JPH0143473Y2 - - 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.

Purpose of the invention The object of the 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 passage 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 an 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 connecting rod connected to the actuator is placed above the rotary valve along a line connecting the rotary valves, and a protruding piece having a long hole extending perpendicularly to the connecting rod is placed above the rotary valve. A pin that protrudes from the connecting rod in the same direction as the arm and is attached to the tip of the arm is fitted into an elongated hole, and a spring member that presses the pin toward the connecting rod is attached to the connecting rod.

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 is formed between the heads 3, 5 is an intake valve, 6 is a helical intake port formed in the cylinder head 3, 7 is an exhaust valve, 8 is an exhaust port formed in the cylinder head 3, and 9 is a helical intake port formed in the cylinder head 3. A spark plug placed in the combustion chamber 4; 10 is a stem 5 of an intake valve 5;
The stem guides guiding a are shown respectively. As shown in FIGS. 1 and 2, a partition wall 12 projecting downward is integrally formed on the upper wall surface 11 of the intake port 6, and this partition wall 12 forms a spiral portion B and a tangent line to the spiral portion B. A helical intake port 6 is formed of inlet passages A connected in a shape. 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 has a tip 13 located on the side closest to the inlet opening 6a of the intake port 6,
Further, the partition wall 12 has a first section extending counterclockwise from the distal end 13 to the stem guide 10 in FIG.
It has a side wall surface 14a and a second side wall surface 14b extending clockwise from the distal end portion 13 to the stem guide 10. The first side wall surface 14a passes from the distal end portion 13 to the side of the stem guide 10 to the side wall surface 15 of the spiral portion B.
The constricted portion 16 is formed between the spiral portion side wall surface 15 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 side wall surface 14b extends from the tip 13 to the stem guide 1.
It increases almost immediately to 0.

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 from the connecting part of the sliding part B and the inlet passage part A toward the narrowing part 16 while adjoining the narrowing part 16.
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, the portion a is raised to form an inclined surface. The angle of inclination of this inclined bottom wall surface portion 21a rises as it approaches the spiral portion B, forming an inclined surface. This inclined bottom wall part 2
The inclination angle of 1a 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, a branch passage 24 is provided in the cylinder head 3 that communicates the spiral rear end C of the spiral section B with the inlet passage section A.
is formed, and a rotary valve 25 is disposed at the inlet of this branch path 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 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 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 3 is provided at the upper end of the rotary valve holder 28.
5 is fitted, and this sealing member 35 performs a sealing action on the valve shaft 29.

Referring to FIG. 11, the internal combustion engine has four cylinders arranged in series, namely, the first cylinder, the second cylinder,
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 Honifold 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. 3 cylinders is opposite to the spiral direction of the spiral portion B of the No. 2 and No. 4 cylinders. The direction in which the rotary valves 25 of the 1st and 3rd cylinders should rotate and the 2nd 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 third cylinders are connected to the rotary valves 25 of the second and fourth cylinders with respect to the line connecting the rotation axes of all the rotary valves 25. The arm 32 extends on the opposite side. Each rotary valve 2 is provided above each rotary valve 25.
A connecting rod 41 is disposed extending along a line connecting the actuators 5 to 5, and one end of the connecting rod 41 is connected to a control rod 43 of an actuator 42. The actuator 42 has a negative pressure chamber 45 and an atmospheric pressure chamber 46 separated by a diaphragm 44, to which a control rod 43 is secured. A compression spring 47 for pressing the diaphragm is inserted into the negative pressure chamber 45, and the negative pressure chamber 45 is connected to the intake manifold branch pipe 40a via a throttle 48 and a negative pressure conduit 49. On the other hand, as shown in FIGS. 11 and 12, a protruding piece 50 is integrally formed on the connecting rod 41 above each rotary valve 25, and each of these protruding pieces 50 connects to the arm 3 of the corresponding rotary valve 25.
Projects in the same direction as 2. Each projecting piece 50 has an elongated hole 51 extending perpendicularly to the connecting rod 41, into which a pin 52 attached to the tip of the arm 32 is fitted. This pin 52 is attached to the base 5 as shown in FIGS. 10 and 13.
2a, and a large diameter portion 52 having a smaller diameter than the base portion 52a.
b, and a small diameter portion 52 having a smaller diameter than the large diameter portion 52b.
c and an enlarged head 52d, and a large diameter portion 52b is fitted into the elongated hole 51 so as to be slidable in the axial direction of the elongated hole 51. On the other hand, a leaf spring member 53 is provided for each protruding piece 50, and each leaf spring member 5
One end of 3 is connected to the connecting rod 4 by a rivet 54.
Fixed to 1. On the other hand, the free tip portion 55 of each leaf spring member 53 is formed in an arc shape, and this arcuate tip portion 55 engages with the small diameter portion 52c of the pin 52. Therefore, each pin 52 is constantly pressed toward the connecting rod 41 by the leaf spring member 53, and as a result, each pin 52 is pressed onto the inner wall surface of one side of the elongated hole 51, so that the pin 52 is not pushed inside the elongated hole 51. It can prevent rattling.

During low engine load operation, a large negative pressure is generated in the negative pressure chamber 45, so the diaphragm 44 moves toward the negative pressure chamber 45 against the compression spring 47, and as a result, 1
The rotary valves 25 of the No. 2 and No. 3 cylinders are rotated counterclockwise, and at the same time, the rotary valves 25 of the No. 2 and No. 4 cylinders are rotated clockwise. will be closed. On the other hand, during high engine load operation, the negative pressure chamber 4
diaphragm 44 because the negative pressure inside 5 is reduced.
is moved toward the atmospheric pressure chamber 46 by the spring force of the compression spring 47. As a result, the rotary valves 25 of the first and third cylinders rotate clockwise, the rotary valves 25 of the second and fourth cylinders rotate counterclockwise, and each rotary valve 25 branches into a corresponding branch. Road 24 is fully opened. Note that while the rotary valve 25 is rotated in this manner, each pin 52 slides into the elongated hole 51 while being pressed by the leaf spring member 53, and each pin 52 moves along an arcuate path. I understand.

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 the 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 part B via the branch passage 24, and the third flow is a mixture flow that flows into the bottom wall surface 21 of the inlet passage part 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.

Effect 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 simultaneously rotated in opposite directions using a simple structure using one connecting rod. be able to. In addition, since the pin is constantly pressed against the inner wall surface of one side of the elongated hole by the leaf spring member, no looseness occurs, thus accurately holding the rotary valve at a predetermined opening position. be able to.

[Brief explanation of drawings]

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.
Figure 0 is a side sectional view of the rotary valve, Figure 11 is a plan view of the internal combustion engine, Figure 12 is an enlarged view of the 2nd and 3rd cylinders in Figure 11, and Figure 13 is the rotary valve arm and connection. FIG. 3 is a perspective view showing the connected state of the rods. 4... Combustion chamber, 6... Helical intake port,
12... Bulkhead, 24... Branching path, 25... Rotary valve, 32... Arm, 41... Connection rod, 4
2... Actuator, 50... Projecting piece, 51...
...Elongated hole, 52...Pin, 53...Plate spring member.

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 spiral 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 connecting rod connected to the actuator is placed above the rotary valve along a line connecting the rotary valves, and a protruding piece having a long hole extending perpendicularly to the connecting rod is placed above the rotary valve. An internal combustion engine in which a pin protruding from the connecting rod in the same direction as the arm and attached to the tip of the arm is fitted into the elongated hole, and a spring member is attached to the connecting rod to press the pin toward the connecting rod. Intake control device.