JPS6123618Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a glow plug mounting structure for a swirl chamber type diesel engine, and first, a conventional example thereof will be explained with reference to FIGS. 5 to 8.

In the figure, 1 is the main combustion chamber of the diesel engine,
2 is a swirl chamber, 3 is a throat (communication passage) connecting the two chambers, 4 is a fuel injection nozzle, and 5 is a shell-shaped glow plug. The vortex chamber 2 has an axial center (ball center)
With respect to O, it is formed into a substantially spherical shape.

30 is the axis passing through the center of the throat 3, 40
is the axial center of the nozzle of the fuel injection nozzle 4 (ie, the axial center of the spray), and 50 is the axial center of the glow plug. Note that the diagonal line 40-a indicates the spray range.

The axis 40 of the injection nozzle 4 and the axis 3 of the throat 3
0 are substantially on the same axis when viewed from the vertical plane of the swirl chamber 2 (see FIG. 7). Of course, the same thing can be said when viewed from the plane of Figure 8.

The glow plug 5 has an axis 50 that is parallel to a vertical line L passing through the spherical center O (generally a line parallel to the cylinder axis (not shown)) when viewed from the side of the swirl chamber 2 as shown in FIG. It is arranged so that it is tilted,
Further, as shown in FIG. 7, when viewed from the rear surface of the vortex chamber 2, it is arranged on the same line or parallel to the vertical line L. The arrangement of the glow plug in FIG. 7 is such that its axis 50 is aligned with the nozzle spray axis 40.
It can be said that it is substantially parallel to the plane P passing through the axis 30 of the throat.

In this specification, "viewed from the side of the vortex chamber" refers to the central axis of rotation of the vortex (as seen from the side of the vortex chamber), which passes through the axis O of the vortex chamber 2, as shown in FIG. 5 and 1) and parallel to the vertical line L, and "viewed from the vertical plane of the vortex chamber" means As shown in FIG. 7 (the same applies to FIG. 3, which will be described later), this means viewed from a plane perpendicular to the side surface and parallel to the perpendicular line L.

Compressed air flowing from the main combustion chamber 1 through the throat 3 swirls around the spherical center O in the swirl chamber 2 as shown by the arrow. Fuel is injected from the fuel injection nozzle 4 substantially along this swirling flow, and a portion of this spray directly collides with the glow plug 5.

By the way, as mentioned above, the glow plug 5 is particularly arranged parallel to the plane P as shown in FIG. 7, so as shown in FIG. 6 and FIG. It's out of the way.
Therefore, the swirling flow (vortex flow) of the fuel is not disturbed much, so a large difference occurs in the fuel distribution between the vicinity of the inner wall in the swirl chamber 2 and the vicinity of the ball center O.
It has the disadvantage that it is difficult to achieve good combustion.

On the other hand, Japanese Unexamined Patent Publication No. 53-34006 discloses a glow plug mounting structure similar to the above-described example. In the examples shown in FIGS. 1 to 10 in this publication, it is explained that the axis of the glow plug is located on the same plane as the axis of the injection nozzle hole and the frame cup communication passage. Furthermore, in the examples shown in FIGS. 11 and 12, it is explained that they do not exist on the same plane. Although the specific structure beyond these is unknown, it is clear that at least the glow plug does not have any description of how to attach it in a way that actively disturbs the vortex flow. Therefore, it can be said that similar problems exist as far as the attachment of the glow plug is concerned.

The present invention was devised to eliminate such drawbacks, and will be explained below with reference to FIGS. 1 to 4. Note that Figures 1 to 4 are equivalent to Figures 5 to 8.
These figures correspond to the figures, and the same parts are designated by the same reference numerals.

As shown in FIG. 1, the axis 5 of the glow plug 5
0 is inclined with respect to the vertical line L. This point is the same as before.

However, as shown in Figure 2 and below, the axis 50
are arranged at an angle of θ° with respect to the plane P.

That is, the axis 50 of the glow plug 5 is inclined at θ° with respect to the vertical line L when viewed from the plane P, that is, the vertical plane of the swirl chamber 2, and the main body portion of the glow plug 5 is inclined at an angle of θ° from the vertical line L. It protrudes into the swirl chamber 2 so as to be located transversely. For this reason, as shown in FIGS. 2 and 4, the glow plug 5 is positioned in such a way as to obstruct the swirling flow of fuel, which disturbs the smooth flow (see arrow) and causes the fuel to enter the combustion chamber. Since it is possible to prevent it from being concentrated and distributed only on the walls, it is possible to obtain good combustion, improve engine performance, promote exhaust purification,
This provides effects such as noise reduction.

The fuel spray is directed such that at least a portion thereof directly contacts the glow plug. This improves startability and, together with the above-mentioned increased combustion efficiency, provides an overall excellent diesel engine.

[Brief explanation of the drawing]

Fig. 1 is a schematic side view of a combustion chamber showing the glow plug mounting structure of the present invention, Fig. 2 is a sectional view taken in the direction of the arrow in Fig. 1, Fig. 3 is a right rear view of Fig. The top view of FIG. 1 and FIGS. 5 to 8 show the conventional apparatus, and show views corresponding to FIGS. 1 to 4, respectively. Code 1... Main combustion chamber, 2... Whirlpool chamber, 3... Throat, 4... Fuel injection nozzle, 5... Shell type glow plug, 30... Axis center of throat, 40...
Axis center of fuel spray, 50... Axis center of glow plug,
O...center of the vortex chamber, L...vertical line passing through O, P
...A plane passing through the axes 40 and 30.

Claims (1)

[Scope of utility model registration request] The fuel spray axis of the fuel injection nozzle and the axis of the throat of the swirl chamber are arranged on the same axis when viewed from the vertical plane of the swirl chamber, and when viewed from the vertical plane, the shell-shaped glow plug is arranged on the same axis. A vortex type diesel engine, characterized in that the fuel injection nozzle protrudes into the vortex chamber so as to be located across the vortex chamber, and a part of the fuel spray from the fuel injection nozzle comes into direct contact with the glow plug. Glow plug mounting structure.