JPS5819148Y2 - heat treatment furnace - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a heat treatment furnace used for forging, hardening, tempering, etc. a metal object to be heated.

The purpose of this is to significantly improve the durability of the hearth, eliminating the need for replacing or repairing the hearth, and even if some parts of the hearth become unusable due to damage, etc.
It is an object of the present invention to provide an inexpensive product which allows only the unusable parts to be easily replaced and further allows the slag of the metal material produced during heat treatment to flow easily.

Conventional heat treatment furnaces of this kind have a hearth made of firebrick, so the silicon carbide in the hearth brick material that comes into contact with the object to be heated reacts with the red-hot slag emitted from the metal material during heat treatment. Since high heat of about 2000° C. or more is generated, the hearth bricks melt or are damaged early, rendering them unusable and having poor durability.

As a result, the hearth bricks had to be repaired or replaced, reducing work efficiency and being uneconomical.

The hearth was integrally cast from heat-resistant cast steel, and the upper surface of the hearth was corrugated and the lower surface was flat.
According to the Matsufuru hearth described in Japanese Patent No.-31688, the above-mentioned drawbacks are solved.

However, since the hearth of this type is a monolithic casting, if a part of the hearth becomes unusable due to damage, the entire hearth must be replaced, which is not only uneconomical but also time-consuming and inconvenient. There is.

In addition, since the lower surface of the hearth is flat, this lower surface cannot be used as a surface on which objects to be heated are placed.

This idea eliminates the drawbacks and inconveniences of the conventional methods.
One embodiment thereof will be described below based on the drawings.

Reference numeral 1 denotes a heat treatment furnace body, and a furnace wall 2 of the heat treatment furnace body 1
A furnace interior 4 is formed by lining the inner peripheral surface of the furnace with a refractory heat insulating material 3 such as ceramic fiber or wool material.

In the figure, the front part of the furnace interior 4 is a preheating chamber 4a, and the rear part is a firing chamber 4b.

5 is a burner that quickly heats the firing chamber 4b, and 6 is a preheating burner that sends it to the preheating chamber 4a.

7 is a door lined with a fireproof insulation material such as ceramic fiber or wool material.

A slit-shaped inlet 9 corresponding to the upper surface of the hearth, which will be described later, is provided in the lower part of the front wall of the furnace interior 4, and an outlet 10 is provided in the lower part of the rear wall of the furnace interior 4, which is opposite to the inlet 9.

A hearth 8 with which the object to be heated M comes into contact is provided at the lower part of the furnace 4 between the outlet 10 and a little forward of the inlet 9. fixed hearths 8a, 8a that are protruding from each other in opposite directions in the center in the longitudinal direction and supporting both ends of the object to be heated M;
It consists of a fixed hearth 8a and a movable hearth 8b, which is installed in a space 11 formed between 8a and a movable hearth 8b that lifts a heated object M that is placed across the 8% space and gradually moves it forward toward the outlet 10. There is.

The movable hearth 8b includes an elevating device 12 located below the movable hearth 8b that raises and lowers the hearth 8b by the operation of a driving means (not shown).
A reciprocating device 13 is provided which is operated in synchronization with the lifting device 12 and moves the movable hearth 8b forward and backward.

Due to the related operation of the lifting device 12 and the reciprocating device 13, the movable hearth 8b rises within the space 11, and the movable hearth 8b rises in the space 11, and the movable hearth 8b rises in parallel over the fixed hearths 8a, 8a to receive heat during firing. The objects M are lifted all at once and transferred forward by l pitches, and at the forward end, the objects M to be heated are left on the fixed hearths 8a, 8a and lowered.
The object to be heated M is moved toward the exit 10 by retreating back to the original position and repeating a series of operations of raising, moving forward, lowering, and retreating again.

In the hearth 8, that is, the fixed hearth 8a, 2 rows of 8%, and the 1 row of movable hearth Bb, the areas that contact the heated object M and become very high temperature, that is, the upper part near the outlet 10, have high fire resistance. A large number of metal members 14 (see FIG. 4), which are subdivided bodies each having a substantially H-shaped cross section, are arranged in rows in the direction of movement of the object M to be heated.

That is, the upper and lower top surfaces of the left and right side walls 14a, 14b of the metal material 14, which is a substantially H-shaped subdivided body, are made into a wave shape, and the recesses 16 of the wave-shaped portions are inclined inward to form the slag distribution groove 1.
7, and the slag distribution groove 17 is connected to the slag passage 1.
It is connected with 8.

The metal material 14 made up of each of these subdivided bodies is buried in an amorphous clay-like plastic refractory 15 (for example, Plibrico, trade name) with its heated object mounting surface exposed.
It will be as follows.

Here, the highly fire-resistant metal material 14 is a special alloy (trade name) in which around 60% of its components are Cr, and which also contains C, Si, Mn, P, and S, as used in this example. Climax) or its component ratio is C
0.03%, Si 5.0%, Mn1.0%, Ni14
%, 20% Cr, 2% MO, ■ 1%, 3% CO, and a special alloy (trade name Silicolloy) consisting of the remainder Fe,
Other items may also be used.

In this embodiment, the metal material 14 and the clay-like plastic refractory 15 were provided in the high temperature part of the hearth 8.
It can also be extended to other locations.

Reference numeral 19 denotes a conveyor for feeding the objects M to be heated, which is provided in front of the entrance 9 of the heat treatment furnace main body 1, and the conveyor 19 scoops up the objects M to be heated one by one in the inclined material mounting table 20,
The heated object M falls onto the chute 21 at the reversing part of the conveyor 19, and is transferred down to the inclined surface of the chute 21 and transferred to the hearth 8.
It is guided to the front, fed into the hearth 8 through the inlet 9, and discharged through the outlet 10, thereby making it possible to automate the firing operation.

Reference numeral 22 denotes an escape chute provided at the outlet 10 of the furnace so that the material is transferred to a conveyor 23.

Reference numeral 24 denotes a blower, which is provided so that air is sent to the gap between the outlet 10, the movable hearth 8b, and the fixed hearth 8a through a blower pipe 25 connected to the blower 24. This prevents flames and heat from escaping through the gaps between the fixed hearth 8a and the movable hearth 8b, improves heat transfer within the furnace, and uniformly heats the material.

When heat-treating the object M, the object M is sent from the material mounting table 20 to the inlet 9 of the furnace via the conveyor 19.
is preheated in the preheating chamber 4a by the operation of the movable hearth 8b, then heat-treated at a desired temperature in the firing chamber 4b by the burner 5, and taken out from the outlet 10. When reaching the hearth 8 provided with the metal material 14, the heated object M has been sufficiently fired to produce a red-hot slag.

However, since the slag of the object to be heated M does not react with the metal material 14 of the hearth 8, the hearth 8 does not melt at all.

According to this invention having the above configuration, not only the hearth is formed of the metal material 14 having high fire resistance, but also the metal material 14 is
4 is formed by providing a large number of sub-divided bodies with approximately H-shaped cross sections in one or double rows in the direction of movement of the object to be heated M, and each of these sub-divided bodies is embedded in an irregularly shaped clay-like plastic refractory 15. Therefore, the hearth can be easily set up simply by embedding the metal material 14 in the refractory 15, resulting in good workability.

In addition, while it is easy to take out the metal material 14 from the refractory 15, if only the metal material 14 that is unusable due to damage etc. is replaced, it can be used semi-permanently, making it economical and easy to replace. It has the advantage of being easy to work with.

Further, since the metal material 14 consisting of subdivided bodies is formed with a substantially H-shaped cross section, the lower surface portion can be used if the upper surface portion becomes unusable, so that the durability of the metal material 14 is improved. As a result, the durability of the hearth can be greatly improved.

Further, the upper and lower top surfaces of the left and right side walls of each of the H-shaped and subdivided bodies are made wave-shaped, and the wave-shaped recesses 16 are inclined inward to form the slag circulation grooves 17. There is an advantage that the melted slag (slag) of the object to be heated M easily flows into the slag passage 18.

[Brief explanation of the drawing]

Each of the figures shows an embodiment of this invention. Figure 1 is a schematic vertical sectional view, Figure 2 is a cross-sectional view of Figure 1, and Figure 3 is a sectional view taken along the line A--A of Figure 1. , Figure 4 is an enlarged perspective view of the metal material,
Figure 5 is a plan view of Figure 4, Figure 6 is a right side view of Figure 4,
FIG. 7 is a front view of FIG. 4. 2... Hearth wall, 8... Hearth, 14...
...Metal material, 15...Clay-like plastic refractory, 17...Slag distribution groove, 18...
・Slag passage.

Claims (1)

[Scope of utility model registration request] In a heat treatment furnace in which the hearth in contact with the object to be heated is made of a highly refractory metal material, the metal material has a large number of subdivided bodies each having a substantially H-shaped cross section arranged in a single row or in double rows in the direction of movement of the object to be heated. established,
Each of these subdivisions is buried in an irregularly shaped clay-like plastic refractory, and the top and bottom surfaces of the left and right side walls of each of the H-shaped subdivisions are made into a corrugated shape, and the recesses of the corrugated portions are filled inside. A heat treatment furnace characterized in that a slag distribution groove is formed so as to be inclined in the opposite direction.