JPH0366058B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to a method of manufacturing a journal bearing integrally cast from different materials.

``Prior Art'' Traditionally, journal bearings are made by separately casting bearing materials such as white metal and cast iron bearing boxes.
After each bearing was machined to the required dimensions, the bearing material was press-fitted into the hole in the bearing box and fixed with an interference fit.

"Problems to be Solved by the Invention" In the conventional journal bearings described above, the bearing material is press-fitted into the bearing box for a tight fit, so the hole diameter of the bearing box and the outer and inner diameters of the bearing material are precisely machined. I had to. In addition, when press-fitting a slightly soft bearing material into a cast iron bearing box, you must be very careful to match the centers of each piece, and the bearing material is easily damaged, so if it is damaged, it may be necessary to replace it with the required tightening fit. This resulted in drawbacks such as the bearing material rotating relative to the bearing box during use of the journal bearing. SUMMARY OF THE INVENTION An object of the present invention is to provide a method for manufacturing a journal bearing made of dissimilar materials that ensures tight fit when the bearing material is integrally cast into a bearing box and prevents accidents during use.

"Means and effects for solving the problem" The manufacturing method of the present invention includes a hole in which a core with a required diameter is erected in the center of a lower mother mold, a cavity corresponding to the bearing material, and an outer diameter of the bearing material. A hole that is suitable for mounting a chiller with a length equal to the length of the bearing material and a required thickness, and a recessed hole with a space equivalent to half of the bearing box in the axial direction are provided in the upper mother mold. Similar to the lower mother mold, there are holes into which the upper half of the core and cooling metal are inserted, and empty spaces and recessed holes corresponding to the upper half of the bearing material and the bearing box. The metal is erected, a mother mold is placed over it, and molten cast iron for the bearing box material is poured in. After this molten metal begins to solidify and cools down to a temperature lower than the melting point of the bearing material, the molten metal for the bearing material is poured.

The melting point of cast iron is approximately 1300℃, and before the entire cast iron is cooled down to the melting point of the bearing material, which is approximately 800℃, the chiller cools the molten metal of the bearing material quickly. By speeding up the injection timing to shorten waiting time and improve manufacturing efficiency, as well as promoting the solidification and cooling of the bearing material and cooling earlier than the parts of the bearing box material far from the bearing material, the journal bearing can be completed. This ensures a tight fit between the two, and since molten metal is injected onto both sides of the cold metal, the fusion effect is also great. This is convenient because the temperature of the chiller can be measured when adjusting the cooling temperature. It has the following characteristics.

"Example" In Fig. 1, a completed journal bearing 1 is shown, and a cylindrical cold metal 3 is placed in a bearing box 2 made of cast iron.
A cylindrical bearing material 4 made of a plain bearing material such as white metal is integrally cast.

FIG. 2 shows the structure of a mold used in the manufacturing method of the present invention. A center hole 7 penetrating vertically is provided in the center of the lower mother mold 5, and a core 6 is inserted into it to stand it up. A cylindrical cold metal 3 having the same length as the completed bearing material 4, an inner diameter equal to the outer diameter of the bearing material 4, and a required thickness is inserted into the outer periphery of the core 6 concentrically with the core 6. Make a hole 8 and set up a cold metal 3. A recessed hole 9 corresponding to the axial half of the bearing box 2 is provided on the outer circumference of the chiller 3, and a runner 10 for injecting molten metal for the bearing box material is provided in communication with the recessed hole 9. .

At the center of the upper matrix 11 is a sprue 13 that passes through the upper part of the core 6 and communicates with a cavity 12 corresponding to the bearing material 4 formed between the inner periphery of the chiller 3 and the outer periphery of the core 6. It is set up. A hole 8' into which the upper part of the chiller 3 is inserted is provided on the outer periphery of the cavity 12. A recessed hole 9' corresponding to the other half of the bearing box 2 in the axial direction is provided on the outer periphery of the hole 8'. The upper matrix mold 11 is provided with a sprue 14 that communicates with the runner 10 of the lower matrix mold 5.

After inserting the core 6 into the center hole 7 of the lower mother mold 5 and the cooling metal 3 into the vertical hole 8, the upper mother mold 11 is placed on the upper mother mold 11, and the upper part of the core 6 protrudes into the center of the sprue 13. Fit the upper part of the metal 3 into the hole 8'. Approximately 1300℃
Inject the molten metal of the bearing box material from the sprue 14,
0, filling the recesses 9 and 9' and filling up to the sprue 14 to form a riser. The molten metal of the bearing box material solidifies and cools quickly in the portion that comes into contact with the cooling metal 3. Cold gold 3
When the temperature of the bearing material 4 reaches a required temperature lower than the melting point of about 800°C, the molten metal of the bearing material is injected from the sprue 13 to fill the cavity 12 and fill the sprue 13 to form a riser. The temperature of the chiller 3 when injecting the molten metal of the bearing material depends on the thickness of the chiller 3, the thickness of the bearing material 4, and the strength of the interference fit of the bearing material 4 into the bearing box 2 of the completed journal bearing 1. The optimum temperature is determined based on the temperature. After cooling, the excess bearing box material and bearing material are cut off, and the inner diameter of the bearing material 4 is precisely finished to complete the journal bearing 1.

"Effects of the Invention" As is clear from the above description, according to the present invention, by casting the bearing material at an appropriate temperature while cooling the bearing box material using a cold metal, different materials can be made to have the required strength. Since it is an interference fit and molten metal is injected on both sides of the chilled metal, some fusion occurs and it is possible to cast it in one piece. Therefore, in the completed journal bearing, the bearing material is securely fixed, there is no risk of the bearing material rotating during use, and unlike conventional bearings, the fitting part between the bearing box and the bearing material is precisely finished, and This eliminates the hassle of press-fitting. The practical effects and benefits are great.

[Brief explanation of drawings]

FIG. 1 shows a journal bearing according to the invention,
Figure a is a longitudinal sectional view, Figure b is a side view, and Figure 2 is a longitudinal sectional view of a mold for carrying out the present invention. 1 is a journal bearing, 2 is a bearing box, 3 is a cold metal, 4 is a bearing material, 5 is a lower mother mold, 6 is a core, 7 is a center hole, 8 is a hole, 9 is a recessed hole, 10 is a runner , 11 is an upper matrix, 12 is a vacant chamber, 13 is a sprue, and 14 is a sprue.

Claims (1)

[Claims] 1. In the method of manufacturing journal bearings by casting, a core having an outer diameter corresponding to the inner diameter of the bearing material is placed in the center of the mold, and a void corresponding to the length and thickness of the bearing material is formed around the outer periphery of the core. A cylindrical chiller having the same length and required thickness as the bearing material is provided on the outer periphery of the empty chamber, a recessed hole corresponding to a bearing box is provided on the outer periphery of the chiller, and The molten metal of the bearing material is injected into the vacant space at a time when the temperature of the cooling metal reaches a required temperature lower than the melting point of the bearing material during cooling of the bearing box material injected as molten metal into the hole. A method for manufacturing a journal bearing that is integrally cast with different materials.