JPS6021381Y2 - Heat treatment tray - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a heat treatment tray, and more specifically, it is an integral casting made by connecting cylindrical ribs having several cylindrical holes inside a peripheral frame with connecting ribs. Regarding manufactured trays.

Conventionally, heat treatment furnaces such as quenching, tempering, or normalizing;
Various types of trays are used in continuous heat treatment furnaces, etc. For example, the tray shaped as shown in Fig. 1 is manufactured as an integral casting made of heat-resistant cast steel or other iron alloys depending on the application. The cylindrical holes are used as a holding net to prevent the heat-treated material from falling out during heat treatment of shafts, or as support holes for the vertical rods of the holding frame, and the cylindrical ribs with these several cylindrical holes are used as the surrounding frame. By arranging it inside, it is intended to alleviate thermal strain during heating and cooling.

The shape of such a cylindrical hole is usually a simple cylindrical hole as shown in Fig. 3, or a hollow part provided in the middle of the inner surface of the cylindrical hole as shown in Fig. 4. In the former case, drilling a cylindrical hole by machining will result in high machining costs, and if the hole is cast as it is, the precision will be poor and the installation may become unstable when supporting the vertical rod.

On the other hand, in the latter case, the length of the cylindrical hole is not made larger than necessary, and the cost required for machining the hole is reduced.
Even if the hole is a cast hole, accuracy is maintained by reducing the influence of dimensional errors in the hole.

In addition, it is desirable to increase the outer diameter of the cylindrical rib without increasing the weight too much in order to alleviate thermal distortion. A stepped part, that is, part F shown in Fig. 4, is formed, and cavities are likely to occur near this part due to gas during casting and sink marks during solidification, and furthermore, a ring-shaped central cavity occurs near part E. It has been difficult to eliminate these casting defects.

During quenching, salt bath treatment, etc. that use water, salt water, oil, etc. as the cooling liquid, the spaces created by the holding net or the vertical rods of the holding frame and the hollow parts, as well as the holes in defective areas, become reservoirs for the cooling liquid. The heat treatment in the next step evaporates or burns, disturbing the atmosphere in the furnace, and repeated use causes cracks and destruction at casting defects, which significantly shortens the durability of the tray.

The present invention aims to eliminate the above-mentioned inconveniences and provide a tray that can withstand use for a long period of time. Set the thickness above the hollow part,
The heat treatment tray is formed to gradually decrease from both lower ends toward the center, and no ring-shaped stepped portion is formed in the shape of the boundary between the upper and lower cylindrical holes and the middle hollow part. At the same time, the wall thickness of the cylindrical rib with the hollow part should be adjusted during mold making and casting work.
It is also designed to be most convenient for use.

Hereinafter, the structure of the present invention will be explained based on an embodiment shown in the drawings.

In Fig. 1, 1 is a peripheral frame, 2 is several cylindrical ribs provided inside the peripheral frame 1, 3 is a connecting rib, and 4 is a cavity surrounded by the connecting ribs, etc., and the cavity 4 is subjected to heat treatment. (not shown).

5 is a cylindrical hole, and 6 is a hollow part.

The cylindrical rib 2 has the upper and lower cylindrical holes 5 each having the required length, the remaining middle part is the hollow part 6, and its shape is the 5th one.
As shown in the figure, it is a hollow body with a spherical shape cut off at both the upper and lower ends 5', and as shown in Figure 6, it has a beer barrel shape with a radius of curvature larger than the radius to form a spherical surface. Furthermore, as shown in FIG. 7, the radius of curvature is larger than the radius that would make it spherical when the distance between the upper and lower ends of the hollow part 6 becomes particularly large, and a slight cylindrical part is provided in the center. Figure 8 shows the case shown in Figure 7, with a beer barrel-shaped hollow body having a larger radius of curvature. This is an embodiment of the present invention in which the distance gradually decreases from the center toward the center.

In this way, defects caused by gas during casting or sink marks during solidification when casting the tray of the present invention can be almost eliminated, but depending on the size and shape of the tray, The best results can be obtained by appropriately selecting one of them.

Note that, without changing the gist of the present invention, in addition to the shape of the hollow part 6 shown in the embodiment, the shape of the hollow part 6 may be a combination of a truncated cone shape with the small end facing both the upper and lower ends. You can also.

As described above, heating and
The thermal strain during cooling can be sufficiently alleviated.

Furthermore, according to the present invention, the occurrence of cavities during casting is eliminated, and since the shape of the hollow part 6 is formed in such a way that it is difficult for coolant etc. to accumulate, it is possible to prevent the formation of cavities during casting. The cause of disturbance of the atmosphere in the furnace during heat treatment due to cooling liquid or the like can be eliminated.

The effects of the present invention are summarized as follows.

- Since the shape of the hollow part is such that core sand can be easily removed, the time required to remove sand after casting is shortened.

■ Cooling liquid, etc. is no longer stored in the tray, so during heating during heat treatment, there is less negative impact on the atmosphere inside the furnace due to evaporation, combustion, etc. of the cooling liquid, and the atmosphere inside the furnace can be maintained in a stable state. .

■ The cooling liquid, etc. can easily flow out from the meat crevice, etc., and will not accumulate in the holes, etc., so the consumption of the cooling liquid, etc. can be reduced.

■ The occurrence of casting defects can be greatly reduced, so
This further increases the durability of the tray and eliminates unnecessary work such as welding and repairing defective parts.

[Brief explanation of the drawing]

Figure 1 is a partially omitted plan view of the present invention, Figure 2 is A of Figure 1.
-A' sectional view, FIG. 3 is an enlarged longitudinal section of a conventional cylindrical rib, FIG. 4 is an enlarged longitudinal section of another conventional cylindrical rib, and FIGS. 5 to 8 are an enlarged longitudinal section of a conventional cylindrical rib. 2 is an enlarged vertical cross-sectional view of a cylindrical rib, taken along the line BB' in FIG. 1; FIG. 1... Peripheral frame, 2... Cylindrical rib, 3...
...Connecting rib, 4...Cavity part, 5...
... Cylindrical hole, 5' ... Above the hollow part 6,
Lower both ends, 6... Flesh area.

Claims (1)

[Scope of utility model registration request] In an integrally cast tray in which cylindrical ribs 2 having several cylindrical holes 5 are connected by connecting ribs 3 inside a peripheral frame 1, there is a hollow part in the middle of the inner surface of the cylindrical holes 5. 6, and the thickness thereof is formed so as to gradually decrease from the upper and lower ends 5' of the hollow portion 6 toward the center thereof.