JPH08128327A - Low load time swirl generator of internal combustion engine - Google Patents

Abstract

PURPOSE: To form an excellent swirl by accelerating intake air flow speed at low load time, and enable application even to an existing internal combustion engine. CONSTITUTION: A low load time swirl generator 1 has two intake air passages of a main port 8 for a high load and a sub-port 5 for a low load, and in the sub-port 5, an intake air outflow port is formed smaller than an intake air inflow port, and a nozzle part of the sub-port 5 extending from a device main body is opened in the vicinity of an intake air port 7a of a combustion chamber 7, and a directional control valve 9 arranged in the main port 8 is closed at engine low load time.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a low-load swirl generator for an internal combustion engine, and more particularly to a device for accelerating an intake flow velocity at low engine load to effectively generate a swirl in a cylinder. It is a thing.

[0002]

2. Description of the Related Art It is well known that various proposals have been made for the structure of an intake passage, particularly an intake port, in order to generate a good swirl in a combustion chamber of an internal combustion engine and efficiently burn fuel. For example, in the intake device described in Japanese Patent Laid-Open No. 54-52220, a twist of 90 ° is inserted between the inlet on the carburetor side and the outlet on the combustion chamber side in the intake passage and the intake port on the downstream side of the carburetor. A partition wall is provided to partition the primary intake passage for a relatively small cross-sectional area for low load and the secondary intake passage for a relatively large cross-sectional area for high load to generate a flow swirling in the circumferential direction of the intake port. It was made to let.

However, the structure in which the partition wall twisted by 90 ° is formed in the intake passage and the intake port as described above has a problem that sufficient swirl cannot be obtained despite complicated processing. Therefore, the intake device described in Japanese Patent Laid-Open No. 58-148228 has a low load intake passage having a relatively small cross-sectional area and a high load intake passage having a relatively large cross-sectional area in the intake passage downstream of the carburetor. A switching valve that is partitioned by a partition wall and closes during low load operation is installed in the high load intake passage, and the outlet of the low load intake passage is biased to one side with respect to the center axis of the intake port, and the intake port turns in the circumferential direction. A guide groove is formed on the inner wall of the intake port so that the intake air flowing out from the low-load intake passage flows while swirling in the intake port (preferably a helical shape).

[0004]

By the way, the above-mentioned Japanese Patent Laid-Open No.
In the means described in Japanese Patent Laid-Open No. 8-148228, since the partition wall is not provided in the intake port, processing becomes easier, but
The problem that the flow velocity of the air-fuel mixture decreases in the intake port. When the intake valve opens and combustion gas flows backward from the cylinder into the intake port, the rectification effect of flowing the intake flow along the guide groove is significantly impaired. There is such a problem.

The present invention can accelerate intake air at low engine load and supply it to the combustion chamber to generate a good swirl, and can be applied to existing internal combustion engines as well. The purpose is to provide a generator.

[0006]

The structure of a low load swirl generator for an internal combustion engine according to the present invention for achieving the above object is attached to an intake port of the internal combustion engine to accelerate the intake flow velocity at low engine load. Which has two intake passages, a main port having a larger cross-sectional area for high load and a sub-port having a smaller cross-sectional area for low load, and the main port is closed during engine low load operation. A switching valve is installed to make the intake outlet area smaller than the intake inlet area of the subport, and the intake outlet of the subport is opened near the intake port of the combustion chamber.

As a means for reducing the area of the intake air outlet from the intake air inlet with the subport shape, it is preferable to gradually reduce the cross-sectional area toward the downstream side of the intake air because it reduces the flow resistance. The shape can be appropriately adapted to the actual situation, such as reducing the cross-sectional area from the middle. Further, the intake port of the sub-port is directed to a direction suitable for forming a swirl in the combustion chamber so as to provide a direction and a cut end from which the intake air blows.

The cross-sectional shape of the subport is not particularly limited, and may be an appropriate shape such as a circle, an oval shape, an oval shape, a rectangular shape with rounded corners, or a shape similar to these, in accordance with actual circumstances. be able to. Further, the cross-sectional shape on the upstream side and the cross-sectional shape on the downstream side may be different. The subports can remain open during high load operation. However, since the flow resistance of the sub port is much higher than that of the main port, most intake air is supplied to the combustion chamber through the main port during high load operation. Therefore, it is desirable that the main port is designed in advance so as to have a sufficiently large cross section so that flow resistance does not occur.

The low-load swirl generator for an internal combustion engine of the present invention is a device for accelerating the intake flow velocity at low engine load by being installed between the intake manifold and the intake port of the internal combustion engine. Of the main port having a larger cross-sectional area and a sub-port having a smaller cross-sectional area for low load, and two intake passages are provided. The intake outlet area may be formed smaller than the inlet area, and the intake outlet of the subport may be formed in a nozzle shape near the intake of the combustion chamber.

The nozzle-shaped portion of the sub-port (hereinafter referred to as the nozzle portion) may be formed separately from the apparatus main body, and may be assembled and assembled to form a unit. The separate nozzle part may be formed by sheet metal working of iron, aluminum or the like, precision casting, injection molding with resin, or the like, or the nozzle part may be divided into two and integrated when assembled. However, the material of the device of the present invention, the processing method, etc. are not particularly limited, and any means can be adopted. The internal combustion engine to which the low load swirl generator of the present invention is applied is mounted on a gasoline engine. It can also be mounted on a diesel engine.

[0011]

[Function] The intake port of the sub-port is made narrower than the cross-sectional area of the main port, and the area of the intake port of the sub-port is
The structure according to claim 1, wherein the intake air is made to be narrower than the intake air inlet of the sub-port so that the intake air flows out to the vicinity of the intake opening of the combustion chamber. It is made to flow from the intake port of the sub-port with a small area, and the intake port is further reduced to accelerate the intake flow velocity under a lower flow resistance, and to flow it out to the vicinity of the intake port of the combustion chamber, and to improve the intake in the combustion chamber. Acts to form a swirl.

A low load swirl generator having the above construction is
The structure according to claim 2, wherein the structure is provided between the intake manifold and the intake port, and the intake outlet of the sub-port extends into the intake port. -Maintenance cost can be reduced as much as possible, and it can be installed in an existing internal combustion engine.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the accompanying drawings. The first embodiment shown in FIGS. 1 and 2 is carried out for a gasoline engine, and the low load swirl generator 1 is installed between an intake port 3 formed in a cylinder head 2 and an intake manifold 4, and a sub port is provided inside. 5 is attached.

Device body 1 of swirl generator 1 under low load
Reference numeral a denotes a tubular body having flanges 1b attached to both ends thereof. The main body portion 5a of the sub-port 5 disposed in the tubular body is integrally formed with the apparatus main body 1a, and the nozzle portion 5b extending downstream is provided. A sub-port 5 is provided, and the intake inlet 5
It is formed in a cone shape having a cross-sectional area gradually reduced from c toward the intake air outlet 5d, and the intake air outlet 5d is opened so as to blow the intake air onto the fuel flow 6a injected from the injector 6. The remaining portion of the main body 5a divided by the sub port 5 is used as a main port 7, and a switching valve 8 for opening and closing the main port 7 is attached.

The sub-port 5 includes a main body 5a and a main body 1 of the apparatus.
The nozzle part 5b is formed integrally with a by precision casting or the like.
After assembling them together, they are assembled by press fitting and the cross-sectional area is
It is formed in a conical shape that gradually decreases from the intake air inlet 5c to the intake air outlet 5d. In addition, the nozzle portion 5b
Can be made of iron, aluminum, resin, etc., and can be fixed by screwing instead of press fitting.

As shown in FIG. 2, the intake port 5d of the sub-port 5 is located at a position where it is sprayed from the injector 6 attached to the intake port 3 toward the fuel jet 6a injected toward the intake port 7a of the combustion chamber 7. It was opened. Although the sub port 5 of the first embodiment is linear with respect to the axis as described above, the nozzle portion 5b may be curved depending on the shape of the intake port 3.

The main port 8 is formed as the rest of the portion occupied by the sub port 5 in the tubular portion of the apparatus body 1a.
It is formed so that it can be opened and closed by the switching valve 9 (the figure shows a state in which the main port 8 is closed). Switching valve 9
Is composed of a butterfly valve, has a link arm 9b attached to the valve shaft 9a, and is rotated by a control device (not shown).

The intake air passes through the air cleaner 10 and then flows into the low load swirl generator 1 from the intake passage 12 provided with the throttle valve 11 through the intake manifold 4, as in the case of a normal internal combustion engine. Since the switching valve 9 is open when the engine is under high load, the intake air mainly passes through the main port 8 having a small flow resistance, the fuel is mixed in the intake port 3, and the intake air is sucked into the combustion chamber 7.

Further, since the switching valve 9 is closed when the engine load is low, intake air is blown out from the sub port 5 toward the fuel jet 6a in the intake port 3 and is sucked into the combustion chamber 7.
As described above, when the engine load is low, the throttle valve 11 of the high load intake passage 12a having a large cross-sectional area is closed, and the flow passage is throttled by the throttle 11 of the low load intake passage 12b having a small cross-sectional area. It will be a small amount.

However, since the subport 5 has a small cross-sectional area and has a structure in which the area gradually decreases toward the downstream side, the flow velocity of the intake air is accelerated in the subport 5 under a smaller flow resistance, and the kinetic energy is increased. Was discharged toward the fuel jet 6a while accumulating, and a good swirl was formed in the combustion chamber 7. The combustion gas in the combustion chamber 7 is discharged from the exhaust port 3a.

As described above, the low load swirl generator 1 of the first embodiment can generate a good swirl by simply attaching the swirl generator to the intake port 3 without modifying the design of the conventional gasoline engine. Reference numeral 13a shown in FIG. 2 is an intake valve, 13b is an exhaust valve, 14 is a cylinder body,
Reference numeral 15 is a cylinder bore, 16 is a piston, and 17 is a choke valve.

FIG. 3 shows the intake outlet 5 of the sub-port 5.
The opening direction of d is shown as an example, and A of FIG.
It is cut obliquely downward so that the intake air is blown out downward, and B in FIG. 3 is cut so that the intake air is blown out obliquely upward. In addition to the above, the shape of the nozzle portion 5b can be appropriately modified and implemented according to the actual situation.

The tubular sub-port 5 of the low load swirl generator 1 according to the second embodiment shown in FIGS. 4 and 5 has an intake inlet 5c formed in a truncated circular shape and an intake outlet 5d formed in a circular shape. It was formed so as to reduce the cross-sectional area from the extended nozzle portion 5b. The switching valve 9 of the second embodiment has a valve shaft 9a.
Mounted vertically, the valve shaft 9a of each cylinder (only one is shown)
The structure is similar to that of the first embodiment except that the structure for driving the link (only the link arm 9b is shown) is simpler. The same members are denoted by the same reference numerals and the description thereof is omitted. As described above, Example 2
Although the valve shaft 9a is attached so as to penetrate the sub-port 5, the airtightness does not need to be particularly strict, because even if intake air leaks from the through hole to some extent, it does not cause a loss in quantity.

6A to 6F illustrate the shapes of the swirl generator 1 under low load on the intake inlet 5c side,
In FIG. 6A, both the subport 5 and the main port 8 have a circular cross section and are integrally formed by casting. In FIG. 6B, the flat-shaped sub-port 5 is circumscribed on the main port 8 having a circular cross-section and integrally formed by casting.

In FIG. 6C, the main port 8 having a quadrangular cross section with rounded corners is externally circumscribed with the subport 5 having a quadrangular cross section with similarly rounded corners, and is integrally formed by casting. In FIG. 6D, the main port 8 having a square cross section with rounded corners is externally attached to the sub-port 5 having a square cross section with rounded chamfered corners, and is integrally formed by casting.

In FIG. 6E, an elliptical subport 5 is disposed inside a main body 5a having a rectangular cross section with chamfered corners, and is integrally formed by casting. Formed in the remaining space. In FIG. 6F, a tubular subport 5 having a flat cross section is attached so as to be inscribed inside a main body portion 5a formed in a tube shape having a rounded rectangular cross section with rounded corners.

Since the intake port 7a of the combustion chamber 7 described above is open to the lower side of the intake port 3, the intake inlet port 5c is attached to the lower side of the main body 5a. Therefore, in FIG.
In each of ~ F, the sub port 5 is attached to the lower side of the main port 8, but this is not essential to the present invention.
It can be mounted in other locations if desired. Further, in each of the above-described embodiments, the swirl generator during low load is formed as an independent member, but the present invention is not limited to this, and it may be incorporated in the intake port or the intake manifold in advance.

[0028]

As described above, the low load swirl generator of the present invention has the following advantages. That is, it has a switching valve that closes when the load is low, and has a high-load main port with a larger cross-sectional area, an intake inlet with a smaller area, and an intake outlet with a smaller area. The configuration according to claim 1, further comprising a sub port configured to flow out near the intake port of the combustion chamber,
During high-load operation of the engine, intake air is mainly supplied through the main port with low flow resistance, so there is no risk of affecting engine performance. It is possible to form a good swirl in the combustion chamber by inflowing it into the sub-port which is the inlet, further reducing the intake outlet, accelerating the flow velocity, and letting it flow out near the intake of the combustion chamber.

The low load swirl generator is
The structure according to claim 2, wherein the structure is provided between the intake manifold and the intake port, and the outlet of the sub-port is extended into the intake port. It is possible to reduce the processing cost and the maintenance cost to a low level, and it is possible to install the existing internal combustion engine.

[Brief description of drawings]

FIG. 1 is a trihedral view of a low load swirl generator for an internal combustion engine according to a first embodiment of the present invention, where A is a front view and B is a front view.
Is a sectional view taken along line BB of A, and C is a sectional view taken along line CC of A.

FIG. 2 is a vertical cross-sectional view of a main part showing a state in which the low load swirl generator shown in FIG. 1 is incorporated in a gasoline engine.

FIG. 3A is a modification of the intake port shape of the subport, and B is another modification.

FIG. 4 is a front view of a low load swirl generator for an internal combustion engine according to a second embodiment of the present invention.

5 is an enlarged perspective view of the low load swirl generator shown in FIG. 3. FIG.

6A to 6F are views exemplifying shapes of a main port and a sub port on an intake inlet side.

[Explanation of symbols]

1 Low load swirl generator 1a Device body 2 Cylinder head 3 Intake port 4 Intake manifold 5 Sub-port 5a Body part 5b Nozzle part 5c Intake inlet port 5d Intake outlet port 6a Fuel jet 7 Combustion chamber 7a Intake port 8 Main port 9 Switching valve 9a Valve shaft 12 Intake passage

Claims (2)

[Claims] 1. A device for attaching to an intake port of an internal combustion engine for accelerating an intake flow velocity at low engine load, the main port having a larger cross-sectional area for high load and a smaller cross-sectional area for low load. And a sub-port having two intake passages, a main port is provided with a switching valve that closes when the engine is operating at low load, the intake outlet area of the sub-port is made smaller than that of the sub-port, and the intake outlet of the sub-port is formed. A low-load swirl generator for an internal combustion engine in which the engine is opened near the intake port of the combustion chamber. 2. A device which is mounted between an intake manifold and an intake port of an internal combustion engine to accelerate an intake flow velocity at low engine load, the main port having a larger cross-sectional area for high load, and a low load. Has two intake passages with a sub-port having a smaller cross-sectional area for use in the main port, and is provided with a switching valve that closes when the engine has a low load, and the intake outlet area is smaller than the intake inlet area of the sub-port, and A low-load swirl generator for an internal combustion engine in which the intake port of the sub port extends in the shape of a nozzle near the intake port of the combustion chamber.