offset in the direction orthogonal to the camshaft, and a hydraulic lash adjuster having a support part that receives the swing arm of the central valve is arranged on the lagging side in the rotational direction of the camshaft. A hydraulic lash adjuster with a support part that receives the swing arm of the valve is arranged on the advancing side in the rotational direction of the camshaft, and oil in the main oil passage is first supplied to the hydraulic lash adjuster of the central valve, and then to the valves on both sides. A valve train for an engine, characterized by having a dedicated oil passage for supplying oil to a hydraulic lash adjuster.