JP2000337509A - Combination piston ring device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a combination piston ring device that is appropriate as a pressure piston ring. SOLUTION: A taper-faced ring 9 and a spring seal ring 6 are disposed in mutually superposed fashion. The spring seal ring 6 has a cross section twisted like a disk spring, and the spring action presses, in a sealing relation, an upper internal portion 6a against a ceiling surface 3a of a piston ring groove 3 and a lower external portion 6b against a top surface 9b of the taper-faced ring 9. A small-diameter or upper piston-ring-groove end 3b for accommodating the spring seal ring 6 has a horizontal bottom surface 3f, and an axial breadth virtually equal to the axial breadth of the spring seal ring 6. Even if gas pressure acts on or tries to depress the spring seal ring 6, an external edge 3c of the bottom surface 3f of the upper piston-ring-groove end 3d is in overall contact with the spring seal ring 6 in a sealing relation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a combined piston ring device used as a pressure piston ring suitable for a reciprocating piston, particularly a piston of an internal combustion engine.

[0002]

2. Description of the Related Art As a conventional combination piston ring device, for example, an oil ring shown in FIG. 14 is known (see Japanese Utility Model Laid-Open No. 1-149549).

In the drawing, reference numeral 51 denotes a cylinder, 52 denotes a piston, and 53 denotes a piston ring groove. A seal ring 55 is disposed on a tapered cross-section ring 59, and a spring seal twisted in a disc spring shape is further provided thereon. A ring 56 is arranged. By the spring action of the spring seal ring 56 in the form of a disc spring, the inner peripheral upper surface side portion 56a presses against the upper surface 53a of the piston ring groove 53, and the outer peripheral lower surface side portion 56b presses against the seal ring 55 upper surface. Further, since the oil ring device is used, an oil return hole 54 is formed to penetrate along the lower surface 53b of the piston ring groove 53.

FIG. 15 shows an example of a conventional combined piston ring device configured as a pressure piston ring (Japanese Utility Model Laid-Open No. 58-178441). This is composed of a front ring 57 located on the outer peripheral side and a rear ring 58 located on the inner peripheral side, and both rings 57, 58 are respectively chamfered portions 57a, 58.
a and the front ring 57
Is provided on the upper surface 53a of the piston ring groove 53,
8 are pressed against the lower surface 53b of the piston ring groove 53, respectively.

[0005]

The former combined oil ring has a disadvantage that the number of rings sliding on the wall surface of the cylinder 51 is large and friction is increased. Further, when a gas pressure acts between the cylinder 51 and the piston 52 as indicated by an arrow A, a moment as indicated by an arrow B is generated in the spring seal ring 56, and a gap between the inner circumference of the spring seal ring 56 is generated. Gas flows to the oil return hole 54 through the gap 61 on the inner circumference of the ring 61 and the ring 59 of the tapered cross section.

On the other hand, in the latter combination piston ring device, as shown in FIG. 15A, during actual operation, the piston 52 tilts sharply, and the height of the combination of the front ring 57 and the rear ring 58 increases with time. When the gas pressure cannot be followed, the gas pressure indicated by the arrow A easily enters along the upper surface 53a of the piston ring groove 53, and the front ring 57
Press down further. Then, as shown in (b), the gas blows through at the timing when a gap is formed in the lower surface 53b of the piston ring groove 53.

Accordingly, an object of the present invention is to provide a combined piston ring device suitable as a pressure piston ring.

[0008]

The invention according to claim 1 is
A combined piston ring device housed in a piston ring groove formed in a piston and serving as a pressure piston ring having an abutment portion, wherein the piston ring device is disposed on a lower surface side of the piston ring groove, and a tapered outer peripheral surface is a cylinder wall surface. And a tapered cross-sectional ring that slides on the upper surface side of the piston ring groove, and the inner peripheral upper surface is on the upper surface of the piston ring groove, and the outer peripheral lower surface is on the tapered cross-sectional ring.
A spring seal ring having a cross-sectional shape twisted in the shape of a disc spring so as to be pressed against each other, wherein the spring seal ring presses the tapered cross-sectional ring toward the lower surface side of the piston ring groove.

According to a second aspect of the present invention, the lower part of the piston ring groove in which the tapered cross-section ring is housed is provided on the bottom surface of the piston ring groove. Are formed, and a piston ring groove bottom upper step smaller than the piston ring groove bottom lower step is formed, and the lower surface of the piston ring groove bottom upper step is formed by a difference in diameter between the two. I have.

Further, in the invention of claim 3, the axial width of the spring seal ring is set substantially equal to the axial width of the piston ring groove bottom upper step.

In the combined piston ring device provided with the spring seal ring as described above, the outer periphery of the spring seal ring is brought into pressure contact with the upper surface of the tapered cross-section ring by the spring action of the conical spring of the spring seal ring, and The inner circumference of the spring seal ring is pressed against the upper surface of the piston ring groove over the entire circumference.

Further, when a step is provided between the lower part of the piston ring groove bottom and the upper part of the piston ring groove bottom as in claim 2, even if the spring seal ring is pushed down by gas pressure, The spring seal ring abuts on the lower surface of the upper portion of the piston ring groove bottom between the two, and the seal is surely sealed here.

[0013] In particular, if it is configured as in claim 3,
The amount of leakage due to the movement of the spring seal ring is extremely small.

According to the fourth aspect of the present invention, the lower surface of the piston ring groove bottom upper portion forms a dish-shaped inclined surface corresponding to the torsion angle of the cross section of the spring seal ring. As a result, the spring seal ring comes into surface contact, which is advantageous in abrasion resistance and seizure resistance.

According to the fifth aspect of the present invention, when the piston is mounted, the spring seal ring has no gap at the abutment portion and between the inner peripheral surface and the piston ring groove bottom surface and between the outer peripheral surface and the cylinder wall surface. Are provided with gaps.

Thus, leakage from the joint is reduced, and the joint does not open even during thermal expansion.

Further, in the invention of claim 6, in the spring seal ring, an inner peripheral upper surface portion in contact with the upper surface of the piston ring groove and an outer peripheral lower surface portion in contact with the tapered cross-section ring are respectively parallel to the piston ring groove upper surface. Has a flat surface.

As a result, the spring seal ring comes into surface contact, which is advantageous in abrasion resistance and seizure resistance.

In the invention according to claim 7, the spring seal ring has an inner peripheral upper surface portion in contact with the upper surface of the piston ring groove, and an outer peripheral lower surface portion in contact with the tapered cross-section ring, the upper surface and the taper of the piston ring groove, respectively. It has a gentle curved surface circumscribing the upper surface of the sectional ring.

Even when the piston is tilted during operation and its relative attitude with respect to the piston ring changes, the contact portion of the spring seal ring seals reliably while moving the contact position according to the relative behavior. Thereby, the sealing property and the wear resistance are simultaneously secured.

In the combined piston ring device of the present invention, at least one abutment surface of the spring seal ring is formed as a substantially U-shaped seal surface which opens downward. Thereby, the sealing surface pressure at the abutment surface is increased, and the sealing performance is improved.

Further, in the ninth aspect of the present invention, a concave portion is formed on one of the abutting surfaces, and a convex portion is formed on the other. Thereby, the displacement of the abutment portion is prevented.

According to a tenth aspect of the present invention, the outer surface of the spring seal ring is coated with a resin. As this coating, a material having self-lubricating properties and abrasion resistance is desirable. As a result, the seal life is improved while maintaining the initial conformability.

In the combined piston ring device according to the eleventh aspect, a chamfered portion is provided on an inner peripheral upper surface portion of the tapered cross-sectional ring so as to compensate a downward pressing force by the spring seal ring.

That is, when the chamfered portion is formed on the inner peripheral upper surface of the tapered cross-section ring, the tapered cross-section ring is twisted such that the outer periphery thereof rises upward when mounted. Thereby, the spring seal ring comes into pressure contact with the outer peripheral lower surface side portion more strongly, and the sealing performance at this portion is improved.

According to a twelfth aspect of the present invention, in the eleventh aspect, the joint portion of the ring having the tapered cross section has a double stepped shape. By doing so, oil consumption due to the lubricating oil being brought into the combustion chamber is suppressed, and the amount of gas leakage is reduced.

[0027]

According to the combined piston ring device of the present invention, the outer periphery of the spring seal ring is pressed against the entire upper surface of the tapered cross-section ring by the spring action of the conical spring of the spring seal ring, and the piston ring is pressed. The inner periphery of the spring seal ring is pressed into contact with the upper surface of the groove over the entire periphery, and good sealing properties are obtained.

According to the second and third aspects of the present invention, when the spring seal ring is pressed down by the gas pressure, the spring seal ring abuts on the lower surface of the upper step portion of the piston ring groove bottom and is reliably sealed. Therefore, the amount of gas leakage is reduced.

According to the fourth and sixth aspects of the present invention, the abrasion resistance and the seizure resistance are improved by the surface contact.

According to the fifth aspect of the present invention, leakage from the abutment portion of the spring seal ring is reduced, and the sealing performance is further improved.

According to the seventh aspect of the present invention, even when the piston is tilted during operation and its relative attitude with respect to the piston ring changes, the sealing performance and the wear resistance are simultaneously secured.

According to the eighth and ninth aspects of the present invention, the sealing surface pressure at the abutment surface of the spring seal ring is increased, and the sealing performance is improved.

According to the tenth aspect of the present invention, the initial life of the spring seal ring is secured while the seal life is improved.

According to the combined piston ring device of the eleventh aspect, the outer peripheral portion of the tapered cross-section ring and the outer peripheral lower surface portion of the spring seal ring are more strongly pressed against each other, and the sealing performance at this portion is improved. I do.

According to the twelfth aspect of the present invention, oil consumption is suppressed and the amount of gas leakage is further reduced.

[0036]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 shows a first embodiment of the combined piston ring device according to the present invention. In the figure,
1 is a cylinder, 2 is a piston, and 3 is a piston ring groove. A tapered section ring 9 is disposed on the lower surface 3b side of the piston ring groove 3, and a spring seal is provided on the tapered section ring 9, that is, on the combustion chamber side. A ring 6 is arranged.
The tapered cross-section ring 9 has a tapered surface 9 a on the outer periphery, and the tapered surface 9 a slides on the wall surface 1 a of the cylinder 1. The spring seal ring 6 has an inner peripheral upper surface portion 6a on the upper surface 3a of the piston ring groove 3 and an outer peripheral lower surface portion 6b.
Have a sectional shape twisted in the shape of a disc spring so as to be pressed against the upper surface 9b of the tapered sectional ring 9, respectively.

In the bottom surface of the piston ring groove 3, a lower portion 3e of the piston ring groove bottom in which the tapered section ring 9 is accommodated, and the lower portion of the piston ring groove in which the spring seal ring 6 is accommodated. A lower portion 3d of the piston ring groove bottom upper step 3d having a diameter smaller than that of the piston ring groove bottom 3d is formed. ). In other words, the piston ring groove bottom lower step 3e and the piston ring groove bottom upper step 3
and d are formed in steps.

The piston ring groove bottom upper step 3
The axial width d is set substantially equal to the axial width of the spring seal ring 6, and the gap between the two is substantially zero. On the other hand, the axial width of the lower portion 3 e of the piston ring groove bottom is slightly larger than the axial width of the tapered section ring 9.

When the spring seal ring 6 is in a free state, as shown in FIG.
In the piston mounted state, the diameters are larger than in the free state, and the abutment surfaces 10a, 10b are in pressure contact with each other, as shown in FIG. Therefore, there is no gap in the joint 10. In this mounting state, as shown in FIG. 1, a gap 11 is formed between the inner peripheral surface and the bottom surface of the upper portion 3d of the piston ring groove bottom.
However, a gap 13 between the outer peripheral surface and the cylinder 1 wall surface 1a is
Each is secured.

In the combined piston ring device provided with the spring seal ring 6 as described above, the outer peripheral lower surface side portion of the spring seal ring 6 is formed on the upper surface 9b of the tapered cross-section ring 9 by the conical spring-like spring action of the spring seal ring 6. 6b is pressed against the entire circumference, and the inner peripheral upper surface side portion 6a of the spring seal ring 6 is pressed against the upper surface 3a of the piston ring groove 3 over the entire circumference. Further, as described above, there is no gap at the abutment portion 10 of the spring seal ring 6. Therefore, the combustion gas can be reliably sealed. Then, even when the gas pressure acts to push down the spring seal ring 6 as shown by the arrow A, the outer peripheral edge 3c of the lower surface 3f of the piston ring groove bottom upper step 3d extends over the entire circumference with the spring seal ring 6. Abut and seal. In particular, if the axial width of the upper portion 3d of the piston ring groove bottom is set to be substantially equal to the axial width of the spring seal ring 6 and the gap between them is substantially zero, the leakage amount is very small. Also, due to the presence of the gap 11 on the inner circumference, the abutment portion 10 of the spring seal ring 6 does not open even during thermal expansion, and due to the presence of the gap 13, the piston 2 behaves close to the wall surface 1 a of the cylinder 1. Also, the spring seal ring 6 does not slide on the wall surface 1a.

Therefore, reliable sealing performance can be obtained while reducing friction loss.

FIG. 3 shows a second embodiment of the present invention. In the second embodiment, the lower surface 3f of the piston ring groove bottom upper step 3d is not a horizontal surface but a dish-shaped inclined surface corresponding to the torsion angle of the cross section of the spring seal ring 6. Thereby, the spring seal ring 6 is always in surface contact with the lower surface 3f, which is advantageous in abrasion resistance and seizure resistance.

FIG. 4 shows a third embodiment of the present invention in which the second embodiment is partially modified. In the third embodiment, the outer peripheral lower surface side portion 6b of the spring seal ring 6 pressed against the upper surface 9b of the tapered cross-section ring 9 and the inner peripheral upper surface portion 6a of the spring seal ring 6 pressed against the upper surface 3a of the piston ring groove 3 are formed. , Each horizontal plane or piston 2
Is machined to a plane orthogonal to the central axis of.

Therefore, according to the third embodiment, the outer peripheral lower surface side portion 6b and the inner peripheral upper surface side portion 6a of the spring seal ring 6 come into surface contact with the upper surface 9b of the tapered section ring 9 and the upper surface 3a of the piston ring groove 3. This is advantageous in abrasion resistance and seizure resistance.

FIG. 5 shows a fourth embodiment of the present invention in which the second embodiment is partially modified. In the fourth embodiment, the outer peripheral lower surface side portion 6b of the spring seal ring 6 which presses against the upper surface 9b of the tapered cross-section ring 9 and the inner peripheral upper surface side portion 6a of the spring seal ring 6 which presses against the upper surface 3a of the piston ring groove 3 are formed. The upper surface 9b of the tapered section ring 9 and the upper surface 3a of the piston ring groove 3 are each formed into a gentle curved surface, more specifically, an R surface having a constant radius.

Therefore, according to the fourth embodiment, even when the piston 2 is inclined during operation and the relative posture with the tapered cross-section ring 9 changes, the contact portion of the spring seal ring 6, that is, the outer peripheral lower surface side Part 6b and inner peripheral upper surface side part 6a
Seals reliably while moving the contact position according to the relative behavior. Thereby, the sealing property and the wear resistance are simultaneously secured.

FIG. 6 shows a fifth embodiment of the present invention in which the fourth embodiment is partially modified. In the fifth embodiment, the outer surface of the spring seal ring 6 is resin-coated so that a coating layer is indicated by reference numeral 6d. As a material for this coating, a material having self-lubricating properties and abrasion resistance is used. As a result, the seal life is improved while maintaining the initial conformability.

FIG. 7 shows a sixth embodiment of the present invention in which the fifth embodiment is partially modified. In the sixth embodiment, a chamfered portion 9c is provided on the inner peripheral upper surface of the tapered cross-section ring 9.

When the chamfered portion 9c is formed on the inner peripheral upper surface of the tapered section ring 9 as described above, the tapered section ring 9 is formed.
Is twisted so that when mounted in the cylinder 1, the outer periphery thereof rises upward. Therefore, the spring seal ring 6 comes into more pressure contact with the outer peripheral lower surface side portion 6b, and the sealing performance at this portion is improved.

FIGS. 8 and 9 show a seventh embodiment of the present invention in which the sixth embodiment is partially modified. In the seventh embodiment, the abutment portion 2 of the tapered section ring 9
1 is a triangular prism-shaped projection 21a and a corresponding notch 2
1b. When the abutment portion 21 is formed in a double stepped shape in this way, the sealing performance at the abutment portion 21 is improved, oil consumption due to lubricating oil being brought into the combustion chamber side is suppressed, and the amount of gas leakage is reduced. Is reduced.

FIGS. 10 and 11 show an eighth embodiment of the present invention in which the abutment 10 of the spring seal ring 6 in the second embodiment is partially changed. In the eighth embodiment, one abutment surface 10a of the spring seal ring 6 is used.
A concave portion 10c is formed on the lower surface side of the opening, whereby the actual sealing surface of the abutment portion 10 is formed in a substantially U-shape that opens downward. The recess 10c is provided on the lower surface 3f of the piston ring groove bottom upper step 3d.
Is formed so as not to overlap with the outer peripheral edge 3c. According to the configuration of this embodiment, the sealing surface pressure at the abutment portion 10 is increased, and the sealing performance is improved.

FIG. 12 shows a ninth embodiment of the present invention in which the abutment 10 of the spring seal ring 6 in the eighth embodiment is partially modified. In the ninth embodiment, similarly to the eighth embodiment, a recess 10c is formed on the lower surface side of one abutment surface 10a, and the other abutment surface 10b is fitted into the recess 10c via a minute gap. A matable projection 10d is formed. The height of the convex portion 10d is set so that portions other than the concave portion 10c and the convex portion 10d abut as an actual sealing surface.

According to the structure of this embodiment, the fitting of the concave portion 10c and the convex portion 10d prevents displacement of the abutment portion 10, and improves the reliability of the seal. Since the actual sealing surface has a substantially U-shape as in the eighth embodiment, the sealing surface pressure also increases, and good sealing properties can be obtained.

FIG. 13 shows a tenth embodiment of the present invention in which the configuration of the tapered section ring 9 in the fifth embodiment is partially changed. In the tenth embodiment, a coiled spring 31 is arranged as an expander on the back side of the tapered cross-section ring 9. In order to accommodate the coil spring 31, the tapered section ring 9 is required.
Has a substantially semicircular concave groove 32 on its back surface, the thickness of which is set small in the radial direction.

According to the structure of this embodiment, tension is positively applied to the tapered section ring 9 and the wall 1
The followability of the tapered cross-sectional ring 9 with respect to a is improved. This further reduces oil consumption.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a first embodiment of a combined piston ring device according to the present invention.

FIG. 2 is a perspective view showing the spring seal ring 6 in a free state (a) and a mounted state (b).

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

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

FIG. 5 is a sectional view showing a fourth embodiment of the present invention.

FIG. 6 is a sectional view showing a fifth embodiment of the present invention.

FIG. 7 is a sectional view showing a sixth embodiment of the present invention.

FIG. 8 is a sectional view showing a seventh embodiment of the present invention.

FIG. 9 is a perspective view showing an abutment portion 21 of the tapered cross-section ring 9 in the seventh embodiment.

FIG. 10 is a sectional view showing an eighth embodiment of the present invention.

FIG. 11 shows a spring seal ring 6 according to the eighth embodiment.
FIG.

FIG. 12 is a perspective view of an abutment portion 10 of a spring seal ring 6 according to a ninth embodiment of the present invention.

FIG. 13 is a sectional view showing a tenth embodiment of the present invention.

FIG. 14 is a sectional view showing an example of a conventional combination piston ring device.

FIGS. 15 (a) and (b) are cross-sectional views showing another example of a conventional combined piston ring device, and are cross-sectional views for explaining gas leakage due to gas pressure.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Cylinder 2 ... Piston 3 ... Piston ring groove 6 ... Spring seal ring 9 ... Tapered cross-section ring 10 ... Aperture 21 ... Aperture

Claims (12)

[Claims] 1. A combined piston ring device which is housed in a piston ring groove formed in a piston and has a joint portion and serves as a pressure piston ring, wherein the piston ring device is disposed on a lower surface side of the piston ring groove and has a tapered shape. A ring having a tapered cross-section in which the outer peripheral surface slides on the cylinder wall surface; and an upper surface on the inner peripheral surface is pressed against the upper surface of the piston ring groove, and a lower surface on the outer peripheral surface is pressed against the tapered cross-sectional ring. And a spring seal ring having a cross-sectional shape twisted in the shape of a disc spring, wherein the tapered cross-sectional ring is pressed toward the lower surface of the piston ring groove by the spring seal ring. 2. A bottom portion of the piston ring groove in which the lower portion of the piston ring groove accommodates the ring with the tapered cross-section and a spring seal ring which are smaller in diameter than the lower portion of the bottom of the piston ring groove. The upper part of the piston ring groove bottom is formed, and due to the difference in diameter of both,
2. The combination piston ring device according to claim 1, wherein a lower surface of the upper portion of the piston ring groove bottom is formed. 3. The combination piston ring device according to claim 2, wherein the axial width of the spring seal ring is set substantially equal to the axial width of the upper portion of the piston ring groove bottom. 4. The combination piston ring according to claim 2, wherein the lower surface of said piston ring groove bottom upper step forms a dish-shaped inclined surface corresponding to the torsion angle of the cross section of said spring seal ring. apparatus. 5. The spring seal ring has no gap at the abutment portion when the piston is mounted, and has a gap between the inner peripheral surface and the piston ring groove bottom surface and between the outer peripheral surface and the cylinder wall surface. 2. The combination piston ring device according to claim 1, wherein the combination is secured. 6. In the spring seal ring, an inner peripheral upper surface portion in contact with the upper surface of the piston ring groove and an outer peripheral lower surface portion in contact with the tapered cross-section ring form planes parallel to the piston ring groove upper surface, respectively. 2. The combination piston ring device according to claim 1, wherein: 7. The spring seal ring has an inner peripheral upper surface portion in contact with the upper surface of the piston ring groove and an outer lower surface side portion in contact with the tapered cross-section ring, respectively, with respect to the piston ring groove upper surface and the tapered cross-section ring upper surface. 2. The combined piston ring device according to claim 1, wherein the combined piston ring device has a gently curved surface circumscribed. 8. The combination piston ring according to claim 1, wherein at least one abutment surface of the spring seal ring is formed as a substantially U-shaped seal surface that opens downward. apparatus. 9. The combination piston ring device according to claim 8, wherein a concave portion is formed on one side of the abutment surface and a convex portion is formed on the other side. 10. The combination piston ring device according to claim 1, wherein an outer surface of said spring seal ring is coated with a resin. 11. The combination piston according to claim 1, wherein a chamfered portion is provided on an inner peripheral upper surface portion of the tapered cross-section ring so as to compensate for a downward pressing force by the spring seal ring. Ring device. 12. The combined piston ring device according to claim 1, wherein a joint portion of the ring with the tapered cross section has a double stepped shape.