JPS6018261A - Manufacture of two-layered cylinder liner - Google Patents

Abstract

PURPOSE:To obtain a cylinder liner which is thin walled, is light and has excellent slidability by forming the inside layer of a cast iron and the outside layer of a cast steel by a vertical type centrifugal casting method. CONSTITUTION:A core 2 provided with a hole in common use as a pouring port 3 at the center and an aperture in the lower part is disposed concentrically at the center of a metallic mold 1 and the top end 6 of the core 2 is fixed to the mold 1. The mold 1 is then rotated and the melt 13 of a cast steel is poured through the port 3. The melt 13 enters a cavity part 11 where the melt is risen along the inside surface of the mold 1 by centrifugal force. The molten cast iron to be formed as an inside layer 15' is then cast in the same way as mentioned above upon lapse of a specified time and immediately the rotation of the die 1 is stopped to allow the molten metal to solidify. The two-layered cylinder united with the outside layer 14' and the inside layer 15' to one body is removed from the mold 1. The cylinder liner which is thin walled, is light and has good slidability is obtd.

Description

[Detailed description of the invention] The present invention relates to a method for manufacturing a double-layer cylinder litchi.

Conventionally, there are two methods for manufacturing diesel i cylinder liners: a sand casting method and a centrifugal casting method.

A summary of these is shown below.

(1) Sand mold pouring method This method casts cast iron by molding the outer mold and core in a sand mold such as a Fran mold or CO2 mold, but the core is cooled extensively to precipitate carbides on the surface. Win money.

(2) Centrifugal casting method This is a manufacturing method in which cast iron is cast onto the inner surface of the mold while rotating the mold at high speed.

The disadvantages of the sand mold pouring method and the centrifugal casting method are as follows.

(1) Sand mold pouring method A large number of cold metals are applied to the surface, and the sand is pounded and hardened on the back side to produce a core, which is combined with the outer mold of a separately manufactured sand mold to cast cast iron. This method requires a large amount of molding, and the cylinder litchi is expensive.

(2) Centrifugal casting method Cast iron solidifies from the outside of the mold, and solidifies last near the inside. However, component segregation and shrinkage cavities occur in the part #/C that hardens last, so these need to be removed, and the 70 scale of the wall thickness becomes the cutting allowance. For this reason, the casting yield is low, and it is difficult to control the wear resistance, which is the most important property of a cylinder liner, and the microscopic structure that dominates the entire cylinder liner.

Tallinta liners manufactured by the sand mold pouring method and centrifugal casting method are made of cast iron integrally for better wear resistance, but the lower strength of cast iron is Katafunegawa Diesel engine cylinder lychee, its wall thickness is 70I+! ! If the TI or higher is reached, it is necessary to increase the amount and downsize the R.

The present invention uses a high-strength steel thread material in the outer layer and cast iron in the inner layer, and minimizes the mechanical cutting of the inner surface.
The present invention provides a method for manufacturing this double-layer cylinder litchi.

That is, the present invention tJ% vertical centrifugal casting method [. i', - In the center of the mold, place a core with a hole that also serves as a pouring hole in the center and an opening in a part of the hole, which should become the outer layer without being separated. The cast steel is poured into the mold from the pouring port of the core by opening the opening, and after a certain period of time, the cast iron that will become the inner layer is poured in the same way as the cast steel, and then the mold is rotated 7-1-50 minutes. 1qLl-1. The present invention relates to a method for manufacturing a two-layer cylinder liner, which comprises solidifying and melting the cast steel and cast iron.

The new ideas of the present invention are as follows.

(1) The inner layer that requires sliding properties is made of cast iron, and the outer layer that holds it is made of a high-strength steel material. (2) The outer layer and the inner layer are cast by a vertical centrifugal casting method, and moreover, from the center of a core placed in the middle of the mold.

(3) Immediately after the inner layer is π-molded, the rotation of the mold is stopped, and the inner surface of the inner layer is brought into contact with the core K and solidified.

The method of the present invention includes a reciprocating internal combustion engine Q1;
It can be applied to the cylinder litchi of reciprocating compression engines, the Talintara liner of reciprocating hydraulic hydraulics, etc.

A specific embodiment of the method of the present invention will be explained based on FIGS. 1, 2, 6, and 4.

Figure 1 is gold for centrifugal casting! (Fig. 2 shows the situation where the core is installed in the inner layer and 1c is cast. Figure 5 shows the situation where the inner layer is cast and the mold rotation is stopped to cool it down.) , 4th Mi; I produced a 7-vinyl double-layer cylinder lychee according to the method, respectively. In Figures 1 to 4, 1}. It is made of cast steel (SC42).Although it can also be made of low-base metal steel or stainless steel, carbon steel is generally used because it is inexpensive.

2 is a core placed concentrically in the center of the mold 1, with a hole 6 in the center of the warp serving as a pouring hole, and a hole 2 in the middle.
At the bottom of the opening 1-1 part 4 are spaced at equal intervals in the circumferential direction.
There are places. This core 2 is filled with a mold of 1 liter and is hardened using sand 5.

The core 2 and U/filler sand 5 are manufactured by hardening molding sand with furan resin.

The upper end of the core 2 (1, 2) is supported by the mold 6, the upper mold 6 is similar to the mold 1 (ζ) and is generally made of carbon F'nJljfM products (Sc42>tc. 1: tte l
'psa 17, mold 1vrc bolt 7 li'd fixed no 16.

Mold 1 rotates! 71] 10 and the connected base 8 is disturbed by the protrusion 9.

11 (・Mold 1 and core 2 make 12 [1 piece/ζ
It is hollow.

12 is a ladle for casting molten metal 13.

14 The ladle 12 is used to cast high-strength steel materials, such as carbon steel cast steel (SC), welded structural cast steel (SC).
V7), Structural high-strength carbon steel cast iron (SCC) low alloy cast steel (SC.lvin, SCSIMn, SCMnCr, SC
．． MnM, SC'CrM, SCM: +CrM, SCNC
rM), SdenoresfiMfl'Jm (scs), heat-resistant steel casting <4 (+CH), high manganese steel casting @l (SCMn
H) uJStlQ (SCPH) for high temperature and high pressure, for low temperature and high pressure; molten metal of apricot steel (SCPL), bite/ζ15 is ladle 1
Cast iron cast by 2, such as Panesumi Casting Spheroidal Graphite Cast Iron, Beinai? The molten metal 1 (', zo iL) of acicular cast iron is solidified to form the outer layer 1 of the cylinder lychee.
4' and the O-inner layer 15' A manufacturing method of the cylinder lychee based on the method of the present invention will be described one by one below.

First, in FIG. 1: (1) The core 2 is placed concentrically in the center of the mold 1. At this time, the bottom VC at the center of the core is filled with sand 5.

(2) Pass the upper end of the middle 12 through the hole drilled in its center, and fix the clay mold 6 with the mold 1e.

Then, in FIG. 2: (3) The rotating shaft 10. While rotating the mold 1 through the base plate 8, a molten metal 13 of, for example, cast carbon steel (SC42), which will become the outer layer, is formed in the center of the core 2 with the ladle 12, and l'l. (4) The molten metal 15 cast from the pouring spout 3 enters the cavity 11 from the opening 4 and is sealed along the inner surface of the mold 1 by centrifugal force. After that, in Fig. 3: (5) After casting the outer layer, for example, after 3 minutes, 1? After L, for example, molten gray cast iron 15, which will become the inner layer, is cast at 1,400°C. The chemical composition of the gray cast iron used in the present invention is T. C: 3.09%, Si: 1.02%, Mn
:o. ss%, p:o. 36%, V: 0.1656, T
i: 0.0691r, remaining 2 Fe.

(After casting the molten gray cast iron 15 that will become the sixth inner layer 15', the rotation of the mold 1 is stopped and the gray cast iron 15 is solidified.

Finally, in FIG. 4: (7) After solidification, the outer layer 14' and the inner layer 15' become -1. ．． The old two-layer cylinder was removed from the mold 1, and the gray cast iron 17 {r- that had solidified inside the core 2, runner 3, and opening 4 in Figure 3 was removed, and the two-layer cylinder litchi was removed. To manufacture.

According to the method of the present invention detailed above, the following effects can be achieved.

(1) Two JVs with high-strength steel for the outer layer and K cast iron for the inner layer
I borrowed 7. The overall thickness can be made thinner, and the cylinder liner becomes lighter and slower.

(2) After casting the four irons that will become the inner layer, is the mold rotated in 1ζ? Since the cast iron is stopped and allowed to solidify, the inner surface of the cast iron comes into contact with the core and solidifies. Therefore, the inner surface of the inner layer can be prevented from shrinkage and segregation, which are common defects caused by centrifugal casting.

(3) Since no defect occurs on the inner surface of the inner layer due to the centrifugal casting method, a metal composite fiber with excellent sliding properties, which is commonly used as Schilling Litchi, can be grown.

4. f in the drawing? ? A simple explanation and Figures 1 to 4 illustrate the method of the present invention! It is the 7th figure which will be explained later.

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Claims (1)

[Claims] In the vertical centrifugal casting method, a core with a hole in the center that also serves as a spout and an opening at the bottom is placed in the center of the mold, and the cast steel that will become the outer layer is first poured into the mold. Pour the metal into the mold through the opening in the core, and after a certain period of time,
A method for producing a two-layer cylinder lychee, which includes the steps of: inserting the inner layer of cast iron in the same way as the cast steel, and then immediately stopping the rotation of the mold to solidify the cast steel and cast iron.