JPH09257130A - Piston ring of internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a piston ring for minifying an added load comparatively and not prograssing any wear, even if the entire upper surface of the piston ring is collided to the upper surface of a piston ring groove at a time. SOLUTION: An upper surface 10 of a piston ring is formed in nearly parallel with the upper surface 8 of a piston ring groove and the lower surface 11 of the piston ring is formed with an angle θso that the clearance between the lower surface 9 of the piston ring groove and it as it heads for from the inner periphery side 12 of the piston ring to its outer periphery side 13 is enlarged gradually. The angle θ is nearly equal to the angle θ (0<θ<1 deg.) made between the lower surface of the piston ring with an inner bevel and the lower surface of the piston ring groove.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to improvement of piston ring groove aggression of a piston ring.

[0002]

2. Description of the Related Art As a conventional piston ring for an internal combustion engine, for example, there is one shown in FIG. 5 (first conventional example). The piston ring 1 is fitted into a piston ring groove 5 provided in the piston 2 and inserted into the cylinder bore 7. Further, since the diameter of the piston ring 1 in the free shape is larger than the diameter of the cylinder bore, when inserted into the cylinder bore 7, a force to spread outward in the radial direction is generated, and the sliding surface 3 of the piston ring 1 and the inner surface 6 of the cylinder bore. A pressure is generated between them to seal the gas pressure in the combustion chamber and the oil in the crankcase. Further, FIG. 6 shows a second conventional example, in which the inner bevel 4 is provided at the inner peripheral side corner of the piston ring of FIG.
It has a chamfer called. By attaching the inner bevel 4 to the piston ring 1, the rigidity of the upper portion of the piston ring 1 becomes smaller than the rigidity of the lower portion thereof.
When it is inserted into the outer peripheral side, the outer peripheral side is warped so as to be higher than the inner peripheral side (FIG. 7). By taking such a shape, effects such as improvement of the ring posture and improvement of the sealing property are obtained.

[0003]

However, in such a conventional piston ring for an internal combustion engine, in the configuration without the inner bevel 4 (first conventional example), the ring groove upper and lower surfaces 8 and 9 and the piston ring upper and lower surfaces are formed. Both 10 and 11 are parallel, and in the configuration with the inner bevel 4 (second conventional example), the ring groove upper and lower surfaces 8 and 9 and the piston ring upper and lower surfaces 10 and 11 both have an angle. , In the first conventional technology without the inner bevel 4,
When the piston ring 1 is seated on the lower surface 9 of the piston ring groove under the combustion pressure, a large amount of load is applied to the lower surface 9 of the piston ring groove, which increases wear. However, when the piston ring 1 is seated on the upper surface 8 of the piston ring groove, combustion pressure or compression is applied. Since the force that presses the piston ring downward due to pressure works,
When the piston ring 1 is seated on the lower surface 9 of the piston ring groove under the combustion pressure, the load acting on the piston ring is reduced and wear is reduced. Since the piston ring groove lower surface 9 is gradually worn, the wear is small, but when the gas pressure is small, the ring is always urged so as to contact the piston ring groove upper surface outer side 14, so that it is directed from the radially inner side to the outer side. Therefore, there is a problem in that the wear is increased on the outer surface 14 of the upper surface of the piston ring groove.

The present invention has been made by paying attention to such a conventional problem, and a gap between the piston ring lower surface 11 and the piston ring groove lower surface 9 or the piston ring upper surface 10 and the piston ring groove upper surface 8 or both of them is formed. It is an object of the present invention to solve the above problems by providing a structure in which the piston ring lower surface 11 and / or the piston ring upper surface 10 are angled so that they gradually increase from the inner circumference to the outer circumference of the piston ring.

[0005]

In order to achieve the above object, in the invention according to claim 1, in a piston ring of an internal combustion engine which is mounted in a piston ring groove provided in the piston and is inserted into a cylinder, The angle between the upper surface of the ring and the upper surface of the piston ring groove is substantially parallel, and the angle between the lower surface of the piston ring and the lower surface of the piston ring groove gradually increases from the inner circumference to the outer circumference of the piston ring groove. It has a structure attached. Further, in the invention according to claim 2, as it goes from the inner circumference to the outer circumference of the piston ring groove according to claim 1,
The top surface of the piston ring is angled so that the gap between the top surface of the piston ring and the top surface of the piston ring groove gradually increases. Further, in the invention according to claim 3, an inner peripheral side section of the piston ring upper and lower surfaces is parallel to the piston ring groove upper and lower surfaces, and the section and the angled piston ring upper and lower surfaces are smoothly connected. did. Also,
According to the fourth aspect of the invention, the angle θ formed by the upper and lower surfaces of the piston ring according to the first to third aspects or the upper and lower surfaces of the piston ring groove attached to both sides is 0 <θ <1 °. In the invention according to claim 5, when the piston ring according to any one of claims 1 to 4 has a shape seated on the lower surface of the piston ring groove, the cylinder is formed in an arc portion below the arc center of the sliding surface of the piston ring. The sliding surface was processed so that it would come into contact with.

[0006]

According to the piston ring of the present invention, when the piston ring is seated on the upper surface of the piston ring groove, the entire upper surface of the piston ring collides with the upper surface of the piston ring groove at one time. Does not progress. Further, when the piston ring is seated on the lower surface of the piston ring groove, the piston ring receives cylinder pressure and collides with the lower surface of the piston ring groove with a relatively large force. Since the piston ring gradually contacts the outer peripheral side, wear of the lower surface of the piston ring groove is suppressed.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing a first embodiment of the present invention. First, the structure will be described. The piston ring upper surface 10 is formed substantially parallel to the piston ring groove upper surface 8, and the piston ring lower surface 11 has a gap between the piston ring groove lower surface 9 and the piston ring lower surface 9 from the inner peripheral side to the outer peripheral side. It is molded with an angle θ so as to gradually increase. Further, the angle θ is substantially the same as the angle θ (0 <θ <1 °) formed by the piston bevel lower surface 11 with the inner bevel and the piston ring groove lower surface 9 (see the conventional example in FIG. 7).

Next, the operation will be described. When the piston ring 1 is seated on the piston ring groove upper surface 8, according to the piston ring 1 of the present invention, the entire piston ring upper surface 10 collides with the piston ring groove upper surface 8 at one time, but the load applied is relatively small, so that the piston ring 1 wears so much. Does not progress. Further, when the piston ring 1 is seated on the lower surface 9 of the piston ring groove, the piston ring 1 receives the in-cylinder pressure and collides with the lower surface 9 of the piston ring groove with a relatively large force. Since the inner circumference side 12 gradually contacts the piston ring outer circumference side 13, wear of the piston ring groove lower surface 9 is suppressed.

FIG. 2 shows the second embodiment. In the second embodiment, the piston ring lower surface 11 is the same as in the first embodiment.
Is shaped so that the ring twist angle θ with the inner bevel is the same as the piston ring groove lower surface 9, and the piston ring upper surface 10 also moves from the piston ring inner peripheral portion 12 to the outer peripheral portion 13 as the piston ring groove upper surface increases. The angle φ is set so that the clearance with 8 becomes large. This angle φ is substantially equal to or smaller than the angle θ formed on the lower surface 11 of the piston ring (φ ≦ θ). According to this configuration, when seated on the lower surface 9 of the piston ring groove, it is the same as in Embodiment 1, but when seated on the upper surface 8 of the piston ring groove, the inner circumference of the piston ring is the same as when seated on the lower surface 9. Side 12 to piston ring outer circumference side 13
The wear of the upper surface 9 of the Biston ring groove is suppressed because the contact is gradually made toward. Further, by adopting this configuration (φ ≦ θ 2), it is possible to prevent the piston ring 1 from warping downward, and prevent deterioration of blow-by performance and oil consumption.

FIG. 3 shows a third embodiment. In the third embodiment, as in the second embodiment, when the piston ring upper and lower surfaces 10 and 11 are formed at angles θ and φ with respect to the piston ring groove upper and lower surfaces 8 and 9 (only the lower surface is shown in the figure), Instead of attaching from the contact point 16 with the surface 15,
In the vicinity of the inner peripheral surface 15 of the piston ring, they are substantially parallel to the upper and lower surfaces 8 and 9 of the piston ring groove, and the connecting portions with the angled surfaces θ and φ are smoothly connected. With this configuration,
When the piston ring 1 collides with the upper and lower surfaces 8 and 9 of the piston ring groove, the impact is reduced and the piston ring 1 is twisted smoothly.
Wear is suppressed.

FIG. 4 shows a fourth embodiment. In the fourth embodiment, when the piston ring 1 has a shape in which the piston ring lower surface 11 is pressed against the piston ring groove lower surface 9, the piston ring sliding surface 3 is the arc center of the piston ring sliding surface 3. The piston ring sliding surface 3 is machined so as to come into contact with the cylinder at the lower circular arc portion. As a method, it is conceivable to process the piston ring sliding surface 3 while applying an external force so that the piston ring lower surface 11 of the piston ring 1 has a shape when pressed against the piston ring groove lower surface 9. Oil consumption and blow-by performance are better when the piston ring sliding surface 3 faces upward than when it faces downward of the cylinder. Therefore, the piston ring sliding surface 3
If the above-mentioned sliding surface is taken when is oriented downward, the sliding surface will not face downward, and oil consumption and blow-by performance will be good.

As described above, according to these embodiments, the structure is configured by the piston ring lower surface 11 and the piston ring groove lower surface 9 or the piston ring upper surface 10.
And the gap between the piston ring groove top surface 8 or both,
Since the piston ring lower surface 11 and / or the piston ring upper surface 10 or both are provided with angles θ and φ so as to gradually increase from the inner circumference of the piston ring to the outer circumference, the piston ring upper surface 10 outer peripheral side is the piston ring groove upper surface outer side 14 The wear of the piston ring groove upper surface 8 which increases from the inner peripheral side to the outer peripheral side is suppressed, and the piston ring lower surface 11 gradually moves from the inner peripheral side to the outer peripheral side in the piston ring groove lower surface 9. Since the piston ring 1 and the lower surface 9 of the piston ring groove can be softened, the abrasion of the lower surface 9 of the piston ring groove can be suppressed. Further, each embodiment has the following effects in addition to the common effects described above. Embodiment 2
Even when the piston ring 1 is seated on the piston ring groove upper surface 8, the piston ring 1 gradually contacts from the inner peripheral side to the outer peripheral side, and wear of the piston ring groove upper surface 8 can be further suppressed. In the third embodiment, the impact when the inner peripheral side of the piston ring 1 comes into contact with the piston ring groove upper and lower surfaces 8 and 9 can be softened and the twist of the piston ring 1 can be smoothed, so that the piston ring groove upper surface 8 is worn. Can be further suppressed. In the fourth embodiment, the piston ring sliding surface 3 does not face the lower side of the cylinder, and it is possible to prevent deterioration of oil consumption characteristics, probe-by performance, and the like.

Although the preferred embodiment of the present invention has been described in detail with reference to the drawings, the specific configuration is not limited to this preferred embodiment, and a design change or the like may be made without departing from the gist of the present invention. If so, they are included in the present invention.

[0014]

As described above, according to the present invention, the structure is such that the clearance between the piston ring lower surface and the piston ring groove lower surface, the piston ring upper surface and the piston ring groove upper surface, or both of them is from the inner circumference of the piston ring. Since the piston ring lower surface, the piston ring upper surface, or both are angled so that they gradually increase toward the outer circumference, the piston ring upper surface outer peripheral side does not attack the piston ring groove upper surface outer side and the piston ring groove upper surface inner peripheral Side is suppressed from increasing to the outer peripheral side, and the lower surface of the piston ring is gradually seated on the lower surface of the piston ring groove from the inner peripheral side to the outer peripheral side. Can be softened and suppresses wear on the bottom surface of the piston ring groove The effect that it can be obtained is obtained.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a first embodiment of the present invention.

FIG. 2 is a sectional view showing a second embodiment of the present invention.

FIG. 3 is a sectional view showing a third embodiment of the present invention.

FIG. 4 is a sectional view showing a fourth embodiment of the present invention.

FIG. 5 is a sectional view showing a conventional example without an inner bevel 4.

FIG. 6 is a cross-sectional view showing a conventional example with an inner bevel 4.

FIG. 7 is a sectional view exaggeratingly showing the effect of the inner bevel 4.

[Explanation of symbols]

 1 Piston ring 2 Piston 3 Piston ring sliding surface 4 Inner bevel 5 Piston ring groove 6 Cylinder bore inner surface 7 Cylinder bore 8 Piston ring groove upper surface 9 Piston ring groove lower surface 10 Piston ring upper surface 11 Piston ring lower surface 12 Piston ring inner peripheral side 13 Piston ring outer circumference Side 14 Piston ring groove upper surface outer peripheral side 15 Piston ring inner peripheral surface 16 Piston ring inner peripheral surface and lower surface contact point

Claims (5)

[Claims] 1. A piston ring for an internal combustion engine, which is mounted in a piston ring groove provided in a piston and inserted into a cylinder, wherein an angle formed between the upper surface of the piston ring and the upper surface of the piston ring groove is substantially parallel to each other. A piston ring for an internal combustion engine, wherein the lower surface of the piston ring is angled so that the clearance between the lower surface of the piston ring and the lower surface of the piston ring groove gradually increases from the circumference to the outer circumference. 2. The piston ring upper surface is angled so that the clearance between the piston ring upper surface and the piston ring groove upper surface gradually increases from the inner circumference to the outer circumference of the piston ring groove. A piston ring for an internal combustion engine as described. 3. The piston ring upper and lower surfaces in the vicinity of the inner peripheral side are parallel to the piston ring groove upper and lower surfaces, and the section and the angled piston ring upper and lower surfaces are smoothly connected. Alternatively, the piston ring of the internal combustion engine according to claim 2. 4. An angle θ formed between the upper and lower surfaces of the piston ring or the upper and lower surfaces of the piston ring groove attached to both surfaces.
The piston ring of the internal combustion engine according to any one of claims 1 to 3, wherein is set to 0 <θ <1 °. 5. When the piston ring is seated on the lower surface of the piston ring groove, the sliding surface is machined so that it contacts the cylinder at an arc portion below the arc center of the piston ring sliding surface. 5. The method according to claim 1, wherein
A piston ring for an internal combustion engine as described in 1.