JPS6237107Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a heat treatment furnace, and particularly to an improvement of a heat treatment furnace in which the inner wall of the furnace is formed of a steel plate.

This type of heat treatment furnace is mainly used to heat treat aluminum alloys and the like, and the temperature inside the furnace is usually raised to around 550°C to heat the aluminum alloys and the like.

Conventionally, such a heat treatment furnace has been proposed as shown in FIG. , and a door 9 which can be opened and closed and is similarly formed by filling a heat insulating material 4 between an outer wall 6 and an inner wall 7.

Here, the inner wall 3 of the wall body 5 is formed by firmly fixing stainless steel plates 11 to inner plate frame ribs 10 arranged in a grid pattern at predetermined intervals by bolting or welding them from the back side. is common.

However, in such a heat treatment furnace 1, if the furnace length is l = 10 m, the temperature inside the furnace is set to room temperature t' =
When the temperature is raised from 20℃ to t=550℃, the elongation λ of the inner wall 3 is the linear expansion coefficient of the stainless steel plate 11, α=
Assuming 1.6×10 ^-5 , λ=α(t−t′)l=1.6×
10×(550−20)×10000≒85mm.

As a result, the stainless steel plate 11 may become wavy and deformed, and if the stainless steel plate 11 is fastened with bolts, the bolts may become deformed, resulting in poor airtightness of the furnace and increased heat loss. , since the inner plate frame bone 10 is always required for reinforcement, and this inner plate frame bone 10 itself also expands thermally,
A serious drawback was that the furnace itself would lose its shape after long-term use.

Furthermore, the furnace using the inner plate frame frame 10 has the disadvantages of being heavy and requiring a large number of assembly steps, and the inner plate frame frame 10 is also heated when the temperature is raised, so the heat capacity is low. It also had the disadvantage of requiring an additional amount of .

Therefore, the purpose of this invention is to eliminate all of these drawbacks of the conventional technology at once.Specifically, the furnace inner wall is formed by bending each side edge of a steel plate of a predetermined size. By connecting a plurality of bodies and joining the mutually contacting bent edges of the box-like bodies to form an integral body, it imparts shape-retaining force to itself and eliminates the conventional inner plate frame. The aim is to significantly improve airtightness and eliminate the drawbacks of the conventional technology.

To achieve this objective, the present invention provides a heat treatment furnace in which the inner wall of the furnace is formed of a steel plate, in which a box-shaped body is formed of the steel plate, which has a flat plate part and a side plate part bent from the periphery of the plate part toward the furnace wall side. , a furnace inner wall is formed by connecting a plurality of box-shaped bodies and joining the edge of the side plate of each box-shaped body to the edge of the side plate of the connected box-shaped body. .

Hereinafter, the present invention will be explained based on embodiments shown in the drawings.

Fig. 2 is a sectional view showing an example of the present invention, and Fig. 3 is a perspective view of the inner wall of the furnace as seen from the back side. Parts corresponding to those in Fig. 1 above are designated by the same reference numerals, and detailed explanation thereof will be omitted. Omitted.

In the figure, the reference numeral 15 denotes a heating element disposed at a predetermined interval inside the inner wall 3, and the reference numeral 16 denotes a Matsufuru plate disposed inside the heating element 15, which has a Matsufuru furnace structure as a whole.

The inner wall 3 of the wall body 5 has a plurality of box-like bodies 20 formed of, for example, rectangular stainless steel plates. The box-shaped bodies 20 are connected so as to be located in the same plane, and are joined by welding (22) the entire circumference of the bent edges 21 of the mutually connected side plate portions 19 of the box-shaped bodies 20 to form an integral structure.

Here, each box-like body 20 is selected so that the bending angle of its side plate portion 19 is slightly smaller than 90 degrees, and therefore, each box-like body 20 connected with the bent edge 21 is welded. A slight gap 23 is formed between the flat plate parts 18.

Reference numeral 24 denotes a connecting rod fixed to a corner of the box-shaped body 20 by welding or the like, and its free end is slidably supported by a support portion 25 formed in advance on the outer wall 2, so that the furnace is heated by thermal expansion. Inner wall 3 to the inside
The structure is configured to allow for the expansion of the bulge.

In addition, at the connecting position of the inner wall 3 at the corner of the wall 5, the side plate parts 19 of the box-shaped body 20 forming the ends of the inner walls 3 that are connected to each other are fixed to the pillars 26 disposed at the corner. and are connected via the support column 26.

The above is an example of the configuration of the present invention, and its operation will be explained next.

When the temperature inside the furnace is maintained at room temperature, a gap 23 is formed between the flat plate parts 18 of each box-shaped body 20 forming the inner wall 3 of the wall body 5, and in this state, the door 9 is opened. After the object to be heat treated is inserted into the heat treatment furnace 1, the door 9 is closed and the heating element 15 is activated to start raising the temperature.

As a result, the temperature inside the furnace gradually increases,
Although each box-like body 20 will thermally expand, the slight expansion of the flat plate portion 18 of each box-like body 20 at the initial stage of temperature rise is absorbed by the gap 23 formed between each box-like body 20. The inner wall surface will not be deformed.

Then, by continuing to raise the temperature, the flat plate portion 1 of each box-shaped body 20 is heated.
8 becomes zero, and the adjacent box-shaped bodies 2
When the flat plate parts 18 of 0 come into contact with each other, each flat plate part 18 stretches due to thermal expansion, so that the inner wall 3 becomes a box-like shape disposed at the center of the box-like body 20 that constitutes them. It bulges out into the furnace with the body 20 as the apex.

At this time, the box-shaped body 20 has the conrod 24 connected to the outer wall 2.
Since it is slidably supported by the support part 25 of the weld part 25, the weld part 22 is smoothly bulged out without causing large distortion, and therefore the weld part 22 is not deformed without applying excessive force to the weld part 22. Airtightness can be maintained reliably without any fear of cracks occurring in the joint.

Further, since a portion of the elongation of the inner wall 3 as a whole is absorbed by the gap 23, it can be reduced compared to the conventional example.

Thereafter, when the temperature increase is stopped and the door 9 is opened to take out the object to be heat-treated outside and the temperature inside the furnace is lowered to room temperature, each box-shaped body 20 is lowered as the temperature lowers, contrary to the above. As a result, the bulge of the inner wall 3 gradually decreases, and a gap 23 is created between the flat plate portions 18 of each box-shaped body 20, so that each box-shaped body 20 returns to its original position.

In addition, since the connecting rod 24 smoothly slides outward at this time, no unnecessary external force is applied to the box-shaped body 20, and therefore no plastic deformation occurs.

In addition, in the above-mentioned embodiment, the case where the box-like body 20 is formed by bending each side edge of the stainless steel plate 11 so that the flat plate part 18 is formed into a square has been described. It may be formed as follows.

In addition, in the embodiment, the case where each box-like body 20 was manufactured individually and joined by welding was explained, but the present invention is not limited to this. The inner wall 3 can also be formed by forming a plurality of box-shaped bodies 20 and welding a required number of them.

Furthermore, in the present invention, it is not necessarily necessary to form the gaps 23 between the connected box-like bodies 20, and the side plate portions 19 of the respective box-like bodies 20 may be closely connected to each other.

As described above, according to the present invention, a box-shaped body is formed by bending the side edges of a steel plate, and a plurality of the box-shaped bodies are connected and their mutually contacting bent edges are joined to form an inner wall. Because they are integrally formed, the mechanical strength of the box itself is high, and the mechanical strength of the entire inner wall is extremely high by joining and integrating them. There is no need for reinforcing members such as inner plate frame ribs as in the past, and material costs, assembly man-hours, weight, heat capacity, etc. can be significantly reduced, and even if there is elongation due to thermal expansion when the temperature rises, Since this is converted into a bulging length to the inside of the furnace, there is no local stress concentration, no distortion or damage, and there is no risk of the inner wall losing its shape, which is an extremely excellent effect.

Furthermore, since the bent edges of the box-shaped body are joined by welding or the like, airtightness is maintained even when the inner wall bulges into the furnace, which is an excellent feature that reduces heat loss. It also has effects.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway perspective view of a conventional heat treatment furnace, and FIG. 2 is a sectional view showing an embodiment of the present invention.
FIG. 3 is a perspective view of the inner wall seen from the back side. Explanation of symbols, 1...Heat treatment furnace, 2...Outer wall, 3
... Inner wall, 4 ... Heat insulating material, 9 ... Door, 20 ... Box-like body, 21 ... Bent edge, 22 ... Welded part, 24
...Conrod.

Claims (1)

[Scope of utility model registration request] In a heat treatment furnace in which the inner wall of the furnace is formed of a steel plate, a box-shaped body having a flat plate part and a side plate part bent from the periphery of the steel plate toward the furnace wall side is formed, and a plurality of the box-shaped bodies are connected and A heat treatment furnace characterized in that the edge of the side plate of each box-shaped body is joined to the edge of the side plate of the adjacent box-shaped body to form an inner wall of the furnace.