JPH021474Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) This invention is attached to the intake passage of an engine, and creates turbulence in the air mixture flowing through it, improving the mixing properties of fuel and air. The present invention relates to a turbulence generating plate having a honeycomb structure, and particularly relates to a turbulence generating plate for an engine intake passage, which is characterized by the shape of small passages forming the honeycomb structure.

(Prior Art) In an engine equipped with a carburetor, an air flow passing through a bench lily portion of the carburetor sucks out fuel and atomizes it. However, when the engine is started at a low temperature, the temperature of the fuel is low and the viscosity of the fuel is high, so it is difficult to atomize and tends to become liquid or large droplets.
Such liquid or droplet fuel is difficult to vaporize and has poor mixability with air, making it difficult to form an air-fuel mixture with a uniform concentration.

Therefore, conventionally, as shown in US Pat. No. 3,998,195, a member having a large number of small passages is attached to the intake passage of the engine so that the air-fuel mixture passes through the small passages. proposed a system that promotes atomization and vaporization of fuel. The inventors further developed this idea by attaching a honeycomb-structured plate to the intake passage, which generates turbulent flow on the downstream side of the plate, promoting atomization of the fuel and promoting interaction with the air. It has been found that the mixability is improved.

By the way, products with this kind of honeycomb structure,
Generally, they are manufactured by combining corrugated sheets, but since such manufacturing methods require extremely complicated processes, plate-shaped objects are often cast using die-casting methods, etc. . especially,
In the case of the turbulence generating plate that is attached to the intake passage of an engine as described above, it is a relatively small-sized component, and from the standpoint of mass production, it is desirable that the plate be cast. Furthermore, since such a turbulence generating plate is not affected by the cross-sectional shape of each small passageway forming the honeycomb structure, the cross-sectional shape can be arbitrarily selected to facilitate molding of the mold. Can be done.

For this reason, it has been considered to cast the turbulence generating plate into a honeycomb structure having a large number of small passages each having a substantially square cross section and partitioned by vertical and horizontal partition walls.

(Problems to be Solved by the Invention) However, such a turbulence generating plate usually forms a circular passage as a whole in accordance with the cross-sectional shape of the intake passage. As shown in FIGS. 5A and 5B, when such a circular passage C is partitioned by vertical and horizontal partition walls r, a small passage a or a large passage b with an approximately triangular cross section is formed around the circular passage C. It will definitely be formed. Such triangular passages a and b have a cross-sectional area that is too small or too large compared to the other small passages s whose cross section is approximately square. Therefore, a large resistance is applied to the intake air flowing through the triangular passages a and b, or a sufficient turbulent flow generation effect is no longer effective.

Furthermore, when casting such a honeycomb-structured turbulence generating plate, a die casting method is generally adopted as the casting method. In that case, the cast product is removed from the mold by being pushed out with an ejector pin. Therefore, it is necessary to provide the turbulence generating plate, which is a molded product, with a pin receiving portion for receiving the ejecting pin. The area of this pin receiving portion is considerably larger than the wall thickness of the partition wall of the honeycomb structure. Therefore, the cross-sectional area of the small passage where the pin receiving part is provided is
It will be smaller than other parts. Moreover, since the pin receiving part is usually provided at the periphery of the turbulence generating plate, especially in the case as shown in FIG. I become confused.

On the other hand, when the opening degree of the throttle valve is small, such as when starting an engine, the air-fuel mixture flows along the inner surface of the intake passage. Therefore, if the intake resistance around the turbulence generating plate is large, or conversely if the cross-sectional area of the passage around the turbulence plate is too large, when it is most desired to improve the mixing properties of fuel and air, This means that the effect of the turbulence generating plate cannot be sufficiently obtained.

Moreover, the fuel adheres to the inner surface of the intake passage,
In many cases, the fuel flows down in the form of a liquid film, but in order to atomize such liquid fuel, it is necessary to make the turbulence generating plate, especially the peripheral area, work effectively.

The present invention was developed in view of these problems, and its purpose is to enable casting using a simple mold, and to allow the small passages formed in the peripheral area to overlap the small passages in other parts. The object of the present invention is to obtain a turbulence generating plate having a honeycomb structure, which has a cross-sectional area approximately equal to that of the passage, and is capable of generating sufficient turbulence even in the periphery thereof.

(Means for Solving the Problems) In order to achieve this objective, in the present invention, a circular passage surrounded by a short cylindrical peripheral wall of a turbulence generating plate is connected to a large number of vertical and horizontal bulkheads. The passageway is divided into a square passageway and four triangular passageways of relatively large area. Then, ribs are diagonally extended from the intersection of the vertical and horizontal bulkheads forming the triangular passage,
The ribs divide the triangular passage.

(Function) With this configuration, the turbulence generating plate is formed by vertical and horizontal partition walls and ribs, and a cylindrical peripheral wall, and the mold thereof has a simple shape. In addition, the triangular passages formed in the periphery are assumed to have a large cross-sectional area, and by dividing the triangular passages by diagonally extending ribs, the cross-sectional area of the small triangular passages formed by the divisions is increased. This makes it possible to make the cross-sectional area approximately equal to the cross-sectional area of the square passage in the section.

By making the ribs further extend diagonally from the intersection of the vertical and horizontal partition walls forming the triangular passage, the area of the intersection becomes larger. Therefore, the intersection point makes it possible to form a pin receiving portion for receiving an extrusion pin for die cutting after molding.

(Example) Hereinafter, an example of the present invention will be described based on the drawings.

In the drawings, FIG. 1 is a plan view showing an embodiment of the turbulence generating plate according to the present invention, FIG. 2 is a plan view and a longitudinal cross-sectional view of an insulator equipped with the turbulence generating plate, and FIG. It is a schematic side view of the intake system of the engine to which the insulator is attached. Also, the fourth
The figure is a longitudinal sectional view showing one state during the manufacturing process of the turbulence generating plate.

As is clear from FIG. 3, the combustion chamber 1a of the engine body 1 is connected from the air cleaner 2 through the carburetor 3 and intake manifold 4 to the intake port 1b.
The air-fuel mixture is supplied through an intake passage 5 leading to. The carburetor 3 is of a two-barrel type and includes a primary passage 3a that is open even when the load is low and a secondary passage 3b that is open only when the load is high. Throttle valves 3c and 3d are provided in each passage 3a and 3b, respectively.

Since the engine body 1 becomes hot during engine operation, the carburetor 3 and the intake manifold 4 are installed in order to prevent the heat from being transferred to the carburetor 3 and the fuel in the fuel passage becoming high temperature. A flat insulator 6 is provided between the two. This insulator 6 is molded from a hard resin with heat insulating properties such as Bakelite or phenol resin, and as shown in FIGS. first and second passages 6a connecting the primary passage 3a and the secondary passage 3b to the intake manifold 4, respectively;
6b is provided. A turbulence generating plate 7 is attached to one of the first passages 6a, which is connected to the primary passage 3a of the carburetor 3.

As is clear from FIG. 1, this turbulence generating plate 7
has a circumferential wall 8 having a short cylindrical shape, and this circumferential wall 8 forms a circular passage 9 having a circular cross section. In this circular passage 9, a large number of thin vertical partition walls 10 and horizontal partition walls 11 are provided at approximately equal intervals. The vertical partition wall 10 ₁ and the horizontal partition wall 11 ₁ located on the most peripheral side do not extend to the peripheral wall 8, but are stopped at the point where they intersect with the horizontal partition wall 11 ₂ and the vertical partition wall 10 ₂ on the inner side. Thus, the inside of the circular passage 9 is divided into these vertical and horizontal bulkheads 1.
A large number of square passages 12, 12, . . . with a substantially square cross section formed by
Four triangular passages 1 having a substantially right-angled isosceles triangular cross section formed by the th vertical and horizontal bulkheads 10 ₂ and 11 ₂
It is divided into 3, 13, etc. By doing so, the cross-sectional area of the triangular passage 13 becomes slightly larger than twice the cross-sectional area of the square passage 12. Therefore, a rib 15 is extended diagonally at an angle of 45 degrees from the intersection point 14 of the vertical and horizontal partition walls 10 ₂ and 11 ₂ forming this triangular passage 13.
I'm trying to divide 3 into two.

By providing the ribs 15 extending diagonally in this manner, the intersection 14 of the vertical and horizontal partition walls 10 ₂ and 11 ₂ has a large wall thickness that bulges into the triangular passage 13. Therefore, the small triangular passages 13a, 13a formed by being divided by this rib 15
has a cross-sectional area approximately equal to that of the square passageway 12.
The upper surface of this intersection 14 has a large area, thereby forming a pin receiving portion 16.

The turbulence generating plate 7 is formed by die-casting an aluminum alloy. As shown in FIG. 4, the mold 20 consists of a flat upper mold 21 and a lower mold 22 which are assembled together. The lower mold 22 is provided with a circular groove 23 for forming the peripheral wall 8 of the turbulence generating plate 7, a large number of vertical and horizontal grooves 24 for forming the vertical and horizontal partition walls 10 and 11, and grooves for forming the ribs 15. There is. These grooves 23,2
The No. 4 type has a tapered inner surface that becomes narrower toward the bottom. In addition, the lower mold 22 includes
Intersection 14 of vertical and horizontal bulkheads 10 ₂ and 11 ₂ of turbulence generating plate 7
A push-out pin 25 that can be slid up and down is provided at a position corresponding to the portion.

When casting the turbulence generating plate 7, the upper mold 21 and the lower mold 22 are assembled, and with the push-out pin 25 lowered, aluminum is poured into the space formed between the upper mold 21 and the lower mold 22. Inject molten alloy under pressure. This molten metal is guided into each groove 23, 24, etc. After cooling and hardening, the upper mold 21 is removed and the fourth
As shown in the figure, the push-out pin 25 attached to the lower mold 22 is raised. Then, this pin 25 pushes up the pin receiving portion 16 of the turbulence generating plate 7, which is a molded product. As a result, the turbulence generating plate 7 is extracted from the lower die 22. At this time,
Since each groove 23, 24 of the lower mold 22 is provided with a draft angle, the mold can be easily removed.

In this way, a turbulence generating plate 7 having a honeycomb structure as shown in FIG. 1 is obtained. This turbulence generating plate 7 is embedded and integrated inside the insulator 6 when it is molded. At this time, Fig. 2B
As shown in FIG. 2, the turbulence generating plate 7 is arranged so that the thinner side of the partition walls 10, 11, etc. is the upper surface side, that is, the upstream side. Therefore, each of the square passages 12 and the small triangular passages 13a becomes narrower toward the downstream side.

When starting the engine at a low temperature, air-fuel mixture is supplied from the primary passage 3a of the carburetor 3. This air-fuel mixture is guided to the intake manifold 4 through the turbulence generating plate 7 provided in the first passage 6a of the insulator 6. At this time, the air-fuel mixture flows through the turbulence generating plate 7
By passing through the square passage 12 or small triangular passage 13a, the air is throttled and speeded up, and is rapidly opened at the exit. Therefore, a strong turbulent flow is generated on the downstream surface of the turbulence generating plate 7, the air-fuel mixture is agitated by the turbulent flow, and the fuel becomes fine particles and is mixed with the air.

When the engine is warmed up, the opening degree of the throttle valve 3c is small. Therefore, the air-fuel mixture mainly flows around the turbulence generation plate 7, but with the above-described configuration, the air-fuel mixture flows mainly through the square passage 12 or small triangular passage 13a formed in the turbulence generation plate 7. Since the cross-sectional areas are all approximately equal, even in such a case, the intake resistance does not increase and the same effect can be obtained. Further, the liquid fuel flowing along the inner surface of the intake passage 5 can also be effectively atomized.

In addition, in the above embodiment, the triangular passage 13
, the second vertical bulkhead 10 ₂ from the periphery and the horizontal bulkhead 1
1 ₂ , but if the interval between the longitudinal and lateral partition walls 10 and 11 is smaller, the triangular passage 1 is formed by the inner longitudinal and lateral partition walls 10 and 11.
3 may be formed. In that case,
A plurality of ribs 15 are provided to further divide the triangular passage 13 into smaller pieces.

Further, such a turbulence generating plate 7 is not necessarily formed by die-casting an aluminum alloy, but may also be obtained by molding the same material as the insulator 6, for example, a resin such as Bakelite. It is clear that the same effects can be achieved in that case as well. Therefore, the term "casting" used in this specification also includes such molding of resin.

(Effect of the invention) As is clear from the above explanation, according to the invention, the honeycomb-structured turbulence generating plate is formed by a short cylindrical peripheral wall, vertical and horizontal partition walls, and ribs. , the mold for casting this can be formed with only circular grooves and linear grooves, making the molding extremely easy.

The circular passage surrounded by the peripheral wall is partitioned into a large number of approximately square cross-section passages and four relatively large-area approximately triangular cross-section passages by vertical and horizontal bulkheads, and the triangular passage is divided diagonally. Since the turbulence generating plate is divided by ribs extending in the length, the cross-sectional area of each small passage forming the honeycomb structure of the turbulence generating plate can be made to be approximately equal over the entire surface including the surrounding area. This makes it possible to prevent an increase in intake resistance when the engine runs at low speeds, and to improve the mixing properties of fuel and air.

Further, since the ribs are extended diagonally from the intersection of the vertical and horizontal partition walls forming the triangular passage, the wall thickness at the intersection becomes large. Therefore, the intersection portion can form a pin receiving portion for receiving the push-out pin for die cutting without reducing the cross-sectional area of the small passage.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing an embodiment of the turbulence generating plate according to the present invention, and FIG. 2 is a plan view showing an insulator equipped with the turbulence generating plate. - A vertical cross-sectional view taken along line B, Figure 3 is a partially cutaway schematic side view of the intake system of the engine to which the insulator is attached, and Figure 4 shows the state in which the turbulence generating plate is removed from the mold. FIG. 5 is an explanatory view for explaining the turbulence generating plate to be improved by the present invention. DESCRIPTION OF SYMBOLS 1... Engine body, 3... Carburetor, 4... Intake manifold, 5... Intake passage, 6... Insulator, 7... Turbulence generation plate, 8... Surrounding wall, 9...
Circular passageway, 10, 10 ₁ , 10 ₂ ... Vertical bulkhead, 1
1, 11 ₁ , 11 ₂ ... horizontal bulkhead, 12 ... square passage, 13 ... triangular passage, 13a ... small triangular passage, 14 ... intersection, 15 ... rib, 16 ... pin receiving part, 20 ... ...Mold, 21...Upper mold, 22...
...Lower mold, 25...Ejection pin.

Claims (1)

[Claims for Utility Model Registration] A turbulence generating plate 7 with a honeycomb structure that is attached to the intake passage 5 of an engine and generates turbulence in the air-fuel mixture passing through; surrounded by a short cylindrical peripheral wall 8. A large number of thin longitudinal and transverse bulkheads 10, 11 that partition a circular passage 9 having a substantially circular cross section into a large number of square passages 12 having a substantially square cross section and four triangular passages 13 having a relatively large area and a substantially triangular cross section; A turbulence generation plate for an engine intake passage, comprising: a rib 15 extending diagonally from the intersection 14 of the vertical partition wall 10 ₂ and the horizontal partition wall 11 ₂ forming the triangular passage 13 and dividing the triangular passage 13; .