JPH07208182A - Intake control device of engine - Google Patents

Abstract

PURPOSE:To provide the intake control device of an engine in which the form of the intake passage is not complicated,and the suction resistance at the full opening condition is not increased, and even in case of a multiple cylinder engine, an excessive mechanical process is not necessary for installing a valve body. CONSTITUTION:A valve body 29 is installed to the outer wall surface of a cylinder head 5, an invalve intake passage 29a is formed to the valve body 29 at each cylinder, a needle 23 is installed to the valve body 29, and a valve 30 having a cutting surface 30a is formed to the needle 23 at each cylinder. The needle 23 is held rotatable between thc full opening position where the valve 30 is sunk in the bottom wall of the invalve intake passage 29a, and the full closed position where the valve 30 reduces the suction passage area to make the suction air flow biased to the ceiling wall 29c of the intake passage 29a. A fuel injection valve 24 is installed to the ceiling wall 29c of the invalve intake passage 29a of the valve body 29.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an intake control device for an engine provided with an intake control valve for variably controlling a passage area in an intake passage.

[0002]

2. Description of the Related Art In order to improve a combustion state of an engine, particularly in a low speed rotation region, it is effective to generate a so-called tumble in the intake air flow introduced into a cylinder, the longitudinal vortex having a directionality in the cylinder axial direction. Is known to be. As a means for generating this tumble, for example, there is a conventional one provided with a switching valve that separates the intake passage into a top wall side passage and a bottom wall side passage by a partition wall extending in the passage axial direction and opens and closes the bottom wall side passage. . In this example, by closing the switching valve in the operation range where the intake amount is small such as the low speed rotation range,
The intake air flows unevenly toward the top wall of the intake passage and is introduced into the cylinder in the axial direction from the vicinity of the cylinder axis, and as a result, the tumble occurs.

[0003]

However, in the above conventional device, there is a problem that the shape of the intake passage is complicated by the amount of the partition wall required. Although tumble can be generated, since the partition wall and the switching valve remain in the intake passage even in the high speed operation range, the intake resistance is large and the maximum intake amount is hindered.

The applicant of the present invention has proposed an intake control device which can avoid the complicated intake passage shape and the increase in intake resistance.
A valve body having a valve portion having a notched surface corresponding to the shape of the intake passage in a cylindrical body is rotatably inserted into a valve hole formed across the intake passage. . In this intake control device, when fully closed, the valve portion reduces the area of the intake passage to allow the intake air to flow in a biased manner toward the top wall side, and a tumble can be generated by this flow deviation. on the other hand,
When the valve is fully opened, the valve portion is recessed into the bottom wall of the intake passage so that the cutout surface is continuous with the inner surface of the intake passage, so that the intake resistance does not increase.

However, when the intake control valve according to the above proposal is adopted in a multi-cylinder engine in which a plurality of cylinders are arranged in parallel, it is necessary to perform extensive machining for mounting the valve body on the cylinder head. However, since this cylinder head is large in both weight and volume, it is not easy to handle in the above-mentioned machining.

It is an object of the present invention that the shape of the intake passage is not complicated and the intake resistance at the time of full opening is not increased, and even in the case of a multi-cylinder engine, excessive machining is not required for mounting the valve body. The point is to provide an intake control device for the engine. Another object of the present invention is to provide an intake control device for an engine in which the action when the intake control valve causes the intake air to flow unevenly is not hindered by the position of the fuel injection hole from the fuel injection valve.

[0007]

The invention according to claim 1 is an intake control apparatus for an engine, wherein an intake control valve for variably controlling a passage area is provided in each intake passage connected to each of a plurality of cylinders arranged in parallel. A valve body extending in the parallel direction is mounted on the outer wall surface of the cylinder head, and an in-valve intake passage communicating with each of the intake passages is formed for each cylinder in the valve body, and a cylindrical valve body is formed in the valve body. Is inserted so as to traverse all the intake passages in the valve, and a valve portion having a notch surface having a shape corresponding to the cross-sectional shape of the intake passage in the valve is formed in each valve body for each cylinder, and With the valve body, the valve portion is fully retracted into the bottom wall of the intake passage in the valve so that the cutout surface is substantially continuous with the inner surface of the intake passage in the valve, and the intake flow is a top wall of the intake passage. Biased to the side Yo the valve unit is characterized by being rotatably supported between a fully closed position to reduce the intake passage area. The invention according to claim 2 is characterized in that a fuel supply means such as a fuel injection valve or a carburetor is further mounted on the valve body.

According to a third aspect of the present invention, the portion between the adjacent valve portions for cylinders of the valve body is formed with a small diameter, and the valve body is fixed to the cylinder head at the portion corresponding to the small diameter of the valve body. It is characterized in that mounting bolts are installed.

According to a fourth aspect of the present invention, there is provided an engine including an intake control valve for variably controlling a passage area of the intake passage, and a fuel injection valve for injecting and supplying fuel to a portion of the intake passage downstream of the intake control valve. In the intake control device, the intake control valve is provided with a valve portion formed by forming a cutout surface having a shape corresponding to the cross-sectional shape of the intake passage in a cylindrical body, and the intake control valve is parallel to the camshaft. In addition, the valve portion reduces the area of the intake passage so that the cutout surface is substantially continuous with the inner surface of the intake passage and the valve portion is fully retracted into the bottom wall and the intake flow is biased toward the top wall. A fuel injection valve is mounted on the ceiling wall of the intake passage so as to be rotatable between the fully closed position and a fuel injection hole for introducing fuel from the fuel injection valve into the intake passage. Is formed so as to open on the inner surface of the It is characterized in that is located downstream edge vicinity of the valve portion for location.

According to a fifth aspect of the present invention, in the above engine, the spark plug is arranged so as to be inclined toward the exhaust valve side with respect to the cylinder axis, and the distance from the cylinder axis to the intake cam axis in the direction perpendicular to the cam axis is from the cylinder axis to the exhaust cam. The intake camshaft is arranged so as to be shorter than the distance to the shaft in the direction perpendicular to the camshaft, and the upstream side edge portion of the fuel injection hole and the downstream side edge portion of the valve portion located at the fully closed position are provided. It is characterized in that the positions of the intake passages in the axial direction substantially coincide with each other.

[0011]

According to the engine intake control device of the present invention, in the low intake air amount operation range, the intake control valve rotates to the fully closed position side, and the intake air flows unevenly toward the top wall side and enters the cylinder. Tumble occurs in the vertical direction from around the center of the cylinder.
On the other hand, in the high intake air amount operation range, the intake control valve rotates to the fully open position, and the notch surface of the valve portion forms a substantially continuous surface with the inner surface of the intake passage, so the intake resistance does not increase.

Further, according to the present invention, the valve body and the valve unit in which the valve body is unitized are fixed to the connection mating surface formed on the wall surface of the cylinder head by bolting or the like. The machining for disposing the intake control valve on the head can be minimized, which facilitates manufacturing. Since the valve unit itself is relatively lightweight and small and can be so-called sub-assembled in another manufacturing line, manufacturing and assembling is easier than when the valve body is directly mounted on the cylinder head. Further, according to the invention of claim 2, the fuel supply means such as the fuel injection valve is attached to the valve body, so that the assemblability can be further improved.

According to a third aspect of the present invention, a portion of the valve body between adjacent cylinder valve portions is formed to have a small diameter, and the valve body is attached to a portion corresponding to the small diameter of the valve body to a cylinder head. Since the bolts are arranged, it is possible to prevent the intake control valve from increasing in size. That is, if the portion between the valve portions is also set to have the same diameter as the valve portion, the valve body becomes large in size by the boss portion of the mounting bolt.

Further, in the invention of claim 4, a fuel injection hole for introducing the fuel from the fuel injection valve mounted on the top wall of the intake passage into the intake passage is formed so as to open on the inner surface of the top wall. Since the upstream edge of the opening is located near or downstream of the downstream edge of the valve portion located at the fully closed position,
It is possible to avoid that the uneven flow action of the intake flow by the intake control valve is obstructed by the opening of the fuel injection hole. By the way, when the upstream edge of the opening is located upstream of the downstream edge of the valve portion, the flow biased toward the top wall by the valve portion is the downstream edge of the valve portion. As a result, the fuel is diffused upward at the opening of the fuel injection hole, which hinders the above-mentioned drift action.

Further, in the invention of claim 5, since the spark plug is arranged to be inclined from the cylinder axis toward the exhaust valve side and the intake cam shaft is arranged close to the cylinder axis side, near the intake passage of the cylinder head. It is possible to arrange a fuel injection valve disposed on the top wall side of the intake control valve on the downstream side. As a result, it becomes possible to position the upstream edge of the top wall opening of the fuel injection hole so as to coincide with the downstream edge of the valve section in the axial direction of the intake passage, and obstruct the intake drift action by the intake control valve. Can be avoided more reliably.

[0016]

Embodiments of the present invention will be described below with reference to the accompanying drawings. 1 to 11 are views for explaining an intake control device for a V-type engine according to an embodiment (first embodiment) of the invention of claims 1 to 5, and FIG. 1 is provided with this embodiment device. 2 and 3 are sectional front views of the apparatus of this embodiment, FIG. 4 is a bottom view, FIG. 5 is a side view of the valve unit, and FIG. 6 is VI-VI of FIG. 6 is a sectional view taken along the line, FIG. 7 is a view corresponding to FIG. 6 when fully opened, FIGS. 8 and 9 are views showing the operation of the intake control valve, and FIGS. 10 and 11 are XX of FIG.
FIG. 4 is a sectional view taken along the line XI-XI.

In the figure, 1 is a water-cooled 4-cycle V-type 8
The engine 1 is a cylinder engine, and the engine 1 has an oil pan 3 that forms a lower portion of the crank chamber connected to a lower mating surface of a skirt portion 2a that forms an upper portion of the crank chamber of the cylinder block 2.
The left and right cylinder heads 4 and 5 are connected to the mating surfaces of the left and right cylinder portions 2b and 2c forming the V bank of the cylinder block 2 by head bolts 41 arranged around the cylinder bore, and the left and right cylinders are connected. Left on the upper face of heads 4 and 5,
The structure is such that the right head covers 6 and 7 are mounted. The engine of this embodiment has the left and right cylinder portions 2b, 2
c, the left and right cylinder heads 4, 5, the left and right head covers 6, 7 and the valve operating mechanism arranged inside are symmetrical, so the following description and illustration will be made only for either left or right. There is.

Four cylinder bores (cylinders) 2d are formed in parallel in each of the cylinder portions 2b and 2c, and a piston 8 slidably inserted in each cylinder bore 2d is connected through a connecting rod 9. It is connected to the crankshaft 10.

On the cylinder block side mating surfaces 4a, 5a of the left and right cylinder heads 4, 5, there are provided four combustion recesses 11 each forming a combustion chamber. Each combustion recess 11 has a central intake valve opening 11a and left and right intake valve openings 11b and 11c and two exhaust valve openings 11d and 1d.
1e are formed, and these valve openings 11a to 11e are formed.
Is substantially located on the circumference around the cylinder axis H. Looking at the position perpendicular to the cam axis,
The right intake valve openings 11b and 11c are located closer to the cylinder axis H than the central intake valve opening 11a, that is, closer to the cylinder center side.

As shown in FIG. 4, the central intake valve opening 11a is formed to have a smaller diameter than the left and right intake valve openings 11b and 11c, so that the central intake valve opening 11a is located as close to the cylinder axis H as possible. Is located in. By moving the central intake valve opening 11a toward the cylinder axis H side, the angle θ2 of the central intake valve 14a with respect to the cylinder axis H can be approximated to the angle θ3 of the left and right intake valves 14b with respect to the cylinder axis. It is possible to suppress the flattening of the shape of the combustion chamber and improve the combustion state. By the way, if the central intake valve opening 11a has the same diameter as the left and right intake valve openings 11b and 11c, it is necessary to dispose the central intake valve opening 11a on the outside in order to avoid the interference of the respective openings, and the combustion chamber is flat. And the flammability deteriorates.

The exhaust valve openings 11d and 11e are opened and closed by an exhaust valve 12, and the exhaust valve 12 is opened and closed by an exhaust cam shaft 13. Further, the central intake valve 11a has a central intake valve 14a so that the left and right intake valve openings 11b and 11c are left,
The intake valves 14a, 14a are opened and closed by the respective intake valves 14a, 14a.
The intake cam shaft 15 opens and closes a and 14b.

Each of the exhaust valve openings 11d and 11e is led out to the outer wall of the bank of each cylinder head 4 and 5 by a bifurcated exhaust port 16, and an exhaust manifold 17 is provided in an external connection opening 16a of each exhaust port 16. Are connected.

The intake valve openings 11a to 11c are led out to the inner wall of the bank of each cylinder head 4 and 5 through an intake port (intake passage) 18. The intake port 18 includes a central passage 18a connected to the central intake valve opening 11a and left and right passages 18b connected to the left and right intake valve openings 11b and 11c.
18c and the intake valve openings 18c are joined to each other immediately upstream of the intake valve openings. The central passage 18a and the left and right passages 18b and 18c form an elliptical continuous surface in the vicinity of the external connection port 18d as shown in FIG. As shown in FIG. 11, the central passage 18a is branched so as to be offset to the cylinder block side mating surface 5a side with respect to the left and right passages 18b and 18c, and the branch is formed near the external connection port 18d. It has started.

The external connection port 1 of the intake port 18
8d is formed by cutting the inner wall of the bank of the cylinder head 5, and the intake system 19 is connected to the connection port 18d. As shown in FIG. 1, the intake system 19 fills the V bank space A formed by the left and right cylinder portions 2b and 2c, the left and right cylinder heads 4 and 5, and the left and right head covers 6 and 7. The shape is set as follows. The intake system 19 includes left and right valve units 20 and 20 connected to the external connection port 18d, and an intake manifold 21 arranged between the valve units 20 and 20 in an arch shape. The surge tank 22 is provided below the intake manifold 21.

The intake manifold 21 has a merging passage 21a connected to the valve unit 20, a long passage 25a branchingly connected to the upstream end of the merging passage 21a and opening into the surge tank 22, and a short passage. A passage 26 is provided, and a switching valve 27 having an intake passage length is arranged at a branch portion of the short passage 26.

The left and right valve units 20, 20
Is connected to each of the external connection ports 18d of the left and right cylinder heads 4 and 5 with a bolt 28 on a connection mating surface 18e formed flush with the crankshaft.
It is connected and fixed by tightening with. The valve unit 20 has a prismatic valve body 29 extending in the cam shaft direction (parallel direction of the cylinders), a valve body 23 inserted in the valve body 29 in parallel with the cam shaft and rotatably, and The fuel injection valve 24 is attached to the valve body 29.

The valve body 29 has one for each cylinder.
One in-valve intake passage 29a is formed in a horizontally long elliptical shape that is continuous with each intake passage 18 of the cylinder head 5, and the merging portion 21a of the intake manifold 21 is connected to the in-valve intake passage 29a. ing. A circular valve hole 29b common to the four cylinders is formed through the valve body 29 in the cam shaft direction.
The axis of 9a is located slightly above the inner surface of the bottom wall 29d of the intake passage 29a. The diameter of the valve hole 29 is such that the upper edge of the valve hole 29 is located slightly below the ceiling wall 29c of the intake passage 29a, and the valve portion 30 described later is housed in the bottom wall 29d of the intake passage 29a. It is set so that a semicircular groove is formed.

The valve body 23 has a structure in which a valve portion 30 is formed in a portion of the columnar member located in each of the intake passages 29a, and a portion between the valve portions 30 is a connecting portion 23a having a small diameter. The valve portion 30 is rotatably formed while being in airtight sliding contact with the inner surface of the valve hole 29b.
3a is cut to a diameter of about 1/5 of the valve portion 30. The valve body 23 is inserted into the valve hole 29b, and both ends thereof are fitted and fitted into both ends of the valve hole 29b.
It is rotatably supported by 1. In addition, the valve body 2
3 may be divided into two parts, left and right, and the two parts may be engaged with each other in a disengageable manner so that the opposing shaft part 23 ′ is supported by the bearing 31.
With this configuration, the long valve body can be smoothly and rotatably supported without causing a problem such as seizure.

A gear 3 is attached to the outward protruding end of the valve body 23.
2a is fixed, the gear 32a meshes with a gear 32b fixed to the output shaft of the servomotor 33, and the servomotor 33 is fixed to the valve body 29. The servo motor 33 controls the rotational position of the valve body 23 between a fully open position and a fully closed position by a control signal from a control unit (not shown).

The valve portion 30 has a notch surface 30 which is continuous with the inner surface of the intake passage 29a when the valve portion 30 is rotated to the fully open position.
a is formed, and an intake guide groove 30b is formed in the outer peripheral surface portion located on the back surface side of the cutout surface 30a. When this guide groove 30b is in the fully closed position and viewed in the direction perpendicular to the intake passage axis, as shown in FIG. 6, the upstream edge 30c side has a width equal to that of the intake passage 29a, and the downstream edge 30d side has the above-mentioned width. Central passage 18a and right passage 18c
It is narrowed to the side. This situation is the same when viewed in the intake passage axial direction as shown in FIG. As a result, when the valve body 23 is located at the fully closed position, the intake air is taken in by the ceiling wall
The flow will be biased toward the 9c and 18f sides and biased toward the central passage 18a and the right passage 18c. The intake guide groove 30b is, as shown by a two-dot chain line in FIG.
The left passage 18b may be formed beyond the central portion.

Here, the bolt 28 for fixing the valve body 29 to the cylinder head 5 is inserted into the small-diameter connecting portion 23a, so that the valve 28 is secured due to the securing of the arrangement position of the bolt 28. Unit 20
To avoid the increase in size.

Further, a fuel injection hole 29e is formed in the top wall portion of the valve body 29 so as to open to the inner surface of the top wall for each intake passage, and the fuel injection valve 24 is provided in each fuel injection hole 29e. Is installed. A common fuel supply rail 24a extending in the cam axis direction is attached to the upper end of each fuel injection valve 24, and the rail 24a is integrally formed with the merging portion 21a of the intake manifold 21 and is a boss portion 21b. It is fixed by bolting to.

When viewed from the side, the fuel injection hole 29e has the left and right intake valve openings 11b, 11 as shown in FIG.
It is oriented toward c. Further, when viewed from the plane, it is located on the axis of the intake passage 29a as shown in FIG.
The conical shape is expanded toward the right intake valve openings 11b and 11c. The fuel injection valve 24 is of a type having two injection ports, and each injection port has left and right intake valve openings 11
Fuel is injected toward b and 11c.

The fuel injection valve 24 may be arranged on the bottom wall side of the intake passage. In such a case,
The intake passage can be erected further toward the cylinder axis side, and the intake resistance can be reduced. Further, it is possible to connect a carburetor to the upstream end surface of the valve body 29, and in this case as well, the unit around the intake control valve can be achieved, and the assemblability can be improved.

Here, in this embodiment, the valve unit 20 is arranged closer to the intake valve openings 11a to 11c, and the following configuration is adopted in order to more reliably control the uneven flow of the intake air flow by the valve unit 20. It is adopted. The axis P of the spark plug 40 is inclined to the outside of the bank (exhaust valve side) by an angle θ1 with respect to the cylinder axis H, and accordingly the angles θ2 and θ3 of the intake valves 14a and 14b with respect to the cylinder axis H of the exhaust valve 12 are set. The angle is made smaller than the angle θ4 with respect to the cylinder axis H and the intake valves 14a and 14b are erected near the cylinder axis H. Due to the standing arrangement of the intake valves 14a and 14b, the distance from the cylinder axis H to the exhaust cam shaft 13 is L1, while the distance to the intake cam shaft 15 is small, L2. As a result, the external connection surface 1 inside the bank of the cylinder head 5
8e is formed as close to the intake valve openings 11a to 11c as possible so that the valve unit 20 and the valve body 23 are brought close to the intake valve openings 11a to 11c.

Further, due to the standing arrangement of the intake valves 14a and 14b, and further the arrangement of the intake camshaft 15 on the cylinder center side,
The fuel injection valve 24 can also be arranged so as to stand upright, and as a result, the intake passage 2 of the fuel injection hole 29e.
The upstream edge 29f of the opening to 9a can be located further downstream. In this embodiment, due to the standing arrangement of the combustion injection valve, the upstream edge 29f and the intake guide groove 3 are formed.
The position in the intake passage axial direction of the downstream edge 30d of 0b is substantially matched. This prevents the fuel injection hole 29e from opening in the intake passage, which prevents the uneven flow of the intake flow.

By the way, when a sufficient space for disposing the fuel injection valve cannot be secured on the inner wall surface of the bank of the cylinder head, the fuel injection valve has to be arranged on the inner side of the bank, that is, on the upstream side of the intake passage. In this case, even if the valve body is arranged on the downstream side, the above-mentioned upstream edge 29f is formed.
Moves to the upstream side of the downstream edge 30d of the valve portion 30, and there is no wall surface facing the downstream edge 30d.
The uneven flow action of the intake air flow by the valve portion 30 is hindered.

Next, the function and effect of the apparatus of this embodiment will be described. In an operating range in which the engine speed is 2600 rpm or less and the throttle opening is about 20% or less and the intake air amount is relatively small at a low load (low intake air amount operating range), the valve body 23 is shown in FIGS. The intake passage length switching valve 27 (see FIG. 1) closes the short passage 26 while rotating to the fully closed position. Then, the intake air flows from the surge tank 22 to the long passage 2
5 is introduced into the cylinder bore 2d via the intake passages 29a and 18. In this case, the intake air is biased toward the ceiling walls 29c and 18f of the intake passage by the valve portion 30 and is connected to the right intake valve opening 11c by the intake guide groove 30b, and the central passage 18a is connected to the central intake valve opening 11a. And is mainly introduced into the cylinder bore 2d through the right and center intake valve openings 11c and 11a.

The above-mentioned deviation of intake air flow will be described conceptually. As for the deviation of the intake passage in the vertical direction, as shown by the six arrows in FIG.
Flows toward the side. On the other hand, regarding the deviation of the intake passage in the width direction, as shown by the six arrows in FIG. 6, most of the intake air is diverted toward the central passage 18a and the right passage 18c by the intake guide groove 30b, and a part of Flows to the left passage 18b side between the outer peripheral surface of the portion 30 and the top wall 29c of the intake passage 29a, resulting in right, center, left intake valve openings 11c, 11a,
The amount of intake air into 11b is large, medium, and small, respectively.

As described above, in this embodiment, the intake air flow is biased toward the top wall of the intake passage and is biased to the right intake valve opening 11c and the central intake valve opening 11a. The intake air flow from the
(See the arrow a in FIG. 2).
(See FIG. 6), there is a tendency of so-called tumble flow, and when viewed in the cylinder axial direction, as shown by an arrow a in FIG.
It flows along the inner peripheral surface of d and exhibits a so-called swirl flow tendency. As a result, although not shown, when viewed in the direction perpendicular to the cam axis (direction of arrow b in FIG. 2), the right intake valve opening 11c is opened.
The intake air flow from the air flows obliquely so as to become lower toward the left intake valve opening 11b side. Therefore, in this embodiment, a so-called oblique swirl flow such as a combination of the tumble flow and the swirl flow is generated in the cylinder bore 2d. .

The fuel from the fuel injection valve 24 is supplied to the left and right intake valve openings 11b and 11 as shown by the broken line in FIG.
It is injected toward c. Therefore, regarding the concentration of the air-fuel mixture introduced into the cylinder bore 2d, the concentrations of the air-fuel mixture from the left, right, and center intake valve openings 11b, 11c, and 11a are large, medium, and small, respectively.

As described above, in this embodiment, the so-called oblique swirl can be generated in the intake air flow introduced into the cylinder bore 2d in the operating range where the intake air amount is relatively small, and as a result, the combustion state can be improved. .

For example, in an engine having the same structure as this embodiment and having no intake control valve, the throttle opening 20
%, To obtain a stable engine operating condition at an engine speed of 1500 rpm, set the ignition timing to 35 ° before top dead center.
Had to be set to. On the other hand, in the case of the engine of this embodiment, the ignition timing is set to 15 ° before top dead center under the same conditions as above.
A stable driving condition was obtained even when the vehicle was retarded to.
From the fact that a stable operating state was obtained while retarding the ignition timing in this way, it is understood that the engine of the present embodiment has a better combustion state.

Here, when the valve body 23 is rotated to the fully closed position, the valve body 23 becomes an intake resistance, and there is a concern that the intake amount may be insufficient. On the other hand, in this embodiment,
In the low load operation range, the intake passage length switching valve 27
In this operating range, switching is made to the long passage 25 side having a length such that the inertia supercharging effect is obtained. Therefore, due to the effect of inertial supercharging by the intake passage length, the shortage of the intake air amount due to the intake resistance by the valve body 23 can be compensated, and the required intake air amount can be secured.

The engine speed is, for example, 2600-
At 4600 rpm, in the medium speed rotation / medium load region where the throttle opening is, for example, about 40%, the valve body 23 rotates to the fully open position, and the valve portion 30 is retracted into the valve hole 29b as shown in FIG. The cutout surface 30a forms a continuous surface with the inner surface of the intake passage 29a. As a result, there is no resistance that remains in the intake passage, the intake resistance can be eliminated, and the required amount of intake air can be secured.

The engine speed is, for example, 4600r.
In the high-speed high-load operation region where the throttle opening is substantially fully opened at pm or more, the passage length switching valve 27 further opens the short passage 26. As a result, most of the intake air is introduced into the cylinder through the short passage 26 of a length that provides the effect of inertia supercharging in the high speed rotation range, and the rest is introduced into the cylinder through the long passage, and a large amount of intake air is generated in the high speed rotation range. Secured.

Further, in this embodiment, the valve unit 20 is provided upstream of the branch start portion of the central passage 18a, which constitutes the intake passage 18, and the left and right passages 18b and 18c in the cylinder axial direction.
Since the above is provided, the structure of the valve body 23 can be particularly simplified, and the diameter of the valve body 23 can be minimized. By the way, when it is arranged on the downstream side from the branch start portion, it is necessary to make the outer shape and the notch surface shape of the valve body correspond to the passage cross-sectional shape shown in FIG. 11, for example, and the shape becomes extremely complicated. Its diameter increases. On the other hand, the valve body of the present embodiment has a simple cylindrical shape and a simple elliptical cutout surface 30b, which is simple in shape and has a small diameter.

Further, in this embodiment, since the ignition plug 40 is inclined toward the exhaust side and the intake valves 14a and 14b are raised, the intake camshaft 15 is arranged closer to the center side of the cylinder. A space is obtained on the intake side, and the valve unit 20 can be arranged on the upstream side of the above-mentioned branch start portion and closer to the intake valve openings 11a to 11c. As a result, while simplifying the above-mentioned valve structure,
The controllability of the intake flow can be improved. That is, when the intake control valve of the structure of this embodiment is provided, the above-mentioned drift toward the top wall side spreads as the valve body 23 moves away from the intake valve opening. By adopting such an arrangement structure, the valve element 23 can be brought close to the intake valve opening.

Further, in this embodiment, the lube body 29, the valve body 23, the fuel injection valve 24, and the driving servomotor 33 are used.
Since the valve unit 20 formed by unitizing the above is detachably mounted on the external connection surface 18e of the cylinder head with the mounting bolts 28, processing and assembly around the cylinder head in the case of an engine having many cylinders is easy. is there. For example, when the structure in which the valve body is directly inserted into the cylinder head is adopted, the number of man-hours for handling the cylinder heads 4 and 5 having large weight and volume is increased, so that the work load is increased. On the other hand, in the case of the present embodiment, a sub-assembly for processing and assembling the valve unit 20 in another manufacturing line is possible, and since this valve unit 20 is lightweight and compact, it is easy to handle, and it is viewed as a whole. In this case, the number of manufacturing steps can be reduced.

In the above embodiment, the fuel injection valve 24 is arranged on the axis of the intake passage, and the fuel is injected into the left and right intake valve openings 1
Although the fuel is injected toward 1b and 11c, various modified examples can be adopted for the arrangement position of the fuel injection valve and the fuel injection direction. For example, as shown in the second embodiment in FIGS. 12 and 13, the fuel injection valve 24 is arranged between the right passage 18c and the central passage 18a, and the fuel from the two injection ports is inserted into the right intake valve opening 11c and the center. Injection is supplied toward the intake valve opening 11a.

In the case of the second embodiment, the deviation of the intake flow and the ratio of the intake air amount from each intake valve opening are the same as those of the first embodiment. On the other hand, regarding the concentration of the air-fuel mixture,
The air-fuel mixture concentrations from the left intake valve openings 11a, 11c and 11b are high, medium and low, respectively. As a result, the air-fuel mixture with the highest concentration from the central intake valve opening 11a is the spark plug 40.
Since it will be introduced in the vicinity, the combustion state can be stabilized. In particular, even when the fuel concentration of the entire air-fuel mixture is made low, ignition is assured, so lean combustion can be stabilized, which is advantageous in purification of exhaust gas.

Here, when the arrangement position of the fuel injection valve and the fuel injection direction as shown in the second embodiment are adopted, as shown in the third embodiment in FIGS. 14 and 15, the left passage 18b is formed.
It is also possible to provide a partition wall for separating the central passage and the right passages 18a and 18c. The partition wall is composed of a head-side partition wall 18h provided in the intake passage 18 and a valve body-side partition wall 29g provided in the intake passage 29a.

In the case of the third embodiment, the fuel can be more reliably supplied to the side where the intake air amount is large, so that the stabilization of the combustion state in the second embodiment can be further improved.

In the case of the third embodiment, the partition wall 18h in the intake passage 18 may be formed with a communication hole 18g that obliquely penetrates from the central and right passages 18a and 18c side to the left passage 18b side. . By doing so, a part of the fuel is also supplied to the left intake valve opening 11b side through the communication hole 18g. As a result, this fuel causes left intake valve opening 1
The back surface of the left intake valve 14b that opens and closes 1b can be cooled, and overheating of the intake valve 14b can be avoided.

In the first to third embodiments, the valve body 23
The case where the intake guide groove 30b formed in the valve portion 30 of the above is formed so as to bias intake air to the right intake valve opening 11c and the central intake valve opening 11a has been described. Various modifications can be adopted for the direction.

For example, as shown by the chain double-dashed line in FIG.
By setting the downstream edge 30d of the intake guide groove 30b to be narrower to the width facing only the right passage 18c, the intake air may flow mainly in the right intake valve opening 11c only in a biased manner. It is the invention of claim 5. When the intake guide groove 30b is formed in such a shape, the intake amount introduced from the central intake valve opening 11a decreases and the intake amount introduced from the right intake valve opening 11c increases. As a result, the concentration of the air-fuel mixture introduced near the spark plug is further increased, and the ignitability is further improved.

Regarding the shape of the intake guide groove,
As shown in FIGS. 16 to 19 in which the fourth embodiment according to the invention of claim 3 is shown, intake air can be formed so as to be able to flow in the left and right intake valve openings 11b and 11c. Here, the term “biased flow” in the present embodiment means that the left and right flow rates are larger than those of the above-described case without the guide groove, which means that a large amount of intake air always flows from the central portion. Not a thing. That is, in the case where the engine of this embodiment has three intake valve openings, a large amount of intake air tends to flow to the central intake valve opening, and the guide groove corrects this tendency. Therefore, as a result, there may be cases where the left, the right, and the center have the same intake air amount.

In the fourth embodiment, the left and right guide grooves 30e and 30f are formed on the outer peripheral side of the valve portion 30 in a bifurcated shape so as to flow toward the left and right intake valve openings 11b and 11c, respectively. Further, the two injection ports of the fuel injection valve 24 are adapted to inject and supply fuel toward the left and right intake valve openings 11b and 11c.

In the fourth embodiment, when the valve body 23 is rotated to the fully closed position, a large amount of intake air is absorbed from the left and right intake valves 11b and 11c as compared with the valve body having no guide groove.
It is introduced into the inside, and the rest is introduced from the central intake valve opening 11a. In this case, the left and right intake valve openings 11b, 11
The intake flow from c cancels each other with respect to the tendency of the swirl flow, so that the tumble flow can be generated more reliably. In addition, since the intake air is diverted to the left and right opening sides by the guide groove,
There may be cases where the left and right intake volumes and the central intake volume are equal.

On the other hand, most of the fuel is injected and supplied toward the left and right intake valve openings 11b and 11c, and a very small amount of fuel diffused around is supplied to the central intake valve opening 11a. Therefore, the fuel concentration in the air-fuel mixture becomes relatively high and the same in the left and right intake valve openings 11b and 11c.

As described above, in this embodiment, the intake air is guided by the left and right guide grooves 30e and 30f.
Since the flow is biased to b and 11c, the tumble can be generated more reliably in the intake air flow introduced into the cylinder bore, and as a result, the combustion state can be improved.

In each of the above embodiments, the case where the valve body is provided separately from the cylinder head has been described, but in the inventions of claims 4 and 5, the valve body may be integrated with the cylinder head.

[0063]

As described above, according to the intake control system for an engine of the present invention, since the intake control valve that causes the intake to flow toward the top wall side is provided in the low intake air amount operation range, the intake is controlled by the cylinder axis. There is an effect that tumble can be generated by vertically flowing into the cylinder from the vicinity of the center, and the combustion state of the engine can be improved. On the other hand, in the high intake air amount operation range, the valve portion is recessed in the bottom wall of the intake passage and the notch surface is substantially continuous with the inner surface of the intake passage, so that the intake resistance does not increase.

Further, according to the present invention, a valve body and a valve body unit are formed, and in the invention of claim 2, a valve unit in which the fuel injection valve is also formed as a unit is bolted to a connection mating surface formed on the wall surface of the cylinder head. Since it is fixed by means such as, the machining for disposing the intake control valve for a large-weight and large-capacity cylinder head can be minimized, and the valve unit can be sub-assembled. This has the effect of facilitating the manufacturing and assembly of the control device.

According to the third aspect of the present invention, the portion of the valve body between the adjacent cylinder valve portions is formed to have a small diameter, and the valve body is fixed to the cylinder head at the portion corresponding to the small diameter of the valve body. Since the mounting bolts are installed, there is an effect that the enlargement of the valve body can be avoided.

Further, in the invention of claim 4, when the fuel injection hole is opened to the inner surface of the ceiling wall, the upstream side edge portion of the opening is in the vicinity of the downstream side edge portion of the valve portion located at the fully closed position or Since it is located on the downstream side, there is an effect that it is possible to prevent the unbalanced action of the intake flow by the intake control valve from being obstructed by the opening of the fuel injection hole.

Further, in the invention of claim 5, since the spark plug is arranged to be inclined to the exhaust valve side with respect to the cylinder axis and the intake cam shaft is arranged to be shifted to the cylinder axis side, the vicinity of the intake passage of the cylinder head is provided. The fuel injection valve disposed on the top wall side of the intake control valve can be disposed further downstream, and as a result, the upstream edge of the top wall opening of the fuel injection hole can be located downstream of the valve portion. It is possible to position the side edge portion so as to coincide with the axial direction of the intake passage, and it is possible to more reliably avoid the obstruction of the intake bias flow action by the intake control valve.

[Brief description of drawings]

FIG. 1 is a schematic front view of an engine including an intake control device according to an embodiment (first embodiment) of the present invention.

FIG. 2 is a sectional front view of the device of the first embodiment in a fully closed state.

FIG. 3 is a sectional front view of the apparatus of the first embodiment in a fully opened state.

FIG. 4 is a bottom view of the device of the first embodiment.

FIG. 5 is a side view of the valve unit of the first embodiment device.

FIG. 6 is a cross-sectional plan view (cross-sectional view taken along line VI-VI in FIG. 2) showing a fully closed state of the first embodiment device.

FIG. 7 is a cross-sectional plan view showing a fully opened state of the device of the first embodiment.

FIG. 8 is a sectional side view showing a fully closed state of the valve portion of the first embodiment device.

FIG. 9 is a sectional side view showing a fully opened state of the valve portion of the first embodiment device.

FIG. 10 is a cross-sectional side view (cross-sectional view taken along line XX in FIG. 6) of the intake passage portion of the first embodiment device.

FIG. 11 is a sectional side view (sectional view taken along line XI-XI of FIG. 6) of the intake passage portion of the first embodiment device.

FIG. 12 is a cross-sectional plan view showing a fully closed state of a second embodiment device corresponding to a modification of the first embodiment.

FIG. 13 is a cross-sectional plan view showing the fully open state of the second embodiment device.

FIG. 14 is a third embodiment corresponding to another modification of the first embodiment.
It is a cross-sectional top view which shows the fully closed state of an Example apparatus.

FIG. 15 is a cross-sectional plan view showing the fully open state of the device of the third embodiment.

FIG. 16 is a cross-sectional plan view showing a fully closed state of the intake control device of an embodiment (fourth embodiment) of the invention of claim 3;

FIG. 17 is a sectional plan view showing the fully-opened state of the device of the fourth embodiment.

FIG. 18 is a sectional side view showing a fully closed state of a valve portion of the fourth embodiment device.

FIG. 19 is a sectional side view showing a fully opened state of the valve portion of the apparatus of the fourth embodiment.

[Explanation of symbols]

 1 engine 2d cylinder bore (cylinder) 4,5 cylinder head 12 exhaust valve 13,15 exhaust, intake camshaft 18 intake passage 18e connection surface (outer wall surface) 20 valve unit 23 valve body 23a connection part (portion between valve parts) ) 24 combustion injection valve 28 mounting bolt 29 valve body 29a in-valve intake passage 29c top wall 29d bottom wall 29e fuel injection hole 29f opening upstream side edge 30 valve portion 30a cutout surface 30d downstream side edge portion 40 spark plug H cylinder axis L1 cylinder axis to exhaust cam axis distance L2 cylinder axis to intake cam axis distance

Claims (5)

[Claims] 1. An intake control device for an engine, wherein an intake control valve for variably controlling a passage area is provided in each intake passage connected to each of a plurality of cylinders arranged in parallel. The intake control device extends to the outer wall surface of a cylinder head in the parallel direction. A valve body is mounted, an in-valve intake passage communicating with each of the intake passages is formed for each cylinder in the valve body, and a cylindrical valve body is formed in the valve body so as to traverse all of the in-valve intake passages. The valve body is inserted into the valve body, and a valve portion having a cutout surface having a shape corresponding to the cross-sectional shape of the intake passage in the valve is formed for each cylinder, and the valve body is formed by the valve body. The fully open position where the valve portion is recessed into the bottom wall of the intake passage in the valve so as to form a substantially continuous surface with the inner surface of the intake passage, and the valve portion has an intake passage area so that the intake flow is biased toward the top wall side of the intake passage. Shrink An intake control device for an engine, wherein the intake control device is rotatably supported between a fully closed position. 2. The intake control device for an engine according to claim 1, wherein a fuel supply unit is attached to the valve body. 3. The cylinder head according to claim 1 or 2, wherein a portion of the valve body between adjacent cylinder valve portions is formed to have a small diameter, and the valve body is attached to a portion corresponding to the small diameter of the valve body. An intake control device for an engine, characterized in that a mounting bolt for fixing to the engine is arranged. 4. An intake control device for an engine, comprising: an intake control valve for variably controlling a passage area of an intake passage; and a fuel injection valve for injecting fuel into a portion of the intake passage downstream of the intake control valve. The intake control valve is provided with a valve portion formed by forming a notch surface having a shape corresponding to the cross-sectional shape of the intake passage in a cylindrical body, and the intake control valve is provided in parallel with the cam shaft and with the notch. Between a fully open position where the valve portion is recessed into the bottom wall so that the surface is substantially continuous with the inner surface of the intake passage, and a fully closed position where the valve portion reduces the intake passage area so that the intake flow is biased toward the ceiling wall. Mounted on the top wall of the intake passage, and a fuel injection hole for introducing fuel from the fuel injection valve into the intake passage is opened on the inner surface of the top wall. And the upstream side edge portion of the opening is located at the fully closed position. An intake control device for an engine, wherein the intake control device is located near a downstream edge. 5. The engine according to claim 4, wherein the engine is arranged such that the spark plug is tilted toward the exhaust valve side from the cylinder shaft, and the distance from the cylinder shaft to the intake cam shaft in the direction perpendicular to the cam axis is from the cylinder shaft to the exhaust cam. The intake camshaft is arranged so as to be shorter than the distance to the shaft in the direction orthogonal to the camshaft, and the upstream side edge portion of the fuel injection hole and the downstream side edge portion of the valve portion located at the fully closed position. An intake control device for an engine, wherein the positions of the intake passages in the intake passage are substantially the same.