JPH0328316A - Roller hearth type heat treating furnace - Google Patents

Abstract

PURPOSE:To rapidly switch the change in the atmosphere and temp. in the heat treating furnace for steel products and the transporting speeds of the steel products by a change in steel kind and to continuously and efficiently heat-treat the steel products of different kinds under optimum conditions respectively, by dividing transporting rollers in the furnace to plural groups which are respectively independently driving and providing partition walls in the furnace. CONSTITUTION:The many rollers 8 are provided in the heat-treating furnace body 1 for the steel products Wn. A charging vestibule 2 and an ejection vestibule 3 are provided at the front and rear ends of the furnace and the plural partition doors 9a to 9i are provided in the furnace. The roller groups A1 to A4 and B1 to B4 can be respectively independently driven. The billets Wn to be treated are transferred from the inside of the charging vestibule 2 onto the roller group B1 and are transported via B4 to the roller group (from A4 to A1). The billets of the different kinds charged one after another to the furnace during this process are subjected to the heat treatments optimal for the billets of the different kinds in plural block chambers R1 to R8 segmented by the respective partition doors 9a to 9i by adequately controlling the atmosphere gases, temps. and the transporting speeds by the respective roller groups. The treated billets are taken out by the ejection vestibule of the heat treating furnace.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention is applicable to cases where the furnace atmosphere and/or furnace temperature, which are heat treatment conditions, are changed due to changes in the steel type of the treated material, etc.
Quickly change the furnace atmosphere and/or furnace temperature.
The present invention also relates to a roller hearth type heat treatment furnace that can shorten the empty furnace time.

(Prior art) In a conventional roller hearth type heat treatment furnace, when changing the heat treatment conditions such as the composition of the atmosphere in the furnace, the set temperature in the furnace, and the conveyance speed in the furnace due to changes in the material to be treated, it is necessary to change the previously treated material. After being extracted outside the furnace, the temperature, atmosphere, and conveyance speed for each zone in the furnace were changed to correspond to the heat treatment conditions of the modified material, and the modified material was charged into the furnace and heat-treated.

(Problems to be Solved) However, the conventional roller hearth heat treatment furnace described above generally does not have a partition door inside the furnace, and does not have a mechanism for partially varying the conveyance speed.

Therefore, as mentioned above, when changing the heat treatment conditions, it is necessary to first empty the heat treatment furnace and change the furnace temperature, atmosphere, and conveyance speed before charging the treated material, which increases the operating rate. However, there is a problem in that the total fuel consumption rate increases as well.

By the way, in recent years, the present applicant has issued a Japanese Patent Publication No. 58-42242.
The publication describes a roller hearth type in which the in-furnace conveyance rollers are made up of multiple roller groups and these are sequentially driven independently, allowing materials to be treated with different heat cycles to coexist in the same furnace and efficiently heat-treating materials with minimal loss time. A heat treatment furnace has been proposed.

However, in this proposal, the transport speed of the treated material, that is, the heat cycle itself, can be adjusted to match the treated material, but other requirements for the heat treatment conditions of the treated material, such as the furnace atmosphere and/or It cannot adequately respond to changes in temperature.

As a result of reexamining this roller hearth type heat treatment furnace, the present inventors found that when heat treating materials with different conveyance speeds are mixed in the same furnace,
, 3, a space of at least 1 zone (1 roller group) is finally formed on the extraction side between the preceding treated material and the subsequently treated material.

Therefore, in the present invention, if the space is finally divided by a partition door and the temperature and atmosphere of this partition space are changed, the furnace atmosphere and/or the furnace temperature due to the change in the heat treatment conditions can be changed. It has been found that it is possible to change the furnace without having to make it an empty furnace once.

(Means for Solving the Problems) The roller hearth type heat treatment furnace according to the present invention has been made in consideration of the above points, and the in-furnace conveyance roller is divided into a plurality of independently driven roller groups, and A partition door is provided at at least two dividing points of the group, and when the heat treatment conditions are changed, the partition door creates a furnace atmosphere and atmosphere corresponding to the subsequent treatment material between the preceding treatment material group and the subsequent treatment material group. /Or a zone is formed to change the temperature inside the furnace.

(Example) Next, the present invention will be explained according to the drawings which are one example.

FIG. 1 is a schematic explanatory diagram of a roller hearth type heat treatment furnace according to the present invention, in which two vestibules are placed on both sides of the furnace body l.
and Extract Bestible 3. And the furnace body 1
The in-furnace conveyance rollers in the furnace are comprised of a plurality of roller groups A + ~A
4 and B, -B. The roller group is divided into two groups, and each roller group is driven independently of each other.

Each of the roller groups A, A4, and B. From B4
As the length increases, each roller group A l
"'-A 4 1 B l"" B 4 1 Roller groups C, D of charging bestible 2 and extraction bestible 3
Each of the drive rollers 8 includes a reducer 4, a chain 5,
It is connected to one drive shaft 7 by a sprocket 6.

An electromagnetic clutch K is provided between each of the subrockets 6 of the drive shaft 7. - K8 is provided, and a charging drive motor M3 and an extraction drive motor M4 are provided at both ends, and an electromagnetic clutch KM is provided between the drive sprocket 6 of the roller group B and the electromagnetic clutch K. ．． The in-furnace roller drive motor M, is connected between the drive subrocket 6 of the roller group A and the electromagnetic clutch K6 via an electromagnetic clutch KM. In-furnace roller drive motors M, are connected through the respective in-furnace roller drive motors M, respectively.

Further, the roller groups C and B, . Partition doors 9a, 9b, . . . 91 are provided at the dividing points of the adjacent roller groups below B2, and each partition door 9a, 9b, . ,R. ,...R8 can be formed.

Furthermore, each compartment R I + R2 + ... R8
is provided with atmosphere supply means (not shown) and indirect heating means (not shown).

The roller hearth type heat treatment furnace according to the present invention has the above-mentioned configuration, and a method of operating the furnace will be explained next.

[1] When continuously processing the same material, first open the partition doors 9b to 9h to communicate with each chamber R, to R8, and supply exothermic gas (Nx gas), Provide a protective atmosphere such as endothermic gas (Rx gas). And electromagnetic clutch K. ON, K, OFF,
By opening the partition door 9a, the charging drive motor M3 is driven, and the material to be processed in the charging bestible 2 is transferred to the charging roller.
Group A is transported upwards at high speed. Next, electromagnetic Kuranochi K
．． OFF, K. is turned ON, the partition door 9a is left open, and the processing material on the furnace roller group B is moved from the furnace inlet to the roller drive motor M.
1, they are sequentially conveyed to the extraction side at a predetermined speed. and,
When the treated material has completely moved onto the roller group B,
Again, the electromagnetic clutch K. ON. K is turned OFF, the partition 9a is opened, and the material to be processed in the charging bestiple 2 is transported onto the roller group B at high speed. Therefore, the processing materials are sequentially transported through the furnace while maintaining predetermined intervals.

In this way, when the processing material reaches the extraction end roller group Δ1, the electromagnetic clutches K, FF, K. ○N, the partition door 91 is opened, and the reroller group A. The above treated material is extracted into the extraction bestible 3 at high speed. When this extraction is completed, turn on the electromagnetic clutch K, and turn on the electromagnetic clutch K. OFF
, the partition door 91 is opened and the processing material on the roller group A in the furnace is conveyed to the roller group A, while the extraction bestible 3
The processing materials inside the furnace are carried out to the extraction port roller by the extraction-only drive motor M4, and thereafter, the processing materials are successively transported onto the extraction table outside the furnace in the same manner.

[11] When charging high-speed conveyance treatment material with a different mesh type following low-speed conveyance treatment material In this case, first, the furnace roller drive motors M, M! As mentioned above, the previous low-speed processing material is charged into the furnace and processed in sequence by turning on the electromagnetic clutch K7, turning off KIl, opening the partition door 91, and the extraction drive motor M4. The wood is extracted.

When the final treated material Wn reaches a predetermined position on the roller group B, for example (see FIG. 2B), the partition doors 9a and 9d are closed and the compartments R, , R, , R3 are connected to a series of chambers. The atmosphere in the chamber is made suitable for the material to be subsequently treated, and the indirect heating means is controlled to change the furnace temperature. Then, while turning off the electromagnetic clutch K3 and continuing extraction by the furnace roller drive motor M, the partition door 9a is opened and the electromagnetic clutch K is turned off. is turned ON and K is turned OFF, and the first processed material W of the subsequent high-speed processing material charged into the charging bestible 2 is transferred to the in-furnace roller group B. by the charging drive motor M. high-speed charging onto the top.

Then, turn off the electromagnetic clutch K0. Turn on K+, leave the partition door 9a idle, and turn on the furnace roller drive motor M,
is switched to high speed, and the processing material on roller group B is conveyed to the extraction side at a predetermined speed. Thereafter, the material for subsequent treatment is charged into the furnace in the same manner.

When the pre-treated material Wn moves onto the roller group A4, the partition door 9e is closed, the atmosphere and furnace temperature of the compartment R4 formed by the partition doors 9d and 9e are changed in the same manner as described above, and then the partition door 9e is closed. While the door 9d is opened, the electromagnetic clutch K4 is turned off, and the subsequent processing materials W and + are charged into the compartment R4.

In this way, when the pre-treated material Wn is transferred onto the roller group A3, the partition door 9f is closed, and the partition room R is formed by the partition doors 9e and 9f, and the atmosphere inside the partition room R is changed as described above. Change the furnace temperature. Thereafter, the partition door 9e is opened, and the electromagnetic clutch K4 is turned ON, while the electromagnetic clutch K is turned OFF, and the processing material WI° is transferred to the compartment R.
, (see Figure 2 C). Similarly, when the previously treated material Wn moves to the roller group A (the treated material W,+ is located in the compartment R), the partition door 9g is left open, and the compartment R6 is opened by the partition doors 9f and 9g. , change the atmosphere and furnace temperature in the compartment R6, open the partition H9f, and turn on the electromagnetic clutch K5. With OFF,
The subsequent treatment material W,'' is charged into the compartment R6 (see FIG. 2-2).

Then, when the pre-treated material Wn moves to the extraction end roller group Δ1 (the treated material W,'' is located above the roller group A), a compartment R7 is formed as described above to change the atmosphere and furnace temperature,
Open the partition door 9g and turn on the electromagnetic clutch K. ON, K7 OFF
F and electromagnetic clutch KM! (See Figure 2 E).

Thereafter, the same operation is carried out, and the processing material Wn on the furnace roller group A is transferred to the extracted rice stabilizer 3 by the extraction-only drive motor M4 by turning off the electromagnetic clutch K7 and turning on K8 (No. (See Figure 2). Next, the processing material wn
is conveyed to the extraction roller table, the electromagnetic clutch K
7 ON, K. is turned OFF, the treated material WI' is sequentially conveyed onto the roller group A1, and from then on, the entire interior of the furnace becomes the subsequent treated material. When the inside of the furnace is completely replaced with the subsequent treatment material in this way, the electromagnetic clutch KM. is OFF, KM,
is turned ON, and the furnace roller drive motor M is switched to high speed, and the furnace roller group is driven and conveyed by this furnace roller drive motor M.

[111] When charging a material to be transported at a different speed and treated at a different steel type following a material to be transported at a high speed, the in-furnace personnel for the preceding treatment material, which is a material to be transported at a high speed, and the subsequent treatment material, which is a material to be transported at a low speed, will be described first. .

In this case, the pre-treated material is charged in the same manner as above, and when the final processed material Wn of the pre-treated material leaves the charging end roller group B and transfers to the roller group B, the electromagnetic clutch K,
OFF, the partition door 9b is opened, the pre-processed material is conveyed at high speed by the in-furnace roller drive motor M, and is sequentially extracted from the extraction bestible 3, while the subsequent processing material in the charging bestible 2 is transported by the charging-dedicated drive motor M3. W1° is loaded into roller group B at high speed (see Figure 3 C). Then, when the preceding final processing material Wn moves to the roller group B3, the partition door 9c is opened and the subsequent processing material W1' is located on the roller group B1, so the electromagnetic clutch K, is turned OFF, and the electromagnetic clutch K, is turned OFF.
N, the partition door 9b is opened, and the in-furnace roller drive motor M1, which has been switched to low speed, moves the subsequently processed material W,' to the roller group B,
Also, the pre-treated material Wn moves onto the roller group B4 (see FIG. 3-2).

Hereinafter, when the treated material Wn moves onto the furnace roller details B4,
Turn off the electromagnetic clutch K3, turn on K, leave the partition door 9d, and move the pre-treated material Wn to the roller r! ￥ When moving to A4, turn off electromagnetic clutch K4, turn on K3, and turn on partition door 9e.
(see the third illustration).

Then, when the pre-processed material Wn is extracted onto the extraction roller table, the electromagnetic clutch K4 is turned on, the partition door 9e is opened, and the electromagnetic clutch KM is turned off.
Furnace roller drive motor M. The treated material W° is transported into the furnace.

In this way, in order to charge the subsequent processing material, which is a low-speed transport material, into the furnace following the preceding processing material, which is a high-speed transport material, when the high-speed transport material leaves the in-furnace roller group B1, the low-speed transport material All you have to do is charge it.

As is clear from the above description, spaces corresponding to the number of l roller groups are formed between the preceding treatment material and the subsequent treatment material.

Therefore, when a space is formed, the front and rear partition doors are left open to form a compartment, and the charging side partition door is opened after changing the atmosphere and temperature in this compartment to an atmosphere and temperature suitable for the subsequent material to be transported. It is.

However, if the state shown in Fig. 3(v) occurs, the partition doors 9f to 9
1 is opened, '9e and '91 form a compartment, and the atmosphere and temperature of this part are changed.

In the above embodiment, the charging/extracting vestibule is included;
In addition, the case of high-speed charging and high-speed extraction of processing materials is explained, and each furnace inlet-ra drive motor is connected to a clutch K.
, and K, and between K6 and K, but do not have a charging/extraction bestible, or a high-speed charging furnace. When high-speed extraction is not required, each in-furnace roller drive motor is
It is sufficient to connect each to both ends of the drive shaft.

In the above embodiment, the in-furnace conveyance roller is B. ~B. ，
A. ~ A, and a partition door is provided at each dividing point of the in-furnace conveyance roller, but the present invention is not limited to this. It is sufficient that one empty compartment is formed between the partition doors.

(Effects of the Invention) As is clear from the above description, according to the present invention, the in-furnace conveyance roller is a group of three or more independently driven rollers, and partition doors are provided at at least two of the dividing points of the in-furnace conveyance roller. When changing the heat treatment conditions, an empty compartment is formed between the previously treated material and the subsequently treated material, so that the atmosphere and/or temperature in this chamber is changed to be suitable for the subsequently treated material. I can do it. Therefore, when changing heat treatment conditions due to changes in steel type, etc., subsequent treatment materials can be charged in sequence without leaving the entire furnace empty, which not only improves the operating rate of the furnace but also reduces the total fuel consumption. can be achieved.

For example, in a conventional roller hearth type heat treatment furnace, the furnace empty time was 10 to 15 Hr/time, but in the present invention,
3.58 r/time, and if the processing material is changed 10 times a month on average, R drive motor, M3... drive motor for charging, drive motor for extraction, R, -R1... compartment.

However, according to the present invention, the patent applicant Chugai Roko Kogyo Co., Ltd. agent
Patent attorney Aoyama Aoyama's full name is 720 hours/M.

[Brief explanation of drawings]

Fig. 1 is a schematic explanatory diagram of a roller hearth type heat treatment furnace according to the present invention, Fig. 2 shows a case in which a high-speed transport material is charged following a low-speed transport material, and Fig. 3 shows a low-speed transport material followed by a high-speed transport material. FIG. 4 is an explanatory diagram of each material to be transported, the time of clutch switching, and the operating state of a partition door when carrying out a charging process.

Claims (1)

[Claims] (1) The in-furnace conveyance roller is divided into three or more independently driven roller groups, and partition doors are provided at at least two of the dividing points of the in-furnace conveyance roller, so that when the heat treatment conditions are changed, the partition door A roller hearth type heat treatment furnace characterized in that it is possible to form an empty compartment between the last material of the preceding treatment material and the leading material of the subsequent treatment material by closing the furnace.