JP4856574B2 - 2-piece oil ring wire and 2-piece oil ring - Google Patents

Description

  The present invention relates to a two-piece oil ring wire for an internal combustion engine.

  Conventionally, in a reciprocating internal combustion engine, a piston ring is used for sealing a combustion gas or lubricating oil. The piston ring has a pressure ring that seals the combustion gas and an oil ring that seals the oil. The oil ring is a so-called three-piece oil ring that is mainly used in engines that use gasoline as fuel. There is a so-called two-piece oil ring used in diesel engines. In both cases, the upper and lower rail sliding surfaces are brought into contact with the inner surface of the cylinder by a plate or coil spring from the inner peripheral side at a constant contact pressure, and the lubricating oil between the upper and lower rails is applied to the inner surface of the cylinder, and excess lubricating oil is applied. It plays the role of scraping off and forming an appropriate oil film. However, due to the demand for lower fuel consumption of automobile gasoline engines, the three-piece oil ring is in the direction of reducing the piston axial thickness, and as a result, the conventional three-piece oil ring has insufficient oil control performance. As a result, two-piece oil rings are also used in gasoline engines.

  The two-piece oil ring has two parts, a substantially M-shaped main body composed of a rail portion that slides on the cylinder inner surface and a column portion (hereinafter referred to as a web) connecting the inner surface and a coil spring for expanding the main body from the inner peripheral side. Consists of. The conventional two-piece oil ring main body has been machined from cast iron into a substantially M-shape by machining, and an oil passage hole is formed in the intermediate web in the vertical direction by cutting. However, in recent years, as the performance of the engine has been improved, the oil ring has also been required to have high strength, and the two-piece oil ring has been replaced from cast iron by steel. As a result, in a wire manufacturer, a round wire material is repeatedly annealed and rolled to form a substantially M-shaped deformed wire, and then an oil passage hole is provided in the web by perforation and cured by heat treatment. Thereafter, the piston ring maker performs coiling, cutting, outer periphery processing, surface treatment processing, and the like to form a two-piece oil ring main body.

  The surface pressure of the oil ring has been set several times higher than that of the pressure ring due to the role of the seal of the lubricating oil. However, reducing the frictional force of the oil ring is important in reducing the fuel consumption of automobile engines. It is in the direction of lowering the surface pressure. However, on the other hand, further reduction in oil consumption has been demanded. For this reason, it has become possible to review the shape of the outer peripheral sliding surface of the two-piece oil ring. This is because in a 4-cycle reciprocating internal combustion engine, the piston simply reciprocates on the inner peripheral surface of the cylinder, but four different steps of intake, compression, combustion, and exhaust are considered as one cycle, The functions required in each process are also different. Therefore, it is not necessary to have a symmetrical shape in the piston movement direction (piston ring vertical direction) as in the prior art, and it seems that a shape suitable for each of the above steps is desirable.

  As such a two-piece oil ring, for example, in Japanese Patent Laid-Open No. 9-144881, the shape of a combined oil ring that suppresses the lubricating oil scraping action during the piston ascending process and reduces the amount of lubricating oil consumption, The outer peripheral sliding surface of the upper and lower rails has a contact surface that slides with the inner peripheral surface of the cylinder, and a tapered surface that is disposed above the contact surface and has a diameter that decreases as the distance from the contact surface increases. That is, in such an oil ring, when the piston ring is lifted, it becomes easy to ride on the oil film by the tapered surface, and the sliding action of the lubricating oil on the rail sliding surface is suppressed and at the same time the sliding resistance is reduced. I can do it. Further, when the piston ring is lowered, the oil scraping ability is improved at the lower edge of the sliding surface, and the amount of lubricating oil consumption is reduced.

  In this way, when considering the improvement in the performance of the oil ring, in the case of a two-piece oil ring, a two-piece oil ring is formed in which the rail outer peripheral sliding surface shape is asymmetric in the piston ring vertical direction. It was. Under such circumstances, it has also been carried out to review the shape of the oil passage hole that is the path of the recovered lubricating oil.

  Japanese Patent Application Laid-Open No. 63-277844 discloses that the shape of the oil passage hole that does not impair the strength of the oil ring is made oval or rhombus so that the change in the secondary moment of inertia around the edge of the oil passage hole is moderated. It is disclosed that bulging that occurs when the oil ring is bent can be reduced.

  Japanese Patent Application Laid-Open No. 2006-22903 is intended to provide an oil ring capable of securing the area of the oil passage hole without impairing the strength of the oil ring having a thin oil ring axial height. The oil hole includes two arcs arranged so as to face both ends, two parallel straight parts arranged to have a distance in the width direction wider than the width of the arc part, and the arc part and the parallel part. And a skewed portion connecting the straight line portion.

  Japanese Patent Laid-Open No. 2003-286899 discloses a two-piece oil ring that can prevent combustion gas from leaking from an oil return hole of a piston, and an oil passage hole formed in the piston ring penetrates a rail below the oil ring. A two-piece oil ring main body characterized in that it communicates with the lower surface of the oil ring.

  Japanese Patent Application Laid-Open No. 2006-194272 relates to a two-piece oil ring wire used for an oil ring excellent in oil permeability. The oil ring has an opening area on the inner side of the oil ring rather than the outer side of the oil ring. An oil ring wire is disclosed in which at least one of the side walls of the oil passage hole is inclined so as to be larger.

  As described above, in the two-piece oil ring, many patents relating to the oil passage hole shape have been filed. However, the oil ring has only oil passage holes that are symmetrical in the vertical direction of the oil ring. There was nothing that could easily distinguish the vertical direction.

  By the way, a two-piece oil ring having an outer peripheral sliding surface shape that is asymmetric in the vertical direction of the piston ring, for example, an oil ring such as that disclosed in JP-A-9-144881, exhibits its function. In order to achieve this, it goes without saying that the piston needs to be assembled in the intended direction. Therefore, when assembling the piston ring to the piston, it is important to correctly assemble the piston ring in the vertical direction. If the vertical direction is assembled incorrectly, it will work differently from the original purpose, so it will not be possible to reduce the above-mentioned lubricating oil consumption, but rather deteriorate the lubricating oil consumption and increase the sliding resistance. It will be.

However, in such a conventional two-piece oil ring, the contact surface of the upper and lower rails with the cylinder is a micro-machined surface, so that the vertical direction of the two-piece oil ring can be visually determined from this sliding surface. It is very difficult. Accordingly, the piston was erroneously assembled to the piston in the vertical direction (hereinafter erroneous assembly). For this reason, in order to prevent erroneous assembly between the piston ring manufacturer and the automobile manufacturer, an arrangement such as attaching a mark to one side of the joint of the piston ring is performed to prevent the occurrence of erroneous assembly.
However, when the piston ring is transported from the piston ring manufacturer to the place where the piston ring is assembled, rust preventive oil or the like is applied, so this sign may disappear. In addition, it is necessary for the piston ring manufacturer to determine the vertical direction before attaching the mark, but for the above reason, this determination operation is not easy. For this reason, the production cost of these two-piece oil rings is high, which hinders the spread of such directional oil rings.

  That is, in the two-piece oil ring in which the oil ring outer peripheral sliding surface is provided with a sliding surface having directionality in the vertical direction, the directionality can be easily discriminated for attaching the mark 2 A piece oil ring is desirable, and a two-piece oil ring that can easily determine the direction without providing a sign is more desirable.

JP 9-144881 A JP 63-277844 A JP 2006-22903 A JP 2003-286899 A JP 2006-194272 A

 The present invention has been made in view of the above problems, and in the production of a two-piece oil ring in which the outer peripheral sliding surface shape of the upper and lower rail portions of the two-piece oil ring has a direction, An object of the present invention is to provide a two-piece oil ring wire that can be easily discriminated.

In the present invention, the following means are used to solve the above problems.
The first invention of the present application comprises an upper and lower rail (10, 11) for the purpose of oil scraping and a web (15) connecting the upper and lower rails (10, 11). The web (15) is provided with a plurality of oil passage holes (2). In the two-piece oil ring wire, the oil passage hole (2) includes an asymmetrical oil passage hole aligned in one direction in the upper and lower rail directions. is there. The second invention of the present application is the two-piece oil ring wire according to the first invention of the present application, wherein the oil passage holes having an asymmetric shape in the vertical rail direction are substantially trapezoidal or triangular.

  Here, the oil passage hole (2) is “asymmetrical shape in the vertical rail direction” means that the planar shape of the oil passage hole is the center in the vertical direction of the vertical rail when the two-piece oil ring wire is viewed from the rail sliding surface side. Means not line symmetric with respect to the line.

  In addition, the term “aligned in one direction in the upper and lower rail direction” as used herein means that the oil passage hole having an asymmetric shape such as a substantially trapezoidal shape or a substantially triangular shape moves in the direction of the wire of the two-piece oil ring wire. It means that the shape is facing the direction. For example, when the asymmetrical shape is a substantially triangular shape, it means that the bottom side is an oil passage hole that is aligned by being on one rail side of the two-piece oil ring wire.

  Furthermore, the “substantially trapezoidal shape” mentioned here has different lengths in the vertical direction, and can be determined so that the vertical direction of the figure can be distinguished, and does not mean a mathematical trapezoid. . Accordingly, the oil permeation hole includes both curved sides of the oil ring in the circumferential direction. The “substantially triangular” is formed of three sides and can distinguish the vertical direction. Note that both shapes include those in which the intersection of each side is a curve.

  FIG. 1 shows that the outer rail sliding surface shape (12) of the upper rail (10) is formed by a tapered surface whose diameter is reduced upward in the axial direction with the lower side in the axial direction as the apex from the axial center of the rail outer peripheral surface. Like the outer peripheral surface of the upper rail, the outer peripheral sliding surface (12) of the lower rail (11) is connected to the slope (14). It is a two-piece oil ring that is formed with a tapered surface that is reduced in diameter in the upper direction and is connected to the upper surface (16) of the lower rail. In such a two-piece oil ring, the piston ring must be assembled as described above when assembling the two-piece oil ring to the piston in order to exert the desired effect of the outer peripheral sliding surface shape. . However, in the conventional two-piece oil ring, the vertical direction is determined by determining the shape of the outer peripheral sliding surface (12), and is determined by using a determination device after the piston ring is completely processed. At the time of assembly at an automobile manufacturer, a sign was attached so that the vertical direction could be understood. However, this sign often disappears and could not be said to be reliable.

  Therefore, in the present invention, the two-piece oil ring has an asymmetric shape in the vertical direction at the stage of drilling the wire for the two-piece oil ring so that the vertical direction can be determined by looking at the shape of the oil passage hole from the outer rail side. When an oil passage hole is provided and a directional process is performed on the outer peripheral sliding surface of the upper and lower rails, machining is performed in accordance with a predetermined direction based on the shape of the oil passage hole. If processed in this way, even if the vertical direction becomes uneven in the subsequent process, the final direction can be easily aligned visually or with an automatic discriminator, and can be assembled even when the oil ring is assembled to the piston. Since it can be attached to the machine without making a mistake in the vertical direction, it is possible to eliminate misassembly.

  Hereinafter, the wire material for a two-piece oil ring for an internal combustion engine of the present invention will be specifically described with reference to the drawings.

  FIG. 2 is a plan view of the two-piece oil ring wire (a) and (b) according to the present invention and the conventional two-piece oil ring (c) wire as viewed from the rail side which is the outer peripheral surface side of the piston ring. A plurality of oil passage holes are provided in the web (15) sandwiched between the upper and lower rails (10, 11). The wire for a two-piece oil ring in FIG. 2 (a) has a substantially trapezoidal oil passage hole (2a) in which the oil passage hole is one form of an asymmetric shape in the upper and lower rail directions and one form symmetrical to the upper and lower rail directions. It consists of a substantially oval oil passage hole (2c). The asymmetrical substantially trapezoidal oil passage hole (2a) includes a long straight line (3) on the upper rail side, a short straight line (4) on the lower rail side, a left side (5) connecting the long straight line and the left end of the short straight line. ) And the right side (6) connecting the long straight line and the right end of the short straight line, and aligned in one direction with the upper rail side as the long side. In this example, one substantially trapezoidal oil passage hole and one substantially oval oil passage hole are formed repeatedly.

  Here, FIG. 2 (a) is an embodiment of the present invention, and the present invention is not limited to this, and as an asymmetric shape in the vertical rail direction, in addition to the substantially trapezoidal shape, the triangle (2b), A parallelogram or the like can be used. In addition, as a shape symmetric with respect to the upper and lower rails, a circle, an ellipse, an ellipse, a square, a rectangle, or the like can be used. In addition, the oil passage holes having an asymmetric shape in the upper and lower rail directions are repeatedly formed at intervals of five from the oil passage holes 1 having a symmetrical shape in the upper and lower rail directions. In addition, when it shape | molds to a piston ring, since the piston ring circumferential direction both ends may be applied to the said oil passage hole, it is not this limitation.

  Next, a method for producing a two-piece oil ring wire according to the present invention will be described. The two-piece oil ring of the present invention is a deformed wire manufactured by a cold drawing method or a hot working method of a roll die, and the outer peripheral sliding surface shape of the upper and lower rails (10, 11) is an asymmetric two-piece oil. It is preferably used for rings, and it is desirable to reduce the amount of processing by forming the shape of both rail outer peripheral sliding surfaces of the wire rod to a shape close to the desired directionality. Can be processed with reference to the directionality of the oil passage hole of the present invention at the time of processing the outer peripheral sliding surface, and it is not necessary to use such a wire. Although it is considered that there is a desirable relationship between the direction of the oil passage hole shape and the direction of the outer peripheral sliding surface shape, as described above, the outer peripheral sliding surface machining should be performed according to the direction of the oil passage hole. It is not limited here.

  First, after removing the surface flaws of the coil material that has been annealed after hot rolling the steel material, the wire diameter matches the oil ring body size by warm drawing, and a rectangular wire having a rectangular cross section is formed by a four-way roll. This is subjected to continuous deformed roll processing with a hot and cold perforated roll die to obtain a deformed wire for a two-piece oil ring of the present invention. The oil passage hole is generally formed by a punching punch. Thereafter, quenching and tempering are performed to obtain a two-piece oil ring wire. In punching and punching, punching is performed with a plurality of arranged punching punches, and a plurality of oil passage holes are formed at the same time. Therefore, if a part or all of the punch is a punch through which an asymmetric shape is punched in the vertical direction, and the other punch is a punch through which an oil passage hole that is symmetrical in the vertical direction is punched, the asymmetrical oil passage hole and the symmetrical passage are provided. A wire rod in which oil holes are regularly and periodically arranged can be obtained. In this way, when a wire for a two-piece oil ring is made, even if it is formed into a two-piece oil ring, it will appear in one field of view repeatedly, excluding both ends in a pattern with the formed asymmetric oil passage holes in the vertical direction. The vertical direction of the two-piece oil ring can be easily confirmed.

  The two-piece oil ring wire of the present invention is a wear-resistant material used by forming a mild steel wire, gas nitrided layer, salt bath nitrided layer, etc. to be used by providing a hard chromium plating film or ion plating film on the outer peripheral sliding surface Since it is formed from a material of high alloy steel such as martensitic stainless steel, which has a lot of improvement in heat resistance and heat resistance, punching has been carried out by punching, but recently, as oil rings have become thinner, Since the oil holes have become finer, in addition to punching with a punching punch, the formation of oil passage holes using a laser, an electron beam, or the like has come to be performed.

  In the second invention of the present application, the shape of the oil passage hole which is asymmetric in the vertical direction is substantially trapezoidal or triangular. The substantially trapezoidal oil passage hole is preferable as an asymmetric oil passage hole because the oil passage performance and the strength in the vertical direction are less deteriorated than the conventional oval or square oil passage hole. If the substantially trapezoidal corners and the sides in the axial direction are formed in an arc shape, the change in the cross-sectional moment is reduced, which is more preferable. When the triangular shape is used, the visibility is improved and the risk of incorrect assembly can be further reduced. In the case of a triangular shape, a triangle having a long bottom is desirable from the viewpoint of punch life in drilling, ring strength, and the like.

  In addition, this invention is not limited to the said embodiment. Any device that has substantially the same configuration as the technical idea described in the claims of the present invention and that exhibits the same effect is included in the technical scope of the present invention. .

The present invention will be described more specifically with reference to the following examples and comparative examples.
[Example 1]
The material is C: 0.85, Si: 0.35, Mn: 0.30, P: 0.03, S: 0.02, Cr: 18.0, Mo: 1.25, V: 0.10 , Fe: Remaining (mass%) (JIS SUS440B equivalent) steel round wire was annealed after hot rolling, and after removing surface flaws of the coil material, it was φ5 which was in the oil ring body size by warm drawing 5 mm. This is converted into a rectangular wire having a rectangular cross section by a four-way roll, and subjected to continuous deformed roll processing by a hot and cold perforated roll die to obtain a deformed wire for a two-piece oil ring. The oil passage hole was formed by a punching punch. The punching punch was made by punching 5 holes at the same time. The punch in the center of the punching punch was punched out in a substantially trapezoidal shape, and the others were punched out in a conventional oval shape. Thereafter, quenching and tempering were performed to obtain a two-piece oil ring wire having a vertical width of 1.5 mm and an inner and outer diameter thickness of 1.5 mm. The shape of the oil passage hole is a substantially trapezoid and an ellipse, and two substantially trapezoids are arranged in a ratio of three ellipses to two.

  This wire is molded by a coiling device for piston ring so that the outer diameter becomes 75.0 mm, and the coiled one is grinded into a shape that approximates the outer peripheral sliding surface to some extent, cut, and then molded by heat treatment The stress at the time was removed, and a gas nitride layer was formed as a surface treatment. After that, the outer peripheral sliding surface of the rail is processed with a grinding wheel so that the shape of the outer peripheral sliding surface of the rail is formed as an asymmetrical shape with the lower side of the piston axial direction from the center of the piston axis as the apex. Similarly to the outer rail of the upper rail, the outer sliding surface is formed in an asymmetrical shape with the lower axis of the lower rail as a vertex from the lower piston axis direction, and is configured to be connected to the lower rail lower surface. A suitable outer peripheral sliding surface shape was created. Next, a two-piece oil ring main body was manufactured in a process of preparing a ring joint and processing the side surface so that the height h1 of the main body was 1.5 mm.

  The outer peripheral sliding surface was processed by aligning the direction of the two-piece oil ring main body so that the long side of the substantially trapezoidal oil passage hole was on top, and performing profile polishing one by one. At this time, in the coiling state, it was necessary to match the direction in which the grindstone was processed to a shape approximated to the outer peripheral sliding surface, but it was visually performed using the asymmetric oil passage hole of the two-piece oil ring as a mark. Discrimination was easy, and there was no wrong direction. Next, after all processing was completed, in the step of marking, the piston ring vertical direction was also determined using the asymmetric oil passage hole as a mark, but the piston ring vertical direction was easily determined visually.

[Example 2]
Implementation of steel round wire with material of C: 0.75, Si: 0.25, Mn: 0.75, P: 0.01, S: 0.02, Fe: remainder (mass%) (JIS SWRH77B) By processing similar to Example 1, a deformed wire for a two-piece oil ring was obtained. Thereafter, oil passage holes were formed. The oil passage hole has an asymmetrical shape of a substantially triangular shape and a symmetrical shape of an elliptical shape. Thereafter, quenching and tempering were performed to obtain a two-piece oil ring wire having a vertical width of 2.0 mm and an inner and outer diameter thickness of 2.0 mm. The oil passage holes are arranged in a ratio of approximately one triangle and four ellipses. This wire was molded with a piston ring coiling device so that the outer diameter was 83.0 mm, cut, and then subjected to heat treatment to remove stress during molding.

  The outer periphery of the two-piece oil ring after the heat treatment has been processed, and the shape of the outer peripheral sliding surface of the rail is formed from an asymmetrical shape with the lower end in the piston axial direction from the center of the piston axial direction connected to the upper surface of the upper rail. Like the outer rail of the upper rail, the outer rail sliding surface of the lower rail is formed in an asymmetric shape with the lower axis of the lower rail as the apex from the piston axis direction of the lower rail, and is connected to the lower rail lower surface. An outer peripheral sliding surface shape having a directivity is created. At this time, the direction of the outer peripheral surface processing was performed using the apex of the triangle as a mark.

Thereafter, an ion plating film is formed as a surface treatment, and the perimeter of the outer peripheral sliding surface is confirmed by lapping with diamond abrasive grains. Further, the ring abutment is prepared, and the height h1 of the main body becomes 2.0 mm. Then, the side surface was processed, and finally, a phosphate film was applied for rust prevention to complete a two-piece oil ring body.
Finally, for shipping purposes, about 100 two-piece oil rings are aligned so that the apex of the triangle is in one direction for the purpose of marking the outer peripheral sliding surface, and the outer peripheral surface shape is automatically identified using laser light. As a result of checking with a machine, there was no one with different directions.

Sectional drawing of a two-piece oil ring whose upper and lower rail outer peripheral sliding surface shape is asymmetric in the vertical direction. It is the schematic plan view which looked at the 2 piece oil ring wire of this invention and the conventional 2 piece oil ring wire from the outer periphery rail side, (a) (b) is this invention product, (c) is a conventional product.

Explanation of symbols

1-2 piece oil ring body 2-oil passage hole 2 a-substantially trapezoidal oil passage hole 3-upper side 4-lower side 5-left side 6-right side 10-upper rail 11-lower rail 12 -Rail outer peripheral sliding surface 13-Upper rail lower slope 14-Upper rail upper slope 15-Web 16-Lower rail lower slope 17-Lower rail lower slope 18-Coil expander

Claims (2)

Connecting it with top and bottom rails (10, 11) becomes from the web (15), wherein the web (15), in the two-piece oil ring for wire plurality of oil passing holes (2) are provided, wherein The oil passage hole includes a substantially trapezoidal oil passage hole having an upper rail side as a long side, and a two-piece oil ring wire. A two-piece oil ring comprising an upper and lower rail (10, 11) and a web (15) connecting the upper and lower rails (10, 11). The web (15) has an oil ring body provided with a plurality of oil passage holes (2). The oil passage hole includes a substantially trapezoidal oil passage hole having a long side on the upper rail side .

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