JPH0874542A - Valve rest device of four-cycle engine - Google Patents

Abstract

PURPOSE: To realize a valve rest device of an engine, wherein processing of an oil passage can be easily performed in a multiple-cylinder engine, and the structure of the oil passage is simple. CONSTITUTION: In a valve rest device of an engine wherein at least one part of a plurality of valves 11a to 11c is held in the closing position according to the engine operating state, a cam carrier 20 for jorunaling a cam shaft 16 is so formed as to be separated from a cylinder head 4, and lifter guide holes 20a, 20c are formed on the cam carrier 20, and valve lifters 21a, 21c for transmitting the operation of the cam shaft to a valve shaft are slidably inserted and arranged into the lifter guide holes 20a, 20c. And hydraulically driven-type valve rest mechanisms 18a, 18b are arranged in the valve lifters 21a, 21c, and oil passages 33d, 33e for supplying oil pressure to the valve rest mechanisms 18a, 18b are formed on the cam carrier 20.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a valve deactivating device for an engine, which is capable of holding at least a part of a plurality of valves in a closed position.

[0002]

2. Description of the Related Art In a four-cycle engine, there has been proposed a valve deactivation device capable of holding at least a part of a plurality of intake valves or exhaust valves in a closed position according to the operating state of the engine. As such a valve pause device,
Conventionally, there is a valve lifter for transmitting the operation of the cam shaft to the valve shaft, which incorporates a hydraulically driven plunger type valve pause mechanism (for example, Japanese Patent Application No. 60-24604).
(See No. 1).

[0003]

By the way, in the case of the hydraulically driven valve deactivating mechanism, an oil passage for supplying the hydraulic pressure is required. This oil passage is provided in the cylinder head as in the conventional device. It is generally formed by direct drilling. However, in the case of such a structure in which the cylinder head is directly machined, there is a problem that the cylinder head itself becomes large in size and heavy in weight, particularly in a multi-cylinder engine, which makes it difficult to handle. In addition, it is necessary to perform drilling so that it penetrates the cam chamber wall of the cylinder head, which increases the oil passage length and thus the drill length, and it is necessary to form a receiving part that supports the drill. There is also the problem of becoming complicated.

Further, depending on the structure of the oil passage and the processing method, a plurality of oil passages may be required or the shape of the oil passage may be complicated in order to construct a plurality of intake valves that can be independently suspended. There is a problem of becoming.

The present invention has been made in view of the above-mentioned conventional circumstances, and provides an engine valve shutoff device in which the oil passage can be easily processed even in the case of a multi-cylinder engine and the structure of the oil passage is simple. The purpose is to do.

[0006]

According to a first aspect of the present invention, there is provided a valve pausing device for an engine, wherein at least a part of the plurality of valves is held in a closed position in accordance with an operating state of the engine. Forming a cam carrier separable from the cylinder head, forming a lifter guide hole in the cam carrier, and slidably inserting and arranging a valve lifter for transmitting the operation of the cam shaft to the valve shaft into the lifter guide hole, A hydraulically driven valve pause mechanism is installed in the valve lifter,
The cam carrier is characterized in that an oil passage for supplying hydraulic pressure to the valve suspension mechanism is formed.

According to a second aspect of the present invention, in the first aspect, the engine is a parallel multi-cylinder engine, the cam carrier integrally forms an intake or exhaust cam carrier for all cylinders, and the oil passages are all formed. It is characterized in that the intake or exhaust oil passage for the cylinder is formed in a straight line.

According to a third aspect of the present invention, there is provided an engine valve pausing device similar to the first aspect, wherein a lifter guide hole is formed in the cylinder head, and a valve lifter for transmitting the operation of the cam shaft to the valve shaft is provided in the lifter guide hole. The valve lifter is slidably inserted and disposed, and a hydraulically driven valve deactivating mechanism is disposed in the valve lifter. The tilt angle formed by a cylinder axis of a part of the plurality of valve lifters and the tilt of at least a part of the remaining valve lifters. The angle is different, and the oil passage for supplying the hydraulic pressure to the valve stop mechanism is formed for each valve lifter having a different inclination angle.

According to a fourth aspect of the present invention, in any one of the first to third aspects, the oil passage is formed parallel to the cam shaft and in contact with the lifter guide hole. .

According to a fifth aspect of the present invention, in any one of the first to fourth aspects, one center intake valve located at the center in the cam axis direction and the first and first center intake valves located on both sides of the center intake valve in the cam axis direction. A cylinder shaft of each valve lifter including a two-side intake valve, the center intake valve lifter for the center intake valve is located closer to the anti-cylinder shaft side, and the first and second side intake valve side valve lifters are located closer to the cylinder shaft side. The oil passage for the center valve lifter is formed so as to contact the outer peripheral surface of the center lifter guide hole on the side opposite to the cylinder axis, and the oil passage for the side valve lifter is formed on the cylinder shaft side outer circumference of the side lifter guide hole. It is characterized in that it is formed so as to be in contact with the surface.

According to a sixth aspect of the present invention, in the fifth aspect, a valve lifter having a built-in valve stopping mechanism is slidably disposed in the second intake valve lifter guide hole, and the first intake valve for the first intake valve is provided. Inside the lifter guide hole, a bottomed tubular valve lifter without a valve pause mechanism is slidably arranged, and the oil passage is in contact with both the first and second side intake valve lifter guide holes. It is characterized by

[0012]

According to the first aspect of the invention, since the valve pausing mechanism is provided in the cam carrier which is separate from the cylinder head, and the oil passage to the valve pausing mechanism is formed in the cam carrier, the cylinder head itself. It is possible to solve the above-mentioned problems when forming the oil passage in the. For example, even in the case of multiple cylinders, the cam carrier itself is light in weight, so that it is easy to handle, and the oil passage length is short because it is not necessary to penetrate the cam chamber constituting wall of the cylinder head. Is short and no drill receiver is required. Further, in the invention of claim 2, since the cam carrier for the parallel multi-cylinder engine has the same structure as that of the invention of claim 1,
It is even more effective.

According to the third aspect of the present invention, since a part of the valve lifter and at least a part of the remaining part thereof have different inclination angles with respect to the cylinder axis, and the oil passage is formed for each valve lifter having a different inclination angle, a plurality of oil passages are formed. The oil passage structure is simple in the case where the valve is independently stopped. In particular, as in the invention of claim 4, each valve lifter is independently stopped only by forming the oil passage for each valve lifter having a different inclination angle so as to be in parallel with the cam shaft and in contact with the lifter guide hole. It becomes possible. By the way, in the above-mentioned conventional device, the main oil passage is formed parallel to the cam shaft at a position away from the lifter guide hole, and the branch passage from the main passage is formed in the direction perpendicular to the cam shaft. It's complicated.

According to the invention of claim 5, the center valve lifter is located closer to the non-cylinder shaft side in the case where one center intake valve and two first and second side intake valves are provided.
Since the inclination angle of each valve lifter with respect to the cylinder axis is set so that the side valve lifter is located closer to the cylinder axis side, the center valve lifter oil passage should be in contact with the outer peripheral surface of the center lifter guide hole on the opposite cylinder axis side. The oil passage for the valve lifter can be formed so as to be in contact with the outer circumferential surface of the side lifter guide hole on the cylinder shaft side, and the oil passage structure in the case where the center intake valve and the side intake valve can be independently suspended can be simple.

According to the sixth aspect of the present invention, even when only one of the first and second side intake valves is provided with the valve stopping mechanism, the oil passage can be formed so as to contact both lifter guide holes. That is, even in this case, it is only necessary to form one oil passage in parallel with the cam shaft, and the oil passage structure is simple as much as the branch passage in the direction perpendicular to the cam shaft is unnecessary.

Embodiments of the present invention will be described below with reference to the accompanying drawings. 1 to 13 are views for explaining an engine valve deactivation device according to an embodiment (first embodiment) of the invention of claims 1, 3, 7 and 9, and FIG. 1 shows the engine of this embodiment. Front view, FIG. 2 is a sectional front view showing the right side intake valve, right exhaust valve portion, FIG. 3 is a sectional front view showing the center intake valve portion, and FIG. 4 is a left side intake valve, left exhaust valve portion. Sectional front view, FIG. 5 is a plan view showing a state where the cam carrier of the cylinder head is removed, and FIGS. 6A and 6B.
Is a plan view showing the intake cam carrier and the exhaust cam carrier, FIG. 7 is a sectional side view showing the hydraulic system, and FIG.
FIG. 9 is a schematic cross-sectional plan view showing the exhaust port portion, FIG. 9 is a schematic diagram for explaining the operation, FIGS. 10, 11, and 12 are diagrams showing a valve suspension mechanism portion, and FIG. 13 is a hydraulic system diagram.

In the drawing, reference numeral 1 is a water-cooled 4-cycle 4-cylinder 5-valve engine equipped with the device of the present embodiment. A cylinder head 4 is fastened to the surface with head bolts 4e, a head cover 5 is mounted on the upper mating surface of the cylinder head 4, and the front end surface of the cylinder head 4 and the head cover 5 (front side in FIG. 1) is attached. A head side cover 6a and a block side cover 6b are detachably attached to the front end surface of the cylinder block 2. As shown in FIG. 5, the head bolt 4e includes the inter-cylinder portion and both end portions in the cam shaft direction (front,
A total of 10 pieces are arranged at the rear end portion, and the boss portion 4g portion projectingly formed on the bottom wall 4d of the cylinder head 4 is fastened.

A piston 7 is slidably inserted into four cylinder bores (cylinders) 2a formed in parallel with the cylinder block 2, and the piston 7 is connected to a crankshaft 12 by a connecting rod 8. . The crankshaft 12 is pivotally supported by a crank bearing portion 12a formed on the cylinder block 2 and a crank bearing cap 12b detachably attached to the crank bearing portion 12a.

A combustion chamber 4b is provided as a recess in a mating surface 4a of the cylinder head 4 on the cylinder block side. One side of the combustion chamber 4b around the cylinder axis A (left side in FIG. 8)
Includes one center intake valve opening 9a located at the center in the cam axis direction (vertical direction in FIG. 8) and left and right (first and second) side intake valve openings 9b and 9c located on both sides thereof. On the other side, two left and right (first and second)
Exhaust valve openings 10a and 10b are formed. An ignition plug 25 is screwed into a portion of the combustion chamber 4b slightly closer to the exhaust side from the cylinder axis A. As will be described later, intake air from the center intake valve opening 9a is directed in the cylinder A axis direction. As seen (see FIG. 8), the current flows toward the electrodes of the spark plug 25.

Here, the center, left and right side intake valve openings 9a, 9b and 9c and the left and right exhaust valve openings 10a,
10b is arranged along the inner peripheral edge of the cylinder bore 2a. Therefore, when viewed in the cam axis direction, as is apparent from FIGS. 2 to 4, the both side intake valve openings 9b and 9c are
Located at the cylinder axis A side, the center intake valve opening 9
a is located on the side opposite to the cylinder axis A (opposite to the cylinder axis). That is, as shown in FIG. 8, the distance L1 from the straight line B passing through the cylinder axis A and parallel to the cam axis to the side intake valve openings 9b and 9c and the distance L2 to the center intake valve opening 9a are L2> It is L1.

Further, the openings 9a to 9c, 10a, 10
Diameters Dic, Dis1, Dis2, De1, De2 of portions (throat portions) of valve heads 11d, 13c of each valve, which will be described later, are contacted.
Is set to have a relationship of Dic> De1 = De2> Dis1 = Dis2, that is, a relationship of Dic: De1, De2: Dis1, Dis2 = large: medium: small. The center, left and right side intake valve openings 9a, 9b and 9c are set to 9a: 9b: 9c = 46: 27: 27 in terms of the ratio of the opening areas.

Center, left and right side intake valve openings 9
a, 9b, 9c are the center, left and right side intake valves 11
a, 11b, 11c are opened and closed by the valve head 11d, and the exhaust valve openings 10a, 10b are exhaust valves 13a, 1
It is opened and closed by the valve head 13c of 3b. Then, the valve shaft 11e of each of the intake valves 11a to 11c and each of the exhaust valves 13
The valve shafts 13d of a and 13b are arranged so as to spread upward obliquely outward at a predetermined valve holding angle. In this case, the inclination angle θ1 formed by the axis B1 of the center intake valve 11a and the cylinder axis A, and the left and right side intake valves 11b, 11c.
The angle of inclination between the valve axis B2 of the cylinder and the cylinder axis A is θ2
> Θ1. That is, the center intake valve 11a is on the left,
As compared with the right side intake valves 11b and 11c, they are arranged upright.

The intake valves 11a to 11c and the exhaust valves 13a and 13b constitute the retainers 14a and 14a mounted on the upper ends or intermediate portions of the valve shafts 11e and 13d and the bottom surface of the cam chamber C of the cylinder head 4. The valve springs 14 and 15 provided between the spring seat 4c formed on the bottom wall 4d and the valve seat 4c urge the valve openings to close the valve openings.
A double coil spring is adopted as the valve spring 15 for the exhaust valve.

The intake valves 11a-11c are intake camshafts 1.
At 6, the exhaust valves 13a and 13b are opened / closed by the exhaust cam shaft 17, respectively. The intake cam shaft 16 and the exhaust cam shaft 17 extend parallel to each other in the direction perpendicular to the paper surface of FIGS. 2 to 4, and the intake and exhaust cam shafts 16 and 17 are detachably mounted in the cam chamber C. The intake and exhaust cam carriers 20 and 30 and the intake and exhaust cam caps 28 and 29 detachably attached to the carriers 20 and 30 are rotatably supported.

The intake cam shaft 16 and the intake cam shaft 17 are mounted on the front ends (right end in FIG. 7) of the intake cam shaft 17 so as to be relatively rotatable,
The exhaust timing gears 36a and 36b are connected to a first intermediate gear 39a arranged on the front end surface of the cylinder head by an upper timing chain 38a, and the first intermediate gear 39a.
A second intermediate gear 39b, which is coaxial with and rotates together with, is connected to the crank gear 37a of the crankshaft 12 by a lower timing chain 38b, and these are covered by the head side cover 6a and the block side cover 6b. The timing gears 36a and 36b are
And the crank gear 37a have the same diameter, and the first intermediate gear 3
9a is set to have the same diameter as or smaller than the timing gear 36a, and the second intermediate gear 39b is set to have a larger diameter than the crank gear 37a. In this way, the intermediate gears 39a, 39b
The intake / exhaust timing gear 36 is provided by providing the
The rotation of the crankshaft 12 can be decelerated to 1/2 and transmitted to the camshaft without increasing the diameters of a and 36b.

At the front ends of the intake and exhaust camshafts 16 and 17, an intake and exhaust variable valve timing mechanism 41 for changing the opening and closing timing of the intake and exhaust valves is provided.
42 is attached. In the variable valve timing mechanisms 41 and 42, a cylinder case 43b is mounted on the outside of a cylinder shaft 43a fixed to the front ends of the cam shafts 16 and 17, and a piston 43c is movably arranged between them. It is of structure. The cylinder shaft 43a
A support shaft (outer end portion) 43d is inserted in the support shaft 43
d is supported by the outer end support portion 6c of the head side cover 6a, and hydraulic oil is supplied to the piston 43c via an oil introduction passage 43e formed in the support shaft 43d.

Variable valve timing mechanism 41, 42
Then, if the piston 43c is moved back and forth by hydraulic pressure,
The relative angular position (phase) between the timing gears 36a and 36b and the cam shafts 16 and 17 changes, which causes the intake valve 1
1a-11c, the opening / closing timing of the exhaust valves 13a, 13b changes.

As shown in FIG. 6A, the intake cam carrier 20 is a rod-like member extending in the cam axis direction, and the first bearing portion 20 formed at both ends in the cam axis direction.
d, a second bearing portion 20e formed between the left side intake valve and the center intake valve in each cylinder, and a third bearing portion 20f formed at the boundary of each cylinder. Part 2
The portions between 0d and 20f are integrally connected by the guide boss portions 20g and 20g. This guide boss 20g
Center, left and right lifter guide holes 20a, 20b, 2
0c is formed so as to be coaxial with each valve shaft 11e of the intake valves 11a to 11c. In addition, each of the bearing portions 20d
The cam bolt 28 is attached to the cap bolt 2 up to 20 f.
It is fixed at 8a and 28b.

In this case, the cap bolt 28b arranged outside the second bearing portion 20e located between the cylinders (on the side opposite the cylinder axis A) reaches the boss portion 4f formed on the cylinder head 4. Is set (see FIG. 2).
As a result, the intake cam carrier 20 is fixed on the cylinder head 4 at the same time when the cam cap 28 is fixed by the bolt 28b. Further, the intake cam carrier 20 is also fixed to the boss portion 4f of the cylinder head 4 by the fixing bolts 28c also at the flange portion 20h formed in a proper position.

As shown in FIG. 6 (b), the exhaust cam carrier 30 is a rod-shaped member extending in the cam axis direction, and a cam bearing portion 30c is formed adjacent to the right exhaust valve of each cylinder. , The guide boss portion 3 on the cam bearing portion 30c.
0d is integrally formed, and the portion between each cam bearing portion 30c and the guide boss portion 30d is integrally connected by the passage boss portion 30e. The guide boss portion 30
Left and right lifter guide holes 30a and 30b are formed in d. Further, the cam cap 2 is provided on the bearing portion 30c.
9 is fixed by cap bolts 29a and 29b.

In this case, the cap bolt 29a arranged inside each of the bearing portions 30c (on the cylinder axis A side) is set to have a length reaching the boss portion 4f formed on the cylinder head 4. As a result, the exhaust cam carrier 30 is fixed on the cylinder head 4 at the same time when the cam cap 29 is fixed by the bolt 29a. Further, the flange 30f formed at the end of the passage boss 30d facing the position between the left and right exhaust valves and the axial end is also fixed with the fixing bolt 29.
It is fixed to a boss portion 4f formed on the cylinder head by c.

The lower part of FIGS. 6A and 6B is a state in which the cam caps of the intake and exhaust cam carriers 20 and 30 are removed, and the middle part is a cross section of the intake and exhaust cam carriers 20 and 30. The upper part shows the planar state of the bottom wall 4d of the cylinder head 4 from which the intake and exhaust cam carriers 20, 30 are removed.

Then, the cam nose 1 of the intake camshaft 16
6a, the center intake valve 11a, the right side intake valve 11c
Between the center and the right side intake valve pause mechanism 18
a and 18b are interposed, and an exhaust valve pause mechanism 19 is interposed between the cam nose 17a of the exhaust cam shaft 17 and the left exhaust valve 13a. The operation of these intake and exhaust valve suspension mechanisms 18a, 18b and 19 is controlled by a valve suspension control means (ECU) not shown. It should be noted that the left side intake valve 11b and the right exhaust valve 13b are not provided with a valve pause mechanism, and therefore the intake camshaft 1
6. The exhaust cam shaft 17 is constantly driven to open and close regardless of the operating range.

The center and right side intake valve deactivating mechanisms 18a and 18b are provided with a plunger 24 which moves forward and backward by hydraulic pressure in the center and right side lifter guide holes 20a and 20c of the intake cam carrier 20, respectively. , 21c are slidably inserted and arranged. In the left side lifter guide hole 20b, a normal lifter 21b in which the upper end opening of the cylindrical body is closed by a pad 21k with which the intake cam nose 16a is in sliding contact is slidably arranged. The upper end surface of the valve shaft 11e of the left side intake valve 11b is always in contact with the inner surface.

The center and right side lifters 21a, 21
As shown in FIGS. 10 to 12, c is the cam shaft 16 at the upper end opening of a cylindrical body having a partition wall 21d near the center in the axial direction.
The pad 21e with which the cam nose 16a is in sliding contact is fixed. A boss portion is bulged on the upper surface of the partition wall 21d, and a cylinder hole 21g is formed in the boss portion.
Is formed so as to be orthogonal to the axis of the lifter.
Both ends of this cylinder hole 21g have lifters 21a and 21c.
Is opened in an annular groove 21i formed on the outer peripheral surface of the, and the opening at one end is oil-tightly closed by a lid member 27. A slide hole 21 is formed in the partition wall 21d so as to be orthogonal to the cylinder hole 21g and coaxial with the intake valves.
f is penetratingly formed, and the slide hole 21f faces the inner surface of the pad 21e.

The transmission member 2 is provided in the slide hole 21f.
The second rod portion 22a is slidably inserted, and the lower surface central portion of the flange portion 22b formed at the lower end of the transmission member 22 is in contact with the upper end surface of the valve shaft 11e of the intake valve. Further, a biasing spring 23 is interposed between the flange portion 22b and the partition wall 21d, whereby the lifters 21a and 21c are moved to the cam nose 16a of the intake camshaft 16.
It is urged to slide into contact with.

A plunger 24 is provided in the cylinder hole 21g.
Is slidably inserted. This plunger 24
Stopper 2 provided in an annular shape on the inner surface of the cylinder hole 21g
The forward end position is regulated by 1h and the backward end position is regulated by the locking ring 21j, and the return spring 2
6 is urged to the backward end position.

An escape hole 24a having the same diameter as the slide hole 21f is formed in the plunger 24, and the escape hole 24a is coaxial with the slide hole 21f when the plunger 24 is located at the retracted end. Has become. Furthermore, the transmission surface 2 is provided on the bottom side of the plunger 24.
4b is formed flat, and this transmission surface 24b is provided with a pad 2 when the intake valve is closed (the base circle of the intake camshaft 16 is the pad 2).
Rod portion 22a of the transmission member 22 when the plunger 24 is located at the forward end in the case of sliding contact with 1e).
It opposes the upper end of the valve after leaving a predetermined valve clearance.

The exhaust valve suspension mechanism 19 has the same structure as the intake valve suspension mechanisms 18a and 18b, but the left and right exhaust lifters 31a and 31b and the exhaust cam shaft 17 are provided.
2 and 4, the cam shaft 17 is offset so as to deviate toward the cylinder shaft side. By offsetting in this way, the opening speed of the exhaust valves 13a and 13b becomes high, and a high blowdown pressure can be used for scavenging,
The scavenging efficiency can be improved. Exhaust cam shaft 1
7. Both the intake camshaft 16 rotate clockwise.

Each of the above valve stop mechanisms 18a, 18b, 1
9. The hydraulic pressure supply system to the variable valve timing mechanisms 41 and 42 is configured as shown in FIGS. That is, the oil in the oil pan 3 is sucked up by the oil pump 32, filtered by the oil filter 33, and then the oil passages 33a to 33c formed in the cylinder block 2, the cylinder head 4, and the head side cover 6a, and the switching valve 3
4 to oil passages 33h and 33n, center oil passage 3
3d or 33i, 33o and the side oil passage 33e to the center intake valve stop mechanism 18a or the right side intake valve stop mechanism 18b, or the switching valve 3
5 through the oil passages 33j and 33p and the oil passage 33g to the left exhaust valve pause mechanism 19.

Oil passage 33 of the cylinder block 2
A part of the oil a is a journal portion 44 of the crankshaft 12.
Oil passage 33b of the cylinder head 4
Part of the oil passes through the oil passage 33f formed in the cylinder head 4 and the bearing portion 20d of the cam shafts 16 and 17
To 20f, 30c, and a part of the oil in the oil passage 33c of the head side cover 6a is supplied to the variable valve timing mechanisms 41, 42 via the switching valves 45, 46.

Here, as shown in FIGS. 1 and 7, the oil passage from the oil pump 32 to the valve pause mechanism and the variable valve timing mechanism is the passage 33 in the cylinder block 2.
a, the passage 33b in the cylinder head 4 is common, but in the oil passage 33c formed in the head side cover 6a, the switching valves 34, 35 are branched into three branch portions a, b, c. , 45, 46 valve section 34
a, 35a, 45a, 46a. Each of the switching valves has a valve element inserted in each valve portion and has a solenoid 34
The communication to each passage is switched by advancing and retracting at b, 35b, 45b, 46b.

Switching valves 34, 35 for the above-mentioned valve resting mechanism
Oil passages 33h, 33 from the valve portions 34a, 35a of the
i and 33j are again the oil passages 33 in the cylinder head.
The oil passages 33d, 33e and 33g in the cam carriers 20 and 30 communicate with each other through n, 33o and 33p.
Further, the oil passages 33k and 33m from the valve portions 45a and 46a of the switching valves 45 and 46 for the variable valve timing mechanism are supported by the support shafts of the variable valve timing mechanisms 41 and 42 via the outer end support portion 6c of the head side cover 6a. It communicates with the oil introduction passage 43e of 43d.

Oil passages 33d, 33e on the intake side
In the intake cam carrier 20 parallel to the cam shaft,
Further, they are formed so as to be in contact with the center lifter guide hole 20a and the right side lifter guide hole 20c, respectively, and open to the oil groove 21i. In this case, the inclination angles θ of the center and side intake valves 11a and 11c with respect to the cylinder axis A
1, θ2, and the position L2 from the cylinder axis A in the direction perpendicular to the cam axis.
Since L1 is different, the center lifter guide hole 20
The inclination angle of the right side lifter guide hole 20c is different from that of the right side lifter guide hole 20c. As a result, by simply forming the oil passages 33d and 33e through the intake cam carrier 20 in parallel with the cam shaft, the oil passage 33d is communicated with the center lifter guide hole 20a, and the oil passage 33e is connected to the right side lifter guide hole 20c. It can be formed so as to communicate with each other.

Here, the oil passage 33e also communicates with the left side lifter guide hole 20b, and the normal lifter 21 is provided in the left side lifter guide hole 20b.
b is slidably inserted, and the above hydraulic pressure is applied to the lifter 21.
There is almost no escape from the gap between b and the guide hole 20b, and no problem occurs.

Further, the oil passage 33g on the exhaust side is formed in the exhaust cam carrier 30 in parallel with the cam shaft and in contact with the left lifter guide hole 30a to open in the oil groove 21i. This exhaust side oil passage 3
Although 3g also communicates with the right lifter guide hole 30b, the hydraulic pressure hardly escapes like the intake side.

The exhaust valve openings 10a and 10b are led out to the external connection opening 47c of the cylinder head 4 by the left and right branch ports 47a and 47b of the exhaust port 47. In this case, the partition walls 47d of the left and right branch ports 47a and 47b may be extended to the vicinity of the external connection opening 47c as shown by the chain double-dashed line in FIG. With this extension,
As will be described later, the exhaust efficiency can be improved when the left exhaust valve 13a is at rest.

The center intake valve opening 9a and the side intake valve openings 9b and 9b are the center branch port 48a of the intake port 48 and the left and right side branch ports 48b and 48, respectively.
It is led out to the external connection opening 48d of the cylinder head 4 by c. Here, the right picture wall 48f on the right side branch port 48c side is the left picture wall 48e on the left side branch port 48b side.
It has been extended far upstream. This is to realize stratified combustion, as will be described later.

A fuel injection valve 50 is arranged on the top wall portion of the intake manifold 49 connected to the external connection opening 48d. When viewed in the cylinder axis direction (see FIG. 8), the fuel injection valve 50 is located substantially on the extension line of the left picture wall 48 e, and the injection nozzle 50 a has the injection port 50 a.
The fuel is directed to inject fuel into the center intake valve opening 9a and the left side intake valve opening 9b through an injection hole 48f formed in the top wall of No. 8.

Next, the function and effect of the first embodiment will be described. In the device of the present embodiment, the variable valve timing mechanism 41,
The opening / closing timing of the intake valve and the exhaust valve is controlled by 42, and the valve pause mechanism 18a, 18b, 19 controls the valve pause of the intake valve and the exhaust valve.

First, in the variable valve timing mechanism 41 or 42, the switching valve 45 or 46 applies hydraulic pressure to the piston 4
3C, the piston 43c moves to the left in FIG. 7, and the timing gear 36a,
Or 36b and the phase of the intake cam shaft 16 or the exhaust cam shaft 17 change, and the intake valves 11a to 11c or the exhaust valve 13 are changed.
The opening / closing timing of a and 13b changes.

Further, in the valve deactivating mechanism 18a, 18b, when the switching valve 34 is in the deactivating position shown by the solid line in FIG. 13, the hydraulic pressure is transmitted via the oil passages 33d, 33e to the center intake valve deactivating mechanism 18a, and It is supplied to the right side intake valve stop mechanism 18b. Then, as shown in FIG. 10, the plunger 24 moves forward by the action of hydraulic pressure to close the slide hole 21f, and the transmission surface 2 of the plunger 24 is closed.
4b faces the upper end surface of the transmission rod 22a of the transmission member 22. When the center and the right side lifters 21a and 21c are pushed down by the rotation of the cam shaft 16, the operation is transmitted to the center and the right side intake valves 11a and 11c through the plunger 24 and the transmission member 22, and the intake valves 11a and 11c.
c performs the opening / closing operation as usual.

Further, in the valve resting mechanism 19, the switching valve 3
5 is in the rest release position shown by the solid line in FIG. 5, hydraulic pressure is transmitted through the oil passage 33g to the right exhaust valve rest mechanism 1
9 to the left exhaust valve 13a in the same manner as described above.
Opens and closes normally. The left side intake valve 1
1b and the right exhaust valve 13b always open and close.

Then, the switching valve 3 for switching the valve pause.
When 4 is switched to the rest position shown by the broken line in FIG. 5, the hydraulic pressure in the oil passages 33d and 33e decreases, and the plunger 24 is returned to the retracted end position by the return spring 26, as shown in FIG. The escape hole 24a of 24 corresponds to the slide hole 21f, that is, the transmission rod 22a. Center and right side lifter 2 by rotation of cam shaft 16
When 1a and 21c are pushed down, the transmission rod 22a relatively enters into the escape hole 24a as shown in FIG. 12, and the lowering operation of the lifter is transmitted to the center and right side intake valves 11a and 11c. Therefore, both the intake valves 11a and 11c are deactivated and are held in the closed position.

Here, if the intake valves 11a and 11c are completely closed in the valve resting operation, the fuel accumulated in the center and right side branch ports 48a and 48c may be carbonized and adhere to the inner surfaces of the ports. In the present embodiment, even when the valve is at rest, when the lifters 21a and 21c descend to the maximum lift position, the pad 21
The lower surface of e slightly pushes down the transmission rod 22a, so that the intake valves 11a and 11c are slightly opened.

Further, in the valve pause mechanism 19, the switching valve 3
When No. 5 is switched to the rest position shown by the broken line in FIG. 5, the oil pressure in the oil passage 33g decreases, and the left exhaust valve 13a enters the valve rest state and is held in the closed position as in the above case. The left exhaust valve 13a may be slightly opened when the valve is stopped.

In a small intake air operation range such as low speed rotation or low load operation, the switching signals from the ECU cause the switching valves 34 and 35 to switch to rest positions shown by broken lines in FIG. As a result, the oil passages 33d, 33
As the hydraulic pressures of e and 33g decrease and the plunger 24 retracts, as shown in FIG. 9A, the center, the right side intake valves 11a and 11c, and the left exhaust valve 13a are in the valve resting state, and the left side intake valve Only 11b and the right exhaust valve 13b perform the opening / closing operation.

As a result, the intake air has a diameter Dis1 and a small diameter, and the distance from the cylinder axis A in the direction perpendicular to the cam axis is small, ie, L1 and is closer to the cylinder axis side. Concentrated from the intake valve opening 9b and flows into the cylinder. As a result, the actual intake passage area becomes narrower, the inflow speed into the cylinder is faster even with a small amount of intake air, and the inflow direction becomes clear, and in-cylinder flow, especially swirl, occurs, and the combustion condition becomes good. As a result, the stability of lean air-fuel ratio combustion can be improved.

Further, in this case, the left side intake valve 11b,
Since only the right exhaust valve 13b oppositely arranged with the ignition plug 25 (cylinder axis A) interposed therebetween is opened and closed, the intake air that has flowed in through the left side intake valve opening 9b is, after combustion, sandwiched the ignition plug 25. The exhaust gas is discharged from the right exhaust valve opening 10b at the opposite position, that is, the flow of the exhaust gas passes through the center of the combustion chamber, so that the exhaust gas exhaust efficiency is improved. By the way, if only one intake valve and one exhaust valve are opened and closed in this way, the left side intake valve 1
When the 1b and the left exhaust valve 13a are opened / closed, stagnation of the exhaust gas occurs in the combustion chamber, which may reduce the exhaust efficiency.

In order to discharge the exhaust gas more reliably, it is effective to extend the partition wall 47d of the exhaust port 47 to the vicinity of the external connection opening 47c as shown by the chain double-dashed line in FIG. In this case, the flow of the above-mentioned exhaust gas becomes smoother, and the exhaust efficiency improves. By the way, when the wall 47d is not extended, when only the right exhaust valve 13b operates, the right exhaust branch port 4
The passage area of 7b substantially expands substantially, and stagnation of exhaust gas occurs on the side of the left exhaust branch port 47a, so there is a concern that exhaust efficiency will decrease.

In the medium intake air amount operation range such as the medium speed rotation or the medium load operation, the switching valve 34 is held at the valve rest position (the broken line position in FIG. 5) with respect to the oil passage 33d by the switching signal from the ECU. The oil passage 33e is switched to the rest release position (solid line position in FIG. 5), and the switching valve 35 is switched to the rest release position shown in solid line in FIG. As a result, as shown in FIG. 9B, only the center intake valve 11a is in the valve resting state,
The left and right side intake valves 11b and 11c and the left and right exhaust valves 13a and 13b are opened and closed.

As a result, the intake air has a small distance L1 from the cylinder axis A in the direction perpendicular to the cam axis, and is close to the cylinder axis side, and has two left and right side intake valve openings 9b and 9c located on both sides in the cam axis direction. Flows into the cylinder from. As a result, the intake air flow into the cylinder is more oriented along the cylinder axis as a result of the swirl components canceling each other out,
In-cylinder flow, especially tumble, is reliably generated and the combustion state is improved, and as a result, the stability of lean air-fuel ratio combustion can be improved. In this case, in the present embodiment, the center intake valve 11a has a large diameter and the left and right side intake valves 11b and 11c are provided.
From this point, the distance L1 in the direction perpendicular to the cam shaft becomes smaller, that is, the left and right side intake valve openings 9b, 9c are closer to the cylinder axis A side and further outward in the cam axis direction. As a result, the cylinder is positioned more reliably as a result.

In a large intake air operation range such as high speed rotation or high load operation, the switching signal from the ECU causes the switching valve 34 to switch to the rest release position for the oil passage 33d as well. The valve rest operation is released, and all intake valves and exhaust valves open and close.

As a result, the intake air flows into the cylinder through the center, left, and right side intake valve openings 9a to 9c. In this case, for example, when a conventional intake control valve is provided in the intake port 47. Since there is no such a flow path resistance, the maximum intake amount can be increased.

Further, in this embodiment, since the right picture wall 48f extends toward the fuel injection valve 50 side and the fuel injection valve 50 is arranged close to the left picture wall 48e side, it is used for the center and left side intake valves. The intake air from the openings 9a and 9b is a mixture of fuel and air, whereas the intake air from the right side intake valve opening 9c is a single air containing almost no fuel. As a result, the air-fuel mixture containing the fuel and the air simple substance flow in layers in the combustion chamber, and so-called layered combustion can be realized.

FIG. 22 is an engine speed-torque characteristic curve for explaining the effect of improving the torque by the valve resting operation of the apparatus of this embodiment. In the figure, the curves A, B and C are the above small, medium and Fig. 3 conceptually shows torque characteristics in a large intake air operation range.

In this embodiment, an intake cam carrier 20 and an exhaust cam carrier 30 which are attachable to and detachable from the cylinder head 4 are provided as a structure for realizing the above-mentioned valve resting operation.
By adopting the structure in which the valve suspension mechanism is incorporated in each of the carriers 20 and 30, the structure of the hydraulic pressure supply system to the valve suspension mechanism can be simplified. That is, each cam carrier 20,
Since 30 is a separate body, the oil passages 33d, 33e, 3
Easy to drill 3g. By the way, if a structure in which a valve pause mechanism is incorporated in a portion integrated with the cylinder head 4 is adopted, the oil passage may penetrate the outer wall (cam chamber forming wall) of the end of the cylinder head 4 in the cam shaft direction. In addition, the structure of the hydraulic pressure supply system becomes complicated by providing a branch passage in the direction perpendicular to the cam shaft, and the handleability deteriorates due to the need to directly drill a large and heavy cylinder head.

In this embodiment, the center lifter guide hole 20
Since a and the right side lifter guide hole 20c are arranged with different inclination angles and shifted in the direction perpendicular to the cam shaft, the oil passages 33d and 33e are arranged parallel to the cam shaft 16 and on the outer periphery of each guide hole 20a, 20c. The hydraulic pressure can be supplied to the center intake valve suspension mechanism 18a and the right side intake valve suspension mechanism 18b independently and separately only by opening the valve so that they come into contact with each other. By the way, when both guide holes 20a and 20c are arranged at the same inclination angle, each guide hole 20a, 20c
An oil passage is provided at a position away from c, and a branch passage is provided in a direction perpendicular to the cam axis from the oil passage, which complicates the structure.

In this embodiment, the oil passage 33c is constructed so as to pass through the inside of the head side cover 6a, and the oil passage is provided in the head side cover 6a with an oil passage for the valve stopping mechanism and an oil passage for the variable valve timing mechanism. Since it branched to, switching valve 3 for valve pause mechanism
4, 35 and switching valve 4 for variable valve timing mechanism
It is possible to arrange all 5, 46 on the head side cover 6a. Further, in this case, the oil passage 33f for supplying the lubricating oil to the bearings of the cam shafts 16 and 17 is formed so as to pass through the inside of the cylinder head 4. As a result, for an engine that does not have a valve pause mechanism or the like, it suffices to change the head side cover to a specification in which the oil passage 33c and the like are not formed, and it is easy to share parts.

In this embodiment, the switching valves 34, 3 are utilized by utilizing the dead space below the portion of the head side cover 6a for accommodating the variable valve timing mechanisms 41, 42.
5, 45, and 46 can be arranged, and an increase in the size of the engine due to the arrangement of the switching valve can be avoided.

14 and 15 show claims 1, 2, 7, and 8.
FIG. 10 is a diagram for explaining an engine valve deactivation device according to an embodiment (second embodiment) of the present invention, in which the same reference numerals as those in FIGS. 8 and 9 denote the same or corresponding portions.

In the second embodiment, the valve diameter Dic of the center intake valve 11a, the valve diameters Dis1 and Dis2 of the left and right side intake valves 11b and 11c, and the valve diameters De1 and De2 of the left and right exhaust valves 13a and 13b. And Dis1 = Dis2> De1
= De2> Dic. That is, the center intake valve 11a has the smallest diameter.

Further, the distance L2 in the direction perpendicular to the cam axis from the cylinder axis A of the center intake valve 11a and the left and right side intake valves 11b,
The distance L2 from the cylinder axis A of the cylinder 11c in the direction perpendicular to the cam axis is
The relationship of L2> L1 is set.

Further, the fuel injection valve 50 is arranged on the axis of the intake port 48, and the left drawing wall 48 of the intake port 48.
e, the right picture wall 48f is set to have the same length. In this case, the upstream ends of the left and right drawing walls 48e, 48f are located at positions distant from the fuel injection valve 50, so that the fuel from the fuel injection valve 50 is not limited to the center intake valve opening 9a. Injection is supplied toward the left and right side intake valve openings 9b and 9c.

The valve stop mechanism on the intake side is constructed so that either one or both of the left and right side intake valves 11b and 11c can be stopped at the same time. Further, the exhaust-side valve deactivating mechanism is configured to deactivate the left exhaust valve 13a. The center intake valve 1
1b, the right exhaust valve 13b is not provided with a pause mechanism, and therefore both valves 11b, 13b are always opened and closed.

Here, the left and right side intake valves 11b, 1 are
A separate and independent oil passage is required in order to make either one of 1c restable. In order to make these oil passages independent, two oil passages are formed in the intake cam carrier 20 at positions apart from the left and right side lifter guide holes 20b and 20c in parallel with the cam shaft 16, and the respective oil passages are formed. A branched oil passage may be formed to connect the passage and the lifter guide holes 20b and 20c.

In the device of the second embodiment, when the intake air amount is small,
As shown in FIG. 15A, the left and right side intake valves 11
b, 11c and the left exhaust valve 13a are stopped, and only the center intake valve 11a and the right exhaust valve 13b are opened and closed. Therefore, the intake air flows into the cylinder only through the opening 9a for the center intake valve having the smallest diameter, and the inflow speed is increased by the smaller inflow area. Further, the intake air flows into the cylinder through the center intake valve opening 9a, which exists only one on the outermost side from the cylinder axis A, and the directionality is not disturbed by the flow in the opposite direction. As a result, in-cylinder flow is reliably generated, and lean air-fuel ratio combustion is stabilized.

Further, in this case, the intake air mixed with fuel from the fuel injection valve located at the center of the intake port 48 is located at the center intake valve opening 9a located so as to face the cylinder axis A.
From the above, the air-fuel mixture directly flows into the spark plug 25 also located near the cylinder axis A, so that the air-fuel mixture concentrates around the spark plug 25, thereby stabilizing the lean air-fuel ratio combustion. Further, in this embodiment, the center intake valve opening 9a is set to have the smallest diameter, so that the spark plug 25
Can be arranged closer to the center intake valve opening 9a side, and the combustibility can be improved also from this point.

At the time of the medium intake amount, as shown in FIG. 15 (b), the deactivating operation of the right side intake valve 11c and the left exhaust valve 13a is released, and only the left side intake valve 11b is deactivated. Therefore, intake air flows in through the center intake valve opening 9a and the right side intake valve opening 9c, and an oblique swirl is generated that combines the flow in the cylinder axial direction (tumble) and the flow along the cylinder inner surface (swirl). This stabilizes the lean air-fuel ratio combustion.

Further, when the intake air amount is large, as shown in FIG. 15 (c), the center intake valves 11a-1 and the left and right intake valves 11a-1
Since all of 1c operate, the inflow area becomes large, and there is no inflow passage resistance, so the maximum intake amount increases.

Furthermore, in this embodiment, the center intake valve 11a has the smallest diameter, so that the clearance of the top surface of the piston 7 for avoiding the interference with the valve head 11d of the center intake valve 11a can be reduced. By the way, since the center intake valve is located at the lowest position in the combustion chamber, it easily interferes with the piston top surface.Therefore, in the conventional engine, a large relief is formed in the part of the piston top surface facing the center intake valve. ,
Although there was a problem that the strength of the top of the piston was reduced due to this escape, this problem can be solved in this embodiment.

16 and 17 show claims 1, 4, 7, and 10.
FIG. 10 is a diagram for explaining an engine intake device according to an embodiment (third embodiment) of the present invention, in which the same reference numerals as those in FIGS. 8 and 9 denote the same or corresponding portions.

In the third embodiment, the valve diameter Dic of the center intake valve 11a, the valve diameters Dis1 and Dis2 of the left and right side intake valves 11b and 11c, and the valve diameters De1 and De2 of the left and right exhaust valves 13a and 13b. Means that Dic = Dis2> De1 =
The relationship is set to De2> Dis1. That is, the left side intake valve opening 9b has the smallest diameter.

Further, the distance L3 of the center intake valve 11a from the cylinder axis A in the direction perpendicular to the cam axis, the distance L2 of the right side intake valve 11c in the direction perpendicular to the cam axis, and the distance L1 of the left side intake valve 11b in the direction perpendicular to the cam axis. And L3>L2> L1. That is, the distance is different for all three intake valves.

Further, the fuel injection valve 50 is arranged on the extension line of the left wall 48e of the intake port 48, and the intake port 4
The left picture wall 48e and the right picture wall 48f of 8 are set to the same length. In this case, the upstream ends of the left and right picture walls 48e, 48f are located at positions distant from the fuel injection valve 50, whereby the fuel from the fuel injection valve 50 is mainly discharged from the center intake valve opening 9a and the center intake valve opening 9a. Left side intake valve opening 9b
Is jetted and supplied toward.

The valve stop mechanism on the intake side is constructed so that either the center intake valve 11a or the right side intake valve 11c, or both, can be stopped at the same time.
Further, the exhaust-side valve deactivating mechanism is configured to deactivate the left exhaust valve 13a. The center intake valve 11b and the right exhaust valve 13b are not provided with a pause mechanism, so that the valves 11b and 13b are always opened and closed.

In the device of the third embodiment, when the intake air amount is small,
As shown in FIG. 17A, the center intake valve 11a, the right side intake valve 11c, and the left exhaust valve 13a are stopped, and only the left side intake valve 11b and the right exhaust valve 13b are opened and closed. Therefore, the intake air flows into the cylinder only through the left-side intake valve opening 9b having the smallest diameter, and the inflow speed increases by the smaller inflow area. Further, the intake air may flow into the cylinder 9b for the left side intake valve, which is located at a position closest to the cylinder axis A and outward in the cam axis direction, and the directionality may be disturbed by the flow in the opposite direction. Absent. As a result, in-cylinder flow, particularly swirl, is reliably generated, and lean air-fuel ratio combustion is stabilized.

At the time of the medium intake amount, as shown in FIG. 17B, the deactivating operation of the center intake valve 11a and the left exhaust valve 13a is released, and only the right side intake valve 11b is deactivated.
Therefore, intake air flows in through the center intake valve opening 9a and the left side intake valve opening 9b, and an oblique swirl is generated that combines the flow in the cylinder axial direction (tumble) and the flow along the inner surface of the cylinder (swirl). This stabilizes the lean air-fuel ratio combustion.

Further, at the time of a large intake amount, as shown in FIG. 17 (c), the center and left and right side intake valves 11a-1
Since all of 1c operate, the inflow area becomes large, and there is no inflow passage resistance, so the maximum intake amount increases.

FIG. 18 is a view for explaining one embodiment (fourth embodiment) of the invention of claims 1 and 6, and in FIG.
The same reference numerals as in FIG. In the fourth embodiment, the relationship between the valve diameters of the intake valves and the exhaust valves, the position of the fuel injection valve 50, and the shapes of the left and right drawing walls 48e and 48f are set in the same manner as shown in FIG. . On the other hand, the valve deactivation mechanism on the intake side is capable of deactivating only the center intake valve 11a, and the valve deactivation mechanism on the exhaust side is the right exhaust valve 13b.
Only the rest can be paused.

In the fourth embodiment, when the intake air amount is small, as shown in FIG.
As shown in FIG. 8 (a), the center intake valve 11a and the right exhaust valve 13b are at rest, and intake is performed by the left and right side intake valve openings 9
The exhaust gas flows out from the left exhaust valve 13a. In this way, intake air flows into the cylinder through the left and right side intake valve openings 9b and 9c located on the left and right sides of the cylinder axis, so that tumble is likely to occur.

At the time of the medium intake amount, as shown in FIG. 18 (b), the center intake valve 11a continues to be stopped and the right exhaust valve 13b is released. Therefore, since a relatively large amount of intake air flows in through the left and right side intake valve openings 9b and 9c as in the case of the small intake air amount, the tumble becomes more reliable. Further, in this case, since both the exhaust valves operate, exhaust gas is surely discharged.

Furthermore, when the intake air amount is high, all intake valves operate, so that a sufficient maximum intake air amount can be secured.

Here, in the above-mentioned first to fourth embodiments, the valve is stopped in the state where the hydraulic pressure is not supplied, and the valve stop is released when the hydraulic pressure is supplied. The valve may be stopped, and the valve may be released when the hydraulic pressure is not supplied. With this configuration, it is possible to provide the valve resting mechanism for all the valves, and the degree of freedom in design is expanded.

That is, if the valve suspension is released without hydraulic pressure, all the valves will operate until the hydraulic pressure is generated at the time of engine start, regardless of the presence or absence of the valve suspension mechanism. Even if the valve is provided with a valve pause mechanism, it can be started. By the way, if, as in the case of the above-mentioned embodiment, the valve pause is released by the presence of hydraulic pressure, if all the valves are provided with the valve pause mechanism, the engine cannot be started, and at least one intake valve is eventually closed. Inevitably, the exhaust valve has no valve pause mechanism. In the above embodiment, at least one of the intake valve and the exhaust valve is not provided with the valve pause mechanism.

FIG. 19 is a view for explaining one embodiment (fifth embodiment) of the invention of claims 1 and 5, and FIG.
The same reference numerals as in FIG. The present embodiment is an example in which the valve suspension is released without hydraulic pressure and all the intake valves 11a to 11c are provided with a suspension enabling mechanism.

In the fifth embodiment, the relationship between the valve diameters of the intake valves and the exhaust valves, the position of the fuel injection valve 50, the left and right wall 48.
The shapes of e and 48f are set similarly to those shown in FIG. On the other hand, the valve stop mechanism on the intake side can switch between the center intake valve 11a and one of the left and right side intake valves 11b and 11c to be stopped. Further, the exhaust-side valve deactivation mechanism can deactivate only the right exhaust valve 13b.

In the fifth embodiment, since no hydraulic pressure is generated at the time of starting, all the valve resting mechanisms are released, so that all the valves open and close and can be started without any trouble. When the intake air amount is small, as shown in FIG. 19A, the left and right side intake valves 11b and 11c and the right exhaust valve 13b are deactivated, and the center intake valve 11a is deactivated. Therefore, intake air flows in through the center intake valve opening 9a, and exhaust gas flows out through the left exhaust valve 13a. As described above, since the intake air flows in through the center intake valve opening 9a, which has the smallest diameter and is located only one position away from the cylinder axis A, the inflow speed is high, the directionality is clear, and the in-cylinder flow is It occurs reliably and the lean air-fuel ratio combustion is stabilized.

Further, in this case, the air-fuel mixture is concentrated on the spark plug 25, which stabilizes the lean air-fuel ratio combustion. Further, since the center intake valve opening 9a is set to have the smallest diameter, the spark plug 25 can be arranged closer to the center intake valve opening 9a side, and the combustibility can be improved also from this point.

Further, at the time of the medium intake amount, as shown in FIG. 19 (b), the center intake valve 11a is deactivated and the left and right side intake valves 11b, 11c and the right exhaust valve 13b are deactivated. In this switching, first, the left and right side intake valves 11a are operated with the center intake valve 11a being operated.
Release the rest of b and 11c, and then the center intake valve 11
It is desirable to pause a. This alleviates the shock at the time of switching.

By releasing the suspension of the left and right side intake valves 11b and 11c, a relatively large amount of intake air flows in through the left and right side intake valve openings 9b and 9c as in the case of the small intake air amount. Will be more certain. Also in this case,
Since both exhaust valves are activated, exhaust gas is surely discharged.

Further, when the intake air amount is high, all intake valves are operated, so that a sufficient maximum intake air amount can be secured.

FIG. 20 shows a modification of the valve suspension control in the first embodiment. In this modification, the same pause control as in the first embodiment is performed when the intake air amount is small (see FIG. 10A), but the control is different when the intake air amount is medium and when the intake air amount is large. That is, when the medium intake air amount is set, as shown in FIG.
3a is paused, and the large intake air amount operating range is divided into an operating region with a relatively small intake amount and an operating region with a large intake amount. In the operating region with a relatively small intake amount, as shown in FIG. The center intake valve 11a releases the pause, and the left exhaust valve 13a continues the pause as in the case of the medium intake amount. Then, all valves are operated in the operating range where the intake air amount is large.

With this structure, only one exhaust valve operates in the first half of the large intake amount operation range, so that the equivalent pipe length of the exhaust pipe in the large intake amount operation range becomes long. As indicated by a two-dot chain line torque curve C ′ at 22, the torque can be further improved in the high speed rotation range (large intake air amount operation range).

FIG. 21 shows a modification of the valve stop control in the second embodiment. In this modified example, the same pause control as that of the second embodiment is performed at the time of a small intake amount (see (a) of the same figure) and at the time of a large intake amount (see (c) of the same figure), but at the time of a medium intake amount. Control is different. That is, the medium intake air amount operation region is divided into an operation region in which the intake air amount is relatively small and an operation amount in which the intake air amount is large. In the operation region in which the intake air amount is small, as shown in FIG.
a, the right side intake valve 11c, and the right exhaust valve 13b are operated, and the left exhaust valve 13a continues to be inactive. Then, in the operating range in which the intake air amount is relatively large, the left exhaust valve 13a is also activated as in the second embodiment.

With this configuration, only one exhaust valve operates in the first half of the medium intake air amount operation range, so that the equivalent pipe length in the medium intake air amount operation region of the exhaust pipe becomes long, and As indicated by a two-dot chain line torque curve B ′ at 22, the torque can be further improved in the medium speed rotation range (medium intake air amount operation range).

In each of the above embodiments, the case of a five-valve engine having three intake valves and two exhaust valves has been described. However, the present invention has two or four intake valves near the cylinder axis side. The present invention can also be applied to the case where the cylinders are separately arranged on the side opposite to the cylinder side.

Further, in each of the above embodiments, the valve lift curves of the intake valve and the exhaust valve can be set as follows according to the valve diameter, and the above-described valve suspension control can be performed.

For example, the maximum lift of the small diameter valve is set smaller than the maximum lift of the large diameter valve. As a result, the following effects can be obtained in addition to the effects obtained by adopting the above-mentioned small-diameter valve and performing the valve stop control. That is, since the lifter diameter for the small diameter valve can be reduced by the amount by which the maximum lift amount of the small diameter valve is reduced, the lifter diameter for the large diameter valve can be increased in space and the maximum lift of the large diameter valve can be increased. As a result, the ratio (dynamic range) of the flow rate when the large diameter valve is stopped and the flow rate when the small diameter valve is stopped can be increased. As a result, it is possible to further strengthen the in-cylinder flow when the intake air amount is small, and to increase the maximum intake air amount when the intake air amount is large. Further, it is possible to avoid waste of excessive lift amount despite the small diameter valve. That is, in the case of a small diameter valve, even if the lift is larger than necessary, it is not effective in increasing the flow rate.

Further, by utilizing the above-mentioned variable valve timing mechanism or by appropriately setting the cam nose shape, the opening / closing timing of the valve opening / closing in the low speed rotation range of the engine can be set such that the exhaust valve and the intake valve overlap. Make it smaller. This can be realized by advancing the closing timing of the exhaust valve and retarding the opening timing of the intake valve. By thus reducing the overlap in the low speed rotation range, combustion in the low speed rotation range can be improved, idle rotation can be stabilized, and low speed torque can be increased.

Furthermore, in each of the above-described embodiments, various operational effects are obtained by changing the valve diameter, but the valve diameter is not changed, but the lift amount and the seat angle α in FIG. 23 are changed. The effect of can be obtained. For example, as shown in FIG. 23, the valve diameters are the same in each of the above-described embodiments, and the valve (intake valve) arranged in a portion having a small diameter has a small lift and the seat angle α is reduced to a large value. The valve (intake valve) arranged at the portion having the diameter is set to a large lift and the seat angle α is increased. By combining this with the valve stop control of the above embodiment, the same effect as that of the above embodiment can be obtained for the following reason.

The present inventors have confirmed by experiments that the effective opening area and hence the flow rate are proportional to H cos α, where H is the lift amount. That is, as shown in FIG. 24, when α is small (see the curve A), the flow rate suddenly increases at the initial opening of the valve (see FIG. 23B when the lift is low), but the large lift Even if it becomes, the flow resistance does not increase any more because the bending resistance is large (Fig. 23).
(C)). On the other hand, when α is large (see the curve B), the increase in the opening area is slow in the initial stage of opening the valve, and thus the increase in the flow rate is relatively slow (see FIG. 23 (e)), but the bending resistance increases when the lift is large. The flow rate is greatly increased by a small amount (see FIG. 23 (f)).

As described above, making α small and small lift is equivalent to a small diameter valve, and making α large and large lift is equivalent to a large diameter valve, and can be replaced as described above. In addition, in this case, since the valve diameters are all the same, it is possible to deal with it only by changing the seat angle α, and the manufacturing is easy. In addition, the valve with a small seat angle α uses the small lift portion, and the valve with a large seat angle α uses the large lift portion. It is efficient.

[0113]

According to the first aspect of the present invention, the valve pausing mechanism is arranged in the cam carrier separate from the cylinder head, and the oil passage to the valve pausing mechanism is formed in the cam carrier. The passage can be easily machined. Particularly, since the invention of claim 2 is applied to the parallel multi-cylinder engine, the oil passage can be further easily machined.

According to the third aspect of the present invention, a part of the valve lifter and at least a part of the rest are different in inclination angle with respect to the cylinder axis, and the oil passage is formed for each valve lifter having a different inclination angle. There is an effect that the oil passage structure can be simplified when the valve is independently stopped.

According to the invention of claim 4, the oil passage is formed so as to be in parallel with the cam shaft and in contact with the lifter guide hole for each valve lifter having a different inclination angle. This has the effect of simplifying the structure when independently suspended.

According to the fifth aspect of the present invention, when one center intake valve and two first and second side intake valves are provided, the center valve lifter is located closer to the non-cylinder shaft side,
Since the inclination angle of each valve lifter with respect to the cylinder axis is set so that the side valve lifter is located closer to the cylinder axis side, the center valve lifter oil passage should be in contact with the outer peripheral surface of the center lifter guide hole on the opposite cylinder axis side. The oil passage for the valve lifter can be formed so as to be in contact with the outer peripheral surface of the side lifter guide hole on the cylinder shaft side, and there is an effect that the oil passage can be simplified when the center intake valve and the side intake valve can be independently suspended. .

According to the invention of claim 6, the oil passage can be formed so as to be in contact with both lifter guide holes even when only one of the first and second side intake valves is provided with the valve stopping mechanism. There is an effect that the oil passage structure can be simplified because the branch passage in the direction perpendicular to the cam axis is unnecessary.

[Brief description of drawings]

FIG. 1 is a front view of a four-cycle engine equipped with a valve deactivation device according to a first embodiment of the present invention.

FIG. 2 is a sectional front view showing a right side intake valve and a right exhaust valve of the engine of the first embodiment.

FIG. 3 is a sectional front view showing a center intake valve portion of the engine of the first embodiment.

FIG. 4 is a sectional front view showing a left side intake valve and a left exhaust valve portion of the engine of the first embodiment.

FIG. 5 is a plan view showing a state in which the intake and exhaust cam carriers of the cylinder head of the first embodiment engine are removed.

FIG. 6 is a partial cross-sectional plan view of an intake / exhaust cam carrier of the first embodiment engine.

FIG. 7 is a sectional rear view showing an oil system of the engine of the first embodiment.

FIG. 8 is a schematic cross-sectional plan view showing an intake valve opening and an exhaust valve opening of the engine of the first embodiment.

FIG. 9 is a schematic diagram for explaining the operation of the engine of the first embodiment.

FIG. 10 is a cross-sectional view showing a valve pausing mechanism portion of the engine of the first embodiment.

FIG. 11 is a cross-sectional view showing a valve pausing mechanism portion of the engine of the first embodiment.

FIG. 12 is a cross-sectional view showing a valve pausing mechanism portion of the engine of the first embodiment.

FIG. 13 is an oil system diagram of the engine of the first embodiment.

FIG. 14 is a schematic cross-sectional plan view showing an intake valve opening and an exhaust valve opening of a four-cycle engine according to a second embodiment of the present invention.

FIG. 15 is a schematic diagram for explaining the operation of the engine of the second embodiment.

FIG. 16 is a schematic cross-sectional plan view showing an intake valve opening and an exhaust valve opening of a four-cycle engine according to a third embodiment of the present invention.

FIG. 17 is a schematic diagram for explaining the operation of the engine of the third embodiment.

FIG. 18 is a schematic diagram for explaining the operation of the 4-cycle engine according to the fourth embodiment of the present invention.

FIG. 19 is a schematic diagram for explaining the operation of the 4-cycle engine according to the fifth embodiment of the present invention.

FIG. 20 is a schematic diagram for explaining a modification of the valve deactivation control operation of the engine of the first embodiment.

FIG. 21 is a schematic diagram for explaining a modified example of the valve stop control operation of the second embodiment engine.

FIG. 22 is an engine speed-torque characteristic diagram for explaining the effect of the first embodiment engine.

FIG. 23 is a schematic diagram showing a development example of each of the embodiments.

FIG. 24 is an engine speed-flow rate characteristic diagram showing the effect of the above-described developed example.

[Explanation of symbols]

1 engine 4 cylinder head 11a center intake valve 11b, 11c left (first), right (second) side intake valve 16, 17 intake, exhaust camshaft 18a center intake valve pause mechanism 18b left (first) side intake valve pause Mechanism 19 Exhaust valve stop mechanism 20,30 Intake, exhaust cam carriers 20a, 20b, 20c Center, left, right side intake lifter guide holes 21a, 21b, 21c Center, left, right side intake lifters 30a, 30b Left, right exhaust lifter Guide holes 31a, 31b Left and right exhaust lifters 33d, 33e Intake oil passage 33g Exhaust oil passage A Cylinder axis θ1, θ2 Inclination angle

Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display area F02D 13/02 E

Claims (6)

[Claims] 1. A valve carrier for an engine, wherein at least a part of a plurality of valves is held in a closed position in accordance with an engine operating state, a cam carrier that pivotally supports a cam shaft is separable from a cylinder head. Then, a lifter guide hole is formed in the cam carrier, and a valve lifter for transmitting the operation of the cam shaft to the valve shaft is slidably inserted and arranged in the lifter guide hole, and a hydraulically driven valve pause mechanism is installed in the valve lifter. A valve pausing device for a four-cycle engine, wherein an oil passage for arranging and supplying an oil pressure to the valve pausing mechanism is formed in the cam carrier. 2. The engine according to claim 1, wherein the engine is a parallel multi-cylinder engine, the cam carrier is an intake or exhaust cam carrier for all cylinders formed integrally, and the oil passage is intake or exhaust for all cylinders. A valve deactivation device for a four-cycle engine, wherein the oil passage is formed in a straight line. 3. A valve deactivating device for an engine, wherein at least a part of a plurality of valves is held in a closed position according to an engine operating state, a lifter guide hole is formed in a cylinder head, and a cam is provided in the lifter guide hole. A valve lifter for transmitting the movement of the shaft to the valve shaft is slidably inserted and arranged, and a hydraulically driven valve pause mechanism is arranged in the valve lifter.
An inclination angle formed by a cylinder axis of a part of the plurality of valve lifters is different from an inclination angle of at least a part of the remaining valve lifters, and an oil passage for supplying a hydraulic pressure to the valve pause mechanism has a different inclination angle. A valve deactivation device for a four-cycle engine, characterized in that it is formed for each valve lifter. 4. The valve for a four-cycle engine according to claim 1, wherein the oil passage is formed in parallel with the cam shaft and in contact with the lifter guide hole. Rest device. 5. A center intake valve located in the center in the cam axis direction, and first and second side intake valves located on both sides of the center intake valve in the cam axis direction according to any one of claims 1 to 4. The center intake valve lifter for the center intake valve is located closer to the anti-cylinder shaft side, and the tilt angle of each valve lifter with respect to the cylinder shaft is set so that the first and second side intake valve side valve lifters are located closer to the cylinder shaft side. Has been done,
The oil passage for the center valve lifter is formed so as to contact the outer peripheral surface of the center lifter guide hole on the side opposite to the cylinder axis, and the oil passage for the side valve lifter is formed so as to contact the outer peripheral surface of the side lifter guide hole on the cylinder axis side. Characteristic 4-cycle engine valve deactivation device. 6. The valve lifter having a built-in valve stopping mechanism is slidably disposed in the second intake valve lifter guide hole, and the first intake valve lifter guide hole is disposed in the first intake valve lifter guide hole. A bottomed tubular valve lifter without a built-in valve pause mechanism is slidably arranged, and the oil passage is in contact with both the first and second side intake valve lifter guide holes. 4 cycle engine valve deactivation device.