JPH0738809U - Piston ring structure - Google Patents

Abstract

(57) [Summary] [Object] To provide a piston ring structure in which the piston ring exhibits a sufficient sealing property with respect to the ring groove to improve the blow-by gas blocking function and to reduce the consumption of lubricating oil. [Structure] The outer peripheral side of the lower surface 5 of the piston ring 1 is a flat surface portion 15 that is a straight line in a cross section including the center line of the piston, and the inner peripheral side of the lower surface 5 is continuous with the flat surface portion 15 and has a semi-arc shape. A portion 16 is formed, and the outer peripheral side of the upper surface 2 of the piston ring 1 is configured as a cut surface 13 adapted to the twist angle (α) of the piston ring 1.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a piston ring structure used for an internal combustion engine of an automobile or the like. In particular, the inner peripheral side of the upper surface of the piston ring is cut to provide an inner bevel portion, which creates an imbalance in the internal tension in the piston ring and twists the piston ring itself to scrape off the lubricating oil. The present invention relates to a so-called twist design ring piston ring structure having improved functions.

[0002]

[Prior art]

Conventionally, a piston ring structure of this type is, for example, according to Japanese Utility Model Publication No. 58-9925, as shown in FIGS. 4 and 5, the upper surface 22 of the piston ring 21 is formed into a flat portion and the inner peripheral side thereof is cut to form an inner bevel. The lower surface 25 of the piston ring is formed in an arcuate shape whose central portion projects downward when viewed in a cross section including the center line of the piston 26. Then, in a normal state where the piston ring 21 does not receive an explosion pressure (state of FIG. 4), the lower surface 25 of the piston ring 21 forms an arc of radius R ₁ with the point O above it as the center. The lower surface 25 of the piston ring 21 is in contact with the lower surface 27 of the ring groove at the fulcrum P ₁ . From such a state, when the piston ring 21 shifts to the stroke (state of FIG. 5) in which the explosion pressure in the direction of the arrow is received, the fulcrum P ₁ between the lower surface 25 of the piston ring 21 and the ring groove lower surface 27 is continuous. When the piston ring 21 rolls on the ring groove lower surface 27, the impact force between the two surfaces 25 and 27 is reduced to prevent the ring groove lower surface 27 from being worn.

[0003]

[Problems to be solved by the device]

 However, in such a conventional piston ring structure, since the outer peripheral corners of the upper surface 22 of the piston ring 21 are substantially right angles, the piston ring 21 shown in FIG. In this state, the outer peripheral corners of the upper surface 22 of the piston ring 21 make line contact with the ring groove upper surface 28, and a concentrated load is applied to the ring groove upper surface 28 to cause uneven wear, which increases the amount of lubricating oil consumed. Further, when the explosion pressure in the direction of the arrow is acting on the piston ring 21 shown in FIG. 5, the lower surface 25 of the piston ring 21 and the lower surface 27 of the ring groove are still in line contact with each other, and sufficient sealing performance can be obtained. However, the blow-by gas may increase.

In view of the above points, the present invention provides a piston ring structure in which the piston ring exhibits sufficient sealability with respect to the ring groove, improves the blow-by gas blocking function, and reduces the amount of lubricating oil consumed. The purpose is to

[0005]

[Means for Solving the Problems]

 In the piston ring structure of the present invention, the lower surface outer peripheral side of the piston ring is a flat surface portion which is a straight line in a cross section including the center line of the piston, and the lower surface inner peripheral side is continuous with this flat surface portion and has a semi-arc shape. The outer peripheral side of the upper surface of the piston ring is formed as a cut surface adapted to the twist angle of the piston ring.

[0006]

[Action]

 With this structure, in a normal state where the piston ring is not subjected to explosive pressure, the outer peripheral surface of the upper surface of the piston ring is a cut surface that matches the twist angle of the piston ring, so the contact with the upper surface of the ring groove becomes surface contact. . Also, when the piston ring receives an explosive pressure, the inner peripheral side of the lower surface of the piston ring has a semi-circular shape, so the contact with the lower surface of the ring groove is a flat surface. There will be surface contact.

[0007]

【Example】

 Next, an embodiment of the present invention will be described with reference to FIGS.

FIG. 1 is a longitudinal sectional view showing a part of a piston ring structure according to an embodiment of the present invention, and FIG. 2 is a state in which the piston ring of FIG. 1 is attached to a piston including a center line of the piston ring. FIG. 3 is a sectional view at the time of normal operation, and FIG. 3 is a sectional view at the time of the explosion stroke.

In the figure, 1 is a piston ring, and this piston ring 1 is inserted into an annular ring groove 10 formed in the crown portion of a piston 6, and is inserted between the piston 1 and the cylinder inner wall 11. .

The lower surface 5 of the piston ring 1 has a flat surface portion 15 on its outer peripheral side that is a straight line in a cross section including the center line of the piston 6, and further has an inner peripheral surface connected to the flat surface portion 15. A semi-circular shape 16 having a radius R is formed.

The upper surface 2 of the piston ring is cut at its inner peripheral side to form an inner bevel portion 4 having the twist angle (α) of the piston ring 1. The outer peripheral side is a flat surface portion 3 continuous with the inner bevel portion 4, but the outer peripheral side corner angle is formed as a cut surface 13 adapted to the twist angle (α) of the piston ring 1.

Next, the operation of this embodiment will be described.

In a normal state where the explosion pressure is not applied to the piston ring 1 shown in FIG. 2, the piston ring 1 is twisted by the twist angle (α) by the inner bevel portion 4, and the cut surface 13 faces the ring groove upper surface 8. By making contact, the sealability between the cut surface 13 and the ring groove upper surface 8 is secured, and the consumption of lubricating oil is suppressed. Further, since the cut surface 13 comes into surface contact with the ring groove upper surface 8, uneven wear of the ring groove upper surface 8 is avoided, and from this point as well, an increase in blow-by gas and lubricating oil consumption is suppressed.

Further, when the explosion pressure (in the direction of the arrow in FIG. 3) acts on the piston ring 1 shown in FIG. 3, the piston ring 1 is pressed against the ring groove lower surface 7 side, but in this state The outer peripheral side of the lower surface of the piston ring 1 is a flat surface portion 15 which is a straight line in a cross section including the center line of the piston 6, and the inner peripheral side is a semi-circular shape 16 continuous with the flat surface portion 15. In relation to the lower surface 7, the semi-circular shaped portion 16 does not contact the ring groove lower surface 7, but the flat surface portion 15 contacts. As a result, the flat surface portion 15 and the ring groove lower surface 7 come into surface contact with each other, so that the sealability between them is sufficiently enhanced and the blow-by gas is not increased.

[0015]

[Effect of device]

 In the piston ring structure according to the above configuration, the lower surface outer peripheral side of the piston ring is a flat part that is a straight line in the cross section including the center line of the piston and the lower surface inner peripheral side is continuous with this flat part and has a semi-arc shape. In addition, since the outer peripheral surface of the upper surface of the piston ring is configured as a cut surface that matches the twist angle of the piston ring, in a normal state where the piston ring is not subjected to explosive pressure, the piston ring on the outer peripheral surface of the upper surface of the piston ring is Since the cut surface that matches the twist angle makes surface contact with the upper surface of the ring groove to improve the sealing performance between the two and reduce the consumption of lubricating oil, the cut surface makes surface contact with the upper surface of the ring groove. By avoiding uneven wear on the upper surface of the ring groove, it is possible to prevent the blow-by gas and the consumption of lubricating oil from increasing.

Further, when the piston ring receives an explosion pressure, the inner peripheral side of the lower surface of the piston ring has a semi-circular shape, so the contact with the lower surface of the ring groove is a flat surface, which results in the lower surface of the ring groove. Since they are in surface contact with each other, the sealing property is sufficiently enhanced and the blow-by gas is not increased. .

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view showing a part of a piston ring structure according to an embodiment of the present invention.

FIG. 2 is a sectional view showing a state in which the piston ring of FIG. 1 is inserted into a piston at a normal time including a piston ring center line.

FIG. 3 is a cross-sectional view showing a state where the piston ring of FIG. 1 is inserted into a piston during an explosion stroke including a piston ring center line.

FIG. 4 is a sectional view showing a state in which a conventional piston ring is inserted into a piston at a normal time including a piston ring center line.

FIG. 5 is a cross-sectional view showing a state in which a conventional piston ring is inserted into a piston during an explosion stroke including a piston ring center line.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Piston ring 2 Upper surface 3 Flat surface part (upper surface side) 4 Inner bevel part (upper surface side) 5 Lower surface 6 Piston 13 Cut surface (upper surface side) 15 Flat surface part (lower surface side) 16 Semi-arcuate part (lower surface side)

Claims (1)

[Scope of utility model registration request] 1. A piston ring has a lower surface outer peripheral side which is a flat surface section which is straight in a cross section including a center line of the piston, and a lower surface inner peripheral side which is continuous with the flat surface section and has a semi-arc shape. Piston ring structure characterized in that the outer peripheral side of the upper surface is a cut surface that matches the twist angle of the piston ring.