JPS58195014A - Helical suction port - Google Patents

Abstract

PURPOSE:To provide high charging efficiency by preventing gum-like impure substance from depositing on a valve body while preventing the mixture from leaking into a branch passage at a low-speed and low-load run of an engine to aid formation of an intense swirl inside a combustion chamber and by opening and the branch passage to feed an ample flow of mixture into a helical part at a high-speed and high-load run thereof. CONSTITUTION:At a low-speed and low-load run of an engine, a rotary valve 25 is kept closed. Some of mixture sent into an inlet passage flows forward along the upper wall face 19 and 20, and a part of the rest runs against the rotary valve 25 and turns to flow along the side wall face 17. Since a part of the mixture flows against a valve body 31, if clearances between an edge 31a of the valve body 31 and a side wall face 27 and between opposite edge 31b of the valve body 31 and the second side wall face 14b are completely closed, gum-like impurities within mixture are deposited between valve body edges 31a, 31b and between the wall faces 27, 14b. For those purposes of preventing deposition of impurities and leakage from the clearance l1 and l2, annular recess 36 and 37 are formed.

Description

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

A helical intake port is usually composed of a spiral portion formed on the side of the intake valve, and an inlet passage portion that is tangentially connected to the spiral portion and extends substantially straight. When trying to generate a strong swirling flow in the engine combustion chamber using such a helical type intake (je-) when the engine is operating at low speed and low load with little intake air I, the shape of the intake air intake becomes a shape with large flow resistance. This causes a problem in that the charging efficiency decreases when the engine is operated at high speed and under high load with a large amount of intake air. To solve this problem, a branch path is formed in the cylinder head that branches from the helical intake port entrance passage and communicates with the spiral end of the helical intake port spiral section. The applicant has already proposed a helical intake port in which an on-off valve is provided at the engine speed and the on-off valve is opened during high-speed, high-load operation of the engine. In this helical type intake port, when the engine is operated at high speed and under high load, a part of the intake air sent into the helical type intake port inlet passage is sent into the helical type intake port spiral part through a branch path, so the intake air flow path is The cross-sectional area increases,
In this way, filling efficiency can be improved. 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 an initial shape, and if a branch passage that is completely independent from the inlet passage is added, the overall structure of the intake port will be extremely crude, so Helical intake port with branching path to cylinder,
It is quite difficult to form inside the body.

SUMMARY OF THE INVENTION The object of the present invention is to provide a helical intake port that can obtain high filling efficiency when the engine is running at high speed and high load, and has a new shape that is easy to manufacture.

Please refer to the attached drawings below.1. The present invention will now be described in detail.

Referring to FIG. 1 and FIG. 2, 1 is a cylinder block, a piston that moves back and forth within the two-piece cylinder block 1,
3 is the cylinder pro, the cylinder head fixed on Ri 1, the combustion chamber formed between the 4Fi piston 2 and the cylinder, and the cylinder 3, 5 is the intake valve, and 6 is the helical formed in the cylinder head 3. 7 is an exhaust valve, 8 is an exhaust port formed in the cylinder head 3, 9 is an ignition plug disposed in the combustion chamber 4, and a stem guide for guiding the stem 5a of the intake valve 5 is shown. show. As shown in FIGS. 1 and 2, on the soil wall surface 11 of the intake port 6, there are
A partition wall 12 with a projecting door is integrally molded, and this partition wall 12'vc
Therefore, a helical intake valve is formed, which includes a spiral portion B and an inlet passage portion A that is tangentially connected to the spiral portion B. This partition wall 12
extends from inside the inlet passage A to around the stem guide 10 of the intake valve 5, and as can be seen from FIG.
The width of the base of 2 is from the entrance passage A to the stem guide 1o.
It gradually becomes wider as it approaches. The partition wall 12 is an inlet opening of the intake port 6.

In FIG. 2, the partition wall 2 has a first side wall surface 141 extending counterclockwise from the tip 13 to the stem guide 1o, and a partition wall 141 extending counterclockwise from the tip 13 to the stem guide 1o; The stem 2 side wall surface 14b extends around the stem guide 10. The first side wall surface 1411 extends from the distal end portion 13 through the side of the stem guide 10 to the vicinity of the side wall surface 15 of the spiral portion B, and forms a narrow portion 16 between the first side wall surface 1411 and the spiral portion side wall surface 15 . Next, the 11111th wall surface 14a
The spiral portion @ extends to the stem guide 10 while being curved so as to be gradually spaced apart from the wall surface 15. On the other hand, in the second@wall surface 14b, the stem extends almost straight from the tip 13 to the id 10.

Referring to FIGS. 1 to 9, the side wall surfaces 17, 18 of the inlet passage section A are arranged substantially vertically, and the earth wall surface 19 of the inlet passage section A gradually descends toward the spiral section BK. The side wall surface 17 of the entrance passage section A is smoothly connected to the side wall surface 15 of the spiral section B, and the earth wall surface 19 of the entrance passage section A is smoothly connected to the earth wall surface 2o of the spiral section B. The earthen 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 as it passes through the narrowed portion 16. On the other hand, as shown in FIG. 5, the bottom wall surface 21 of the inlet passage section 6 is almost horizontal in its entirety in the vicinity of the inlet opening 6a, and the bottom wall surface 21m adjacent to the side wall surface 17 is as shown in FIG. As shown, the spiral part BK
As you get closer, it rises and forms an inclined surface. The angle of inclination of this inclined bottom wall surface portion 211 gradually increases as it approaches the spiral portion B.

On the other hand, the first side wall surface 14m of the partition wall 12 is a slightly downwardly inclined surface, and the second side wall surface 14b is substantially vertical. The bottom wall surface 22' of the partition wall 12 is slightly curved from the entrance passage section A toward the spiral section B so that the distance between the entrance passage section 6 and the soil wall surface 11 gradually increases from the tip end 13 toward the stem guide 10. Go down.

On the bottom wall surface 22 of the partition wall 12, there are marks shown by C and Chinda in FIG.
.

A lip 23 protruding downward from the bottom wall surface 22 is formed in the area where the bottom wall surface 22 is located, and the bottom surface of this I)f23 and the bottom wall surface 22 form a slightly curved slope.

On the other hand, the spiral end C of the spiral portion B is inserted into the cylinder and inside the door 3.
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 a distance IP12, and the entire lower space of the branch passage 24 is connected to the inlet passage part Am. The upper wall surface 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. The side wall surface 27 of the branch passage 24 facing the second side wall surface 14b of the partition wall 12 is substantially perpendicular, and furthermore, this ll1l wall surface 27 is located approximately at an extension of the *Il wall surface 18 of the inlet passage section A. In addition,
As can be seen in FIG. 1, the ribs 2.1:':ni'.:ha.--11: of the tarry valve 25 are formed on the K11M wall 12.

It extends from the vicinity 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 and K rotatably supported within the rotary valve holder 28. It is screwed into a screw hole 30 drilled in 3.

A thin plate-shaped valve body 31 is integrally formed at the lower end of the valve shaft 29, and as shown in FIG. On the other hand, the valve stem 29
An arm 32 is fixed to the upper end of. In addition, the valve shaft 29
A ring groove 33 is formed on the outer peripheral surface of the ring groove 33, and an E-shaped positioning ring 34 is fitted into the ring groove 33. Further, a seal member 35 is fitted to the upper end of the rotary valve holder 28, and the seal member 35 performs a sealing action on the valve shaft 29. On the other hand, as shown in FIGS. 2 and 4, a partially cylindrical groove 36 is formed on the branch road side wall surface 27 facing one edge 311 of the valve body 31. and the rotor as shown in Fig. 4 *25
is in the closed position.

The edge 31a of the valve body 31 enters into the groove 36 at a distance t1 from the wall surface of the groove 36. On the other hand, a partially cylindrical groove 37 is also formed on the second side wall surface 14b of the partition wall 12 facing the other edge 31b of the valve body 31, and as shown in FIGS. 2 and 4, the rotary valve 25 is in the closed position, the edge 31b of the valve body 31 enters the groove 37 at a distance t2 from the wall surface of the groove 37. Note that the center of the cylinder forming these grooves 36 and 37 coincides with the rotation axis of the valve body 31. Referring to FIG. 11, the tip of the arm 32 fixed to the upper end of the rotary valve 25 has a negative pressure diaphragm f40
A control port fixed to a diaphragm 41 is connected to a door 42 via a connecting rod 43. The negative pressure diaphragm device 40 has a negative pressure chamber 44 isolated from the atmosphere by a diaphragm 41, and a compression spring 45 for pressing the diaphragm is inserted into the negative pressure chamber 44. To the cylinder, 1 to C3
An intake manifold 47 equipped with a connoun type carburetor 46 consisting of a next side carburetor 46m and a secondary side carburetor 46b is attached, and the negative pressure chamber 44 is connected to the inside of the air manifold 47 via a negative pressure conduit 48. . A check valve 49 is inserted into the negative pressure conduit 48 and allows flow only from the negative pressure chamber 44 into the intake manifold 47 . Furthermore, the negative pressure chamber 44 is connected to the atmosphere via the atmosphere conduit 5o and the atmosphere release control valve 51.

This serious release control valve 51 has a negative pressure chamber 53 and an atmospheric pressure chamber 54 separated by a diaphragm 52, and further has a valve chamber 55 adjacent to the atmospheric pressure chamber 54. This valve chamber 55 is connected to the negative pressure chamber 44 via the atmospheric conduit 5o on the one hand,
On the other hand, the valve port 56 as well as the air filter 57 communicate with the atmosphere.

A valve body 58 is provided for controlling the opening and closing of the KII'i center port 56 within the valve chamber 55, and is connected to the diaphragm 52 via a valve port and a door 59. A compression spring 6o for pressing the diaphragm is inserted into the negative pressure chamber 53, and the negative pressure chamber 53 is connected to the pliers 62 of the primary side carburetor 46a via a negative pressure conduit 61.

The carburetor 46 is a commonly used carburetor, and when the primary throttle valve 63 opens a predetermined opening or more, the secondary throttle valve 64 opens, and when the primary throttle valve 63 fully opens, it opens 2 times. The next slot and torque valve 64 are 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, so the negative pressure generated in the pliers and υ section 621C becomes larger than the predetermined negative pressure. When the engine is operated at high speed and high load, the diaphragm 52 of the atmospheric release control valve 51 moves to the right against the compression spring 60 [7, and as a result, the valve body 58 opens the valve port 56. The negative pressure chamber 44 of the negative pressure diaphragm device 40 is opened to the atmosphere. At this time, the diaphragm 41 is moved in one direction by the biasing force of the compression spring 45, and as a result, the rotary valve 25 is rotated to completely unify the branch passage 24.

On the other hand, when the opening degree of the primary side slot and torque valve 63 is small, the negative pressure generated in the bench and υ part 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 +1 60. However, the valve body 58 is a valve.

Close port 56. 9. Furthermore, in this way, the primary side
゛...(When the opening degree of the Loitre valve 63 is small, a large negative pressure is generated inside the intake manifold 4.The check valve 49 has a negative pressure diaphragm device [40
When the negative pressure in the negative pressure chamber 44 also increases, the valve opens and suction>
1. When the negative pressure in the manifold 47 becomes smaller than the negative pressure in the negative pressure chamber 44, the valve closes, so as long as the atmospheric release control valve 51 is closed, the negative pressure in the negative pressure chamber 44 flows into the intake manifold 47. The maximum negative pressure generated is maintained. When a negative pressure is applied to the negative pressure chamber 44, the die phragm 41 is upwardly moved against the compression spring 45, and as a result, the rotary valve 25 is rotated and the branch passage 24 is closed. Therefore, when the engine is running at low speed and with a low load, the branch passage 24 is closed by the rotary valve 25. Even during high load operation, if the engine speed is low, and when the engine I]J rotation speed is Even if the pressure is high, the atmospheric release B1 valve 51 remains closed when low-load operation is being performed because the negative pressure generated in the venturi section 62 is small. During load operation, the branch passage 24 is closed by the rotary valve 25 because the negative pressure in the negative pressure chamber 44 is maintained at the maximum negative pressure '1' mentioned above.

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, a part of the air-fuel mixture sent into the inlet passage part A tilts toward the earth wall surface 19.20, and part of the remaining air-fuel mixture collides with the rotary valve 25. Population passage section A
He turned toward the full wall surface 17 and proceeded along the side wall surface 15 of the spiral portion B. As mentioned above, the shed surface 19.
The width of 20 gradually narrows as it approaches the narrowed part 16, so the flow path for the mixture flowing along the earth wall surfaces 19 and 20 gradually narrows, and thus the air mixture flow along the earth wall surfaces 19 and 20 gradually increases. be speeded up. Furthermore, as mentioned above, the partition wall 1
Since the first side wall surface 14a of No. 2 extends to the vicinity of the side wall surface 150AI of the vortex section B, the mixed air flow active on the first wall surface 19.20 is pushed onto the side wall surface 15 of the vortex section B, and then A strong swirling flow exists in the spiral portion B because it flows along the wall surface 15.

is caused to occur. The mixture then swirls and flows into the combustion chamber 4 through the gap formed between the intake valve 5 and its valve seat. This generates a strong swirling flow within the combustion chamber 4. In this way, when the engine is operated at low speed and under low load, a part of the air-fuel mixture collides with the valve body 31, so that the edges 31 and 11 of the valve body 31 are
between the in wall surface 27 and the edge 31b of the valve body 31 @
When the space between the two side wall surfaces 14b is completely closed, impurities such as gum contained in the air-fuel mixture will be removed from the valve body edge 31m+31.
b and the side wall surface 27.14b, as a result of which the valve body 31
This results in a gap in which the material becomes stuck to the side wall surface 27.14b. Therefore, in order to avoid such problems, in the present invention, between the valve body edge 31m and the side wall surface 27, and between the valve body edge 31
A gap is provided between the second side wall surface 14b and the second side wall surface 14b to prevent impurities such as gum from accumulating. However, if such gaps are simply provided, the amount of air-fuel mixture leaking through these gaps will increase, and the swirling flow generated in the swirl portion B will be weakened. In particular, the valve body edge 31
The air-fuel mixture leaking from between 1 and the side wall surface 27 travels along the side wall surface 27 and collides head-on with the swirling flow of the swirl portion B, extremely weakening the swirling flow. Therefore, in the present invention, as shown in FIGS. 2 and 4, grooves 3 are formed in the side wall surfaces 27 and 14b, respectively.
6.37 was formed.

Within these grooves 36 and 37, the valve body edge 311°3
A gap N1tll-2 is formed between 1b and 1b to reduce leakage of the air-fuel mixture. ``Karae''chi, 12th
As shown in Figure (a), when a space r'JL1+lt is formed between the flat side wall surfaces 27, 14b and the valve body edges 31m, 31b, the air-fuel mixture passes through H'1 st2 between them. Therefore, the amount of 5t1t of the air-fuel mixture increases. On the other hand, as shown in FIG. 12(b), each side wall surface 27.
Recessed grooves 36.37 are formed on each of the recessed grooves 36.37, and a 12th
Between the same dimensions as the figure (&) @l 1 e'! In the case where the air-fuel mixture flow path is bent as shown by the arrow, the flow resistance to the air-mixture flow increases, and thus the amount of leakage of the mixture is reduced. FIG. 13 shows the relationship between these jl + cutting t・, t・ and the strength 1′ of the swirling flow. In Fig. 13, the horizontal axis shows the number of turns of the whirlpool flow per rotation time, and the horizontal axis shows the number of turns of the whirlpool flow per rotation time.
Showing snow.

In addition, in Fig. 13, the solid lines are shown in Fig. 2 and Fig. 12 (
As shown in b), grooves 36 are formed on the side wall surfaces 27 and 14b, respectively.
．． 37 is formed, and the broken line shows the case where grooves 36 and 37 are not formed as shown in FIG. 12(a). From Fig. 13, if the grooves 36 and 37 are not formed, the gap 1
It can be seen that when increasing 1.1g, the number of turns S of the swirling flow decreases accordingly. On the other hand, when the groove 36 is formed, the gap 1. ．． It can be seen that the swirling rotation ps of the first flow of the swirling medium does not decrease significantly even when the amount of the swirling medium is increased by 1 g. In addition, from FIG. 13, these gaps t1. t@
It can be seen that it is desirable to reduce the power to 0.6 W or less.

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 streams. That is,
The first flow flows between the first side wall surface 14m of the partition wall 12 and the side wall surface 17 of the inlet passage section A (1:1), and then flows into the upper wall surface 20 of the JF section A. t=i is a hot air flow that flows while swirling, 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 hot air flow that flows through the bottom wall surface of the inlet passage part A. 21 along spiral part B
This is the mixed airflow flowing into the air.

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. In this way, the mixed air flow in the branch passages 24 with low flow resistance is increased, and the flow direction of the first mixed air flow is further deflected downward, so that a high filling efficiency can be obtained. Also, as mentioned, there is a gap! ! Since the bottom wall surface of 21 is formed from a downwardly inclined surface, the third air mixture flow is guided by this inclined surface and the flow direction is deflected downward, thus achieving even higher filling efficiency.

Further, in the helical type intake port according to the present invention, the partition 1112 can be integrally formed on the earthen wall surface 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 operated at low speed and under low load, it is possible to prevent impurities such as gum from accumulating on the valve body and to prevent the air-fuel mixture from leaking into the branch passage. It is possible to generate a swirling flow. on the other hand,
When the engine is operating at high speed and high load, by opening the branch passage, a large amount of air-fuel mixture flows through the branch passage with low resistance and is sent into the volute, resulting in high filling efficiency.

[Brief explanation of drawings]

Figure 1 is like Figure 2! 2 is a side sectional view of the internal combustion engine according to the present invention taken along line 1-1 of FIG. 1.
3 is a side view schematically showing the shape of the helical intake port according to the present invention; FIG. 4 is a plan view schematically showing the shape of the helical intake port;
Figure 5 is a sectional view taken along the line ■-■ in Figures 3 and 4, Figure 6 is a sectional view taken along the line Vl--Vl in Figures 3 and 4, and Figure 7. ■- in Figures 3 and 4
Figure 8 is a cross-sectional view taken along line ■--■ in Figures 3 and 4, Figure 9 is a cross-sectional view taken along line 114 in Figures 3 and 4. Fig. 10 is a side sectional view of the rotary valve, Fig. 11 is a diagram showing the drive control device of the rotary valve, and Fig. 12 explains the flow of air-fuel mixture in the gap formed at the edge of the valve body. Figure 13 is a graph showing the strength of the swirling flow. 4... Combustion chamber, 6... Helical intake/-), 12
...Partition wall, 24... Branch passage, 25... Rotary valve, 31... Valve body, 36.37... Concave groove. Patent Applicant Toyota Motor Corporation Patent Attorney Akira Aoki Patent Attorney Kazuyuki Sunatate Patent Attorney Kyosuke Nakaichi a) (b) Figure 13

Claims (1)

[Claims] In a helical intake port configured with a spiral portion formed on the intake valve side and an inlet passage portion connected tangentially to the spiral portion and extending approximately straight, the intake port branches from the inlet passage portion. A branch passage communicating with the spiral terminal end of the spiral part is provided in the inlet communication passage part, and the core branch passage is connected to the entrance by a partition wall that projects downward from the upper wall surface of the intake port and extends from the inlet passage part to around the intake valve stem. It is separated from the passage part, and the entire lower space of the branch passage communicates with the entrance passage part in the cross section, and the passage walls of the nucleus entrance passage part and the branch passage are integrally connected, and the inside of the branch passage is A rotary valve body is provided in the valve body to control the intake air flow flowing through the branch passage, and a partially cylindrical valve is provided on the inner wall surface of the branch passage facing the valve body edge parallel to the rotation axis of the valve body. A helical intake port that forms a groove so that the edge of the valve body can enter into the groove.