JPH06265020A - Compression ring for internal combustion engine - Google Patents

Abstract

PURPOSE:To reconcile security of high surface pressure to a cylinder inner wall and maintenance of a proper contact angle in a compression ring for an internal combustion engine to carry out a gas seal and an oil seal between a piston and a cylinder. CONSTITUTION:A spring 12 to exhibit prescribed tensile force in the outer peripheral direction is arranged on the inner periphery of a compression ring 10 installed on the outer periphery of a piston so as to secure sealing performeance with a cylinder inner wall 16. An outer peripheral surface 13 of the compression ring 10 is composed of a taper surface 13a, a slidably movable surface 13b and a projecting part 13c. Both the slidably movable surface 13b and the projecting part 13c are set in the same height, and are formed mutually in an offset part on the opposite side while sandwiching the axis of the tensile force by a spring 12 between them.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a compression ring for an internal combustion engine, and more particularly to a compression ring for an internal combustion engine which is installed on the outer circumference of a piston to perform a gas seal and an oil seal between the piston and the cylinder.

[0002]

2. Description of the Related Art Conventionally, in a reciprocating internal combustion engine, a compression ring is used to secure a gas seal, an oil seal, etc. between a piston and an inner wall of a cylinder. This is because if the gas seal between the cylinder inner wall and the piston is poor, the desired combustion pressure cannot be obtained, and if the oil seal is insufficient, an unreasonably large amount of lubricating oil is consumed.

FIG. 4 is a perspective view of a piston 1 for showing the arrangement structure of a compression ring generally adopted in an internal combustion engine mounted on a vehicle. As shown in the figure, in a vehicle-mounted internal combustion engine, a configuration in which three compression rings are installed on the outer circumference of a piston is generally adopted.

These three compression rings are
The top ring 3, the second ring 4, and the oil control ring 5 are called in order from the combustion chamber 2 side (upper side in FIG. 4), and each slidably contacts the cylinder inner wall 6 of the internal combustion engine to exert its own effect. There is.

For example, a compression ring combustion chamber 2
The highest pressure is naturally applied to the top ring 3 installed on the side. The top ring 3 is required to effectively block the high combustion pressure to secure a good gas seal.

In this case, if the gas sealability is insufficient, the combustion pressure generated in the combustion chamber 2 cannot be efficiently converted into mechanical energy via the piston 1,
The gas sealability of the top ring 3 is one of the important factors that determine the characteristics of the internal combustion engine because it has a great influence on the fuel consumption and output characteristics of the internal combustion engine.

On the other hand, the pressure in the combustion chamber 2 is not so much propagated to the oil control ring 5 installed at the position farthest from the combustion chamber 2. This is because the combustion pressure is doubled by the top ring 3 and the second ring 4. That is, the oil control ring 5 is provided not for ensuring the gas sealability but for ensuring the good oil sealability.

This oil sealing property is required to prevent the lubricating oil used for smoothing the sliding between the piston 1 and the cylinder inner wall 6 from unduly flowing into the combustion chamber 2. It is something. Therefore, when the oil sealability is not sufficiently ensured, a large amount of lubricating oil flows into the combustion chamber 2, a large amount of oil is consumed, and the exhaust emission deteriorates. Like the sealability, it is an important factor in the characteristics of the internal combustion engine.

A second ring 4 located between the top ring 3 and the oil control ring 5 is provided to assist the functions of these rings 3 and 5, and the function thereof is a gas seal. And oil sealability are both required.

As described above, the compression rings incorporated in the piston 1 are required to have different functions. For this reason, each ring has been devised in its configuration so that it can effectively exhibit its required functions. For example, the top ring 3 is configured to ensure a high surface pressure. Further, in the case of the oil control ring 5, the cross section of the oil control ring 5 has a wedge shape that faces the lower side of the piston 1 to improve the oil scraping effect.

FIG. 5 (A) shows a second ring 4 which is required to exhibit the effects of gas sealability and oil sealability.
FIG. 3 is a cross-sectional view showing the structure of the main part of the ring disclosed in the publication.

In FIG. 5 (A), a ring shape is provided on the inner peripheral side of the second ring 4 so as to apply tension toward the outer peripheral direction of the second ring 4, that is, in the direction of increasing the outer diameter of the second ring 4 when it is free. The spring 7 is provided. Therefore, when the piston 1 including the ring 4 is incorporated in the cylinder, the second ring 4 comes into contact with the cylinder inner wall 6 with a high surface pressure applied by the spring 7, and a good gas sealing property is secured.

As shown in FIG. 5A, the outer peripheral surface 8 of the second ring 4 is on the combustion chamber 2 side (upper side in the figure).
And a sliding surface 8b formed on the opposite side (lower side in the figure) of the combustion chamber 2 and having an edge. Therefore, when the piston 1 moves from the bottom dead center to the top dead center, the sliding surface 8b positively rides on the oil film formed on the cylinder inner wall 6, and conversely the piston moves downward from the top dead center. When moving toward the dead point, the oil film is scraped off by the edge formed at the end of the sliding surface 8b, so that the oil film is formed to have an appropriate thickness.

[0014]

However, in the conventional second ring 4 described above, the tension W of the spring 7 causes a predetermined moment M to the outer peripheral surface 8 as shown in FIG. 5B. To work. Spring 7
The x-axis, which is the axis of the tension, and the outer peripheral surface 8 are the cylinder inner wall 6
This is because the y-axis, which is the axis of the reaction force received from, is offset.

Therefore, when the shape of the above-mentioned conventional second ring 4 at the time of assembling is accurately represented, it is actually as shown in FIG.
As shown in (C), the ring 4 itself is twisted. Since this strain is generated due to the moment M, it is generated with the boundary between the tapered surface 8a and the sliding surface 8b of the ring 4 as a fulcrum.

As a result, the cylinder inner wall 6 of the tapered surface 8a
The angle with respect to is smaller than the desired angle originally designed at θ3. On the other hand, an angle of θ2 is formed between the sliding surface 8b capable of exhibiting the edge effect by making surface contact with the cylinder inner wall 6 and the cylinder inner wall 6, and the effect of scraping off the lubricating oil by the edge is sufficiently exerted. It will not be possible.

On the other hand, when the x-axis which is the axis of the tension W of the spring 7 and the y-axis which is the axis of the reaction force from the cylinder inner wall 6 are made to coincide with each other at the initial design, the moment M is applied in the initial stage. It does not occur, and the intended effect can be obtained by forming a predetermined ring shape. However, even when such a structure is adopted, if the ring 4 is worn by sliding, the above-mentioned y-axis may deviate from the x-axis, resulting in a similar situation.

As described above, in the conventional compression ring described above, even if the outer peripheral surface of the ring is formed into a shape capable of exerting a predetermined effect, the tension applied to secure the surface pressure between the compression ring and the inner wall of the cylinder. There is a problem in that the effect cannot be sufficiently exhibited due to the twist caused by.

The present invention has been made in view of the above points, and a protrusion having the same height as the sliding surface is provided on the side opposite to the sliding surface with respect to the axis of the applied tension, and the ring outer circumference is provided. An object of the present invention is to provide a compression ring for an internal combustion engine that can solve the above problems by preventing surface distortion.

[0020]

The above object is to provide a compression ring for an internal combustion engine equipped with a tension applying means for applying a predetermined tension from the inner peripheral surface side toward the outer peripheral surface direction, the compression ring being attached to the outer peripheral surface of the piston of the internal combustion engine. The sliding surface having a predetermined shape formed on the outer peripheral surface at a position offset from the axis of tension by the tension applying means, and the sliding surface with respect to the axis of tension by the tension applying means. This is achieved by a compression ring of an internal combustion engine that includes a convex portion that is formed on a portion on the outer peripheral surface that is offset to the side opposite to the surface, and that has a height that is equal to the sliding surface.

[0021]

When the compression ring of the internal combustion engine according to the present invention is mounted on the piston of the internal combustion engine and incorporated in the cylinder, the outer peripheral surface of the compression ring is urged toward the inner wall of the cylinder by the action of the tension applying means. It At this time, the sliding surface and the convex portion formed on the outer peripheral surface,
Both of them come into contact with the inner wall of the cylinder and receive a reaction force against the biasing force of the tension applying means.

In this case, the reaction forces received by the sliding surface and the convex portion are offset from each other with respect to the axis of the tension generated by the tension applying means.
Therefore, no moment that causes distortion is generated on the outer peripheral surface, and the sliding surface contacts the inner wall of the cylinder with a desired contact angle. Therefore, the effect due to the predetermined shape of the contact surface is always ensured, and high performance as a compression ring is exhibited.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1A is an enlarged cross-sectional view showing the structure of the essential part of an embodiment of a compression ring for an internal combustion engine according to the present invention. The compression ring 10 shown in FIG.
Is configured as a second ring mounted on the outer circumference of the piston of the internal combustion engine, and is intended to secure high gas sealability and high oil sealability.

On the inner circumference of the compression ring 10,
An inner groove 11 having a predetermined width is provided over the entire circumference. A spring 12 wound into a diameter d that can be accommodated in the groove is incorporated in the inner groove 11. By the way, the spring 12 is a ring-shaped spring having a diameter larger than the inner diameter of the compression ring 11 when it is left without any external force.

Therefore, in order to assemble the spring 12 into the inner groove 11 of the compression ring 11 as shown in FIG. 1 (A), it is necessary to forcibly contract the spring 12 and once reduce its diameter to fit it. . When fitted in this way, the restoring force of the spring 12 acts in the direction of increasing its diameter, so that the compression ring 10 is in a state in which tension is applied from the inner peripheral side toward the outer peripheral direction. That is, the spring 12 in this embodiment corresponds to the tension applying means described above.

The outer peripheral surface 13 of the compression ring 10 has a taper surface 13a, a sliding surface 13b and a convex portion 1.
3c is provided. Here, when the compression ring 10 is incorporated into a piston of an internal combustion engine, the tapered surface 13a has a small diameter on the side close to the combustion chamber (upper side in FIG. 1A) and the opposite side (FIG. 1A). ), The lower side) is a surface having an inclination such that the diameter becomes large.

The sliding surface 13b is a surface which is continuously provided from the lower end of the tapered surface 13a and is formed in a ring shape over the entire circumference of the compression ring 10. This side is
It is a portion that slides in a state of surface contact with the inner wall of the cylinder when the compression ring 10 is arranged in the cylinder of the internal combustion engine.

The convex portion 13c is a continuous or discontinuous protrusion provided on the upper end of the tapered surface 13a, and is appropriately arranged in a ring shape or discretely over the entire outer peripheral surface 13. Has been done. The height of the convex portion 13c is set so that its apex is the same as the height of the sliding surface 13b. Therefore, the compression ring 10
When the cylinder is arranged in the cylinder, the convex portion 13c also comes into contact with the inner wall of the cylinder similarly to the sliding surface 13a.

By the way, FIG. 1B is an enlarged cross-sectional view showing a state in which the compression ring 10 having such a structure is arranged in the cylinder of the internal combustion engine. As described above, the compression ring 10 of this embodiment is tensioned by the spring 12.

For this reason, in the conventional compression ring which is not provided with the tension applying means such as the spring 10, the surface pressure with the cylinder inner wall 16 can be secured only at about ² kgf / cm ² , whereas in the present embodiment. According to the compression ring 10 of the example, the surface pressure can be increased to about 6 kgf / cm ² , for example. Therefore, when the ring 10 of the present embodiment is used as the second ring, the gas sealability is remarkably improved as compared with the conventional second ring, and the fuel efficiency and output characteristics of the internal combustion engine can be improved.

On the other hand, when used as a second ring, a high oil sealing effect is also required. Therefore, in the compression ring 10 of the present embodiment, a known outer peripheral surface shape is adopted as a configuration that can easily secure such an effect, and the tapered surface 13a and the sliding surface 13b are formed. This is because in order for the piston to smoothly slide in the cylinder of the internal combustion engine, it is necessary to form a lubricating oil film having an appropriate thickness between the cylinder inner wall 16 and the compression ring 10.

That is, the lubricating oil in the internal combustion engine is stored in the lower portion of the piston, and when the piston is located near the top dead center, a large amount of lubricating oil adheres to the cylinder inner wall 16 in the lower portion of the compression ring. To do. Therefore, in order to prevent an unduly large amount of lubricating oil from flowing into the combustion chamber, it is necessary to appropriately scrape off the lubricating oil attached to the cylinder inner wall 16 when the piston moves toward the bottom dead center. is there.

Further, when the piston moves from the bottom dead center to the top dead center, an oil film of an appropriate thickness formed on the cylinder inner wall 16 at that time is effectively used as a lubricant to make the sliding surface 13b. And the cylinder inner wall 16 must be involved. This is because it is necessary to secure the lubrication effect and reduce the amount of the lubricating oil existing on the combustion chamber side when reaching the vicinity of the top dead center.

In this case, in the structure in which the outer peripheral surface of the compression ring 10 is provided with the tapered surface 13a and the lubricating surface 13b, when the piston moves toward the top dead center, the tapered surface 13a is appropriately lubricated. When the oil is caught and the piston moves from the top dead center to the bottom dead center, the oil film is appropriately scraped off by the edge effect of the end portion of the lubricating surface 13b.

However, when the outer circumference of the compression ring 10 is composed of only the tapered surface 13a and the lubricating surface 13b, the outer peripheral surface 13 is caused by the tension W of the spring 12.
Is distorted, and it becomes impossible to maintain an appropriate contact angle between the tapered surface 13a and the sliding surface 13b. Therefore, under such a situation, the oil film control of the lubricating oil formed on the cylinder inner wall 16 may not be properly executed.

The convex portion 13c of the compression ring 10 of this embodiment is configured to receive the tension W of the spring 12 at two points, and is provided to prevent the distortion of the outer peripheral surface 13. That is, as shown in FIG. 1B, the tension W generated in the spring 12 is
The reaction force F _{1 at} 3b and the reaction force F _{2 at the} convex portion 13c are balanced.

Therefore, the contact angle of the tapered surface 13a and the sliding surface 13b of the compression ring 10 with respect to the cylinder inner wall 16 is always maintained at an appropriate angle, and the effect originally intended to be exhibited based on those shapes. Always demonstrated. Therefore, when the compression ring 10 of this embodiment is used as the second ring, both the gas sealability and the oil sealability are remarkably improved as compared with the case where the conventional second ring is used.

In the compression ring 10 shown in FIG. 1, the convex portion 13c has a semicircular cross section. This is to reduce the influence of the convex portion 13c on the lubricating oil film formed on the cylinder inner wall 16. In this case, when the convex portion 13b is formed as a discontinuous projection, its influence is further reduced, and the oil film entrainment effect of the tapered surface 13a and the sliding surface 1
The oil film scraping effect of 3b is exhibited almost in the same manner as when the convex portion 13c does not exist.

FIG. 2 is an enlarged cross-sectional view showing the structure of the essential part of a second embodiment of the compression ring for an internal combustion engine according to the present invention. In the figure, the same components as those in FIG. 1 are designated by the same reference numerals and the description thereof will be omitted.

The compression ring 20 of this embodiment
Is characterized in that it has a recess 21 at the bottom of the sliding surface 13. The other configurations are the same as those of the compression ring 10 in the above embodiment except that the width occupied by the tapered surface 22 is narrowed due to the recess 21.

In this case, the recess 21 is provided to improve the ability to scrape off the lubricating oil, and the tension exerted by the spring 12 is more directly exerted on the sliding surface 13.
Since the lubricating oil scraped off is stored in the recessed portion while being transmitted to b, the lubricating oil scraping effect when the piston moves toward the bottom dead center is enhanced. In this embodiment also, the tension W of the spring 12 is
Since the sliding surface 13b and the convex portion 13c are offset to the opposite side with respect to the axis of, the compression ring 20 is not distorted due to the tension W.

FIG. 3 is an enlarged cross-sectional view showing the structure of the essential parts of a third embodiment of the compression ring for an internal combustion engine according to this embodiment. The compression ring 30 shown in FIG.
Has a characteristic in the cross-sectional shape of the convex portion 31, and except for the characteristic portion, the compression ring 1 of the first embodiment described above.
It has the same configuration as 0.

The compression ring 30 of this embodiment
Has a tapered surface 31a and a sliding surface 31b having an edge in the convex portion 31. Therefore, when the piston moves up or down, the tapered surface 13a is provided to exert the effect of entraining the lubricating oil and the effect of scraping the lubricating oil.
Also, the projection 31 itself as well as the sliding surface 13b exerts an effect of being caught and scraped off. Therefore, sliding between the convex portion 31 and the cylinder inner wall 14 becomes smooth, and the film pressure accuracy of the lubricating oil film formed on the cylinder inner wall is improved.

[0044]

As described above, according to the present invention, the convex portion provided on the outer peripheral surface of the compression ring can prevent the strain caused by the tension applied by the tension applying means. Therefore, the outer peripheral surface of the compression ring has a high surface pressure against the cylinder inner wall of the internal combustion engine,
In addition, it is possible to always slide while maintaining an appropriate contact angle.

As described above, according to the compression ring of the internal combustion engine of the present invention, unlike the conventional compression ring, it is possible to achieve both a high surface pressure and an appropriate contact angle at which the original function can be exhibited. . Therefore, by installing the compression ring according to the present invention, the gas sealability and oil sealability of the internal combustion engine can be remarkably improved, and its output characteristics and oil consumption can be easily reduced. It has the feature that it can be realized.

[Brief description of drawings]

FIG. 1 is an enlarged cross-sectional view showing a configuration of a main part of an embodiment of a compression ring of an internal combustion engine according to the present invention.

FIG. 2 is an enlarged cross-sectional view showing a configuration of a main part of a second embodiment of a compression ring for an internal combustion engine according to the present invention.

FIG. 3 is an enlarged cross-sectional view showing a configuration of a main part of a third embodiment of a compression ring for an internal combustion engine according to the present invention.

FIG. 4 is a perspective view of a piston equipped with a compression ring.

FIG. 5 is an enlarged cross-sectional view showing a configuration of a main part of a conventional compression ring.

[Explanation of symbols]

 10, 20, 30 Compression ring 11 Inner groove 12 Spring 13 Outer peripheral surface 13a, 22, 31a Tapered surface 13b, 31b Sliding surface 13c, 31 Convex portion 16 Cylinder inner wall

Claims (1)

[Claims] 1. A compression ring of an internal combustion engine, comprising a tension applying means for applying a predetermined tension from an inner peripheral surface side to an outer peripheral surface direction, the compression ring of the internal combustion engine being mounted on an outer peripheral surface of a piston of the internal combustion engine. A sliding surface of a predetermined shape formed in a portion offset from the axis of tension by the tension applying means, and an offset on the side opposite to the sliding surface with respect to the axis of tension by the tension applying means A compression ring for an internal combustion engine, comprising: a protrusion formed on a portion on an outer peripheral surface and having a height equivalent to that of the sliding surface.