JPS6275022A - Diesel combustion chamber - Google Patents

Abstract

PURPOSE:To reduce smoke, NOX, HC, and noise by providing a partition member which covers the center part of the top opening part of a combustion chamber which is formed in the hollow part formed on the top of a piston, and forming a throttle part between said partition member and the edge of said opening part. CONSTITUTION:In a piston 3, a combustion chamber 7 is formed in a deep hollow part on a piston top part 6, and the edge 8 of an opening part is extended out, in a lip form, toward the center of the combustion chamber 7. A partition member 10 is provided in the combustion chamber 7. The partition member 10 is erected from the bottom part of the combustion chamber 7, and its upper part is formed so as to cover the center part 7a of the opening while forming a throttle part 12 having a proper gap (t). Thereby, smoke, NOX, HC, and noise can be reduced.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a direct injection diesel combustion chamber, and more particularly to a diesel combustion chamber that creates a strong toroidal flow that improves the mixing properties of intake air and injected fuel oil within the combustion chamber. .

[Prior Art] Generally, fuel oil is directly injected into a combustion chamber formed at the top of a piston to cause spontaneous ignition combustion.
A proposal described in Japanese Patent No. 5-127835 is known.

The above proposal shown in FIG. 9 includes a cap 20 that covers the fuel injection side of the fuel injection nozzle 5a hanging from the cylinder head 2 and forms an appropriate gap to introduce the squish TI generated by the piston 3a. It is provided integrally with the cylinder head 2, and the cap 20 has a hole 21 through which the fuel oil injected from the fuel injection nozzle 5a passes.

[Problems to be Solved by the Invention] In short, the above proposal introduces into the cap 20 the high-temperature skid 11 plates generated during the piston compression process, while
At the end of compression of the piston 3a, a toroidal flow 2 is created in the combustion chamber 7b, and the cap 20
The fuel oil, which has been partially ignited, is rapidly re-burned in the combustion chamber 7b to improve Nox, Hc, and smoke.

However, since the piston 3a starts to descend at the same time as the combustion, the combustion gas in the combustion chamber 7b suddenly flows into the cylinder 4.
It will be opened within. That is, the cylinder internal pressure rises rapidly, leaving a factor that increases engine noise, and the flame and toroidal flow T2 in the combustion chamber 7b
This leaves the problem of incomplete combustion and ignition delay, which is another noise factor.

[Object of the invention] The present invention aims to solve the above problems,
To provide a tasel combustion chamber capable of completing combustion within the combustion chamber and creating a strong toroidal flow for improving combustion within the combustion chamber to reduce smoke, NOx, HO, and noise. With the goal.

[Summary of the Invention] In order to achieve the above object, the present invention forms a constriction part in the upper opening of the combustion chamber recessed in the top of the piston, covering the center thereof and between the opening edge and the upper opening of the combustion chamber. This device is equipped with a partition member, which increases the flow velocity by forcing the intake air into the combustion chamber through compression of the piston, especially through the constriction part, and generates a strong toroidal flow inside the combustion chamber, which facilitates the mixing of fuel oil and intake air. The aim is to improve the combustion characteristics and reduce the noise level.

[Embodiment] A preferred embodiment of the diesel combustion chamber of the present invention will be described below with reference to the accompanying drawings.

In FIG. 1, 1 is a cylinder body, 2 is a cylinder head, 3 is a piston that can freely move back and forth within the cylinder body 1, 4 is a cylinder defined by the cylinder body 1 and cylinder head 2, and 5 is a fuel injection nozzle. It is.

As shown in the figure, the screw 1-3 has a piston top 6.
A combustion chamber 7 is formed by deeply recessing the combustion chamber 7, and an opening edge 8 of the combustion chamber 7 extends in a lip shape toward the center of the combustion chamber 7.

The inner peripheral wall 9 of the combustion chamber 7 forms a smooth continuous surface,
The circumferential wall 9a is formed into a spherical depression.

Therefore, the lip-shaped opening edge 8 is formed as a squish lip that generates a squish toward the center of the combustion chamber 7, and the combustion chamber 7 is formed as a combustion chamber that generates a toroidal flow.

Now, the features of the diesel combustion chamber of the present invention are that it further strengthens the toroidal nozzle □ to improve the mixing of fuel and intake air, and achieves reliable combustion within the combustion chamber so that no combustion occurs. Things (Hc, NOX.

The aim is to eliminate smoke (smoke) and reduce noise through stable combustion.

Therefore, a partition member 10 is provided within the combustion chamber 7.

The partition member 10 is formed in a flared shape and has a bottom portion 11.
is provided to stand up from the bottom of the combustion chamber 7, and its radially enlarged upper part is provided so as to cover the upper opening center part 7a of the combustion chamber 7, and has a radius between it and the opening edge 8. A constriction portion 12 is formed that forms an appropriate gap in the direction.

Further, the lower side of the partition member 10 is formed into a spherical shape symmetrical to the peripheral side wall 9a of the combustion chamber 7.

Therefore, the partition member 10 formed in this way is
As shown in FIGS. 3 and 4, the combustion chamber 7 is formed into a doughnut-shaped space, and the intake air, which is forced through the throttle part 12 and has a high flow rate, swirls in the radial direction of the combustion chamber 7 and circles. A strong toroidal flow T2 rotating in the circumferential direction is generated in the combustion chamber 7.

In the embodiment, when the partition member 10 is provided in the combustion chamber 7, the partition member 10 is installed as shown in FIG.
For tightening, insert a bolt 14 into the through hole 13 that opens from the enlarged diameter center part of the upper part, that is, the center of the inverted conical part 17 and penetrates on the axis of the lower part. It is configured to tighten. In this case, the partition member 10
is made of the same material as the piston 3, or of highly heat-resistant ceramic, Nimonics, SUS alloy, etc.

The method of installing the partition member 10 is not limited to the above method, and casting or monolithic casting (lost 1 knock-off) is also possible.

Next, the configuration for supplying fuel oil into the combustion chamber 7 will be described.

In this embodiment, the fuel injection nozzle 5 has the following features as shown in FIG.
As shown in Fig. 2, four jets 15 are provided, from which fuel is jetted. On the other hand, the finishing member 10t
In this case, a fuel guide portion 16 cut out in, for example, a semicircular shape is provided at a portion facing the above-mentioned 8 injections [] 15 on the side of the edge 8 of the L section in the meantime, so as not to obstruct the injected fuel oil. It is formed. Therefore, each injection port 15 of the fuel injection nozzle 5 is
Opening of the combustion chamber 7 via the fuel guide part 16] The spray from each nozzle 15 faces the inner wall 9a of the combustion chamber 7 below the edge 8, and part of it collides and scatters, and the rest forms a fuel film Fl that flows downstream along the inner circumferential wall 9a of the combustion chamber together with the above-mentioned herooidal flow T+.

This fuel film [I is evaporated in proportion to the rise in fuel wall temperature, and mixes with the intake air in the combustion chamber 7 to form fuel vapor @F that is easily ignited.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The operation of embodiments of the present invention will be described below with reference to the accompanying drawings.

As shown in Fig. 5, of the 8 injection i1F injected from #4 fuel injection nozzle 5, the outer shell part excluding 4-flow flows into the main stream tt.
Since the cutting force is weak, the inverted conical part 1 of the cutting member 10 is
Distributed around 7. Since this distributed spray F2 has a small fuel particle size, it is instantaneously evaporated by the skifushi 1 king 1.

Therefore, the ignition of the teasel combustion chamber of this embodiment is performed near the fuel guide portion 16 of the cutter member 10 as shown in FIG. It is further propagated to the fuel vapor layer formed by wall evaporation of the fuel film Fl as shown in FIG. Since the fuel is in a state where it is easy to ignite and burn at -11 italf [-1-12], rapid combustion occurs here.Therefore, improvements are made in Nox) and smoke.

In addition, steam combustion in the combustion chamber 7 (because one combustion chamber 7 is throttled by the throttle part 12 and the fuel 11 guide part 16),
The flame necessary for combustion in the combustion chamber 7 is prevented from escaping into the cylinder 4, thereby ensuring combustion. From this, combustion continues until the pressure in the combustion chamber increases to a constant level at the point where the piston 3 descends.

When combustion is carried out in the combustion chamber 7 and the internal pressure exceeds a certain value, the throttle section 12 and the fuel guide section 1 are closed as shown in FIG.
Combustion gas E is ejected from 6 to cylinder 4. The combustion gas spewed out by this sword has extremely high energy, so
The drop-shaped HC adhering to the combustion chamber 7 is incinerated at once.

In this way, the diesel combustion chamber 7 of the present invention has the screw 1-
A high i-roidal flow is formed near the end of compression before the upper row point of the piston 3, and as the piston 3 descends,
Since the combustion within the combustion chamber 7 can be stabilized, a sudden rise in pressure within the cylinder 4 can be suppressed to reduce noise, and the combustion energy can be effectively used as engine output energy due to the ejection energy obtained in the later stages of combustion.

[Effects of the Invention] As is clear from the above description, the diesel combustion chamber of the present invention exhibits the following excellent effects.

(1) Since the C1 cutting member is placed 8u in the combustion chamber, it is possible to create a high electric current in the combustion chamber, which improves the mixing of fuel oil and intake air in the combustion chamber. Yes, I can do it.

Nox improvement can be prevented.

(2) The combustion chamber and the partition part A form a constriction part that generates 1·[1 ital flow and holds the combustion gas in the combustion chamber until It reaches a certain value in the combustion chamber. It is possible to contribute to combustion without escaping the flaring flame, and to re-burn smoke and 1-(C) by the ejected combustion gas in the latter stage of combustion.

(3) Since the cylinder internal pressure can be prevented from rapidly increasing, noise can be significantly reduced.

C4) Combustion energy can be effectively used as engine energy.

[Brief explanation of drawings]

Figure 1 shows D1 of the present invention! 2 is a side view of FIG. 1; FIGS. 3 and 4 are diagrams showing the process of generating troutal flow; FIG.
8 are diagrams showing the combustion process of the diesel combustion chamber of the present invention, and FIG. 9 is a schematic sectional view showing a conventional combustion chamber. In the figure, 1 is the cylinder body, 2 is the cylinder head, 3 is the piston, 4 is the cylinder, 5 is the fuel injection nozzle, 6 is the top of the piston, 7 is the combustion chamber, 7a is the -L section open l'', and 8 is the open section. [1 part edge, 10 is a partition member, 16 is a fuel guide part. Patent Applicant: Isuzu Motors Co., Ltd. Representative Patent Attorney Nobuo Kinutani Yusanto] [=・Principal'? ili'1] [intestinal-out (1] formula)
December 411, 1985 Special πF Agency Director Uga Michi Department '1. Display of matter fl Patent Br16(')-214
581 No. 2, Title of the invention Diesel combustion chamber 3, Person making the amendment A'1 Relationship Patent applicant (017) Isu-Zero Jidochu Co., Ltd. 4, Agent Postal Service Co., Ltd. 10F5 Atago, Minato-ku, Middle East 1-6-7 Atago Ill Lawyer Building 5, amendment order! ]I” 1986 Zl-January 2F3F] (Shipping [1) 0,
Drawings subject to amendment 7, Contents of amendment (1) Submit appropriate drawings as shown in the attached sheet. (However, the contents have not been changed)

Claims (2)

[Claims] (1) A diesel combustion chamber characterized in that a partition member is provided in the upper opening of the combustion chamber recessed in the top of the piston, covering the center of the upper opening and forming a constricted part between the opening and the edge of the opening. . (2) The partition member has a flared shape that stands up from the center of the bottom inside the combustion chamber and expands its upper part in the radial direction to form a fuel guide part between it and the edge of the upper opening. A diesel combustion chamber according to claim 1 above.