JPS58200030A - Helical suction port - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] The present invention relates to a helical m-intake port.

A helical intake port usually consists of a spiral formed in the intake valve leg and an inlet passageway tangentially connected to the spiral and extending substantially straight. If you try to use such a helical intake port to generate a strong swirling flow in the combustion chamber of the engine when the engine is operating at low speed and low load with a small amount of intake air, the shape of the intake port will have a large flow resistance. A problem arises in that the filling efficiency decreases when the engine is operated at high speed and under high load with a large amount of air. In order to solve this problem, a branch path is formed in the cylinder head that branches from the helical intake/-) inlet passage and communicates with the spiral end of the helical intake port spiral section, and a branch path that opens and closes within the branch path. The applicant has already proposed a helical intake 4-way valve that is provided with a valve to open the on-off valve during high-speed, high-load engine operation. With this helical-type intake port, during high-speed, high-load operation of the Hiro engine, part of the intake air sent into the helical-type intake port inlet passage is sent into the helical-type intake port volute via the branch passage, so the intake air flow is reduced. The cross-sectional area of the path can be increased, thus improving the filling efficiency.

However, in this helical intake port, the branch passage is formed as a cylindrical passage completely independent from the inlet passage, so the flow resistance of the branch passage is relatively large, and the branch passage is formed adjacent to the inlet passage. This limits the cross-sectional area of the inlet passage, making it difficult to obtain a sufficiently high filling efficiency. Furthermore, the helical intake port itself has a complicated shape, and if a branch passage that is completely independent from the inlet passage is provided, the overall structure of the intake port will be extremely complicated. It is difficult to form a helical intake port with a helical type in the cylinder head.

SUMMARY OF THE INVENTION The present invention provides a helical intake port that is capable of achieving high filling efficiency during high-load operation of an engine and has a new shape that is easy to manufacture.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

Referring to FIG. 1 and FIG. 2, 1 is a cylinder block, 2 is a piston that reciprocates within the cylinder block 1,
3 is a cylinder head fixed on the cylinder block 1; 4 is a combustion chamber formed between the piston 2 and the cylinder head 3; 5 is an intake valve; 6 is a helical intake port formed within the cylinder head 3. , 7 is an exhaust valve, 8 is an exhaust port formed in the cylinder head 3, 9 is a spark plug disposed in the combustion chamber m4, and 10 is a stem guide for guiding the stem 5at of the intake valve 5. As shown in Fig. 1 and Fig. 2, a partition 1i12 projecting downward is integrally molded on the lower wall surface 11 of the intake port 6, and this partition 12 connects the spiral portion B to the spiral portion BK in a tangential manner. A helical intake port 6 consisting of nine artificial passages A is formed. This partition wall 12 extends from inside the inlet passage section A to around the stem guide 10 of the intake valve 5.As can be seen from FIG. It gradually becomes wider as it approaches. The bulkhead 12 has a tip 1iB13 located on the side closest to the inlet opening 6a of the intake boat 60, and the bulkhead 12 further extends counterclockwise from this tip 13 to the stem guide 10 in FIG.
1, and a second side wall surface 14b extending clockwise from the distal end portion 13 to the stem guide 10. 1st flA'm1li] 14 m is the tip 1
3 to the vicinity of the side wall surface 15 of the spiral portion B through the side of the stem guide 10 to form a narrow portion 16 between the spiral portion B and the side wall surface 15 of the spiral portion B. Next, the curved stem of the first side wall surface 14m is gradually spaced apart from the spiral portion side wall surface 15 and extends to the id 1o. On the other hand, the second side wall surface 14b extends substantially straight from the distal end portion 13 to the stem guide 10. A partially cylindrical groove 14c is formed on the second side wall 14b around the axis of the intake valve stem 5a, and this groove *
The lower end of the stem guide 1o is fitted into the upper end of l4e. Stem guide 10Fi has a cylindrical shape,
Therefore, as shown in FIG.
The side walls 11i14b protrude into the spiral portion B.

Referring to FIGS. 1 to 9, the side wall surfaces 17,18 of the inlet passage section A are substantially vertically arranged, while the upper wall surface 19 of the inlet passage section A gradually descends towards the vortex i section B. The side wall surface 17 of the inlet passage sh is smoothly connected to the side wall surface 15 of the spiral part B, and the upper wall surface 19 of the inlet passage part A is smoothly connected to the upper wall surface 2o of the spiral part B. The upper wall surface 2o of the spiral portion B gradually narrows in width while descending from the connecting portion between the spiral portion B and the inlet passage portion A toward the narrowed portion 16, and then gradually widens after passing through the narrowed portion 16. On the other hand, the lower wall surface 2 of the inlet passage section 6
1Fi As shown in FIG. 5, the entire area near the inlet opening 6a is almost horizontal, and the bottom wall surface portion 21m adjacent to the side wall surface 17 is curved as it approaches the spiral portion B as shown in FIG. It rises to form an inclined surface. The angle of inclination of this inclined bottom wall surface portion 21m gradually increases as it approaches the spiral portion B.

On the other hand, the first side wall surface 14 of the partition wall 12 has a slightly inclined downward slope, and the 211141st surface 14b
is almost vertical. The bottom wall surface 22 of the partition wall 12 has a tip end 13
It descends from the inlet passage A toward the spiral part 1 while slightly curving so that the distance from the upper wall surface 11 of the inlet passage A gradually increases as it moves toward the Sudem guide 10. A lip 23 is formed on the bottom wall surface 22 of the partition wall 12 in the region indicated by hatching in FIG. 4, and projects downward from the bottom wall surface 22. form a surface.

On the other hand, inside the cylinder head 3, there is an end portion C of one turn of the spiral portion B.
A branch passage 24 is formed which communicates the inlet passage A with the inlet passage A, and a rotary valve 25 is disposed at the entrance of the branch passage 24.

This branch passage 24 is separated from the inlet passage part A by the partition wall 12, and the entire lower space of the branch passage 24 communicates with the inlet passage part A. The upper wall surface 9:26 of the branch passage 24 has a substantially uniform width, gradually descends toward the spiral terminal end C, and is smoothly connected to the upper wall surface 20 of the spiral section B. Bulkhead 1
Side wall surface 2 of branch path 24 facing second side wall surface 14b of No. 2
7 is approximately vertical, and furthermore, this 1IllWk direction 27 is located approximately on an extension of the side wall surface 18 of the entrance passage. As can be seen from FIG. 1, the pipe 23 formed on the partition wall 12 extends from the vicinity of the rotary valve 25 toward the intake valve 5.

As shown in FIG. 10, the rotary valve 25 is composed of a rotary valve holder 28 and a valve shaft 29 rotatably supported within the rotary valve holder 28. The screw hole 30 is screwed into the screw hole 30.

A thin plate-shaped valve body 31 is integrally formed at the lower end of the valve shaft 29, and as shown in FIG. 1, this valve body 31 extends from the soil wall surface 26 of the branch passage 24 to the bottom wall surface 21f. On the other hand, valve stem 2
An arm 32 is fixed to the upper end of 9. Finally, a ring #133 is formed on the outer peripheral surface of the valve shaft 29, and an E-shaped positioning ring 34 is fitted into the puffer groove 33. Further, a sealing member 35 is fitted to the upper end of the rotary valve holder 28, and this sealing member 35 allows the valve shaft 29 to be
□1 sealing action is performed.

Referring to FIG. 11, the tip of the arm 32 fixed to the upper end of the rotary valve 25 is connected to a negative pressure diaphragm device 40.
It is connected via a connecting rod 43 to a control rod 42 fixed to a diaphragm 41 of. Negative pressure diaphragm device 4041 has a negative pressure chamber 44'Jk isolated from the atmosphere by the diaphragm 41, and a compression spring 45 for pressing the diaphragm is inserted into this negative pressure chamber 44. cylinder head 3
The intake manifold 47 is equipped with a compound type carburetor 46 consisting of a primary side carburetor 46m and a secondary side carburetor 46b.
is dammed, and the negative pressure '1A44 is connected into the intake manifold 47 via the negative pressure conduit 48. This negative pressure conduit 48
A check valve 49 that allows flow only from the negative pressure chamber 44 into the intake manifold 47 is inserted therein. Furthermore, negative pressure chamber 4
4 communicates with the atmosphere via an atmosphere conduit $50 and an atmosphere release control valve 51.

The atmospheric release control valve 51 has a negative pressure chamber 53 and an atmospheric pressure valve 54 separated by a diaphragm 52, and further has a valve chamber 55 adjacent to the atmospheric pressure chamber 54. This valve chamber 55 communicates with the negative pressure chamber 44 via an atmospheric conduit 50 on the one hand;
On the other hand, it communicates with the atmosphere via a valve (/-) 56 and an air filter 57.

Inside the valve 'M55 is a valve body 5 that controls the opening and closing of the valve port 56.
A valve body 58 is connected to the diaphragm 52 via a valve rod 59. A pressure spring 60 for pressing the diaphragm is inserted into the negative pressure chamber 53, and the pressure spring 60 is inserted into the negative pressure chamber 53.
is the bench of the primary side vaporizer 46m via the negative pressure conduit 61,
62.

The carburetor 46 is a normally used carburetor, and when the first throttle valve 63 opens a predetermined opening degree or more, the second throttle valve 64 opens, and if the primary throttle valve 63 fully opens, the second throttle valve 64 opens. The far side throttle valve 64 is also fully opened. The negative pressure generated in the venturi section 62 of the primary side carburetor 461 increases as the amount of intake air supplied into the engine cylinder increases. In other words, when the engine is operating at high speed and high load, b
tw, the diaphragm 52 of the atmospheric release control valve 51 moves to the right against the compression spring 60, and as a result, the valve body 58 opens the valve port 56, opening the negative pressure chamber 44 of the negative pressure diaphragm device 40 to the atmosphere. open to At this time, the diaphragm 41 is moved downward by the spring force of the compression spring 45, and as a result, the rotary valve 25 is rotated and the branch passage 24 is fully opened.

On the other hand, when the opening degree of the primary throttle valve 63 is small, the negative pressure generated in the venturi section 62 is small, so the diaphragm 52 of the atmospheric release control valve 51 moves to the left by the spring force of the compression spring 60, and the valve body 58 closes valve port 56. Furthermore, when the opening degree of the primary throttle valve 63 is small as described above, a large negative pressure is generated within the intake manifold y47. The check valve 49 opens when the negative pressure in the intake manifold 47 becomes larger than the negative pressure in the negative pressure chamber 44 of the negative pressure diaphragm device 40, and the negative pressure in the intake manifold 47 becomes larger than the negative pressure in the negative pressure chamber 44. The valve closes when the pressure becomes smaller than the pressure, so as long as the atmospheric release control valve 51 is closed, the pressure inside the load chamber 4 is maintained. Scallop intake: “”q=$k )−4□4 is maintained at the maximum negative pressure generated. When negative pressure is applied to the negative pressure chamber 44, the diaphragm 41 rises against the compression spring 45, and as a result, the rotary valve 25 rotates.
Therefore, the branch road 24 is closed. In addition, if the engine speed is low even if the engine speed is turned on during high load operation, or if the engine speed is high but low load operation is being performed, the bench, ! Since the negative pressure generated in the JW 62 is small, the atmospheric release shutoff valve 51 continues to be closed. Therefore, during such low-speed, high-load operation and high-speed, low-load operation, the negative pressure in the negative pressure chamber 44 is maintained at the aforementioned maximum negative pressure, so the branch passage 24 is closed by the rotary valve 25.

As described above, the rotary valve 25 closes the branch passage 24 when the engine is operated at low speed and under low load with a small amount of intake air. At this time, part of the air-fuel mixture sent into the inlet passage section A advances along the upper wall surface 19,20, and part of the remaining air-fuel mixture collides with the rotary valve 25 and passes through the inlet passage. Part A
1Il of the spiral part B after changing the direction toward the side wall surface 17 of
i Proceed along the wall surface 15. As mentioned above, the upper wall surface 19.
The width of 20 gradually narrows as it approaches the narrowed part 16, so the flow path of the mixture flowing along the soil wall surface 19.20 gradually narrows, and thus the speed of the mixture flow along the upper wall surface 19.20 gradually increases. be done. Furthermore, as mentioned above, the partition wall 1
2, the first IIIllI1 surface 14m is the side wall surface 15 of the spiral portion B.
Since the mixture flow extends close to the upper wall surface 19,20, it is pushed onto the side wall surface 15 of the swirl section B, and then proceeds along the me surface 15, so there is a strong swirl inside the swirl section B. A flow is generated. Next, the air-fuel mixture swirls and flows into the combustion chamber 4 through the gap formed between the intake valve 5 and its valve seat, generating a strong swirling flow within the combustion chamber 4.

On the other hand, when the engine is operated at high speed and under high load with a large amount of intake air, the rotary valve 25 is opened, so that the air-fuel mixture sent into the inlet passage A is roughly divided into three flows. That is,
The first flow flows between the first side wall surface 14m of the partition [12] and the side wall surface 17 of the inlet passage section A, and then flows into the upper surface 2 of the spiral section B.
0), the second flow is a mixed air flow that flows into the swirl part B via the branch passage 24, and the third flow is a mixed air flow that flows into the swirl part B through the branch passage 24, and the third flow is a mixed air flow that flows along the bottom wall surface 21 of the inlet passage part A. This is a mixed air flow that flows into the swirl portion B along the .

The flow resistance of the branch path 24 is between the first side wall surface 14m and the side wall surface 17.
Therefore, the second mixed air flow is larger than the first mixed air flow.

Furthermore, the flow direction of the first air mixture flowing while swirling in the swirl portion B is deflected downward by the second air mixture, thus weakening the swirling force of the first air mixture. Furthermore, as described above, since the stem guide 10 protrudes into the spiral portion B, flow resistance increases near the soil wall surface 20 of the spiral portion B, and as a result, flow into the spiral portion B from the branch path 24 occurs. The second air mixture flow is deflected downward so that the first
The air mixture is deflected further downward. In this way, the mixed air flow from the branch passage 24 with low flow resistance increases, and the W
, 1. Since the flow direction of the mixed air flow is deflected downward, high filling efficiency can be obtained. Further, as mentioned above, since the bottom wall surface of the partition wall 21 is formed as a downwardly inclined surface, the third air mixture flow is guided by this inclined surface and the flow direction is deflected downward, thus further increasing the filling rate. Efficiency will be gained.

On the other hand, as described above, since the stem guide 10 protrudes into the spiral part B, the stem guide 10 is connected to the air mixture swirling inside the winding part B and the air mixture flowing into the spiral part B from the branch m24. be exposed to Therefore, stem guide 1
0 is cooled by the air mixture flow so that the intake valve stem 5
It is possible to prevent the seizure of &, and also to promote the vaporization of the fuel in the air-fuel mixture.

Further, in the helical type intake port according to the present invention, the partition wall 12 can be integrally formed on the upper circle of the intake port 6, so that the helical type intake port can be easily manufactured.

As described above, according to the present invention, when the engine is operating at low speed and low load, the branch passage is disconnected and a large amount of air-fuel mixture is delivered to the upper mtI of the Gimaki section.
By flowing Dfca, a strong swirling flow can be generated inside the combustion chamber. On the other hand, during engine high-speed, high-load operation, a large amount of air-fuel mixture flows by opening the branch passage, and is sent into the volute through the branch passage with low resistance, and the mixture flow is further deflected downward by the stem guide. High filling efficiency can be obtained.

[Brief explanation of the drawing]

1 is a side sectional view of an internal combustion engine according to the present invention taken along line 1-1 in FIG. 2, FIG. 2 is a sectional plan view taken along line 1--1 in FIG. 11 is a plan view schematically showing the shape of the helical air intake 4-t according to the present invention, FIG. 4 is a plan view schematically showing the shape of the helical air intake, and FIG. Cross-sectional view taken along the ■-v line in Figure 4,
Fig. 6 is a sectional view taken along the Vt-Vt line in Figs. 3 and 4, Fig. 7 is a sectional view taken along the ■-■ line in Figs. 3 and 4, and Fig. 8 is a sectional view taken along the ■-■ in Figures 3 and 4
Figure 9 is a cross-sectional view taken along the -X line in Figures 3 and 4, Figure 10 is a side cross-sectional view of the rotary valve, and Figure 11 is the drive of the rotary valve. It is a figure showing a control device. 4... Combustion chamber, 6... Helical intake 4-to, 10
... Stem guide, 12... Bulkhead, 24... Branch passage, 25... Rotary valve. Figure 2 Figure 4 Figure 5 Figure 7! a 91!1 Wp18 Figure 10

Claims (1)

[Claims] In a helical intake port configured with a spiral part formed around the intake valve and an inlet passage part connected tangentially to the spiral part and extending almost straight, the intake port is branched from the inlet passage part. A branch passage communicating with the spiral terminal end of the upper winding part is provided in the above-mentioned inlet passage part, and the branch passage is connected by a partition wall that protrudes downward from the earth wall surface and extends from the inlet passage part to around the intake valve stem. It is separated from the inlet passage, the entire lower space of the branch passage communicates with the inlet passage in a cross section, and the passage walls of the inlet passage and the branch passage are integrally connected, and the branch passage is separated from the inlet passage. A helical-type intake port is provided with an on-off valve therein, the on-off valve controls the flow of intake air flowing through the branch passage, and a part of a stem guide supporting the intake valve is disposed within the spiral portion.