JP2009228116A - Continuous tempering furnace - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a continuous tempering furnace with which the throughput thereof can be obtained as the same degree as the throughput in a quenching process and further, the setting space is made to be small and the energy saving can be attained. <P>SOLUTION: Conveyors for carrying material A to be treated from charging hole 24 to a discharging hole 26 in the furnace body 2, are arranged in the plurality of steps at the upper and the lower parts, and the length in the longitudinal direction of the furnace body 2 is made to be short. The charging holes, the discharging holes and doors, are independently arranged at each of the plurality of steps of conveyors, and stirring fans for convectively heating the materials to be treated, are provided with one by one in each prescribed interval along the carrying direction for materials to be treated. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a continuous tempering furnace for tempering a workpiece to be tempered while being continuously conveyed.

Conventionally, with regard to steel mechanical parts such as rolling ring bearing rings and gears, toughness is imparted by tempering a workpiece as a workpiece hardened by quenching by a tempering furnace. .
As one of the tempering furnaces, there is used a continuous tempering furnace that tempers while continuously conveying an object to be processed in a horizontal direction by a conveyor (see, for example, Patent Document 1). When tempering the object to be treated, a continuous tempering furnace may be arranged continuously to the quenching furnace, and a quenching process and a tempering process may be performed in series.

JP-A-1-74256

In order to perform the quenching process and the tempering process in series, it is necessary to make the processing capacity of the continuous tempering furnace equal to the processing capacity of the quenching process. However, since the heating time required for tempering is longer than the heating time required for quenching the object to be treated, tempering with a long heating time is achieved if the conveyor speed of each process is made the same to equalize the processing capacity. The furnace length of the furnace becomes longer. For this reason, in addition to requiring a large installation space, there is a problem that the area of the furnace wall becomes wide, the amount of heat dissipated from the furnace wall increases, and the energy cost increases.
The present invention has been made in view of the above problems, and an object of the present invention is to provide a continuous tempering furnace capable of reducing the installation space and saving energy.

  The continuous tempering furnace according to the present invention for achieving the above object includes an inlet for charging a workpiece to be quenched into the furnace, an outlet for discharging the workpiece to be processed in the furnace, and the inlet. A furnace body having a door that opens and closes the discharge port and a heating means for heating the inside of the furnace, and a conveyor that conveys the workpiece from the inlet to the discharge port of the furnace body, and is quenched. A continuous tempering furnace for tempering the object to be processed, wherein the conveyor is provided in a plurality of stages.

  According to the continuous tempering furnace having the above-described configuration, the object to be processed can be distributed and conveyed to a plurality of upper and lower conveyors, so that the throughput of the object to be processed is ensured even if the conveying speed of the conveyor is reduced. be able to. For this reason, while being able to shorten the full length of a continuous tempering furnace, the area of a furnace wall can decrease correspondingly and the heat loss from a furnace wall can be suppressed. Therefore, the installation space can be reduced and energy saving can be achieved.

  In the continuous tempering furnace, it is preferable that an inlet, an outlet and a door of the furnace body are provided independently for each of a plurality of stages of conveyors. In this case, since only the inlet and outlet necessary for charging and discharging the workpiece can be opened and closed, the heat in the furnace leaks outside through the inlet and outlet when the workpiece is charged and discharged. Can be suppressed. For this reason, energy saving can be achieved more effectively.

  In the continuous tempering furnace, the furnace body is provided with one agitating fan at a predetermined interval along the conveyance direction of the object to be processed, by which the object to be processed conveyed by each conveyor is convectively heated. Is preferred. In this case, the workpieces conveyed by multiple conveyors can be convectively heated with a single stirring fan, greatly reducing the number of stirring fans compared to conventional continuous continuous tempering furnaces. can do. For this reason, the structure of the continuous tempering furnace can be simplified and the cost can be reduced.

  According to the continuous tempering furnace according to the present invention, the overall length can be shortened, so that the installation space can be reduced and the heat loss from the furnace wall can be suppressed to save energy.

  FIG. 1 is a schematic sectional view showing an embodiment of a continuous tempering furnace according to the present invention, and FIG. 2 is a sectional view taken along line XX in FIG. This continuous tempering furnace is used for tempering a steel workpiece A such as a bearing ring, a furnace body 2 that is supported by a gantry 1 and includes an electric heater 3 as a heating means, and a workpiece. The upper and lower conveyors 4 for transporting A are provided.

  The furnace body 2 has a rectangular parallelepiped shape in which the furnace interior 21 is surrounded by a heat insulating wall, and the length in the longitudinal direction (left-right direction in FIG. 1) is approximately the length in the longitudinal direction of the conventional furnace body. It is set to 1/2. The one end wall 23 of the furnace body 2 is provided with an insertion port 24 for introducing a plurality of workpieces A stacked in the basket 6 into the furnace 21. Is provided with a discharge port 26 for discharging the workpiece A put into the furnace 21. The input port 24 and the discharge port 26 are provided in two upper and lower stages corresponding to the upper conveyor 4 and the lower conveyor 4, respectively.

  A pair of upper and lower first doors 27 are provided outside the one end wall 23 to open and close two upper and lower input ports 24, and two upper and lower discharge ports are provided outside the other end wall 25. A pair of upper and lower second doors 28 for opening and closing the doors 26 are provided. The pair of first doors 27 can be opened and closed individually by being driven up and down by the pair of first fluid pressure cylinders C1. The pair of second doors 28 can be individually opened and closed by being driven up and down by the pair of second fluid pressure cylinders C2.

  A plurality of the electric heaters 3 are arranged along the conveying direction of the conveyor 4 on both side surfaces of the furnace body 2. The electric heater 3 can heat the atmosphere in the furnace 21 to the tempering temperature and maintain the temperature.

  On the ceiling of the furnace body 2, a stirring fan 5 is provided for convectively heating the workpiece A conveyed by the upper and lower conveyors 4. One agitation fan 5 is provided at predetermined intervals along the conveyance direction of the workpiece A. That is, the stirring fan 5 for convectively heating the upper object A and the agitating fan for convectively heating the lower object A are combined into one stirring fan 5. For this reason, compared with the conventional long continuous tempering furnace, the number of stirring fans can be reduced significantly. As a result, the structure of the continuous tempering furnace can be simplified and the cost can be reduced.

  The upper and lower two-stage conveyor 4 is a roller hearth type in which a large number of rollers 4 a that are rotationally driven are arranged in parallel, and is provided in a range from the inlet 24 to the outlet 26 of the furnace body 2. The rollers 4a of the upper conveyor 4 and the rollers 4a of the lower conveyor 4 are driven at the same rotational speed by a driving means (not shown).

  The conveying speed of the conveyor 4 is set according to the length in the longitudinal direction of the furnace body 2 so as to ensure the time necessary for tempering the workpiece A. In this embodiment, since the length in the longitudinal direction of the furnace body 2 is set to approximately ½ of the length of the conventional furnace body, the conveying speed of the conveyor 4 is set to be the same as that in the conventional continuous tempering furnace. The time required for tempering the workpiece A is secured by setting it to approximately ½ of the conveying speed of the conveyor.

When the workpieces A are sequentially discharged from the quenching furnace while being accommodated in the basket 6, the upper conveyor 4 and the lower conveyor 4 are passed through a pair of upper and lower loading ports 24 by a loading device (not shown). Are alternately distributed and conveyed.
In this way, the workpiece A is distributed and transported to the upper and lower conveyors 4, so that the workpiece A is transported at a speed half that of the conventional transport speed. The processing amount of the processed material A can be ensured. For this reason, the to-be-processed object A which has been quenched and sequentially supplied can be continuously tempered without being retained.

In the continuous tempering furnace, the length in the longitudinal direction of the furnace body 2 is set to approximately ½ of the length in the longitudinal direction in the conventional furnace body, so that the installation space can be reduced, The amount of heat dissipated from the furnace wall can be reduced, and energy saving can be achieved accordingly.
Further, since the inlet 24, the outlet 26 and the first and second doors 27 and 28 are provided independently for each of the upper and lower two-stage conveyors 4, they are necessary for the input and discharge of the workpiece A. Only the inlet 24 and the outlet 26 can be opened and closed. For this reason, it is possible to prevent the heat in the furnace 2 from leaking outside the furnace through the inlet 24 and the outlet 26 when the workpiece A is charged and discharged. As a result, energy saving can be achieved more effectively.

  The continuous tempering furnace according to the present invention is not limited to the above embodiment. For example, in the above embodiment, the conveyor 4 is provided in two upper and lower stages, but it may be provided in a plurality of stages of three or more. In this case, the length of the furnace body 2 in the longitudinal direction is set to the conveyor. It can be further shortened according to the number of stages of four. Further, as a heating means for the furnace 21, a burner system can be adopted instead of the electric heater 3.

It is a schematic sectional drawing which shows one Embodiment of the continuous tempering furnace which concerns on this invention. It is the XX sectional view taken on the line of FIG.

Explanation of symbols

2 Furnace body 21 Furnace 24 Input port 25 Discharge port 27 First door 28 Second door 3 Electric heater (heating means)
4 Conveyor 5 Stirring fan A Workpiece

Claims (3)

An inlet for introducing the workpiece to be quenched into the furnace, an outlet for discharging the article to be treated which has been introduced into the furnace, a door for opening and closing the inlet and the outlet, and heating for heating the interior of the furnace A furnace body having means;
A conveyor that conveys the workpiece from the inlet of the furnace body toward the outlet,
A continuous tempering furnace for tempering the quenched workpiece;
A continuous tempering furnace, wherein the conveyor is provided in a plurality of upper and lower stages.   The continuous tempering furnace according to claim 1, wherein the inlet, outlet, and door of the furnace body are provided independently for each of the plurality of stages of conveyors.   2. The continuous tempering according to claim 1, wherein the furnace body includes one agitation fan at a predetermined interval along a conveyance direction of the workpieces for convectively heating the workpieces conveyed by the conveyors. Furnace.

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