JPH0666148A - Intake controller for engine - Google Patents

Abstract

PURPOSE:To provide an intake controller for an engine which can surely generate a longitudinal swirl by suppressing the disturbance of an intake air stream and can eliminate the trouble of increase of intake resistance in a high speed revolution, and suppresses the increase of cost by improving the installation performance of a partitioning plate. CONSTITUTION:As for an intake controller, an intake control valve 21 for allowing the intake air to flow in deflection to a top wall 17f side positioned on the head cover joint surface 4i side of an intake passage 17 by drawing the bottom wall side part of the intake passage 17 in case of the low intake air quantity is arranged in turnable manner in the bottom wall 17d positioned on the cylinder block joint surface 4a side of the intake passage 17 of a cylinder head 4. Further, a partitioning part 20 for dividing the inside of the passage 17 to a top wall side part C and a bottom wall side part D is installed at the downstream side part from the intake control valve 21 in the intake passage 17, and the partitioning part 20 is formed integrally with the cylinder head 4.

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 in which the intake passage area is controlled by an intake control valve, and more particularly, it improves combustion stability in a state where the intake air amount is small, and particularly The present invention relates to a structure capable of improving the fuel efficiency in a low / medium-speed / low-load range operating range, and improving partition plate mountability to suppress an increase in cost.

[0002]

2. Description of the Related Art In order to improve the fuel efficiency of an engine, it is possible to stabilize the combustion at a lean air-fuel ratio by generating a vertical vortex (tumble) in the combustion chamber by increasing the flow velocity even when the intake air amount is small. It is known to be effective. As an intake control device capable of generating such a tumble, the present applicant has arranged an intake control valve that narrows down the bottom wall side portion of the intake passage at the time of a low intake air amount, and also the intake control valve downstream side portion of the intake passage. We have proposed an intake control device that is equipped with a partition plate that divides the space into a top wall side portion and a bottom wall side portion (see Japanese Patent Application No. 3-360129). According to this proposed device, even if the intake air amount is small, it is possible to reliably generate the tumble by giving the intake flow a directionality that flows vertically in the cylinder axis direction.

[0003]

By the way, in the intake control device according to the above-mentioned proposal, as a structure for mounting the partition plate in the intake passage, a retaining ring is integrally formed at the downstream end of the partition plate, and the retaining ring is formed. It uses a cantilevered structure that holds the ring between the valve seats. However, in such a structure, the rigidity and mounting strength of the partition plate itself may be insufficient depending on how the length of the partition plate is set. There is also a problem that the number of mounting steps increases, and improvements in these points are required.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an intake control device for an engine which can improve the rigidity and mounting strength of the partition plate itself and can reduce the number of mounting steps.

[0005]

Therefore, according to the invention of claim 1, the intake air is drawn into the bottom wall of the intake passage of the cylinder head by narrowing down the bottom wall side portion of the intake passage when the intake air amount is low. The intake control valve that is biased to the top wall side is rotatably disposed, and a partitioning portion that divides a portion of the intake passage downstream of the intake control valve into a top wall side portion and a bottom wall side portion is provided. An intake control device for an engine, which is formed integrally with a cylinder head.

According to the second aspect of the present invention, a partition plate is provided in the intake control valve so that the partition plate can be retracted and retracted, and when the intake control valve is rotated to the fully closed position, the partition plate is projected so that the inside of the intake passage is raised. It is characterized in that it is divided into a wall side portion and a bottom wall side portion, and provided with a retracting drive means for retracting the partition plate into the intake control valve when it is rotated to the fully open position.

Here, as a method of integrally forming the partition portion on the cylinder head, for example, when casting the cylinder head, a space corresponding to the partition portion along the mold split surface of the shell core forming the intake passage is formed. It is possible to adopt a method of integrally casting by providing a (cavity) and pouring molten metal into the space.

[0008]

According to the engine intake control device of the first aspect of the present invention, when the intake air amount is small, the intake control valve narrows down the bottom wall side portion of the intake passage, and the partition portion is downstream of the intake control valve. Since the side is divided into the top wall side portion and the bottom wall side portion, the sucked air flows unevenly toward the top wall side portion having a small passage area and the speed thereof rises. As a result, the intake airflow flowing into the cylinder is given a vertical directionality that flows in the cylinder axial direction, and as a result, tumble occurs and lean combustion is stably performed. Further, when the intake air amount is high, the intake control valve rotates to the fully open position, so that the intake control valve does not stay in the intake passage, and an increase in intake resistance can be avoided.

Further, since the partition portion is formed integrally with the cylinder head, the rigidity of the partition portion itself and the strength in the arranged state can be greatly improved as compared with the case of the cantilever support structure of the proposed device. Especially, there are no restrictions on the length of the partition,
The intake control valve can be arranged at any position.

Further, it is possible to eliminate the troublesome work such as the case where the partition plate which is the above-mentioned separate component is retrofitted, and it is possible to reduce the number of components and the manufacturing cost.

According to the second aspect of the present invention, the partition plate is provided in the intake control valve so as to be retractable, and the partition plate is projected when the intake control valve is rotated to the fully closed position. Since it is only necessary to attach it, in the case of the present invention as well, troublesome attachment work can be eliminated. Further, since the partition plate is retracted into the intake control valve when the partition plate is rotated to the fully open position, it is possible to avoid the problem of increase in intake resistance due to the partition plate.

[0012]

Embodiments of the present invention will be described below with reference to the accompanying drawings. 1 to 3 are views for explaining an intake control device for an engine according to an embodiment of the present invention.

In the figure, reference numeral 1 is a water-cooled 4-cycle 4-valve engine, in which a cylinder block 3 and a cylinder head 4 are stacked on a crankcase 2 and fastened with head bolts, and the cylinder head 4 is attached to the head cover side. The head cover 5 is attached to the surface 4i. A piston 7 is slidably inserted into a cylinder bore 3a formed in the cylinder block 3, and the piston 7 is connected to a crankshaft (not shown) by a connecting rod 8.

On the cylinder block side mating surface 4a of the cylinder head 4, there is formed a combustion recess 4b which constitutes a combustion chamber. The combustion recess 4b has two intake valve openings 4c and two exhaust valve openings 4d. At each exhaust valve opening 4d, the valve head 10a of the exhaust valve 10 is
The valve heads 11a of the intake valves 11 are arranged in the intake valve openings 4c so that the respective openings can be opened and closed. The valve stems 10b and 11b of the exhaust and intake valves 10 and 11 extend obliquely upward in the cylinder axis direction so as to form a predetermined included angle when viewed in the cam axis direction, and the exhaust and intake lifters 12, 13 are mounted respectively. Further, exhaust and intake cam shafts 14 and 15 for pressing and driving the lifters 12 and 13 are arranged in a direction perpendicular to the cylinder axis and parallel to each other. In addition, 12a and 13a are valve springs for urging each valve in the closing direction, and 29 is an ignition plug.

The two exhaust valve openings 4d are led out to the front wall 4f side of the cylinder head 4 by a bifurcated exhaust passage 16, and an exhaust pipe (not shown) is provided in the wall opening 16a of the exhaust passage 16. It is connected. In addition, each intake valve opening 4c
Are led out to the rear wall 4g side of the cylinder head 4 by the intake passages 17, respectively. The intake passages 17 are parallel to each other when viewed in the cylinder axis direction, and when viewed in the cam axis direction, after being bent in an arc shape from the intake valve opening 4c to the cylinder rear wall 4g side, they are substantially linear. It is extended. A common cab joint 18 is connected to each wall surface opening 17a of each intake passage 17, and the joint 18
It merges into one passage inside. One carburetor 19 is connected to the cab joint 18. The carburetor 19 is an automatic variable venturi type having a butterfly type throttle valve 19a which is opened and closed by a throttle operation and a piston valve 19b which is automatically opened and closed by an intake negative pressure of the engine.

A switching valve 26 is arranged in the cab joint 18. The switching valve 26 includes a valve shaft 26a arranged to penetrate the joint 18 in parallel with the cam shaft direction, and a valve plate 26b fixed to the valve shaft 26a and opening / closing the one intake passage 17. It is configured.

The upstream straight portion 17b of each of the intake passages 17
A valve hole 17c is formed therethrough in the cam shaft direction.
The axis of the valve hole 17c is the bottom wall 1 of the intake passage 17
Located in the vicinity of the surface of 7d, the inner portion of the intake passage 17 is formed in a substantially semicircular shape, and connects two adjacent intake passages for cylinders. Each intake passage 17 is provided in the valve hole 17c.
An intake control valve 21 for changing the passage cross-sectional area is inserted and arranged. The intake control valve 21 is formed by forming a valve portion 21a that opens and closes each intake passage 17 by cutting a part of a round bar so as to form a continuous surface with a lower inner surface of the intake passage 17. Fully open position where the portion 21a is recessed in the valve hole 17c and is flush with the inner surface of the intake passage (see FIG. 2)
And the valve portion 21a is erected substantially vertically from the surface of the bottom wall 17d so as to be rotatable between a fully closed position (see FIG. 1) in which the intake passage 17 is narrowed to approximately 1/2. In this case, the valve portion 21a is rotated so that the outer peripheral surface thereof is located on the upstream side.

A control pulley 22a is fixed to the outer end of the intake control valve 21, and the control pulley 22a is connected to a drive pulley 22b fixed to a control motor by a cable. A switching pulley 26c is fixed to the outer end of the switching valve 26, and the switching pulley 26c is connected to a drive pulley 26d fixed to the switching motor by a cable. The control motor and switching motor are ECU
The rotation is controlled by 23. This ECU 23
Is inputted with the opening signal a of the throttle valve 19a from the throttle opening sensor 24 and the engine rotation speed signal b from the rotation sensor 25, and the intake control valve 21 is
A control signal A for rotating to the fully closed position side as the intake air amount is smaller as in the low / medium speed / low load operating range, and to the fully open position side as the intake air amount is larger as in the high / high load operating range.
Is output to the control motor, and the control valve B is output to the switching motor so that the switching valve 26 is closed when the intake air amount is equal to or less than a predetermined value and is opened when the intake air amount exceeds the predetermined value.

A partition section 20 is provided on the downstream side of each intake passage 17 from the intake control valve 21. This partition 2
The reference numeral 0 extends along a substantially center line of the intake passage 17, and its upstream end 20a faces the upper end of the valve portion 21a of the intake control valve 21 located at the fully closed position, and has a substantially continuous surface with this. It's designed to be eggplant. The downstream end portion 20c is located immediately upstream of the intake valve opening 4c. Thus, the partition 20a divides the intake passage 17 into the top wall 17f side portion C and the bottom wall 17d side portion D. Reference numeral 20b is a relief portion that avoids interference with the valve stem 11b of the intake valve 11.

The partition 20 is integrally cast with the cylinder head 4 by the following method. That is, the partitioning portion 20 makes the mold splitting surface of the shell core forming the intake passage 17 of the cylinder head 4 along the center line of the passage 17 when casting the cylinder head 4, and the space between the splitting surfaces. It is formed by forming a cavity corresponding to the partition 20 and pouring the cavity into the cavity.

Next, the function and effect of this embodiment will be described. In an operating region in which the intake air amount is small, such as at low to medium speeds and low loads, the control signal A from the ECU 23 causes the control motor to rotate the intake control valve 21 to the fully closed position shown in FIG. The control signal B causes the switching motor to rotate the switching valve 26 to the closed position shown in FIG. Then, the valve portion 21a of the switching 21 is connected to the bottom wall 17d of each intake passage 17.
One side of the intake passage 17 is fully closed by narrowing down the side and by the switching valve 26. As a result, the intake air concentrates on the other side of the intake passage 17 having no switching valve, and flows toward the top wall side portion C of the passage 17 which is divided by the partition portion 20, and the intake air on the other side of the intake passage 17 enters the cylinder. It flows in only from the intake valve opening 4c. As a result, even if the intake air amount is small, the flow directionality is obtained, and when viewed in the cylinder axis direction, it flows laterally along the inner surface of the cylinder, and when viewed in the cam axis direction, it flows diagonally in the vertical direction along the cylinder axis. Tumble occurs (→ in Fig. 1)
See the mark).

As described above, in the present embodiment, the switching valve 26 is provided which causes the intake air to flow concentratedly to the other passage 17 side by closing the one intake passage 17, and the intake air is passed through the passage 1
7 is provided with an intake control valve 21 that is biased toward the top wall 17f side, and the intake passage 17 is further provided with a top wall side portion C and a bottom wall side portion D.
Since the partitioning section 20 that divides the intake air is provided, when the intake air amount is small, the intake air can flow from one intake valve opening along the inner surface of the cylinder and in the axial direction of the cylinder with directionality. It is possible to generate an oblique tumble that is a combination of tumble and tumble. As a result, lean combustion can be stabilized and the fuel consumption rate can be improved.

Further, in this embodiment, since the partition 20 is integrally cast on the cylinder head 4, the number of working steps and the number of parts can be reduced as compared with the case where a partition plate of another component is attached, and the manufacturing cost is reduced accordingly. it can. In this case, since the partition part 20 only needs to form a cavity between the mold split surfaces of the shell core, the cost increase can be suppressed also from this point. Further, since the partition portion 20 is integrally formed, it is possible to eliminate a gap between the both end edges of the partition plate and the inner surface of the intake passage when the partition plate is attached separately.
Leakage of intake air can be prevented.

Further, in this embodiment, the intake control valve 21
Is provided at a position distant from the valve head 11a, the influence of combustion heat on the control valve 21 can be suppressed. in this case,
Although the inner length of the passage of the partition 20 will be increased,
In this embodiment, since it is integrally cast, there is no problem in strength due to the lengthening. In the case of a partition plate which is a separate component, since it is supported in a cantilever manner, there is a problem that the longer it is, the lower the holding strength and the rigidity of the partition plate itself, but this embodiment can solve this problem.

4 to 8 are views for explaining an intake control device according to an embodiment of the present invention. In the figure, the same reference numerals as those in FIGS. 1 and 2 indicate the same or corresponding portions. A valve hole 17c is formed in the bent portion 17h of the intake passage 17 near the intake valve opening. A valve portion 3 for changing the passage area of each intake passage 17 is provided in the valve hole 17c.
An intake control valve 30 having 0a is rotatably inserted and arranged, and the intake control valve 30 is pivotally supported by a drive cylinder 32 that is inserted and fixed to the cylinder head 4. A partition 33 is provided downstream of the intake control valve 30 in the intake passage 17, and the partition 33 is integrally cast on the cylinder head 4.

A storage groove 30b extending in the axial direction of the intake control valve 30 is formed in the intake control valve 30. This storage groove 30b
A strip plate-shaped partition plate 31 is disposed inside so that it can be retracted, and is biased by a biasing spring 34 so as to project outward. A cam portion 31a is formed at the end of the partition plate 31, and the cam portion 31a is inserted into a cam groove 32b formed in the bearing portion 32a of the drive cylinder 32. The cam groove 32b coincides with the storage groove 30b when the intake control valve 30 is rotated to the fully closed position, allows the partition plate 31 to project, and moves the cam portion 31a as it rotates to the open side. The partition plate 31 is depressed by pressing.

In this embodiment, when the intake control valve 30 is rotated to the fully open position, the storage groove 30b is moved to the cam groove 32.
b, the partition plate 31 is pushed out by the biasing spring 34, and protrudes outward to form a substantially continuous surface with the partition part 33.
The intake passage 17 is divided into a top wall side portion C and a bottom wall side portion D (see FIGS. 8B and 4). When the intake control valve 30 is rotated to the fully open position, the cam portion 31a is pushed inward by the cam groove 32b, whereby the partition plate 31 is stored in the storage groove 30b and the valve portion 30a is moved to the intake passage 17.
Is flush with the inner surface of the sheet (see FIGS. 8 (a) and 5).

According to this embodiment, the partition plate 31 is provided in the intake control valve 30 so as to be retractable, and the partition plate 31 is projected when the intake control valve 30 is fully closed so that the intake passage 17 is located at the top wall side C and the bottom. Since it is divided into the wall side D, turbulent flow can be prevented and tumble can be surely generated, and since only the intake control valve 30 needs to be assembled, there is no need to separately install a partition plate. You can Further, since the partition plate 31 is housed in the housing groove 30b when the intake control valve 30 is fully opened, an increase in intake resistance due to the partition plate can be suppressed.

In each of the above embodiments, a switching valve for opening and closing any of the intake passages is provided, but this switching valve is not always necessary in the present invention, and it goes without saying that an engine having only one intake passage will be required. Applicable. Further, in the above-mentioned embodiment, the case where the invention is applied to the engine for motorcycle is explained as an example, but the present invention can be applied to the engine for automobile as well.

[0030]

As described above, according to the intake control device for an engine of the present invention, the intake control valve for narrowing down the bottom wall side portion of the intake passage is provided when the intake air amount is low, and the intake passage Since the partition portion for partitioning the downstream side portion of the intake control valve into the top wall side portion and the bottom wall side portion is provided, and the partition portion is integrally formed with the cylinder head, according to the invention of claim 2, the intake control valve is partitioned. Since the plate is retractable, the partition plate is projected when the intake control valve is fully closed, and the partition plate is retracted inside the intake control valve when it is fully open, so even if the intake air amount is small Can be given, and as a result, tumble can be reliably generated, lean combustion can be stabilized, and fuel consumption can be improved.

Further, according to the first aspect of the invention, the rigidity and the mounting strength of the partition plate itself can be improved, and the number of parts and the number of mounting steps can be reduced as compared with the case where the partition plate which is a separate component is mounted.

[Brief description of drawings]

FIG. 1 is a sectional side view showing an intake control device for an engine according to a first embodiment of the present invention.

FIG. 2 is an enlarged view of an intake control valve and a partition section of the first embodiment.

FIG. 3 is a sectional view of a partition portion of the intake passage of the first embodiment.

FIG. 4 is a sectional side view showing an intake control device according to a second embodiment of the invention of claim 2.

FIG. 5 is a sectional side view showing a storage state of the partition plate of the second embodiment.

FIG. 6 is a perspective view showing an intake control valve of the second embodiment.

FIG. 7 is a diagram showing a retracting mechanism of a partition plate according to the second embodiment.

FIG. 8 is a sectional side view showing a retracting mechanism of the second embodiment.

[Explanation of symbols]

 1 Engine 3 Cylinder Block 4 Cylinder Head 5 Head Cover 17 Intake Passage 17d Bottom Wall 17f Top Wall 20 Partition Part 21,30 Intake Control Valve 31 Partition Plate C Top Wall Side Part D Bottom Wall Side Part

Claims (2)

[Claims] 1. An intake control valve for causing intake air to flow toward a ceiling wall of an intake passage by narrowing a portion of the intake passage on the bottom wall side when the amount of intake air is low in the bottom wall of the intake passage. An intake control of an engine, characterized in that the cylinder head is integrally formed with a partitioning section that is arranged so as to be possible and divides a downstream side portion of the intake passage from the intake control valve into a top wall side portion and a bottom wall side portion. apparatus. 2. An intake control valve for turning intake air to flow toward the top wall of the intake passage by narrowing the bottom wall side portion of the intake passage into the bottom wall of the intake passage when the intake air amount is low. The intake control valve is provided with a partition plate so that the partition plate can be retracted and retracted, and when the intake control valve is rotated to the fully closed position, the partition plate is projected so that the inside of the intake passage is located on the ceiling wall side portion. An intake control device for an engine, characterized by being provided with a retractable drive means for retracting the partition plate into the intake control valve when the partition plate is divided into a bottom wall portion and a bottom wall side portion.