JP2011163431A - Combined oil ring - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To give a locking function to a two-piece combined oil ring and to improve assemblability. <P>SOLUTION: The combined oil ring 10 comprises an oil ring 11 of roughly I shape in cross section, two upper and lower rails 13, 14 which are connected with a pillar part 15, and an coil expander 12 which presses and energizes the oil ring 11 outside in the radial direction. In this oil ring, a locking member 21 is fixed to at least one of the upper surface 11b and lower surface 11a of the oil ring 11 and is structured in such a way that it can be inserted into a recessed part 22 formed on the surface of a ring groove 4 of a piston 1 and opened to the outer circumferential surface 3 of the piston 1, and the locking member 21 protrudes inward in the radial direction from the inner circumferential end of the oil ring 11. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a two-piece combination oil ring having a detent function.

  If a combined oil ring is used in an engine with the cylinder shaft level or near-horizontal, if the ring rotates and the joint is located below, oil will enter the combustion chamber through the joint while the engine is stopped. . When the engine is started in this state, white smoke is generated or oil consumption increases.

  Since the above-mentioned problem occurs when the ring rotates in the circumferential direction, a ring detent means may be employed. A technique shown in Patent Document 1 is known as a prior art that employs the rotation preventing means. In Patent Document 1, in a two-piece type combined oil ring, a rotation preventing member is fixed to the lower surface or the upper surface of the oil ring, and a recess into which the rotation preventing member is inserted is formed on the ring groove surface of the piston.

JP-A-9-317885

  The anti-rotation structure of Patent Document 1 has a problem in terms of the assembling property of the combination oil ring, and no two-piece combination oil ring has been put to practical use.

  An object of the present invention is to provide a two-piece type combination oil ring with a detent function and to improve the assemblability.

In order to solve the above problems, the present invention employs the following means. That is,
The present invention comprises an oil ring having a substantially I-shaped cross section in which two upper and lower rails are connected by a column portion, and a coil expander that presses and urges the oil ring radially outward. In the combined oil ring, the anti-rotation member is fixed to at least one of the lower surfaces, and the anti-rotation member can be inserted into a recess formed in the ring groove surface of the piston and opened in the outer peripheral surface of the piston. The member protrudes radially inward from the inner peripheral end of the oil ring.

  The anti-rotation member preferably has an axial height of 0.5 to 1.0 mm and an inner peripheral protrusion length of 2.0 to 3.0 mm. If the axial height of the non-rotating member is less than 0.5 mm, the rigidity of the member is insufficient, and if it exceeds 1.0 mm, the recess depth of the ring groove surface of the piston becomes deep and the strength of the land portion of the piston decreases. Therefore, it is not preferable. If the inner peripheral protrusion length of the rotation preventing member is less than 2.0 mm, the rotation preventing member may come off from the concave portion of the ring groove surface in a free state before being inserted into the cylinder, and the assembling property is lowered. 3.0 mm is sufficient.

  The anti-rotation member is preferably fixed to the oil ring by welding or an adhesive. Further, the anti-rotation member may be fixed by being fitted to a protrusion formed integrally with the oil ring. In this case, the oil ring is preferably subjected to surface hardening treatment only on the outer peripheral surface. The anti-rotation member is preferably located at the joint end of the oil ring.

  According to the present invention, when the rotation preventing member of the oil ring is inserted into the recess formed in the ring groove surface of the piston, the movement of the oil ring in the circumferential direction is restricted. Is maintained at a predetermined position in the circumferential direction.

  Moreover, according to this invention, the assembly | attachment property of a combination oil ring is favorable. That is, when the combined oil ring is mounted on the piston, even if the oil ring inner periphery at the position of the rotation preventing member protrudes from the outer periphery of the piston due to the misalignment between the piston and the oil ring, the rotation preventing member is Since the protrusion protrudes inwardly, a part of the detent member remains in the recess formed in the ring groove surface of the piston. As a result, the piston fitted with the combination oil ring can be easily inserted into the cylinder bore.

  The anti-rotation member can be securely fixed to the oil ring by fixing it to the oil ring with welding or an adhesive. Further, if the anti-rotation member is fitted to a protrusion formed integrally with the oil ring, it can be easily fixed to the oil ring. In this case, if the oil ring is subjected to a surface hardening process only on the outer peripheral surface, the protrusion forming part is not subjected to the surface hardening process, so that the protrusion can be easily processed. If the anti-rotation member is located at the joint end of the oil ring, it becomes easy to align the anti-rotation member of the oil ring and the concave portion of the ring groove surface of the piston, and the assembling property of the combined oil ring is improved.

1 shows an embodiment of the present invention, (a) is a longitudinal sectional view showing a state where a piston fitted with a combination oil ring is inserted into a cylinder, (b) is a front view showing an oil ring portion of the piston, (c). FIG. 4 is a bottom view of a part of the oil ring. It is a perspective view which shows another example of a rotation prevention member.

    Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

  In FIG. 1, a piston 1 is for a horizontally installed engine in which a cylinder 2 is horizontally arranged. A combination oil ring 10 is mounted in an oil ring groove 4 formed on the outer peripheral surface 3 of the piston 1 in the cylinder 2. The combination oil ring 10 is a two-piece steel combination oil ring, and includes an oil ring 11 and a coil expander 12.

  The oil ring 11 is a ring having a substantially I-shaped cross section having an abutment, and includes a pair of upper and lower rails 13 and 14 extending in the circumferential direction and a column portion 15 extending in the circumferential direction and connecting the upper and lower rails 13 and 14. It has become. The oil ring 11 is formed of a hard steel wire, a piano wire, a stainless steel wire for springs, or the like. The outer peripheral surfaces 16 and 17 of the upper and lower rails 13 and 14 are in contact with the inner peripheral surface 5 of the cylinder 2 and constitute a sliding surface that scrapes off the oil on the inner peripheral surface 5 of the cylinder 2. The outer peripheral surfaces 16 and 17 of the oil ring 11 are not treated or are subjected to surface hardening treatment. As the surface hardening treatment, PVD coating, DLC coating, or nitriding only on the outer periphery is employed. The outer peripheral groove 18 formed by the column portion 15 and the upper and lower rails 13 and 14 is an oil receiving groove, and the oil scraped from the inner peripheral surface 5 of the cylinder 2 by the outer peripheral surfaces 16 and 17 of the upper and lower rails 13 and 14. Moves from the outer circumferential groove 18 to the inner circumferential side of the oil ring 11 through a plurality of oil holes 19 formed in the column portion 15 at intervals in the circumferential direction, and the oil ring groove 4 of the piston 1 Is dropped into an oil pan through a plurality of oil relief holes (not shown) formed in the bottom surface 6 of the oil.

  A coil expander 12 is mounted in an inner circumferential groove 20 formed by the upper and lower rails 13 and 14 and the column part 15 and presses and urges the oil ring 11 radially outward. The coil expander 12 is formed by winding a wire in a coil shape and further forming a ring shape.

  Therefore, the oil ring 11 is pressed and urged outward in the radial direction by the coil expander 12 so that the outer peripheral surfaces 16 and 17 of the upper and lower rails 13 and 14 are pressed against the inner peripheral surface 5 of the cylinder 2. .

  Next, the rotation prevention structure of the combination oil ring 10 will be described.

  The anti-rotation member 21 is fixed to the lower surface 11 a of one end of the oil ring 11 in a state of protruding radially inward from the inner peripheral end of the lower rail 14. The anti-rotation member 21 is fixed to the oil ring 11 by means such as welding or adhesive. The anti-rotation member 21 is a rectangular plate member, but the shape is not particularly limited.

  On the other hand, a recess 22 into which the rotation preventing member 21 is inserted is formed in the lower surface 4 a of the oil ring groove 4. The recess 22 extends to the outer peripheral surface 3 in the radial direction of the piston 1 and opens to the outer peripheral surface 3. Although the recessed part 22 has shown the recessed part of cross-sectional arc shape seeing from radial direction, cross-sectional shape is not specifically limited.

  In the oil ring 11, an anti-rotation member 21 is inserted into the recess 22 on the lower surface 4 a of the oil ring groove 4. Therefore, the rotation preventing member 21 of the oil ring 11 is engaged with the wall surface of the recess 22 in the lower surface 4a of the oil ring groove 4 to prevent the oil ring 11 from rotating in the circumferential direction.

  Moreover, the assembly | attachment property of the combination oil ring 10 is favorable. That is, when the combined oil ring 10 is mounted on the piston 1, the oil ring 11 has an inner diameter that is larger than when the cylinder 2 bore is inserted. Therefore, the inner periphery of the oil ring 11 at the position of the rotation preventing member 21 may jump out of the outer periphery of the piston 1 due to the misalignment between the piston 1 and the oil ring 11. Even in that case, since the rotation prevention member 21 protrudes inward from the inner peripheral end of the oil ring 11, a part of the rotation prevention member 21 is formed in the recess 22 formed in the lower surface 4 a of the oil ring groove 4 of the piston 1. stay. As a result, the piston 1 equipped with the combination oil ring 10 can be easily inserted into the cylinder 2 bore.

  Incidentally, the following problem occurs when the anti-rotation member does not protrude from the inner peripheral end of the oil ring. When the combined oil ring is mounted on the piston 1, the inner diameter of the oil ring is wider than when the cylinder 2 bore is inserted. 1 may protrude from the outer periphery, and the anti-rotation member may come off from the recess 22 on the lower surface 4a of the oil ring groove 4 of the piston 1. In that case, when the oil ring rotates in the circumferential direction and the detent member is displaced in the circumferential direction, the detent member becomes the oil ring of the piston 1 when the piston 1 equipped with the combined oil ring is inserted into the cylinder 2 bore. Since the position of the recess 22 formed in the lower surface 4a of the groove 4 does not match, the piston 1 fitted with the combination oil ring cannot be inserted into the cylinder 2 bore.

  The method for fixing the rotation preventing member 21 to the oil ring 11 is not limited to welding or an adhesive. For example, you may perform as follows. As shown in FIG. 2, a fitting groove 21 a is formed in the rotation preventing member 21. On the other hand, a fitting projection that protrudes downward in the axial direction from the lower surface 11a of the joint end portion of the oil ring 11 is formed by press working such as bending the inner peripheral side end portion of the joint portion in the lower rail 14 of the oil ring 11. The anti-rotation member 21 may be fixed to the lower surface 11 a of the oil ring 11 by fitting the fitting groove 21 a of the anti-rotation member 21 to the fitting protrusion.

  In the above embodiment, the rotation prevention is performed on the lower surface 11a side of the oil ring 11, but the present invention is not limited to this. An anti-rotation member may be provided on the upper surface 11 b side of the oil ring 11 and a recess may be formed on the upper surface 4 b of the oil ring groove 4 to prevent rotation on the upper surface side of the oil ring 11. Alternatively, rotation prevention may be performed on both the lower surface 11 a and the upper surface 11 b of the oil ring 11.

  1 .... Piston, 2 .... Cylinder, 3 .... Piston outer peripheral surface, 4 .... Oil ring groove, 4a ... Ring groove lower surface, 4b ... Ring groove upper surface, 5 .... Cylinder inner peripheral surface, 6 .... Ring Groove bottom, 10 ... combined oil ring, 11 ... oil ring, 11a ... oil ring lower surface, 11b ... oil ring upper surface, 12 ... coil expander, 13 ... upper rail, 14 ... lower rail, 15 .. Column part, 16, 17 .. Outer peripheral surface, 18 .. Outer peripheral groove, 19 .. Oil hole, 20 .. Inner peripheral groove, 21 .. Non-rotating member, 21 a. Recess.

Claims (6)

  An oil ring having a substantially I-shaped cross section in which two upper and lower rails are connected by a pillar portion, and a coil expander that presses and urges the oil ring radially outward, and at least one of an upper surface and a lower surface of the oil ring In the combined oil ring, the anti-rotation member can be inserted into a recess formed in the ring groove surface of the piston and opened in the outer peripheral surface of the piston. A combined oil ring that protrudes radially inward from the inner peripheral end of the oil.   The combined oil ring according to claim 1, wherein an axial height of the anti-rotation member is 0.5 to 1.0 mm, and an inner peripheral protrusion length is 2.0 to 3.0 mm.   The combined oil ring according to claim 1 or 2, wherein the anti-rotation member is fixed to the oil ring by welding or an adhesive.   4. The combined oil ring according to claim 1, wherein the rotation preventing member is fitted to a protrusion integrally formed with the oil ring.   The combined oil ring according to claim 4, wherein only the outer peripheral surface of the oil ring is subjected to a surface hardening treatment.   The combined oil ring according to any one of claims 1 to 5, wherein the anti-rotation member is located at a joint end of the oil ring.

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