JPH09170658A - Stopper structure of combined oil ring - Google Patents

Abstract

PROBLEM TO BE SOLVED: To employ a general coil expander and secure sufficient strength of a stopper. SOLUTION: This combined oil ring 10 is constituted of an oil ring 11 and a coil expander 12, and a curved rod 27 is passed through the coil expander 12, being laid across a pair of abutment end parts 24, 25. A stopper member 30 is constituted of a hole inserting part 31 and a part 32 to be clamped which protrudes from one end of the hole inserting part 31. Two surfaces 32a, 32b of the part 32 to be clamped which are parallel to each other is held between a pair of abutment end parts 12a, 12b of the coil expander 12 and the hole inserting part 31 is fixed in a stopper member fixing hole 34 which is formed at the oil ring groove bottom surface 5 of a piston 1. The curved rod 27 is passed through a curved rod inserting hole 33 formed in the part 32 to be clamped. The hole inserting pave 31 may be inserted in the oil relief hole of the piston 1. A notch may be formed at the part to be clamped in place of the curved rod inserting hole.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a detent structure for a combined oil ring of an internal combustion engine.

[0002]

2. Description of the Related Art A port hole is opened on the inner peripheral surface of a cylinder of a two-cycle engine. When the ring rotates in the circumferential direction and the abutment is aligned with the port hole position, the ring abutment projects outward by self-tension. When the ring moves up and down in this state, the abutment end may be caught in the port hole.

Further, in an engine having a cylinder axis inclined horizontally or nearly horizontally, when the ring rotates and the abutment is located below, lubricating oil penetrates into the combustion chamber through the abutment while the engine is stopped. When the engine is started in this state, white smoke is generated and the consumption of lubricating oil is increased.

By rotating the ring in the circumferential direction,
Due to the above-mentioned problems, the ring rotation preventing means may be adopted.

The situation in which a ring detent is adopted in various engines is as follows.・ Ring detents are not generally adopted for construction machinery and ship diesel engines that are rarely started and stopped. -Of the gasoline engines for automobiles that often start and stop,
In an engine where the cylinder axis is tilted horizontally or nearly horizontally,
Ring detents are commonly used.・ Diesel engines with horizontal or near-horizontal cylinders were rarely used for automobiles in the past, so ring detents were not adopted, but recently this type of engine was used for automobiles. It has come to be used.

As a detent for a two-piece combination oil ring consisting of an oil ring and a coil expander, The actual exploitation number 57-31546 is known. According to Japanese Utility Model Laid-Open No. 57-31546, the coil wire is projected and extended inward and outward in the radial direction at both ends of the coil expander, and the extended portion is formed in an oil hole formed in an oil ring and a piston. The detent means inserted into the oil escape hole and the detent hole are described.

[0007]

However, the above detent structure has the following problems. In a general coil expander, the outer peripheral surface of the coil expander is centerless ground in order to reduce the contact surface pressure between the coil expander and the oil ring. However, in the above structure, the coil wires in the both ends of the coil expander are oriented in the radial direction and protrude from the outer circumference of the coil expander, so that it is difficult to polish the outer peripheral surface of the coil expander.・ The stability of the abutment abutting part is poor because the abutment end face of the coil expander cannot be processed. -The tension cannot be adjusted by changing the total length of the coil expander after forming the coil expander. -Coil wires inserted into the oil hole of the oil ring and the oil relief hole of the piston are thin, so the strength of the rotation-stopping part cannot be secured sufficiently.・ When assembling the combined oil ring into the oil ring groove of the piston, it is necessary to adjust the circumferential position of the oil ring to be installed after the coil expander, so the assemblability is poor.

An object of the present invention is to provide a detent structure for a combined oil ring which can adopt a general coil expander and can sufficiently secure the strength of a detent part.

[0009]

It has been known from prior experience that the coil expander and the oil ring do not rotate relative to each other during operation of the engine. Therefore, if the coil expander is prevented from rotating with respect to the piston,
The oil ring can be stopped.

Therefore, in order to achieve the above object,
According to the present invention, an oil ring having a substantially I-shaped cross section in which a pair of upper and lower rails extending in the circumferential direction are connected by a pillar portion, and an oil ring disposed on the inner peripheral side of the oil ring are urged outward in the radial direction. In a combined oil ring including a coil expander, one end of a rotation stop member is sandwiched by a pair of abutment end faces of the coil expander, and the other end of the rotation stop member is formed at the bottom of an oil ring groove of a piston. It is characterized in that it is inserted into the hole.

It is desirable that the detent member has two surfaces parallel to each other at one end, and these two surfaces are sandwiched by a pair of abutment end surfaces of the coil expander.

When the curved bar is inserted through the coil expander so as to straddle the ends of the abutment, a hole or notch is formed at one end of the detent member, and the hole or notch is formed. Make sure the curved bar is inserted through the notch.

The hole into which the other end of the detent member is inserted may be an oil relief hole formed in the bottom of the oil ring groove of the piston, or may be dedicated to the bottom of the oil ring groove separately from the oil relief hole. The holes may be formed.

As described above, since the other end, that is, the inner end of the detent member is inserted into the hole formed in the bottom of the oil ring groove, the detent member is located in the oil ring groove in the circumferential direction. Maintained in place. Since one end of the anti-rotation member, that is, the outer end is held by the pair of abutment end faces of the coil expander, the coil expander is prevented from rotating in the circumferential direction. As a result, the oil ring pressed by the coil expander in the radial direction is also prevented from rotating.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION With reference to FIGS. 1 and 3, a description will be given of an anti-rotation structure for a two-piece type combined oil ring which is an embodiment of the present invention.

The piston 1 shown in the figure is for a horizontal engine in which a cylinder 2 is horizontally arranged, and is combined with an oil ring groove 3 formed in an outer peripheral surface of the piston 1 in the cylinder 2 to form a combined oil ring. 10 is installed. 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 steel ring having a substantially I-shaped cross section, and has a pair of upper and lower rails 13 extending in the circumferential direction.
14 and a thin straight column portion 15 extending in the circumferential direction and connecting the pair of rails 13 and 14.
The outer peripheral surfaces 16 and 17 of the upper and lower rails 13 and 14 contact with the inner peripheral surface 4 of the cylinder 2 to form sliding surfaces for scraping off the oil on the inner peripheral surface 4 of the cylinder 2. Pillar 15 and upper and lower rails 1
The outer peripheral groove 18 formed by the outer peripheral side projections of the rails 3, 14 is an oil receiving groove, and the outer peripheral surface 1 of the upper and lower rails 13, 14 is
The oil scraped off from the inner peripheral surface 4 of the cylinder 2 at 6, 17 passes from the outer peripheral groove 18 through the plurality of oil holes 19 formed in the column portion 5 at equal intervals in the circumferential direction. It moves to the inner peripheral side of the ring 11 and is dropped into the oil pan through a plurality of oil escape holes formed in the bottom surface 5 of the oil ring groove 3 of the piston 1.

A coil expander 12 is mounted in an inner peripheral groove 20 formed by the protrusions on the inner peripheral side of the upper and lower rails 13 and 14 and the column portion 15, and the oil ring 11 is radially outwardly moved. It is designed to be pressed and urged. The coil expander 12 is formed by winding a wire rod having a circular cross section into a coil shape and grinding the outer peripheral surface of the coil into a ring shape. Therefore, in the drawing, the cross section of the wire is formed in a shape in which the outer peripheral side of the circle is cut out. The grinding surface 21 is configured to come into contact with the inclined surfaces 22 and 23 of the inner peripheral side protruding portion forming the inner peripheral groove 20 of the oil ring 11. In addition, the pair of abutment ends 24, 2 of the coil expander 12
The end faces 12a and 12b of No. 5 are parallel to each other and are formed as flat surfaces parallel to the axial direction. A curved rod 27 is inserted into the circumferential hole 26 of the coil expander 12 so as to extend over the pair of abutment ends 24 and 25 of the coil expander 12. The cross-sectional shape of the wire material forming the coil expander 12 is not limited to that shown above, and may be circular or rectangular, for example.

Next, the rotation preventing member 30 (see FIG. 3A) will be described. The rotation stopping member 30 is a pin-shaped component in which the outer periphery of one end of the round bar is cut from both sides by the same amount, and the round bar-shaped hole insertion part 31 and the one end face of the hole insertion part 31 protrude. And a clamped portion 32 having a plate shape. Two opposing surfaces 32a of the sandwiched portion 32,
32b is formed as a plane parallel to each other. A curved rod insertion hole 33 is formed through the sandwiched portion 32 in the thickness direction, and the curved rod insertion hole 33 is formed in the coil expander 1.
The second circumferential hole 26 has substantially the same width as that of the second circumferential hole 26 and is long in the projecting direction, and has both ends formed into arc-shaped long holes.

On the bottom surface 5 of the oil ring groove 3 of the piston 1, a detent member fixing hole 34, which is closed at one end, is formed inward in the radial direction separately from the oil escape hole. The insertion portion 31 has a hole 34 for fixing the rotation preventing member.
The outer diameter is slightly larger than the inner diameter of the. The hole insertion portion 31 of the detent member 30 has a detent member fixing hole 34.
The fixed portion 32 of the anti-rotation member 30 is radially protruded from the bottom surface 5 of the oil ring groove with the two parallel surfaces 32a and 32b arranged in the circumferential direction.

The coil expander 12 has a pair of abutment end faces 12a, 12b in the oil ring groove 3 of the piston 1.
Is attached in a state in which it is butted against two mutually parallel surfaces 32a and 32b of the sandwiched portion 32 of the anti-rotation member 30 and is contracted, and an expansion force outward in the radial direction is generated. A curved rod 27 is inserted into the circumferential hole 26 of the coil expander 12 so as to straddle the pair of abutment end portions 24 and 25. The curved rod 27 is further covered by the rotation preventing member 30. The curved rod insertion hole 33 formed in the holding portion 32 is inserted.

The oil ring 11 is a coil expander 1.
The outer peripheral surfaces 16 and 17 of the upper and lower rails 13 and 14 are pressed against the inner peripheral surface 4 of the cylinder 2 by being pressed and urged radially outward by 2.

As described above, the detent member 30 is fixed in the oil ring groove 3, and the detent member 30 is sandwiched by the coil expander 12.
The coil expander 12 is prevented from rotating in the circumferential direction. As a result, the oil ring 11 that is biased by the coil expander 12 is also prevented from rotating in the circumferential direction.

In the above embodiment, the inner diameter of the rotation preventing member fixing hole 34 is made slightly smaller than the outer diameter of the hole insertion portion 31 of the rotation preventing member 30 so that the rotation preventing member 30 is fixed. It is fixed to, but not limited to this. The inner diameter of the hole formed in the oil ring groove bottom surface 5 of the piston 1 may be made larger than the outer diameter of the hole insertion portion 31 of the rotation preventing member 30. Of course, both diameters may be the same.

FIG. 2 shows a detent structure for a two-piece combination oil ring which is another embodiment of the present invention. The difference from the above embodiment is that the detent member 3 is provided.
It is in the hole on the piston 1 side into which the 0 hole insertion part 31 is inserted. In the present embodiment, the oil escape hole 6 formed in the bottom surface 5 of the oil ring groove 3 of the piston 1 is used as the hole into which the hole insertion portion 31 of the detent member 30 is inserted. That is, the hole insertion portion 31 of the detent member 30 in which the held portion 32 is sandwiched between the pair of abutment end faces 12a and 12b of the coil expander 12 is inserted into the oil escape hole 6 on the piston 1 side. In addition, the rotation stopping member 3
In the present embodiment, the curved rod insertion hole 33 formed in the clamped portion 32 of 0 has a circumferential hole 26 in the coil expander 12.
Although it is a circular hole having an inner diameter slightly larger than that, it may be a long hole as shown in the above embodiment.

Since the oil escape hole 6 is formed to be larger than the outer diameter of the hole insertion portion 31 of the whirl-stop member 30, the hole insertion portion 31 of the whirl-stop member 30 is not fixed to the oil escape hole 6, but is circular. Oil escape hole 6 for movement in the circumferential direction
Since it is blocked by the inner peripheral wall of the coil expander 12, it is possible to prevent the coil expander 12 from rotating in the circumferential direction. as a result,
The oil ring 11 is also prevented from rotating in the circumferential direction.

In the two embodiments described above, the curved rod insertion hole is formed in the held portion of the rotation preventing member, but as shown in FIG. 3B, the curved rod insertion hole is formed. Instead of forming the above, a linear notch 35 having a width slightly wider than the curved rod 27 is formed along the protruding direction from the tip of the held portion 32, and the curved rod 27 is inserted through the notch 35. May be.

In the above two embodiments, the hole inserting portion of the rotation preventing member has a round bar shape, but the shape of the rotation preventing member is not limited to those shown in the above two embodiments, and for example, The hole inserting portion and the held portion of the rotation preventing member may be formed in a single plate shape.

Further, in the above two embodiments, the detent of the combined oil ring when the curved rod 27 is inserted through the coil expander 12 is shown, but when the curved rod is not used, FIG. ), It is not necessary to form the curved rod insertion hole or the notch in the held portion 32 of the rotation preventing member 30.

Incidentally, a prior application of the same applicant (Japanese Patent Application No. 7-
No. 124262), in order to directly prevent the oil ring from rotating, a locking piece to be inserted into the oil hole of the oil ring is formed at the tip of the rotation preventing member so that the strength of the rotation preventing portion is sufficiently secured. It is difficult to do so, and if the oil ring has a small radial thickness, the locking piece may come off from the oil hole during operation. On the other hand, according to the present invention, since the locking piece to be inserted into the oil hole of the oil ring does not need to be projectingly formed in the rotation preventing member, the strength of the rotation preventing portion can be sufficiently secured.

[0031]

As described above, according to the present invention, there is provided a combination oil ring detent structure which can employ a general coil expander and can sufficiently secure the strength of the detent part. it can.

[Brief description of the drawings]

FIG. 1 shows a rotation preventing structure of a two-piece type combined oil ring according to an embodiment of the present invention, (a) is a partial sectional plan view, and (b) is a vertical sectional view.

FIG. 2 shows a rotation preventing structure for a two-piece type combined oil ring which is another embodiment of the present invention, (a) is a partial cross-sectional plan view, and (b) is a vertical cross-sectional view.

3 (a), (b) and (c) are perspective views showing a detent member, respectively.

[Explanation of symbols]

 1 Piston 2 Cylinder 3 Oil Ring Groove 4 Cylinder Inner Surface 5 Oil Ring Groove Bottom 6 Oil Relief Hole 10 Combination Oil Ring 11 Oil Ring 12 Coil Expander 12a, 12b Joint End Face 13, 14 Rail 15 Pillar 16, 17 Outer Surface 18 Outer peripheral groove 19 Oil hole 20 Inner peripheral groove 21 Grinding surface 22, 23 Sloping surface 24, 25 Abutment end 26 Circumferential hole 27 Curved bar 30 Detent member 31 Hole insertion part 32 Clamped part 32a, 32b Flat surface 33 Curved rod insertion hole 34 Hole for fixing anti-rotation member 35 Notch

Claims (5)

[Claims] 1. An oil ring having a substantially I-shaped cross section in which a pair of upper and lower rails extending in the circumferential direction are connected by a column portion, and an oil ring arranged on the inner peripheral side of the oil ring and biased outward in the radial direction. A structure in which a combined oil ring consisting of a coil expander is prevented from rotating in the oil ring groove of the piston, and one end of the rotation preventing member is sandwiched by a pair of end faces of the coil expander, and the rotation preventing member is The other end portion of the combined oil ring is inserted into a hole formed in the bottom of the oil ring groove of the piston to prevent the combined oil ring from rotating. 2. The two surfaces that are parallel to each other are formed at one end of the anti-rotation member, and the two surfaces are sandwiched by a pair of abutment end surfaces of the coil expander. A combination oil ring rotation stop structure as described in 1. 3. A hole or a notch is formed at one end of the detent member, and the curved rod is arranged so as to pass through the coil expander and straddle between the abutment ends. 3. The combination oil ring rotation preventing structure according to claim 1, wherein a hole or a notch formed at one end of the rotation preventing member is inserted. 4. The hole according to claim 1, wherein the hole into which the other end of the detent member is inserted is an oil escape hole formed at the bottom of the oil ring groove of the piston. Anti-rotation structure of combined oil ring. 5. The hole into which the other end of the detent member is inserted is a hole formed separately from the oil escape hole at the bottom of the oil ring groove of the piston.
The rotation preventing structure for the combined oil ring according to 2, or 3.