JPH0143472Y2 - - Google Patents

Description

[Detailed explanation of the idea] Industrial applications The present invention relates to an intake control device for an internal combustion engine.

BACKGROUND OF THE INVENTION A helical intake port typically consists of a spiral formed around an intake valve 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 during low-speed, low-load engine operation 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, branch passages are formed in the cylinder head that branch from the helical intake port inlet passage and communicate with the spiral end of the helical intake port spiral part, and a rotary valve is installed in each branch passage. At the same time, the arms attached to the valve stems of each rotary valve are connected to each other by a common connecting rod, and by actuating this connecting rod with an actuator, each rotary valve can be opened at the same time during engine high-speed, high-load operation. An intake air control device designed to reduce the amount of air is already proposed by the present applicant, as described in, for example, Japanese Patent Laid-Open No. 176320/1983. In an internal combustion engine equipped with this intake control device, when the engine is operated at high speed and under high load, a portion of the air-fuel mixture sent into the inlet passage of the intake port is sent into the volute of the intake port via a branch passage. The cross-sectional area of the flow path is increased, thus high filling efficiency can be obtained.

In this internal combustion engine, the spiral direction of the spiral portion of each cylinder's intake port is the same, and therefore the tips of the arms attached to the valve shaft of each rotary valve are interconnected by one common connecting rod. Each rotary valve can be controlled to open and close at the same time. However, in some cases, it may be necessary to arrange the intake ports of each cylinder so that the spiral directions of their spiral parts are opposite to each other, and in such cases, the rotary valve should be rotated. Since the directions are opposite to each other, it is no longer possible to control the rotary valves simultaneously by simply pivoting one common connecting rod to the tip of each arm.

OBJECT OF THE INVENTION The object of the present invention is to provide an intake control device with a simple structure that can open and close all rotary valves simultaneously when the spiral directions of the spiral portions of the intake ports of each cylinder are different.

Structure of the invention The structure of the invention consists of a spiral part formed around the intake valve, an inlet passage part connected tangentially to the spiral part and extending almost straight, and a spiral part branched from the inlet passage part. It is equipped with a helical intake port consisting of a branch part that communicates with the terminal end, and a rotary valve that controls the opening and closing of the branch passage is placed in the branch passage, and the tip of the arm attached to the valve shaft of the rotary valve is installed in the branch passage. In an internal combustion engine connected to an actuator and in which the spiral directions of the spiral parts of at least a pair of cylinders are opposite to each other, the arms of the rotary valves provided in the pair of cylinders are connected to the rotary valves in opposite directions with respect to a line connecting each rotary valve. a first line extending substantially parallel to each other on both sides of a line connecting the rotary valves;
arranging a connecting rod and a second connecting rod, pivotally connecting an intermediate portion of the first connecting rod to the tip of one arm, and pivotally connecting one end of the second connecting rod to the tip of the other arm; One end of the first connecting rod is connected to the actuator, and the other end of the first connecting rod is connected to the other end of the second connecting rod via a loose connecting mechanism consisting of a pin and an elongated hole.

Embodiment Referring to FIGS. 1 and 2, 1 is a cylinder block, 2 is a piston reciprocating within the cylinder block 1, 3 is a cylinder head fixed on the cylinder block 1, and 4 is a piston 2 and a cylinder. A combustion chamber formed between the heads 3, 5 an intake valve,
6 is a helical intake port formed in the cylinder head 3, 7 is an exhaust valve, and 8 is a cylinder head 3.
Reference numeral 9 indicates an ignition plug disposed within the combustion chamber 4, and reference numeral 10 indicates a stem guide for guiding the stem 5a of the intake valve 5. As shown in FIGS. 1 and 2, the upper wall surface 1 of the intake port 6
A partition wall 12 projecting downward is integrally molded on the top of the helical intake port 6, which consists of a spiral portion B and an inlet passage portion A tangentially connected to the spiral portion B. be done. This partition wall 12 extends from inside the inlet passage part A to around the stem guide 10 of the intake valve 5, and as can be seen from FIG. It gradually becomes wider as you approach. The partition wall 12 is the inlet opening 6 of the intake port 6.
The partition wall 12 further includes a first side wall surface 14a extending counterclockwise from the tip 13 to the stem guide 10 in FIG. 2, and a first side wall surface 14a extending clockwise from the tip 13 in FIG. and a second side wall surface 14b extending to the stem guide 10. The first side wall surface 14a 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 14a and the spiral portion side wall surface 15. Next, the first side wall surface 14a extends to the stem guide 10 while being curved so as to be gradually spaced apart from the spiral portion side wall surface 15. On the other hand, the second
The side wall surface 14b extends from the tip 13 to the stem guide 10.
It extends almost immediately.

Referring to FIGS. 1 to 9, the inlet passage section A
The side wall surfaces 17, 18 of are arranged substantially vertically, while
The upper wall surface 19 of the inlet passage section A gradually descends toward the spiral section B. The side wall surface 17 of the inlet passage section A is smoothly connected to the side wall surface 15 of the spiral section B, and the upper wall surface 19 of the entrance passage section A is smoothly connected to the upper wall surface 20 of the spiral section B. The upper wall surface 20 of the spiral part B gradually narrows in width while descending from the connection part between the spiral part B and the inlet passage part A toward the narrowing part 16, and then gradually narrows in width.
After passing 6, the width gradually increases. On the other hand, as shown in FIG.
As shown in FIG. 8, as it approaches the spiral portion B, it rises to form an inclined surface. The angle of inclination of this inclined bottom wall surface portion 21a gradually increases as it approaches the spiral portion B.

On the other hand, the first side wall surface 14a of the partition wall 12 is a slightly downwardly inclined surface, and the second side wall surface 14b is substantially vertical. Bottom wall surface 2 of partition wall 12
2 descends from the inlet passage A toward the spiral part B while being slightly curved so that the distance from the upper wall surface 11 of the inlet passage A gradually increases as it goes from the tip 13 to the stem guide 10. Bulkhead 1
A rib 23 protruding downward from the bottom wall surface 22 is formed on the bottom wall surface 22 of No. 2 in the area indicated by hatching in FIG.
forms a slightly curved slope.

On the other hand, in the cylinder head 3 there is a branch passage 24 connecting the spiral end C of the spiral portion B and the inlet passage A.
is formed, and a rotary valve 25 is disposed at the inlet of this branch passage 24. This branch path 24 is connected to the partition wall 12
The branch passageway 24 is separated from the inlet passageway A by , and the entire lower space of the branch passage 24 communicates with the inlet passageway A. 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. Bulkhead 1
The side wall surface 27 of the branch path 24 facing the second side wall surface 14b of No. 2 is substantially perpendicular, and furthermore, this side wall surface 27
is located approximately on an extension of the side wall surface 18 of the inlet passage section A. As can be seen from FIG. 1, the rib 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 rotary valve holder valve 28 is bored into the cylinder head 3. It is screwed into the provided 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 extends from the top wall surface 26 of the branch path 24 to the bottom wall surface 21. On the other hand, an arm 32 is attached to the upper end of the valve shaft 29.
is fixed. Further, a ring groove 33 is formed on the outer peripheral surface of the valve shaft 29, and an E-shaped positioning ring 34 is fitted into the ring groove 33. Furthermore, a sealing member 35 is provided at the upper end of the rotary valve holder 28.
is fitted, and the valve shaft 2 is fitted by this seal member 35.
9 sealing action is performed.

Referring to FIG. 11, an internal combustion engine has four cylinders arranged in series, namely cylinder No. 1, cylinder No. 2,
It has a No. 3 cylinder and a No. 4 cylinder, and the intake port 6 of each cylinder is connected to the corresponding intake manifold branch pipe 4.
0a, 40b, 40c, and 40d. As can be seen from FIG. 11, in this embodiment, the spiral direction of the spiral portion B of the No. 1 and No. 2 cylinders is opposite to the spiral direction of the spiral portion B of the No. 3 and No. 4 cylinders. The direction in which the rotary valves 25 of the 1st and 2nd cylinders should rotate and the 3rd and 4th cylinders
The rotary valve 25 of the numbered cylinder should rotate in the opposite direction. The rotary valves 25 of each cylinder are arranged in a straight line, and the arms 32 of the rotary valves 25 of the first and second cylinders are connected to the rotary valves 25 of the third and fourth cylinders with respect to the line connecting the rotation axes of all the rotary valves. It extends on the opposite side to the arm 32. 1
The distal ends of the arms 32 of the No. 3 and No. 2 cylinders are pivotally connected to a first connecting rod 41, and the distal ends of the arms 32 of the No. 3 and 4th cylinders are pivotally connected to a second connecting rod 42. Therefore, the first connecting rod 41 and the second connecting rod 42 are arranged parallel to each other on both sides of the line connecting all the rotary valves 25. One end of the first connecting rod 41 is connected to a control rod 45 of an actuator 44 via a link 43. The actuator 44 has a negative pressure chamber 47 and an atmospheric pressure chamber 48 separated by a diaphragm 46 to which a control rod 45 is secured. A compression spring 49 for pressing the diaphragm is inserted into the negative pressure chamber 47, and this negative pressure chamber 47 is connected to the throttle 5.
0 and a negative pressure conduit 51 to the intake manifold branch pipe 40a. On the other hand, the first connecting rod 4
1 is connected to the second connecting rod 42 via a loose connecting mechanism 52. Figures 11 and 12
As shown in the figure, a flat plate portion 53 is integrally formed at the end of the second connecting rod 42, and a loose connecting mechanism 52
is formed on the flat plate portion 53 and connected to the second connecting rod 4.
2, and a pin 55 fixed to the end of the first connecting rod 41 and fitted into the elongated hole 54. As shown in FIG. 12, the pin 55 has a small diameter portion 56 that fits into the elongated hole 54, and a washer 57 and a snap ring 58 are attached to the upper end of the pin 55.

During low-load engine operation, large negative pressure is generated in the negative pressure chamber 47, so the diaphragm 46 moves toward the negative pressure chamber 47 against the compression spring 49, and as a result, 1
The rotary valves 25 of the No. 1 and No. 2 cylinders are rotated counterclockwise, and the rotary valves 25 close the branch passage 24. On the other hand, at this time, the loose connection mechanism 5
Since the second connecting rod 42 is pulled by the first connecting rod 41 while the second pin 55 slides in the elongated hole 54, the rotary valves 25 of the third and fourth cylinders are rotated clockwise. As a result, the rotary valve 25 closes the branch passage 24. On the other hand, when the engine is operated under high load, the negative pressure in the negative pressure chamber 47 decreases, so the diaphragm 46 moves toward the atmospheric pressure chamber 48 by the spring force of the compression spring 49. the result,
The rotary valves 25 of the first and second cylinders are rotated clockwise to open the corresponding branch passages 24, and the rotary valves 25 of the third and fourth cylinders are rotated clockwise.
is rotated counterclockwise to open the corresponding branch passage 24. In this way, the first connecting rod 41
By connecting the rotary valves 25 and the second connecting rod 42 to each other via a loose connecting mechanism 52 having a simple structure, the rotary valves 25 of the first and second cylinders can be connected to the third cylinder.
It can be rotated in the opposite direction to the rotary valves 25 of the No. 1 and No. 4 cylinders.

As mentioned above, the rotary valve 25 closes the branch passage 24 when the engine is operating at low load with a small amount of intake air. At this time, part of the air-fuel mixture sent into the inlet passage A advances along the upper wall surfaces 19 and 20, and part of the remaining air-fuel mixture collides with the rotary valve 25 and flows into the inlet passage. After changing its direction toward the side wall surface 17 of section A, it proceeds along the side wall surface 15 of spiral section B. As described above, the widths of the upper wall surfaces 19 and 20 gradually become narrower as they approach the narrowed portion 16, so that the flow path for the air-fuel mixture flowing along the upper wall surfaces 19 and 20 gradually narrows. The air mixture flow along 20 is gradually accelerated. Further, as described above, the first side wall surface 14a of the partition wall 12 has a spiral portion B.
Since it extends to the vicinity of the side wall surface 15, the upper wall surface 1
The air mixture flowing along the spiral portions 9 and 20 is forced onto the side wall surface 15 of the spiral portion B, and then proceeds along the side wall surface 15, so that a strong swirling flow is generated within the spiral portion B. 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 opens, so the inlet passage A
The air-fuel mixture sent into the tank is divided into three main streams. That is, the first flow is a mixed gas flow that flows between the first side wall surface 14a of the partition wall 12 and the side wall surface 17 of the inlet passage section A, and then flows while swirling along the upper wall surface 20 of the spiral section B. The second flow 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 bottom wall section 21 of the inlet passage portion A.
This is a mixed air flow that flows into the spiral part B along .
The flow resistance of the branch path 24 is smaller than the flow resistance between the first side wall surface 14a and the side wall surface 17, and therefore
The number of mixed air flows is larger than that of the first mixed air flow. Further, 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 from the branch passage 24 with low flow resistance increases, and furthermore, the first
Since the flow direction of the mixed gas 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 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. will be obtained.

Effects of the invention Even if the spiral directions of the spiral portions of the intake ports in each cylinder are opposite to each other, the rotary valves can be rotated in opposite directions using a single actuator and a loose coupling mechanism with a simple structure. They can be rotated at the same time.

[Brief explanation of the drawing]

Fig. 1 is a side sectional view of the internal combustion engine according to the present invention taken along the - line in Fig. 2, Fig. 2 is a plan sectional view taken along the - line in Fig. 1, and Fig. 3 is a sectional view according to the present invention taken along the - line in Fig. 2. FIG. 4 is a side view schematically showing the shape of the helical intake port, FIG. 4 is a plan view schematically showing the shape of the helical intake port, and FIG. 5 is a view taken along the - line in FIGS. 3 and 4. 6 is a sectional view taken along the - 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 - line in FIGS. 3 and 4, FIG. 9 is a sectional view taken along the line - in FIGS. 3 and 4, and FIG.
0 is a side sectional view of the rotary valve, FIG. 11 is a plan view of the internal combustion engine, and FIG. 12 is a sectional view taken along line XII-XII in FIG. 11. 4... Combustion chamber, 6... Helical intake port,
12... Bulkhead, 24... Branch path, 25... Rotary valve, 32... Arm, 41... First connecting rod, 42... Second connecting rod, 44... Actuator, 52... Loose connection mechanism .

Claims (1)

[Scope of utility model registration request] A spiral portion formed around the intake valve, an inlet passage portion connected tangentially to the spiral portion and extending almost straight, and a branch branching from the inlet passage portion and communicating with a spiral end portion of the spiral portion. A rotary valve for controlling the opening and closing of the branch passage is disposed within the branch passage, and the tip of an arm attached to the valve shaft of the rotary valve is connected to an actuator. , in an internal combustion engine in which the spiral directions of the overwound portions of at least one pair of cylinders are opposite to each other, the arms of the rotary valves provided in the pair of cylinders extend in opposite directions with respect to a line connecting each rotary valve. A first connecting rod and a second connecting rod are arranged so as to extend substantially parallel to each other on both sides of the line connecting the rotary valves, and the intermediate portion of the first connecting rod is pivoted to the tip of one arm. At the same time, one end of the second connecting rod is pivotally connected to the tip of the other arm, one end of the first connecting rod is connected to the actuator, and the other end of the first connecting rod is inserted through the pin and the elongated hole. An intake control device for an internal combustion engine connected to the other end of the second connecting rod via a loose connecting mechanism.