JPH0849542A - Combustion chamber for swirl chamber diesel engine - Google Patents

Abstract

PURPOSE:To efficiently generate fine swirls in the swirl chamber of a diesel engine. CONSTITUTION:Axes of at least a pair of auxiliary nozzle holes 6 cross each other in the gap space 13 between the axis 8 of a main nozzle hole 5 and the inner peripheral wall 12 of a swirl chamber 2, auxiliary fluxes 11 can collide with each other at the intersection 14, and the main flux 10 passes near the intersection 14. Since at least a pair of auxiliary fluxes 11 collide with each other and the main flux 10 passes nearby at a large flow speed, many fine swirls are generated between the main and auxiliary fluxes 10, 11 by the flow speed difference, the air utilization factor in the swirl chamber 2 is increased, and the combustion performance of an engine is improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a combustion chamber of a swirl chamber type diesel engine, and provides a combustion chamber capable of strongly promoting generation of a minute swirl of air in the swirl chamber to improve combustion performance.

[0002]

BACKGROUND OF THE INVENTION Generally, in a combustion chamber of a swirl chamber type diesel engine, an injection hole connecting the swirl chamber and the main combustion chamber is formed from a main injection hole and auxiliary injection holes formed on both sides of the main injection hole. The air is swirled into the swirl chamber from the main combustion chamber through the main injection hole and the sub injection hole to effectively mix the air and the fuel.

The subject of the invention is the combustion chamber of a swirl chamber type diesel engine of this type, the basic structure of which is shown in FIG.
Alternatively, as shown in FIG. 6, the cylinder head 1 of the diesel engine E is provided with a swirl chamber 2 and the swirl chamber 2 is communicated with a main combustion chamber 4 through a nozzle hole 3. It is composed of one or more sets of sub-injection holes 6 provided along both the left and right sides of the injection hole 5, and the air in the main combustion chamber 4 flows into the swirl chamber 2 from the main injection hole 5 and the sub-injection hole 6 respectively. This is a type in which a bundle 10 and a sub-flux 11 are formed and flowed in.

[0004]

2. Description of the Related Art As a conventional technique of this type, Japanese Patent Publication No.
As shown in JP-A-7-59410 (see FIG. 6), a pair of auxiliary injection holes 6 and 6 are provided on both sides of the main injection hole 5, and the auxiliary injection hole 6 is provided.
The axes 7 of 7 and 7 intersect each other, and the intersection 5
There is a configuration in which the axial center 8 of the main injection hole 5 is passed over 0, and two sub-fluxes 11 collide with both sides of the main flux 10 in the swirl chamber 2.

[0005]

In the above-mentioned prior art, only two sub-fluxes 11 collide with each other on both sides of the main flux 10 at one point 50 in the swirl chamber 2, and in particular, the main flux 1 with a strong momentum.
Since 0 goes straight and just blows through the inner peripheral wall 12 of the vortex chamber 2, mutual contributions cannot be expected between the main and sub-fluxes, and the promotion of minute air vortices becomes insufficient, resulting in an air utilization rate. There is room for improvement. An object of the present invention is to improve the directionality of a main flux and a sub-flux in a vortex chamber to efficiently generate a minute vortex.

[0006]

Means for achieving the above object will be described below with reference to FIGS. 1 to 5 showing an embodiment. That is, according to the first aspect of the present invention, in the combustion chamber of the swirl chamber type diesel engine having the basic structure, at least one set of the sub-injection holes 6 has their axes 7 close to each other. The inner side wall 12 of the swirl chamber 2 on the side of the injection hole 6 intersects with each other in the gap space 13 so that the sub-fluxes 11 can collide with each other at the intersection 14 of the axial center 7 of the sub-injection hole 6, and the main flux 10 can be intersected. It is characterized in that it can pass near 14.

According to the second aspect of the present invention, in the first aspect of the present invention, two sets of sub injection holes 6 are provided on the right and left sides, and the sub fluxes 11a flowing from the sub injection holes 6a of one set and the sub flows of the other set. Bundle 11b
Front and rear facing spaces 15a between which the main flux 10 is sandwiched
It is characterized in that each of them can collide within 15b.

According to the third aspect of the present invention, in the above-mentioned first aspect, two sets of the sub-injection holes 6 are provided on the left and right sides, and the sub-fluxes 11a flowing from the one set of the sub-injection holes 6a enter the sub-injection hole 6a. It is characterized in that the other sets of sub-fluxes 11b can collide with each other at positions close to each other at positions away from the sub-injection holes 6b.

[0009]

[Action]

(1) In the first aspect of the present invention, at least one set of sub-flux 11 collides with each other and spreads along the inner peripheral wall 12 of the swirl chamber 2, so that the dispersibility of air in the swirl chamber 2 is promoted. Further, since the main flux 10 blows near the sub-flux 11 whose flow velocity has decreased due to the collision with a large flow velocity / flow rate, a turbulent flow occurs between the main and sub-flux due to the difference in the flow velocity, and a minute vortex flow is generated. Occurs a lot. As a result, the fuel and air injected into the swirl chamber 2 are uniformly and well mixed, the air utilization rate in the swirl chamber 2 is increased, and the combustion performance of the diesel engine E is improved.

(2) In the second aspect of the invention, as shown in FIG. 2, a total of five main fluxes 10 and four sub-fluxes 11 flow into the swirl chamber 2. Then, the sub-fluxes 11a of one set collide with each other, and the sub-fluxes 11b of the other set collide with each other, and the main flux 10 having a large flow rate and a large flow velocity blows between the collision points. Turbulence occurs in the facing spaces 15a and 15b before and after the sandwiching, and many minute vortexes are generated. Therefore, the air utilization rate in the swirl chamber 2 is further increased, and the combustion performance of the diesel engine E is improved.

(3) In the third aspect of the invention as well, like the second aspect of the invention, a total of five fluxes flow into the swirl chamber 2. Then, as shown in FIG. 5, a pair of sub-fluxes 11a and 11b collide with each other on the side closer to the sub-injection hole 6 and the side farther from the sub-injection hole 6, and near the respective collision points, the main flux with a large flow rate and a large flow velocity is obtained. Because 10 blows through,
Turbulence occurs on the upstream side and the downstream side of the main flux 10 and a large number of minute eddies are generated. Therefore, the air utilization rate in the swirl chamber 2 is further increased, and the combustion performance of the diesel engine E is improved.

[0012]

【The invention's effect】

(1) In the present invention 1, since at least one set of sub-fluxes collide with each other and the main flux blows near them at a high flow rate,
Many minute vortexes are generated between the main and sub-fluxes. For this reason,
In the swirl chamber, the fuel and air are uniformly mixed, the air utilization rate in the swirl chamber is increased, and the combustion performance of the diesel engine is improved.

(2) In the second aspect of the present invention, the sub-fluxes of the one and the other set collide with each other, and the main flux blows between the collision points, so that a small amount of air is generated in the facing space before and after the main flux. Many eddies are generated. Therefore, the air utilization rate in the swirl chamber is further increased, and the combustion performance of the diesel engine is improved.

(3) In the third aspect of the invention, since one set of sub-fluxes collide with each other on the side close to the sub-injection hole and the side far from the sub-injection hole, a large number of minute vortexes are generated on the upstream side and the downstream side of the main flow. . Therefore, the air utilization rate in the swirl chamber is further increased, and the combustion performance of the diesel engine is improved.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an external view of a swirl chamber base showing Example 1,
1A is an external view seen from the swirl chamber side, and FIG. 1B is an external view seen from the main combustion chamber side. 2A and 2B are explanatory views of the inflow of the main flux and the sub-flux into the swirl chamber, FIG. 2A is an inflow diagram of the swirl chamber in a left side view, and FIG. 2A is an inflow diagram in the front view. Further, FIG. 3 is a longitudinal sectional view of a main part of a vertical diesel engine.

As shown in FIG. 3, a swirl chamber 2 is provided in a cylinder head 1 of a vertical diesel engine E, a fuel injection pump 17 is thrust into the swirl chamber 2 from above the cylinder head 1, and the lower surface of the cylinder head 1 is intruded. The swirl chamber base 16 is fitted and fixed toward the swirl chamber 2 from the
And the swirl chamber 2 communicates with the main combustion chamber 4 through the injection hole 3. As shown in FIGS. 1 and 2, the injection hole 3 is composed of a main injection hole 5 and two sets of auxiliary injection holes 6a and 6b provided along the left and right sides of the main injection hole 5, respectively. The swirl chamber base 16 is provided with a total of five injection holes.

As shown in FIG. 1B, in the main injection hole 5 and the sub injection holes 6b, 6b on both the left and right sides that are in contact with the main injection hole 5, a ridge line 18b that divides the injection holes is formed from the main combustion chamber 4 side to the swirl chamber. It is formed so as to disappear on the way to 2. Further, in the auxiliary injection hole 6b and the outermost auxiliary injection hole 6a in the left-right direction that is in contact with the auxiliary injection hole 6b, the ridge line 18a that divides the injection hole is clearly formed without disappearing from the main combustion chamber 4 side to the swirl chamber 2. To be done.

The air supplied to the main combustion chamber 4 through the intake passage of the diesel engine E flows into the swirl chamber 2 while forming a swirl flow, is uniformly mixed with the fuel injected from the fuel injection pump 17, and is ignited. It burns, and again becomes a combustion jet flow into the main combustion chamber 4 and jets out. As described above, when air flows from the main combustion chamber 4 into the swirl chamber 2, the main flux 10 passing through the main injection hole 5 and the sub-fluxes 11a and 11 passing through the sub injection holes 6a and 6a.
a and the sub-fluxes 11b and 11b passing through the sub-injection holes 6b and 6b are separately split into five air fluxes.

That is, as shown in FIG. 2A, the swirl chamber base 1
Out of the sub-injection holes 6 extending through 6, a pair of outermost sub-injection holes 6a
The axial centers 7 of the above are intersected in a gap space 13 between the axial center 8 of the main injection hole 5 and the inner peripheral wall 12 of the swirl chamber 2 on the side where the axial center 8 approaches. Then, as shown in FIG. 2B, the auxiliary injection hole 6
The sub-fluxes 11a passing through a are allowed to collide with each other at the intersection 14 of the axial center 7 of the sub-injection hole 6a, and the main flux 10 is allowed to pass near the intersection 14.

On the other hand, as shown in FIG. 2A, the swirl chamber base 1
Among the auxiliary injection holes penetrating through 6, the axial centers 7 of the pair of auxiliary injection holes 6b on the side in contact with the main injection hole 5 are located closer to the center of the swirl chamber 2 than the axial center 8 of the main injection hole 5. Cross in 21. Then, as shown in FIG. 2B, the sub-flux 11b passing through the sub-injection hole 6b.
The main flux 10 and the main flux 10 are configured to be able to collide with each other at an intersection 19 on the center side of the swirl chamber 2 and to pass near the intersection 19.

As described above, the outermost secondary injection holes 6a, 6a
As one set, the left and right sub-injection holes 6b contacting the main injection hole 5
6b is taken as the other set, and the inflow form of the flux into the swirl chamber 2 in the first embodiment will be outlined. The sub-fluxes 11a flowing in from the sub-injection holes 6a of one set and the sub-flux of the other set. Front and rear facing spaces 1 sandwiching the main flux 10 between the fluxes 11b.
5a and 15b are configured to be able to collide with each other.

Therefore, the function of the combustion chamber of the swirl chamber type diesel engine of the first embodiment will be described. In the first embodiment,
As shown in FIG. 2, one main flux 10 and four sub-fluxes 1
A total of five fluxes of No. 1 flow into the swirl chamber 2. Then, the sub-fluxes 11a of one set collide with each other and the sub-fluxes 11b of the other set collide with each other, and the main flux 10 having a large flow velocity blows between the collision points, so that the main flux is different due to the difference in flow velocity. Opposing spaces 15a and 15 before and after sandwiching 10
Turbulent flow occurs in b, and a large number of minute vortexes 20 are generated. As a result, the fuel and air are mixed uniformly and evenly, and the air utilization rate in the swirl chamber 2 is effectively increased, so that the combustion performance of the diesel engine E is improved.

4 and 5 show a second embodiment of the present invention,
In place of Example 1 in which the sub-fluxes 11 collide with each other in the facing space before and after the main flux 10 is sandwiched, in Example 2, the sub-fluxes 11 collide with each other on the ventilation upper side and the lower side of the main flux 10. It is configured to allow.

As shown in FIG. 4, in the second embodiment, as in the first embodiment, one main injection hole 5 is formed in the swirl chamber cap 16.
And a total of 5 injection holes of 4 auxiliary injection holes 6 are penetratingly provided. The ridge line 18b between the main injection hole 5 and the sub injection hole 6b in contact with the main injection hole 5 and the ridge line 18a between the sub injection holes 6a and 6b are both clear from the main combustion chamber 4 side to the swirl chamber 2 and do not disappear. Will continue to be formed.

The sub-fluxes 11a flowing from the one set of sub-injection holes 6a located on the outermost side of the swirl chamber mouthpiece 16 are allowed to collide with each other at a position close to the sub-injection hole 6a. Further, the sub-fluxes 11b flowing in from the other set of the sub-injection holes 6b on the side in contact with the main injection hole 5 can collide with each other at a position away from the sub-injection hole 6b.

In the second embodiment, as in the first embodiment,
A total of five fluxes flow into the swirl chamber 2. As shown in FIG. 5, a pair of sub-fluxes 11a and 11b collide with each other on the side closer to the sub-injection hole 5 and the side farther from the sub-injection hole 5, and the main flux 10 having a large flow velocity is generated near the respective collision points. Since it blows through, a turbulent flow is generated on the upstream side and the downstream side of the main flux 10 due to the difference in the flow velocity, and a large number of minute vortexes are generated. Therefore, the air utilization rate in the swirl chamber 2 is effectively increased as in the first embodiment, and the combustion performance of the diesel engine E is improved.

[Brief description of drawings]

FIG. 1 is an external view of a swirl chamber base according to a first embodiment of the present invention, FIG. 1A is an external view seen from the swirl chamber side, and FIG. 1B is an external view seen from the main combustion chamber side.

2A and 2B are explanatory diagrams of inflow of a main flux and a sub-flux into a swirl chamber according to the first embodiment, FIG. 2A is a left side view of the swirl chamber, and FIG. 2A is a front view of the same. Is.

FIG. 3 is a longitudinal sectional view of a main part of a vertical diesel engine.

FIG. 4 is a view equivalent to FIG. 1 showing a second embodiment of the present invention.

FIG. 5 is a view corresponding to FIG. 2 showing the second embodiment.

FIG. 6 is an explanatory view of inflow of a main flux and a sub-flux in a front view of a swirl chamber showing a conventional technique.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Cylinder head, 2 ... Vortex chamber, 3 ... Injection hole, 4 ... Main combustion chamber, 5 ... Main injection hole, 6 * 6a * 6b ... Sub injection hole, 7 ... Axial center of sub injection hole, 8 ... Main injection Axial axis of the hole, 10 ... Main flux, 11.1
1a and 11b ... Sub-flux, 12 ... Inner peripheral wall of swirl chamber, 13 ...
Gap space in the swirl chamber, 14 ... Intersection of the axes of the auxiliary injection holes, 1
5a, 15b ... Opposing space in the swirl chamber, E ... Diesel engine.

Claims (3)

[Claims] 1. A cylinder head (1) of a diesel engine (E) is provided with a swirl chamber (2), and the swirl chamber (2) is communicated with a main combustion chamber (4) through a nozzle hole (3) to inject the jet. The hole (3) is a main injection hole (5) and one or more pairs of auxiliary injection holes provided along both sides of the main injection hole (5).
(6) and the air in the main combustion chamber (4) to the main injection hole (5)
In the combustion chamber of the swirl chamber type diesel engine, which forms the main flux (10) and the sub-flux (11) into the swirl chamber (2) from the sub-injection hole (6) and at least one set of sub-injection Align the axial centers (7) of the holes (6) with each other
The axis (8) of (5) and the swirl chamber on the side where this axis (8) approaches
(2) intersect with the inner peripheral wall (12) in the gap space (13), and the sub-fluxes (11) intersect with each other at the intersection (1) of the axial centers (7) of the sub-injection holes (6).
A combustion chamber of a swirl chamber type diesel engine, characterized in that the main flux (10) can pass near the intersection (14) while enabling collision at (4). 2. Two sets of sub-injection holes (6) are provided on the left and right sides, and the sub-fluxes (11a) flowing from the sub-injection holes (6a) of one set and the sub-flux (11b) of the other set. 2.) The combustion chamber of the swirl chamber type diesel engine according to claim 1, characterized in that they can collide with each other in the front and rear facing spaces (15a, 15b) sandwiching the main flux (10). . 3. Sub-injection holes (6) are divided into left and right two sets, and sub-fluxes (11a) flowing in from one set of sub-injection holes (6a) are close to the sub-injection holes (6a). Position, the other set of side fluxes
The combustion chamber of a swirl chamber type diesel engine according to claim 1, characterized in that the (11b) s can collide with each other at a position away from the auxiliary injection hole (6b).