JPS6067628A - Continuous heating furnace - Google Patents

Abstract

PURPOSE:To provide the titled furnace capable of applying heat treatment to a large number of kinds and small amount of articles to be treated with good efficiency without wastefulness, by demarcating a plurality of heating chambers by partitioning an upper part into a plurality of zones by drop arches, and constituting a lower part so as to convey articles to be heat treated by an air pervious type conveyor. CONSTITUTION:In a continuous heat treatment furnace constituted by providing a cooler 6 to a continuous heating furnace 1, the upper part of the above mentioned heating furnace 1 is partitioned into a plurality of zones by drop arches 9 and burners 7 and a thermocouple thermometers 8 are provided at every zone to constitute substantially individual temp. controllable heating chambers 2, 3, 4, 5. On the other hand, in the cooler 6, cooling air is sent to articles to be heat treated on an air pervious type conveyor 15 from a blower 16 through a duct 19 and an air nozzle 18 and the supply of quenching water mist is enabled while the suppression of heat dissipation is enabled by an insulating cover 17. By the above mentioned constitution, the heating condition and the cooling speed in heat treatment are controlled to perform the continuous heat treatment of an article to be heat treated with good efficiency.

Description

Detailed Description of the Invention ■3 Background of the Invention Industrial Application Field The present invention is directed to heating and cooling 7j for improving the quality of metal materials.
The present invention relates to a heat treatment furnace that continuously performs heat treatment operations.

All high-grade castings used for prior art automobile parts and machine parts are -C.
It is necessary to undergo heat treatment to improve the structure. Heat treatment is a heating and cooling operation performed for the purpose of imparting desired properties to a metal material, and includes quenching for the purpose of hardening the gold B material and quenching for the purpose of softening and stabilizing the structure. Examples include normalizing for the purpose of making the structure finer and more uniform.

This heat treatment is carried out using a heat treatment furnace that is appropriately combined with a heating furnace, soaking furnace, cooling means, slow cooling means, etc. according to the purpose of material improvement. However, this heat treatment furnace has different heat treatment operations depending on the type of product to be treated, mowing, and improvement purpose, so it is common to use a batch type for general-purpose use when only a small amount of products are to be treated. , it is dedicated as a continuous type only when it is human and has continuity. Therefore, there has been no conventional heat treatment furnace that can efficiently and efficiently use a wide variety of treated stones for multiple purposes, that is, a continuous multipurpose heat treatment furnace.

1. Purpose of the Invention The object of the present invention is to provide a heat treatment furnace that can be used efficiently and for multiple purposes without wasting waste even when a small amount of different types of materials are to be treated.

■9 Structure of the Invention Characteristic Structure of the Invention In order to achieve the above object, the continuous heat treatment furnace of the present invention has the following features:
(a) The upper part of the drop arch is partitioned into a plurality of zones, and each zone is equipped with a heating source that can independently control the humidity, so that it is essentially defined into a plurality of heating chambers, while the inside of each heating chamber is divided into a plurality of zones. a continuous heating furnace equipped with a speed-controllable ventilation conveyor that passes through and conveys the heat-treated product at an arbitrary speed;
(b) At the outlet of the continuous heating furnace, a speed-controllable ventilated carry-out conveyor is provided to carry out the heat-treated articles at a constant speed, and a J5 is placed under the conveyor to increase the cooling capacity. An air nozzle that spouts cooling air arbitrarily toward the heat-treated product; a water nozzle that sprays A-tamist in a duct that supplies cooling air to the air nozzle when further increasing the cooling capacity; and a water nozzle that sprays A-tamist when increasing the cooling rate. and a heat-insulating cover for covering the heat-treated products on the carry-out conveyor and controlling heat dissipation, and a cooling section.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The structure of the present invention will be explained in detail below based on one embodiment shown in the drawings.

FIG. 1 shows an embodiment of the continuous pretreatment ljl furnace according to the present invention in a schematic central longitudinal sectional view. This continuous heat treatment furnace mainly includes a continuous heating furnace 1 that heats a heat-treated product (hereinafter referred to as a work) W to a predetermined humidity and soaks it, and a cooling section 6 that cools the work W at a desired speed.

The continuous heating furnace 1 is partitioned upward into a plurality of zones by a Dorotsch arch 9, and each zone is provided with a heating source 7 that can largely independently control humidity, so that the continuous heating furnace 1 is substantially divided into a plurality of heating chambers 2, 3, 4.
．． 5. That is, in the case of the continuous heating furnace 1 of this embodiment, which is implemented as a normalizing furnace, there is a heating chamber 2 for heating the workpiece W to a predetermined humidity, and a scorching chamber for heating the workpiece W to make the temperature distribution uniform. 3 and a primary slow cooling chamber 4 and a second slow cooling chamber 5, which are mainly used to gradually cool the work W from a high temperature to a predetermined humidity, are successively connected in a communicating state. Further, in the case of this embodiment, a preheating chamber 11 for preheating the workpiece W using the combustion gas discharged from the heating chamber 2 is provided immediately in front of the heating chamber 2 to recover exhaust heat.

The heating chamber 2. Soaking room 3. Each of the primary slow cooling chamber 4 and the second slow cooling chamber 5 has a heating burner 7 and a thermocouple thirst trace meter 8.
It is a room designed to maintain a desired temperature by being equipped with each room, and is named differently depending on its purpose. For example, when used for hardening treatment, the above-mentioned primary annealing chamber 4 and second annealing chamber 5 are used as soaking chambers. Heating chamber 2. Soaking room 3. The upper part of each of the primary slow cooling chamber 4 and the second slow cooling room 5 is partitioned off by a hanging wall (drop arch) 9 and is independent to enable the ICmC system. The transport lines L for passing the workpieces W are opened at the top and communicated with each other.

Therefore, the combustion gas in each chamber 2, 3, 4, 5 passes through each hanging wall 9, sequentially moves to the adjacent chamber near the workpiece loading port 33, and is discharged from the ff31i12 connected to the preheating chamber 11 into the hot air. Ru. The combustion gas flowing into the preheating chamber 11 from the heating chamber 2 side is transferred to the heat exchanger 1 piped inside the preheating chamber 11.
After heating the combustion air of each burner 7 via the burner 7 and directly warming the workpiece W to be carried in to preheat it, the transfer line 1. , t! f:
It is extracted from the 3u port 14.

The continuous heat treatment furnace 1 includes a preheating chamber 11. Heating chamber 2, soaking chamber 3. In order to continuously carry in and out the work W into each of the primary slow cooling chamber 4 and the second slow cooling chamber 5, an endless work conveying means 101fi is provided. In this embodiment, a ventilated mesh belt conveyor 10 is used as the workpiece conveyance means 10 in order to convey the workpieces W of various shapes and brush cuttings without interfering with the flow of combustion gas. This mesh belt conveyor 10 includes a pulley 23 immediately before the preheating chamber 1 and a pulley 2 in the second slow cooling chamber 5.
4 so as to pass through the heating furnace, and the workpiece W is provided to pass through the furnace at a desired speed, that is, a predetermined processing time, by the operation of a variable speed drive motor (not shown). There is.

On the other hand, an open cold NI section 6 for cooling the work W at a predetermined speed is connected to the outlet 22 of the second slow cooling chamber 5. The cooling unit 6 includes a ventilation type mesh belt conveyor 15 whose speed can be controlled, a blower device 16 that blows cooling air onto the workpiece W from below, and a heat insulation cover 17 that suppresses radiation of radiant heat from the workpiece W. It consists of Senba II! 1f
Reference numeral 18 indicates a nozzle 18 which is located below the mesh belt conveyor 15 and forms several serpentine air streams perpendicular to the mesh belt conveyor 15 which injects air and is connected to the nozzle 18 to supply air. It consists of an air duct 19, a spray nozzle 20 installed in the duct 19 to spray water into the supplied air, and a damper 21 to adjust the amount of supplied air. Adjustment of the cooling speed in the cooling unit 6 is achieved by changing the speed of the mesh belt 1 to the conveyor 15, adjusting the ventilation VC unit 16 to change the amount of cooling air supplied, and This is done by adding moisture to the air.

For example, if you want to obtain a hardening effect by increasing the cooling rate,
Increase the speed of mesh belt conveyor 15 and work Wl.
While improving the flow of cooling uI air by preventing fi from overlapping, the damper 21 is activated to blow a large amount of cooling air from the nozzle 18. In the case of rapid cooling for the purpose of hardening, it is sufficient to set the amount of Jl commensurate with the shape and wall thickness of the workpiece W, but if the workpiece is thick enough to be insufficiently cooled, water should be injected from the spray nozzle 20. The latent heat of vaporization of water is used to increase the cooling effect.On the other hand, if the cooling rate is to be similar to suppress quenching, At the same time as restricting the air flow, the speed of the mesh belt conveyor 15 is reduced or intermittent feeding is performed to overlap the wires W on the conveyor 15 to prevent heat dissipation. The workpiece unloading port 22, which is the outlet of the secondary slow cooling chamber 5, is covered with a heat retaining cover 17 to suppress radiation of radiant heat from the workpiece W.

The heat retaining cover 17 is a cover having a U-shaped cross section and lined with a heat insulating material such as ceramic fiber, and is provided so as to be movable along the mesh belt conveyor 15.

In addition, in the second slow cooling chamber 5 which is the exit side of the furnace, there is an exit side stream where the work W is taken out to the cold film 1 part 6 through the outlet 25 and the chute 26 of the mesh belt conveyor 10. In order to form channels 27 and 28 and cause a backflow of the atmosphere, side holes 29 and 30 connected to the vacuum source 31 are bored near the openings of the outlet channels 27 and 28 to draw air near the frontage. It is set up so that it can be sucked out at all times. That is, the outside air entering from the workpiece carry-out port 22 and the conveyor exit 25 is sucked out of the furnace from the side holes 29 and 30, together with a portion of the waste in the furnace, and further intrusion is prevented.

As the vacuum source 31, in the case of this embodiment, a suction feeding JIT machine (IDE) that is resistant to high temperatures is used, but it is not limited to this, and a vacuum pump or the like may be used. Also good. Further, it is preferable to incorporate an adjustment damper (not shown) into the collective duct 32 connecting the side holes 29 and 30 and the vacuum source 31 to balance the pressure.

The heat treatment furnace configured in this manner can apply desired heat treatment to objects to be heated of various shapes and sizes as described below. For example, the workpiece W, which has been preheated while passing through the preheating chamber 11, is heated to a predetermined temperature in the heating chamber 2,
After maintaining this state for a predetermined time in the soaking chamber 3, it is gradually cooled down to a predetermined temperature in the first annealing chamber 4 and the second annealing chamber 5. Annealing can be performed by covering the material and blowing cooling air (preliminarily performing slow cooling in the air). At this time, heating chamber 2. Soaking room 3. The primary slow cooling chamber 4 and the second slow cooling chamber 5 are each set to a predetermined temperature by controlling a burner 7. Further, the heating time is controlled by adjusting the speed of the mesh belt conveyor 10. In addition, the cooling rate is controlled by not actively applying cooling air and preventing heat dissipation, as described above, and by controlling the mesh belt 1-conveyor 15.
This is done by adjusting the speed of the

In addition, in the case of normalizing, the first annealing chamber 4 and the second annealing chamber 5 described above are used as soaking chambers, and the A
After heating to an appropriate temperature above point C3 or point ACm, take it out to the cooling section 6 and blow cooling air. Cool gently in air without IV.

In addition, in the case of quenching, heat to an appropriate humidity above the transformation point in heating chamber 2, then soak in soaking chambers 3, 4 and 5 for a predetermined period of time, and then transfer to cooling chamber 71, part 6. After taking it out, it is rapidly cooled under a blower of cooling air. here,
The cooling rate is controlled by adjusting the flow rate of the cooling air, by including a tamist in the cooling air, and by increasing the speed of the mesh belt conveyor 15 by 1. In the case of a workpiece W with uniform thickness, a sufficient blast cooling effect can be obtained by setting the air volume commensurate with its shape and wall thickness, but in the case of a thick workpiece W that tends to be insufficiently cooled, For this purpose, water mist must be sprayed from the spray nozzle 20 to provide cold NIL/N.

Each of the above heat treatment operations can be performed continuously without interruption if necessary. That is, while the heating operation in the continuous heating furnace 1 can be arbitrarily set by independent temperature control for each zone, the cold IJI operation can be performed by cutting off the cooling air, adjusting the wind ventilation, spraying A-tamist, or operating the heat insulation cover 17. Since it is a means that can be continuously adjusted such as , the next different heat treatment operation can be started even while the previous heat treatment operation is in progress.

As is clear from the above explanation, the continuous heat treatment furnace of the present invention! (a) The furnace is partitioned upwardly into a plurality of zones by a drop arch, and each zone is equipped with a heating source that can independently control the temperature, so that it is substantially divided into a plurality of heating chambers. a continuous heating furnace equipped with a speed-controllable ventilation conveyor that conveys the heat-treated products at an arbitrary speed; (b) conveys the heat-treated products at an arbitrary speed at the outlet of the continuous heating furnace; On the other hand, when increasing the cooling capacity below this conveyor, the direction toward the heat-treated products on the conveyor is increased.
an air nozzle that sprays cooling air arbitrarily at the air nozzle; a water nozzle that sprays water mist in the duct that supplies cooling air to the air nozzle when further increasing the cooling capacity; It consists of a cooling section equipped with a heat insulating cover that covers the products to be heat-treated and controls heat dissipation, and controls the set humidity of multiple heating zones in accordance with the specific heat-treated products, while adjusting the air pressure of the cooling air. Furthermore, since the cooling rate can be changed continuously depending on the product to be heat-treated by spraying the A-tamist or preventing heat dissipation by using a heat insulating cover, it is possible to continuously heat-treat a small number of products of high quality. That is, it is possible to efficiently heat-process a wide variety of products in small quantities without waste. In addition, the heating operation inside the continuous heating furnace can be set arbitrarily by independent temperature control for each zone, while the cooling operation can be performed by shutting off the cold lip wind,
iJl fB, m Since it is a continuously adjustable means such as spraying water mist or operating a heat insulation cover, it is possible to adjust the loading and loading intervals of the workpieces that are continuously transported by the mesh belt conveyor to the normal setting. By allowing a slightly different switching time, the next different heat treatment operation can be started even while the previous heat treatment operation is in progress.

[Brief explanation of the drawing]

FIG. 1 is a schematic central sectional view showing an embodiment of a continuous heat treatment furnace according to the present invention, and FIG. 2 is a plan view of a cold lJ1 section of the same heat treatment furnace. 1... Continuous processing furnace 27.2, 3.4.5... Heating chamber, 6... Cooling section, 7... Burner, 9... Drop arch, 10... Ventilation type conveyor (Mesh conveyor), 15... Oil layer type discharge conveyor (Mesh conveyor), 16... Air blower, 17... Moisturizing cover,
18..." annozzle, 19... duct, 20...
Water nozzle, 21...I11 mountain adjustment damper. Patent applicant Nippon F7-NES Industries Co., Ltd.

Claims (1)

[Claims] (a) The upper part is partitioned into a plurality of zones by a drop arch, and each zone is equipped with a heating source that can independently control its dehydration, effectively forming a plurality of heating chambers. a continuous heating furnace equipped with a speed-controllable ventilation conveyor that conveys the heat-treated product at an arbitrary speed C;
(b) At the exit of the continuous heating furnace, a general-purpose unloading conveyor is installed that can be controlled at any speed to unload the heat-treated products at an arbitrary speed. An air nozzle that spouts cooling air arbitrarily toward the heat-treated product, and a duct that supplies cooling air to the air nozzle to further increase cooling performance. 1. A continuous heat treatment furnace comprising a cooling section having a heat insulating cover that covers the heat-treated products on the discharge conveyor and controls heat dissipation when the cooling speed is brought close to that of the continuous heat treatment furnace.