WO2017122474A1 - Procédé de production d'un piston, et piston - Google Patents

Procédé de production d'un piston, et piston Download PDF

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Publication number
WO2017122474A1
WO2017122474A1 PCT/JP2016/086692 JP2016086692W WO2017122474A1 WO 2017122474 A1 WO2017122474 A1 WO 2017122474A1 JP 2016086692 W JP2016086692 W JP 2016086692W WO 2017122474 A1 WO2017122474 A1 WO 2017122474A1
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WO
WIPO (PCT)
Prior art keywords
low heat
heat conduction
piston
pressing
manufacturing
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Application number
PCT/JP2016/086692
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English (en)
Japanese (ja)
Inventor
高橋　智一
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日立オートモティブシステムズ株式会社
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Publication of WO2017122474A1 publication Critical patent/WO2017122474A1/fr

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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02F—CYLINDERS, PISTONS OR CASINGS, FOR COMBUSTION ENGINES; ARRANGEMENTS OF SEALINGS IN COMBUSTION ENGINES
    • F02F3/00—Pistons 
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02F—CYLINDERS, PISTONS OR CASINGS, FOR COMBUSTION ENGINES; ARRANGEMENTS OF SEALINGS IN COMBUSTION ENGINES
    • F02F3/00—Pistons 
    • F02F3/10—Pistons  having surface coverings
    • F02F3/12—Pistons  having surface coverings on piston heads
    • F02F3/14—Pistons  having surface coverings on piston heads within combustion chambers
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02F—CYLINDERS, PISTONS OR CASINGS, FOR COMBUSTION ENGINES; ARRANGEMENTS OF SEALINGS IN COMBUSTION ENGINES
    • F02F3/00—Pistons 
    • F02F3/26—Pistons  having combustion chamber in piston head
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16J—PISTONS; CYLINDERS; SEALINGS
    • F16J1/00—Pistons; Trunk pistons; Plungers
    • F16J1/01—Pistons; Trunk pistons; Plungers characterised by the use of particular materials

Definitions

  • the present invention relates to a piston manufacturing method and a piston.
  • Patent Document 1 discloses a structure in which a cavity is formed on the top surface of a piston made of an aluminum alloy, and a low thermal conductivity member having a low thermal conductivity is attached to the bottom surface of the cavity.
  • an object of the present invention is to provide a piston manufacturing method and a piston capable of providing a low heat conductive member at a position corresponding to the fuel injection region of the piston. .
  • an annular low heat conduction part formed of a low heat conduction part forming material which is a material having a lower thermal conductivity than an aluminum alloy, is provided on the piston body part.
  • a step of forming the crown portion on the combustion chamber side of the internal combustion engine, and a lower heat conduction portion forming material inside the inner peripheral edge of the annular low heat conduction portion in a cross section orthogonal to the moving direction of the piston in the cylinder of the internal combustion engine In addition, a low thermal conduction part forming step of forming a low thermal conduction part so as to have a non-low thermal conduction part made of a material having high thermal conductivity is provided.
  • the piston of the internal combustion engine is formed of a low heat conduction part forming material that is provided on the combustion chamber side of the internal combustion engine at the crown of the piston and has a lower thermal conductivity than the aluminum alloy.
  • the low heat conduction portion can be provided at a position corresponding to the fuel injection amount region.
  • FIG. 1 is a perspective view of a piston of an internal combustion engine of Embodiment 1.
  • FIG. 3 is a flowchart showing manufacturing steps of the piston of Example 1.
  • FIG. 3 is a view showing a piston after completion of a primary machining process of Example 1.
  • FIG. 3 is a view showing the piston after completion of the mixed powder filling step of Example 1.
  • FIG. 3 is a view showing the piston after execution of the mixed powder pressing step of Example 1.
  • FIG. 3 is a view showing the piston after the mixed powder pressing step of Example 1 is completed.
  • FIG. 3 is a view showing a piston after completion of the secondary machining process of the first embodiment.
  • 6 is a perspective view of a piston according to Embodiment 2.
  • FIG. 5 is a flowchart showing a manufacturing process of a piston of Example 2.
  • FIG. 5 is a flowchart showing a manufacturing process of a piston of Example 2.
  • FIG. 6 is a view showing a piston after completion of a primary machining process of Example 2.
  • 5 is a perspective view of a preform of Example 2.
  • FIG. FIG. 5 is a view showing a piston after completion of a preform arranging step in Example 2.
  • FIG. 6 is a view showing a piston when a preform pressing process of Example 2 is performed.
  • FIG. 6 is a view showing a piston at the end of a pressing step in Example 2.
  • FIG. 6 is a view showing a piston after completion of a pressing step in Example 2.
  • FIG. 6 is a view showing the shape of a piston after the completion of the secondary machining process of Example 2.
  • 6 is a perspective view of a piston of Example 3.
  • FIG. FIG. 6 is a perspective view of a piston of an internal combustion engine according to a fourth embodiment.
  • FIG. 1 is a perspective view of a piston 1 of an internal combustion engine.
  • the piston 1 is formed using an aluminum alloy as a base material.
  • the piston 1 according to the first embodiment is used in a cylinder injection type internal combustion engine.
  • the piston 1 is formed in a substantially cylindrical shape.
  • the surface (top surface) on the combustion chamber side in the axial direction of piston 1 (the direction in which piston 1 reciprocates within the cylinder) constitutes crown 2.
  • a low heat conduction portion 3 is formed in the crown portion 2.
  • the low heat conducting portion 3 is formed in an annular shape in a cross section orthogonal to the axial direction of the piston 1.
  • the low heat conducting portion 3 is formed in a single ring over the entire circumference of the crown portion 2 inside the outermost circumference of the crown portion 2.
  • the low heat conduction part 3 is formed of a material having a lower thermal conductivity than the aluminum alloy.
  • the material of the low heat conduction part 3 will be described in detail later.
  • the material on the inner peripheral side of the low heat conducting portion 3 is an aluminum alloy.
  • the inner peripheral side of the low heat conducting portion 3 constitutes a non-low heat conducting portion 2b.
  • the entire outer periphery of the outer peripheral edge of the low heat conducting portion 3 is surrounded by an aluminum alloy.
  • the entire outer periphery of the outer peripheral edge of the low heat conducting portion 3 is surrounded by an aluminum alloy.
  • a ring groove 4 is formed over the entire circumference.
  • the ring groove 4 is formed at three positions apart in the axial direction, and constitutes a top ring groove 4a, a second ring groove 4b, and an oil ring groove 4c in order from the crown portion 2 side.
  • a cylinder ring is engaged with each of the top ring groove 4a and the second ring groove 4b.
  • An oil ring is engaged with the oil ring groove 4c.
  • a skirt portion 5 is formed below the oil ring groove 4c.
  • the skirt portion 5 is formed at two locations separated in the circumferential direction.
  • the skirt portions 5 are formed at positions facing each other.
  • the outer peripheral surface of the skirt portion 5 is formed in a substantially cylindrical shape.
  • the crown part 2, the skirt part 5, and the land part 8 constitute the main body part 9.
  • the boss part 6 is formed at a position substantially orthogonal to the opposing skirt part 5 with the skirt part 5 sandwiched therebetween. .
  • the boss portion 6 is formed with a pin hole 6a into which a piston pin for assembling the connecting rod to the piston 1 so as to be rotatable is inserted.
  • FIG. 2 is a flowchart showing the manufacturing process of the piston 1.
  • FIG. 3 shows the piston 1 after the primary machining process.
  • FIG. 4 is a view showing the piston 1 after the mixed powder filling step.
  • FIG. 5 is a view showing the piston 1 during the mixed powder pressing step.
  • FIG. 6 is a view showing the piston 1 after the mixed powder pressing step.
  • FIG. 7 shows the piston 1 after the secondary machining process.
  • Step S1 is a piston 1 casting process. In the piston casting process, the rough material of the piston 1 is cast with an aluminum alloy. In this step, the main body 9 is formed.
  • Step S2 is a primary machining process (FIG. 3).
  • the annular groove 2a is formed by processing a concave groove over the entire circumference in the crown portion 2.
  • the annular groove 2a is filled with the material of the low heat conducting portion 3 in a later step.
  • the annular groove 2a may be formed by casting in the casting process.
  • Step S3 is a mixed powder filling process (FIG. 4).
  • the mixed powder 3a which is the material of the low heat conduction part 3, is filled into the annular groove 2a.
  • the mixed powder 3a is alloyed with a powder of a material having a lower thermal conductivity (low thermal conductivity material) than an aluminum alloy that is a material of the main body 9 of the piston 1 and an aluminum alloy that is a material of the main body 9 by plastic flow. It consists of a powder of a material (joining material) that can be an intermetallic compound.
  • Step S4 is a mixed powder pressing step (FIGS. 5 and 6).
  • the mixed powder pressing step the cylindrical tool 7 is rotated in the circumferential direction while pressing the mixed powder 3a into the annular groove 2a by the cylindrical tool 7. Thereby, the joining material is softened and stirred. Therefore, the low thermal conductive material can be held in the bonding material.
  • the bonding material is alloyed with the aluminum alloy that is the material of the main body 9, or forms an intermetallic compound.
  • a method similar to the friction stir welding is used.
  • the low heat conducting portion 3 is integrated with the aluminum alloy portion that is the material of the main body portion 9.
  • a stirring trajectory when the joining member is stirred by the cylindrical tool 7 remains on the surface of the low heat conducting portion 3.
  • the volume of the low heat conductive portion 3 is reduced from the state of the mixed powder 3a and is not exposed on the surface of the crown portion 2.
  • the inner diameter of the cylindrical tool 7 is slightly smaller than the inner diameter of the annular groove 2a (the diameter of the side surface on the radially inner side of the groove).
  • the outer diameter of the cylindrical tool 7 is slightly larger than the outer diameter of the annular groove 2a (the diameter of the side surface on the radially outer side of the groove).
  • Step S5 is a heat treatment process.
  • the piston 1 after the mixed powder pressing step is heat treated.
  • Step S6 is a secondary machining process (FIG. 7).
  • the secondary machining process the piston 1 is finished by a machine tool. At this time, the crown portion 2 is cut, and the low heat conduction portion 3 is exposed on the surface of the crown portion 2. Further, the ring groove 4 is formed in the secondary machining process.
  • the piston 1 Since the piston 1 has a large volume, the heat capacity is large and the temperature of the piston 1 does not rise rapidly. Further, since the piston 1 is made of an aluminum alloy, heat conductivity is high, and heat received from the fuel gas in the cylinder at the crown portion 2 is transmitted from the piston ring or the skirt portion 5 to the cylinder. Therefore, the temperature rise of the piston 1 is gradual.
  • the piston 1 of the first embodiment is used for a cylinder injection internal combustion engine. The fuel injected into the cylinder evaporates in the cylinder, but part of it collides with the crown 2 of the piston 1. When the temperature of the piston 1 is sufficiently high, when the fuel collides with the crown 2, the fuel receives heat from the piston 1 and evaporates.
  • the temperature of the piston 1 is moderately increased, the temperature of the piston 1 is low when the internal combustion engine is started, and there is a possibility that fuel that cannot be evaporated on the crown portion 2 remains as a liquid film. The fuel remaining on the crown 2 causes deposits and contamination of unburned hydrocarbons into the exhaust.
  • Example 1 the low thermal conductivity portion 3 having a lower thermal conductivity than the aluminum alloy that forms the piston 1 is formed in the crown portion 2.
  • the heat received from the fuel gas in the low heat conducting section 3 is not easily transmitted to other parts, and the temperature rise of the low heat conducting section 3 can be accelerated. Therefore, the fuel that has collided with the low heat conducting section 3 is likely to evaporate.
  • the low heat conduction portion 3 is formed in an annular shape at the radially outer portion of the crown portion 2. Formed.
  • the low heat conduction portion 3 can be provided at a position corresponding to the fuel injection amount region.
  • the crown 2 of the piston 1 is filled with the mixed powder 3a in the annular groove 2a, and the mixed powder 3a is pressed by the cylindrical tool 7 so as to pack the mixed powder 3a into the annular groove 2a in the circumferential direction. It was made to rotate to.
  • the annular low heat conduction portion 3 can be formed at a time.
  • Example 1 the aluminum alloy of the main body portion 9 is provided on the inner peripheral side of the annular low heat conducting portion 3. Thereby, it is not necessary to use an inner peripheral side of the low heat conducting portion 3 other than the aluminum alloy that is the material of the main body portion 9. Further, since the meat of the main body 9 is present inside the inner peripheral edge of the low heat conduction part 3, the mixed powder 3a is difficult to escape inside the low heat conduction part 3 in the mixed powder pressing step, and it is easy to apply pressure to the mixed powder 3a. Become. In Example 1, the entire outer periphery of the outer peripheral edge of the annular groove 2a is surrounded by the aluminum alloy of the main body 9.
  • the meat of the main body 9 is present outside the outer peripheral edge of the low heat conduction part 3, so that the mixed powder 3a is difficult to escape outside the low heat conduction part 3 in the mixed powder pressing step, and pressure is applied to the mixed powder 3a. It becomes easy.
  • the forming material of the low heat conducting portion 3 was the powder mixed powder 3a. Accordingly, the mixed powder pressing step can be performed in a state where the bonding material and the low heat conductive material are uniformly mixed in the annular groove 2a, and the low heat conductive portion 3 can be made of a uniform material.
  • a method for manufacturing a piston 1 of an internal combustion engine includes a casting step (main body portion forming step) in which a main body portion 9 having a crown portion 2 and a skirt portion 5 provided on the crown portion 2 is formed of an aluminum alloy.
  • an annular low heat conduction part 3 formed of a low heat conduction material which is a material having a lower thermal conductivity than aluminum alloy, on the combustion chamber side of the internal combustion engine in the crown part 2
  • the low heat conduction part forming step is a mixed powder filling step (filling step) of filling the mixed powder 3a (low heat conduction part forming material) into the annular groove 2a (concave part) provided on the combustion chamber side of the crown part 2. And a mixed powder pressing step (pressing step) in which the mixed powder 3a (low heat conduction portion forming material) in the annular groove 2a (recessed portion) is pressed by the rotating cylindrical tool 7 (tool). By performing the mixed powder pressing step using the cylindrical tool 7, the annular low heat conduction portion 3 can be formed at a time.
  • the non-low heat conduction part 2b is made of an aluminum alloy of the main body part 9.
  • the low heat conduction part forming step includes a step of filling the annular groove 2a (annular recess) provided on the combustion chamber side of the crown 2 with the mixed powder 3a (low heat conduction part forming material), and the annular groove 2a ( A mixed powder pressing step (pressing step) for pressing the mixed powder 3a (low heat conduction portion forming material) in the annular recess) with a rotating cylindrical tool 7 (tool), and the annular groove 2a (annular recess)
  • a mixed powder pressing step pressing step for pressing the mixed powder 3a (low heat conduction portion forming material) in the annular recess) with a rotating cylindrical tool 7 (tool), and the annular groove 2a (annular recess)
  • the entire outer periphery of the outer peripheral edge of the annular groove 2a (annular recess) is surrounded by the aluminum alloy of the main body 9.
  • the mixed powder 3a (low heat conduction part forming material) was used as a powder mixed material. Accordingly, the mixed powder pressing step can be performed in a state where the bonding material and the low heat conductive material are uniformly mixed in the annular groove 2a, and the low heat conductive portion 3 can be made of a uniform material.
  • a piston 1 of an internal combustion engine which is made of an aluminum alloy and has a crown portion 2 and a main body portion 9 provided with a skirt portion 5 provided on the crown portion 2, and combustion of the crown portion 2 of the internal combustion engine
  • a non-low heat conductive portion 2b provided on the inner side and formed of a material having higher thermal conductivity than the mixed powder 3a (low heat conductive portion forming material).
  • Example 2 In the piston 1 of Example 1, the entire outer periphery of the outer peripheral edge of the low heat conducting portion 3 was surrounded by an aluminum alloy. In Example 2, it was formed so that the entire outer periphery of the outer peripheral edge of the low thermal conductive portion 3 was exposed.
  • the piston 1 of the second embodiment will be described, but the same components as those of the first embodiment are denoted by the same reference numerals and the description thereof will be omitted.
  • FIG. 8 is a perspective view of the piston 1 of the second embodiment.
  • a low heat conduction portion 3 is formed in the crown portion 2 of the piston 1.
  • the low heat conducting portion 3 is formed in an annular shape in a cross section orthogonal to the axial direction of the piston 1.
  • the low heat conducting portion 3 is formed in a single ring over the entire circumference of the crown portion 2 on the outermost circumference of the crown portion 2.
  • the low heat conduction part 3 is formed of a material having a lower thermal conductivity than the aluminum alloy.
  • the material on the inner peripheral side of the low heat conducting portion 3 is an aluminum alloy.
  • the inner peripheral side of the low heat conducting portion 3 constitutes a non-low heat conducting portion 2b.
  • the low heat conducting portion 3 is provided so that the outer peripheral surface is exposed.
  • FIG. 9 is a flowchart showing the manufacturing process of the piston 1.
  • FIG. 10 is a view showing the piston 1 after completion of the primary machining process.
  • FIG. 11 is a perspective view of the preform 3b.
  • FIG. 12 is a view showing the piston 1 after completion of the preform arranging step.
  • FIG. 13 is a view showing the piston 1 when the preform pressing process is performed.
  • FIG. 14 shows the piston 1 at the end of the pressing step.
  • FIG. 15 is a view showing the piston 1 after completion of the pressing step.
  • FIG. 16 is a view showing the shape of the piston 1 after completion of the secondary machining process.
  • Step S11 is a casting process of the piston 1. In the piston casting process, the rough material of the piston 1 is cast with an aluminum alloy.
  • Step S12 is a primary machining process.
  • the outer diameter of the rough land of the piston 1 is cut by the machine tool, the outer diameter of the skirt 5 is cut, the boss 6 is processed, the pin hole 6a is processed, and the annular groove 2a of the crown 2 is formed.
  • Perform processing The annular groove 2a is formed by processing a concave groove over the entire circumference in the crown portion 2.
  • the annular groove 2a is provided with a low heat conduction portion 3 in a later step.
  • the annular groove 2a is formed so that the outer peripheral side is exposed after the low heat conducting portion 3 is provided.
  • the annular groove 2a may be formed by casting in the casting process.
  • the fixing jig 10 is formed in a cylindrical shape.
  • the inner diameter of the fixing jig 10 is substantially the same as the outer diameter of the land portion 8 of the piston 1 and is formed so that the piston 1 can be accommodated on the inner periphery.
  • the height of the fixing jig 10 is substantially the same as the height of the piston 1 in the axial direction.
  • Step S13 is a green compact forming process.
  • the mixed powder 3a is filled in the annular groove 2a.
  • the annular preform 3b is formed from the low heat conductive material and the bonding material.
  • the preform 3b is formed as a green compact by mixing and pressing a powdery low thermal conductive material and a bonding material.
  • Step S14 is a green compact heat treatment process. After forming the preform 3b as a green compact, the preform 3b is heated. As a result, the particulate low thermal conductive material and the oxide film covering the surface of the bonding material are broken, and the particles are easily bonded to each other. Therefore, the preform 3b is not easily collapsed.
  • Step S15 is a preform placement process.
  • Step S16 is a preform pressing process.
  • the cylindrical tool 7 is rotated in the circumferential direction while pressing the preform 3b so as to be packed in the annular groove 2a.
  • the joining material is softened and stirred. Therefore, the low thermal conductive material can be held in the bonding material.
  • the bonding material is alloyed with the aluminum alloy that is the material of the main body 9, or forms an intermetallic compound.
  • the low heat conducting portion 3 is integrated with the aluminum alloy portion that is the material of the main body portion 9.
  • a stirring trajectory when the joining member is stirred by the cylindrical tool 7 remains on the surface of the low heat conducting portion 3.
  • the volume of the low heat conductive portion 3 is reduced from the state of the mixed powder 3a and is not exposed on the surface of the crown portion 2.
  • the inner diameter of the cylindrical tool 7 is formed to be approximately the same as the inner diameter of the annular groove 2a (the diameter of the side surface on the radially inner side of the groove).
  • the outer diameter of the cylindrical tool 7 is formed to be approximately the same as the outer diameter of the land portion 8 of the piston 1.
  • the preform 3b of Example 2 is a green compact, and therefore there is little risk of leakage from the annular groove 2a. Therefore, unlike the first embodiment, it is not necessary to make the width of the cylindrical tool 7 larger than the width of the annular groove 2a so as to overlap and contact the main body 9 other than the annular groove 2a.
  • Step S17 is a heat treatment process.
  • the piston 1 that has undergone the preform pressing step is subjected to heat treatment.
  • the strain associated with the plastic flow during the preform pressing step is removed, and the strength is made uniform.
  • Step S18 is a secondary machining process.
  • the piston 1 is finished by a machine tool. At this time, the crown portion 2 is cut, and the low heat conduction portion 3 is exposed on the surface of the crown portion 2. Further, the ring groove 4 is formed in the secondary machining process.
  • the top ring groove 4a is formed on the outer peripheral surface of the low heat conducting portion 3.
  • Example 2 The effects of Example 2 are listed below.
  • Primary machining peripheral part removing step
  • the low heat conduction part 3 can be provided on the outermost peripheral side of the crown surface 2 of the piston 1. Therefore, in the internal combustion engine in which the fuel injection region exists on the outermost peripheral side of the crown portion 2, the low heat conduction portion 3 can be provided at a position corresponding to the fuel injection amount region.
  • the preform 3b (low heat conduction part forming material) is a material having a hardness higher than that of the aluminum alloy, and the low heat conduction part forming step is performed so that the low heat conduction part 3 is exposed to the outer peripheral side of the piston 1.
  • a secondary machining step (ring groove forming step) for forming the top ring groove 4a into which the piston ring is inserted on the outer peripheral side of the low heat conducting portion 3 is further provided. Thereby, the strength of the top ring groove 4a can be improved.
  • the low heat conduction part forming step is a preform setting step in which the annular groove 2a (concave part) provided in the outermost peripheral part on the combustion chamber side of the crown part 2 is filled with the preform 3b (low heat conduction part forming material).
  • the preform pressing step (pressing step) was performed in a state where the outer peripheral side of the main body 9 was surrounded by the fixing jig 10 (mold).
  • the low thermal conduction part forming process includes a green compact forming process (compacting process) for forming a green compact obtained by pressing a powder mixed material that is a preform 3b (low thermal conductive part forming material), a crown A preform arranging step (arranging step) in which the green compact is arranged in an annular groove 2a (concave portion) provided on the combustion chamber side of the portion 2. This makes it difficult for the preform 3b to escape from the annular groove 2a in the preform pressing step.
  • the low thermal conduction part forming step further includes a pre-farm heat treatment step (heat treatment step) performed after the green compact formation step (compact step) and before the preform placement step (placement step). did. Thereby, the preform 3b can be made difficult to collapse, and the preform 3b can be made difficult to escape in the preform pressing step.
  • the low heat conduction portion forming step is a preform arrangement step (filling step) in which the annular groove 2a (concave portion) provided on the combustion chamber side of the crown portion 2 is filled with the preform 3b (low heat conduction portion forming material).
  • the preform 3b (low heat conduction portion forming material) is a material having a hardness higher than that of the aluminum alloy, and the crown portion 2 is provided on the outer peripheral side of the crown portion 2 and is a top ring groove into which a piston ring is inserted. It has 4a (ring groove), and the low heat conduction part 3 is provided in a range including the top ring groove 4a (ring groove). Thereby, the strength of the top ring groove 4a can be improved.
  • Example 3 In Example 1, it was formed in a single ring over the entire circumference of the low thermal conductivity portion 3 and the crown portion 2. In Example 3, the low heat conductive portion 3 is formed in a plurality of annular shapes.
  • the piston 1 of the third embodiment will be described, but the same components as those of the first embodiment are denoted by the same reference numerals and the description thereof will be omitted.
  • FIG. 17 is a perspective view of the piston 1 of the third embodiment.
  • a low heat conduction portion 3 is formed in the crown portion 2 of the piston 1.
  • the low heat conducting portion 3 is formed in an annular shape in a cross section orthogonal to the axial direction of the piston 1.
  • a plurality of low heat conduction portions 3 are formed and arranged in the circumferential direction of the crown portion 2.
  • the low heat conduction part 3 is formed of a material having a lower thermal conductivity than the aluminum alloy.
  • the material on the inner peripheral side of the low heat conducting portion 3 is an aluminum alloy.
  • the inner peripheral side of the low heat conducting portion 3 constitutes a non-low heat conducting portion 2b.
  • the annular groove 2a is formed in the same manner as in Example 1, and the mixed powder 3a is pressed by the cylindrical tool 7 after filling the annular groove 2a with the mixed powder 3a. May be formed.
  • the preform 3b may be disposed in the annular groove 2a.
  • the pressing process may be performed eight times with one cylindrical tool 7. Further, the pressing process may be performed once by the eight cylindrical tools 7. In any method, there are a plurality of rotation centers of the cylindrical tool 7 in a cross section orthogonal to the moving direction of the piston 1 in the cylinder.
  • the cylindrical tool 7 since the size of one low heat conducting portion 3 is small, the cylindrical tool 7 can also be made small. Therefore, the pressing force of the mixed powder 3a or the preform 3b by the cylindrical tool 7 can be suppressed, and the deformation of the piston 1 in the pressing process can be suppressed.
  • the low heat conduction part forming step is a mixed powder filling (filling step) in which the mixed powder 3a (low heat conduction part forming material) is filled in the annular groove 2a (concave part) provided on the combustion chamber side of the crown part 2.
  • a mixed powder pressing step pressing step for pressing the mixed powder 3a (low heat conduction portion forming material) in the annular groove 2a (recessed portion) with a rotating cylindrical tool 7 (tool), and a mixed powder pressing step ( The pressing step) is performed so that there are a plurality of rotation centers of the cylindrical tool 7 (tool) in a cross section orthogonal to the moving direction of the piston 1.
  • the low heat conduction part forming step is a mixed powder filling step (filling step) of filling the mixed powder 3a (low heat conduction part forming material) into the annular groove 2a (concave part) provided on the combustion chamber side of the crown part 2.
  • the low heat conduction section 3 has a plurality of parts to be stirred having a stirring locus in which the mixed powder 3a (low heat conduction forming member) is stirred around the stirring center in a cross section orthogonal to the moving direction of the piston 1. As a result, a plurality of low heat conduction parts 3 can be formed, and the low heat conduction part 3 having an appropriate shape can be formed at an appropriate position in accordance with the fuel injection region.
  • Example 4 In Example 1, it was formed in a single ring over the entire circumference of the low thermal conductivity portion 3 and the crown portion 2.
  • the second low heat conduction part 11 is further formed on the inner peripheral side of the annular low heat conduction part 3 formed in the same manner as in Example 1.
  • FIG. 18 is a perspective view of the piston 1 of the internal combustion engine. A low heat conduction portion 3 and a second low heat conduction portion 11 are formed in the crown portion 2 of the piston 1.
  • the low heat conducting portion 3 is formed in a single ring over the entire circumference of the crown portion 2 as in the first embodiment.
  • a circular second low heat conduction portion 11 is formed in the central portion of the crown portion 2.
  • a non-low heat conduction part 2b is provided between the low heat conduction part 3 and the second low heat conduction part 11.
  • the non-low heat conduction part 2b is a part of the main body part 9, and is formed of an aluminum alloy.
  • the annular groove 2a is formed in the same manner as in Example 1, and the mixed powder 3a is pressed by the cylindrical tool 7 after filling the annular groove 2a with the mixed powder 3a. May be formed.
  • a cylindrical recess is formed instead of the annular groove 2a, and after the mixed powder 3a is filled in this recess, it is matched with the shape of the cylindrical recess. What is necessary is just to form so that the mixed powder 3a may be pressed with the formed cylindrical tool. Further, a preform 3b may be disposed instead of the mixed powder 3a as in the second embodiment.
  • the low heat conduction part 3 and the second low heat conduction part 11 are not pressed at once using the cylindrical tool 7 or the columnar tool, but have a diameter smaller than the width of the annular groove 2a and the diameter of the cylindrical recess. You may make it press the mixed powder 3a and the preform 3b, moving a tool using a tool.
  • the step of pressing the mixed powder 3a (low heat conduction portion forming material) is performed while moving the tool. Thereby, it is not necessary to prepare a tool according to the shape of the low heat conduction part 3. In addition, a continuous low heat conducting portion 3 can be formed.
  • the present invention has been described based on the first to fourth embodiments.
  • the specific configuration of each invention is not limited to the first to fourth embodiments, and does not depart from the gist of the present invention.
  • Such design changes are included in the present invention.
  • the mixed powder 3a is filled in the annular groove 2a.
  • the preform 3b may be disposed in the annular groove 2a.
  • the preform 3b is disposed in the annular groove 2a.
  • the mixed powder 3a may be filled in the annular groove 2a.
  • the mixed powder 3a or the preform 3b was pressed by the cylindrical tool 7, but using a tool having a diameter smaller than the width of the annular groove 2a, the tool was moved.
  • the mixed powder 3a and the preform 3b may be pressed.
  • the non-low heat conduction part 2b on the inner peripheral side of the low heat conduction part 3 is a part of the main body part 9, and is formed of an aluminum alloy.
  • the non-low heat conduction part 2b may be formed of a material different from that of the main body part 9.
  • the shapes of the low thermal conductive material and the bonding material in Examples 1 to 4 are not limited to powder, but may be flakes or chips.
  • a hollow porous ceramic bead, a hollow glass bead, and a hollow metal sphere can be used in addition to a filler having a fine porous structure mainly composed of silica, silica gel, silica airgel, and the like.
  • high strength and high heat resistance ceramic fibers low heat conductivity and low specific heat heat resistant metal materials such as titanium, titanium alloys, SUS, low alloys Powders of steel, cast iron (gray cast iron, spheroidal graphite cast iron) and the like can be used similarly.
  • metal materials such as titanium, titanium alloys, SUS, low alloys Powders of steel, cast iron (gray cast iron, spheroidal graphite cast iron) and the like can be used similarly.
  • a method for manufacturing a piston of an internal combustion engine is as follows: A body part forming step of forming a body part having a crown part and a skirt part provided in the crown part from an aluminum alloy; A step of forming an annular low heat conduction part formed of a low heat conduction part forming material having a lower thermal conductivity than the aluminum alloy on the combustion chamber side of the internal combustion engine in the crown part, A non-low heat conduction part formed of a material having a higher thermal conductivity than the low heat conduction part forming material is provided inside the inner peripheral edge of the annular low heat conduction part in a cross section orthogonal to the moving direction of the piston in the cylinder. And a low thermal conduction part forming step for forming the low thermal conduction part.
  • the low thermal conduction portion forming step includes a filling step of filling the concave portion provided on the combustion chamber side in the crown portion with the low thermal conduction portion forming material, and a tool for rotating the low thermal conduction portion forming material in the concave portion.
  • a pressing step of pressing with, The pressing step is performed such that a plurality of rotation centers of the tool exist in a cross section orthogonal to the moving direction of the piston.
  • the step of pressing the low heat conduction portion forming material with the tool is performed a plurality of times. Thereby, a pressure can be efficiently applied to the low heat conduction part forming material with a tool, and the adhesiveness of the low heat conduction part can be improved.
  • the pressing step is performed while the tool is moved in the step of pressing the low heat conduction portion forming material. Thereby, it is not necessary to prepare a tool according to the shape of the low heat conduction part. Moreover, the continuous low heat conductive part can be formed.
  • the low heat conduction portion forming step includes a filling step of filling the concave portion provided on the combustion chamber side in the crown portion with the low heat conduction portion forming material, and an annular shape rotating the low heat conduction portion forming material in the concave portion. Pressing with a tool. By performing the pressing step using an annular tool, an annular low heat conduction portion can be formed at a time.
  • the non-low heat conduction part is the aluminum alloy of the main body part.
  • the aluminum alloy which is a raw material of a main-body part for the inner peripheral side of a low heat conductive part.
  • flour of a main-body part exists inside the inner periphery of a low heat conductive part, mixed powder cannot escape easily inside a low heat conductive part in a press process, and it becomes easy to apply a pressure to mixed powder.
  • the low heat conduction part forming step includes a step of filling the annular recess provided on the combustion chamber side in the crown with the low heat conduction part forming material, and rotating the low heat conduction part forming material in the annular recess. Pressing with a tool, and In the annular recess, the entire outer periphery of the outer peripheral edge of the annular recess is surrounded by the aluminum alloy of the main body.
  • flour of a main-body part exists outside the outer periphery of a low heat conductive part, mixed powder cannot escape easily to the outer side of a low heat conductive part in a mixed powder press process, and it becomes easy to apply a pressure to mixed powder.
  • the low heat conduction part forming material is a material having a higher hardness than the aluminum alloy
  • the low heat conduction part forming step is performed such that the low heat conduction part is exposed on the outer peripheral side of the piston, It further has a ring groove forming step of forming a ring groove into which a piston ring is inserted on the outer peripheral side of the low heat conducting portion. As a result, the strength of the ring groove can be improved.
  • the low heat conduction portion forming step includes a filling step of filling the concave portion provided in the outermost peripheral portion on the combustion chamber side of the crown portion with the low heat conduction portion forming material, and the low heat conduction portion forming material in the concave portion. Pressing with a rotating tool, and The pressing step is performed in a state where the outer peripheral side of the main body is surrounded by a mold. Thereby, even if it is a case where the thickness of a crown part does not exist in the outer peripheral side from a low heat conductive part, the escape of the low heat conductive part formation material can be suppressed by a type
  • the low heat conduction part forming material is a mixed powder material.
  • a press process can be performed in the state with which the low heat conductive part formation material was mixed uniformly in the recessed part of a crown part, and a low heat conductive part can be made into a uniform material.
  • the low thermal conduction portion forming step is provided on the combustion chamber side of the crown portion, and a compacting step of forming a green compact by pressing the mixed material of the powder that is the low thermal conduction portion forming material. An arrangement step of arranging the green compact in the recess.
  • the low heat conduction part forming step further includes a heat treatment step performed after the compacting step and before the arranging step. Thereby, the green compact can be made difficult to collapse, and the green compact can be made difficult to escape in the pressing step.
  • the low heat conduction portion forming step includes a filling step of filling the concave portion provided on the combustion chamber side of the crown portion with the low heat conduction portion forming material, and a plurality of rotating the low heat conduction portion forming material in the concave portion. Pressing with the tool at the same time. Thereby, in the mixed pressing step, the meat of the piston between the recesses is difficult to escape, and it is possible to easily apply pressure to the low heat conduction portion forming material with the tool.
  • the low thermal conduction portion forming step includes a filling step of filling the concave portion provided on the combustion chamber side in the crown portion with the low thermal conduction portion forming material, and a tool for rotating the low thermal conduction portion forming material in the concave portion.
  • a pressing step of pressing with, The pressing step is performed in a state where the outer peripheral side of the main body is surrounded by a mold. Thereby, a deformation
  • the piston A piston of an internal combustion engine, formed of an aluminum alloy, and having a crown portion, and a skirt portion provided on the crown portion, a main body portion, An annular low heat conduction part formed of a low heat conduction part forming material which is provided on the combustion chamber side of the internal combustion engine of the crown part and has a lower thermal conductivity than the aluminum alloy; A non-low heat conduction portion that is provided on the inner side of the inner peripheral edge of the annular low heat conduction portion and is formed of a material having a higher thermal conductivity than the low heat conduction portion forming material.
  • the low heat conduction part has a plurality of parts to be stirred having a stirring locus in which the low heat conduction forming member is stirred around a stirring center in a cross section orthogonal to the moving direction of the piston.
  • a plurality of low heat conduction parts can be formed, and a low heat conduction part having an appropriate shape can be formed at an appropriate position according to the fuel injection region.
  • the low heat conduction part forming material is a material having a higher hardness than the aluminum alloy
  • the crown portion has a ring groove provided on an outer peripheral side of the crown portion and into which a piston ring is inserted, and the low heat conduction portion is provided in a range including the ring groove.
  • the low heat conduction part forming material is a mixed powder material.

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  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • Pistons, Piston Rings, And Cylinders (AREA)

Abstract

L'invention concerne un procédé de production de piston destiné à un moteur à combustion interne qui, afin de fournir un procédé de production d'un piston avec lequel un élément à faible conduction thermique peut être fourni à une position correspondant à une région d'injection de carburant du piston, est conçu pour avoir une étape de formation de partie à faible conduction thermique dans laquelle une partie annulaire à faible conduction thermique, qui est formée à partir d'un matériau de formation de partie à faible conduction thermique, qui est un matériau ayant une conductivité thermique plus basse qu'un alliage d'aluminium, est formée sur un côté chambre de combustion de moteur à combustion interne d'une partie de couronne d'une partie de corps principale de piston, la partie à faible conduction thermique étant formée de façon à avoir une partie qui n'est pas à faible conduction thermique, qui est formée à partir d'un matériau ayant une conductivité thermique plus élevée que le matériau de formation de partie à faible conduction thermique, davantage vers l'intérieur que le bord périphérique interne de la partie annulaire à faible conduction thermique dans une coupe transversale qui est orthogonale à la direction de déplacement du piston dans un cylindre du moteur à combustion interne.
PCT/JP2016/086692 2016-01-13 2016-12-09 Procédé de production d'un piston, et piston WO2017122474A1 (fr)

Applications Claiming Priority (2)

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JP2016-004731 2016-01-13
JP2016004731A JP2017125440A (ja) 2016-01-13 2016-01-13 ピストンの製造方法およびピストン

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WO2017122474A1 true WO2017122474A1 (fr) 2017-07-20

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Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS59111918U (ja) * 1983-01-18 1984-07-28 トヨタ自動車株式会社 直接噴射式デイ−ゼル機関
WO2015016122A1 (fr) * 2013-08-01 2015-02-05 日立オートモティブシステムズ株式会社 Méthode de fabrication d'un piston pour moteur à combustion interne, et piston pour moteur à combustion interne
JP2015094292A (ja) * 2013-11-12 2015-05-18 トヨタ自動車株式会社 内燃機関
JP2015169193A (ja) * 2014-03-11 2015-09-28 日産自動車株式会社 内燃機関のピストン

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS59111918U (ja) * 1983-01-18 1984-07-28 トヨタ自動車株式会社 直接噴射式デイ−ゼル機関
WO2015016122A1 (fr) * 2013-08-01 2015-02-05 日立オートモティブシステムズ株式会社 Méthode de fabrication d'un piston pour moteur à combustion interne, et piston pour moteur à combustion interne
JP2015094292A (ja) * 2013-11-12 2015-05-18 トヨタ自動車株式会社 内燃機関
JP2015169193A (ja) * 2014-03-11 2015-09-28 日産自動車株式会社 内燃機関のピストン

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