JPS61124772A - Cylinder sleeve for reciprocation machine - Google Patents

Abstract

PURPOSE:To stabilize the structure of the slidable surface of a piston by finishing the semimanufactured article obtained through friction welding for a cylinder part obtained from centrifugal casting and a collar part projecting in the direction of outer circumference from the upper edge of the cylinder part, through machining. CONSTITUTION:A cylinder part 44 having a piston hole and a collar part 45 fixed at one edge of the cylinder part 44 are prepared separately, and a cylinder sleeve 42 is formed by integrally joining in metallurigical form the cylinder part 44 onto the edge surface of the collar part 45 through friction welding. Said cylinder part 44 is formed through the centrifugal casting of the casted iron containing 3-10% phosphorus to improve abrasion resistance and seizure- proofness, and the three-component eutectic mixture composition consisting of phosphorus, iron, and carbon is distributed uniformly inside. After the joint, the material forming the collar part 45 is cut by a cutting tool C at the position departed by a proper distance (t) from the joint part 46, and the necessary finishing works are carried-out for finishing.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a cylinder sleeve used in internal combustion engines, air pumps, and other reciprocating machines operated by the reciprocating motion of a piston.

[Conventional technology]

The cylinder sleeve is generally a cylinder body made of fusion metal.
It consists of a thin cylindrical part into which the piston is inserted and has a piston hole, and a flange part with a slightly larger diameter provided at one end of the cylindrical part. The flange part is for securely supporting the cylinder sleeve between the cylinder and the cylinder head, and has a wall thickness t approximately twice that of the cylindrical part.
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On the other hand, the material used for the cylinder sleeve is high phosphorus cast iron, which has excellent lubricity and anti-seizure properties.Furthermore, its wall thickness is extremely thin compared to its diameter, so it is difficult to produce the cylinder sleeve by centrifugal casting. Most efficient.

However, since a uniform tube with as little diameter variation as possible is suitable for casting using the centrifugal casting method, the material for the cylinder sleeve is cast to have a thick wall with machining allowance added to the flange. Therefore, a large amount of the outer periphery of the cylindrical part had to be removed,
Not only is the material yield poor, but the hard parts near the outer surface of the material tube are removed and the strength is reduced, so if the material is thickened to obtain strength, the heat dissipation performance will be reduced.

Conventionally, in order to obtain a highly rigid and thin cylinder sleeve free from such defects, it has been known to weld an annular flange to the outer periphery of the end of a cylindrical N1 material (
For example, Japanese Utility Model Publication No. 54-29364).

[Problem that the invention seeks to solve]

However, in such a structure, the welding length becomes long, making it difficult to improve productivity, and the melting range is wide, resulting in uneven material structure, which impairs quality stability. There was a drawback.

[Means for solving problems]

The purpose of this invention is to obtain a cylinder sleeve free from the above-mentioned problems, and the purpose of this invention is to combine a cylindrical part having a guide hole for a piston and a flange protruding from the upper end of the cylindrical part in the outer circumferential direction with a cylindrical flange material. The material is formed by friction welding the end face and the cylindrical material cast by the centrifugal casting method.

〔Example〕

Hereinafter, the present invention will be explained with reference to the illustrated embodiment. In the figure, 1 is a four-stroke engine, and the engine 1 has a cylinder 4 in the upper part of a crankcase 3 that supports a crankshaft 2, and a connecting rod is provided therein. A piston 6 connected to the crankshaft 2 via a piston 5 is slidably fitted therein. A cylinder head 7 is attached to the upper part of the cylinder 4, and a combustion chamber 8, which is a compression chamber, is formed at the top of the piston 6. 9 is an intake valve, and 10 is an exhaust valve. The above configuration is not particularly different from conventional engines.

Here, the cylinder 4 consists of a light alloy cylinder body 41 and a cylinder sleeve 42 having a guide hole for the piston 6, and the cylinder sleeve 42 further includes a cylindrical portion 44 having a piston hole, and a collar fixed to one end of the cylinder body 41. 45 are prepared separately, and the cylindrical portion 44 is friction welded to the end face of the flange portion 45 to metallurgically join them together. The cylindrical portion 44 has a thickness of 3 to 10% to increase wear resistance or seizure resistance.
This product is centrifugally cast from high-phosphorus cast iron containing phosphorus, and has a ternary eutectic composition (steadite) consisting of phosphorus, iron, and carbon uniformly distributed inside, which improves wear resistance and seizure resistance. I'm trying. The material for the cylindrical portion 44 is made by centrifugally casting a cast iron material several times as long as the length of the cylinder sleeve, and cutting it by lathe f to obtain a cylindrical portion material of unit length, as shown in Fig. 3(a).
As shown, friction welding is performed by rotating a relatively long cylindrical ordinary cast iron material A forming the flange 45 at high speed, and pushing the cylindrical material B with its axis aligned with the material A. After joining, as shown in FIG. 4(b), the material forming the flange 45 is cut with a cutting tool C at a position separated by an appropriate distance t from the joining part 46, and then the required finishing process is performed. Finalize.

Generally, a cylindrical mold is used for centrifugal casting of the cylindrical material, and a cylindrical cylinder sleeve is cast by pouring molten metal into the mold while it is rotating. Therefore, the area near the outer periphery of the resulting cylindrical material is a chilled casting, so it is extremely hard, and gradually softens toward the inside, and care is taken to ensure that a large amount of pearlite, free carbon, and graphite are deposited on the sliding surface of the piston. Become.

〔Effect of the invention〕

As described above, the cylinder sleeve according to the present invention is obtained by machining a product obtained by friction welding a cylindrical part cast by centrifugal casting and a flange projecting in the outer circumferential direction from the upper end of the cylindrical part. Because it is finished, the inner surface on which the piston slides has a stable structure with steadite evenly distributed in a pearlite-based structure, providing the same wear resistance and seizure resistance as conventional pistons. In addition, since the outer surface of the cylindrical part of the cylinder sleeve is rapidly cooled by a centrifugal casting mold, a large amount of cementite is precipitated and high strength is obtained. Because the remaining part supports the soft sliding surface of the piston from behind, it will not be crushed when it is press-fitted into the cylinder body or when it is cast into the cylinder body, resulting in a thin-walled cylinder sleeve. Heat dissipates to the body. Furthermore, since the hardness distribution is concentrically distributed in the cylindrical cylinder sleeve, there is no non-uniform residual stress and there is no loss of accuracy of the cylinder.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention; FIG. 1 is a sectional view showing a part of the engine, FIG. 2 is an enlarged view of the main part,
FIG. 3 is a sectional view for explaining the manufacturing method. 42...Cylinder sleeve, 44.Fist--cylindrical part,
45...+1 Tsuba. Tokiuchi applicant Yama 71 Hatsuki Co., Ltd. Agent Kazukai Yamakawa (4 or 2 people) Figure 1 Figure 3 (b) (C) Procedural amendment (Saba) 1. Indication of the case 1988 Special Patent Application No. 243153 2, Title of Invention Cylinder Sleeve for Reciprocating Machine 3, Relationship with Amendment Case Patent Name of Applicant (Name)
(AO7) Yamaha Motor Co., Ltd. 5, Subject of amendment (1) The scope of claims in the specification will be amended as shown in the attached sheet. (2) "3-10es" in the first line of page 5 is corrected to "0.3-1. (IJ), which is well known as a material for cylinder sleeves." (1) Having a piston guide hole A reciprocating machine in which a cylindrical part and a flange protruding from its upper end in the outer circumferential direction are made of a cylindrical flange material and a cylindrical part material cast by a centrifugal casting method that is friction welded to the end surface of the cylindrical part. Cylinder sleeve. (2) The cylinder sleeve for a reciprocating machine according to claim 1, wherein the cylindrical portion is configured such that its hardness decreases concentrically from the outer circumference toward the inner circumference. A cylinder sleeve for a reciprocating machine according to claim 1, wherein the cylinder sleeve is friction welded to one end surface of the cylinder sleeve.

Claims (4)

[Claims] (1) A cylindrical part that is cast by a centrifugal casting method in which a cylindrical part having a piston guide hole and a flange protruding from its upper end in the outer circumferential direction are friction welded to the cylindrical flange material and its end surface. Cylinder sleeve for reciprocating machinery made of material. (2) The cylindrical part is made of high phosphorous cast iron containing 3 to 10% phosphorus, and the flange part is made of an iron material that does not contain phosphorus or contains a trace amount of phosphorus as an impurity. Cylinder sleeve for the reciprocating machine described. (3) A cylinder sleeve for a reciprocating machine according to claim 1, wherein the cylindrical portion is configured such that its hardness decreases concentrically from the outer circumference toward the inner circumference. (4) A cylinder sleeve for a reciprocating machine according to claim 1, wherein the cylindrical portion is friction welded to one end surface of the collar portion.