JPS6231614Y2 - - Google Patents

Description

[Detailed explanation of the invention] Pistons with a toroidal combustion chamber are often provided with the combustion chamber at an eccentric position due to the positional relationship of the intake valve, exhaust valve, fuel injection valve, etc. If it is placed at an eccentric position, there will be a side where the squishing effect is stronger and a side where the squishing effect is weaker. In order to ensure good atomization of the fuel despite this deviation in the squishing action, the length (radial dimension) of the lip provided at the periphery of the opening of the combustion chamber must be adjusted, for example, to ensure good atomization of the fuel. As shown in Japanese Publication No. 56-7494, it may be changed as appropriate to generate the optimum swirl for atomization.

The purpose of the present invention is to provide the above-mentioned lip in such a manner that no excessive heat load is applied to the lip, and the present invention will be explained with reference to the drawings as follows.

1 and 2 are respectively a front view and a plan view of a piston according to the present invention, and FIG. 3 is an enlarged view of the combustion chamber portion of FIG. 1. In these figures, reference numeral 1 denotes a toroidal combustion chamber whose centerline Y-Y is offset by an amount indicated by e with respect to the centerline X-X of the piston.

Reference numeral 2 denotes a rib provided at the peripheral edge of the opening of the combustion chamber 1, and hereinafter this rib will be referred to as a squishy rib. The dimensions in the radial direction and the dimension in the depth direction of the squeeze rib 2 are indicated by symbols R and D, respectively. Since the combustion chamber 1 is provided offset to the right by the amount indicated by e, there are two sides on the piston: a side with a strong force 3 and a side with a weak force 4.
Therefore, in relation to this, in the present invention, the radial dimension and the depth direction dimensions R and D of the squeeze rib 2 are both increased from the side 3 where the squeeze is strong to the side 4 where the squeeze is weak. and the respective maximum value Rmax,
Reach Dmax.

Of the dimensions R and D, dimension R is a factor related to the degree of utilization of the squeeze rib, and dimension D is a factor related to preventing excessive heat load from being applied to the squeeze rib due to an increase in dimension R. The tendency for the thermal load applied to the squeezing rib to increase due to an increase in (increase in dimension R) is counteracted by an increase in heat capacity due to an increase in the dimension in the depth direction of the squeezing rib (increase in dimension D),
As a result, a squeezing rib is provided that does not apply an excessive heat load.

The dimensions R and D vary depending on the eccentricity e of the combustion chamber 1. In FIG. 4, the eccentricity e is smaller than in the cases shown in FIGS. 1 to 3, the dimensions R and D are smaller, and the squishing rib 2 does not extend all the way around the opening of the combustion chamber 1, but instead ends in a crescent shape at point P. Indicates the case where it is considered as

As clarified from the above explanation, the present invention provides a squeezing rib in a state where the heat load does not become excessive for a piston having a toroidal combustion chamber at an eccentric position, thereby achieving good atomization of fuel. It is intended to do so.

[Brief explanation of the drawing]

FIG. 1 is a front view showing an example of a piston according to the present invention, FIGS. 2 and 3 are a plan view and an enlarged partial view of the piston shown in FIG.
The figure is a sectional view showing the main parts of another piston according to the present invention. 1... Combustion chamber, 2... Suitable rib, 3...
Side where the tension is stronger, 4... Side where the tension is weaker, R... Radial dimension of the tension rib,
D...Dimension in the depth direction of the stubby rib.

Claims (1)

[Scope of utility model registration request] In a type in which the combustion chamber 1 is provided eccentrically, the radial dimension R and the depth direction dimension D of the rib (squeezing rib) provided at the peripheral edge of the opening of the combustion chamber 1 are on the side where the squishing is weaker than on the side where the squishing is stronger. A piston with a toroidal combustion chamber, characterized in that the combustion chambers are both increased towards the side 4, and the occurrence of overheating due to an increase in the radial dimension R is avoided by increasing the depth dimension.