JP2007263068A - Piston abrasion resistant ring - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a structure easily joining an abrasion resistant ring body and a molding, hardly generating joining failure, and efficiently cooling the abrasion resistant ring body. <P>SOLUTION: This piston abrasion resistant ring 1 used as an insert when molding a piston for an engine, is composed of: a ring-shaped body part 20 which has at least one piston ring groove 200 into a peripheral surface or has a peripheral surface part 201 where the piston ring groove 200 is formed, and an inner peripheral surface 202 facing the peripheral surface part 201 and partitioning a fluid passage 4 for cooling fluid, the abrasion resistant ring body 2; and a cooling pipe part 3 composed of a ring-shaped short diameter side wall part 30 which abuts on the side surface on the axial other end side of a ring-shaped protruding wall 21 and is integrally fixed to the abrasion resistant ring body 2, a ring-shaped long diameter side wall part 31 which abuts on the side surface on the other end side of the abrasion resistant ring body 2 and is integrally fixed to the abrasion resistant ring body 2, and a ring-shaped bottom wall part 32 forming a cooling groove opposed to the inner peripheral surface 202 of the ring-shaped body part 20. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a wear-resistant ring that is cast into an engine piston and holds a piston ring.

  In recent years, for the purpose of reducing the weight and improving heat dissipation, an engine made of an aluminum alloy is becoming popular, and a piston is also made of an aluminum alloy. On the other hand, since the engine tends to have lower fuel consumption and higher output, it becomes a higher-temperature combustion environment, and the piston ring is required to have high wear resistance, so a high-rigidity piston ring is used. . For this reason, since the piston ring groove is in contact with the piston ring having high hardness violently, there is a possibility that the piston ring groove may be bent or deformed in an aluminum alloy. In particular, since the combustion pressure directly acts on the top ring of a diesel engine having a high combustion temperature, the impact of the piston ring is repeated in the top ring groove, and the wear is likely to occur. When the top ring groove is worn, gas leakage and oil leakage occur, and the engine also decreases in output.

  In order to improve this, a wear-resistant ring made of a cast resist made of a resist that is harder at high temperatures than the aluminum alloy of the piston body is cast near the top ring groove of the piston made of aluminum alloy. Various pistons with rings have been proposed.

  Moreover, since the temperature of a piston top part or the top ring groove part of the vicinity becomes high temperature by the high temperature combustion environment of an engine, it is necessary to reduce heat. Therefore, conventionally, a structure in which an annular cooling cavity for circulating a cooling medium (cooling fluid) in the vicinity of the wear-resistant ring is arranged and the wear-resistant ring is directly cooled has been studied.

  For example, in Patent Document 1, the piston has a substantially U-shaped cross section in the axial direction of the piston, and a joint surface that joins two end portions of the molded body on the inner peripheral surface side of the piston. A mechanism for cooling the piston ring groove by joining a wear-resistant ring body having a ring groove and forming a cooling medium passage through which the cooling medium circulates has been proposed. However, this molded body is usually manufactured by roll forming or the like of a metal plate, so that it is difficult to manufacture with high accuracy due to a spring back or the like. As shown in FIG. And the inner peripheral surface 202 of the wear-resistant ring body 2 cannot be manufactured so as to fit closely, and manufacturing defects tend to occur. Even if the poorly molded body and the wear-resistant ring body are joined, either end of the molded body cannot contact the inner peripheral surface of the wear-resistant ring body, resulting in poor bonding and a gap in the cooling medium passage. As a result, the cooling medium may leak out.

  Patent Document 2 proposes an invention in which the wear-resistant ring main body and the molded body can be joined even if the molded body is not manufactured with high precision. As shown in FIG. 11, the inner peripheral surface side of the wear-resistant ring body 2 has a substantially U-shaped groove 23 in the axial cross section of the piston, and both end portions of the molded body 3 whose axial cross section is substantially U-shaped. The cooling medium passage 4 is formed by being fitted into the groove. Even if the lengths of both ends of the molded body are not made with high accuracy, they are fitted into the wear-resistant ring main body, so that there is no gap in the cooling medium passage.

Further, in the invention of Patent Document 3, as in Patent Document 2, the wear-resistant ring body has a substantially U-shaped groove (stepped portion) in the axial cross section of the piston on the inner peripheral surface side, and the molded body has an outer periphery. The upper and lower ends in the axial direction on the surface side have notches, and these notches are fitted into the grooves on the inner peripheral surface of the wear-resistant ring. Since the molded body has a ring-shaped cavity inside and circulates the cooling medium in the cavity, even if a gap is formed due to poor bonding between the wear-resistant ring and the molded body, the cooling medium passage is not affected.
JP-A-5-231539 Japanese Patent Laid-Open No. 5-240347 JP 2003-90432 A

  The inventions of Patent Document 2 and Patent Document 3 are joined by fitting an end portion of another member into a member having a substantially U shape. Compared to Patent Document 1, there is no gap in the joining, and the invention of Patent Document 2 does not leak the cooling medium, and the invention of Patent Document 3 does not easily peel the molded body having the cooling medium passage from the wear-resistant ring body.

  However, for example, when the molded body is fitted into the wear-resistant ring main body, when viewed from the vertical direction of the axial direction of the piston, both the fitted member and the fitted member are in a ring shape. It can be imagined that it is extremely difficult to fit a ring-shaped member inside the side. In other words, since the outer diameter of the molded body is larger than the inner diameter of the wear-resistant ring body, the inner diameter of the wear-resistant ring body is expanded or the outer diameter of the molded body is not temporarily reduced. It seems that it is difficult to match, and if you change the diameter temporarily, it will take extra effort.

  Further, in the invention of the above-mentioned Patent Document 3, since the cooling medium passage is inside the molded body, there is a wall on the outer peripheral side of the molded body and a wall on the inner peripheral surface side of the wear-resistant ring body. There is a distance to the main body, and it seems that the cooling efficiency is poor for cooling the wear-resistant ring main body.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a structure in which the wear-resistant ring main body and the molded body can be easily joined and hardly cause poor bonding, and the wear-resistant ring main body is efficiently cooled. .

  The piston wear-resistant ring of the present invention is a piston wear-resistant ring used as an insert during casting of the piston to form a piston ring groove of an engine piston, and has at least one piston ring groove on an outer peripheral surface. Or a ring-shaped main body portion having an outer peripheral surface portion in which the piston ring groove is formed and an inner peripheral surface facing the outer peripheral surface portion and defining a fluid passage for cooling fluid, and the inner peripheral surface of the ring-shaped main body portion. A wear-resistant ring body formed of a ring-shaped projecting wall integrally formed on one end side in the axial direction and projecting further in the axial direction than the inner peripheral surface; and a side surface on the other end side in the axial direction of the ring-shaped projecting wall A ring-shaped short-diameter side wall portion that comes into contact with the wear-resistant ring body and is integrally fixed to the wear-resistant ring body. Shaped long diameter side wall, the short diameter side wall and the A cooling pipe portion comprising a ring-shaped bottom wall portion integrally connected to the radial side wall portion and opened to the outer peripheral side to form a cooling groove facing the inner peripheral surface of the ring-shaped main body portion. Features.

  The piston wear-resistant ring of the present invention is arranged along the peripheral wall of the cylindrical piston, and the wear-resistant ring main body and the cooling pipe part have a ring shape in general, and the wear-resistant ring main body is located on the outer peripheral side, A cooling pipe part is located in the inner peripheral side of an axial direction from a wear-resistant ring main part. This wear-resistant ring body has a ring-shaped protruding wall with a part of the inner peripheral surface protruding in the axial direction, abuts against the ring-shaped short-diameter side wall of the cooling pipe, and the ring-shaped long-diameter side wall of the cooling pipe The portion comes into contact with the other end of the wear-resistant ring body. A fluid passage for the cooling fluid is formed by the inner peripheral surface of the wear-resistant ring body, the short-diameter side wall portion, the long-diameter side wall portion, and the ring-shaped low wall portion of the cooling pipe portion.

  In the piston wear-resistant ring of the present invention, in the axial direction of the piston, the cooling pipe portion and the wear-resistant ring main body are simply fitted into the short diameter side wall portion side of the cooling pipe portion from the opposite direction of the ring-shaped protruding wall of the wear-resistant ring main body. And can be joined. Temporarily, the diameter can be easily joined without increasing the diameter of the wear-resistant ring main body side or the diameter of the cooling pipe portion side, and a fluid passage for cooling fluid can be formed without a gap. Further, since the cooling fluid is in direct contact with the inner peripheral surface side of the wear-resistant ring body, the cooling efficiency of the piston wear-resistant ring is good.

  The wear-resistant ring body used in the piston wear-resistant ring of the present invention preferably has a ring-shaped notch on which the long-diameter side wall portion of the cooling pipe portion abuts and is fixed to the side surface on the other end side. By this notch, the long-diameter side wall portion can be fitted into the notch, and the wear-resistant ring body and the cooling pipe portion can be more stably fixed.

  According to the piston wear-resistant ring of the present invention, the diameter of the wear-resistant ring main body is not increased or the diameter of the cooling pipe portion is not narrowed, and the wear-resistant ring main body and the cooling pipe portion are simply joined by fitting in the axial direction of the piston. can do.

  Further, since the cooling fluid circulates directly on the inner peripheral surface side of the wear-resistant ring body, the cooling efficiency of the wear-resistant ring body is good.

  Hereinafter, the present invention will be specifically described with reference to examples.

Example 1
An axial sectional view of the piston wear-resistant ring 1 of the first embodiment is shown in FIG. The piston wear-resistant ring 1 includes a ring-shaped wear-resistant ring main body 2 positioned on the outer peripheral side and a ring-shaped cooling pipe portion (molded body) 3 positioned on the inner peripheral side of the wear-resistant ring main body 2.

  The wear-resistant ring main body 2 has a ring-shaped main body portion 20 having an outer peripheral surface portion 201 in which a piston ring groove 200 is formed on an outer peripheral surface and an inner peripheral surface 202 that faces away from the outer peripheral surface portion 201 and defines the fluid passage 4 for cooling fluid. The ring-shaped protruding wall 21 projecting in the axial direction from the inner peripheral surface 202 integrally formed on the lower end side in the axial direction of the inner peripheral surface 202 of the ring-shaped main body 20, and the axial direction of the inner peripheral surface 202 It consists of a ring-shaped notch 22 on the upper end side. The piston ring groove 200 that opens to the outer peripheral surface 201 side is cast into an engine piston, and is cut off after molding. The ring-shaped projecting wall 21 has a rectangular cross section protruding in the axial direction side, and the ring-shaped notch 22 has a rectangular cross section cut out in the radial direction side.

  The cooling pipe portion 3 includes a short-diameter side wall portion 30 that contacts the ring-shaped protruding wall 21 of the wear-resistant ring body 2, a long-diameter side wall portion 31 that contacts the ring-shaped notch 22, a short-diameter side wall portion 30, and a long-diameter side wall portion 31. And the ring-shaped bottom wall portion 32 that forms a cooling groove that faces the inner peripheral surface 202 of the ring-shaped main body portion 20 and opens to the outer peripheral surface side is substantially U-shaped. .

  The wear-resistant ring body 2 and the cooling pipe portion 3 are joined to the wear-resistant ring body 2 by fitting the cooling pipe portion 3 downward from the upper side in the axial direction. The first joint surface 210 on the upper side in the axial direction of the ring-shaped protruding wall 21 and the surface on the lower side in the axial direction of the short-diameter side wall portion 30 come into contact with each other. The fluid passage 4 through which the cooling fluid circulates is formed without a gap when the side surface 31 is in contact with the lower surface in the axial direction.

  The wear-resistant ring body 2 and the cooling pipe portion 3 are made of a niresist material that is harder than an aluminum alloy and wear-resistant at high temperatures. Since the cooling pipe part 3 is manufactured by roll forming or the like of a metal plate, it tends to cause a forming error and is difficult to manufacture with high accuracy. For example, as shown in FIG. 2, the case where the radial direction length of the long diameter side wall part 32 is insufficient is considered. However, in the piston wear-resistant ring 1 according to the first embodiment, if the lower surface in the axial direction of the long-diameter side wall portion 32 can contact the second joint surface 220 of the ring-shaped notch 22, the piston wear-resistant ring can be connected from the fluid passage 4. The wear-resistant ring main body 2 and the cooling pipe portion 3 can be joined together without forming a gap through which the cooling fluid leaks to the outside. That is, in the radial direction of the piston, even if the long-diameter side wall portion 32 and the short-diameter side wall portion 31 are short, the lower side of the long-diameter side wall portion 32, the second joint surface 220 of the ring-shaped notch 22, and the short-diameter side wall If the lower side of the portion 31 and the first joint surface 210 of the ring-shaped protruding wall 21 abut, the fluid passage 4 is formed without any gap. Therefore, the manufacturing accuracy to the extent that the cooling pipe portion 3 must be fitted into the wear-resistant ring body 2 is not required, and there may be loose fitting in the radial direction (axial direction) of the piston.

  FIG. 3 is an axial sectional view of a part of the piston 5 for an engine in which the piston wear-resistant ring 1 of the first embodiment is cast. The piston wear-resistant ring 1 of the first embodiment is disposed at the position of the top ring of the engine piston 5. After the piston wear ring 1 is cast and molded in an engine piston, the piston ring groove 200 is scraped off. The cooling fluid that circulates in the fluid passage 4 has a pipe that communicates from below the engine piston 5 to the fluid passage 4 and is supplied through this pipe.

  In the piston wear-resistant ring 1 of the first embodiment, the wear-resistant ring body 2 and the cooling pipe portion 3 can be simply joined simply by fitting in the axial direction of the piston, and in addition, the fluid passage 4 through which the cooling fluid circulates. Is formed without gaps. Since the cooling fluid circulates in direct contact with the inner peripheral surface 202 of the wear-resistant ring body 2, the cooling efficiency of the wear-resistant ring body 2 is good.

(Example 2)
The piston wear-resistant ring 1 of the second embodiment has the same configuration as that of the first embodiment except that the shape of the cooling pipe portion 3 of the piston wear-resistant ring 1 of the first embodiment is different. Therefore, members that are not particularly mentioned in the embodiments described below are the same as those in the first embodiment, and detailed description thereof is omitted.

  FIG. 4 shows an axial sectional view of the piston wear-resistant ring 1 of the second embodiment, and FIG. 5 shows an axial sectional view of the piston wear-resistant ring 1 of the second embodiment cast into the engine piston 5.

  In the cooling pipe portion 3 used in the piston wear-resistant ring 1 of the second embodiment, the ring-shaped bottom wall portion 32 has a depression in the radial direction at the central portion in the axial direction, and the axial cross section has a sigma shape. Thereby, the heat receiving area of the cooling pipe part 3 increases, and the temperature of the top part of the piston 5 for engines can be reduced.

(Example 3)
The piston wear-resistant ring 1 of the third embodiment is the same as that of the second embodiment except that the shape of the inner peripheral surface 202 of the wear-resistant ring body 2 of the piston wear-resistant ring 1 of the second embodiment is different. is there. Therefore, members that are not particularly mentioned in the embodiments described below are the same members as those in the second embodiment, and detailed description thereof is omitted.

  An axial sectional view of the piston wear-resistant ring 1 of the third embodiment is shown in FIG.

  The wear resistant ring 2 used in the piston wear resistant ring 1 of Example 3 has fine irregularities formed on the surface of the inner peripheral surface 202 by a water jet or the like. Thereby, the oil retaining property of the inner peripheral surface 202 is improved, and the temperature of the wear-resistant ring body 2 can be efficiently reduced.

Example 4
The piston wear-resistant ring 1 of the fourth embodiment has the same configuration as that of the second embodiment except that the shape of the wear-resistant ring body 2 of the piston wear-resistant ring 1 of the second embodiment is different. Therefore, members that are not particularly mentioned in the embodiments described below are the same members as those in the second embodiment, and detailed description thereof is omitted.

  FIG. 7 shows an axial sectional view of the piston wear-resistant ring 1 of the fourth embodiment.

  In the wear-resistant ring 2 used in the piston wear-resistant ring 1 of the fourth embodiment, the upper surface 203 and the lower surface 204 in the axial direction of the ring-shaped main body 20 are processed to be uneven. Thereby, not only the cooling pipe part 3 but the heat receiving area of the wear-resistant ring body 2 can be increased, and the temperature of the top part of the engine piston 5 can be reduced.

(Example 5)
The piston wear-resistant ring 1 of the fifth embodiment has a shape in which the wear-resistant ring main body 2 of the piston wear-resistant ring 1 of the first embodiment is stacked in two stages in the axial direction, and the cooling pipe portion 3 is also joined to the two-stage set of the wear-resistant ring main body 2. The rest of the configuration is the same as that of the first embodiment. Therefore, members that are not particularly mentioned in the embodiments described below are the same as those in the first embodiment, and detailed description thereof is omitted.

  FIG. 8 shows an axial sectional view of the piston wear-resistant ring 1 according to the fifth embodiment cast into the engine piston 5.

  In the piston wear-resistant ring 1 of Example 5, two wear-resistant ring main bodies 2 are connected in the axial direction, the lower wear-resistant ring main body 2 has a ring-shaped protruding wall 21 at the lower end, and the upper wear-resistant ring main body 2 is at the upper end. A ring-shaped notch 22 is provided in the part, and the cooling pipe part 3 has a shape in which a ring-shaped bottom wall part 32 is extended in the axial direction. As a result, the engine piston 5 can be cooled from the top ring to the vicinity of the second ring.

(Example 6)
The piston wear-resistant ring 1 of the sixth embodiment is different from that of the first embodiment except for the shape of a part of the wear-resistant ring body 2 of the piston wear-resistant ring 1 of the first embodiment and a part of the cooling pipe portion 3. The configuration is the same. Therefore, members that are not particularly mentioned in the embodiments described below are the same as those in the first embodiment, and detailed description thereof is omitted.

  FIG. 9 shows an axial sectional view of the piston wear-resistant ring 1 of the sixth embodiment.

  In the wear-resistant ring body 2 used in the piston wear-resistant ring 1 of Example 6, the ring-shaped protruding wall 21 has an axial width that decreases in the axial direction, and the first joint surface 210 has an oblique shape. The ring-shaped notch 22 at the upper end of the inner peripheral surface 202 is not provided. The cooling pipe portion 3 has a short side wall portion 30 whose axial width is reduced in the radial direction and whose lower surface is oblique. The first joint surface 210 of the ring-shaped projecting wall 21 and the lower surface of the short-diameter side wall portion 30 are in contact with each other, and the long-diameter side wall portion 31 and the axial upper surface 203 of the ring body portion 20 are in contact with each other. .

  In the piston wear-resistant ring 1 according to the sixth embodiment, the first joint surface 210 of the ring-shaped protruding wall 21 and the lower surface of the short-diameter side wall portion 30 are slidably in contact with each other, and therefore, in the axial direction (radial direction) and axial direction. The cooling pipe part 3 has a margin for joining with the wear-resistant ring body 2. That is, even if the cooling pipe portion 3 cannot be manufactured with high accuracy in the axial center direction and the axial direction, it can come into contact with the slide shape, and as a result, the fluid passage 4 can be formed without a gap.

  As mentioned above, although the suitable Example of this invention was described, this invention is not limited to the said Example. For example, the wear-resistant ring body 2 and the cooling pipe portion 3 are not limited to Ni-resist materials, but may be any material that is harder than aluminum alloy and resistant to high temperatures.

1 is an axial cross-sectional view of a piston wear-resistant ring 1 of Embodiment 1. FIG. 1 is an axial cross-sectional view of a piston wear-resistant ring 1 of Embodiment 1. FIG. FIG. 3 is a sectional view in the axial direction of a part of an engine piston 5 in which a piston wear-resistant ring 1 of Example 1 is cast. FIG. 4 is an axial cross-sectional view of a piston wear-resistant ring 1 according to a second embodiment. FIG. 5 is a cross-sectional view in the axial direction of a part of an engine piston 5 in which a piston wear-resistant ring 1 of Example 2 is cast. It is an axial sectional view of the piston wear-resistant ring 1 of the third embodiment. It is an axial sectional view of the piston wear-resistant ring 1 of the fourth embodiment. It is an axial sectional view of a part of an engine piston 5 in which a piston wear ring 1 of Example 5 is cast. It is an axial sectional view of the piston wear-resistant ring 1 of the sixth embodiment. Prior art piston wear ring Prior art piston wear ring

Explanation of symbols

1: Piston wear-resistant ring 2: Wear-resistant ring main body 3: Cooling pipe part 4: Fluid passage 5: Engine piston 20: Ring-shaped main body part 21: Ring-shaped protruding wall 22: Ring-shaped notch 23: Groove 30: Short-diameter side wall Portion 31: Long side wall portion 32: Ring-shaped bottom wall portion 200: Piston ring groove 201: Outer peripheral surface portion 202: Inner peripheral surface 203: Upper surface 204: Lower surface 210: First joint surface 220: Second joint surface

Claims (2)

A piston wear ring used as an insert during casting of the piston to form a piston ring groove of an engine piston,
A ring-shaped main body having at least one piston ring groove on the outer peripheral surface or having an outer peripheral surface portion on which the piston ring groove is formed and an inner peripheral surface facing away from the outer peripheral surface portion and defining a fluid passage for cooling fluid And a wear-resistant ring body formed of a ring-shaped protruding wall that is integrally formed on one end side in the axial direction of the inner peripheral surface of the ring-shaped main body portion and protrudes further in the axial direction than the inner peripheral surface;
A ring-shaped short-diameter side wall portion that is in contact with the side surface on the other end side in the axial direction of the ring-shaped protruding wall and fixed integrally to the wear-resistant ring body, and a side surface on the other end side of the wear-resistant ring body A ring-shaped long-diameter side wall portion that is integrally fixed to the wear-resistant ring main body, and the short-diameter side wall portion and the long-diameter side wall portion are integrally connected to open to the outer peripheral side, and the ring-shaped main body portion A cooling pipe part comprising a ring-shaped bottom wall part that forms a cooling groove facing the inner peripheral surface;
Piston wear-resistant ring characterized by comprising   2. The piston wear-resistant ring according to claim 1, wherein the wear-resistant ring body has a ring-shaped notch with which the long-diameter side wall portion of the cooling pipe portion abuts and is fixed to a side surface on the other end side.

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