JP2002539357A - Method of manufacturing a piston for an internal combustion engine - Google Patents

Abstract

  (57) [Summary] The piston manufacturing method manufactures a piston of an internal combustion engine. The method forges a billet from an initial billet comprising an aluminum alloy consisting of silicon, intermetallic particles, and injection hardened particles, wherein the forging comprises at least one of superplastic and hot deformation conditions, ie, heat treatment of the forged billet. It is implemented below. Forging is about 0.8T _melt~ About 0.98T_meltForging at temperatures in the range of Forging is also about 5 × 10^-2/ Sec to about 5 × 10^-FiveIncluding forging at a strain rate in the range of / s. The piston is formed with a profile that allows other parts to be connected to the piston. The initial billet includes coarse silicon having at least one lamellar overall shape, intermetallic particles, injection hardened particles, and at least one of spherical fine silicon, intermetallic particles, injection hardened particles. The volume content of silicon, intermetallic, and injection-hardened particles ranges from about 25% to about 60%, and the average particle size of silicon, intermetallic, and injection-hardened particles is about 15 μm.^TwoIs less than.   

Description

DETAILED DESCRIPTION OF THE INVENTION

BACKGROUND OF THE INVENTION The present invention includes, but is not limited to, pistons for internal combustion engines used in automotive engines, tread or crawler machines, aviation engines, and marine engines. And the manufacture of pistons for internal combustion engines.

[0002] Pistons are generally high stressed engine components. While the piston is moving, the top or crown of the piston may experience high temperatures. Any grooves formed in the piston, for example for the compression ring, may be subjected to high impact stress. In addition, if the piston has a wrist pin port, this port may be subjected to harmful cyclic loading. These piston mechanisms
Changing operating stress, load, temperature, and other operating characteristics (hereinafter "operating characteristics"
), Resulting in different piston sections that require different mechanical attributes and qualities (also referred to as "piston properties") to withstand these operating characteristics.

[0003] The mechanical properties of a piston may be determined by its properties. Pistons, such as, but not limited to, internal combustion pistons in engines, often include aluminum alloys. These aluminum alloys include, but are not limited to, silmine containing silicon in the range of about 11% to about 35%. In addition, if the piston includes a silumin alloy-based compound, the piston may also include a hardener such as silicon carbide (SiC) or aluminum oxide (Al ₂ O ₃ ). The silicon and intermetallic particles in the alloy can work with the hardeners described above to enhance the heat resistance and wear characteristics of the material. However, a material's resistance to metal fatigue and plasticity decreases with increasing heat resistance and wear properties.

[0004] If the piston's base material does not provide the piston with the desired properties, the stressed area of the piston can be formed from a hardened material. Hardening can be performed by incorporating at least one of an iron-based alloy and a ceramic material. For example, the piston portion can include an iron holder that is generally accepted as heat resistant, which can reduce wear of the compression ring grooves. The piston portion may be reinforced by plasma arc welding and injecting alloy components such as nickel, iron, and other such reinforcing components to the piston.
The heat resistance of these materials protects the piston.

[0005] The design and manufacture of the piston depends on the desired use of the piston. For example, Yu et al., "Alluminum Alloys in Tractor Building"
"(Aluminum alloys in tractor manufacturing) (Machine Buildi
ng, 1971), the piston can be formed by casting. This casting method offers a relatively efficient and inexpensive manufacturing method that allows casting of pistons with reinforcements. Such reinforcements include, but are not limited to, piston ring holders and brackets. However, these aluminum cast pistons are generally used where low dynamic loads (pressure) are applied, as only low levels of mechanical stress can be applied.

[0006] Other well-known piston manufacturing methods include Yu et al., "Isothermal F."
"Orging of Pistons from an Alloy" (Isothermal forging of pistons from alloys) (Forging Production Magazine 1979)
For example, there is a hot deformation forging from an aluminum alloy billet as disclosed in U.S. Pat. Although this forging method is more expensive than the casting method, the forging of the silumin alloy piston has enhanced mechanical properties. For this reason, this sirmine alloy piston can be used for applications that receive a heavy load. Since the plasticity of silumin is low under hot deformation forging conditions, forging is generally performed on small, relatively simple pistons. Thus, reinforcements can be added to overcome this lack of plasticity, for example, by mounting a bracket on the piston. This reinforcement can complicate piston design and increase manufacturing costs. Additionally, forging methods may be limited by forging temperatures that do not provide the desired quality and size of silicon and other hardened particles in the silumin alloy. Thus, with known forging methods, sirmine alloy pistons do not achieve the desired plasticity and mechanical properties. Therefore, there is a need for a piston manufacturing method capable of manufacturing a piston having desired plasticity and mechanical properties. Further, there is a need for a piston manufacturing method that overcomes the above deficiencies.
There is also a need for a piston manufacturing method for manufacturing a sirmine alloy piston.

(Summary of the Invention) A piston manufacturing method manufactures a piston of an internal combustion engine. The method forges a billet from an initial billet comprising an aluminum alloy consisting of silicon, intermetallic particles, and injection hardened particles. Forging is performed under at least one of superplastic conditions and hot deformation conditions, ie, heat treatment of the forged billet. Forging is about 0.8
Including forging at a temperature in the range of T _melt ~ about 0.98T _melt. Forging is also
Including forging at a strain rate ranging from about 5 × 10 ⁻² / sec to about 5 × 10 ⁻⁵ / sec. The piston is formed with a profile that allows other parts to be connected to the piston. The initial billet comprises at least one of coarse-grained silicon, intermetallic particles, injection-hardened particles, and at least one of spherical fine silicon, intermetallic particles, injection-hardened particles, including at least one lamellar shape. . The volume content of silicon, intermetallic, and injection hardened particles ranges from about 25% to about 60%, and the average particle size of the silicon, intermetallic, and injection hardened particles is less than about 15 μm ² .

[0008] The above and other aspects, advantages and salient features of the present invention will become apparent from the following detailed description which discloses embodiments of the invention with reference to the accompanying drawings. In the drawings, similar parts are designated by similar reference characters throughout the drawings.

Description of the Invention [0009] The method of making a piston and its associated system implemented according to the present invention allow for the manufacture of a piston containing a silumin alloy. In this piston manufacturing method, a piston can be formed by forging. Sirmine alloy pistons manufactured by forging performed according to the present invention include various mechanical properties and features combined into one piston. These mechanical properties and characteristics further depend on the initial external configuration and microstructure of the Silumin alloy piston. Further, the mechanical properties and characteristics also depend on the external configuration and microstructure of the sirmine alloy piston caused by the deformation process in the piston manufacturing method performed according to the present invention.

[0010] A piston manufacturing method implemented according to the present invention is schematically illustrated by the piston die system of FIG. In FIG. 1, the piston die system includes a piston die matrix 1, a piston die 2
, Pusher 3, heating element 4, at least one liner plate 5, billet 6
, And a forged piston 7. FIG. 2 also illustrates the features of the piston die system and related structures of the piston manufacturing method performed by the present invention. FIG. 2 shows a ring holder 8, a spring 9, a piston die master guide 10, a piston billet 11 with a ring groove, a piston blank, a ring holder, and a crown 12.
, And a piston including a ring holder 13. FIG. 3 shows a molten material 14 formed by a piston manufacturing method implemented according to the present invention.

Further features of the piston die system and associated structures are shown in other figures. These features include an alignment flange 15, a partially formed billet inner portion 16,
A ring 17, a band-shaped ring holder 18, a cup-shaped billet outer case 19, a cup-shaped billet inner case 20, a washer-shaped outer billet case 21, and a washer-shaped inner billet case 22 are included.

A method for producing a sirmine alloy piston implemented in accordance with the present invention produces a sirmine alloy piston by forging a fully formed piston that includes a structural reinforcement function (hereinafter “reinforcement”). be able to. Reinforcements include, but are not limited to, ring holders and piston brackets. The piston manufacturing method implemented by the present invention is used to form pistons of various dimensions for internal combustion engines, such as those used in automotive, aviation and marine applications, and large machines with treads. be able to. The method of manufacturing a piston can improve piston manufacturing efficiency by providing a piston having mechanical properties and characteristics that satisfy the desired mechanical properties and characteristics of the intended application.

[0013] The method of manufacturing a piston performed by the present invention includes forging a billet including an aluminum alloy component. The aluminum alloy composition includes at least one of silicon, intermetallic particles, and injection hardened particles. The following description of the invention refers to the aluminum alloy composition described above, but other compositions are also within the scope of the invention. The particles can be prepared as a thin profile configuration. The composition of the initial billet, for example, the aluminum alloy composition, may also include at least one of finely divided silicon, intermetallic particles, and injection hardened particles. The injection-cured particles can have a generally spherical outer shape.

[0014] Following the forging step of the piston manufacturing method, a heat treatment step may be continued. In the piston manufacturing method implemented by the present invention, a large-sized piston and a piston including a reinforcement can be manufactured. The method of manufacturing a piston also allows the piston to be formed into a profile that allows the piston component to be easily connected to the piston. Forging generally involves reducing the piston material from about 0.8 T _melt to about 0.5 T _melt .
It is performed in a temperature range of 98T _melt . The forging of the piston manufacturing process is generally performed at a strain rate ranging from about 5 × 10 ⁻² / sec to about 5 × 10 ⁻⁵ / sec.

[0015] The piston manufacturing method also includes a forging step performed under superplastic conditions or normal hot deformation conditions. These conditions are generally such that at least one of the silicon, intermetallic particles, and the injection hardened particles has a volume content ranging from about 25% to about 60% of the aluminum alloy composition, and the silicon, intermetallic particles, And when the average particle size of the injection cured particles is less than about 15 μm ² . If the billet material composition includes a particle content and particle size outside the above ranges, forging can be performed under hot deformation conditions. Thus, a larger silicon or particle size can provide a forging step with a lower strain rate. For example, forging a strain rate in the range of about ^10-3 / sec to about 5 x ^10-5 / sec and a lower forging temperature range, e.g., a temperature range of about 0.83T _melt to about 0.89T _melt. can do.

In determining the parameters of the piston manufacturing method, the characteristics of the billet material composition and the external configuration can be considered. For example, if the billet material composition includes a particle weight content of about 20% or more and an average particle size of 15 μm ² or more, consider the initial billet geometry and billet placement in the forging equipment for piston manufacture. Can be. These billet material composition and profile features can also reduce the deformation that occurs during the performance of the piston manufacturing method practiced by the present invention. A piston manufacturing method that can include forging as described above can also include a single step. The piston manufacturing method including the one-step process can be performed under hot deformation conditions and superplastic conditions.

Alternatively, the piston manufacturing method is performed in a temperature range from about 0.90 T _melt to about 0.98 T _melt with a strain rate range from about 5 × 10 ⁻² / sec to about 10 ⁻³ / sec. be able to. These temperature ranges and strain rate ranges are employed by a piston manufacturing method using a billet material composition comprising at least one of silicon, intermetallic particles, and injection hardened particles having an average particle size of less than 6 μm ² . In the method of manufacturing a billet piston having such a billet material composition, the billet can undergo primary deformation before the forging step. Primary deformation is about 0.79T _melt to about 0.86
In the T _melt temperature range, it can occur at a strain rate range of about 5 × 10 ⁻⁴ / sec to about 5 × 10 ⁻³ / sec.

[0018] Alternatively, the method of manufacturing a piston implemented according to the present invention may be from about 6 μm ² to
A piston can be formed from a billet comprising a billet material composition having at least one of silicon, intermetallic particles, and injection-hardened particles of an average particle size having a particle size in the range of about 15 μm ² . Units per million of this billet material composition (ppm
) May include hot deformation forging performed in a temperature range from about 0.84 T _melt to about 0.96 T _melt at a strain rate range from about 10 ⁻³ / sec to about 5 × 10 ⁻⁴ / sec. it can.

Yet another alternative to the piston manufacturing method implemented by the present invention is that the
Including at least one of silicon, intermetallic particles, and injection-hardened particles having an average particle size of less than μm ² , the injection-hardened particles can form a piston from a billet having a generally spherical profile. In this aspect of the piston manufacturing method practiced by the present invention, the volume percentage of silicon particles, intermetallic particles, and injection hardened particles is in the range of about 25% to about 60%. With such a billet material composition, the piston manufacturing method can be performed in a temperature range of about 0.88T _melt to about 0.98T _melt ,
Including forging performed under superplastic conditions in a strain rate range of about 5 × 10 ^-5 / sec to about 1 × 10 ^-1 / sec.

Still further, a method of making a piston comprises forming a piston from a billet having a billet material composition comprising at least one of silicon, intermetallic particles, and injection hardened particles in a volume of less than about 15% of the total billet mass. Can be. This method of manufacturing a piston, as practiced by the present invention, can use a billet material that can have a generally tapered conical profile. Billets that can be cast materials
The billet material composition has a profile configuration in which contact between the billet and the piston die master is achieved only by side surfaces that are about 30% or more of the area of the billet.

In the method of manufacturing the piston, a gap may be formed between the lower end of the billet and the base of the piston die. The gap interval can be determined by the external configuration of the billet material. For example, the gap spacing can be determined with respect to the size and content of at least one of silicon particles, intermetallic particles, and injection hardened particles. This gap interval is generally expressed by the following equation. h = dK / C√F where d is the inner diameter (mm) of the bottom of the piston die matrix, C is the content (% by mass) of at least one of silicon, intermetallic particles, and injection hardened particles, and F is silicon The average area (μm ² ) of at least one of the particles, the intermetallic particles, and the injection hardened particles, and K is a coefficient that reflects the shape and size of the forged piston die bit, typically from about 0.5 to Given in the range of about 10. Therefore, the average particle size is about 15
In billets containing silicon, intermetallic particles, and injection-hardened particles less than μm ² , any deformation is generally performed at a constant temperature essentially equal to the quench temperature. Any quenching immediately after the deformation step can achieve the piston manufacturing method.

If the billet contains silicon, intermetallic and injection hardened particles having an average particle size of less than 15 μm ² and contains less than 15% of silicon, intermetallic and injection hardened particles, the particle size is 20 μm ^The ring holder can be made from an alloy containing about 20% to about 45% by volume of the silicon, intermetallic particles, and injection hardened particles.
Furthermore, the ring holder of the piston manufacturing method implemented by the present invention can be attached to the base end of the piston die matrix surface by an interference fit over the piston side. Thus, any hot deformation forging can be performed,
As a result, the piston crown is shaped first and then inside.

The method of making a piston practiced according to the present invention includes silicon, intermetallic particles, and injection-hardened particles having an average particle size of less than about 15 μm ² and a content of about 25% to about 60% by volume. It can be used in billet material compositions. In this combination, using a ring holder comprising an alloy having an average particle size of less than about 20 μm ² and having a content of about 20% to about 45% by volume silicon, intermetallic particles, and injection hardened particles. Can be. If the ring holder is mounted on the piston side by an interference fit and placed against the base end of the piston, the forging step can be performed under superplastic conditions. Thus, the piston crown can be shaped and then the interior of the piston.

A billet containing silicon, intermetallic particles, and injection hardened particles having an average particle size of less than about 15 μm ² , and containing about 15% silicon, intermetallic particles, and injection hardened particles, is made of pig iron or steel. Ring holders can be used. In addition, the ring holder can be mounted on the piston for such a billet by an interference fit over the piston side against the open end of the piston die matrix surface. Any piston forging in the piston manufacturing method performed by the present invention can be performed under superplastic conditions. Thus, the piston crown can be shaped first and then the interior of the piston.

Billets containing silicon, intermetallic particles, and injection-hardened particles having an average particle size of less than about 15 μm ² , and containing silicon, intermetallic particles, and injection-hardened particles in a range of about 25% to about 60%, , A ring holder made of pig iron or steel can be used. In addition, the ring holder can be mounted by means of an interference fit on the piston side against the open end of the piston die master in the piston for this type of billet. Any piston forging in the piston manufacturing method performed by the present invention can be performed under superplastic conditions. Thus, the piston crown can be shaped first and then the interior of the piston.

Another aspect of the invention may provide an alignment surface for the ring holder and the piston body billet including a conical shape. The conical shape can be at an angle ranging from about 1 ° to about 10 °. The body billet can be made of a ring shoulder having a negative angle ranging from about 1 ° to about 3 °. Ring holder is about 0.1mm in diameter
An interference fit size in the range of 約 0.2 mm allows it to be placed in the ring shoulder. The positioning of the ring holder is generally performed at room temperature in the piston manufacturing method implemented according to the invention.

The method of manufacturing a piston including forging can be performed in two steps. In a first step, forging may include placing the ring holder in a piston die matrix. In the post-placement step, an interference fit is provided between the outer surface of the ring holder and the inner surface of the piston die. The interference fit can be calculated as follows. 1.0017 ≦ d / D ≦ 1.035 where d is the outer diameter of the ring holder at the forging temperature, and D is the inner diameter of the piston die matrix at the forging temperature. Forging can be performed by physically moving the piston-die matrix in the forging direction and fixing the ring holder during the subsequent forging of the piston crown.

The ring holder in the method of manufacturing a piston implemented according to the invention can be coated with a layer of an alloy containing aluminum. Coating and piston
The cases can be made from essentially the same composition.

With the piston manufacturing method implemented according to the present invention, two billets can be used to forge a piston having an inner case and an outer case. For example, but not a limitation of the present invention, a billet for a piston manufacturing method can include about 15% (in total) silicon, intermetallic particles, and injection hardened particles. This billet can be used to make the outer case of the piston. Another example billet also includes about 15% (in total) silicon, intermetallic particles, and injection cured particles. This billet material composition can be used to make the inner case of the piston, and the outer case can be attached to the side surface of the piston by an interference fit.

A method of making a piston, including forging two billets, involves forming a billet having an exemplary billet material composition comprising from about 45% to about 60% by volume (total) silicon, intermetallic particles, and injection hardened particles. Can be used. This billet material composition can be used to make the outer case of the piston. Silicon, intermetallic particles,
An exemplary billet material composition comprising (in total) from about 25% to about 40% by volume of injected hardened particles can be used to make the inner body of the piston. While forging such a piston, the piston die can be heated to a temperature that promotes deformation of the inner billet, such as under superplastic conditions. The piston-die matrix can be heated under superplastic conditions to a temperature that promotes deformation of the outer billet. In addition, this piston manufacturing method can generally use a billet in the form of a washer. Alternatively, a piston manufacturing method involving forging of two billets may use a cup-shaped billet having an outer cup-shaped billet including a tapered portion at the base end of the billet. In a piston manufacturing method involving forging of two billets, the composite billet assembly embodied in the present invention can be completed by pressing the inner cup into the outer cup.

A billet for a piston manufacturing method practiced according to the present invention may include a ridge, shoulder, or other extension. The surface of the shoulder may include a corrugated surface having a wave period L (FIG. 6). Billet material compositions with increased silicon, intermetallic particles, particle size, and injection hardened particles result in increased wave period L.
For example, a piston manufacturing method implemented according to the present invention may further use steel washers, spacers, or other separating devices. The spacer can be placed on the shoulder surface. The thickness of the washer generally satisfies the following conditions. L / l = 4-42 Further, the relationship between billet height and shoulder can be determined such that the corrugated washer can be at the same overall level in the compression ring groove of the piston when forging is achieved.

A billet comprising silicon, intermetallic particles, and injection-hardened particles having an average particle size of less than about 15 μm ² can be placed in a piston-die matrix opposite a bracket, wherein the bracket has reflect. This orientation results in the formation of a forged lock joint, for example using hot deformation, after the piston has been forged. The bracket surface area S created in the formed lock joint can be determined by the following equation: S = KP / SinαF where P is the separation force required to overcome the dynamic force created during engine operation, K
Is the reliability factor, F is the fluid resistance of the aluminum alloy at the working temperature, and α is the angle between the shoulder and the direction of piston movement.

[0033] Alternatively, silicon, intermetallic particles, and injection cured particles having an average particle size of less than about 15 μm ² , including silicon, intermetallic particles, and injection cured particles in the range of about 25% to about 60%. A billet containing the entire volume can be placed in a piston die matrix during the piston manufacturing process performed according to the present invention. This arrangement may include placing it opposite a bracket reflecting the billet surface. This arrangement results in the formation of a lock joint after the piston has been forged under superplastic conditions. The surface area S of the bracket can be determined by the following equation as described above. S = KP / SinαF

Another alternative is to include silicon, intermetallic particles, and implant hardened particles having an average particle size of less than about 15 μm ^2, with silicon, intermetallic particles, and implants ranging from about 25% to about 60%. A billet containing the entire volume of the cured particles can be placed in the piston die master opposite the bracket. The bracket can be formed from a porous ceramic material, such as a porous ceramic material impregnated with an aluminum alloy. Porosity of the porous ceramic material ranges from about 35% to about 50%. Therefore, forging in the piston manufacturing method performed by the present invention can be performed under superplastic conditions. To infiltrate the porous ceramic material, the same aluminum alloy composition used to make the piston case can be used.

After the forging step, the piston formed by the piston manufacturing method implemented according to the present invention may be subjected to further deformation. For example, a further deformation is to deform in a closed end piston die at a strain rate in the range of about ^10-5 / sec to ^10-4 / sec for a time in the range of about 0.5 to about 5 minutes. including. Average particle size is about 15μ
For billet material compositions that include silicon, intermetallic particles, and injection cured particles that are less than m ² , a cured layer can be deposited on the piston surface. In this scenario, hot deformation forging is performed in a temperature range of about 0.9T _melt to about 0.96T _melt ,
Strain rates ranging from about 5 × 10 ⁻² / sec to about 10 ⁻³ / sec can be performed.

The piston manufacturing method implemented by the present invention can enhance forging conditions in manufacturing a piston. This enhancement can be achieved by considering the initial microstructure and chemical composition of the billet. Experiments have shown that the desired forging temperature interval is provided to produce the desired mechanical properties. Forging of large and complex billets can be achieved at the above-mentioned temperature and strain rate intervals while performing the technique of placing a billet on a piston die implemented by the present invention.

[0037] Pistons, such as simple shaped pistons that have not been cured or have no added reinforcement elements, can be employed in low rated engines. These pistons
In still another piston manufacturing method implemented by the present invention, the piston can be manufactured by die casting from a billet. This piston manufacturing method can manufacture a piston whose manufacturing cost is relatively low. Casting is the least expensive method in billet manufacture. The raw materials for mold casting can include a coarse microstructure including silicon and intermetallic particles having an average particle size of about 15 μm ² or more.

For example, silmins containing this microstructure generally exhibit a low level of plasticity under hot deformation conditions. These sirmines are also available from about 0.86T _melt to about 0.91.
It exhibits high plasticity in the temperature range of T _melt and in the strain rate range of about 10 ⁻³ / sec to about 5 × 10 ⁻⁵ / sec. Fine-grained sirmine with particles having an average particle size of less than about 6 μm ² exhibits higher plasticity and is suitable for use in the production of pistons of complex shape and large pistons. If the piston manufacturing method includes a pre-forged billet having this microstructure, continuous casting and hot deformation forging can be performed, for example, by a compression step. Decreasing the size of the alloy particles allows for an increase in the deformation temperature range. The temperature and strain rate at which the deformation forging is performed in the piston manufacturing process will affect the mechanical properties of the silumin material. These affected properties can be recognized after the forging step of the piston manufacturing method, followed by a heat treatment.

The method of manufacturing a piston implemented by the present invention can manufacture a piston from an alloy having a fine-grained microstructure. This fine-grained microstructured alloy has a temperature range of about 0.9 T _melt to about 0.96 T _melt and a strain rate range of about 5 × 10 ⁻² / sec to about 1 × 10 ⁻³ / sec after deformation. And the desired mechanical properties can be exhibited. These properties formed in the above ranges can be attributed to the formation of micropores adjacent to silicon, intermetallic particles, and injection-hardened particles in the billet material. The micropores can be formed under the high temperature deformation conditions of the piston manufacturing method. The size of the micropores can be increased by reducing the strain rate applied during the piston manufacturing process. This reduction can be attributed to the mechanical properties achieved at the high strain rates implemented by the present invention.

Conversely, the present piston manufacturing method can also manufacture a piston from an alloy having a coarse-grained fine structure. It has been determined that alloys with a coarse-grained microstructure can exhibit desired mechanical properties after deformation in a strain rate range of about ^10-3 / sec to about 5 x ^10-5 / sec. Furthermore, the silicon having an average particle size of about 6 [mu] m ² 15 m ^2, deformation condition of the billet material composition comprising intermetallic particles, and the injection cured particles were determined. These deformation conditions include a temperature range of about 0.84 T _melt to about 0.96 T _melt and about 10 ⁻³ / sec to about 5 × 1.
Includes deformation in the strain rate range of 0 ^-5 / sec.

A fine grain alloy for a piston manufacturing process comprising silicon, intermetallic particles, and injection hardened particles having an average particle size of less than about 6 μm ^{2 in a} billet is used to form a cast billet comprising a coarse thin layer microstructure. It can be manufactured by hot deformation. The conditions of the piston manufacturing method for deforming and forging such silicon and intermetallic particles are as follows: a temperature range of about 0.79 T _melt to about 0.96 T _melt , and about 5 × 10 ⁻⁴ / sec to about 5 × 10 ⁴ _melt. ^In the strain rate range of ^-3 / sec.

The piston manufacturing method practiced by the present invention can be used to manufacture pistons with various compositions, microstructures, and particle sizes under superplastic conditions. For example, this is not a limitation of the present invention, but fragile materials, such as eutectic sirmine reinforced with hardened particles, can be made by the piston making method implemented according to the present invention. Alternatively, a piston hardened with a low stress flow material, which has a complex shape and reduces the deformation and displacement of the ring holder relative to the piston itself, can be manufactured by the piston manufacturing method implemented according to the present invention. it can. As yet another alternative, a piston containing large grain sizes pressed by a low-strength press can be formed by the present piston manufacturing method.

The superplastic deformation conditions of the piston manufacturing method practiced by the present invention can be used for silicon, intermetallic particles, and injection hardened particles having an average particle size of less than about 15 μm ² . Further, the superplastic deformation conditions include silicon, intermetallic particles, and injection hardened particle volumes in the range of about 25% to about 60%. About 5 × 10 ^-5 / sec to about 5
A strain rate range of × 10 ^-3 / sec and a deformation temperature range of about 0.88 T _melt to about 0.98 T _melt can be used as superplastic deformation conditions for the above particle size.

The method of making pistons practiced according to the present invention can forge billets containing about 15% by weight or more of silicon, intermetallic particles, and injection hardened particles, all having an average particle size of about 15 μm ² or more. . Such billet material compositions generally exhibit a low level of plasticity. During the present piston manufacturing process, the contact between the piston billet and the surface of the piston die master is from about 30% to about 100% of the side surface area until the piston die bit contacts the original end. Should occur within. This contact should prevent at least one of the crevice formation upon cleavage of the billet.

Further, the present piston manufacturing method should provide a maximum spacing between the billet base and the piston die matrix base. This spacing generally depends, for example, on the plasticity of the billet material composition, but is limited to at least one of the amount and size of silicon, intermetallic particles, and injection hardened particles, the diameter of the billet, and the size and shape of the piston die. Not something. If the billet material composition is brittle, the spacing between the base of the piston billet and the base of the piston die matrix can be further reduced. This spacing is necessary to prevent warping of the billet when the piston die bit is placed in the piston die matrix.

The method of making a piston implemented according to the present invention may include quenching cooling after forging has been completed if the piston is forged at essentially the same temperature for quenching. This procedure reduces the time of the piston manufacturing process and therefore can be omitted, since the heating for the quenching step is longer. Furthermore, the absence of "quenching heating" can prevent crystal growth during solidification of aluminum in the billet material composition. This procedure can also provide a finer grain microstructure in the final piston.

To limit the collapse of the piston ring groove during operation of the engine, the ring groove in the piston can be reinforced in the piston manufacturing method. The ring groove can be reinforced with a metal ring holder, which provides a strength generally higher than that of the billet material at the operating temperature. For example, if the piston is formed as a casting, the ring holder may typically include pig iron reinforced by a coating formed by molten metal. As an alternative,
When the piston is forged, the ring holder is finely divided, including silicon, intermetallic particles, and coarse sirmine with injection hardened particles, because sirmine generally has higher strength properties than piston billet material. Structures can be included.

For example, fine-grained sirmine having silicon, intermetallic, and injection-hardened particles having an average particle size of less than about 15 μm ² and containing less than about 15% by volume of silicon, intermetallic, and injection-hardened particles. The intermediate material can be used in a piston manufacturing method implemented according to the present invention. This material exhibits plasticity that can allow forging with a ring holder formed from silumin. The silumin can comprise from about 20% to about 45% silicon, intermetallic, and injection-hardened particles, with an average particle size of about 20 μm ² of silicon, intermetallic, and injection-hardened particles.

The ring holder can be placed on a billet and placed with the billet in a piston die matrix. An interference fit can be established between the piston billet surface and the base end of the piston die mold so that the blank does not crack. First, a piston crown can be formed to place the ring holder on the billet to prevent deformation. The stress on billet material is generally
Less than the stress applied to reinforce the ring holder material during any hot deformation process. Therefore, the reinforcing material fills the space around the ring holder,
The holder typically experiences a minimum deformation of, for example, less than about 20%. Billet has about 25 particles
Piston billets having a "fine duplex structure", which means comprising a billet material composition having from about 60% to about 60% by volume, can be subjected to a method of making a piston carried out according to the present invention under superplastic conditions. . In this piston manufacturing method,
Forging is performed by a press, and the deformation of the ring holder is small.

A ring holder comprising at least one of pig iron and steel, wherein the average particle size of silicon, intermetallic particles, and injection hardened particles is less than about 15 μm ² , is used in the present piston manufacturing method to form a ring holder. Of the ring holder can be prevented, and deformation or destruction of the ring holder can be prevented. To achieve this prevention, a ring holder can be inserted into the die end surface into a piston die master having an interference fit on the side surface. Forging is simplified by first forging the piston crown and then forging the inner part of the piston under superplastic conditions.

In the piston manufacturing method implemented according to the present invention, a reliable joint must be formed between the ring holder and the piston. Such a joint can be made by a piston material that fills the cavity of the ring holder,
The deformation of the joint then follows. If the oxide film is provided on a ring holder, such as by pre-treatment, peeling of the film occurs when the ring holder is placed on the piston blank. Approximately 1 ° -1
It can be conical with a cone angle in the range of 0 °. The piston and billet ring shoulder can include negative angles ranging from about 1 ° to about 3 °. In addition, the ring holder is about 0.1 mm at a temperature ranging from about 15 ° C. to about 540 ° C.
It can be compressed with an interference fit having a diameter in the range of about 0.2 mm. The forging conditions implemented by the present invention can create a reliable diffusion bond between the ring holder and the piston. The negative angle prevents the mating end of the ring holder and the engagement surface of the piston billet from oxidizing during heating and forging. Since the lower end of the ring holder and the ring shoulder are different in shape, a closed cavity can be formed. In addition, contact between these surfaces and the furnace atmosphere is prevented, which can reduce the rate of oxidation of the piston billet and ring holder during forging.

Furthermore, because of the different shapes, it is possible for deformations in the ring holder base and the shoulder to occur during forging. Deformation can reduce oxides and promote the formation of a diffusion bond between the ring holder base and the shoulder surface.

Forging a piston with a ring holder can be performed in a two-stage piston manufacturing method. First, the billet can be placed with the base end facing the piston die with the ring groove zone facing upward. Piston die
The crown is embossed and then the ring holder is compressed. The piston blank can then be inverted so that the crown is facing down and the second piston manufacturing stage begins with the formation of the piston inside.

The ring holder can be placed in a piston die master, thereby forming an interference fit between the outer surface of the ring holder and the inner surface of the piston die master. This arrangement can prevent the ring holder from cracking while the piston undergoes a hot deformation process. This arrangement can also prevent distortions caused by changes in metal flow during formation of the piston interior. The characteristics of the interference fit can be calculated as follows. 1.0017 ≦ d / D ≦ 1.0035 where d is the outer diameter of the ring groove at the forging temperature, and D is the piston diameter at the forging temperature.
This is the inner diameter of the die matrix.

If the interference fit is smaller than desired, cracking or warping of the ring holder may occur. A narrow interference fit can complicate the insertion of the piston billet with the ring holder into the interior of the piston die master. If the piston manufacturing method places the ring holder on a cylindrical billet with little or no gap between them, the piston die mold is used in the piston manufacturing method implemented by the present invention. -The stability of the holder can be enhanced. This orientation can also prevent uneven metal distribution above and below the ring holder. This orientation, together with the ring holder position during forging, can provide a stable platform for the ring holder.

Aluminum can also be metal infiltrated onto the ring holder. Metal infiltration at elevated temperatures can provide aluminum, for example, an aluminum alloy through a steel ring holder. This procedure may also remove oxide films from the surfaces of the aluminum alloy piston and ring holder. To enhance the stability of the joint between the piston case and the ring holder, any alloy used in the piston manufacturing method implemented according to the invention, e.g. for coating, should have similar or otherwise similar wires. Must have an expansion coefficient.

The two-layer piston configuration, and the piston manufacturing method used to form such a two-layer piston configuration, can provide reliable piston performance during initial engine startup. A two-layer piston configuration can also provide increased reliability when the engine is stressed at high temperatures. Silicon, intermetallic particles,
A two-layer piston configuration with a high content of injected hardened particles can provide the desired strength properties at operating temperatures. However, at low temperatures, such as when the engine is first started, the materials used for the two-layer piston construction may provide a low level of plasticity. However, a two-layer piston configuration having a low content of silicon, intermetallic particles, and injection-hardened particles and having a high level of plasticity can provide fatigue resistance.

During start-up and warm-up of the engine, the two-layer piston configuration is capable of transmitting wrist pin forces into the interior of the piston. The interior of the piston can be formed from an alloy with a low content of silicon, intermetallic particles, and injection hardened particles. Engines having pistons formed by the piston manufacturing method practiced in accordance with the present invention are in operation in a range of about 250 ° C. to about 350 ° C. and, if fully stressed, in a ring groove zone. Temperature can be achieved. The alloy of the piston outer case is a composition with a high content of silicon, intermetallic particles, and injection hardened particles that prevents at least one of the piston rings from breaking the piston ring groove and that the piston base has a high operating temperature. Can prevent burning.

Variations in piston thickness can be determined to enhance the characteristics of the piston manufacturing process, the wear resistance, and the plasticity of the piston. For example, the working temperature while the engine is running around the lower edge of the piston should be lower than the temperature in the ring groove zone. During a cold start of the engine, the lower edge of the piston skirt may experience impact stress as the piston moves from top dead center to bottom dead center. This stress can cause the lower edge of the piston skirt to include materials that are highly plastic and have sufficient wear resistance. These features are obtained by minimizing the thickness of the outer piston body. If the plasticity is sufficient for forging, the piston billet can be washer-shaped (as described above) because the washer shape is conductive to forging. Conversely, if the plasticity of the alloy is not sufficient for forging or compression, the piston billet can be cup-shaped.

Assembling the composite piston billet prior to forging facilitates removal of the oxide film covering the contact points of the inner and outer cases. This includes press fitting the inner case into the outer case. An exemplary forging step for manufacturing a diffusion joint involves providing a corrugated piston billet. The billet shape can be provided by a low weight piston and reinforced ring holder. The ring holder reinforced blank can also include a thin washer that is placed over the corrugated piston billet base end. After the initial forging, the washer also has a waveform. During forging of the piston crown, molten metal from the piston billet can be poured between the washers. The molten metal can fill all the spaces between the washers. A silicon having an average particle size of about 15 μm ² ,
During forging of a blank containing intermetallic particles and injection hardened particles, the resulting L / l
= A gap-free joint 1 is produced around the ring holder at intervals of 4 to 14. A blank having an average particle size of about 15 μm ² or more of silicon, intermetallic particles, and injection-hardened particles can be forged to create a void-free joint in the ring holder. The gapless joint 1 includes a spacing determined by L / l = 15-42.

A piston manufacturing method utilizing a washer as discussed above may include the step of cutting a groove in the washer to receive a compression ring. The compression ring is in physical contact with the ring groove and reduces the wear rate of the ring groove. Reinforced washers can increase the weight of the ring holder and the wear rate of the groove.

[0062] The piston manufacturing method can also include attaching a bracket formed of a refractory material to the piston case. Mounting may include any suitable means, such as, but not limited to, bolting. Since this bolting step is time consuming and expensive, the piston manufacturing method implemented according to the present invention may include attaching a bracket to the piston. The bracket can be formed as an integral flange, so that the bracket can be attached to the piston without bolts. The mechanical joints formed are the surface area of the flange,
And the orientation of the flange against the dynamic forces generated during engine operation. The joint can overcome inertia in the engine and should therefore be sufficient to hold the bracket and piston case together. Pouring molten piston material into the bracket cavity during forging in the piston manufacturing method practiced by the present invention can result in superplastic deformation conditions, including those discussed above.

The bracket may include a porous ceramic material into which an aluminum alloy can be injected to reduce weight. The ceramic material can have an open porosity of about 35% to about 50% porosity to provide frame strength. Subsequent to injecting the aluminum alloy into the ceramic material frame, the aluminum layer may be adhered to a surface capable of engaging the piston case. As a result of this bonding step, a diffusion bond is formed between the bracket and the deformed piston case. If both the injection material and the piston case have the same composition, the difference in linear expansion coefficients has been eliminated, so that the reliability of the formed joint can be enhanced. Additional deformation of the closed end piston die, e.g., a piston die subjected to compression from all sides, may be provided for a time period of about
0 ^-5 / sec can be added at a strain rate range of about 10 ^-4 / sec. This time period can result in the elimination of micropores, which results in enhanced mechanical properties in the piston.

Wear in the ring groove can be attributed to a reduction in piston alloy strength. This reduction is a result of exposure to high temperatures during the piston manufacturing process. An increase in material strength in the ring groove zone can be obtained by plasma welding. Plasma welding involves the melting of material in a ring groove zone, often by a plasma arc.
This plasma welding can be followed by the injection of alloying elements into the melt. However, these material melting steps and the resulting properties are essentially the same for hot-deformed and cast pistons. Any differences between these result when the melting step is used for the piston billet and not for the piston case.

The molten material can be characterized by large iron or nickel based intermetallic plates and shrink holes. Deformation of the molten material can occur during forging of the piston. The deformed molten material can have hardness and ultimate strength levels that often remain the same after heating to a temperature of about 250 ° C. Any enhanced features in the material can be attributed to the diffusion microstructure, as fragmentation of intermetallic particles can occur during the hot deformation process. Further enhanced features can also be attributed to the lack of stress points, such as, but not limited to, shrink holes. The absence of shrink holes can contribute to the improvement of the ultimate strength of the material, since this absence can increase the plasticity of the material.

An example of a set of piston manufacturing methods within the scope of the present invention will now be described. The following operational steps of the piston manufacturing method performed by the present invention should not be construed as limiting, but merely provide guidance to steps within the scope of the present invention. The values below are approximate unless specified otherwise.

The piston blank and the piston die can withstand primary heating. Any deformation takes place under isothermal conditions. The forging temperature is selected depending on the initial microstructure and external configuration of the piston blank. The shape of the billet can depend on the billet material composition and the average particle size of the silicon, intermetallic particles, and injection-hardened particles contained therein. Subsequent heat treatment steps for the piston manufacturing method include quenching and artificial aging.

Example 1.12% Si, 2.2% Cu, 1.1% Mg, 0.1% Ti, 1.1% N
i, cylindrical piston billet containing approximate alloy composition of 0.4% Mn, 0.8% Fe, balance Al. Billets are cut from raw material bars. This stick is 90%
Made by hot pressing the ingot at 440 ° C. or 0.86 T _melt at a strain rate of / s. The T _{melt of the} above alloy is 552 ° C. and was selected from the phase diagrams of Al-based or Mg-based systems. The microstructure of the resulting billet contains spherical silicon and intermetallic particles with an average particle size of about 5 μm ² . The billet was deformed at 520 ° C. (0.96 T _melt ) at a strain rate of 1 × 10 ⁻² / sec in a piston die system as shown in FIG. Quenching quenching, which takes place in water at 20 ° C., was performed after the deformation step. Aging was performed at 210 ° C. for 10 hours. Microstructural analysis of the material revealed no defects such as microcracks or micropores. The material has the following mechanical properties: That is, σ _b = 390 MPa
It is.

Example 2.21% Si, 1.6% Cu, 1.1% Mg, 0.1% Ti, 1.1% N
A piston billet having an alloy composition containing i, 0.5% Mn, 0.7% Fe, and the balance Al was made by block die casting. The average particle size of silicon and intermetallic particles is about 12
0 μm ^2, which is a thin layer. The billet was tamped into a conical shape with a 4 ° angle. The size of the billet was such that 50% of the surface area was in contact with the piston-die master when placed in a piston-die master having an inner diameter of 150 mm and a cone angle of 4 °. The distance from the lower base opening end of the billet to the lower base opening end of the piston / die matrix can be determined as follows. H = dK / C√F where d = 150, K = 5, C = 21, and F = 120. Distance is 3.2mm
It was calculated. The billet was deformed in a piston-die system (FIG. 1) at 480 ° C. (0.91 T _melt ) with an average strain rate of 1 × 10 ⁻⁴ / sec. The heat treatment sequence included quenching at 510 ° C and aging at 210 ° C for 10 hours. The resulting piston was determined to be essentially defect-free. Further testing showed σ _b = 250 MPa.

Example 3 At a temperature of 520 ° C. (0.96 T _melt ),
A cylindrical blank was forged in the piston die system of FIG. 1 at a strain rate of 1 × 10 ⁻² / sec. The blank was cut from a press ingot. The pressing temperature was in the range of about 440 to about 450 ° C. (0.86 T _melt to about 0.88 T _melt ) with 90% strain. The ingot composition was 12% Si, 2.2% Cu,
. It contained 1% Mg, 0.1% Ti, 0.4% Mn, 0.8% Fe and the balance Al, and contained silicon and intermetallic particles having an average particle size of about 6 μm ² . A mechanical treatment was performed on the head of the conical surface of the billet with the ring shoulder to create a cone angle of about 6 ° and a negative shoulder angle of about 3 °. A ring holder having a flat lower mouth end was formed from an aluminum alloy having a silicon content of about 18%. Ring 2
Used at 0 ° C. on the shoulder, the ring holder was compressed into a billet head.

In this series of steps described above, a closed cavity was formed between the flat base end of the ring holder and the ring shoulder of the billet. The billet with the compressed ring holder can be heated to 510 ° C. in a furnace. The billet was fitted into the piston die system while simultaneously pressing the ring holder to form a piston firebox. Under isothermal conditions at 510 ° C. (0.95T _melt )
Forging was performed using a hydraulic press at a strain rate of 10 ⁻³ / sec. After forging the ring holder, the piston was quenched in water and aged at 210 ° C. for 10 hours. According to the strength test, the joint between the piston body and the ring holder is 140MP
a.

Example 4.12% Si, 2.2% Cu, 1.1% Mg, 0.1% Ti, 1.1% N
A piston blank including an aluminum alloy having a composition containing i, 0.4% Mn, 0.8% Fe, and the balance Al was used in a piston manufacturing method. This alloy contained silicon and intermetallic particles having an average particle size of about 5 μm ² , and the particles were spherical. An alignment projection was formed on the piston and a pig iron ring holder was attached to the projection.
The pig iron ring holder was mounted by pressing the ring holder into the projection. Prior to mounting it on the billet, the ring holder was coated with a layer of an aluminum alloy melt having essentially the same composition as the billet. A billet with a ring holder was pressed into the piston-die matrix with an interference fit therebetween. Forging was performed at an average strain rate of 10 ⁻³ / sec under hot deformation conditions of 490 ° C. (0.93 T _melt ). First form the piston crown (left side of Fig. 2)
Then, the inner part was formed (right side of the figure). Subsequently, forging, quenching, and artificial aging steps were performed.

In this example, an aluminum alloy can be coated on the holder. After cooling, the aluminum alloy coating was melt bonded to the surface of the ring groove. As the ring holder was pressed into the piston billet, the oxide film coating was removed from the surfaces of both the piston billet and the ring holder. The high temperatures and deformations that occur during forging
Provided conditions that helped create permanent fusion joints. The strength of this joint is generally sufficient to prevent the formation of a gap between the piston body and the ring holder during subsequent heat treatment and use.

Example 5.12% Si, 2.2% Cu, 1.1% Mg, 0.1% Ti, 0.4% M
The aluminum alloy billet containing n, 8% Fe and the balance Al further contained silicon and intermetallic particles having an average particle size of about 12 μm ² . This billet was molded together with the integral shoulder. The end of the base opening surrounding the shoulder was corrugated as described above. Thickness 3
Ring holders were made from mm corrugated steel plates. The billet and ring-holder wave periods were calculated using the following equations. L = l (4 to 14) where l is the thickness of the plate on which the ring holder is made, for example, 3 mm. Using the above formula, L ranges from about 12 mm to about 42 mm. In the experiment, L is about 30mm
Met. The ring holder was secured to the blank and placed in the piston die matrix. Then forged the piston. Subsequent heat treatments included quenching and artificial aging.

Example 6 The composite piston included two cases, an inner case and an outer case.
The billet for the outer case is 21% Si, 1.6% Cu, 1.1% Mg, 0.1%
% Ni, 0.5% Mn, 0.7% Fe, and an aluminum alloy containing the remaining Al. It also contained silicon and intermetallic particles with an average particle size of 30 μm ² .
Billets for the inner case are 12% Si, 2.2% Cu, 1.1% Mg, 0.1%
% Of Ti, 1.1% Ni, 0.4% Mn, 0.8% Fe and the balance Al, and was formed from an alloy containing spherical silicon and intermetallic particles having an average particle size of 5 μm ² . The outer and inner case billets were washer-shaped. The piston was forged by simultaneously forging both billets at 490 ° C. (0.93 T _{me lt} ) and at a deformation rate of 10 ⁻³ / sec. The next heat treatment sequence included quenching and artificial aging.

Example 7.12% Si, 2.2% Cu, 1.1% Mg, 01. % Ti, 1.1% N
A piston billet body was made from an aluminum alloy having the following composition: i, 0.4% Mn, 0.8% Fe, balance Al. Aluminum alloy piston semi-finished products
21% Si, 1.6% Cu, 1.1% Mg, 0.1% Ti, 0.5% Mn, 0.1%
An alloy having a composition of 7% Fe and the balance of Al was included. The alloy has an average grain size of 120μ
m ² of silicon and intermetallic particles. An aluminum alloy having the same composition as the piston billet was injected into a bracket made of silica mullite having a porosity of 40%. The surface of the inner bracket was covered with an aluminum alloy layer and had a thickness of 2 mm. The bracket and billet were fitted into a piston-die matrix and heated to 480 ° C. (0.91 T _melt ). Deformation was performed at a strain rate of 10 ^-4 / sec. After forging, quenching and quenching were performed in the open air. Aging was performed at 350 ° C. for 8 hours. The connection between the piston and the bracket has proven to be reliable and permanent.

Example 8.12% Si, 2.2% Cu, 1.1% Mg, 0.1% Ti, 1.1% N
A blank was cut from a hot-pressed aluminum alloy rod having a composition of i, 0.4% Mn, 0.8% Fe, and the balance Al. The alloy contained spherical and intermetallic particles with an average particle size of 6 μm ² . At a distance of 20 mm from the end, the piston ring was melted and a nickel chrome flux such as a nickel chrome wire was injected. Melting was performed in three steps or three times using a solid electrode in an argon atmosphere. The first step was performed with a nickel chrome flux injection speed of 65 m / h and a welding speed of 41 m / h. In the second and third steps, welding was performed without injecting alloying elements, and the welding speed was 25 m / hour. The current during these steps ranged from about 680A to about 700A and the voltage was 220V. The melt depth was 7 mm.

A billet having a molten layer of 7% nickel and 2% chromium was heated to 470 ° C. (0.9 T _melt ) in a furnace. The billet was then placed in a piston die matrix mounted under a hydraulic press.

The deformation of the billet, joint, and molten layer was performed at a strain rate of 10 ⁻³ / sec. At a temperature of about 470 ° C., the blank and the piston die were forged under isothermal conditions at an average strain rate of 10 ⁻³ / sec. The piston was removed from the piston die using a pusher. Quenching was performed in water at a temperature of 510 ± 10 ° C. Aging was performed at a temperature of 210 ° C. for 10 hours. During the final mechanical treatment of the piston, a ring groove was formed. No microcracks or micropores were found.

Although various embodiments have been described herein, those skilled in the art will be able to make combinations, variations or improvements of various elements, and it is understood from the present specification that these are within the scope of the present invention. Will be understood.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a piston manufacturing system and a method on the left side of the shaft before deformation occurs and on the right side of the shaft after deformation occurs.

FIG. 2 is a schematic diagram of a piston in a ring holder manufacturing system with a billet and a ring holder in the piston die.

FIG. 3 is a schematic illustration of a piston in a ring holder manufacturing system, showing forging of the piston crown on the left side of the shaft and forging inside the piston on the right side of the shaft.

FIG. 4 is a schematic diagram of the molten piston manufacturing system, with the left side of the shaft showing before deformation and the right side of the shaft showing after deformation.

FIG. 5 is a schematic exploded view of ring holder compression molding.

FIG. 6 is a schematic view of a band-shaped piston having a ring holder.

FIG. 7 is a view showing a cup-shaped inner case.

FIG. 8 shows a cup-shaped outer piston case.

FIG. 9 is a view showing a state in which the inner case is tightly fitted into the outer case.

FIG. 10 is a view showing a composite piston after forging.

FIG. 11 is a view showing a washer-shaped outer case and a cup-shaped inner case.

FIG. 12 is a view showing washer-shaped inner and outer cases.

FIG. 13 is a schematic view of a billet fitting into a piston die implemented according to the present invention.

FIG. 14 is a photograph showing billets of various sizes manufactured by a piston manufacturing method performed according to the present invention.

FIG. 15 is a photograph of a cross section of a piston with a bracket implemented according to the present invention.

FIG. 16 is a photograph of a silumin microstructure including silicon and intermetallic particles having dimensions less than about 6 μm ² .

FIG. 17 is a photograph of a silmin microstructure including silicon and intermetallic particles excluding particles having a size of about 15 μm ² or greater.

──────────────────────────────────────────────────続 き Continued on the front page (71) Applicant Institute of Metals Super Plasticity Problems of the Lucian Academia of Sciences Russia 450001・ 39 (74) Attorney Masaki Yamakawa (72) Inventor Kaiby Chef, Oscar Akamovic, Russia 450005 ・ Ufa Bashkotstan Renena Street 31/33 ・ Apartment ・ 28 (72) Inventor Trifonov, Wadim Gennadivi ロ シ ア, Russia 450059 Ufa Bashko コ ー ト stan Nabereznaya Street 9/2 Apa Tomento · 72 F term (reference) 3J044 AA01 BA04 DA09

Claims (30)

[Claims] 1. A piston manufacturing method for manufacturing a piston of an internal combustion engine, comprising the steps of forging a billet from an initial billet including an aluminum alloy comprising silicon, intermetallic particles, and injected hardened particles, forging be performed in at least one under superplastic conditions and hot deformation conditions, including the step of heat treating the forged billet, forging is in the range of about 0.8 T _melt ~ about 0.98T _melt temperature Wherein the forging also includes forging at a strain rate ranging from about 5 × 10 ⁻² / sec to about 5 × 10 ⁻⁵ / sec, wherein the piston is capable of connecting other parts to the piston. Coarse silicon, intermetallic particles, injection hardened particles, and spherical fine silicon comprising at least one of the lamellar overall shapes. Intermetallic particles, injection hardened particles, wherein the volume content of silicon, intermetallic, injected hardened particles is in the range of about 25% to about 60%, and silicon, intermetallic, and injected hardened particles. The method of making a piston, wherein the average particle size is less than about 15 μm ² . 2. The strain rate is lower, in the range of about 10 ^{-3 to} 5 × 10 ^-5 / sec, the temperature is in the range of about 0.83 to 0.89 T _melt , and the particle content is 20. The piston manufacturing method according to claim 1, wherein the average particle size is 15 μm ² or more. 3. The silicon, wherein the initial billet has an average particle size of less than about 6 μm ² ,
The forging comprises between about 0.90 T _melt to about 0.9, including intermetallic particles and injection hardened particles.
The method of claim 1 including hot deformation forging performed at a strain rate of about 5 × 10 ^-2 / sec to about 10 ^-3 / sec in a temperature range of 8T _melt . 4. In a temperature range from about 0.79T _melt to about 0.96T _melt ,
^{4. The} method of claim 3, further comprising deforming at a strain rate range of about 5 x ^10-4 / sec to about 5 x ^10-3 / sec. 5. In a temperature range from about 0.84T _melt to about 0.96T _melt ,
At a strain rate range of about 10 ^-3 / sec to about 5 × 10 ^-4 / sec, deformation forging for billets comprising silicon average particle size in the range of about 6 [mu] m ² to about 15 [mu] m ^2, the intermetallic particles, the injection cured particles The piston manufacturing method according to claim 1, further comprising: 6. The method according to claim 1, wherein the forging is carried out under superplastic conditions at about 0.88 T _melt to about 0.9 T _melt.
Includes silicon, intermetallic particles, and injection-hardened particles having an average particle size of less than about 15 μm ² at a strain rate range of about 5 × 10 ^-5 / sec to about 1 × 10 ^-1 / sec in a temperature range of 8T _melt. The method of claim 1, wherein the volume content of silicon, intermetallic particles, and injection hardened particles ranges from about 25% to about 60%. 7. The billet containing less than about 15% silicon, intermetallic particles, and injection hardened particles includes a tapered conical shape, wherein the billet and the piston die are in contact such that the contact between the piston and the die master is at the side surface. The method of claim 1, wherein the piston is set on a die matrix and the contact occupies at least 30% of its surface. 8. The distance between the lower end of the lower opening and the base of the piston die matrix is h = 8.
dK / C√F, where d is the inner diameter (mm) of the bottom of the piston / die matrix, C is the content (% by mass) of silicon, intermetallic particles, and injection hardened particles, and F is silicon and intermetallic. The piston manufacture according to claim 7, wherein the particles, the average area of the injected hardened particles (μm ² ), and K are coefficients reflecting the shape and size of the upper die, and K ranges from about 0.5 to about 10. Method. 9. The method of claim 1, wherein the deformation is performed at a temperature equal to the quenching temperature, and the quenching quenching occurs after deformation of the billet containing silicon, intermetallic particles, and injection hardened particles having an average particle size of less than about 15 μm ^2. Piston manufacturing method. 10. The billet contains less than about 15% silicon, intermetallic particles, and injection-hardened particles having an average particle size of less than about 15 μm ^{2 and} can be provided with a ring holder, wherein the ring holder is about 20 μm ^2. A ring holder comprising an alloy containing silicon, intermetallic particles, and injection hardened particles of the above sizes in the range of about 20% to about 40% by weight, wherein the ring holder is mounted with an interference fit over the surface of the piston die. Item 1
3. The method for producing a piston according to item 1. 11. The billet comprises silicon, intermetallic particles, and injection hardened particles having an average particle size of less than about 15 μm ² , wherein the volume of silicon, intermetallic particles, and injection hardened particles ranges from about 25% to about 60%. And the ring holder has an average particle size of about 20 μm ²
The method of claim 1, comprising less than about 20% to about 45% silicon, intermetallic particles, and injection hardened particles. 12. A billet containing silicon, intermetallic particles, and injection-cured particles,
A ring holder having an average particle size of less than 5 μm ² , containing less than 15% silicon, intermetallic particles, and injection hardened particles, and comprising a ring holder made of at least one of pig iron or steel on the piston. 3. The method for producing a piston according to item 1. 13. A billet having silicon, intermetallic particles, and injection-cured particles,
It contains an average particle size of less than 15 μm ² and contains silicon, intermetallic particles,
The method of claim 1 wherein the piston is provided with a ring holder comprising pig iron or steel in the range of about 50% to about 60%. 14. A method for forming a conical ring holder having an angle of about 1 ° to about 10 ° and an alignment surface of a billet of a piston body, and a ring shoulder having a negative angle of about 1 ° to about 3 °. Wherein the ring holder is placed in the ring shoulder with an interference fit diameter ranging from about 0.1 mm to about 0.2 mm in diameter, and the arrangement of the ring holder is performed at room temperature. Item 13. The piston manufacturing method according to Item 12. 15. The method according to claim 12, wherein forging comprises two steps. 16. Placing the ring holder in a piston die matrix comprises:
Including providing an interference fit between the outer surface of the ring holder and the inner surface of the piston die master, where the interference fit is calculated as 1.0017 ≦ d / D ≦ 1.00035, where d is The outer diameter of the ring holder at the forging temperature, D is the inner diameter of the piston die master at the forging temperature. 13. The method for manufacturing a piston according to claim 12, comprising physically moving the piston. 17. The method according to claim 12, further comprising coating the ring holder with an aluminum alloy. 18. The method of claim 16, including providing a coating and a piston case formed from the same alloy. 19. The billet comprises 15% silicon, intermetallic particles, injection hardened particles, and when the billet is used to make a piston inner case with an outer body mounted in an interference fit on a side surface. 2. The method of claim 1 including using two billets to forge the piston. 20. The forging of the piston includes forging from two billets, one billet ranging from about 45% to about 60% by volume for making the piston outer case, silicon, intermetallic particles, injection hardened particles. Another billet includes 40% silicon to make the piston inner case, intermetallic particles in the range of about 25% to about 40% by volume, injection hardened particles, and the die during superforging is subjected to superplastic conditions. The method of claim 1 wherein the piston is heated to a temperature for deformation under pressure. 21. The method according to claim 19, wherein the billet has a washer shape. 22. The method for manufacturing a piston according to claim 19, wherein the billet is cup-shaped, and the outer cup is tapered toward the base end. 23. The method of claim 21, further comprising pressing the inner cup into the outer cup to form a composite billet. 24. The billet includes a corrugated ridge having a wave period L, a steel washer is disposed on the surface, the washer has a thickness satisfying the following condition: L / l = 4 to 42; The piston manufacturing method according to claim 1, wherein the relationship between the height and the shoulder is determined such that the washer is at the same level as the ring groove when forging is completed. 25. A billet comprising silicon having an average particle size of less than 15 μm ² , intermetallic particles, and injection hardened particles, which is placed in a piston die mold opposite a bracket, wherein the bracket is located at the bottom of the billet. Which results in the formation of a lock joint after the piston has been forged under hot deformation conditions, and the bracket surface area S can be determined by the following equation: S = KP / SinαF; Where P is the separating force required to overcome the dynamic forces created during engine operation, K is the reliability factor, F is the fluid resistance of the aluminum alloy at the working temperature, α is the distance between the bump and the direction of piston movement. The piston manufacturing method according to claim 1, wherein the angle is an angle. 26. The billet comprises silicon, intermetallic particles, and injection-hardened particles having an average particle size of less than 15 μm ² , and from about 25% to about 60% of the silicon, intermetallic, and injection-hardened particles. Containing the full volume, the billet is placed in a matrix opposite a bracket reflecting the billet surface, and lock joint forming is formed after the piston is forged from an aluminum alloy under superplastic conditions. , The surface area S of the bracket can be determined by the following equation: S = KP / SinαF, where P is the separating force required to overcome the dynamic force created during engine operation, K is the reliability factor, and F is The method of claim 1, wherein the fluid resistance of the aluminum alloy at the working temperature, α, is the angle between the bulge and the direction of piston movement. 27. The billet comprises silicon, intermetallic particles, and injection-hardened particles having an average particle size of less than 15 μm ² , and ranges from about 25% to about 60% of silicon, intermetallic particles, and injection-hardened particles. With a volume content, a billet is placed in a piston die matrix opposite a bracket, the bracket is made of a porous ceramic material impregnated with an aluminum alloy, and the porosity of the ceramic frame is about The method of claim 1 wherein the forging is in a range of 35% to about 50% and the forging is performed under superplastic conditions. 28. The method according to claim 26, wherein the same aluminum alloy is used for the ceramic frame and the piston case. 29. The method according to claim 29, wherein the piston is moved from about 0.5 minutes to about 5 minutes in the closed end piston die.
2. The method of claim 1 wherein the piston is further deformed at a strain rate in the range of about 10 ^<-5 > to 10 < ^-4 > / sec for a period of minutes. 30. A billet comprising silicon, intermetallic particles, and injection-hardened particles having an average particle size of less than 15 μm ² is provided, comprising forming a hardened layer on the piston surface, wherein hot deformation forging is carried out at about 0. in the temperature range of 9T _melt ~ about 0.96T _melt, the piston production method of claim 1 performed at a strain rate in the range of about 5 × 10 ^-2 ~ about 10 ^-3 / sec.