Combination oil ring

Patent metadata

Field	Value
Publication number	US-10890255-B2
Application number	US-201816611616-A
Country	US
Kind code	B2
Filing date	Jul 30, 2018
Priority date	Jan 16, 2018
Publication date	Jan 12, 2021
Grant date	Jan 12, 2021

Abstract

Under a state in which the combination oil ring is mounted in an oil ring groove before inserted into a cylinder bore, when an inclined surface of an upper ear portion of an expander spacer is held in contact with an inner peripheral surface of an upper segment and an inclined surface of a lower ear portion of the expander spacer is held in contact with an inner peripheral surface of a lower segment, an upper protrusion amount (P1) from an outer peripheral-side end surface of the expander spacer to an outer peripheral surface vertex of the upper segment is larger than a lower protrusion amount (P2) from the outer peripheral-side end surface of the expander spacer to an outer peripheral surface vertex of the lower segment. When the combination oil ring is inserted into the cylinder bore, the sealing performance can be improved to reduce the oil consumption.

First claim

The invention claimed is:

1. A combination oil ring mounted in an oil ring groove of a piston and configured to be reciprocated inside a cylinder bore in an axial direction of a cylinder together with the piston, the combination oil ring comprising:
when a cylinder head side in the axial direction of the cylinder is an upper side and a side away from the cylinder head is a lower side,
an upper segment arranged on the upper side;
a lower segment arranged on the lower side independently of the upper segment; and
an expander spacer arranged between the upper segment and the lower segment, the expander spacer comprising:
an upper ear portion, which is formed at an upper part of an inner peripheral-side end portion so as to protrude upward therefrom, and has an inclined surface contacting with an inner peripheral surface of the upper segment and pressing the upper segment;
a lower ear portion, which is formed at a lower part of an inner peripheral-side end portion so as to protrude downward therefrom, and has an inclined surface contacting with an inner peripheral surface of the lower segment and pressing the lower segment;
an upper support portion, which is formed at an upper part of an outer peripheral-side end portion so as to protrude upward therefrom, and has an upper surface contacting with a lower surface of the upper segment and supporting the upper segment; and
a lower support portion, which is formed at a lower part of an outer peripheral-side end portion so as to protrude downward therefrom, and has a lower surface contacting with an upper surface of the lower segment and supporting the lower segment,

wherein the expander spacer excluding the upper ear portion and the lower ear portion has a maximum width in the axial direction of the cylinder, which is defined between an outer peripheral-side end portion of the upper support portion and an outer peripheral-side end portion of the lower support portion,
wherein a state in which the expander spacer, the upper segment, and the lower segment are mounted in the oil ring groove before being inserted into the cylinder bore is defined as a free state,
wherein, under the free state in which the inclined surface of the upper ear portion of the expander spacer is held in contact with the inner peripheral surface of the upper segment and the inclined surface of the lower ear portion of the expander spacer is held in contact with the inner peripheral surface of the lower segment on a cross section of the combination oil ring, which is taken along the axial direction of the cylinder,
when a protrusion amount from an outer peripheral-side end surface of the expander spacer to an outer peripheral surface vertex of the upper segment is an upper protrusion amount P1, a protrusion amount from the outer peripheral-side end surface of the expander spacer to an outer peripheral surface vertex of the lower segment is a lower protrusion amount P2, and a difference between the upper protrusion amount P1 and the lower protrusion amount P2 is P, a condition of P=P1−P2>0 is satisfied,
wherein, on the cross section of the combination oil ring, which is taken along the axial direction of the cylinder, under a state in which the combination oil ring is inserted into the cylinder bore, a center axis of the expander spacer is rotated and inclined upward at a predetermined angle over an entire circumference of the expander spacer in a circumferential direction of the combination oil ring, the inclined surface of the upper ear portion of the expander spacer is held in contact with the inner peripheral surface of the upper segment, the inclined surface of the lower ear portion of the expander spacer is held in contact with the inner peripheral surface of the lower segment, an upper surface of an inner peripheral surface-side part of the upper segment is held in pressure contact with the oil ring groove upper surface over an entire circumference of the upper segment, a lower surface of an inner peripheral surface-side part of the lower segment is held in pressure contact with the oil ring groove lower surface over an entire circumference of the lower segment, and the outer peripheral surface vertex of the upper segment and the outer peripheral surface vertex of the lower segment are held in pressure contact with a bore wall surface over the entire circumference of the upper segment and the entire circumference of the lower segment, respectively.

2. The combination oil ring according to claim 1 ,
wherein, when, in a radial direction of the combination oil ring,
a thickness of the upper segment is set to a1u [mm],
a thickness of the lower segment is set to a1d [mm],
a spacer thickness of the expander spacer on the upper segment side is set to a8u [mm], and
a spacer thickness of the expander spacer on the lower segment side is set to a8d [mm],
the following Expression (1), Expression (2), and Expression (3) are satisfied:
Q 1= a 1 u−a 8 u>P 1>0  (1)

Q 2= a 1 d - a 8 d>P 2>0  (2), and

when a condition of Q1-P1=Q1−P2 is satisfied, Q1−Q2=P1−P2 is established, and

Q
=

Q
⁢

⁢
1

-

Q
⁢

⁢
2

=

(

a
⁢

⁢
1
⁢
u

-

a
⁢

⁢
8
⁢
u

)

-

(

a
⁢

⁢
1
⁢
d

-

a
⁢

⁢
8
⁢
d

)

Assignees

• Tpr Co Ltd

Inventors

• HOSHINO Seeroku
• OSADA Hirofumi
• Tamaki Seiji

Classifications

• F16J9/064 Primary

  Rings with a flat annular side rail · CPC title

• F16J9/20

  Rings with special cross-section (L-section rings F16J9/02); Oil-scraping rings {(F16J9/06 takes precedence)} · CPC title

• F16J9/068 Primary

  corrugated in the axial direction · CPC title

• F02F5/00

  Piston rings, e.g. associated with piston crown · CPC title

• F16J9/06 Primary

  using separate springs {or elastic elements} expanding the rings; Springs therefor {; Expansion by wedging} · CPC title