JPS58200026A - Helical suction port - Google Patents

Abstract

PURPOSE:To prevent an accumulation of impurities such as gum material and leakage of air-fuel mixture from occurring and to expedite vaporization of liquid fuel accumulated in a groove, by a method wherein the groove is formed on a wall surface of the bottom of a suction port and a cooling water duct is provided in the vicinity of the groove. CONSTITUTION:When a space between the lower end of a valve plug 31 and a bottom wall surface 21 is blocked completely the valve plug 31 is sticked on the wall surface 21 of the bottom of a titled port by accumulating impurities, such as a gaseous material to be contained in air-fuel mixture on a lower end part of the valve plug 31 as air-fuel mixture collides against the valve plug 31 at the time of a low speed load operation of an engine. To prevent an above-stated matter from occurring a hollowed groove 36 is formed on the wall surface 21 of the bottom of the titled port and a labyrinth seal is formed by the tip part of the valve plug 31 and the hollowed groove 36. But, as liquid fuel becomes accumulative in the groove 36 vaporization of the liquid fuel is expedited by providing a cooling water duct close to the groove 36.

Description

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

A helical intake port usually has a spiral part formed around the intake valve, and a spiral part tangential to this spiral part. & an inlet passageway which is connected and extends 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. To solve this problem, a helical intake port is branched from the inlet passage. A helical type opening/closing valve is formed inside the metal cylinder, which communicates with the end of the spiral part of the spiral part, and the opening/closing valve is covered with gold film inside the branching passage so that the opening/closing valve opens during high-speed, high-load operation of the engine. An intake port has already been proposed by the applicant. With this helical type intake port, part of the intake air sent into the helical type intake port inlet passage when #i engine is at high speed and under high load is sent into the helical type intake port hooked part through the branch passage. The flow path cutoff 11111& of the intake air increases, 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. This limits the cross-sectional area of the artificial passageway, making it difficult to obtain a sufficiently satisfactory filling efficiency. Historically, the helical type intake port itself has a typical shape, and if a branch pipe that is completely independent from the inlet passage is attached, the overall structure of the intake port becomes extremely complicated. It is quite difficult to form a helical intake port with a branching path in a cylinder head. The object of the present invention is to provide a helical type air port which can obtain high filling efficiency during engine iSIS high-speed loading operation and has a novel shape that is easy to construct.

The present invention will be described in detail below 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 l,
3 is a cylinder head fixed on the cylinder block 1, 4Fi combustion chamber formed between piston 2 and cylinder head 3, 5Fi intake valve, 6 is helical intake port formed in cylinder 3, 7 is an exhaust valve, 8 is a type b in the cylinder head 3! i, a closed exhaust port, '9, a spark plug disposed in the combustion chamber 4, and 1o, a stem guide extending eastward into the stem 5a'i of the intake valve 5, respectively. As shown in FIG. 1 and FIG. A helical intake port 6 consisting of nine connected inlet passage sections A is formed. The partition wall 12#'i extends from inside the artificial passageway section A to around the stem guide 10 of the intake valve 5.
As shown in the figure, the width LFi of the root portion of this partition wall 12 gradually becomes wider as it approaches the stem guide 10 from the artificial feed path section A. The partition wall 12 is the inlet opening 6a of the intake port 6.
The partition wall 12 has a tip 111513t located on the side closest to the tip 1IS13 in FIG. 1
211t+Ii surface 14b extending at 01. The 1st section 1j 14m is from the tip section 13 to the stem guide 10.
The side force of the vortex portion B extends to the vicinity of the llllk surface 15 of the vortex portion B, and a narrow portion 16 is formed between the vortex portion 1ill wall 15 and the vortex portion B. Next, the first side wall curve 14m extends to the stem guide 10 while curving so as to be gradually spaced apart from the spiral portion 1411 and the wall blood 15. - The brim second side wall (3) 14b is extended straight from the tip 13 by the stem guide 101.

Referring to FIGS. 1 to 9, the side wall surface 17.18 of the population fikt part A is vertically arranged,
The earthen wall of A [11119 descends toward the spiral part B in the direction 1y. Population street, side 17r of road section A, Isoichi 1bB17
)llil wall surface 15 and is smoothly connected to the inlet passage section A.
The upper wall surface 19 of the spiral portion B is connected to the earth wall surface 20 of the spiral portion B by a sliding force. The upper wall surface 20 of the spiral portion B gradually narrows in width as it descends from the connection between the spiral sB and the artificial passageway portion A toward the narrowing portion 16, and then gradually widens as it passes through the narrowing portion 16t. As shown in FIG. 5, the lower wall direction 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 portion 21jLFi 8th adjacent to the 1111I wall surface 17 As shown in the figure, as it approaches the spiral NSB, it rises and forms an inclination [10]. This slope I
The inclination angle of the P+ bottom wall surface portion 21m gradually increases as it approaches the spiral sBK.

Part of the first side wall 14m of the partition wall 12 consists of a slightly inclined downward OI groove, and the 21111st wrinkle Ik1
4b is almost vertical. Separation! ! 12 bottoms 122/f
The entrance passage s6 curves downward from the entrance passage sA toward the spiral portion B so that the distance between the entrance passage s6 and the upper wall mxx gradually increases from the tip end 13 toward the stem guide 10. A lip 23 is formed on the bottom wall surface 22 of the partition wrinkle 12 in the area not marked by hatching in FIG. Form an inclined surface.

- 10,000, inside the cylinder head 3 there is a spiral end portion C of the spiral portion B.
A branch w524 is formed that fully communicates with the entrance passage section A,
A rotary 9f25 is arranged at the entrance of this branch path 24. This branch passage 24 is separated from the entrance passage A by the partition wall 12, and the entire lower space of the branch passage 24 communicates with the entrance passage A. The earthen wall 1126 of the branching path 24 has a uniform slope of 1IJk, gradually descending towards the end of the spiral C, and is smoothly connected to the earthen wall surface 20 of the spiral portion B. On the 2111th wall surface 14b of the partition wall 12? There is almost no poisonous blood on the ll1l wall side 27 of the branching path 24 facing J. Historically, this grudge side 27 is located on the top of the wall wall 18 of #1 entrance passage section A. As can be seen from FIG. 1, the lip 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, it is composed of a rotary box 25Fi rotary valve holder 28 and a valve shaft 29 rotatably supported within the rotary valve holder 28, and this rotary valve holder 28 is bored in the cylinder head 3. 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. Valve stem 2
An arm 32 is fixed to the upper WAs of 9. Further, a ring m33 is formed on the outer peripheral surface of the valve shaft 29, and an E-shaped positioning ring 34 is disposed within this ring groove 33. Furthermore, a sealing member 3 is provided at the upper end of the rotary valve holder 28.
5 is fitted over the valve shaft 29, and this sealing member 35 performs a sealing action on the valve shaft 29. - As shown in FIGS. 1, 3, and 7, a conical recess 36 is formed on the resistor surface 21 facing the lower end of the valve body 31.
1Q, the lower end is the wall of the groove 36, or there is a slight interval □ -
C-cm pumping, 6 inside, insertion inside, 81. As shown in FIG. 1, a cooling water passage 37 is formed in the cylinder head 3 near the recess #I36, and the cooling water passage 37 is separated from the thin wall 38t by the cooling water passage 37 along the branch passage 24. .

Referring to FIG. 11, the tip of the arm 32 fixed to the upper four parts of the rotary valve 25 is equipped with a negative pressure diaphragm.
It is connected via a connecting rod 43 to a control rod 42 fixed to a diaphragm 41 of 40. It has a negative pressure chamber 44' isolated from the atmosphere by a negative pressure diaphragm device FIt40Fi diaphragm 41, and a compression spring 45 for pressing the diaphragm is inserted into this negative pressure chamber 44. To the cylinder, ru to Do 3 Primary side carburetor 46m and secondary side carburetor 46
An intake manifold 47 equipped with a compound carburetor 46 consisting of a negative pressure chamber 44 is installed, and a negative pressure chamber 44 is
It is connected to the intake manifold 47 through 48-karat gold. In this negative pressure conduit 48, an intake manifold 47 is connected from the negative pressure chamber 44.
The check valve 49, which can only flow inward, is inserted.

Further, the negative pressure chamber 44 communicates with the atmosphere via an atmospheric conduit 50 and an atmospheric release control valve 51t.

The atmospheric release control valve 51Fi has a negative pressure valve 53 and an atmospheric pressure chamber 54 separated by the diaphragm 52 to the south, and further has a valve chamber 55 adjacent to the atmospheric pressure chamber 54. This valve chamber 55
communicates in part with the negative pressure chamber 44 via an atmospheric conduit 50 and, on the other hand, with the atmosphere via a valve boat 56 and an air filter 57t.

Inside the valve chamber 55 is a valve element 5 that controls opening and closing of a valve port 56.
8 is provided, the valve body 58 being connected to the diaphragm 52 via a valve rod 59. A compression spring 60 for pressing the diaphragm is inserted into the negative pressure i53, and the negative pressure chamber 53 is
1i negative pressure conduit 61t is connected to the pliers 9 part 62 of the primary vaporizer 46m.

The carburetor 46 is a commonly used carburetor, and when the primary throttle valve 63 is opened to a predetermined degree or more, the secondary throttle valve 64 is opened, and when the primary throttle valve 63 is fully opened, the secondary throttle valve 64 is opened. The side throttle valve 64 is also fully opened. The negative pressure generated in the pentuary 1Js62 of the primary side carburetor 46m increases as the amount of intake air supplied to the engine cylinder increases. Therefore, the negative pressure generated in the venturi portion 62 becomes larger than the predetermined negative pressure. When the engine is operated at high speed and under high load, 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 boat 56 and creates negative pressure. Negative pressure chamber 4 of diaphragm @40
4 to the atmosphere. At this time, the diaphragm 41 is moved 10,000 degrees 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. −
If the degree of rotation of the primary throttle valve 63 is small, the negative pressure generated in the pliers 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't. 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 47. When the negative pressure in the intake manifold 47 becomes larger than the negative pressure in the pressure chamber 44 of the negative pressure diaphragm device 140, the check valve 49 closes and the negative pressure in the intake manifold 47 becomes negative in the negative pressure chamber 44. When the pressure becomes smaller than the pressure, the valve opens, so as long as the atmospheric release control valve 51 is open, the negative pressure chamber 4
The negative pressure within the intake manifold 47 is maintained at the maximum negative pressure developed within the intake manifold 47. When negative pressure is applied within the negative pressure chamber 44, the diaphragm 41 rises 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 operating at low speed and low load, the rotary valve 25 closes the branch passage 24. Furthermore, if the machine rotation speed is low even during high load operation, or if the engine rotation speed is high but low negative operation is being performed, the negative pressure generated in the pliers and the rim 62 will be reduced. Because of the small size, the atmosphere-discharge valve 51 continues to be closed. Therefore, during such low-speed, low-load operation and high-speed, low-load operation, the negative pressure chamber 44
Since the negative pressure inside is maintained at the maximum negative pressure mentioned above, 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 when there are few intake air caps. At this point, part of the air-fuel mixture sent into the inlet passage section A advances along the earthen wall i1i [i19.20, and part of the remaining air-fuel mixture crashes into the rotary valve 25. At the end of the side wall surface 17 of the entrance passage gA
Proceed along one wall 15 of . −11 As mentioned above, earthen wall i
+ij of &I19.20 gradually narrows as it approaches the narrowed part 16, so the flow path of the air-fuel mixture flowing along the upper wall surface 19.20 gradually narrows, thus upward! ! The air mixture flow along planes 19° and 20 gradually increases in speed. Furthermore,
As mentioned above, the first quasi kjtm 14 m of the partition wall 12 extends to the vicinity of the l114 wall ij[i15 of the spiral part B, so the mixed air flow that advances along the soil wall surface 19.20 is caused by the 1411 wall surface 15 of the spiral part B. pushed up and then l1ll
In order to proceed along the wall surface 15, a strong swirling flow is generated within the volume a MB. The mixture then swirls and passes through the gap formed between the intake valve 5 and its valve limbs into the combustion chamber 4.
and generates a strong swirling flow within the combustion chamber 4. In this way, when the engine is running at low speed and in the negative direction, the air-fuel mixture collides with the valve element 31, so if the gap between the lower end of the valve element 31 and the bottom wall TH121 is completely over, the gum accumulated in the air-fuel mixture will be removed. Such impurities accumulate on the lower gtA portion of the valve body 31, causing a problem that the valve body 31 is stuck to the bottom wall surface 21. In order to avoid Mk during such a period, a gap is provided between the lower part of the valve body 31 and the bottom wall surface 21, but if this gap is only provided with a single fc, the air-fuel mixture will pass through 1Ijt during this time and leak, resulting in a vortex II. !
The swirling flow generated in part 1B will be stung.

Therefore, in the present invention, a concave portion 36t'' is formed on the bottom wall surface 2.1, and a seal is formed between the tip of the valve body 31 and the concave groove 36 to prevent gum-like impurities from accumulating. However, when the groove 36 is formed on the bottom wall surface 21 in this way, a problem arises in which liquid fuel accumulates in the groove 36. In the invention, since the cooling water passage 37 is provided adjacent to the recess #36, the vaporization of the liquid fuel accumulated in the recess #36 can be promoted by the cooling water.

Historically, since this cooling water passage 37 extends along the branch passage 24, the vaporization of the liquid fuel flowing on the bottom wall surface 21 is also promoted.

The rotary valve 25 is partially opened during high-speed, high-load operation of the engine with a large amount of intake air, so the air-fuel mixture sent into the inlet passageway A is roughly divided into three streams. That is,
The first flow is a mixed air flow that flows between the 111411 wall surface 14m of the partition wall 12 and the 1411 wall surface 17 of the inlet passage section A, and then flows while swirling along the upper wall surface 20 of the swirl section A. is a mixed air flow that flows into the swirl portion B via the branch passage 24', and the third flow is a mixed air flow that flows into the swirl portion sB along the bottom wall surface 21 of the inlet passage portion A.

The flow resistance of the branch path 24 is M11411 wall 1i 14 a
and I[e, compared to the flow resistance between the surfaces 17, and therefore the second mixed air flow is larger than the first mixed air flow.

Further, the flow direction of the first air mixture flowing while rotating by 1kk in the spiral portion B is deflected downward by the second air mixture,
In this way, the swirling force of the first air mixture flow is weakened. In this way, the flow resistance of the mixture air flow from the small branch passage 24 increases, and the flow direction of the mixture air flow is further deflected downward, so that there is still light flow.

This results in greater efficiency. In addition, as mentioned above, since the bottom wall surface of the partition l121 is carved from a downwardly inclined surface, the third air-fuel mixture riL#'i is directed eastward in this 91 direction, and the flow direction is deflected downward. As a result, even higher filling efficiency can be obtained.

Further, the helical type intake port according to the present invention can be easily manufactured because the partition wall 12 may be integrally formed on the upper wall surface of the intake port 6.

As described above, according to the present invention, when the engine is running at low speed and low impact, the branch pipe is shut off and a large amount of air-fuel mixture flows along the soil wall surface of the volute part, thereby generating a strong swirling flow inside the combustion chamber. be able to. On the other hand, when the engine is operated at high speed and under high load, by opening the branch passage, the mixed air-fuel mixture is sent into the volute through the branch passage with low flow resistance, so that a higher filling efficiency can be obtained. In addition, by forming a concave #1 on the hot air port resistor wall surface and forming a labyrinth seal between this concave groove and the lower part of the valve body of the rotary valve, it is possible to prevent the accumulation of impurities such as gum and to maintain the air-fuel mixture. Furthermore, by providing a cooling water passage near the groove, vaporization of the liquid fuel leaked into the groove can be promoted.

[Brief explanation of drawings]

FIG. 1 is a side sectional view of an internal combustion engine according to the present invention taken along line 11 in FIG. 2, FIG. 2 is a plan sectional view taken along line FIG. 4 is a side view schematically showing the shape of the helical intake port according to the invention, FIG. 4 is a plan view schematically showing the shape of the helical intake port, and FIG. A cross-sectional view taken along the rock, Figure 6 is II taken along the ■-■ edge of Figures 3 and 4.
T-side view, Figure 7 is a sectional view taken along the ■-■ string in Figures 3 and 4, and Figure 048 is 1- in Figures 3 and wJ4.
■FcIIT side view taken along the line, Figure 9 is a cross-sectional view taken along -IXm in Figures 3 and 4, Figure 10 is a side sectional view of the rotary valve, and Figure 11 is the rotary valve. It is a diagram showing a valve drive control I41 device 11t. 4... Combustion chamber, 6... Helical intake port, 12
... Partition wall, 24 ... Branch passage, 25 ... Rotary valve, 36 ... Concave groove, 37 ... Cooling water passage. W/! , Figure 1! 152 Figure 7 Figure 81! l No. 101

Claims (1)

[Claims] In a helical intake port that is configured with a spiral portion formed around the intake valve and an inlet passage portion that is tangentially connected to the spiral S and extends almost straight, the helical intake port is branched from the inlet passage portion. A branch passage communicating with the end of the winding * of the spiral part is attached to the inlet passage part, projects downward from the upper wall surface of the intake port, and is connected to the branch passage by a partition wall that is assembled from the inlet passage part to the circumference 9 of the intake valve stem. is separated from the entrance passage, and the entire lower space of the branch passage communicates with the entrance passage in the cross section, and the passage walls of the station entrance passageway and the branch passage are integrally connected. An on-off valve t installed in the branch path from the direction m of the branch road to the top of the lower wall surface of the branch path is provided, and the intake air flow tfilJ14L flows through the branch path by the on-off valve.
Further, a helical intake port is provided with a groove for receiving the lower end of the opening/closing valve O on the lower wall surface of the branch passage, and a cooling water passage is formed adjacent to the groove.