JPH0422039Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to an intake path device for an internal combustion engine, and particularly to an intake path device for an internal combustion engine having a plurality of intake passages for one combustion chamber.

[Prior art]

Conventional intake passage devices of this type have two main and auxiliary intake passages in one combustion chamber, and the main intake passage is equipped with an on-off valve that opens and closes depending on operating conditions. The on-off valve is closed, allowing intake air to flow only through the auxiliary intake passage, and in high-load areas, the on-off valve opens, allowing intake air to flow through both the main and auxiliary intake passages. (Refer to Japanese Patent Application No. 59-81049) By supplying intake air only from the auxiliary intake passage in the low load range, the intake air swirl in the combustion chamber increases and the combustion efficiency is improved, while in the high load range, both the main and auxiliary intake passages Supplying intake air from the engine improves intake air filling efficiency and increases output.

The on-off valve is attached to a valve shaft that passes through both the main and auxiliary intake passages, and a certain gap is formed between the valve shaft and the bearing portion formed on each intake passage partition wall due to assembly problems. There is.

[Problem that the invention attempts to solve]

However, in such a conventional intake passage device for an internal combustion engine, when the intake valve is opened while the on-off valve provided in the main intake passage is closed, the pressure of the combustion gas blown back from the combustion chamber to the intake passage is increased. This acts on the valve, pushing the on-off valve toward the upstream side of the intake air flow, and as a result, the valve stem moves within the gap between the valve stem and the bearing and violently hits the bearing, causing abnormal noise. There was a possibility of doing so.

This idea was developed by focusing on these conventional problems, and even if the on-off valve in the closed state receives backflow combustion gas pressure, it prevents the valve stem from violently hitting the inner surface of the bearing, and prevents abnormalities. The object of the present invention is to provide an intake path device for an internal combustion engine that prevents noise generation.

[Means for solving problems]

To achieve this objective, this invention has a main intake passage and a sub-intake passage connected to one combustion chamber, and an on-off valve provided in the main intake passage that opens during high-load operation of the engine and closes during low-load operation. and,
A valve shaft to which this on-off valve is attached and which forms a gap with the bearing part, and a pressing member that presses this valve shaft toward the combustion chamber and is provided on the intake passage wall on the opposite side of the valve shaft to the combustion chamber. It has the following structure.

[Effect]

In the above configuration, when the engine is under low load, the on-off valve provided in the main intake passage is closed, and when the intake valve opens at this time, the pressure of the combustion gas blown back from the combustion chamber to the intake passage acts on the on-off valve. The pressing member presses the valve stem against the combustion gas pressure,
This prevents the valve stem from violently hitting the inner surface of the bearing.

〔Example〕

Hereinafter, one embodiment of this invention will be described in detail based on FIG. The combustion chamber 3 formed in the cylinder head 1, etc. has an exhaust port 5 on the upper side in the figure.
However, in the figure, intake ports 7 and 9 communicate with each other on the lower side. A first intake manifold 11 communicating with the intake ports 7 and 9 is installed at the lower end of the cylinder head 1 in the figure.
In the figure, a second intake manifold 13 is attached to the lower end. Main intake passages 15 and 17 are formed by these first and second intake manifolds 11 and 13 and intake ports 7 and 9.

A sub-intake passage 21 communicates with the main intake passage 15 on the back side of the first intake manifold 11 in the drawing through an opening 19 .

The first intake manifold 11 on the lower side of the opening 19 in the figure has through holes 23, 23a, 23b, 23c, 23 as bearing parts passing through in the left-right direction.
d and 23e, and a valve shaft 25 is rotatably inserted into the through hole 23. The valve shaft 25 in each main intake passage 15, 17 has a
An on-off valve 27 is attached which rotates together with the valve shaft 25 so as to open the valve 17 when the engine is under high load and close when the engine is under low load. By closing the on-off valve 27 during low load, intake air is supplied only from the auxiliary intake passage 21, increasing intake swirl within the combustion chamber 3 and improving combustion efficiency. On the other hand, when the on-off valve 27 opens under high load, both the main and auxiliary intake passages 15, 17, 21
Intake air is supplied from the engine, improving intake air filling efficiency and increasing output. In addition, the through holes 23, 23a~
Through holes 23a on both left and right ends in the figure of 23e,
A certain gap is formed between the valve shaft 25 and the through holes 23b, 23c, and 23d except for 23e due to assembly problems.

Each main intake passage 1 of the first intake manifold 11
A communication hole 31 is formed in the partition wall (intake passage wall) 29 between 7 and 17, with one end opening toward the lower side of the through hole 23c in the figure, and the other end opening toward the lower end side of the first intake manifold 11. A female threaded portion 33 is formed near the lower opening of the communication hole 31 .
A screw member 35 is screwed into this female threaded portion 33, while a hemispherical nylon cushioning material 37 is housed in the upper side of the communication hole 31.
A spring 41 is housed between the valve shaft 7 and the screw member 35 to urge the buffer member 37 upward in the figure to bring it into contact with the valve shaft 25 . The spring 41 and the buffer material 37 press the valve shaft 25 toward the combustion chamber 3,
It constitutes a pressing member provided on the partition wall 29 of the valve shaft 25 on the side opposite to the combustion chamber 3.

Next, the operation of the device configured as described above will be explained. When the engine is under low load, the on-off valve 27 closes to shut off the main intake passages 15 and 17, and the intake air flows through the auxiliary intake passage 2.
1 to the combustion chamber 3. At this time, when the combustion gas is blown back from the combustion chamber 3 to the intake passage side,
This combustion gas pressure acts on the on-off valve 27 and the valve shaft 25
tries to move to the upstream side of the intake air, that is, downward in the figure, but since the valve shaft 25 is urged by the spring 41 to the downstream side of the intake air, that is, upward in the figure, the combustion gas pressure is transferred to the buffer material 37 and The spring 41 receives it, and the valve shaft 25 receives it through the through holes 23b, 2.
In the figures 3c and 23d, there is no violent collision with the inner surface of the lower side, and even if there is contact, generation of abnormal noise is prevented.

FIG. 2 shows another embodiment. Here, the same reference numerals are attached to the same components as in the above-described embodiment to simplify the explanation. In this embodiment, of the two intake passages 43 and 45 communicating with each combustion chamber 3, the intake passage 45 on the right side in the figure is provided with an on-off valve 27 and is used as a main intake passage, and the intake passage 43 on the left side is used as a sub-intake passage. A pressing member made of a cushioning material 37 or the like is provided on the central partition wall (intake passage wall) 29 in the figure to press the valve stem 25 toward the downstream side of the intake air (upward in the figure). The effects of this embodiment are similar to those of the previous embodiment.

Note that this invention is not limited to the above-mentioned embodiments. For example, by increasing the biasing force of the spring 41 in the embodiments shown in FIGS. 1 and 2, it is possible to prevent the valve shaft from coming into contact with the interior of the bearing on the upstream side of the intake flow.

[Effect of idea]

As described above, according to this invention, the on-off valve is attached and has a valve shaft that forms a gap with the bearing part, and a pressing member that presses the valve shaft toward the combustion chamber.
Because it was installed on the intake passage wall on the opposite side of the valve stem from the combustion chamber,
Even if combustion gas blows back from the combustion chamber when the on-off valve is closed during low engine load and this combustion gas pressure acts on the on-off valve, the pressure member receives this combustion gas pressure, causing the valve shaft to move toward the bearing. This prevents the material from violently hitting the inner surface, and prevents abnormal noise from occurring.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of one embodiment of this invention, and FIG. 2 is an explanatory diagram of another embodiment of this invention. 15, 17...Main intake passage, 21...Sub-intake passage, 25...Valve stem, 27...Opening/closing valve, 37...Buffer material (pressing member), 41...Spring (pressing member).

Claims (1)

[Scope of utility model registration request] A main intake passage and a sub-intake passage each connected to one combustion chamber, an on-off valve provided in the main intake passage that opens during high-load operation of the engine and closes during low-load operation, and a bearing portion to which the on-off valve is attached. An internal combustion engine comprising: a valve stem forming a gap between the valve stem and a pressing member that presses the valve stem toward a combustion chamber and is provided on an intake passage wall on the opposite side of the valve stem from the combustion chamber. Intake path device.