JPH0478375A - Oil ring for piston - Google Patents

Abstract

PURPOSE:To prevent the generation of waviness and reduce oil consumption by providing a ring groove with plural radial grooves formed deeper than the depth of the ring groove but not to the extent of piercing a piston without providing a radial opening in the peripheral groove between two rails. CONSTITUTION:An oil ring 1 is formed in such a way that two rails 2 divided vertically on the peripheral surface are extended circumferentially but an opening for piercing the peripheral surface 3 between two rails 2 is not formed. A coil spring 4 serving as an expander is mounted to the inner peripheral surface of the oil ring 1. A sing groove 6 is formed at a piston 5, and the oil ring 1 is mounted to this ring groove 6. Grooves 7, radially extended slightly longer than the depth of the ring groove 6 or slightly longer than the radial thickness of the ring 1 but not to the extent of piercing the piston 5, are further formed in plural appropriate positions on the lower side face of the ring groove 6.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an oil ring for a piston, specifically an internal combustion engine,
In particular, it relates to oil rings for pistons in diesel engines.

[Prior art]

Conventionally, as an oil ring for a piston of a diesel engine, an oil ring with a cast iron coil expander shown in FIG. 3A and an oil ring with a steel coil expander shown in FIG. 3B have been used.

In the conventional oil ring 51, an oil passage window 52 is formed in the center of an outer circumferential groove 55 formed between two rails 54 on the circumferential surface. Further, a coil spring 53 is combined as an expander on the back surface of the oil ring 51 in order to enhance the oil scraping action.

A conventional oil ring has a ring groove 5 in which an oil relief hole 58 of a piston 56 is formed, as shown in FIGS. 4A and 4B.
It is installed on 7.

In such a conventional oil ring, the presence of the window 52 causes undulation of the side surface, and this undulation causes a problem in that the sealing of the side surface of the oil ring to the ring groove becomes poor, resulting in an increase in oil consumption.

Furthermore, in conventional oil rings provided with oil passing windows, the strength of the oil ring decreases at the windows, so there is a problem that the oil rings break at the windows during manufacture or use.

In particular, in order to improve the followability of the oil ring to the cylinder wall, it is required to reduce the cross-sectional area of the oil ring, but this is subject to restrictions in terms of strength.

In addition, in the conventional oil ring, oil flows backward from the oil relief hole 58 of the ring groove 57 and flows into the window 52 of the oil ring 51.
There was a problem with it gushing through.

(Problem B to be Solved by the Invention) The present invention solves the above conventional problems and provides an oil ring that consumes less oil! It is set as lH.

[Means to solve the problem]

The present invention solves the above problem in a cast iron or steel oil ring that is installed in a ring groove of a piston and that has two rails on its outer peripheral surface that extend in the circumferential direction of two pieces that make sliding contact with the cylinder wall. The outer peripheral groove formed between the main rails does not have a window penetrating in the radial direction, and the ring groove in which the oil ring is attached is placed at an appropriate position in the circumferential direction on the lower surface of the ring groove. The problem was solved by a piston oil ring characterized by having a plurality of grooves extending in the radial direction that are deeper than the depth of the piston but do not penetrate the piston.

(Operation) According to the present invention, the oil ring installed in the groove of the piston slides on the wall surface of the cylinder due to the reciprocating motion of the piston. At that time, the outer circumferential groove formed between the two upper and lower rails on the outer periphery of the oil ring is not provided with a penetrating window, so the strength is large and the side surface of the oil ring is not undulated. Therefore, the oil ring is installed in the ring groove of the piston while maintaining a good sealing function. The ring groove of the piston has grooves formed on its lower surface at a plurality of suitable positions in the circumferential direction, the grooves extending in the radial direction slightly longer than the depth of the ring groove but not penetrating the piston. Therefore, when the oil ring is attached to the ring groove of the piston and slides back and forth on the cylinder wall, the oil ring does not break or oil comes up, reducing oil consumption. Blow-by gas is increased by forming multiple grooves on the lower surface of the piston ring groove.
It is easy to drain and gas pressure acts on the back of the oil ring, which can prevent premature wear of the oil ring. Furthermore, by eliminating the piston through hole 58, carbon sludge that enters together with the oil does not accumulate around the ring, making it possible to use an oil ring without windows.

〔Example〕

The details of the present invention will be explained based on embodiments shown in the drawings.

The oil ring 1 with a cast iron coil expander shown in FIG. 1A and the oil ring 1 with a steel coil expander shown in FIG. 1B have two vertically divided rails 2 extending in the circumferential direction on the outer peripheral surface. It is formed like this. A coil subring 4 is attached as an expander to the inner circumferential surface of the oil ring 1, in which no window is formed to penetrate the outer circumferential surface 3 between the two rails 2.

As shown in FIGS. 2A and 2B, a ring 7146 is formed on the piston 5, and an oil ring 1 is installed in the ring groove 6. On the lower surface of the ring groove 6, there are grooves extending in the radial direction at a plurality of suitable positions in the circumferential direction, the groove being slightly longer than the depth of the ring groove 6, or slightly longer than the radial thickness of the ring, but not penetrating the piston 5. 7 is formed.

When the above-mentioned oil ring according to the present invention and the conventional oil ring were tested according to the following specifications, results regarding the waviness of the oil ring were obtained as shown in FIG.

Test specifications are engine: 4-cycle 4-cylinder diesel engine Piston outer diameter: 100mm Test conditions: Full load 2500 rpm (10 hours x
Average of 3 tests) Test ring: Top ring Medium 215mm outer circumference barrel face Second ring Medium 2゜5mm outer circumference Tape inner bell oil ring Surface pressure 15kg/cm" (constant) 0.4M on one side during sliding (constant) ) The ring groove of the piston has a diameter of 4mm and a length of 2mm on the bottom side of the groove.
Four Ilffi grooves were provided in the circumferential direction.

In the conventional type oil ring 51 shown in FIGS. 5A to 5C, a window 52 is formed as shown in B, and the test results show that the window 52 is formed as shown in FIG.
The upper surface of the oil ring is as shown in Figure 5A, and the lower surface of the oil ring is as small as 1 to 1, as shown in Figure 5C.
2 pm, resulting in large undulations of 7-10 μm. However, as shown in FIG. 5E, in the oil ring 1 without any windows, the undulations on the upper surface of the oil ring shown in FIG. 5 and the undulations on the lower surface of the oil ring shown in FIG. Both steel oil rings are 0~
It was 1 μm.

The actual results of oil consumption were as shown in FIG.

From Figures 5 and 6, it can be seen that in the conventional oil ring, the oil consumption is doubled in a ring with large undulations compared to a ring with small undulations, but in the oil ring of the present invention, there is almost no undulation, and the oil consumption is reduced. It was almost equivalent to the conventional vest ring.

Since the oil ring of the present invention does not require window processing, manufacturing costs can be reduced accordingly. Conventional oil rings have windows, so increasing the tension with a coil spring will cause more waviness on the sides of the oil ring, but with the oil ring of the present invention, it is possible to increase the tension regardless of the waviness.

When the windowless oil ring according to the present invention is installed in the ring groove of the piston, if there is no oil escape hole in the ring groove, the gas leaking from the top ring and second ring will leak into the oil as shown in Figure 7A. A wide oil ring that is attached to the back side of the ring will receive gas pressure over a wide area, resulting in scuffing. In this case, the gas blows through the groove 7, so that the oil ring is prevented from receiving more gas pressure than necessary, and scuffing is prevented. Also, there was little deposit such as carbon sludge.

〔effect〕

According to the present invention, an oil ring for a piston that does not cause waviness and consumes less oil has been obtained.

[Brief explanation of the drawing]

Figure 1 is a sectional view of an oil ring according to the present invention, A is a sectional view of an oil ring with a cast iron coil expander, B is a sectional view of an oil ring with a steel coil expander, and Figure 2 A is a sectional view of an oil ring with a steel coil expander.
Figure 2B is a cross-sectional view of the piston ring groove, Figure 3 is a cross-sectional view of a conventional oil ring, A is an oil ring with a cast iron coil expander, and B is a cross-sectional view of a piston ring groove.
is a cross-sectional view of an oil ring with a steel coil expander, Figure 4A is a cross-sectional view of a piston ring groove, and Figure 4B is a cross-sectional view of an oil ring with a steel coil expander.
is a developed view of the ring groove, and Fig. 5 is a view showing the waviness according to the test results. D is a diagram showing the undulations on the upper surface of the oil ring of the present invention; E is a diagram showing the circumference of the oil ring; F is a diagram showing the undulations on the lower surface of the oil ring; FIG. FIG. 7 is a diagram showing the consumption amount, and FIG. 7 is a diagram showing the flow of blow-by gas when the oil ring is sliding. A is a cross-sectional view showing the case where there is no oil relief groove, and B is a cross-sectional view showing the ring groove according to the present invention. l...Oil ring 2...Rail 3...
Outer circumferential groove 5... Piston 6... Ring groove 7... Groove Agent Patent Attorney Kuwahara
Eimei Kou I- Graph (A) (B) Graph (A) (B) Graph (A) Graph

Claims (1)

[Claims] A cast iron or steel oil ring that is installed in the ring groove of a piston and has two circumferentially extending rails on its outer circumferential surface that slide against the cylinder wall, and is formed between the upper and lower two rails. There is no window penetrating the outer circumferential groove in the radial direction, and the ring groove in which the oil ring is installed is located at an appropriate position in the circumferential direction on the lower surface of the ring groove, deeper than the depth of the ring groove but to the extent that it does not penetrate the piston. An oil ring for a piston, characterized in that a plurality of grooves extending in a radial direction are formed in the oil ring.