JPS58206854A - Oil ring structure of engine piston - Google Patents

Abstract

PURPOSE:To prevent oil from leaking from a sliding surface, by forming a given slope at least on one side out of mutually opposing faces of an oil ring and faces touch the opposing faces of the oil ring of a leaf spring pushing the oil ring outward. CONSTITUTION:An oil relief hole 8 is formed on the bottom 7e of an oil ring groove 7 formed on the side of a circumference of a piston 3 and a pair of a top and a bottom oil rings 9a and 9b to be energized outward by a leaf spring 12 whose cross section is in about a U shape is fitted in the groove 7. In this instance, the oil rings 9a and 9b are formed by providing slopes 10a and 10b so that mutually opposing surfaces of the slopes 10a and 10b are expanded mutually toward an inner diametral side. The leaf spring 12 is formed also by providing slopes 14a and 14b touching the above slopes 10a and 10b respectively. In this way, oil is prevented from leaking by converting dragging displacement of the oil rings 9a and 9b into pressing force of the leaf spring 12 and increasing facial pressure against a cylinder wall 2.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the structure of an oil ring in an ennon piston.

Since the oil ring scrapes the lubricating oil layered on the cylinder wall when the piston moves, it must be pressed against the cylinder wall with high surface pressure.

However, such high surface pressure is required when the ennon is rotating freely, and when installing the oil ring into the piston or fitting the piston into the cylinder, the oil ring must be strong in advance to ensure high surface pressure. If a diameter expanding elastic force is applied, there is a problem in that the assembly work becomes extremely difficult.

The present invention has been made based on the above circumstances, and its purpose is to reduce the elastic force for expanding the diameter of the oil ring when assembling the oil ring, and to facilitate the assembly work. Another object of the present invention is to provide an oil ring structure for an engine piston that automatically generates high surface pressure during an oil scraping operation to prevent oil leakage.

In other words, the present invention focuses on the fact that when the piston moves, the oil ring at the front in the moving direction slides on the cylinder wall, so it is dragged by the cylinder wall and is relatively displaced in the opposite direction to the moving direction of the piston. Then, this relative displacement in the opposite direction is transmitted as a force in the diametrical direction to the oil ring on the rear side in the direction of the moving force through the slope formed at least on the side and the oil ring. The surface pressure of the oil ring against the cylinder wall is reduced to prevent oil leakage from the sliding surface, and the oil that collects in front of this rear oil ring is released through the through hole and relief hole.
This feature prevents oil pressure from increasing in the area.

An embodiment of the present invention will be described below with reference to FIGS. 1 to 3.

In the figure, 1 is the cylinder, 2 is ff1l on the inner surface of cylinder 1.
The sagging sleeve essentially creates a shilling. 3 indicates a piston, and 4 indicates a connecting port.

On the circumference 1Ill of the piston 3, image-shaped ring grooves 5 are formed in the head hook, and airtight rings 6 are fitted in these rings h6.

Further, an oil ring holder 7 is formed in the piston 3 closer to the bottom dead center than the airtight ring groove 5 . As shown enlarged in Fig. 2, oil link #$7 has oil relief holes 8 formed in the bottomless surface (groove inner diameter 1il) 7 *, and these relief holes 8 are connected to the piston. It communicates with the crank chamber through the inside of 3. A pair of oil rings 9m and 9b are fitted into the oil ring groove 7 along the reciprocating direction of the piston 3. These oil rings 9m and 9b are spaced apart from each other so that they can move along the moving direction of the piston 3. The surfaces of these oil rings 9 a e 9 b that face each other form inclined surfaces 10 h and 10 b that mutually widen toward the inner side of the tab sill groove 7 (ill 7 c). .The oblique angle θ of these inclined surfaces 10m and 10b is 3 to 1.
O11j, preferably 7 lm degrees. Also, the oil rings 9*, 9b, which are opposite to each other, 11&, 11b are the groove side surfaces of the ring groove 7, the upper surface 7m and the lower surface 7b shown in the drawing.
11*, 11
When b touches upper th17 m and 7b, they are in close contact.

The outer periphery of the oil ring 9 A a 9 b is adapted to come into sliding contact with the cylinder wall 2, and this outer periphery is formed into a barrel face or theno 4 face to reduce the contact surface & with respect to the cylinder wall 2. .

A plate spring J2 is arranged between these oil rings 9&, 9b. The leaf spring 12#'iwhthI has a tiboko-shape, and nine bent legs IJ&, 13 are formed at both ends of the leaf spring 12#'iwhthI.
b pushes the inner peripheral surface of the oil ring 9a*51b outward. Further, this leaf spring 12 is connected to the oil ring 9.
Slope i0JOm of a m'9 b.

It has sloped surfaces 14m and 14b that come into contact with 10b, and the inside diameters 111 of these sloped surfaces 14m and 14b are also widened to form a wedge shape. In the spring 12, there is an oil passage hole 16 that connects the space 15 surrounded by the cylinder wall 2 and both oil rings 9ma9b with the relief hole 8.
・is formed.

Figure 3 is added to explain the operation of 711 actual examples of such a configuration.

During operation of the engine, for example, when the piston 3 is moved toward the bottom dead center, in the direction of arrow A in FIG. Therefore, due to friction with the cylinder wall 2, both oil rings 9m and 9b are dragged in the direction of arrow B relative to the piston 3.

In the nine oil rings on the upper side of the figure, the back surface IIm is in close contact with the upper surface 7a of the ring groove 7.

The lower oil ring 9b in the figure is rounded by the drag action of the cylinder wall 2, and the inclination of the lower oil ring 9b, as shown in FIG. 3, presses the leaf spring J2 upward. The upward force applied to the leaf spring 12 pushes the inclined surface 10m of the upper oil ring 9a. This inclined surface 10a
The force applied by the inclined surface JOa is in the outer radial direction
Branched in the direction and upward direction. The force C in the outer radial direction expands the diameter of the upper oil ring 9a, thereby increasing the surface pressure of the barrel face against the cylinder Ii2, and the force C in the outer radial direction causes the upper oil ring 9a to move the upper surface 11h of the upper oil ring 9a against the upper surface 7 of the groove 7. Closer contact with the

On the other hand, if the lower oil ring 9b is tilted as shown, the fluid tightness between the barrel face of the oil ring 9b and the cylinder wall 2 is likely to be broken, and the P position is likely to be scraped off by the lower oil ring 9b. The oil flows into the space 15 through between the tip surface of the lower oil ring 9b and the cylinder wall 2.
Since this space 15 that flows into the space J5 communicates with the relief hole 8 through the oil passage holes 16, the oil flowing into the space J5 quickly escapes through the oil passage holes 16 and the relief hole 8. Therefore, the oil pressure in the space 15 does not increase.

Since the pressure in the space 15 does not increase and (3) the pressure of the upper oil ring 9a against the cylinder wall 2 increases as described above, oil does not escape from the sliding surface of the upper oil ring 9a. .

The faster the piston 3 moves, the faster the oil ring 9*
, 9b increases, the force of the lower oil ring 9b pushing the leaf spring J2 also increases, and therefore the upper oil ring 9a is applied from the leaf spring 12 to expand its diameter. The force exerted by the body also increases, leading to an increase in blood pressure.

Therefore, the upper oil ring 9a will further prevent oil leakage.

When the piston 3 is moved in the direction opposite to the direction of arrow A, toward the top dead center of the tab, the upper oil ring 9a is tilted, and the plate 2 and the lower side are Lower oil ring 9 due to the screwing action due to the inclined surface of oil ring 9b.
Since the blood pressure against the cylinder wall 2 of b increases, oil leakage is prevented.

As mentioned above, during engine operation, the oil ring 9
The fact that the blood pressure of m + 9 b against the cylinder wall 2 increases automatically due to the wedge action means that there is no need to set a high surface pressure of the oil ring 9h + 9b against the cylinder wall 2 during assembly. , during assembly, the oil ring 9a.

9b and the leaf spring 12, and the oil ring 9m +
9b and the ring groove 7, it can be assembled with some wobbling as shown in FIG.

Therefore, assembly is extremely easy.

In addition, in the above embodiment, the oil rings 9&, 9b
Although the sloped surfaces 10m and 10b are provided on the plate spring 12, and the sloped surfaces 74m and J4b are also formed on the plate spring 12, the present invention is not limited thereto.For example, as shown in FIG. 4, the oil ring 9m is formed.

It is possible to provide the inclined surfaces 111)a, 10b only on the leaf spring 9b, or to provide the inclined surfaces 14m, 14b only on the leaf spring 12, as shown in FIG.

As described in detail above, according to the present invention, when the oil ring on the front side in the movement direction is dragged and displaced by the cylinder wall when the piston moves, this displacement is converted into a pressing force of the leaf spring, and the oil ring is Due to the inclined surface formed between the spring and the rear oil ring, a force for expanding the diameter of the rear oil ring can be generated to automatically increase the blood pressure against the cylinder wall. Therefore, no oil leaks from the sliding motion, and even if the oil in front of the front car oil ring leaks from the sliding surface of the front oil ring due to the displacement of the front oil ring, it will not leak from the leaf spring. Since the leakage is allowed to flow through the formed hole and the relief hole provided in the piston, an increase in the oil pressure in front of the rear oil ring is prevented, which also contributes to preventing oil leakage. In this way, since the surface pressure of the oil ring automatically increases while the Ennon is in operation, the oil ring assembly materials sometimes do not require a high preset pressure, making it easier to assemble the oil ring and assemble the piston. becomes easier.

[Brief explanation of drawings]

1 to 3 show an embodiment of the present invention (7, 1
The figure is a close-up view of the piston with a bleached cylinder, Figure 2 is an enlarged sectional view of the section in Figure 1, Figure 3 is an explanatory diagram of its operation, and Figures 4 and 5 are (relays). It is a sectional view showing the Q teardrop shape ψ of the present invention. 1... Cylinder, 2... Sleeve (cylinder 11)
, 3... Piston, 7... Oil ring groove, 8...
・Escape hole, 9 a a 9 b-Oil ring, J Oa
, J Ob -=slanted surface, 12... leaf spring, 24
a, J4b... Slanted surface, 16... Oil hole.

Claims (1)

[Claims] A pair of oil rings spaced apart from each other along the moving direction of the piston are fitted into a ring groove formed on the circumferential surface of the engine piston, and 64 springs are provided to push these oil rings toward the cylinder wall. In a structure in which an oil relief hole is provided in the bottom surface of the leaf spring and a through hole is formed in the leaf spring, at least 10,000 of the surfaces of the oil rings facing inward and the surface of the leaf spring that abuts the opposing surface of the oil ring The structure of the oil ring of an engine piston is similar to that of the oil ring in that a sloped surface is formed to absorb the surface pressure against the cylinder wall of the oil ring.