JP3334064B2 - Engine intake control device - Google Patents

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 having 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 the combustion state of an engine, especially in a low-speed rotation region, it is effective to generate a vertical vortex having a direction in the cylinder axis direction, that is, a so-called tumble, in an intake air introduced into the cylinder. It is known that

As means for generating the tumble, conventionally, for example, a butterfly type switching valve for separating an intake passage into a top wall side passage and a bottom wall side passage by a partition extending in the passage axial direction and opening and closing the bottom wall side passage. Some have. In this example, in an operation range where the amount of intake air is small, such as a low-speed rotation range, by closing the switching valve, the intake air flows toward the top wall side of the intake passage, and flows into the cylinder in the axial direction from near the cylinder axis. Introduced in a directed manner, resulting in the tumble.

[0004]

However, in the case of the above-mentioned conventional apparatus, there is a problem that the shape of the intake passage is complicated by the necessity of the partition. In addition, although a tumble can be generated, there is a problem that the partition wall and the switching valve have a large intake resistance and the intake noise increases.

The applicant of the present application has disclosed an intake control device which can avoid the complicated intake passage shape and an increase in intake resistance.
It has been proposed that a valve body having a valve portion having a cutout surface having a shape corresponding to the shape of the intake passage in a cylindrical body is rotatably inserted and disposed in a valve hole formed so as to cross the intake passage. .

In this intake control device, when the valve is fully closed, the valve section reduces the intake passage area and allows the intake air to flow toward the top wall side, and a tumble can be generated by the uneven flow.
On the other hand, when the valve is fully opened, the valve section is immersed in the bottom wall of the intake passage, and the cutout surface forms a continuous surface with the inner surface of the intake passage, so that the intake resistance does not increase.

However, the intake control valve according to the above proposal is
When employed 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, but since this cylinder head is large in both weight and volume, It is not easy to handle in machining.

An object of the present invention is not to complicate the intake passage shape or increase the intake resistance at the time of full opening, and to avoid excessive machining for mounting a valve body even in a multi-cylinder engine. It is to provide an intake control device for an engine. Another object of the present invention is to provide a swirl swirling flow around a cylinder axis in a cylinder while adopting a configuration in which intake air is deflected toward the top wall of an intake passage by an intake control valve to generate a tumble in the cylinder. Is also to be generated. Furthermore, it is another object of the present invention to control the tumble and swirl with a simple configuration.

[0009]

According to a first aspect of the present invention, there is provided an intake control device for an engine, wherein a valve body for an intake control valve is provided in a cylinder head, the valve body having an intake passage in a valve communicating with an intake passage of a cylinder head. The intake passage in the valve is formed in a shape corresponding to the cross-sectional shape of the intake passage of the cylinder head, and the bottom wall of the intake passage in the valve is moved toward the top wall in the closed state to close the intake flow. Is provided to the top wall side, and a closed state intake guide groove for directing the intake air flow to at least one of the axial directions of the intake camshaft is provided in the valve element.

An engine intake control device according to a second aspect of the present invention is the engine intake control device according to the first aspect, wherein the valve body is formed separately from the cylinder head. An intake control device for an engine according to a third invention is the intake control device for an engine according to the first or second invention, wherein three intake valves are provided, and an intake passage of a cylinder head is provided near each intake valve for each intake valve. The side intake passage located at the shaft end of the intake camshaft among the three intake passages as viewed from the upstream side of the intake air flow, and the central intake It is positioned on the side of the side intake passage with respect to the partition wall between the passage and the passage.

According to a fourth aspect of the present invention, there is provided an intake control system for an engine according to any one of the first to third aspects, wherein the valve in the intake passage in the valve and the intake passage of the cylinder head is provided. The side wall on the intake guide groove side of the body is expanded laterally from the intake passage when the valve body is in a fully opened state.

According to a fifth aspect of the present invention, there is provided an intake control device for an engine according to any one of the first to fourth aspects, wherein the intake guide groove of the valve body is arranged to be downstream from the upstream end. It is formed so that it becomes gradually narrower toward the end.

According to a sixth aspect of the present invention, there is provided an intake control system for an engine according to any one of the first to fifth aspects, wherein a valve element is partially provided in the intake passage in the valve. The valve body is formed in a substantially cylindrical shape that is immersed in the bottom wall, and is supported by the valve body so as to be rotatable around the cam axis direction. The valve body has a cutout surface having a shape corresponding to the cross sectional shape of the intake passage in the valve. A fully-open intake guide groove and a closed-state intake guide groove for biasing the intake air flow toward the top wall of the in-valve intake passage are formed.

[0014]

[0015]

According to the first aspect of the present invention, when the bottom wall of the intake passage in the valve is moved toward the top wall, the intake air flow is biased toward the top wall of the intake passage in the valve, and the center of the cylinder is located in the cylinder. It flows in the vertical direction from the vicinity, and tumble occurs. The valve body moves the bottom wall of the in-valve intake passage toward the top wall and enters the closed state, so that the intake resistance is small even in the closed state. Further, when the bottom wall of the in-valve intake passage is moved toward the top wall, the intake air flow is deviated to one of the top wall side and the cam shaft direction of the in-valve intake passage. Therefore, a tumble is generated in the cylinder and a swirl composed of a swirling flow around the cylinder axis is also generated.

According to the second aspect of the present invention, the valve unit, which is a unit of the valve body and the valve body, is mounted on the cylinder head, so that the intake control valve is provided for the heavy and large volume cylinder head. Machining can be minimized. The valve unit itself is relatively lightweight and small, and can be so-called sub-assembly in another production line. Therefore, the production and assembly is easier than in the case where the valve body is directly mounted on the cylinder head.

[0017]

According to the third aspect of the present invention, the intake air that has passed through the intake guide groove for the closed state flows mainly to the side intake passage, so that the tendency of swirl to occur in the cylinder increases. According to the fourth aspect, the intake air that has passed through the intake guide groove for the closed state passes through the expanded portion of the intake passage side wall, and the side intake passage from the side with respect to the inflow path when the valve body is fully opened. Therefore, swirl is easily generated in the cylinder.

According to the fifth aspect, the resistance when the intake air passes through the closed-state intake guide groove is reduced, so that the intake resistance is further reduced. In addition, since turbulence is unlikely to occur downstream of the closed-state intake guide groove and the intake air flows smoothly, the flow rate of the intake air can be ensured. According to the sixth aspect, the intake control device is assembled by forming a circular valve hole in the valve body and fitting the valve body into the valve hole.

[0020]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIGS. 1 to 11 are views for explaining an intake control device for a V-type engine according to one embodiment of the first to sixth inventions. FIG. 1 is a schematic front view showing the overall configuration of an engine equipped with the present embodiment, FIGS. 2 and 3 are cross-sectional front views of the present embodiment, and FIG. 4 is a bottom view.

FIG. 5 is a side view of the valve unit, FIG. 6 is a sectional view taken along line VI-VI in FIG. 2, and FIG.
FIG. 8 is a view showing a state in which the valve body is turned to the fully closed position, and FIG. 8 is a sectional view taken along line VIII-VIII in FIG.
FIG. 9 is a view showing a state where the valve body is rotated to the fully open position, and FIG. 9 is a cross-sectional view taken along line IX-IX in FIG. FIG. 10 shows FIG.
FIG. 11 is a sectional view taken along line XX in FIG. 6, and FIG. 11 is a sectional view taken along line XI-XI in FIG.

In these figures, reference numeral 1 denotes a water-cooled 4-cycle V-type 8-cylinder engine. This engine 1 has a skirt portion 2 forming an upper part of a crank chamber of a cylinder block 2.
an oil pan 3 that forms a lower portion of the crankcase on the lower mating surface of the oil pan 3
And the left and right cylinder heads 4 and 5 are joined to the mating surface of the left and right cylinder portions 2b and 2c forming the V bank of the cylinder block 2 with head bolts 1a arranged around the cylinder bores. , Right cylinder heads 4, 5 are attached with left and right head covers 6, 7 on the upper mating surfaces. In the engine of the present embodiment, the left and right cylinder portions 2b and 2c, the left and right cylinder heads 4 and 5, the left and right head covers 6, 7 and the valve operating mechanisms disposed therein are symmetrical. The following description and illustration may be made only for either the left or right.

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

Each of the left and right cylinder heads 4, 5 is provided with four combustion recesses 11 which form combustion chambers on the cylinder block side mating surfaces 4a, 5a. Each combustion recess 11 has a central intake valve opening 11a, left and right intake valve openings 11b, 11c, and two exhaust valve openings 11d, 1d.
1e are formed, and these valve openings 11a to 11e
Is located substantially on the circumference around the cylinder axis H. Looking at the position in the direction perpendicular to the cam shaft,
The left and right intake valve openings 11b and 11c correspond to the central intake valve opening 11
It is located closer to the cylinder axis H than a, that is, closer to the cylinder center. The central intake valve opening 11a is provided with a central intake valve 12a.
The left and right intake valve openings 11b and 11c are opened and closed by left and right intake valves 12b and 12b. The intake valves 12 a and 12 b are configured to be opened and closed by an intake camshaft 13. The exhaust valve openings 11d and 11e are opened and closed by an exhaust valve 14. The exhaust valve 14 is configured to be opened and closed by an exhaust cam shaft 15.

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 as close to the cylinder axis H as possible. Is located. By moving the central intake valve opening 11a toward the cylinder axis H, the angle θ2 of the central intake valve 12a with respect to the cylinder axis H can be approximated to the angle θ3 of the left and right intake valves 12b with respect to the cylinder axis H. The flattening of the shape of the combustion chamber can be suppressed by that much, and the combustion state can be improved. By the way, central intake valve opening 1
If 1a is made the same diameter as the left and right intake valve openings 11b and 11c, the central intake valve opening 11 is used to avoid interference between the openings.
It becomes necessary to arrange a outside, and the combustion chamber is flattened accordingly, and the flammability deteriorates. Further, the squish area can be secured by moving the central intake valve opening 11a toward the cylinder axis H.

Each of the exhaust valve openings 11d and 11e is a bifurcated exhaust port 16 extending to the outer wall of the bank of each of the cylinder cylinder heads 4 and 5.
The exhaust manifold 17 is connected to the external connection opening 16a.

The intake valve openings 11a to 11c are led out to the inside walls of the banks of the cylinder heads 4 and 5 through intake ports 18 as intake passages in the cylinder head. In the intake port 18, the central passage 18a connected to the central intake valve opening 11a and the left and right passages 18b, 18c connected to the left and right intake valve openings 11b, 11c are merged on the immediately upstream side of each intake valve opening. Of shape. The central passage 18a and the left and right passages 18b and 18c form an elliptical continuous surface near the external connection port 18d as shown in FIG.
As shown in the figure, the central passage 18a has left and right passages 18b, 18
It is branched so as to be deviated to the cylinder block side mating surface 5a side with respect to c, and the branch starts near the external connection port 18d.

The external connection port 18d of the intake port 18 is formed by cutting the inner wall of the bank of the cylinder head 5, and an air intake device 19 is connected to the connection port 18d. Also, this intake port 18
10 and 11 on the side of the left passage 18b in FIG.
As shown in FIG. 5, an intake air inlet groove 18e is formed by bulging a part of the side wall to the side. This intake introduction groove 18e
Are three passages 1 in plan view shown in FIGS. 6 and 7.
Like 8a to 18c, it is opened on the inner wall of the bank of the cylinder head 5, and extends to the vicinity of the left intake valve opening 11b.

As shown in FIG. 1, the intake device 19
V formed by left and right cylinder portions 2b and 2c, left and right cylinder heads 4 and 5, and left and right head covers 6 and 7.
It is configured to fill the bank space A.

The intake device 19 is connected to the external connection port 18.
d, left and right valve units 20,
An intake manifold 21 is arranged between the valve units 20 and 20 in an arched manner, and a surge tank 22 suspended below the intake manifold 21. The intake manifold 21 includes:
A merging passage 23 (FIGS. 2 and 3) connected to the valve unit 20 and a long passage 24 branched and connected to an upstream end of the merging passage 23 and opening into the surge tank 22.
And a short passage 25. In addition, short passage 25
A switching valve 26 having an intake passage length is disposed in the branch portion of the air conditioner.

The left and right valve units 20, 20
As shown in FIGS. 2 and 3, the bolt 27 is used to connect the intake port 18d of each of the left and right cylinder heads 4 and 5 to a connection mating face 18f formed flush with and parallel to the crankshaft 10. It is connected and fixed to the manifold 21 by co-fastening. The valve unit 20 has a prismatic valve body 2 extending in a camshaft direction (a direction in which the cylinders are arranged in parallel).
8, a valve body 29 rotatably inserted in the valve body 28 in parallel with the camshaft, and a fuel injection valve 30 attached to the valve body 28.

The valve body 28 has one cylinder for each cylinder.
Two in-valve intake passages 31 are formed in a horizontally long elliptical shape which forms a continuous surface with each intake port 18 of the cylinder head 5. As shown in FIGS. 21 are connected to each other.

Further, a circular valve hole 32 common to the four cylinders is formed in the valve body 28 so as to extend therethrough in the cam axis direction. The axis of the valve hole 32 corresponds to the intake passage 31 in the valve.
Is located slightly above the inner surface of the bottom wall 31a. The diameter of the valve hole 32 is set so that the upper edge thereof is located slightly below the top wall 31b of the in-valve intake passage 31.
In the bottom wall 31a, a valve portion 29a of a valve body 29 described later is provided.
Is formed so that a semicircular groove for accommodating therein is formed.

The valve element 29 has a valve section 29a that crosses the in-valve intake passage 31 and is formed in a substantially columnar shape provided for each intake passage, and a small-diameter connecting section 29b is provided between the valve sections 29a.
Are formed. The valve portion 29a is formed to be rotatable while substantially slidingly contacting the inner surface of the valve hole 32 in an airtight manner. The valve element 29 is inserted into the valve hole 32, and both ends are rotatably supported by bearings 33 fitted and mounted in both ends of the valve hole 32. In addition, as shown in FIG. 5B, the valve body 29 may be divided into two parts, left and right, and both may be detachably fitted to each other, and the opposing shaft portion 34 is supported by the bearing 33. Good. With this configuration, the long valve body can be smoothly and rotatably supported without causing a problem such as seizure.

Here, a bolt 27 for fixing the valve body 28 to the cylinder head 5 is inserted through the small-diameter connecting portion 29b.
This prevents the valve unit 20 from becoming large due to securing the arrangement position of the valve unit 7.

A gear shaft 29c is formed at the outer discharge end of the valve body 29 located on the right side in FIG. A gear 35 is fixed to the gear shaft 29c, and is connected to a servomotor 37 via a gear 36 meshing with the gear 35. The servomotor 37 is supported and fixed to the valve body 28, and is configured to control the rotational position of the valve body 29 between a fully closed position and a fully open position described later by a control signal from a control unit (not shown). .

In the apparatus of this embodiment, the valve body 29 is rotated to the fully open position when the engine is operated at a higher speed / higher load range than at a medium speed / medium load range. It is assumed that the engine is turned to the position when the engine is operated in a low-speed rotation / low-load range. In addition to the configuration in which the two opening positions of the fully open position and the fully closed position are switched as described above, the configuration in which the opening is gradually changed between the fully open position and the fully closed position according to the engine operating state. Can also be taken.

The valve portion 29a is formed with a cutout surface 29d which forms a continuous surface with the inner surface of the in-valve intake passage 31 when the valve body 29 is rotated to the fully open position. An intake guide groove 38 is formed in an outer peripheral surface portion located on the back surface side of the air conditioner. The fully open position of the valve body 29 is defined by the notch surface 29 as shown in FIGS.
The opening position is such that d is continuous with the inner surface of the in-valve intake passage 31. Further, the fully closed position of the valve body 29 is defined as the intake guide groove 3 as shown in FIGS.
8 is an opening position at which the intake passage 31 faces the inside of the valve intake passage 31 and the downstream edge 38a of the intake guide groove 38 approaches the top wall 31b to reduce the intake passage area. When the valve body 29 is turned to the fully closed position, the valve portion 2
A small gap G is formed between the outer peripheral surface 9a and the top wall 31b as shown in FIG. Also,
When the valve body 29 is rotated from the fully open position to the fully closed position, the valve body 29 is rotated clockwise in FIGS. 2 and 3, and when the valve body 29 is rotated from the fully closed position to the fully open position, the reverse of the above is performed. Turn counterclockwise.

When the valve body 29 is rotated to the fully closed position in this manner, the intake passage 31 in the valve is formed by the space formed by the gap G, the intake guide groove 38 and the top wall 31b as shown in FIG. Is substantially closed so that the intake air flows only in the space between the two. The space through which the intake air flows at this time is hereinafter referred to as a fully closed ventilation space S. When the gap G is formed, 3
Since the amount of intake air over the three passages can be controlled, the tumble and swirl can be controlled by the intake air flowing into the cylinder from the three passages. Note that, in the present embodiment, an example is shown in which the intake air also flows into the space formed by the gap G, but the gap G is narrowed so that only the space between the intake guide groove 38 and the top wall 31b is mainly provided. A configuration in which intake air flows can also be used. It is desirable that the gap G has a certain size in consideration of productivity. This is because when the gap G is reduced, the notch 29
This is because the corners serving as the upstream edge and the downstream edge of d become sharp, and the corners may be damaged if they hit the valve body 28 during assembly.

When the intake guide groove 38 is in the fully closed position and viewed in a direction perpendicular to the intake passage axis, as shown in FIG. 6, the upstream edge 38b has a valve width approximately half that of the intake passage 31 in the valve. One side in the axial direction of the body 29 (the left passage 18b
), And is narrower toward the left passage 18b toward the downstream edge 38a. This is the same when viewed in the intake passage axial direction as shown in FIG. And
In this embodiment, the position of the downstream opening of the intake guide groove 38 is determined by the intake passage 31 in the valve and the intake port 1 on the downstream side.
8 when viewed from the upstream side, the left passage 18b and the central passage 1
This position is located on the left passage 18b side with respect to the partition wall 39 between the intake port 8a and the left passage 18b (see FIG. 6), and is located at a position facing the intake introduction groove 18e in the intake port 18. A concave groove 28a is formed in a portion of the valve body 28 corresponding to the opening on the downstream side of the intake guide groove 38 so that intake air can easily enter the intake introduction groove 18e from the intake guide groove 38. For this reason, when the valve body 29 is fully closed, the valve intake passage 31
The passage itself is also biased to the side of the side wall.

That is, when the valve element 29 rotates to the fully closed position, the intake air passes through the fully-closed ventilation space S and is biased toward the top wall 31b of the in-valve intake passage 31 and the top wall 18g of the intake port 18. Will flow. In addition, at this time, the intake air passing through the fully closed ventilation space S is larger than the space formed by the gap G in the intake guide groove 38 and the top wall 31.
6 and 8 flows in the space between the valve body 29 and the valve body 29 in the axial direction of the valve body 29 (FIGS. 6 and 8).
At the left). In other words, the left passage 18b of the intake port 18 and the intake introduction groove 1
More intake air flows to the 8e side.

In this embodiment, an example is shown in which the intake air flows also into the space formed by the gap G in the fully closed state. However, the gap G is narrowed to mainly reduce the intake guide groove 38 and the top wall 31b. It is also possible to configure so that the intake air mainly flows between the spaces. With this configuration, the amount of intake air flowing into the left passage 18b is further increased.

As shown in FIGS. 2 and 3, a fuel injection hole 41 is formed in the top wall 31b of the valve body 28 so as to open to the inner surface of the top wall for each intake passage. The fuel injection valve 30 is mounted on each of the fuel injection holes 41. One common fuel supply rail 30a extending in the cam axis direction is mounted on the upper end of the fuel injection valve 30. The fuel supply rail 30a is provided with a boss 23a formed integrally with the junction 23 of the intake manifold 21.
Bolts.

The fuel injection holes 41 are directed to the left and right intake valve openings 11b and 11c as shown in FIG. 2 when viewed from the side. When viewed from a plane, as shown in FIG. 6, it is located on the axis of the intake passage 31 in the valve.
It expands conically toward the right intake valve openings 11b and 11c. The fuel injection valve 30 is of a type having two injection ports, and each injection port has left and right intake valve openings 11b, 11b.
As shown by the broken line in FIG. 6, the fuel is conically injected toward c.

The fuel injection valve 30 may be disposed on the bottom wall side of the intake passage. In such a case, the intake passage can be made to rise more toward the cylinder shaft.
Inhalation resistance can be reduced. In addition, it is possible to connect a carburetor to the upstream end face of the valve body 28. In this case as well, the unit around the intake control valve can be united, and the assemblability can be improved.

In this embodiment, the following configuration is adopted in order to arrange the valve unit 20 closer to the intake valve openings 11a to 11c and to more surely control the drift of the intake flow by the valve unit 20. are doing. As shown in FIG. 2, the axis P of the spark plug 42 is inclined outward of the bank (exhaust valve side) by θ1 with respect to the cylinder axis H, and the angles θ2, θ2 of the intake valves 12a, 12b with respect to the cylinder axis H are accordingly adjusted. θ3 is the angle θ4 of the exhaust valve 14 with respect to the cylinder axis H.
Then, the intake valves 12a and 12b are made to stand closer to the cylinder axis H. Due to the upright arrangement of the intake valves 12a and 12b, the distance from the cylinder axis H to the exhaust camshaft 15 is L1, whereas the distance from the cylinder axis H to the intake camshaft 13 is reduced to L2. As a result, the external connection surface 18f inside the bank of the cylinder head 5 is made as small as possible with the intake valve openings 11a to 11c.
The valve unit 20 and, consequently, the valve body 29 are brought close to the intake valve openings 11a to 11c.

Further, by the above-described arrangement of the intake valves 12a and 12b and the arrangement of the intake camshaft 13 on the cylinder center side, it is possible to arrange the fuel injection valve 30 so as to be more upright. The upstream edge 41a of the opening of the hole 41 into the in-valve intake passage 31 can be positioned further downstream. In this embodiment, the axial position of the upstream edge 41a and the downstream edge 38a of the intake guide groove 38 are made substantially coincident with each other by the upright arrangement of the fuel injection valve 30. Accordingly, the fuel injection hole 41 is opened in the intake passage, thereby preventing the drift of the intake flow from being hindered.

If a sufficient space for arranging the fuel injection valve cannot be secured on the inner wall surface of the bank of the cylinder head, the fuel injection valve must be disposed inside the bank, that is, on the upstream side of the intake passage. In this case, even if the valve element is disposed on the downstream side, the above-described upstream edge 41a shifts to the upstream side from the downstream edge 38a of the intake guide groove 38, and the wall surface facing the downstream edge 38a As a result, the drift action of the intake flow by the valve element 29 is hindered.

Next, the operation of the present embodiment will be described. Engine speed 2600 rpm or less, throttle opening 20
%, The valve body 29 rotates to the fully closed position shown in FIG. 2 and FIG. 6 in the operating range where the intake air amount is relatively small at low speed rotation and low load of about% or less (low intake air amount operation range). The passage length switching valve 26 (see FIG. 1) closes the short passage 25. At this time, the intake air is introduced into the cylinder bore 2d from the surge tank 22 through the long passage 24, the in-valve intake passage 31, and the intake port 18. In this case, intake is performed by the valve 2
9 and the top wall 31b of the in-valve intake passage 31 through the fully closed ventilation space S, whereby the top wall 31b of the in-valve intake passage 31 and the intake port 1
8 flows toward the top wall 18g side, and also flows toward the left passage 18b and the intake introduction groove 18e, which are continuous with the left intake valve opening 11b, and is mainly introduced into the cylinder bore 2d from the left intake valve opening 11b.

To explain conceptually the above-mentioned biased state of the intake air flow, as for the vertical deviation of the intake passage, as shown by six arrows in FIG.
It flows unevenly to the 18g side. On the other hand, as for the bias in the width direction of the intake passage, as indicated by the six arrows in FIG. 6, most of the intake air passes through the space between the intake guide groove 38 and the top wall 31b, so that the left passage 18b And the intake groove 18e
Partially flows toward the central passage 18a and the right passage 18c through a space (gap G) between the outer peripheral surface of the valve portion 29a and the top wall 31b. As a result, the intake air amounts to the left, center, and right intake valve openings 11b, 11a, 11c are large, small,
It is a small percentage.

As described above, in this embodiment, the intake air flow is deflected toward the top wall of the intake passage and is deflected toward the left intake valve opening 11b.
When viewed in the camshaft direction, it flows in the vertical direction from the cylinder center side,
It has a tendency of a so-called tumble flow, and flows along the inner circumferential surface of the cylinder bore 2d as shown by a two-dot chain line arrow a in FIG. In the swirl flow, the intake air is supplied to the left intake valve opening 11b.
It is generated extremely strongly due to the inflow from the air inlet groove 18e.

As a result, as indicated by a two-dot chain line arrow b in FIG. 2, the intake air flow from the left intake valve opening 11b flows obliquely so as to become lower toward the right intake valve opening 11c. In the embodiment, a so-called oblique swirl flow is generated in the cylinder bore 2d as if the tumble flow and the swirl flow were combined. In addition, the intake resistance at this time gradually approaches the top wall 31b as the intake guide groove 38 moves from the upstream side to the downstream side, and the opening width gradually narrows as the opening width goes from the upstream side to the downstream side. It is extremely small because of the structure for flowing air. That is, the intake noise generated when the intake air flows through the intake guide groove 38 can be reduced. Moreover, turbulence is unlikely to occur on the downstream side of the intake guide groove 38, and the intake air flows smoothly, so that the flow rate of the intake air can be secured.

The fuel from the fuel injection valve 30 is
As indicated by broken lines in FIG. 6, the left and right intake valve openings 11b,
Injected toward 11c. Therefore, the cylinder bore 2
Looking at the concentration of the mixture introduced into d,
The concentrations of the air-fuel mixture from the left and center intake valve openings 11c, 11b, 11a are high, medium, and small, respectively.

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

Here, when the valve body 29 is rotated to the fully closed position, the valve body 29 has an intake resistance, so that there is a concern that the intake amount is insufficient. On the other hand, in the present embodiment, in the low-speed / low-load region, the switching valve 26 of the intake passage length is used to switch to the long passage 24 having a length at which the inertial supercharging effect can be obtained in this operation region. For this reason, due to the inertial supercharging effect due to the intake passage length, it is possible to compensate for the shortage of the intake air amount due to the intake resistance of the valve body 29, and to secure a necessary intake air amount.

When the engine speed is, for example, 2600
At 4600 rpm, in a medium speed rotation / medium load region where the throttle opening is, for example, about 40%, the valve element 29 is rotated to the fully open position. That is, as shown in FIG. 3, the portion of the valve body 29 that closed the intake passage at the time of full closing is immersed in the bottom wall 31 a, and the cutout surface 29 d forms a continuous surface with the inner surface of the in-valve intake passage 31. Become. As a result, there is no longer any resistance in the intake passage, so that the intake resistance can be eliminated and a necessary intake amount can be secured.

When the engine speed is, for example, 4600
rpm, and in a high-speed rotation / high load region where the throttle opening is substantially fully open, the passage length switching valve 26
Open 5. As a result, most of the intake air passes through the short passage 25 having a length that can provide an inertial supercharging effect in the high-speed rotation region, and the remainder is introduced into the long passage 24 into the cylinder. Is done.

Also, in this embodiment, the valve unit 20 is disposed upstream of the branching point in the cylinder axis direction of the central passage 18a and the left and right passages 18b, 18c constituting the intake port 18. In particular, the structure of the valve body 29 can be simplified, and the diameter of the valve body 29 can be minimized.
By the way, when it is located downstream from the branch start part,
It is necessary to make the outer shape and the notched surface shape of the valve body correspond to, for example, the cross-sectional shape of the passage shown in FIG. 11, and the shape becomes extremely complicated and the diameter becomes large.
On the other hand, the valve body 29 of this embodiment need only form a simple elliptical cut surface 29d in a simple columnar body, and has a simple shape and a small diameter.

Further, in this embodiment, since the spark plug 42 is inclined toward the exhaust side and the intake valves 12a, 12b are raised, the intake camshaft 13 is arranged closer to the cylinder center. A space is provided on the intake side, and the valve unit 20 can be arranged on the upstream side of the above-described branch start portion and closer to the intake valve openings 11a to 11c. As a result, the controllability of the intake air flow can be improved while simplifying the above-described valve structure. That is, when the intake control valve having the structure of this embodiment is provided, the more the valve body 29 is away from the opening of the intake valve, the more the drift toward the ceiling wall side is diffused. By adopting such an arrangement structure, the valve element 29 can be brought close to the intake valve opening.

Further, in this embodiment, the valve unit 20, which is a unit of the valve body 28, the valve element 29, the fuel injection valve 30, and the driving servomotor 37, is attached to the external connection surface 18f of the cylinder head by the mounting bolt 27. Since it is detachably mounted, machining and assembly around the cylinder head in the case of an engine having a large number of cylinders is easy. For example, when a structure in which the valve body is directly inserted into the cylinder head is adopted, the number of man-hours for manipulating the cylinder heads 4 and 5 both having large weight and volume increases, so that the burden on machining and assembly increases. 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. In this case, the number of manufacturing steps can be reduced.

In this embodiment, an example is shown in which the intake guide groove is configured to flow the intake air to one of the three intake passages. It can also be configured to flow. In this case, another intake guide groove which is symmetrical to the present embodiment is added to the valve body. Further, in this embodiment, an example is shown in which the cylinder heads 4, 5 and the valve body 28 are formed separately, but they may be formed integrally. In this case, the valve body 29 is rotatably fitted to the cylinder heads 4 and 5. Furthermore, in the present embodiment, the fuel injection device 3
Although an example in which the fuel is injected in two directions as 0 is shown, the fuel injection direction can be changed as appropriate. For example, a structure in which fuel is injected from one fuel injection port into all three intake passages may be used.

In addition, in this embodiment, an example is shown in which the valve body is formed in a columnar shape and is rotated inside the valve body. However, the valve body is configured as shown in FIGS. 12 and 13. You can also. FIG. 12 is a cross-sectional view showing another embodiment in which the valve element is configured to be movable in parallel with the intake passage in the valve. FIG. 13 is configured so that the valve element is swingable so as to protrude and retract from the intake path in the valve. FIG.
In these figures, the same or equivalent members as those described in FIGS. 1 to 11 are denoted by the same reference numerals, and detailed description thereof will be omitted.

The valve body 51 shown in FIG. 12 is formed in a substantially plate shape, and the drive shaft 52 connected to the lower end is moved in parallel by an actuator (not shown) in the direction shown by the arrow in FIG. It is structured to open and close. The valve body 53 shown in FIG. 13 is also formed in a substantially plate shape, and is pivotally supported by the valve body 28 via a support shaft 54 driven to rotate by an actuator (not shown).

As shown in FIGS. 12 and 13, by projecting the valve bodies 51 and 53 into the in-valve intake passage 31, the intake air can be biased toward the top wall 31b. At the time of full opening, each valve element 51, 53 is immersed in the valve body 28 as shown by a two-dot chain line in the figure. 55 is a cover for closing the valve housing space. Even with this configuration, the intake air can be biased toward the top wall side of the intake passage, so that a tumble can be generated in the cylinder.

[0065]

As described above, the intake control apparatus for an engine according to the first aspect of the present invention is provided with a valve body for an intake control valve having an intake passage in a valve communicating with the intake passage of the cylinder head. The intake passage in the valve is formed in a shape corresponding to the cross-sectional shape of the intake passage of the cylinder head, and the bottom wall of the intake passage in the valve is moved to the top wall side in the closed state in the valve body. The valve body for biasing the flow toward the top wall is provided, and the valve body is provided with a closed-state intake guide groove for directing the intake flow toward at least one of the axial directions of the intake camshaft. When moved toward the wall, the intake air flow is deviated toward the top wall side of the intake passage in the valve, and flows into the cylinder in the vertical direction from near the center of the cylinder, causing tumble. Further, when the bottom wall of the in-valve intake passage is moved toward the top wall, the intake air flow is deviated to one of the top wall side and the cam shaft direction of the in-valve intake passage. Therefore, a tumble is generated in the cylinder and a swirl composed of a swirling flow around the cylinder axis is also generated. Therefore, there is an effect that the combustion state of the engine can be improved. In addition, since the amount of generation of tumble and swirl increases and decreases according to the degree of opening of the valve element, there is an effect that both tumble and swirl can be simultaneously controlled by a simple configuration. Also, since the valve element moves the bottom wall of the intake passage in the valve to the top wall side and becomes closed,
Even in the closed state, the intake resistance is small. For this reason, even when the valve element is in the closed state, the intake resistance is small, so that intake noise can be suppressed low.

The engine intake control device according to a second aspect of the present invention is the same as the engine intake control device according to the first aspect, except that the valve body is formed separately from the cylinder head. Since the valve unit is mounted on the cylinder head, machining for arranging the intake control valve on the cylinder head having a large weight and a large volume can be minimized.
The valve unit itself is relatively lightweight and small, and can be so-called sub-assembly in another production line. Therefore, the production and assembly is easier than in the case where the valve body is directly mounted on the cylinder head.

[0067]

[0068]

An intake control system for an engine according to a third aspect of the present invention is the intake control system for an engine according to the first or second aspect of the present invention, wherein three intake valves are provided and the intake passage of the cylinder head is formed by an intake valve. Adopts an engine that is branched for each intake valve in the vicinity, and the downstream end of the intake guide groove is located at the shaft end side of the intake camshaft among the three intake passages as viewed from the upstream side of the intake flow. Since the intake passage is located closer to the side intake passage than the partition wall between the passage and the central intake passage, the intake air that has passed through the closed-state intake guide groove mainly flows into the side intake passage, so that swirl occurs in the cylinder. The tendency increases.

According to a fourth aspect of the present invention, there is provided an intake control apparatus for an engine according to any one of the first to third aspects, wherein the valve in the intake passage in the valve and the intake passage of the cylinder head is provided. Since the side wall on the intake guide groove side of the body is expanded to the side from the intake passage when the valve body is in the fully opened state, the intake air passing through the closed state intake guide groove passes through the expanded portion of the intake passage side wall. Since the valve body flows into the side intake passage from a side more than the inflow path when the valve body is fully open, swirl is easily generated in the cylinder.

According to a fifth aspect of the present invention, there is provided an intake control system for an engine according to any one of the first to fourth aspects, wherein the intake guide groove of the valve element is provided at a position downstream from the upstream end. Since the width is gradually reduced toward the end, the resistance when the intake air passes through the closed-state intake guide groove is reduced, and the intake resistance is further reduced. For this reason, intake noise can be suppressed as small as possible. In addition, since turbulence is unlikely to occur downstream of the closed-state intake guide groove and the intake air flows smoothly, the flow rate of the intake air can be ensured.

According to a sixth aspect of the present invention, there is provided an intake control apparatus for an engine according to any one of the first to fifth aspects, wherein a valve element is partially formed at the bottom of the intake passage in the valve. The valve body is formed in a substantially cylindrical shape so as to be immersed in the wall, and is supported by the valve body so as to be rotatable around the cam axis direction. The valve body has a notched surface corresponding to the cross-sectional shape of the intake passage in the valve. The air intake guide groove for air intake and the closed air intake guide groove for biasing the intake air flow to the top wall side of the intake passage in the valve are formed, so a circular valve hole is formed in the valve body, and a valve element is inserted in this valve hole. By fitting, the intake control device is assembled. For this reason, manufacture is very easy.

[Brief description of the drawings]

FIG. 1 is a schematic front view showing an entire configuration of an engine including an apparatus according to an embodiment.

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

FIG. 3 is a cross-sectional front view of the device of the present embodiment in a fully opened state.

FIG. 4 is a bottom view of the apparatus of the present embodiment.

FIG. 5 is a side view of the valve unit.

FIG. 6 is a sectional view taken along line VI-VI in FIG. 2;

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

FIG. 8 is a view showing a state where the valve body is rotated to a fully closed position, and is a sectional view taken along line VIII-VIII in FIG. 2;

FIG. 9 is a view showing a state in which the valve body is turned to a fully open position, and is a sectional view taken along line IX-IX in FIG. 3;

FIG. 10 is a sectional view taken along line XI-XI in FIG. 6;

11 is a sectional view taken along line XII-XII in FIG. 6;

FIG. 12 is a cross-sectional view showing another embodiment in which the valve body is configured to be movable in parallel with respect to the intake passage in the valve.

FIG. 13 is a cross-sectional view showing another embodiment in which a valve body is configured to be swingable so as to protrude and retract from an intake passage in the valve.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Engine, 2d ... Cylinder bore, 4, 5 ... Cylinder head, 12a, 12b ... Intake valve, 13 ... Intake camshaft,
14: exhaust valve, 15: exhaust camshaft, 18: intake port,
Reference Signs List 20: valve unit, 28: valve body, 29: valve body, 29a: valve portion, 29d: notched surface, 30: fuel injection valve, 31: intake passage in valve, 31a: bottom wall, 31b ...
Top wall, 38: intake guide groove, 51, 54: valve body.

Claims (6)

(57) [Claims] An intake control valve valve body having an in-valve intake passage communicating with an intake passage of a cylinder head is provided in a cylinder head, and the in-valve intake passage corresponds to a cross-sectional shape of the intake passage of the cylinder head. and forming a shape, this valve body, the valve body to bias the top wall side of the intake flow of the bottom wall is moved to the top wall side of the intake passage in the valve is provided in the closed state, the intake to the valve body Intake flow
The intake air for the closed state is directed to at least one of the axial directions of the
An intake control device for an engine, comprising an id groove . 2. The intake control device for an engine according to claim 1, wherein the valve body is formed separately from the cylinder head. 3. An intake control system for an engine according to claim 1, wherein the engine is provided with three intake valves and an intake passage of a cylinder head is branched for each intake valve in the vicinity of the intake valve. The downstream end of the intake guide groove is located closer to the partition between the side intake passage located at the shaft end side of the intake camshaft and the central intake passage when viewed from the upstream side of the intake flow. An intake control device for an engine, wherein the intake control device is located on a side of a part intake passage. 4. The method according to claim 1, wherein
In the intake control devices for the two engines, the side walls on the valve body intake guide groove side in the intake passage in the valve and the intake passage of the cylinder head are expanded to the side from the intake passage when the valve body is in a fully opened state. Characteristic engine intake control device. 5. The intake control device for an engine according to any one of claims 1 to 4 , wherein the intake guide groove of the valve body is formed so as to become gradually narrower from the upstream end to the downstream end. An intake control device for an engine, comprising: In the intake control device of any one engine of the 6. The method of claim 1 to claim 5, a portion of the valve body is formed in a substantially cylindrical shape that retracted into the bottom wall of the intake passage in the valve The valve body is rotatably supported around the cam axis direction, and the valve body has a fully open intake guide groove consisting of a cutout surface corresponding to the cross-sectional shape of the intake passage in the valve, and intake air in the valve. An intake control device for an engine, wherein a closed-state intake guide groove biased toward the top wall of the passage is formed.