JP2002178132A - Cylinder sleeve and its method for producing the same, and cylinder block for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent seizure with a piston by strengthening joining with a cylinder body and uniformizing transfer of heat. SOLUTION: In a cylinder sleeve, a sleeve basic material is formed by using a rapidly solidified extrusion forming powder, having a chemical composition added with silicon (Si) of quantity to be a hyper-eutectic crystal composition to an aluminum alloy and projections parallely continuing in the length direction having 0.1-2 mm height, are formed on the outer surface of the sleeve basic material by adjusting the extruding conditions and also, fine cracks having depth of 10 μm- 20% of sleeve basic material thickness at the maximum, are uniformly distributed on the surface. A cylinder block for an internal combustion engine is produced by casting the sleeve 3 made of aluminum alloy in the cylinder body 2a cast in aluminum alloy and the sleeve 3 is formed by using the sleeve basic material.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a cylinder sleeve, a method for manufacturing a cylinder sleeve, and a cylinder block for an internal combustion engine.

[0002]

2. Description of the Related Art Some internal combustion engines have a cylinder block for an internal combustion engine, which is manufactured by casting a sleeve made of aluminum alloy into a cylinder body made of aluminum alloy casting and applying predetermined plating to the inner surface of the sleeve. ,
The cylinder block for an internal combustion engine is an important element for achieving a high-performance engine with light weight and good thermal conductivity.

The aluminum alloy sleeve to be cast in the cylinder block for internal combustion engines has been manufactured by, for example, subjecting a cast pipe or a continuously cast extruded pipe material to a predetermined processing.

Conventional sleeve materials include 12Si-3.
Materials such as Cu-aluminum materials were used. The cylinder body is JIS AC in case of mold casting with good castability.
JIS ADC12 for die-cast manufacturing such as 2B
Materials with good castability such as materials were used.

[0005]

When an aluminum alloy sleeve is cast into an aluminum alloy cylinder body formed by casting, the molten metal on the cylinder body side surrounds the outer periphery of the sleeve, and the sleeve is heated. While the cylinder expands thermally, the sleeve also cools and shrinks as the cylinder body is gradually cooled after casting. The molten metal on the cylinder body side shrinks due to phase transformation when solidified by cooling, and further thermally shrinks as the temperature decreases. If the linear expansion coefficient of the sleeve is high, the sleeve tightening force due to solidification shrinkage on the cylinder body side and heat shrinkage after solidification is reduced, and in a significant case, a gap is formed between the sleeve and the cylinder body.

Further, even in the operating state of the internal combustion engine, the temperature of the sleeve is lower than the temperature at the time of casting (a value close to the melting temperature of the aluminum alloy) (about 100 ° C. to 300 ° C. because air cooling and water cooling are performed). . In the internal combustion engine, when the coefficient of linear expansion of the sleeve is high, the sleeve tightening force remains relaxed, and a gap may be generated between the sleeve and the cylinder body. Heat transfer from the sleeve to the cylinder main body side is hindered by a gap between the cylinder main body and the cylinder main body, resulting in a hot spot and seizure with the piston. Further, when the deformation of the sleeve becomes large and the follow-up of the piston ring becomes insufficient, the oil consumption increases.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has an object to strengthen the connection with the cylinder body, to make the heat transfer uniform, to prevent seizure with the piston, and to reduce oil consumption. It is an object of the present invention to provide a cylinder sleeve, a method of manufacturing a cylinder sleeve, and a cylinder block for an internal combustion engine, which can perform the above-described operations.

[0008]

Means for Solving the Problems In order to solve the above problems and achieve the object, the present invention has the following constitution.

[0009] The invention described in claim 1 is based on a method of forming a sleeve base material using a rapidly solidified powder solidified extrusion forming material having a chemical composition obtained by adding an amount of silicon (Si) to a hypereutectic composition to an aluminum alloy. The protrusions are formed on the outer surface of the sleeve base material and have a height of 0.1 to 2 mm and are continuous in the length direction. The surface has a depth of 10 μm to a maximum of 20% of the thickness of the sleeve base material. Characterized by uniformly distributing the minute cracks of the above. ].

According to the first aspect of the present invention, a projection is formed on the outer surface of the sleeve base material, the projection being continuous in the length direction of 0.1 to 2 mm, and the surface has a depth of 10 μm.
-By uniformly distributing microcracks up to 20% of the thickness of the sleeve base material, the molten metal at the time of cast-in enters these microcracks, strengthening the joint with the cylinder body and uniform heat transfer. Can be

According to a second aspect of the present invention, there is provided a cylinder sleeve according to the first aspect, wherein the aluminum alloy contains 15 to 38% by weight of silicon (Si). ].

According to the second aspect of the present invention, the linear expansion coefficient of the sleeve can be reduced by adding 15 to 38% by weight of silicon (Si) to the aluminum alloy. There is no loss of plating.

According to a third aspect of the present invention, there is provided a method as described above, wherein "the primary crystal silicon (S) having an average particle size of 20 μm or less is used.
3. The cylinder sleeve according to claim 1, wherein i) is set. ].

According to the third aspect of the present invention, silicon (Si) is a primary crystal silicon (S) having an average particle diameter of 20 μm or less.
By adopting i), the coefficient of linear expansion of the sleeve can be reduced, and the thermal conductivity, workability, and plating properties are not impaired.

According to a fourth aspect of the present invention, there is provided a method as set forth in any one of the first to fourth aspects, wherein the sleeve is formed by coagulating and solidifying an aluminum alloy powder having an average particle diameter of 20 to 100 μm. Cylinder sleeve according to item. 』
It is.

According to the fourth aspect of the present invention, the sleeve is formed by agglomerating and solidifying an aluminum alloy powder having an average particle diameter of 20 to 100 μm, whereby the coefficient of linear expansion of the sleeve can be further reduced. Moreover, thermal conductivity, workability, and plating properties are not impaired.

According to a fifth aspect of the present invention, there is provided a method for forming a sleeve base material by an extrusion process using a rapidly solidified powder solidified extrusion forming material having a chemical composition obtained by adding silicon (Si) to an aluminum alloy. By adjusting the processing conditions, the outer surface of the sleeve substrate has a height of 0.1 to 2 m.
While forming a continuous projection parallel to the length direction of m,
10 μm depth on the surface up to 20% of the sleeve base material thickness
A method for manufacturing a cylinder sleeve, characterized in that minute cracks are uniformly distributed. ].

According to the fifth aspect of the present invention, the outer surface of the sleeve base material is adjusted by adjusting the extrusion processing conditions.
By forming continuous projections parallel to the length direction with a height of 0.1 to 2 mm and uniformly distributing minute cracks on the surface from a depth of 10 μm to a maximum of 20% of the sleeve base material thickness. In addition, the connection with the cylinder body can be strengthened and the heat transfer can be made uniform.

According to a sixth aspect of the present invention, there is provided a cylinder block for an internal combustion engine in which a sleeve made of aluminum alloy is cast into a cylinder body made of aluminum alloy casting.
A cylinder block for an internal combustion engine, wherein the sleeve is formed using the sleeve base material according to any one of claims 1 to 4. ].

According to the sixth aspect of the present invention, the joint with the cylinder body can be strengthened, and the heat can be uniformly transmitted to prevent the seizure with the piston.

[0021]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a cylinder sleeve, a method of manufacturing the cylinder sleeve and a cylinder block for an internal combustion engine according to the present invention.

The present invention is applied to a water-cooled or air-cooled 4-stroke internal combustion engine and a 2-stroke internal combustion engine having a cylinder block for an internal combustion engine, and the sleeve is applied to a wet or dry structure.

FIG. 1 is a sectional view of a water-cooled four-cycle internal combustion engine, and FIG. 2 is a sectional view taken along the line II-II of FIG.

FIGS. 1 and 2 show an example of this internal combustion engine.
1 shows a water-cooled four-cycle internal combustion engine having a dry-type sleeve, but the present invention is not limited to this embodiment.

An in-line four-cylinder engine is used as the four-cycle engine 1 of the vehicle. The cylinder block 2 of the four-cycle engine 1 includes a cylinder body 2a and a sleeve 3, and a piston 4 is provided on the sleeve 3 so as to be able to reciprocate. The reciprocating motion of the piston 4 rotates a crankshaft (not shown) disposed in the crank chamber 7 via the connecting rod 5. The cylinder block 2 is provided with a cylinder head 6, which is fastened and fixed to the cylinder block 2 by bolts 8. The piston 4 is provided with a piston ring 4b. A head cover 80 is provided on the cylinder head 6.

A combustion chamber 12 is formed by the sleeve 3 of the cylinder block 2, the head 4a of the piston 4, and the cylinder head 6. An ignition plug 86 is attached to the cylinder head 6 so as to face the combustion chamber 12.

The cylinder head 6 has an intake passage 13.
And an exhaust passage 14, and a collective intake pipe 15 is connected to the intake passage 13. A collective exhaust pipe 16 is connected to the exhaust passage 14.

The opening of the intake passage 13 facing the combustion chamber 12 is opened and closed by an intake valve 18, and the opening of the exhaust passage 14 facing the combustion chamber 12 is opened and closed by an exhaust valve 19. Tappets 30, 31 of the intake valve 18 and the exhaust valve 19 have camshafts 32, 33, respectively.
Cams 32a, 33a are in contact with each other, and the camshafts 32, 3
3, the cams 32a, 33a cause the tappet 30,
The intake valve 18 and the exhaust valve 19 are pushed via 31, thereby opening and closing the intake passage 13 and the exhaust passage 14.

A water jacket 20 is formed on the cylinder body 2a of the cylinder block 2.
, A water jacket 21 is formed in the cylinder head 6. The surroundings of the combustion chamber 12 are cooled by the cooling water of the water jackets 20 and 21, and the sleeve 3 has a dry structure.

FIG. 3 shows a water-cooled four-stroke internal combustion engine having a wet-type sleeve, in which cooling water around a combustion chamber 12 is cooled by cooling water in a water jacket 20, and the sleeve 3 is directly cooled by cooling water. I have. An O-ring 85 is provided under the water jacket 20 between the cylinder body 2a and the sleeve 3 for sealing.

Next, the manufacture of a cylinder block for an internal combustion engine will be described. FIG. 4 is a diagram showing a manufacturing process of a cylinder block for an internal combustion engine.

A rapidly solidified powder material is formed (Step S)
1) The rapidly solidified powder material is cold isostatically pressed to form a sleeve material (a billet) (step S2) and vacuum-sintered (step S3). Thereafter, heating and hot extrusion is performed to form a hollow hollow material, and the material is cooled (step S4). If necessary, heat treatment is performed, and the sleeve hollow material is cut and processed (step S5) to form the sleeve 3. The sleeve 3 is cast in the cylinder body 2a (step S6), annealed (step S7), plated (step S8), and subjected to honing (step S9).

As the rapidly solidified powder material in step S1, for example, an ingot of an aluminum alloy containing silicon (Si), iron (Fe) and other components with respect to a base material of aluminum (A1) is prepared. About 7
Dissolve at 00 ° C or higher, then spray in mist and cool at a cooling rate of 1
By rapidly cooling and solidifying at a temperature of 00 ° C./sec or more, it is formed as a rapidly solidified powder (powder metal) of an aluminum alloy.

As an aluminum alloy powder material for forming the sleeve material (billet), for example, silicon (S) having an average grain size of primary crystal silicon of 20 μm or less is used.
A rapidly solidified powder of an aluminum alloy containing i) in the range of 15 to 38% by weight is used.

As a rapidly solidified powder of such an aluminum alloy, aluminum (Al) is used as a base material, silicon (Si) is 15 to 38% by weight, iron (Fe) is contained in the whole.
1.5% by weight or less, copper (Cu) 6.8% by weight or less,
0.2 to 2% by weight of magnesium (Mg), 1.5% by weight or less of manganese (Mn), 0.4% by weight of chromium (Cr)
% Or less, and zinc (Zn) in a range of 0.3% by weight or less.

In the rapidly solidified powder of the aluminum alloy whose silicon content is increased to 15 to 38% by weight based on the aluminum alloy of 2000 series or 6000 specified in JIS, silicon (S
i) is added in order to increase wear resistance and seizure resistance by crystallizing hard primary crystals and eutectic silicon grains in the metal structure. Iron (Fe) disperses and strengthens the metal structure. 20
Copper (Cu) and magnesium (Mg) are added to obtain high strength at 0 ° C. or higher, and are added to increase the strength at 200 ° C. or lower. In the above range, desired wear resistance and seizure resistance and required strength at high temperature can be obtained.

In the sleeve material in which the rapidly solidified powder of the aluminum alloy is solidified as described above, the molten aluminum alloy is sprayed in the form of a mist and solidified by rapid cooling, so that the aluminum alloy powder has an average particle size. Approximately 20 to 100 μm, and silicon (Si) contained therein is hard primary crystal silicon (S) crystallized in a metal structure of an aluminum alloy which solidifies while powdering.
i) is finely divided so as to have an average particle diameter of 20 μm or less, and is dispersed for each aluminum alloy particle.

In step S2, the rapidly solidified powder material of the aluminum alloy is placed in a mold having an opening in one or a plurality of directions, and the plunger is inserted into the mold through the opening while bleeding air. While maintaining the mold and the mold in a water-tight state, a hydrostatic press is applied to apply a hydrostatic pressure to the plunger, and the rapidly solidified powder material is solidified.

In step S3, the pre-solidified rapidly solidified powder material is accommodated in a sintering mold, and the inside of the mold is evacuated and heated and pressurized to form a denser solid mass substantially free of air. Is done.

In step S4, the solid mass is accommodated in the extrusion die, heated, extruded from the die portion of the extrusion die into a hollow round bar shape, that is, a hollow element shape, cut at the cooled portion, and cut into a predetermined length of hollow. It is a round bar. In addition,
In step S4, the hardness of the extruded and cooled sleeve hollow material is set to a Rockwell hardness (HRB) of 40.
The parameters in the process are adjusted so as to be as described above.

In step S5, the sleeve is cut to the length of the sleeve material, and the inner and outer shapes and the end portions are processed to form a cast-in sleeve.

In step S6, the sleeve 3 is cast into the cylinder main body 2a by cylinder die casting in which the sleeve 3 is cast. In this case, the sleeve 3 is housed in a mold, and a part of the inner periphery of the sleeve is supported by a supporting member, and a molten metal of a predetermined aluminum alloy is poured into a gap between the mold and the outer periphery of the sleeve. This is done by guiding at high pressure. Then, machining of each part of the cylinder block 2 and the cylinder bore is performed.

By forming irregularities on the outer peripheral surface of the sleeve before casting the sleeve, even if the fastening force is reduced due to a difference in the coefficient of thermal expansion between the base material and the sleeve during operation, the sleeve can be reliably prevented from coming off. . Such irregularities on the outer peripheral surface of the sleeve can artificially form fine cracks by adjusting molding conditions such as extrusion speed and temperature when extruding the billet. Also, shot blasting can be used. In addition to shot blasting, it can be formed by other machining or pickling (etching) of the entire sleeve. Further, instead of a method of forming irregularities on the outer periphery of the sleeve by shot blasting or the like to enhance the bonding property with the base material, the sleeve and the base material may be bonded by using low melting point solder to prevent the sleeve from coming off. .

Here, the shot blast means that the particle size is 50.
１５０150 μm steel balls, carbide beads, stainless steel balls, zinc beads, glass beads, river sand containing a lot of quartz having a slightly larger particle size, etc., with a projector, for example, 40 to 80 m /
This means that a workpiece is projected at a projection speed of s.

In step S7, annealing is performed.
The hardness of the sleeve 3 after the annealing is defined as Rockwell hardness (H
RB) The heat treatment conditions are adjusted so as to be 40 or more.

The plating process in step S8 is plating of the inner surface of the sleeve. Basically, the plating process includes pretreatment including degreasing treatment, alkali etching treatment, and mixed acid etching treatment, alumite treatment as a base treatment, and composite plating treatment. It consists of two steps, and a water washing process is performed after each step.

The above plating process (step S8)
After that, the plating layer on the inner peripheral surface of the sleeve is subjected to honing by honing (step S9), and the thickness of the plating film is preferably about 50 μm, and in some cases, 20 μm to 1 μm.
00 μm and the surface roughness of the plating layer is 1.0 μm.
mRz or less. As a result, the surface of the plating layer can be surely smoothed, the coefficient of friction at the time of sliding of the piston 4 and the piston ring 4b can be reduced, and the retention of engine oil is improved and lubricity is improved. be able to. In addition, Rz is B0 of JIS standard.
601.

A conventional extruded material is used for the sleeve base material. The extruded material has a relatively low silicon content, and its thermal expansion coefficient is equal to or less than that of the aluminum casting material of the surrounding cylinder body. When manufacturing the cylinder block, when the sleeve base material is cast by the aluminum die casting, a gap is generated between the sleeve base material and the aluminum casting in a process of solidification of the casting material. The accuracy at the time of inner diameter grinding in the process may deteriorate, and the presence of the gap further deteriorates the shape such as the cylindricity and roundness of the sleeve because the thermal conductivity partially deteriorates, This causes an increase in oil consumption and a deterioration in performance.

As described above, the silicon (Si) content is reduced to 15
It is effective to use an aluminum alloy casting with a content of about 38% by weight so as not to form a gap between the sleeve base material and the aluminum casting. However, in a normal casting material, primary crystal Si grains are several tens μm or more. Therefore, even if an attempt is made to form a plating layer on the surface, the adhesion is poor, and not only may plating peel off during processing, but also sufficient durability cannot be obtained, such as plating peeling during operation.

For this reason, the sleeve 3 has an average particle size of 20 to 1
The silicon (Si) having an average particle diameter of 20 μm was formed by coagulating and solidifying an aluminum alloy powder of 00 μm.
The following primary crystal silicon (Si) is used. In the alkali etching step, which is a pretreatment for plating, the silicon (Si) particle size is sufficiently small as 20 μm or less.
-Deposition of P plating is not hindered. For this reason, the adhesion of plating can be ensured.

As described above, the aluminum alloy forming the sleeve 3 contains silicon (Si), and the silicon (Si) is converted into primary crystal silicon (Si) having an average particle diameter of 20 μm or less. (Si) on the inner peripheral surface of the sleeve by alkali etching
Is removed by alkali etching to form irregularities on the inner peripheral surface of the sleeve, and since the average particle size of the silicon (Si) particles is small, fine irregularities can be formed densely. The bonding area can be increased to further improve the bonding property, and there is an anchor effect due to the unevenness. Further, the increase in the bonding area increases the heat transfer area, and quickly dissipates the heat of the combustion gas added to the plating layer. Possible,
Hardly causes peeling of plating layer.

Further, by containing 15 to 38% by weight of silicon (Si) in the aluminum alloy constituting the sleeve 3, the silicon (Si) content is large and the average particle size of the silicon (Si) particles is small. Therefore, finer irregularities can be formed densely, and the bonding area between the inner peripheral surface of the sleeve and the plating layer increases, so that the bonding property can be further improved.

As described above, the aluminum alloy forming the sleeve 3 is made of silicon (Si) of 15 to 3 times.
8% by weight, and the coefficient of linear expansion of the sleeve 3 is 15 to 2
2 (at 200 ° C.), which is smaller than the linear expansion coefficient of the cylinder body 2a (for example, the linear expansion coefficient of the aluminum alloy ADC12 for JIS die casting is 20 (at 200 ° C.)
The coefficient of linear expansion of the sleeve 3 is at least 10% smaller than the coefficient of linear expansion of the cylinder body 2a.

Therefore, when the sleeve 3 made of aluminum alloy is cast into the cylinder body 2a of aluminum alloy casting, the molten metal on the cylinder body 2a side surrounds the outer periphery of the sleeve 3, and the sleeve 3 is heated and thermally expanded. As the cylinder body 2a is gradually cooled after filling, the sleeve 3 is also cooled and thermally contracted.
The molten metal on the side a shrinks when solidified by cooling, and further shrinks as the temperature decreases.
5 to 38% by weight, the coefficient of linear expansion of the sleeve 3 is at least 10% smaller than the coefficient of linear expansion of the cylinder body 2a, and the sleeve tightening force due to solidification shrinkage on the cylinder body 2a side and heat shrinkage after solidification is reduced. Therefore, no gap is formed between the sleeve 3 and the cylinder body 2a.

Further, a sleeve base material is formed by extrusion using a rapidly solidified powder solidified extrusion forming material having a chemical composition obtained by adding silicon (Si) to an aluminum alloy, and the extrusion processing conditions, for example, extrusion speed, temperature By forming a hollow round bar, a continuous projection parallel to the length direction of 0.1 to 2 mm in height is adjusted, or
10 μm depth on the surface up to 20% of the sleeve base material thickness
Micro cracks are uniformly distributed, and projections or micro cracks are left on the outer peripheral surface even after processing into a sleeve, so that bonding with the cylinder body 2a is strengthened and heat transfer is uniform. can do.

In the operating state, the temperature of the sleeve 3 is lower than the temperature at the time of casting (a value close to the melting temperature of the aluminum alloy) (air cooling and water cooling are performed.
About 00 ° C. to 300 ° C.) and 15 to 3 pieces of silicon (Si).
8% by weight, the coefficient of linear expansion of the sleeve 3 is at least 10% smaller than the coefficient of linear expansion of the cylinder body 2a, the sleeve tightening force is maintained, and a gap is generated between the sleeve 3 and the cylinder body 2a. The cylindrical shape and roundness of the inner circumference of the sleeve are maintained, and the heat from the circumferential surface of the sleeve 3 is transferred well to the cylinder body side via the plating layer and the inside of the sleeve 3 body, so that the hot spot is formed. And seizure with the piston 4 can be prevented.

After completion of casting (normal temperature condition), predetermined plating is performed, honing is performed to increase the cylindricity and roundness of the inner periphery of the sleeve 3, and the crankshaft and piston are mounted on the cylinder block 2. When the internal combustion engine is operated after assembling and further fastening the cylinder head 6 with bolts 8 to complete the assembly as an internal combustion engine, the sleeve 3 thermally expands, and at this time, the cylinder body 2 around the sleeve to which the cylinder head 6 is bolted is bolted. The plurality of bolt holes have increased rigidity and resist thermal expansion. On the other hand, the cylinder body 2a, which is an intermediate portion between the bolt holes on the outer periphery of the sleeve, has low resistance to thermal expansion. And a linear expansion coefficient of the sleeve 3 of the cylinder body 2
a is 10% smaller than the linear expansion coefficient of
Has a small thermal expansion, maintains the cylindricality and roundness of the inner circumference of the sleeve, improves the isolation between the combustion chamber 12 and the crank chamber 7 by the piston ring 4b, increases the oil consumption, and causes the combustion gas to flow through. Fuel economy deterioration and oil deterioration can be prevented.

Also, the combustion pressure applied through the plating layer,
Due to the tension of the piston ring, the sleeve material that supports the plating layer may yield and deteriorate, the plating layer may peel off from the sleeve material, and the cylinder head may have increased rigidity due to cylinder head tightening. If the hardness is insufficient at each part in the circumferential direction, especially when the hardness is insufficient, the rigidity is low, and there is a problem that the deformation due to thermal expansion at the middle part of the cylinder head tightening bolt hole becomes large, but there is a problem that the sleeve is constituted. 15-38% by weight of silicon (Si) and magnesium (Mg) in aluminum alloy
1.8% by weight or less, and the sleeve has a Rockwell hardness (HRB) of 40 to 70.
In addition to preventing yield deterioration, the rigidity is improved, and deformation due to thermal expansion can be reduced.

Further, at least one or more of copper (Cu), manganese (Mn) and zinc (Zn) is added to the aluminum alloy constituting the sleeve in a total of 1.7 to 1.7.
By containing 8.3% by weight, it is possible to prevent the sleeve from deteriorating in yield, improve rigidity, and reduce deformation due to thermal expansion.

Further, when the cylinder block 2 is manufactured, for example, when the sleeve base material is cast with an aluminum die casting, a gap is formed between the sleeve base material and the aluminum casting in a process of solidifying the aluminum die casting. Therefore, the accuracy during the inner diameter grinding process in the subsequent process may be deteriorated, and further, the presence of the gap deteriorates the heat conductivity partially, so that the shape of the sleeve such as cylindricity, roundness, etc. is deteriorated. Cause increase in oil consumption and deterioration of performance. However, the piston 4, the sleeve 3, and the cylinder body 2a are made of silicon (S
i) is formed of an aluminum alloy containing silicon (Si), the content of which is adjusted, and the piston 4, the sleeve 3,
The ratio of the silicon (Si) content of the cylinder body 2a is 1
When the ratio of the coefficient of linear expansion of the piston 4, the sleeve 3, and the cylinder body 2a is set to 18:16:20 at 7:25:12, when the internal combustion engine is operated, the change in the piston clearance accompanying the thermal expansion of the piston 4 is achieved. Can be kept in an ideal state, whereby loss and noise can be reduced, and oil consumption can be reduced while maintaining output performance.

As an example, JIS is used for the sleeve base material.
2 for basic chemical components of 2000 or JIS 6000 series
A manufacturing process using a rapidly solidified powder solidified extrusion forming material having a chemical composition to which 5% by weight of silicon (Si) was added was manufactured by the process of FIG.

The rapidly solidified powder of an aluminum alloy based on this JIS 2000 system and added with an amount of silicon (Si) that becomes a hypereutectic composition is based on aluminum (Al) and contains silicon (Si) throughout. 15-38% by weight,
1.5% by weight or less of iron (Fe) and 1.5% or less of copper (Cu)
6.8 wt%, magnesium (Mg) 1.8 wt% or less, manganese (Mn) 0.2-1.2 wt%, chromium (Cr) 0.1 wt% or less, zinc (Zn) 0 0.3% by weight or less and titanium (Ti) 0.2% by weight or less.

A rapidly solidified powder of an aluminum alloy based on JIS 6000 and to which an amount of silicon (Si) to give a hypereutectic composition is based on aluminum (Al), and silicon (Si) is contained in the whole. 15-38% by weight,
1.0 wt% or less of iron (Fe), 0.4 wt% or less of copper (Cu), 0.35 to 1.5 wt% of magnesium (Mg), 0.8 wt% of manganese (Mn) Hereinafter, chromium (Cr) content is 0.35% by weight or less, and zinc (Zn) 0.2
5% by weight or less and titanium (Ti) 0.15% by weight or less.

In Example 1, JIS 6000-based 6061
Using an extruded material of -25Si rapidly solidified powder solidified powder as a sleeve substrate, Ni-P-SiC dispersed composite plating was applied to the inner surface thereof.

In Example 2, JIS 6000-based 6061
+ 2-4Fe-25Si rapidly solidified powder solidified extruded material was used as a sleeve substrate, and Ni-P-SiC dispersed composite plating was applied to the inner surface thereof.

The third embodiment uses the JIS2000 system in 2017.
Alternatively, Ni-P-SiC-dispersed composite plating was applied to the inner surface of the quenched and solidified powder of 20224-25Si as a sleeve substrate.

In this embodiment, the reduction in oil consumption is an improvement in cylinder deformation, and attention has been paid to improving the close contact of the sleeve after casting. In order to improve the adhesion of the sleeve, attention was paid to changing to a sleeve material having a low coefficient of linear expansion, and a material having a low coefficient of linear expansion was selected from an iron-based material, which was lightweight and excellent in heat transfer, and was made an aluminum composite material.

The physical properties and mechanical properties of this sleeve material are compared and shown in Table 1. Table 1 shows a sleeve having a low coefficient of linear expansion aluminum as a base material and a hard film formed on the inner surface.
As shown in FIG.
3Cu aluminum alloy material, cylinder body ADC12
Reduced compared to. Cylinder body AD which is cast-in material
The ratio of C12 to the coefficient of linear expansion was 0.85, and the tightening deformation when casting the sleeve was improved.

[0069]

[Table 1] Further, the interfacial gap at the time of cast-in is reduced as shown in Table 2 by annealing at 250 ° C. × 1 hour followed by cooling. The interface gap between the sleeve and the cylinder body was measured at eight points in the circumferential direction of the sleeve. In the case of the bore No. 4, the mold cooling is stopped as an abnormality.

[0070]

[Table 2] When the interface gap at the time of cast-in decreases, as shown in Table 1,
The Young's modulus of the liner substrate is improved, the roundness and cylindricity of the cylinder after honing are improved, and the followability and sealing performance of the piston ring are improved.

Further, when the interface gap at the time of casting is reduced,
Uniformity and improvement of heat transfer have been achieved, local deformation during operation has been improved, the roundness and cylindricity of the cylinder after honing have been improved, and the followability and sealability of the piston ring have been improved. The oil consumption was improved.

In the above Examples 1 to 3, extrusion was performed using a rapidly solidified powder solidified extrusion forming material, and by adjusting the extrusion processing conditions, for example, the extrusion speed and temperature, as shown in FIG. A continuous protrusion 100 having a height of 0.1 to 2 mm parallel to the longitudinal direction is formed on the outer surface of the sleeve base material, and the surface has a depth of 10 μm to a maximum of 20% of the thickness of the sleeve base material at the maximum. The cracks 101 were uniformly distributed.

FIG. 6 is a diagram showing the relationship between the sleeve surface sharpness depth, the sleeve strength, and the interface gap.
20% of the sleeve base material thickness is 20% of the sleeve base material thickness at the maximum and the optimum range of the intense depth which can reduce the interfacial gap, and this depth is 10% to the maximum of 20% of the sleeve base material thickness at the maximum. By uniformly distributing the small cracks 101, the molten metal at the time of casting can enter the small cracks, and the joining of the casting with the cylinder body 2a can be strengthened and the heat transfer can be uniform.

In Examples 1 to 3, nickel-based dispersion plating containing phosphorus and eutectoids was performed at high speed, and nickel (Ni) -phosphorus (P) -silicon carbide (SiC) dispersion plating was performed. It is done at high speed,
This Ni-P-SiC dispersion plating has the following properties.

When the Ni-P-SiC dispersion plating is applied to the inner peripheral surface of the sleeve 3, the inner peripheral surface of the sleeve 3 is
The plating film 50 including the Ni-P matrix 51 and the eutectoid particles 52 of SiC as shown in FIG. On the surface of the plating film 50, an oil pocket 53 composed of a honing eye is formed for lubrication (FIG. 7A).
Further, when the sliding of the piston 5 due to the operation is repeated, as shown in FIG. 7B, the hard silicon carbide (S
The eutectoid particles 52 of iC) are left with the Ni-P matrix 5
As a result, the new oil pocket 54 is generated. Therefore, oil lubrication can be favorably performed over a long period of time.

The relationship between the temperature and the plating hardness was examined for Ni-P-SiC dispersed plating, Ni-SiC dispersed plating, and hard chromium plating.
The hardness of the -P-SiC dispersion plating is higher than that of the hard chromium plating, especially when heat-treated at about 350 [deg.] C., and is significantly higher than that of the Ni-SiC dispersion plating containing no phosphorus (P). This indicates that the inclusion of phosphorus increases the hardness after the heat treatment.

In this example, the adhesion of the plating was evaluated by a file test, a drilling test, a heating and quenching test, etc., on a plate-shaped test piece plated. It has been confirmed that it has improved. Further, when an endurance test of the internal combustion engine was performed, the oil consumption was reduced to about 1 /
2 was confirmed, and no trouble such as peeling of the plating occurred at all.

[0078]

As described above, according to the first aspect of the present invention, the outer surface of the sleeve substrate has a height of 0.1 to 2 m.
While forming a continuous projection parallel to the length direction of m,
10 μm depth on the surface up to 20% of the sleeve base material thickness
By uniformly distributing the minute cracks, the molten metal at the time of cast-in enters into the minute cracks, whereby the joining with the cylinder body can be strengthened and the heat transfer can be uniform.

According to the second aspect of the present invention, the linear expansion coefficient of the sleeve can be reduced by adding 15 to 38% by weight of silicon (Si) to the aluminum alloy, and the thermal conductivity, workability, and plating property can be reduced. Does not impair.

According to the third aspect of the present invention, silicon (S
i) is a primary crystal silicon (Si) having an average particle size of 20 μm or less.
By doing so, the coefficient of linear expansion of the sleeve can be further reduced, and the thermal conductivity, workability and plating properties are not impaired.

According to the fourth aspect of the present invention, the sleeve is formed by agglomerating and solidifying aluminum alloy powder having an average particle diameter of 20 to 100 μm, so that the coefficient of linear expansion of the sleeve can be further reduced, and the thermal expansion coefficient can be reduced. Does not impair conductivity, workability, and plating properties.

According to the fifth aspect of the present invention, a continuous projection parallel to the length direction of 0.1 to 2 mm is formed on the outer surface of the sleeve base by adjusting the extrusion processing conditions. By uniformly distributing microcracks having a depth of 10 μm to a maximum of 20% of the thickness of the sleeve base material on the surface, bonding to the cylinder body can be strengthened and heat transfer can be uniform.

According to the sixth aspect of the present invention, the connection with the cylinder body can be strengthened, and the heat can be uniformly transmitted to prevent seizure with the piston.

[Brief description of the drawings]

FIG. 1 is a sectional view of a water-cooled four-stroke internal combustion engine having a dry-type sleeve.

FIG. 2 is a sectional view taken along the line II-II in FIG.

FIG. 3 is a sectional view of a water-cooled four-stroke internal combustion engine having a wet-type sleeve.

FIG. 4 is a view showing a manufacturing process of a cylinder block for an internal combustion engine.

FIG. 5 is a diagram showing a state of an outer surface of a sleeve base material.

FIG. 6 is a diagram showing the relationship between the sleeve surface sharpness depth, the sleeve strength, and the interface gap.

FIG. 7 is a diagram showing Ni—P—SiC dispersed composite plating.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Water-cooled 4-cycle internal combustion engine 2 Cylinder block for internal combustion engines 2a Cylinder main body 3 Sleeve 4 Piston

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B22F 7/08 B22F 7/08 D C22C 21/02 C22C 21/02 F02F 1/00 F02F 1/00 CG F (72) Inventor Kenji Araki 2500 Shinkai, Iwata-shi, Shizuoka Yamaha Motor Co., Ltd. (72) Inventor Daisuke Nakao 2500 Shinkai, Iwata-shi, Shizuoka Yamaha Motor F-term (reference) 3G024 AA25 AA26 AA27 AA30 BA05 BA06 BA09 CA02 DA01 DA03 DA08 DA18 DA22 EA01 FA06 FA07 FA08 GA03 GA16 GA31 HA07 4K018 AA16 BA08 BD10 EA33 JA34 KA02 KA08

Claims (6)

[Claims] A sleeve base material is formed by using a rapidly solidified powder solidified extrusion forming material having a chemical composition obtained by adding an amount of silicon (Si) to a hypereutectic composition to an aluminum alloy. On the outer surface, protrusions that are continuous in the length direction are continuously formed in the length direction of 0.1 to 2 mm, and minute cracks having a depth of 10 μm to a maximum of 20% of the thickness of the sleeve base material are uniformly distributed on the surface. A cylinder sleeve characterized in that: 2. The method according to claim 1, wherein said aluminum alloy is silicon (Si).
The cylinder sleeve according to claim 1, wherein 15 to 38% by weight is contained. 3. The silicon (Si) has an average particle size of 20 μm.
The cylinder sleeve according to claim 1 or 2, wherein the primary crystal silicon (Si) is not more than m. 4. The sleeve having an average particle size of 20 to 100 μm.
The cylinder sleeve according to any one of claims 1 to 4, wherein m aluminum alloy powder is formed by coagulation and solidification. 5. A sleeve base material is formed by extrusion using a rapidly solidified powder solidified extrusion forming material having a chemical composition obtained by adding silicon (Si) to an aluminum alloy, and by adjusting the extrusion processing conditions, the sleeve is formed. On the outer surface of the base material, continuous projections are formed in parallel with the length direction of the base material at a height of 0.1 to 2 mm, and minute cracks having a depth of 10 μm to a maximum of 20% of the thickness of the sleeve base material are formed on the surface. A method for manufacturing a cylinder sleeve, wherein the cylinder sleeves are distributed in the following manner. 6. A cylinder block for an internal combustion engine in which a sleeve made of an aluminum alloy is cast into a cylinder body made of an aluminum alloy casting, wherein the sleeve is according to any one of claims 1 to 4. A cylinder block for an internal combustion engine, formed using a sleeve base material.