JP2005042626A - Method of manufacturing friction-proof ring with cooling cavity - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a friction-proof ring with a cooling cavity having a high cooling capacity at a low facility cost and few manufacturing processes. <P>SOLUTION: The method for manufacturing the friction-proof ring with the cooling cavity includes setting of an annular metal tube 8 having substantially the same outer diameter as an inner diameter of an annular friction-proof ring 3 at an inner peripheral side of the annular friction-proof ring 3, bringing a circumferential surface of a taper shape punch 9 of circular cross section into contact with an inner peripheral side of the metal tube 8, loading a load to a punch 10, relatively moving the punch 10 in an axial direction of a piston to the friction-proof ring 3, and press bonding the friction-proof ring 3 to the metal tube 8. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method for manufacturing a wear-resistant ring in which a piston ring is incorporated by being cast into a piston body of a piston for an internal combustion engine, and in particular, an annular cooling cavity for refluxing cooling oil for cooling the piston is provided on the inner peripheral side. The present invention relates to a method for manufacturing an attached wear-resistant ring.

  In recent years, the engine output has been increased, and the heat load applied to the piston by the thermal energy due to compression / explosion has increased. In particular, the piston head part and ring land part become hot, and in addition, soot is generated and adhered due to carbonization and combustion of engine lubricating oil, so that the deterioration of the function due to wear of the piston ring provided in the ring land part is accelerated. Oil consumption is increasing.

  In order to deal with such problems, conventionally, a ring ring portion of the piston is cast with a wear-resistant ring made of cast nizirest material or iron-based sintered material having high wear resistance at high temperatures. An annular cooling cavity for recirculating cooling oil for cooling the piston is provided on the inner peripheral side.

As a method of providing this cooling cavity, (1) a method of providing a cooling cavity with a salt core which is a kind of soluble core (see, for example, Patent Document 1), and (2) an annular ring on the inner peripheral side of the wear-resistant ring A method of joining a U-shaped metal plate by brazing or welding (see, for example, Patent Document 2), (3) A method of joining an annular metal pipe to the inner peripheral side of a wear-resistant ring by sintering fitting ( For example, see Patent Document 3).
Japanese Utility Model Publication No. 58-52346 JP-A-5-231539 JP 2001-107802 A

  However, the method of providing a cooling cavity with a salt core which is a kind of the soluble core of (1) requires a step of eluting the salt core with water after casting the piston, which increases the number of manufacturing steps. is there. Further, when the cooling cavity is provided by the salt core, the cooling cavity is provided at a position separated from the wear-resistant ring by a certain amount, so that there is a problem that the cooling capacity is reduced.

  Further, in the method (2) in which the annular metal plate having a U-shaped cross section is joined to the inner peripheral side of the wear-resistant ring by brazing or welding, the strength of the piston head portion 101 is ensured as shown in FIG. Therefore, it is necessary to make the distance between the combustion chamber wall surface 102 and the cooling cavity 103 a certain distance or more. Therefore, since the length of the cooling cavity 103 in the radial direction of the piston cannot be secured, there is a problem that the volume of the cooling cavity 103 is reduced and the cooling capacity is reduced. In addition, in order to obtain a ring-shaped and U-shaped metal plate, it is necessary to perform a narrowing process on the U-shaped metal plate after it is welded in a ring shape, resulting in a problem that the equipment cost increases and the manufacturing process increases. . Further, even in the method of joining the annular metal pipe (3) to the inner peripheral side of the wear-resistant ring by sintering fitting, it takes a long time for the sintering process, and the time required for the entire manufacturing becomes longer. There's a problem.

  Then, this invention makes it a subject to provide the method of manufacturing a wear-resistant ring with a cooling cavity with high cooling capability with low equipment cost and few manufacturing processes in view of said problem.

  In order to solve the above-mentioned problems, the invention according to claim 1 is a wear-resistant ring that is cast into a piston body and in which a piston ring is incorporated, and an annular cooling cavity for returning cooling oil is attached to the inner peripheral side. In the manufacturing method of the wear-resistant ring, an annular metal tube having an outer diameter substantially the same as the inner diameter of the wear-resistant ring is set on the inner circumference side of the annular wear-resistant ring, and the circumferential surface of the punch having a circular cross section and a tapered shape is provided on the metal tube. The wear-resistant ring and the metal tube are made to contact from the inner peripheral side of the steel plate and are moved relative to the wear-resistant ring in the axial direction of the piston perpendicular to both the circumferential direction and the radial direction of the wear-resistant ring. And a cooling cavity is constituted by the pressure-bonded metal tube.

  The invention according to claim 2 is the method of manufacturing the wear-resistant ring with the cooling cavity according to claim 1, wherein the wear-resistant ring is set, and the wear-resistant ring is displaced in one direction among the radial displacement of the wear-resistant ring and the piston axial direction. A wear-resistant ring set portion that regulates the displacement of the wear-resistant ring, and a metal tube set portion that sets a metal tube on the inner peripheral side of the wear-resistant ring set portion and regulates displacement in one direction of the piston axial direction. A wear ring and a metal tube are set on a setting jig, and the punch is relatively moved in one direction from the other direction side in the piston axial direction.

  The invention described in claim 3 is the method of manufacturing the wear-resistant ring with cooling cavity according to claim 1, further comprising a wear-resistant ring setting portion on which the wear-resistant ring is set to restrict radial displacement of the wear-resistant ring. Set the wear-resistant ring on the set jig, and set the outer peripheral surface of the metal tube in contact with the inner peripheral surface of the wear-resistant ring, and set the two punches in the direction opposite to the one direction side in the piston axial direction. Are moved relative to each other in the direction opposite to the piston axial direction.

  The invention according to claim 4 is the method for producing a wear-resistant ring with a cooling cavity according to any one of claims 1 to 3, wherein the wear-resistant ring with a cooling cavity is cast into the piston body. The shape of the peripheral surface of the punch is formed so as to secure a distance at which a predetermined strength can be obtained between the wall surface of the combustion chamber formed on the upper surface of the piston body and the cooling cavity. .

  The invention according to claim 5 is the method for producing a wear-resistant ring with a cooling cavity according to any one of claims 1 to 4, wherein the wear-resistant ring is nijirest cast iron, iron-based sintered material, or austenitic system. It is composed of stainless steel.

  The invention according to claim 6 is the method for producing a wear-resistant ring with a cooling cavity according to any one of claims 1 to 5, wherein the metal tube is made of stainless steel, an aluminum alloy, or a copper alloy. It is characterized by.

  According to the present invention, since the metal tube is pressure-bonded to the wear-resistant ring by the relative movement of the punch with respect to the wear-resistant ring, a low-equipment is not required without a salt core elution process or a sintering process for sintering fitting. The metal tube and the wear-resistant ring can be easily integrated with a low cost and a small manufacturing process. Further, since the metal tube and the wear-resistant ring are integrated, the cooling capacity of the cooling cavity constituted by the metal tube is increased.

  Moreover, if a set jig provided with a wear-resistant ring set part and a metal tube set part is used, the metal pipe will be deformed according to the shape of the punch and the jig, and the degree of freedom of shape on the back of the wear-resistant ring A high cooling cavity can be formed integrally. Further, using a setting jig provided with a wear-resistant ring setting portion, setting the wear-resistant ring on the setting jig and setting the outer peripheral surface of the metal tube in contact with the inner peripheral surface of the wear-resistant ring, If the punch is moved relative to the piston shaft direction from the one direction side and the opposite direction side in the piston shaft direction, respectively, the metal tube is deformed according to the shape of the two punches. A cooling cavity having a high degree of freedom in shape can be integrally formed on the back surface of the wear-resistant ring.

  FIG. 1 is a cross-sectional view showing a piston 1 for an internal combustion engine (hereinafter simply referred to as a piston) provided with a wear-resistant ring with a cooling cavity according to the present invention.

  The piston head portion 2 of the piston 1 is provided with a wear resistant ring 4 made of Nijirest cast iron having a top ring groove 3 into which a piston ring (not shown) is incorporated. A cooling cavity 5 for recirculating engine oil for cooling the piston is integrally provided on the circumferential side. A second ring groove 6 and an oil ring groove 7 are formed below the top ring groove 3 on the outer periphery of the piston head portion 2.

  The cooling cavity 5 provided integrally on the inner peripheral side of the wear-resistant ring 3 includes a vertical surface 81 along the inner peripheral surface of the wear-resistant ring 3, a horizontal plane 82 extending from the lower end of the vertical surface 81 to the inner peripheral side, and the vertical It is surrounded by a stainless steel metal tube 8 having an inclined surface 83 inclined downward with respect to the central direction of the piston head portion 2 connecting the surface 81 and the horizontal surface 82. The horizontal surface 82 of the metal tube 8 is located below the lower end surface 31 of the wear-resistant ring 3.

  Next, a manufacturing method of the above-described wear-resistant ring 3 with a cooling cavity will be described with reference to FIG.

  First, as shown to Fig.2 (a), the wear ring 3 is set to the setting jig | tool 9, and the metal tube 8 of an elliptical cross section is set after that. The set jig 9 is in contact with the lower end surface 31 and the outer peripheral surface 32 of the set wear-resistant ring 3 so that the wear-resistant ring 3 is displaced in the radial direction (left-right direction in FIG. 2A) and in the piston axial direction (wear-resistant). A wear-resistant ring set portion that regulates displacement in one direction (downward in FIG. 2 (a)) in the direction perpendicular to both the circumferential direction and the radial direction of the ring 3 in the vertical direction in FIG. 2 (a). 91 and the wear-resistant ring setting portion 91 are formed one step lower on the inner peripheral side and abut the lower end of the set metal tube 8 to restrict the displacement of the metal tube 8 in one of the piston axial directions. And a metal tube setting unit 92. The metal tube 8 having an elliptical cross section can be manufactured by butt welding.

  Subsequently, the taper-shaped punch 10 having a circular cross section and tapering in the punch direction is moved from the other direction (upward in FIG. 2A) in the piston axial direction to one direction in the piston axial direction. Ten peripheral surfaces 101 are brought into contact with the inner peripheral side of the metal tube 8. Further, as shown in FIG. 2B, a load is applied to the punch 9 and moved in one direction of the piston axial direction, and the wear-resistant ring 3 and the metal tube 8 are bonded by pressure bonding. At this time, the metal pipe 8 is deformed so as to follow the inner peripheral surface 33 of the wear-resistant ring 3 and the step wall of the wear-resistant ring set portion 91 to form the vertical surface 81, so The horizontal surface 82 is formed by deformation. Further, the inclined surface 83 is formed by being deformed along the tapered punch 9.

  The anti-wear ring 3 with cooling cavity manufactured in this way is held in a predetermined mold (not shown), and molten metal of aluminum alloy is poured into the mold to perform gravity casting or low pressure casting. Is incorporated into the piston 1. After the casting process, a predetermined cutting process is performed to supply the top ring groove 3, the second ring groove 6 and the oil ring groove 7, a supply hole (not shown) for supplying engine oil into the cooling cavity 5, and a discharge hole for discharging. (Not shown) is formed.

  Thus, in this embodiment, since the metal tube 8 is pressure-bonded to the wear-resistant ring 3 by the movement of the punch 10 with respect to the wear-resistant ring 3, a salt core elution process and a sintering process for sintering fitting are performed. The metal pipe and the wear-resistant ring can be easily integrated with a low equipment cost and a small manufacturing process. Moreover, since the metal tube 8 and the wear-resistant ring 3 are integrated, the cooling capacity of the cooling cavity formed by the metal tube 8 is increased. Further, the metal tube 8 is deformed along the taper shape of the punch 10 to form the cooling cavity 5, so that the distance between the combustion chamber wall surface and the cooling cavity 5 is not less than a certain value without reducing the volume of the cooling cavity 5. Since they can be separated, the cooling capacity is increased.

  In the present embodiment, the metal tube 8 and the wear-resistant ring 3 are bonded by pressure bonding using the setting jig 9 provided with the metal tube setting portion 92 and one punch 10, but the present invention is applied to this. It is not limited. For example, as shown in FIGS. 3 (a) and 3 (b), using a set jig 9 provided with a wear-resistant ring setting portion 91 that restricts displacement in the radial direction of the wear-resistant ring 3 and two punches 10, a metal The tube 8 and the wear resistant ring 3 may be pressure bonded. Specifically, the wear-resistant ring 3 is set on the setting jig 9, and the outer peripheral surface of the metal tube is brought into contact with the inner peripheral surface of the wear-resistant ring 3 (FIG. 3A). Is moved in one direction and one direction from the one direction side and the opposite direction side in the piston axis direction, respectively, to deform the metal tube 8 and press-fit it against the wear-resistant ring 3 (FIG. 3B). The anti-wear ring 3 with the cooling cavity thus manufactured is also incorporated into the piston 1 through the predetermined casting process and cutting process as described above, and the top ring groove 3, the second ring groove 6, and the oil ring groove. 7. A supply hole (not shown) for supplying engine oil and a discharge hole (not shown) for discharging are formed in the cooling cavity 5. (FIG. 4).

  In the embodiment described above, the vertical cross-sectional shape of the punch 10 and the vertical cross-sectional shape of the inner peripheral surface of the wear-resistant ring 3 are linear, and the metal tube 8 is deformed during punching along these shapes. Is not limited to this. For example, as shown in FIGS. 5 (a) and 5 (b), by providing a non-tapered portion 102 at the tip of the punch 10 and further providing a ridge having a triangular cross section on the inner peripheral surface of the wear-resistant ring 3, the metal tube 8 The deformed shape can be a heptagon. The anti-wear ring 3 with the cooling cavity thus manufactured is also incorporated into the piston 1 through the predetermined casting process and cutting process as described above, and the top ring groove 3, the second ring groove 6, and the oil ring groove. 7. A supply hole (not shown) for supplying engine oil and a discharge hole (not shown) for discharging are formed in the cooling cavity 5. (FIG. 6).

  In the present embodiment, the metal tube 8 has an elliptical cross-sectional shape before punching, but the present invention is not limited to this, and is circular or oval. Also good.

  In this embodiment, the wear-resistant ring 3 is made of nigirest cast iron, but may be made of iron-based sintered material or austenitic stainless steel, and the metal tube is made of an aluminum alloy or copper instead of stainless steel. You may comprise with an alloy.

  In addition, this invention is not limited to the thing of the said embodiment, A various change is possible as needed.

Sectional drawing which shows the piston which arrange | positioned the wear-resistant ring with a cooling cavity which concerns on one Embodiment of this invention. Diagram showing the manufacturing process of wear-resistant ring with cooling cavity The figure which shows the manufacturing process of the wear-resistant ring with a cooling cavity which concerns on other embodiment of this invention. Sectional view showing a piston with a wear-resistant ring with cooling cavity The figure which shows the manufacturing process of the wear-resistant ring with a cooling cavity which concerns on other embodiment of this invention. Sectional view showing a piston with a wear-resistant ring with cooling cavity Sectional drawing which shows the piston which arrange | positioned the wear-resistant ring with a cooling cavity in a prior art example

Explanation of symbols

1 Wear-resistant ring 5 Cooling cavity 8 Metal tube 9 Set jig 10 Punch

Claims (6)

In the method of manufacturing a wear-resistant ring in which a piston ring is cast into a piston body and a piston ring is incorporated, and an annular cooling cavity for refluxing cooling oil is attached to the inner peripheral side,
An annular metal tube having an outer diameter substantially the same as the inner diameter of the wear ring is set on the inner circumference side of the ring wear ring,
The circumferential surface of the punch having a circular cross section and a tapered shape is brought into contact with the inner peripheral side of the metal tube,
A load is applied to the punch, and the wear-resistant ring and the metal tube are pressure-bonded to the wear-resistant ring by relatively moving in the piston axial direction perpendicular to both the circumferential direction and the radial direction of the wear-resistant ring,
A manufacturing method of a wear-resistant ring with a cooling cavity, wherein the cooling cavity is constituted by the pressure-bonded metal pipe. A wear resistant ring is set to restrict the radial displacement of the wear resistant ring and the displacement in one direction of the piston axial direction, and a metal tube is set on the inner peripheral side of the wear resistant ring set portion. A wear-resistant ring and a metal tube are set on a setting jig provided with a metal tube setting portion that restricts displacement in one direction of the piston axial direction, and the punch is moved from the other direction side of the piston axial direction. 2. The method for producing a wear-resistant ring with a cooling cavity according to claim 1, wherein the ring is relatively moved in one direction. The wear-resistant ring is set on a setting jig provided with a wear-resistant ring setting portion for restricting radial displacement of the wear-resistant ring, and the outer peripheral surface of the metal tube is applied to the inner peripheral surface of the wear-resistant ring. The two punches are moved relative to each other in one direction and one direction in the piston axis direction from the one direction side and the opposite direction side in the piston axis direction, respectively. A method for producing a wear-resistant ring with cooling cavities as described in 1. When a wear-resistant ring with a cooling cavity is cast in the piston body, the distance between the cooling chamber and the wall of the combustion chamber formed on the upper surface of the piston body and a cooling cavity can be secured. The shape of the peripheral surface of a punch is formed, The manufacturing method of the wear-resistant ring with a rejection cavity of any one of Claims 1-3 characterized by the above-mentioned. The method of manufacturing a wear-resistant ring with a cooling cavity according to any one of claims 1 to 4, wherein the wear-resistant ring is made of nigirest cast iron, iron-based sintered material, or austenitic stainless steel. The said metal pipe is comprised with stainless steel, aluminum alloy, or copper alloy, The manufacturing method of the wear-resistant ring with a cooling cavity of any one of Claims 1-5 characterized by the above-mentioned.

Images