JPS6124670Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to the intake port of a four-stroke engine, and its purpose is to improve the engine's combustion efficiency and increase output by evenly drawing the swirling airflow generated at the intake port into the combustion chamber.

In order to improve combustion efficiency, the intake port of the engine connects the intake inlet passage tangentially to the circulation generation chamber formed above the intake outlet, and draws the intake air into the combustion chamber while circulating it in the circulation generation chamber, thereby increasing the combustion efficiency. There are some things that have been designed to improve this.

In this case, the force of the intake air sent from the intake inlet passage into the circulation generation chamber is weak and the intake air does not go all the way to the back of the circulation generation chamber, so most of the intake air is on the front side of the intake outlet near the intake entrance passage. It gets sucked into the combustion chamber from the half circumference. Almost no air is sucked in from the inner half of the periphery away from the intake inlet passage. As a result, the airflow within the combustion chamber is disturbed and the combustion efficiency is still poor.

Therefore, in order to eliminate the above-mentioned drawbacks, the inventor of the present invention considered the devices shown in FIGS. 5 to 8 prior to the present invention.

That is, as shown in FIGS. 5 and 6, the intake inlet passage 21 that communicates with the forced circulation generation chamber 20 is made to extend around the circumference of the forced circulation generation chamber 20 and communicate with it, and a part of the intake inlet passage 21 A plate-shaped intake guide 22 is formed protrudingly on the side, and a part of the intake air in the intake inlet passage 21 is also introduced into an intake outlet part 23 on the opposite side to the communication side part between the circulation generation chamber 20 and the intake inlet passage 21. Let it spin.

Further, as shown in FIGS. 7 and 8, the intake guide 22 formed in the intake inlet passage 21 is formed in a cross shape to supply the intake air from the intake inlet passage 21 to the entire circumference of the circulation generation chamber 20. However, it was thought to improve the combustion efficiency by sucking sufficient intake air into the combustion chamber from the entire circumference of the intake outlet 24 evenly. However, in this case, the flow resistance of the intake air passing through the intake inlet passage 21 tends to increase, which is undesirable.

The present invention was proposed in order to solve the above-mentioned drawbacks. Of the passage cross section of the intake inlet passage communicating with the circulation generation chamber, the width is narrowed in the part near the intake outlet, and the width is narrowed in the part farther away. The width is widened to form an elongated shape, and both parts are made to communicate with each other, so that the near side and the far side of the intake inlet passage are connected tangentially to the circumferential side wall of the circulation generation chamber. As a result, the intake air passing through the narrow part is drawn into the front half of the circulation generation chamber, while the intake air passing through the wide part is drawn into the rear half of the circulation generation chamber. By making it wrap around half the circumference, the intake air can be evenly sent into the combustion chamber from the circumference of the intake outlet while being sufficiently circulated around the entire circumference of the circulation generation chamber, and at the same time, the width By forming the wide part of the intake air into an elongated shape and narrowing the intake air passing through this wide part in the circulation generation chamber, this intake air has an extremely strong circulation force and strengthens the swirl. This is to make it possible to do this.

Embodiments of the present invention will be described below with reference to the drawings.

Fig. 1 shows a schematic side view of a water-cooled horizontal diesel engine E. The engine E has a crankcase 2 housing a cylinder 1, a radiator 3 and a fuel tank 4 mounted and fixed on the upper side of the crankcase 2, side by side.

A piston 5 is slidably fitted into the cylinder 1, and a combustion chamber 6 is formed above the piston 5. The upper part of the combustion chamber 6 is covered by a cylinder head 7, and an air cleaner 8 and a muffler 9 are connected to both front and rear sides of the cylinder head 7, respectively.

The intake passage 10 to which the air cleaner 8 is connected is the second
As shown in FIGS. 4 to 4, it consists of a forced circulation generating chamber 11 formed at the end of the intake passage 10 and an intake inlet passage 12, and a forced circulation flow is generated at the intake outlet 13 opened at the terminal end of the forced circulation generating chamber 11. The chamber 11 and the combustion chamber 6 are communicated with each other, and this communication is provided through the intake valve 14.
Intermittent.

Further, the intake inlet passage 12 communicating with the rotational flow generation chamber 11 is tangentially connected to the circumferential wall 11a of the rotational flow generation chamber 11, and gradually increases from the front side surface 7a of the cylinder head 7 to the portion communicating with the rotational flow generation chamber 11. The circulating flow generation chamber 1 is formed so that it becomes narrower.
The width W 1 of the intake inlet passage portion 12a close to the intake outlet 13 of No. 1 is narrow, the width _{W 2 of} the intake inlet passage portion 12b far from the intake outlet 13 is widened, and the shape of the intake inlet passage portion 12b far away is elongated. It is formed in In this way, the peripheral side wall 11a of the circulating flow generation chamber 11
The near side portion 12a and the far side portion 12b of the intake inlet passage 12 are connected in a tangential manner, and the width W1 of the portion 12a on the side close to the intake outlet 13 of the passage cross section of the intake inlet passage 12 is narrowed. If the width W2 of the far side portion 12b is widened, when the intake air, which has been gradually increased in flow velocity and given intake inertia in the intake inlet passage 12, flows into the circulating flow generation chamber 11, the narrow intake passage portion The intake air passing through the circulation flow generation chamber 12a is sent to the front half of the circulation generation chamber 11, and the intake air passing through the widthwise intake passage portion 12b is sufficiently moved to the rear half of the circulation generation chamber 11 by a large centrifugal force. Since the intake air is sent into the circulation flow generation chamber 11
The air is fed uniformly over the entire circumference of the engine, and is then forcefully sucked into the combustion chamber 6 from the entire surface of the air intake outlet 13.

Moreover, when the wide intake passage portion 12b is formed into an elongated shape, the intake air passing through the wide intake passage portion 12b is sent into the circulation generating chamber 11 in a state where it is expanded in the longitudinal direction. Therefore, when this intake air starts circulating along the circumferential side wall 11a of the circulating flow generation chamber 11, the intake air starts circulating along the circumferential side wall 11a while the spread of the intake air is narrowed, so that the intake speed accelerates. be done. Therefore, the acceleration of the intake air sent from the wide intake passage portion 12b increases the turning force of the entire intake air.

In the figure, reference numeral 15 is an exhaust passage communicating with the muffler 9, and 16 is an auxiliary combustion chamber provided in the cylinder head 7.

As described above, in the present invention, the cross-section of the intake inlet passage that communicates tangentially with the peripheral side wall of the circulation generation chamber is formed to be narrow in the part near the intake inlet and wide in the part far away from the intake inlet. , the intake air can be sufficiently circulated from the narrow intake passage to the front half of the circulation flow generation chamber, and from the wide intake passage to the rear half of the circulation flow generation chamber. As a result, the intake air can be evenly drawn into the combustion chamber from the entire surface of the intake outlet, and a well-balanced vortex flow can be generated in the combustion chamber to improve combustion performance.

Moreover, since the wide intake passage is formed into an elongated shape, the acceleration of the intake air flowing in from the wide intake passage allows the entire intake to have a strong swirling force, creating a swirl inside the combustion chamber. can be strengthened.

In addition, since the narrow intake passage portion and the wide intake passage portion are in communication with each other, it is possible to make the two portions independent of each other, or to make a partition wall protrude from between the connecting portions of the two portions. Compared to the above, the ventilation contact area is smaller and no eddy current occurs, so the ventilation resistance is lower and the intake air filling efficiency is higher.

[Brief explanation of the drawing]

FIG. 1 is a schematic side view of a horizontal diesel engine, FIG. 2 is a longitudinal sectional front view of a head block, and FIG.
FIG. 4 shows a partially cutaway perspective view of the main part, and FIGS. 5, 6 and 7 show the head block in a side view.
8 is a longitudinal sectional front view and a side view of a proposed prior to the present invention.
12a, 12b...part 12, 13...air intake outlet, W ₁ ...width of 12a, W ₂ ...width of 12b.

Claims (1)

[Scope of utility model registration request] The intake outlet 13 of the intake passage 10 is connected to the circulation generation chamber 11.
In the cross-section of the intake inlet passage 12 communicating with the circulation generation chamber 11, the width W1 of the part 12a on the side closer to the intake outlet 13 is narrower, and the width W1 on the far side is narrower.
2b is formed into an elongated shape with a wide width W2, and both portions 12a and 12b are formed to communicate with each other, so that the circumferential side wall 11a of the circulation generation chamber 11
An intake port for a four-cycle engine, characterized in that a near side portion 12a and a far side portion 12b of an intake inlet passage 12 are connected in a tangential manner.