JP2002173708A - High speed heating-up furnace - Google Patents

Abstract

PROBLEM TO BE SOLVED: To structurally improve heating-up efficiency to a work by eliminating any disturbing structure in hot blast circulating path in a furnace chamber. SOLUTION: In a high speed heating-up furnace for heating up the work W at high speed by coaxially disposing a cylindrical work holding chamber 3 in the furnace chamber 2 and forcibly convecting the hot blast generated with a burner B as eddy current with a circulating fan 4, a door 7 is arranged at a second work carrying port 35 in the work holding chamber 3. Then, the circulating path for uniformly circulating the hot blast over the whole circumference between the furnace chamber 2 and the work holding chamber 3, is secured by closing the door 7.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-speed heating furnace for rapidly heating a workpiece to a predetermined heat treatment temperature by circulating hot air, and more particularly, to a structurally more efficient heating furnace. A good fast heating furnace.

[0002]

2. Description of the Related Art The strength, moldability and other properties of an aluminum alloy can be adjusted by cold working, solution treatment, age hardening, annealing, etc., and its physical properties are low density, high rigidity, and high strength. It is widely used in aircraft, vehicles, etc. as a substitute for iron due to its workability.

[0003] Among them, 2000-series (Al-Cu) alloys and 5000-series (Al-Mg) series alloys are typical aluminum alloys in which solid solution strengthening and age hardening, which are typical physical properties of aluminum alloys, remarkably appear. Are known. These alloys can be subjected to T4 treatment (solution treatment → natural aging) or T6 treatment (solution treatment → artificial aging) after forming to obtain strength and rigidity comparable to iron.

[0004] The solution treatment is a process for obtaining a supersaturated solid solution by holding a work in a solid solution temperature range in a metal phase diagram, dissolving a precipitated phase in a matrix, and then quenching. . According to this, since the vacancy concentration is frozen in a supersaturated state, dispersion strengthening works strongly by the pinning action of the precipitated phase with respect to the mother phase by the subsequent aging treatment, and the strength of the material is dramatically improved. .

[0005] Incidentally, high work strains such as dislocations are accumulated in a work such as a forged product or a cold-worked product. In the case where the work is subjected to the solution treatment in this state, there is a finding that the shorter the heating time of the work, the better. In other words, after processing, the thermal expansion stress (diffusion coefficient) due to the mass difference between the workpieces is partially non-uniform due to the processing strain, and the recovery speed of the crystal becomes non-uniform, and the quality varies due to elasto-plastic deformation. Occurs. Therefore, the temperature of the work is rapidly raised to minimize the variation.

[0006] Therefore, in some solution treatment steps, a solution treatment is performed by combining a high-speed heating furnace and a holding furnace for rapidly and uniformly heating a workpiece. FIG. 4 shows an example of a high-speed heating furnace. This high-temperature heating furnace 1 is surrounded by a refractory wall 21 having a work entrance 22 on a side surface and a furnace chamber 2 provided with a heating means B such as a burner at a lower portion.
And a cylindrical work storage chamber 3 arranged concentrically in the furnace chamber 2 and a circulation fan (radial fan) 4 provided on the upper opening 33 side of the work storage chamber 3.

A mounting shelf 31 for mounting the work W is provided inside the work storage chamber 3, and a work transfer path 32 communicating with the work transfer port 22 of the furnace chamber 2 in parallel with the mounting shelf 31. Are provided integrally. A door D for closing the work transfer port 22 is provided on the outer wall surface of the work transfer port 22 so as to be openable and closable.

By operating the circulation fan 4, the hot air in the work storage chamber 3 directly heated by the heating means B is sucked up from the upper opening 33 and circulated between the furnace chamber 2 and the work storage chamber 3. After descending as a vortex in the passage 5, the work storage chamber 3 is again heated together with the burner flame of the heating means B.
Is guided to the work storage room 3 through the lower opening 34 of the work.

According to this, the atmosphere in the furnace chamber 2 including the work storage chamber 3 is rapidly heated, and the work W in the work storage chamber 3 is rapidly and uniformly heated to a desired heat treatment temperature. Became possible.

[0010]

However, in order to further increase the efficiency of raising the temperature of the work W, in the above-described conventional configuration, the work transfer path 32 is provided in the circulation passage 5 of the hot air sent from the circulation fan 4. Therefore, the work conveyance path 32 becomes a resistance, and the vortex generated by the circulation fan 4 cannot be uniformly lowered.
There is a possibility that the flow rate to the lower opening 32 and the uniformity may become non-uniform.

When the eddy current generated downward is guided again upward into the work storage chamber 3, part of the hot air stagnates in the vicinity of the lower opening 34 of the work storage chamber 3, causing turbulence. This turbulent flow may also cause inflow resistance into the work storage chamber 3.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem, and an object of the present invention is to eliminate an obstacle that obstructs a hot air circulation path in a furnace chamber, and to structurally enhance a temperature rising efficiency of a work. It is an object of the present invention to provide a high-speed heating furnace that can perform the heating.

[0013]

In order to achieve the above-mentioned object, the present invention relates to a furnace room which is surrounded by a refractory wall having a work transfer port and provided with a heating means such as a burner toward the inside thereof. A cylindrical work storage chamber provided concentrically with a predetermined gap from its inner wall surface in the furnace chamber and provided with a mounting shelf for mounting a work therein, and the furnace heated by the heating means. In a high-speed heating furnace having a circulation fan for forcibly circulating the atmosphere in the room via the work storage chamber, the work storage chamber is disposed to face the work transfer port of the furnace chamber. A second work transfer port, wherein the second work transfer port is provided with an openable and closable door, and when the door is in a closed state, a gap between the inner wall of the furnace chamber and the outer wall of the work storage chamber is provided. The above atmosphere circulates all around It is characterized in that the ring passage is ensured.

According to this, the door is closed when the work is heated, and there is no air resistance in the circulation passage provided between the furnace chamber and the work storage chamber. Circulation is obtained.

In the present invention, it is preferable in design that the door can be opened and closed in a double-opening manner toward the workpiece transfer port of the furnace chamber. In addition, a sliding door that slides along the workpiece storage chamber is preferable. There is no particular limitation as long as the door is closed along the work storage chamber when the door is in the closed state.

In order to more efficiently introduce the hot air circulated in the furnace chamber into the work storage chamber, the suction side of the storage chamber is provided with the atmosphere generated in a vortex by the circulation fan in the circulation passage. It is preferable to provide a rectifying plate for maintaining the vortex when the vortex is guided through the storage chamber through the storage chamber.

Preferably, the rectifying plate is provided in an arc shape so as to converge in an axial direction from an outer peripheral direction of the storage chamber in the same direction as a rotation direction of the circulating fan. The eddy current is further accelerated and guided into the work storage chamber, and as a result, the temperature rise efficiency of the work is increased.

[0018]

Next, an embodiment of the present invention will be described. FIG. 1 is a side sectional view schematically showing a high-speed heating furnace according to this embodiment. Note that the same reference numerals are used for components which are the same as or are considered to be the same as those of the conventional device of FIG. 4 described above.

The high-speed heating furnace 1a is surrounded by a refractory wall 21 having a work transfer port 22 (hereinafter, referred to as a first work transfer port) on a side surface, and a heating means B such as a burner is provided toward the inside thereof. Furnace chamber 2, a cylindrical work storage chamber 3 disposed concentrically in the furnace chamber 2, and a circulation fan (radial fan) 4 disposed on the upper opening 33 side of the work storage chamber 3. ing.

At the front of the first work transfer port 22 of the furnace chamber 2, a furnace chamber door D for opening and closing the first work transfer port 22 is provided. In this embodiment, the furnace chamber door D is connected to elevating means (not shown) and slides up and down in the vertical direction when the workpiece W is transported. The opening and closing mechanism of the furnace chamber door D is not particularly limited.

In this embodiment, the heating means B is composed of a high calorie burner using city gas or the like, and is coaxially disposed below the furnace chamber 2 so as to blow out a burner flame toward the lower opening 34 of the work storage section 3. Are located in

The work storage chamber 3 is made of a heat-resistant metal cylinder (both may be a rectangular cylinder) having both ends opened.
It is arranged concentrically at the center of the furnace chamber 2 at a predetermined distance from the inner peripheral surface 23 of the furnace chamber 2 by a bracket (not shown). A mounting shelf 31 on which the work W is mounted is provided inside the work storage chamber 3. In this embodiment, the mounting shelf 31 is provided in the shape of a cage parallel to the transfer direction of the work W (see FIG. 2).

A second work transfer port 35 for transferring the work W into the work storage chamber 3 is provided on a side surface of the work storage chamber 3 facing the first work transfer port 22 of the furnace chamber 2. In this embodiment, the second work transfer port 35
Are opened so as to have substantially the same opening width and opening height as the first work transfer port 22.

As shown in FIG. 2 (a sectional view taken along the line AA in FIG. 1), the second work transfer port 35 is provided with a work storage chamber door 7 for opening and closing the opening. The work storage room door 7 is formed in an arc shape along the outer peripheral wall of the storage room 3.
In this embodiment, each of the doors 71a and 71b is attached to the first work transfer port 22 so as to be openable and closable in a double-opening manner.

The doors 71a and 71b and the storage room 3 are connected by hinges 73 and 73, respectively.
Reference numerals a and 71b are connected to a door opening / closing means such as a motor provided outside the furnace chamber 2 via an opening / closing shaft 72. In this embodiment, it is preferable that the hinge portion 73 is formed in a shape that minimizes the resistance of hot air. Further, the inner wall 23 of the furnace chamber 2 is preferably formed in a cylindrical shape along the outer peripheral surface of the work storage chamber 3.

According to this, when each of the doors 71a and 71b is in the closed state, the hot air generated by the circulation fan 4 is provided between the furnace chamber 2 and the work storage chamber 3 over the entire circumference thereof. A circulation passage 5 for circulating the inside is secured. That is, since there is nothing to block the circulation passage 5, hot air can stably pass to the lower part of the storage room 3.

A rectifying plate 6 for further accelerating the vortex circulating in the work storage chamber 3 is provided on the lower opening 34 side of the work storage chamber 3. As shown in FIG. 3, the current plate 6 includes a number of blades 61 that converge in an arc shape from the outer peripheral direction of the storage chamber 3 to the axial direction.

In this embodiment, the blade 61 is converged in the same direction as the rotation direction of the circulation fan 4, whereby a vortex in the same rotation direction as the rotation direction of the circulation fan 4 is generated inside the storage chamber 3. The hot air can circulate in the storage room 3 without resistance. Further, a reinforcing rib 62 is provided below the current plate 6 so as to project in the burner B direction.

Referring again to FIG. 1, the circulating fan 4 includes a fan main body 41 having a U-shaped cross section open at the lower side, and a rotating shaft 42 transmitting torque to the fan main body 41. In this embodiment, the fan main body 41 is composed of a radial fan having a large number of blades (not shown) provided on a peripheral edge thereof, and by rotating a rotary shaft 42 connected to a driving means (not shown), sucks up hot air in the work storage chamber 3. Are blown into the circulation passage 5 between the furnace chamber 2 and the work storage chamber 3.

A series of operations of the high-speed heating furnace 1 configured as described above will be described. Furnace chamber 2 by circulation fan 4
The furnace chamber door D and the work storage chamber door 7 are opened in a state where hot air of a predetermined temperature is circulated in the inside, and the work W held by the transfer means (not shown) is transferred from the first transfer port 22 to the second transfer port 35. Then, the work storage room door 7 and the furnace room door D are closed after being placed on the mounting shelf 31 in the work storage room 3 via. The opening / closing order may be such that the furnace chamber door D side or the work storage chamber door 7 side first.

In any case, since the work storage door 7 is closed, a substantially uniform circulation passage 5 is secured between the furnace chamber 2 and the work storage chamber 3 over the entire circumference.
The hot air is swirled and circulates in the furnace, so that the workpiece W can be heated to a desired processing temperature in a high-speed and stable state. After the temperature of the work W is increased, the work W is again transferred to the work transfer port 2.
It is taken out of the furnace through 2 and 25 and transferred to a holding furnace (not shown).

In the above embodiment, the work storage room door 7
Is constituted by a double door, but it may be a sliding door which can be opened and closed along the work storage chamber 3 as long as it does not obstruct the circulation passage 5 when closed. It is.

In the above embodiment, one work W is mounted on the mounting shelf 31. However, a plurality of works W may be mounted with a larger diameter. . In this case, when taking out the work W,
May be configured as a turntable, and such an embodiment is also included in the present invention.

[0034]

As described above, according to the present invention,
In a high-speed heating furnace in which the temperature is rapidly raised by circulating the work with hot air, there is no resistance in the circulation passage between the furnace chamber and the work storage chamber, so that the work can be heated more efficiently. .

Further, by providing a rectifying plate at the lower end of the work storage chamber to generate a strong eddy current in the work storage chamber, the temperature raising efficiency can be further improved.

[Brief description of the drawings]

FIG. 1 is a side sectional view of a fast heating furnace according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG. 1;

FIG. 3 is a sectional view taken along line BB of FIG. 1;

FIG. 4 is a side sectional view of a conventional high-speed heating furnace.

[Explanation of symbols]

 1a High-speed heating furnace 2 Furnace room 21 Refractory wall 22 First work transfer port 3 Work storage chamber 31 Mounting shelf 32 Work transfer path 33 Upper opening 34 Lower opening 35 Second work transfer port 4 Circulation fan 41 Circulating fan body 42 Rotation Shaft 5 Circulation passage 6 Rectifier plate 61 Blade 7 Work storage room door 71a, 71b Door body 72 Opening / closing shaft 73 Hinge D Furnace room door B Heating means

Claims (4)

[Claims] 1. A furnace room surrounded by a refractory wall having a work transfer port and provided with heating means such as a burner toward the inside thereof, and concentric with a predetermined gap from the inner wall surface in the furnace room. And a cylindrical work storage chamber in which a mounting shelf for mounting a work is provided, and the atmosphere in the furnace chamber heated by the heating means is forcibly passed through the work storage chamber. A high-speed heating furnace provided with a circulating fan that circulates, wherein the work storage chamber has a second work transfer port disposed opposite to the work transfer port of the furnace chamber;
The work transfer port is provided with a door that can be opened and closed, and when the door is in a closed state, a circulation passage through which the atmosphere circulates over the entire circumference between the inner wall of the furnace chamber and the outer wall of the work storage chamber is secured. A high-speed heating furnace. 2. The high-temperature heating furnace according to claim 1, wherein the door can be opened and closed in a double-opening manner toward the workpiece transfer port of the furnace chamber. 3. A rectifying plate on the suction side of the storage chamber for maintaining the vortex when the atmosphere generated in a vortex by the circulation fan is guided to the storage chamber through the circulation passage. The high-speed heating furnace according to claim 1 or 2, further comprising: 4. The high-speed riser according to claim 3, wherein the rectifying plate is provided in an arc shape so as to converge in an axial direction from an outer peripheral direction of the storage chamber in the same direction as the rotation direction of the circulation fan. Fireplace.