JPH05256116A - Valve system of internal combustion engine - Google Patents

Abstract

PURPOSE:To prevent leakage of oil and breakage of a sub rocker arm by providing engaging holes on sub-rocker arms for low and high speed respectively, providing a rock pin between penetrating hole and the engaging hole of each rocker shaft, and fixing the cover, made of sheet metal, of the engaging hole by a snap ring. CONSTITUTION:A valve system is provided with rocker arms 34, 35 for low and high speed. For example, a roller bearing 38 is installed and an arm part is provided on the rocker arm 34 for low speed. The roller bearing 38 is brought in contact with a cam 14 for low speed to drive the rocker arm 34. A rock pin 52 is mounted in the penetrating hole 51 of a rocker shaft 22 to be engaged with the engaging 55 of the rocker arm 34. The cover 201, made of sheet metal, of the engaging hole 55 is fixed by a snap ling 202. It is thus possible to prevent leakage of oil and breakage of a sub-rocker arm since the cover 201 made of sheet metal follows deformation of the engaging hole 55.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a valve operating system for an internal combustion engine, which controls the operation of an intake valve and an exhaust valve provided in an automobile engine, for example.

[0002]

2. Description of the Related Art In general, suction and
For the opening / closing control of the exhaust valve, the opening / closing timing is set according to the operating state obtained from the engine speed and the accelerator pedal depression amount.

By the way, the above-mentioned valve device is devised so as to reduce fuel consumption at low speed and to perform efficient intake / exhaust at high speed according to the operating condition. ..

As one of the above-mentioned measures, for example, in an OHC type valve device, a spring integral with the camshaft is built in between the camshaft and the drive pulley, and the camshaft responds to the movement of the crankshaft. The phase of
There is a structure that changes the camshaft by slightly twisting it to change the opening / closing timing or the opening / closing lift according to the load condition of the engine (for example, published by Grand Prix Publishing Co., Ltd., "Mechanism Research Encyclopedia", page 47). Variable valve timing "column).

[0005]

However, in the above-mentioned structure, the structure for causing the phase change of the camshaft is complicated and it depends on the flexural deformation force of the spring, so that the phase change is caused. Not only is the amount unstable, but a new mechanism for holding the amount of change is required.

[0006]

The structure of the present invention for solving the above-mentioned problems includes a camshaft having a low speed cam and a high speed cam mounted thereon, and a rocker shaft arranged in parallel with the camshaft. A main rocker arm whose base end is integrally attached to the rocker shaft and whose swing end faces the upper end of the intake or exhaust valve, and a base end which is rotatably pivoted on the rocker shaft and contacts the low speed cam. The first roller bearing is provided at the swing end
Sub-rocker arm, a second sub-rocker arm whose base end is rotatably pivotally attached to the rocker shaft, and a roller bearing which is in contact with the high-speed cam is provided at a swing end, and the first and second sub-rocker arms are provided. An engaging hole penetrating from the center position in the diametrical direction of the sub-rocker arm toward one side, a hydraulic passage formed along the axial direction in the axial center portion of the rocker shaft, and inside the rocker shaft, A through hole which is formed in a state orthogonal to the hydraulic passage and faces the engaging hole when the base circle of the cam faces the roller bearing; and the through hole and the engaging hole which are provided in the through hole. It is possible to project and retract between the and, and in the normal state, either one of the positions for positioning the head inside the through hole or the engaging hole is set, and the change in hydraulic pressure to the hydraulic passage is set. According to A lock pin for releasing the position; and a hydraulic control means for setting a hydraulic pressure in the hydraulic passage according to low speed and high speed operation of an internal combustion engine, the lock pin having an oil passage connected to the hydraulic passage, and the engagement The lid of the engaging hole of the hole is formed of sheet metal, and the lid is fixed to the sub rocker arm by a snap ring.

[0007]

According to the present invention, by setting the pressure in the hydraulic passage in accordance with the operating state of the internal combustion engine, the lock pin in the rocker shaft is set to project or retract, and the first or second lock pin is set.
The sub rocker arms of the above are selectively integrated with the rocker shaft or released from the integration, and further, both of these sub rocker arms are set to a non-cylinder setting by setting the transmission of the driving force to the rocker shaft to the disconnected state. Be seen. The shape of the lid made of sheet metal also follows the deformation when a load is applied to the engagement hole.

[0008]

Embodiments of the present invention will now be described in detail with reference to the drawings.

FIG. 1 is a main part of a cylinder head representing a valve operating system for an internal combustion engine according to an embodiment of the present invention (AA in FIG. 2).
Section, center of cylinder head in FIG. 2 (BB in FIG. 10)
FIG. 3 is a cross section, FIG. 3 is a plan view of a valve train with a cylinder deactivation mechanism, and FIG.
C-C cross section, FIG. 5 is a D-D cross section of FIG. 3, FIG. 6 is an exploded perspective view of the valve operating device, FIG. 7 is a cross section showing a switching mechanism of the valve operating device, and FIG. 9, FIG. 9 is an explanation of the operation of the switching mechanism, FIG. 10 is a cross section of the valve operating device without the cylinder deactivation mechanism, and FIG.
Shows the plane of the cylinder head.

The internal combustion engine of this embodiment is a double-over-head camshaft type engine (DOHC) having two camshafts in the cylinder head, and has two intakes.
It is a 4-cylinder engine with two valves and exhaust.

As shown in FIGS. 3 to 5 and 11, the cylinder head 11 is provided with a pair of intake camshaft 12 and exhaust camshaft 13 which are parallel to each other along the longitudinal direction thereof. A low speed cam 14 with a small lift amount and a high speed cam 1 with a large lift amount for each cylinder.
5 are integrally formed. The pair of camshafts 12 and 13 are fixed to the upper part of the cylinder head 11 by bolts 18 and 19 while being held by the upper part of the camshaft housing 16 and the plurality of cam caps 17. It is rotatably supported.

The cylinder head 11 has a pair of intake rocker shafts 21 and exhaust rocker shafts 22 which are parallel to each other along the longitudinal direction of the cylinder head 11 and are parallel to the pair of cam shafts 12 and 13. Are provided for each. The pair of rocker shafts 21 and 22 is held by the lower portion of the camshaft housing 16 and the plurality of rocker shaft caps 23, and the cylinder head 11 is fixed by the bolts 19 and 24.
The cylinder head 11 is rotatably supported by being fixed to the lower part of the. A cylinder head cover 25 is fixed to the upper part of the cylinder head 11.

Each rocker shaft 21, 22 has a valve operating device which can be switched between a valve opening / closing timing for high speed operation and a valve opening / closing timing for low speed operation, a valve opening / closing timing for high speed operation, and a valve opening / closing timing for low speed operation. It is equipped with a valve operating device which can be switched to the cylinder and can be deactivated during low load operation. That is, as shown in FIG. 11, the valve operating devices 31 of the upper and lower two cylinders of the four cylinders have a cylinder deactivating mechanism, and the valve operating devices 32 of the central two cylinders do not have a cylinder deactivating mechanism.

Here, the valve operating device 31 with the cylinder deactivating mechanism will be described. As shown in FIG. 6, the exhaust rocker shaft 22 has a T-shaped main rocker arm 33 in plan view, and low-speed rocker arm 34 and high-speed rocker arm 35 as first and second sub-rocker arms on both sides thereof. Is installed. The base end of the main rocker arm 33 is integrally fixed to the rocker shaft 22 by, for example, spline connection, and an adjusting screw 36 is attached to the swinging end of the main rocker arm 33 by an adjusting nut 37. It is in contact with the upper end of an exhaust valve 80 described later.

On the other hand, the low-speed rocker arm 34 has its base end pivotally attached to the rocker shaft 22 and is rotatably supported. A roller bearing 38 is attached to the rocking end of the low-speed rocker arm 34. The cam 14 can be engaged. Similarly, the base end of the high-speed rocker arm 35 is also rotatably supported by being pivotally attached to the rocker shaft 22, and a roller bearing 39 is attached to the swing end thereof. The cam 15 can be engaged.

Further, as shown in FIG. 5, the low-speed rocker arm 34 and the high-speed rocker arm 35 are integrally provided with arm portions 40 and 41, respectively, on the opposite side to the swinging end to which the roller bearings 38 and 39 are attached. The lost motions 42 and 43 act on the arm portions 40 and 41. The lost motions 42 and 43 are a cylinder 44 and a plunger 45 fixed to the cam cap 17,
Composed of a compression spring 46 and a plunger 45
5 presses the arm portions 40 and 41 to urge the rocker arms 34 and 35 shown on the left side in FIG. 5 clockwise and the rocker arms 34 and 35 shown on the right side counterclockwise, respectively. ing.

Therefore, the low speed rocker arm 34 is usually used.
And the rocker arm 35 for high speed has lost motion 4
2, 43, the roller bearings 38, 39 are in contact with the outer peripheral surfaces of the low speed cam 14 and the high speed cam 15 of the cam shaft 13, and when the cam shaft 13 rotates, the cams 14, 15 act. Then, the low speed rocker arm 34 and the high speed rocker arm 35 can be swung.

As shown in FIG. 7, the low speed rocker arm 34 and the high speed rocker arm 35 can rotate integrally with the rocker shaft 22 by the switching mechanism 50. A through hole 51 is formed in the rocker shaft 22 at a position corresponding to the low speed rocker arm 34 along the radial direction thereof. A lock pin 52 is movably mounted in the through hole 51 and a biasing means receiving member is provided. It is urged in one direction by a compression spring 54 as a biasing means supported by a spring seat 53 as a seat. On the other hand, an engaging hole 55 is formed in the low speed rocker arm 34 at a position corresponding to the through hole 51 of the rocker shaft 22, and a compression spring 54 is formed in the engaging hole 55.
The head portion of the lock pin 52 urged by is engaged. A hydraulic passage 56 communicating with the through hole 51 is formed in the rocker shaft 22 along the axial direction thereof, and the lock pin 52 has an opening on the side communicating with the hydraulic passage 56 and engaging with the engaging hole 55. An oil passage 57 is formed.

The structure of the low speed rocker arm 34 is shown in FIG.
It will be described in more detail with reference to FIG. 12 is a detailed view of an arrow X part in FIG. 5, FIG. 13 is a detailed view of an arrow Z part in FIG. 12, FIG. 14 is a cross section of the lid, FIG. 15 is a perspective view of the snap ring, FIG. 16 is a cross section of the rocker shaft, and FIG. 17 shows a cross section of the rocker shaft representing the through hole, and FIG. 18 shows a cross section of the switching mechanism in a state where the low speed rocker arm 34 is inverted.

As shown in FIGS. 12 and 13, the engaging hole 5
A lid 201 is fitted to the gear 5, and the lid 201 is fixed to the low speed rocker arm 34 by a snap ring 202. The lid 201 is made of sheet metal, and as shown in FIG. 14, the bottom edge 201a is inclined at an angle α. The upper side of the lid 201 is fixed to the low speed rocker arm 34 by the snap ring 202 shown in FIG.

The low speed rocker arm 34 is used for the low speed cam 1.
When rotated by 4, the engaging hole 55 is repeatedly subjected to tensile load by the lock pin 52, and elastic deformation is repeated. Since the lid 201 is made of sheet metal, the lid 201 is deformed following the deformation of the engagement hole 55, and the lid 201 does not come off and the low speed rocker arm 34 does not have a crack or a gap.

As shown in FIGS. 12, 16 and 17,
An oil passage 203 that guides the pressure oil from the hydraulic passage 56 to the oil passage 57 is formed on the inner periphery of the through hole 51. Therefore, the lock pin 52 can be formed in a cylindrical shape, and the lock pin 52 can be prevented from being broken and the reliability can be improved.

As shown in FIG. 16, the diameter T of the spring seat 53 of the lock pin 52 is set larger than the diameter t of the head portion inserted into the engagement hole 55. As a result, as shown in FIG. 18, the low-speed rocker arm 3 is used at the time of assembly or the like.
Even if 4 is reversed and the spring seat 53 and the engagement hole 55 are opposed to each other, the spring seat 53 does not fit into the engagement hole 55 due to the urging force of the compression spring 54.

On the other hand, a through hole 58 is formed in the rocker shaft 22 along the radial direction at a position corresponding to the high speed rocker arm 35, and a lock pin 59 is movably mounted in the through hole 58. , Compression spring 6
It is biased in one direction by 0. On the other hand, the high-speed rocker arm 35 has a through hole 5 for the rocker shaft 22.
The engaging hole 61 is formed in one corresponding to
9 is pulled out from the engagement hole 59 by the compression spring 60. A hydraulic passage 62 communicating with the through hole 58 is formed in the rocker shaft 22 along the axial direction thereof, and an oil passage 63 communicating with the end of the through hole 58 opposite to the engaging hole 59 is formed. Has been done.

Therefore, as shown in FIG. 9 (a),
The low speed rocker arm 34 becomes integral with the rocker shaft 22 by the lock pin 52 urged by the compression spring 54 engaging with the engagement hole 55, and can rotate together with the main rocker arm 33 via the rocker shaft 22. It has become. On the other hand, in the high-speed rocker arm 35, the lock pin 59 urged by the compression spring 60 comes out from the engagement hole 61, and the engagement with the rocker shaft 22 is released so that it does not rotate integrally with the rocker shaft 22. It has become. Therefore, although the low speed cam 14 and the high speed cam 15 swing the low speed rocker arm 34 and the high speed rocker arm 35,
Only the driving force transmitted from the low speed rocker arm 34 is transmitted via the rocker shaft 22 to the main rocker arm 33.
And the main rocker arm 33 can be rocked.

When hydraulic pressure is supplied to the hydraulic pressure passages 56 and 62 of the rocker shaft 22, as shown in FIG. 9B, in the low speed rocker arm 34, the pressure oil flows through the oil passage 57. The lock pin 52 flows toward the engagement hole 55 side of the through hole 51, and the lock pin 52 is pulled out from the engagement hole 55 against the biasing force of the compression spring 54. Then, low-speed rocker arm 3
4 and the rocker shaft 22 are disengaged so that they do not rotate together. On the other hand, high-speed rocker arm 3
5, the pressure oil flows through the oil passage 63 to the opposite side of the through hole 58 from the engaging hole 61, and the lock pin 59 is engaged with the engaging hole 61 against the biasing force of the compression spring 54. To combine.
Then, the high-speed rocker arm 35 and the rocker shaft 22 are engaged with each other, so that both can rotate together. Therefore, the low speed cam 14 and the high speed cam 15 swing the low speed rocker arm 34 and the high speed rocker arm 35, but only the driving force transmitted by the high speed rocker arm 35 is transmitted via the rocker shaft 22. The main rocker arm 33 is transmitted to the arm 33 and can swing.

The hydraulic passage 5 of the rocker shaft 22
When hydraulic pressure is supplied only to 6, as shown in FIG.
In the low speed rocker arm 34, the pressure oil passes through the through hole 5
1 toward the engagement hole 55 side to lock the lock pin 52 into the engagement hole 55 side.
Then, the low-speed rocker arm 34 and the rocker shaft 22 are disengaged from each other so that they do not rotate together. On the other hand, in the high-speed rocker arm 35,
The compression spring 60 causes the lock pin 59 to engage the engagement hole 6
The locker shaft 22 is disengaged from the locker shaft 22 and does not rotate integrally. Therefore, the low speed cam 14 and the high speed cam 15 are the low speed rocker arm 34.
Although the rocker arm 35 for high speed is swung, the driving force thereof is not transmitted to the rocker shaft 22, and the main rocker arm 33 can be in a cylinder deactivated state without operating.

Further, in the valve operating device 32 without the cylinder deactivating mechanism, as shown in FIG.
The low-speed rocker arm 64 has a T-shape in plan view
Also, a high-speed rocker arm 65 is attached. The base end of the low speed rocker arm 64 is the rocker shaft 2
It is firmly fixed to the two. A roller bearing 66 is attached to the swinging end of the low speed rocker arm 64 so that the low speed cam 14 can be engaged, and an adjusting screw 67 is used to adjust the nut 68.
And the lower end of the adjusting screw 67 is in contact with the upper end of an exhaust valve 80 described later.

On the other hand, the high-speed rocker arm 65 has its base end pivotally attached to the rocker shaft 22 and is rotatably supported. A roller bearing 69 is attached to the rocking end of the rocker arm 65. High speed cam 15
Can be engaged. Further, an arm portion 70 is integrally formed on the high-speed rocker arm 65 on the side opposite to the swing end to which the roller bearing 69 is attached. The lost motion 71 acts on the arm portion 70, and the high-speed rocker arm 65 is operated. 65 is biased in one direction. Furthermore, the high-speed rocker arm 65 can be rotated integrally with the rocker shaft 22 by the switching mechanism 72. That is, a through hole 73 is formed in the rocker shaft 22 at a position corresponding to the high speed rocker arm 65, and a lock pin 74 is movably mounted and urged and supported by a compression spring 75. On the other hand, an engaging hole 76 is formed in the high speed rocker arm 65, and the lock pin 74 is pulled out from the engaging hole 76 by the compression spring 75. And rocker shaft 2
A hydraulic passage 77 communicating with the through hole 73 is formed in the axial direction 2, and an oil passage 78 communicating with an end of the through hole 73 on the opposite side to the engaging hole 76 is formed.

Therefore, the rocker arm 65 for high speed is usually used.
The lock pin 74 is pulled out from the engagement hole 76 by the compression spring 75, the engagement with the rocker shaft 22 is released, and the lock pin 74 does not rotate integrally with the rocker shaft 22. Therefore, the low speed cam 14 and the high speed cam 15 swing the low speed rocker arm 64 and the high speed rocker arm 65, but the driving force of the low speed cam 14 is transmitted to the exhaust valve 80, which will be described later. Can be rocked. When hydraulic pressure is supplied to the hydraulic passage 77 of the rocker shaft 22, in the high-speed rocker arm 65, the pressure oil flows through the oil passage 78 to the opposite side of the through hole 73 from the engaging hole 76 and locks. The pin 59 is engaged with the engagement hole 76. Then, the high speed rocker arm 65 and the rocker shaft 2
2 is engaged, and the rocker shaft 22 and the rocker shaft 22 can rotate together. Therefore, the high-speed cam 15 swings the high-speed rocker arm 35, and its driving force is transmitted to the exhaust valve 80 via the rocker shaft 22 and the low-speed rocker arm 64 to swing the exhaust valve 80. You can do it.

In the above description of the valve operating devices 31 and 32, only the exhaust side has been described. However, the intake side has the same structure, and each camshaft has a valve opening / closing timing for intake and exhaust. Only the forming positions of the cams 12 and 13 of the cams 14 and 15 in the circumferential direction are different.

By the way, as shown in FIG. 5, the intake valve 79 and the exhaust valve 80 are movably mounted on the cylinder head 11, and the valve springs 81 and 82 close the intake port 83 and the exhaust port 84. Therefore, by pushing the upper ends of the intake valve 79 and the exhaust valve 80 by driving the main rocker arm 33 (low speed rocker arm 64) described above, the intake port 83
Also, the exhaust port 84 can be opened and closed to communicate with the combustion chamber 85.

As shown in FIGS. 1, 2, and 11, a hydraulic control device 86 for operating the switching mechanisms 50, 72 of the valve operating device 31 is provided at the rear portion (upper portion in FIG. 11) of the cylinder head. It is provided. The hydraulic control device 86 includes an oil pump 87, an accumulator 88, a high speed switching oil control valve 89, and a cylinder switching oil control valve 90.

The oil pump 87 and the accumulator 88 are located between the intake camshaft 12 and the exhaust camshaft 13, and both are arranged side by side and the axial direction of both is horizontal. ing. That is, the oil pump 87 is provided on the upper side of the cam cap housing 16 and the cam cap 17 at the rearmost portion of the cylinder head 11.
The cylinder 91 is horizontally movable, is biased and supported by a compression spring 92, and is fixed by a bolt 94 via a cover 93. A plunger 96 acts on the cylinder 91 of the oil pump 87 via a compression spring 95, and the plunger 96 can be driven by an oil pump cam 97 integrally formed at one end of the intake camshaft 12. It has become.

A cylinder 98 of an accumulator 88 is horizontally movable downward on the side portions of the cam cap housing 16 and the cam cap 17, and is biased and supported by a compression spring 99. Are fixed by bolts 94. The cylinder 91 of the oil pump 87 and the cylinder 98 of the accumulator 88 have the same diameter and can be shared.
Further, the high speed switching oil control valve 89 and the cylinder deactivation switching oil control valve 90 are attached to the cylinder head 11.

As shown in FIGS. 1, 2 and 8, the high speed switching oil control valve 89 is directly connected to the main oil pump of the engine (not shown) via an oil passage 100 and hydraulic pressure is supplied via an oil passage 101. It is connected to the passage 62. The cylinder deactivation switching oil control valve 90 is connected to the accumulator 88, the oil pump 87, and the main oil pump via the oil passage 102, and is connected to the hydraulic passage 56 via the oil passage 103. Further, each oil control valve 89, 90 can be operated by a control signal of the engine control unit 104.

The switching mechanism 72 of the valve operating device 32 can also be operated by the hydraulic control device 86 like the valve operating device 31, and the hydraulic passage 77 of the rocker shaft 22 has an oil passage (not shown). The oil control valve 89 is connected via. Further, as shown in FIG. 2, a hollow plug tube 105 is erected for each cylinder in the cylinder head 11, and the spark plug 106 is provided inside each plug tube 105.
Are mounted, and the tip end faces each combustion chamber 85.

The operation of the four-cylinder engine of this embodiment will be described below. Engine control unit 104
Detects the operating state of the engine based on the detection results of various sensors, and if the engine is in a low-speed traveling state, selects a cam profile suitable for it. In this case, the engine control unit 104 outputs a control signal to each oil control valve 89, 90, and
Close 0. Then, the pressure oil is not supplied to the hydraulic passages 56, 62, 77, and the valve gear 31 is locked by the lock pin 52 by the lock pin 52 as shown in FIG. 9A.
4 and the rocker shaft 22 are integrated, and the engagement between the high-speed rocker arm 35 and the rocker shaft 22 is released. Therefore, when the cam shafts 12 and 13 rotate, the low speed cam 14 causes the low speed rocker arm 34 to rotate.
Oscillates, and the driving force is transmitted to the main rocker arm 33 via the rocker shaft 22 to oscillate, and the pair of adjusting screws 36 at the oscillating ends cause the intake valve 79 and the exhaust valve 80 to move. To drive. On the other hand, the valve operating device 32, as shown in FIG.
When the engagement between the high speed rocker arm 65 and the rocker shaft 22 is released and the cam shafts 12 and 13 rotate, the low speed cam 14 causes the low speed rocker arm 64 to rotate.
Swings, and the pair of adjusting screws 67 at the swinging end drive the intake valve 79 and the exhaust valve 80. In this way, the intake valve 79 and the exhaust valve 80 are driven at the valve opening / closing timing corresponding to the low speed operation, and the engine is operated at the low speed.

When the engine control unit 104 detects the high speed running state of the engine, the engine control unit 104 causes the oil control valves 8 to operate.
A control signal is output to 9 and 90 to open the valves 89 and 90. Then, pressure oil is supplied to the hydraulic passages 56, 62, 77, and the valve operating device 31 is operated when the engine runs at high speed.
As shown in FIG. 9B, the pressure oil causes the lock pin 52 to be pulled out from the engagement hole 55, and the engagement between the low speed rocker arm 34 and the rocker shaft 22 is released.
Further, the lock pin 59 is engaged with the engagement hole 61 so that the high speed rocker arm 35 and the rocker shaft 22 are integrated. Therefore, the high-speed cam 15 swings the high-speed rocker arm 35, and further swings the main rocker arm 33 to drive the intake valve 79 and the exhaust valve 80.
On the other hand, in the valve gear 32, the lock pin 59 is engaged with the engagement hole 76 by the supplied pressure oil, and the high speed rocker arm 65 and the rocker shaft 22 are integrated. Therefore, the high-speed cam 15 allows the high-speed rocker arm 35 to move.
Swings to drive the intake valve 79 and the exhaust valve 80. In this way, the intake valve 79 and the exhaust valve 80
Drives at the valve opening and closing timing corresponding to high speed operation,
The engine runs at high speed.

The engine control unit 1
When 04 detects an idle operation state or a low load running state of the engine, two of the four cylinders are stopped to reduce fuel consumption. That is, the engine control unit 104
Outputs a control signal to each oil control valve 89, 90 to open only the valve 90. Then, the hydraulic passage 5
The pressure oil is supplied to 6, and in the valve gear 31, the engagement between the low speed rocker arm 34 and the rocker shaft 22 is released, as shown in FIG. 9C. Therefore, the low speed cam 14
The driving force of the high-speed cam 15 is the main rocker arm 3
3 is not transmitted, and the valve operating device 31 does not operate and enters a cylinder deactivated state. On the other hand, in the valve operating device 32, the low speed rocker arm 64 swings by the low speed cam 14 to drive the intake valve 79 and the exhaust valve 80. In this way, the engine is operated by driving only the intake valve 79 and the exhaust valve 80 of the valve gear 32.

As described above, the engine valve operating system of this embodiment includes the oil pump 87 for operating the switching mechanism 50 of the valve operating system 31, the accumulator 88, the oil control valves 89, 90, etc. 8
6 is an intake camshaft 12 and an exhaust camshaft 13
Between the oil pump 87 and the accumulator 8
Since 8 is arranged vertically, the oil pump 87 and the accumulator 88 can be efficiently arranged, the layout of the cylinder head 11 becomes compact, and a part of the engine protrudes upward or the height of the engine increases. It will not be lost.

Since the cylinders 91 and 98 of the oil pump 87 and the accumulator 88 have the same diameter, not only can the cylinders 91 and 98 be shared,
The peripheral members can be shared and the cost can be reduced.

Further, since the lid 201 made of sheet metal is attached to the engaging hole 55, even if the engaging hole 55 is deformed, the lid 201 is deformed following the deformation, and the lid 201 is disengaged, or the rocker arm for low speed is used. There is no crack or gap in 34. For this reason, oil leakage does not occur, and the low-speed rocker arm 34 is not likely to be damaged.

[0044]

As described above, according to the present invention, the low-speed and high-speed sub-rocker arms are pivotally attached to the rocker shaft, the projecting and retractable connecting plunger is arranged between the sub-rocker arms, and the connecting rocker arm is connected. The plunger is set in each of the low-speed and high-speed operating states and the load / crash setting is performed to set the transmission state of the driving force between the rocker shaft and the sub-rocker arm. It is possible to control the opening / closing timing of the valve and the cylinder deactivation setting by stopping the opening / closing of the valve by a common mechanism. Therefore, it is possible to realize it by a simple common mechanism without newly providing a fuel consumption reduction mechanism and a mechanism for improving intake / exhaust efficiency.

Further, in the above-mentioned mechanism, the projecting and retracting operation of the connecting plunger is such that the through hole on the rocker shaft side engages with the sub rocker arm side only when the roller bearing of the sub rocker arm faces the base circle of the cam. Since the holes are aligned with each other, the posture of the connecting plunger does not change, so that highly reliable driving force transmission control can be performed.

Further, since the lid of the engaging hole is formed of sheet metal,
It deforms following the deformation of the engagement hole, and the lid does not come off and the sub rocker arm does not have cracks or gaps. For this reason, oil leakage does not occur and there is no fear of damage to the sub rocker arm.

[Brief description of drawings]

FIG. 1 is a sectional view of a main part (AA in FIG. 2) of a cylinder head showing a valve operating system for an internal combustion engine according to an embodiment of the present invention.

FIG. 2 is a sectional view of the center of the cylinder head (BB in FIG. 11).

FIG. 3 is a plan view of a valve train having a cylinder deactivation mechanism.

FIG. 4 is a sectional view taken along line CC of FIG.

5 is a cross-sectional view taken along line DD of FIG.

FIG. 6 is an exploded perspective view of a valve train.

FIG. 7 is a cross-sectional view showing a switching mechanism of the valve gear.

FIG. 8 is a hydraulic path diagram of the valve gear.

FIG. 9 is an operation explanatory view of a switching mechanism.

FIG. 10 is a cross-sectional view of a valve train without a cylinder deactivation mechanism.

FIG. 11 is a plan view of a cylinder head.

12 is a detailed view of an arrow X portion in FIG.

13 is a detailed diagram of an arrow Z portion in FIG.

FIG. 14 is a cross-sectional view of the lid.

FIG. 15 is a perspective view of a snap ring.

FIG. 16 is a sectional view of a rocker shaft.

FIG. 17 is a cross-sectional view of a rocker shaft showing a through hole.

FIG. 18 is a cross-sectional view of the switching mechanism with the low speed rocker arm inverted.

[Explanation of symbols]

11 Cylinder Head 12,13 Cam Shaft 14 Low Speed Cam 15 High Speed Cam 21,22 Rocker Shaft 31,32 Valve Operating Device 33 Main Rocker Arm 34,64 Low Speed Rocker Arm (First Sub Rocker Arm) 35,65 High Speed Rocker arm (second sub-rocker arm) 42, 43, 71 lost motion 50, 72 switching mechanism 51, 58, 73 through hole 52, 59, 74 lock pin 53 spring seat 55, 61, 76 engaging hole 56, 62, 77 hydraulic passage 79 intake valve 80 exhaust valve 85 combustion chamber 86 hydraulic control device 87 oil pump 88 accumulator 89 oil control valve for high speed switching 90 oil control valve for cylinder deactivation 91, 98 cylinder 97 oil pump cam 104 engine Control unit 201 lid 202 snap ring 203 oil passage

Claims (1)

[Claims] 1. A camshaft on which a low speed cam and a high speed cam are mounted, a rocker shaft arranged parallel to the camshaft, a base end of which is integrally attached to the rocker shaft, and a swing end of which is intake air or A main rocker arm facing the upper end of the exhaust valve; a first sub-rocker arm having a base end rotatably pivotally attached to the rocker shaft and having a roller bearing abutting against the low speed cam at a swing end. A second sub-rocker arm having a base end rotatably pivotally attached to the rocker shaft and provided at a swing end with a roller bearing that abuts against the high-speed cam, and the first and second sub-rocker arms. An engagement hole penetrating from the center position in the diametrical direction toward one side, and a hydraulic passage formed in the axial center portion of the rocker shaft along the axial direction. And a through hole that is formed inside the rocker shaft in a state orthogonal to the hydraulic passage and that faces the engaging hole when the base circle of the cam faces the roller bearing, and is provided in the through hole. , Between the through hole and the engaging hole can be projected and retracted, and in a normal state, one of the positions for positioning the head inside the through hole or the engaging hole is set. , A lock pin that releases the position according to a change in hydraulic pressure to the hydraulic passage, and an oil passage connected to the hydraulic passage to set the hydraulic pressure to the hydraulic passage according to low speed and high speed operation of the internal combustion engine. And a hydraulic control means for performing the operation, wherein a lid of the engagement hole is formed of a metal plate, and the lid is fixed to the sub rocker arm by a snap ring.