JP7381002B2 - heat treatment system - Google Patents

Description

The present invention relates to a heat treatment system that performs heat treatment such as heat treatment (heat treatment of metal), firing, and drying on objects to be heat treated such as metals, semiconductors, and ceramics.

Patent Document 1 discloses an invention in which an object to be heat-treated is slid in a heating furnace and heat-treated while being moved.

Japanese Patent Application Publication No. 2017-145996

Heat treatment conditions vary depending on the object to be heat treated, and the configuration of the heating furnace needs to be changed depending on the object to be heat treated.

An object of the present invention is to divide the heat treatment conditions into a plurality of steps in a heat treatment system for heat treating an object to be heat treated, and to realize the heat treatment function of each step using a plurality of general-purpose heating furnace units. As a result, regardless of changes in heat treatment conditions, it is possible to perform heat treatment on various objects to be heat treated by simply changing the operating method of each heating furnace unit without changing the general-purpose heating furnace unit configuration. There is a particular thing.

The heat treatment system of the first aspect of the present invention divides a series of heat treatments on an object to be heat treated into a plurality of heat treatment steps, and performs all of the heat treatment functions in each heat treatment step except for the cooling function of cooling the object to be heat treated. A plurality of general-purpose heating furnace units are provided, and the heating furnace units are arranged and connected to each other in correspondence with a plurality of heat treatment steps necessary for performing a series of heat treatments on a specific object to be heat treated. a control device configured to operate each of the heating furnace units to realize a heat treatment function corresponding to each heat treatment step, and to realize heat treatment for the specific object to be heat treated as a whole; The object to be heat treated is carried into the heating furnace unit corresponding to the heat treatment to be performed first, and the object to be heat treated is carried out from the heating furnace unit corresponding to the heat treatment to be performed last, corresponding to the heat treatment between the first and the last heat treatment. The heating furnace unit is provided with a conveyor that sequentially transports the object to be heat-treated from the heating furnace unit corresponding to the heat treatment to be performed first to the heating furnace unit corresponding to the heat treatment to be performed next, and the control device At the timing when each heat treatment in each heating furnace unit is completed, the transfer machine is controlled to carry out the heat-treated object for which heat treatment has been completed from the heating furnace unit, and the heat-treated object to be heat-treated is transferred to the heating furnace. Transport to the unit.

According to the first invention, a series of heat treatments for a specific object to be heat treated is divided into a plurality of heat treatment steps, and each general-purpose heating furnace unit arranged corresponding to each step is controlled by a control device. Operate to perform the necessary heat treatment. Further, the object to be heat treated is transported by a transport machine so that necessary heat treatment is performed in each heating furnace unit. Therefore, when the heat treatment conditions change for different objects to be heat treated, the heat treatment necessary for each heat treatment step can be performed simply by changing the control content for each heating furnace unit by the control device. Furthermore, by adding or deleting a heating furnace unit, it is possible to perform heat treatment on objects to be heat treated that have different heat treatment conditions that cannot be handled by changing the control contents by the control device alone. Therefore, by using a general-purpose heating furnace unit and changing the combination of heating furnace units or changing the control content by the control device, it is possible to heat-treat a plurality of types of objects to be heat-treated with different heat treatment conditions.

A second aspect of the present invention is that in the first aspect, a cooling unit is provided for cooling the object to be heat treated as one of the heat treatment functions necessary for performing a series of heat treatments on the object to be heat treated, and The cooling unit is arranged in correspondence with the heat treatment step of cooling the object to be heat treated among the heat treatment steps necessary for performing heat treatment on the object, and connected to the heating furnace unit.

According to the second invention, by providing the cooling unit, even if a heat treatment step for cooling the object to be heat treated is included in a series of heat treatments, it can be handled.

A third aspect of the present invention is based on the first aspect , wherein the heating furnace unit includes a sensor that detects the conveyance of the object to be heat treated to the heating furnace unit by the conveyor, and the control device includes: Among a plurality of heat treatment steps in which a series of heat treatments are performed, when the sensor detects that the object to be heat treated in the heating furnace unit corresponding to the next heat treatment step of the heat treatment step is carried out, the The conveyor is controlled so that the object to be heat treated in the heating furnace unit corresponding to the heat treatment step is carried out and carried into the heating furnace unit corresponding to the next heat treatment step as the next object to be heat treated.

A fourth aspect of the present invention is based on the second aspect , wherein the heating furnace unit or the cooling unit includes a sensor that detects the conveyance of the object to be heat-treated by the conveyor to the heating furnace unit or the cooling unit. The control device is configured to control the control device when the object to be heat treated in the heating furnace unit or the cooling unit corresponding to the heat treatment step next to the heat treatment step in a series of heat treatment steps is carried out. When detected by the sensor, the object to be heat treated in the heating furnace unit or the cooling unit corresponding to the heat treatment step is carried out and transferred to the heating furnace unit or the cooling unit corresponding to the next heat treatment step. The conveyance machine is controlled so as to carry in the heat-treated product.

According to the third and fourth inventions, the material to be heat treated is transported to the heating furnace unit or cooling unit arranged before and after the material to be heat treated is carried out from the heating furnace unit or cooling unit in the latter stage. , the next object to be heat treated is carried from the heating furnace unit or cooling unit to the subsequent heating furnace unit or cooling unit. Therefore, by adjusting in advance the timing of transporting the object to be heat-treated according to the heat treatment time of the object to be heat-treated for each heating furnace unit or cooling unit, it is possible to transfer the object from the heating furnace unit or cooling unit to the subsequent heating furnace unit or cooling unit. The heat-treated material can be continuously transported without being retained on the transport machine.

A fifth aspect of the present invention is that in any one of the first to fourth aspects, each of the heating furnace units is configured such that the time from when the object to be heat treated is carried into the heating furnace unit to when it is carried out is equal to each other. The heat treatment step, which takes a longer time than other methods, is divided into multiple units, and these multiple units are connected in series.

According to the fifth invention, the heat treatment time in each heating furnace unit is made equal to each other. Therefore, each heating furnace unit is capable of continuous operation, with the next object being carried in immediately after the object to be heat treated is carried out. Therefore, the productivity of the heat treatment system can be increased.

A sixth aspect of the present invention is that in the first or third aspect , the heating furnace unit is a short-time unit in which the heat treatment time from the time of carrying in the object to be heat treated to the time of taking it out is relatively short, and the heat treatment time is compared. and a long-time unit with a long target, the long-time units are arranged before and after the short-time unit, respectively, and the control device controls the short-time unit and the long-time unit to control the heat treatment target. The timing of conveyance of the long-time unit preceding the short-time unit is made earlier than that of the long-time unit subsequent to the short-time unit by the heat treatment time of the short-time unit.

A seventh aspect of the present invention is that in the second or fourth aspect , the heating furnace unit or the cooling unit is a short time unit that takes a relatively short heat treatment time from loading to unloading of the object to be heat treated; and a relatively long long-time unit, the long-time units are arranged before and after the short-time unit, and the control device controls the short-time unit and the long-time unit to control the heat treatment target. The timing at which the long time unit is transported is made earlier than the long time unit located before the short time unit by the heat treatment time of the short time unit compared to the long time unit located after the short time unit.

According to the sixth and seventh inventions, the former long-time unit transports the object to be heat-treated as quickly as the heat treatment time of the short-time unit, and the latter long-time unit completes the heat treatment, including the short-time unit. When the object to be heat-treated in the subsequent long-time unit is transported, the heat treatment of the object to be heat-processed is just completed in the short-time unit, and the object to be heat-processed can be transported without being wastefully accumulated between each unit. Therefore, productivity as a heat treatment system can be improved.

An eighth aspect of the present invention is that in the first or third aspect , the heating furnace unit includes a second short-time unit that takes a relatively short heat treatment time from loading to unloading of the object to be heat treated; a second long-time unit for which the heat treatment time is relatively long; the second long-time unit is formed by arranging the same second long-time units in parallel and connecting them to the second short-time unit; The timing at which the heat-treated objects are transported to each of the second long-term units arranged in parallel is shifted from each other, and the heat-treated objects transported to each of the second long-term units are arranged at different times. In the second short-time unit, the conveying machine is controlled so that the objects are conveyed sequentially with a time difference corresponding to the timing shift.

A ninth invention of the present invention is the second or fourth invention, wherein the heating furnace unit or the cooling unit is a second short-time unit that takes a relatively short heat treatment time from carrying in to carrying out the object to be heat treated; a second long-time unit for which the heat treatment time is relatively long; the second long-time unit is formed by arranging the same second long-time units in parallel and connecting them to the second short-time unit; The timing at which the heat-treated objects are transported to each of the second long-term units arranged in parallel is shifted from each other, and the heat-treated objects transported to each of the second long-term units are arranged at different times. In the second short-time unit, the conveying machine is controlled so that the objects are conveyed sequentially with a time difference corresponding to the timing shift.

In the eighth and ninth aspects of the invention, the short-time unit may be placed either on the front side or on the back side of the long-time units arranged in parallel. Alternatively, a configuration may be adopted in which they are arranged on both the front stage side and the rear stage side. Further, the number of rows of long-time units arranged in parallel can be determined according to the above-mentioned time difference between the long-time units and the short-time units. In that case, it is desirable that the number of rows is set so that the time during which the heat-treated material remains on the conveyor between each unit is shortened, regardless of the difference in heat treatment time between the long-time unit and the short-time unit.

According to the eighth and ninth inventions, the objects to be heat-treated are transported in parallel in the long-time unit, and in series in the short-time unit, so that the objects to be heat-treated are carried out from the long-time unit in the short-time unit. It is possible to eliminate the need to wait for the time difference required for heat treatment of both units. Therefore, it is possible to improve the productivity of heat treatment of the object to be heat treated in a system in which long-time units and short-time units coexist.

A tenth aspect of the present invention is that in any one of the first to ninth aspects, each of the heating furnace units includes a burner that heats the inside of the heating furnace containing the material to be heat treated by burning fuel, and an electric heater that generates heat. and a heater that heats the inside of the heating furnace containing the material to be heat-treated, and the control device operates at least the burner while heating the inside of the heating furnace of each heating furnace unit to the set temperature of each heat treatment step. select and operate the most suitable heat source from the burner, the heater, or a combination of the burner and the heater while raising the temperature of the object to be heat treated, and while maintaining the temperature of the object to be heat treated. , is controlled to operate at least the heater.

According to the tenth invention, the burner and the heater can be appropriately used depending on the required amount of thermal energy in each heating furnace unit and the request for a faster temperature increase rate. Therefore, as a whole, it is possible to save energy and shorten the heat treatment time while suppressing the environmental load.

An eleventh aspect of the present invention is the tenth aspect, wherein the control device is capable of changing the ratio of the operating time of the burner and the heater in each of the heating furnace units having the same configuration in a range of 0 to 100%, The heating furnace unit is used as a heating furnace for raising the temperature of the object to be heat treated by making the burner operate longer than the heater, and the heating It is possible to switch between using the furnace unit as a soaking furnace that maintains the temperature of the object to be heat treated.

According to the eleventh invention, by using the same heating furnace unit and changing the ratio of the operating time of the burner and the heater, it is possible to use the heating furnace and the soaking furnace properly.

A twelfth aspect of the present invention is that in any one of the first to ninth aspects, each of the heating furnace units is a hot air circulation furnace that forcedly circulates gas in the heating furnace, and the hot air circulation speed during forced circulation is The control device circulates the hot air at high speed while increasing the temperature of the object to be heat treated, and while maintaining the temperature of the object to be heat treated, and in the heating furnace. Before the material to be heat treated is brought in, the temperature in the heating furnace is raised to a set temperature and while the temperature is maintained, the hot air is controlled to circulate at a low speed.

A thirteenth invention of the present invention is that in any one of the first to ninth inventions, each of the heating furnace units is a hot air circulation furnace in which gas in the heating furnace is forcedly circulated, and the circulation speed of the hot air during forced circulation is When the heating furnace unit is a heating furnace that raises the temperature of the object to be heat treated, the control device circulates hot air at high speed to cover the heating furnace unit. When used as a soaking furnace to maintain the temperature of the heat-treated material, it is controlled to circulate hot air at a low speed.

According to the twelfth and thirteenth inventions, in the heat treatment step of raising the temperature of the object to be heat treated, hot air in the heating furnace is circulated at high speed to quickly raise the temperature. In addition, in the heat treatment step to maintain the temperature of the object to be heat treated, and in the heat treatment step to maintain the temperature in the heating furnace at the set temperature before carrying the object to be heat treated into the heating furnace, the hot air in the heating furnace is blown at a low speed. Circulate. Therefore, it is possible to eliminate unevenness in the temperature of the object to be heat-treated and to keep it uniform as a whole, and to suppress fluctuations in the temperature of the object to be heat-treated.

FIG. 1 is a block diagram showing a heat treatment system as a first embodiment of the present invention. FIG. 1 is a schematic perspective view of the first embodiment. FIG. 2 is a schematic plan view of the first embodiment. It is an enlarged perspective view of one heating furnace unit in a 1st embodiment. It is a schematic block diagram of the burner device in a heating furnace unit. It is a time chart for explaining the effect of the first embodiment. It is a flowchart which shows the content of conveyance machine control by the control apparatus of 1st Embodiment. FIG. 2 is an explanatory diagram showing how the temperature inside the heating furnace and the temperature of the object to be heat treated are controlled when the heating furnace unit is used as a solution heating furnace. FIG. 9 is an explanatory diagram similar to FIG. 8, showing a case where the heating furnace unit is used as a solution soaking furnace. It is an explanatory view similar to Drawing 8, and shows the time when a heating furnace unit is used as an age hardening temperature rising furnace. It is an explanatory view similar to Drawing 8, and shows the time when a heating furnace unit is used as an age hardening soaking furnace. It is a block diagram showing a heat treatment system as a second embodiment of the present invention. It is a time chart for explaining the effect of the second embodiment. It is a flowchart which shows a part of the content of conveyance machine control by the control apparatus of 2nd Embodiment. It is a flowchart which shows the remainder of the content of conveyance machine control by the control apparatus of 2nd Embodiment.

<Overall configuration of first embodiment>
1 to 3 show a first embodiment of the invention. The first embodiment is an example in which the present invention is applied to a heat treatment system that performs heat treatment on aluminum as an object to be heat treated. The heat treatment steps required to heat treat aluminum in such a heat treatment system can be divided into six steps as shown in Table 1.

In the first embodiment, as shown in FIG. 1, each divided heat treatment step is realized by heating furnace units 10A to 10G, a quenching water tank (sometimes referred to as a cooling unit) 20A, and a cooling unit 20B. The heating furnace units 10A to 10G, the quenching water tank 20A, and the cooling unit 20B are arranged in correspondence with each heat treatment step and connected to each other. Here, as shown in Table 1, the heat treatment time for the age hardening temperature raising step and the cooling step is 30 minutes, whereas the heat treatment time for the solution temperature raising step, the solution soaking step, and the age hardening soaking step is 30 minutes. is 1 hour each, so the solution temperature raising step, the solution soaking step, and the age hardening soaking step each consist of two heating furnace units as shown in FIG. This makes the heat treatment time of each heating furnace unit uniform.

Each of the heating furnace units 10A to 10G is a general-purpose heating furnace unit that is configured to perform any of the heat treatment functions of each heat treatment step. Each of the heating furnace units 10A to 10G includes a heating furnace 12 equipped with a burner device 11, as shown in FIG. As shown in FIGS. 2 and 3, each of the heating furnace units 10A to 10G is packaged in a hexahedral shape to facilitate connection when a plurality of them are combined and connected. Note that in FIGS. 2 and 3, illustration of the heating furnace 12 and burner device 11 in the heating furnace units 10A to 10G is omitted. Moreover, illustration of the water tank etc. in the quenching water tank 20A is omitted.

As shown in Table 1, in the heat treatment system of the first embodiment, aluminum is solution-treated and age-hardened. Therefore, as shown in Fig. 1, in the solution heating furnace (hereinafter also referred to as solution heating furnace 10A, 10B) consisting of heating furnace units 10A and 10B, the inside of the heating furnace is maintained at 510 degrees, and aluminum The temperature in the heating furnace is raised to 510 degrees over a total of 1 hour for 30 minutes each, and in the solution soaking furnace using heating furnace units 10C and 10D (hereinafter also referred to as solution soaking furnaces 10C and 10D), the temperature inside the heating furnace is raised to 510 degrees. for 30 minutes each, for a total of 1 hour. The next quenching water tank 20A has a water tank, and the aluminum to be heat treated is placed in the water tank and rapidly cooled to 70 degrees for quenching. The processing time here is 3 minutes.

In the next aging hardening heating furnace (hereinafter also referred to as age hardening heating furnace 10E) using the heating furnace unit 10E, the inside of the heating furnace is maintained at 220 degrees, and the aluminum is heated to 220 degrees over 30 minutes. In the age hardening soaking furnace (hereinafter also referred to as age hardening soaking furnace 10F and 10G) using the heating furnace units 10F and 10G, the inside of the heating furnace is maintained at 220 degrees for 30 minutes each, for a total of 1 hour. The next cooling unit 20B naturally cools the heat-treated aluminum to 30 degrees in the atmosphere. The processing time here is 30 minutes.

Each of the heating furnace units 10A to 10G is a general-purpose heating furnace unit 10 as described above and has the same structure, but in order to realize different heat treatment functions, each heating furnace is controlled by the control device 13 as shown in FIG. Burner devices 11 of units 10A to 10G are controlled. The details will be described later.

<Overall configuration of conveyor 30>
As shown in FIGS. 2 and 3, the heating furnace units 10A to 10G, the quenching water tank 20A, and the cooling unit 20B are configured such that the object to be heat treated passes through each unit 10A to 10G, 20A, and 20B by a conveyor 30. ing. The conveyor 30 is constituted by a roller conveyor (not shown), and carries the object to be heat-treated placed on the roller conveyor into the heating furnace 12 of the heating furnace units 10A to 10G, and carries it out. Further, the conveyor 30 immerses the heat-treated object placed on the roller conveyor into the quenching water tank 20A, and causes it to pass through the space of the cooling unit 20B. Here, the conveyor 30 includes the heating furnace units 10A to 10G, the quenching water tank 20A, and the cooling unit 20B so that the objects to be heat treated can be conveyed independently to each of the heating furnace units 10A to 10G, the quenching water tank 20A, and the cooling unit 20B. It is configured independently corresponding to the cooling unit 20B. The conveyor 30 is controlled by a control device 13 (see FIG. 1).

As shown in FIG. 1, a plurality of sensors 40 are provided on the side of the conveyor 30. In FIG. 1, each sensor 40 is shown as a filled triangle. The sensor 40 is provided at the entrance and exit of each unit 10A to 10G, 20A, and 20B. In addition, two sensors 40 are provided in each unit 10A to 10G and 20B so as to detect that the object to be heat treated is carried into each unit 10A to 10G and 20B except for the quenching water tank 20A. It is provided. Two sensors 40 are provided in each unit 10A to 10G and 20B, and are arranged to detect the front and rear ends of the object to be heat treated that has been carried into each unit 10A to 10G and 20B. . Furthermore, two sensors 40 are provided on the exit side of the cooling unit 20B so as to detect when the heat treatment of the object to be heat treated is completed and the object is taken out from the cooling unit 20B. A detection signal from each sensor 40 is sent to the control device 13. Each sensor 40 can be configured by a known proximity sensor.

<Control of conveyor 30>
The conveyance machine 30 carries out the heat-treated object from the cooling unit 20B when the cooling process of the cooling unit 20B, which is the final processing step of the heat treatment, is completed. When the sensor 40 detects that the object to be heat treated has been carried out from the cooling unit 20B, the control device 13 carries out the object to be heat treated from the age hardening soaking furnace 10G in the previous stage, and The conveyance machine 30 is operated to carry it into the cooling unit 20B. The control device 13 includes a digital computer.

FIG. 7 shows the details of control of the transport machine 30 by the control device 13. The control details of the conveyor 30 for the cooling unit 20B and the aging hardening soaking furnace 10G described above are shown in steps S1 to S3. Thereafter, the control device 13 similarly operates the conveyor 30 (see steps S4 to S24), and when the heat treatment in the solution heating furnace 10A, which performs the first heat treatment on the object to be heat treated, is completed, The object to be heat treated is carried out from the solution heating furnace 10A, and then the object to be heat treated to start heat treatment is carried into the solution heating furnace 10A. This control corresponds to the processing in steps S25 and S26 in FIG. In FIG. 7, illustrations are omitted between steps S4 and S5 and between steps S22 and S23 because the same processing as before is performed sequentially.

In the first embodiment, the heat treatment time of each unit 10A to 10G, 20B (corresponding to the long-time unit of the present invention) except the quenching water tank 20A is 30 minutes, whereas the heat treatment time of the quenching water tank 20A (corresponding to the The heat treatment time (corresponding to a time unit) is 3 minutes. However, if the objects to be heat-treated are simply conveyed sequentially as described above, the conveyor machines 30 corresponding to each unit 10A to 10G, 20A, and 20B will transport the objects to be heat-treated from the previous unit to the subsequent unit every 30 minutes. I will do it. Therefore, after the heat-treated material that has been cooled for 3 minutes is carried out from the quenching water tank 20A, it is kept on the conveyor 30 for 27 minutes (30 minutes - 3 minutes) until it is carried into the next stage age hardening temperature raising furnace 10E. You will have to wait.

In order to avoid this inefficiency, in the first embodiment, the transport of the heat-treated materials from the quenching water tank 20A to the cooling unit 20B, which are located later than the quenching water tank 20A, is transferred to the solution transporting material which is located earlier than the quenching water tank 20A. The time is shifted by 3 minutes and the process is carried out earlier than the transfer of the heat-treated objects from the warm furnace 10A to the solution soaking furnace 10D. FIG. 6 is a time chart showing the timing of conveyance of the heat-treated object by the conveyor 30 corresponding to each unit 10A to 10G, 20A, and 20B. At time T1 in FIG. 6, the objects to be heat-treated are transferred from the quenching water tank 20A to the cooling unit 20B, and heat-treated by the age-hardening heating furnace 10E to the age-hardening soaking furnace 10G. The control after this T1 corresponds to the processing in step S27 and steps S1 to S6 in FIG.

At time T2, 27 minutes later, the object to be heat treated is transferred from the solution heating furnace 10A to the solution soaking furnace 10D, which were undergoing heat treatment three minutes before T1. At this time point T2, the heat-treated material taken out from the solution soaking furnace 10D is carried into the quenching water tank 20A, and the quenching process is performed. The control after T2 corresponds to the processing in steps S21 to S26 in FIG.

Three minutes later, at time T3, the quenching process of the object to be heat treated in the quenching water tank 20A is completed, so the object to be heat treated is transferred from the quenching water tank 20A to the cooling unit 20B. At the time of T3, the heat treatment of the object to be heat treated in the age hardening heating furnace 10E to the cooling unit 20B has been completed after 30 minutes. The control after T3 corresponds to the processing in step S27 and steps S1 to S6 in FIG. Thereafter, as shown in FIG. 6, each time point T3, T4, and T5 corresponds to each time point T1, T2, and T3 described above, and the same operation is repeated.

As a result, according to the first embodiment, from when a single heat-treated object is carried into the solution heating furnace 10A corresponding to the first heat treatment step until it is carried out from the cooling unit 20B corresponding to the last heat treatment step. The heat treatment time for one cycle is 4 hours and 3 minutes (30 minutes x 8 steps + 3 minutes). This means that if the objects to be heat treated were simply conveyed in 30-minute cycles under the conventional concept, it would take 4 hours and 30 minutes (30 minutes x 9 steps), but the productivity was only 27 minutes per cycle. can be increased. However, in this case, the time for the object to be heat-treated to move between each unit was set to zero.

<Specific configuration of carrier 30>
As shown in FIGS. 2 and 3, in the case of the heat treatment system of the first embodiment, the object to be heat treated is conveyed by a conveyor 30 as indicated by an arrow. That is, the object to be heat treated is carried into the heating furnace unit 10A from a conveyor 30 connected to the heating furnace unit 10A, and the carried object passes through the heating furnace units 10B to 10D and the quenching water tank 20A, and is then quenched. It is carried out from the water tank 20A. During this time, the aluminum to be heat treated is solutionized and hardened.

The heat-treated material carried out from the quenching water tank 20A is carried into the heating furnace unit 10E from a conveyor 30 connected to the heating furnace unit 10E, and further passes through the heating furnace units 10F, 10G, and the cooling unit 20B, and then passes through the cooling unit 10E. It is carried out from 20B. During this time, the aluminum to be heat treated is age hardened. In this embodiment, the transport machine 30 connected to the quenching water tank 20A and the transport machine 30 connected to the heating furnace unit 10E are separated from each other. Transferred by. Both transport machines 30 may be configured to form a series of transport machines connected to each other. In that case, there is no need for a robot hand or the like to transfer the object to be heat treated.

<Configuration of heating furnace unit 10>
As shown in FIG. 5, the burner device 11 of each heating furnace unit 10A to 10G includes a burner 11a and a heater 11b. The burner 11a is configured to be supplied with liquefied natural gas (corresponding to the fuel of the present invention, hereinafter simply referred to as gas) and air, and combust the gas to generate a flame in the heating furnace 12. Furthermore, the heater 11b is configured to circulate the combustion gas in the heating furnace 12, heat the circulating gas with Joule heat from the electric heater, and return it as heated gas into the heating furnace 12.

The heating furnace 12 is a well-known hot air circulation furnace, and although not shown, the heating furnace 12 is equipped with a blower that forcibly circulates gas within the heating furnace. The operation of the blower is controlled by a control device 13, and the circulation speed of the hot air of the gas to be circulated can be changed to two levels: high and low. Specifically, the control device 13 increases the circulation speed of hot air when increasing the temperature of the object to be heat treated in the solution heating furnaces 10A and 10B and the age hardening heating furnace 10E. Further, in the solution soaking furnaces 10C and 10D and the age hardening soaking furnaces 10F and 10G, when maintaining the temperature of the object to be heat treated, the hot air circulation speed is set to be low. Furthermore, in each of the heating furnace units 10A to 10G, when maintaining the temperature inside the heating furnace at the set temperature before carrying the object to be heated into the heating furnace, the hot air circulation speed is set to be low. Note that the speed of the blower may be changed in multiple steps rather than in two steps, and the speed can be finely controlled depending on the situation of each heating furnace unit 10A to 10G. In this way, by controlling the circulation speed of the hot air in the heating furnace 12, the temperature can be raised quickly. Furthermore, it is possible to eliminate unevenness in the temperature of the object to be heat-treated and to keep it uniform as a whole, and to suppress fluctuations in the temperature of the object to be heat-treated.

<Actions and effects of the first embodiment>
8 to 11 show the heating furnace unit 10 in a solution heating furnace (Fig. 8), a solution soaking furnace (Fig. 9), an age hardening heating furnace (Fig. 10), and an age hardening soaking furnace (Fig. 11). This figure shows how the temperature inside the heating furnace 12 and the object to be heat treated are controlled when used as a heating furnace. Note that the illustrated content is merely an example, and the optimum heat source is selected according to the required temperature setting and heating rate.

As shown in FIG. 8, when the heating furnace unit 10 is used as the solution heating furnaces 10A and 10B, gas and air are supplied to the burner 11a of the heating furnace 12, and the flame generated by the burner 11a causes the As shown by Ta, the inside of the heating furnace 12 is raised to the set temperature of 510° C. (furnace temperature increase). Even after the inside of the heating furnace 12 reaches the set temperature, the supply of gas and air to the burner 11a is continued to maintain the inside of the heating furnace 12 at the set temperature. During this time, each time the objects 1 to 3 are carried into the solution heating furnaces 10A and 10B, the objects 1 to 3 are rapidly heated to the set temperature, as shown by Tb in FIG. Here, both when raising the temperature inside the heating furnace 12 and when maintaining it at the set temperature, it is heated by the burner 11a which uses gas as a heat source, but the required thermal energy is higher than that in the latter case when maintaining the temperature. Since the former is larger, the amount of gas and air supplied to the burner 11a is larger in the former than in the latter. Although FIG. 8 shows that the objects 1 to 3 to be heat-treated are heated all at once, in the first embodiment, as described above, the objects to be heat-treated are heated in a solution heating furnace. This work is divided between 10A and 10B.

As shown in FIG. 9, when the heating furnace unit 10 is used as a solution soaking furnace 10C, 10D, gas and air are supplied to the burner 11a of the heating furnace 12, and as shown by Ta in FIG. The inside of the furnace 12 is raised to the set temperature of 510° C. (furnace temperature increase). After the inside of the heating furnace 12 reaches the set temperature, the operation of the burner 11a is stopped and the heater 11b is activated to maintain the inside of the heating furnace 12 at the set temperature. During this period, each time the objects 1 to 3 are carried into the solution soaking furnaces 10C and 10D, the objects 1 to 3 are maintained at a set temperature, as shown by Tb in FIG. When raising the temperature inside the heating furnace 12, it is heated by the burner 11a (gas), but when maintaining the inside of the heating furnace 12 at a set temperature, only the heater 11b of the heating furnace 12 is operated. This is because the heat-treated objects brought into the solution soaking furnaces 10C and 10D are already heated to the set temperature when they are brought in, so less heat energy is required to maintain the heat-treated objects at the set temperature. It's for a reason. Heating by the heater 11b does not require exhaust from the heating furnace 12, so it does not adversely affect the environment and contributes to energy saving.

As shown in FIG. 10, when using the heating furnace unit 10 as an age hardening temperature raising furnace 10E, gas and air are supplied to the burner 11a of the heating furnace 12, and as shown by Ta in FIG. Raise the temperature inside the furnace to the set temperature of 220°C (furnace temperature increase). During the temperature rise, the amount of gas and air supplied to the burner 11a is suppressed and the heater 11b is activated. That is, heating by gas and heating by electricity are performed in combination. Although it is possible to heat only with gas, using electricity in combination can reduce the negative impact on the environment and contribute to energy savings. After the temperature inside the heating furnace 12 reaches the set temperature, the operation of the burner 11a is stopped and the inside of the heating furnace 12 is maintained at the set temperature only by the heater 11b. During this period, each time the objects 1 to 3 to be heat treated are carried into the age hardening temperature raising furnace 10E, the objects 1 to 3 to be heat treated are rapidly heated to a set temperature, as shown by Tb in FIG. 10. When raising the temperature inside the heating furnace 12, heating is performed by the burner 11a (gas), but when maintaining the inside of the heating furnace 12 at a set temperature, only the heater 11b of the heating furnace 12 is operated. This is because the temperature of the object to be heat treated heated in the age hardening temperature rising furnace 10E is relatively low at 220°C compared to when it is used as the solution heating temperature rising furnaces 10A and 10B in FIG. This is because less energy is required. Of course, when maintaining the inside of the heating furnace 12 at a set temperature, it is possible to use not only the operation of the heater 11b but also heating with gas as necessary.

As shown in FIG. 11, when the heating furnace unit 10 is used as an age hardening soaking furnace 10F, 10G, gas and air are supplied to the burner 11a of the heating furnace 12, and as shown by Ta in FIG. The temperature inside the furnace 12 is raised to the set temperature of 220° C. (furnace temperature increase). During the temperature rise, the amount of gas and air supplied to the burner 11a is suppressed and the heater 11b is activated. That is, heating by gas and heating by electricity are performed in combination. Although it is possible to heat only with gas, using electricity in combination can reduce the negative impact on the environment and contribute to energy savings. After the temperature inside the heating furnace 12 reaches the set temperature, the operation of the burner 11a is stopped and the inside of the heating furnace 12 is maintained at the set temperature only by the heater 11b. During that time, each time the heat-treated objects 1 to 3 are carried into the age-hardening soaking furnaces 10F and 10G, the heat-treated objects 1 to 3 are maintained at a set temperature, as shown by Tb in FIG. 11. When raising the temperature inside the heating furnace 12, heating is performed by the burner 11a (gas), but when maintaining the inside of the heating furnace 12 at a set temperature, only the heater 11b of the heating furnace 12 is operated. This is because the heat-treated objects carried into the age-hardening soaking furnaces 10F and 10G have already been heated to the set temperature when they are brought in, and the temperature of the heat-treating objects heated in the age-hardening soaking furnaces 10F and 10G is This is because the temperature is relatively lower at 220° C. than when used as the solution heating furnaces 10A and 10B in FIG. 8, so that less thermal energy is required for heating. The burner devices 11 of each of the heating furnace units 10A to 10G are controlled by a control device 13.

If the shape, type, etc. of the object to be heat treated changes and it becomes necessary to change the heat treatment conditions, the control details for each heating furnace unit 10A to 10G are changed to match the changed heat treatment conditions. The heating characteristics in units 10A to 10G are changed. Moreover, the cooling characteristics in each quenching water tank 20A and cooling unit 20B are changed as necessary. This change can accommodate changes in heat treatment conditions, and there is no need to change each of the heating furnace units 10A to 10G, quenching water tank 20A, and cooling unit 20B, or change their arrangement.

For example, in order to increase the temperature increase in the solution heating furnaces 10A, 10B and the age hardening heating furnace 10E, the amount of gas and air to the burner 11a is increased to increase the amount of heat generated by the burner 11a. On the other hand, if the temperature rise is to be lowered, the amount of gas and air supplied to the burner 11a is reduced to reduce the amount of heat generated by the burner 11a. Moreover, when the maintenance temperature in the solution soaking furnaces 10C and 10D and the age hardening soaking furnaces 10F and 10G is made higher, the current to the heater 11b is increased to increase the amount of heat generated by the heater 11b. On the other hand, if the maintenance temperature is to be lowered, the amount of heat generated by the heater 11b is reduced by reducing the current flowing to the heater 11b.

Furthermore, when the solution heating furnace 10B is changed to a solution soaking furnace, this can be realized by changing the operation control of the burner 11a and the heater 11b from the contents shown in FIG. 8 to those shown in FIG. Moreover, when changing the age-hardening soaking furnace 10F to an age-hardening temperature rising furnace, it can be realized by changing the operation control of the burner 11a and the heater 11b from the content shown in FIG. 11 to the content shown in FIG. 10. In this way, by adjusting the ratio (0 to 100%) of the operating time of the burner 11a and the operating time of the heater 11b, as well as each output, the same heating furnace unit 10 can be used as a heating furnace, soaking furnace, etc. as appropriate. be able to.

Furthermore, if the heat treatment conditions are changed such that the number of heat treatment steps is increased or decreased, a new heating furnace unit 10, quenching water tank 20A is required for each heating furnace unit 10A to 10G, quenching water tank 20A, and cooling unit 20B. Alternatively, this can be addressed by adding the cooling unit 20B or removing any one of the heating furnace units 10A to 10G, the quenching water tank 20A, and the cooling unit 20B.

As described above, in the first embodiment, a series of heat treatments for a specific object to be heat treated is divided into a plurality of heat treatment steps, and corresponding to each step, each of the general-purpose heating furnace units 10A to 10G and the quenching water tank 20A are and a cooling unit 20B. Each of the heating furnace units 10A to 10G is operated by the control device 13 so that the heat treatment necessary for each heat treatment step is performed. Further, the object to be heat treated is transported by a transporter 30 so that the necessary heat treatment is performed in each of the heating furnace units 10A to 10G, the quenching water tank 20A, and the cooling unit 20B. Therefore, when the object to be heat treated changes and the heat treatment conditions change, it is possible to perform the heat treatment necessary for each step by simply changing the control content of each heating furnace unit 10A to 10G by the control device 13. Therefore, the heating furnace units 10A to 10G can commonly use the general-purpose heating furnace unit 10. That is, by simply changing the control content by the control device 13 using the general-purpose heating furnace unit 10, it is possible to heat-treat a plurality of types of objects to be heat-treated with different heat-treating conditions.

<Configuration, operation, and effects of the second embodiment>
FIG. 12 shows a second embodiment of the invention. The feature of the second embodiment over the first embodiment is that each heating furnace unit 10A1 to 10D1 corresponding to each heating furnace unit 10A to 10D in the first embodiment (in the second long-time unit of the present invention) The difference is that the heat treatment time for (equivalent) was changed from 30 minutes each to 60 minutes each. Further, the solution heating furnace 10B in the first embodiment is replaced with the solution soaking furnace 10B1. Furthermore, as the heat treatment time is changed as described above, heating furnace units 10A2 to 10D2 (corresponding to the second long-time unit of the present invention) having the same configuration are arranged in parallel to each heating furnace unit 10A1 to 10D1. This is the point. The other configurations of the second embodiment are the same as those of the first embodiment, and the same parts will not be explained again.

In the second embodiment, the conveyor 30 is configured to convey the heat-treated object to each of the heating furnace units 10A1 to 10D1, 10E to 10G, the quenching water tank 20A, and the cooling unit 20B. Further, a conveying machine 30A similar to the conveying machine 30 is also provided for the heating furnace units 10A2 to 10D2. The carrier 30A is connected to the carrier 30 so as to join together at the quenching water tank 20A. The transport of the object to be heat treated by the transport machine 30A is controlled to be carried out 30 minutes later than the transport by the transport machine 30.

FIG. 13 is a time chart showing the timing of conveyance of the heat-treated object by the conveyance machines 30 and 30A corresponding to each unit 10A1 to 10D1, 10A2 to 10D2, 20A, 10E to 10G, and 20B. At time T1 in FIG. 13, the material to be heat treated is transferred from the quenching water tank 20A to the cooling unit 20B (corresponding to the second short-time unit of the present invention), and from the age hardening temperature rising furnace 10E to the age hardening soaking unit. Heat treatment of the object to be heat treated is performed by the furnace 10G.

14 and 15 show details of control of the transport machines 30 and 30A by the control device 13. The control details of the conveyor 30 for the above-mentioned quenching water tank 20A to cooling unit 20B are shown in steps S1 to S6. This control content is the same as in the first embodiment.

At time T2, 27 minutes later, the object to be heat treated is transferred from the solution heating furnace 10A1 to the solution soaking furnace 10D1, which were undergoing heat treatment three minutes before T1. At this time point T2, the object to be heat treated, which has been taken out from the solution soaking furnace 10D1, is carried into the quenching water tank 20A, and the quenching process is performed thereon. This control corresponds to the processing in steps S7 to S36 in FIG. This control content corresponds to steps S7 to S26 of the first embodiment shown in FIG. 7, but in the case of the second embodiment, the processes after step S31 are performed as in steps S8 and S9 of FIG. A flag F is set to remember that this has occurred.

Three minutes later, at time T3, the quenching process of the object to be heat treated in the quenching water tank 20A is completed, so the object to be heat treated is transferred from the quenching water tank 20A to the cooling unit 20B. At the time of T3, the heat treatment of the object to be heat treated in the age hardening heating furnace 10E to the cooling unit 20B has been completed after 30 minutes. This control corresponds to the processing in step S37 and steps S1 to S6 in FIG. This control content corresponds to step S27 and steps S1 to S6 of the first embodiment shown in FIG.

At time T4, the material to be heat treated is transferred from the solution heating furnace 10A2 to the solution soaking furnace 10D2. At this point, the object to be heat-treated that has been taken out of the solution soaking furnace 10D2 is carried into the quenching water tank 20A, and the quenching process is performed thereon. This control corresponds to the processing in steps S41 to S46 in FIG. 15. At time T3, the process of step S7 is executed, and at step S8, the flag F is set to "F=1", so at time T4, the process proceeds from step S8 to step S41. Become. Thereafter, each time point T5, T6, T7, and T8 corresponds to each time point T1, T2, T3, and T4 described above, and the same operation is repeated.

As a result, according to the second embodiment, the heat treatment time of the solution heating furnace 10A1 to the solution soaking furnace 10D1 is 60 minutes, and the heat treatment time of the age hardening temperature raising furnace 10E to the cooling unit 20B is 30 minutes, Even though the conveyance speed is different between the front and back of the conveyor 30, heat treatment can be performed without wastefully accumulating the object to be heat treated. That is, the solution heating furnace 10A1 to the solution soaking furnace 10D1 are arranged in parallel with the solution heating furnace 10A2 to the solution soaking furnace 10D2 having the same configuration as the solution heating furnace 10A1. - Solution soaking furnace 10D1 and solution heating furnace 10A2 - Highly productive heat treatment is realized by shifting the timing of conveying the heat-treated material in the solution soaking furnace 10D2 by 30 minutes.

<Other embodiments>
Although specific embodiments have been described above, the present invention is not limited to their appearance and configuration, and various changes, additions, and deletions are possible. For example, in the above embodiment, a heat treatment system was described in which the object to be heat treated is aluminum and heat treatment is performed on the metal. It may also be applied to a heat treatment system.

In the embodiment described above, the burner 11a and the heater 11b are provided together in one burner device 11, but they may be provided independently from each other in the heating furnace 12.

10, 10A to 10G, 10A1 to 10D1, 10A2 to 10D2 Heating furnace unit 11 Burner device 11a Burner 11b Heater 12 Heating furnace 13 Control device 20A Quenching water tank (cooling unit)
20B Cooling unit 30, 30A Conveyor 40 Sensor

Claims (13)

A general-purpose heating furnace unit is used that divides a series of heat treatments on objects to be heat-treated into multiple heat treatment steps, and is configured to perform all of the heat treatment functions in each heat treatment step , except for the cooling function that cools the objects to be heat-treated. Provide multiple
The heating furnace units are arranged and connected to each other in correspondence with a plurality of heat treatment steps necessary for performing a series of heat treatments on a specific object to be heat treated,
a control device that operates each of the heating furnace units so as to realize a heat treatment function according to each heat treatment step, and realizes heat treatment of the specific object to be heat treated as a whole;
The object to be heat treated is carried into the heating furnace unit corresponding to the heat treatment to be performed first among the heating furnace units, and the object to be heat treated is carried out from the heating furnace unit corresponding to the heat treatment to be performed last. For the heating furnace unit corresponding to the heat treatment performed between, a conveying machine sequentially transports the object to be heat treated from the heating furnace unit corresponding to the heat treatment to be performed first to the heating furnace unit corresponding to the heat treatment to be performed next. Equipped with and
The control device controls the conveyance machine at the timing when each heat treatment in each heating furnace unit is completed, and carries out the heat-treated object for which the heat treatment has been completed from the heating furnace unit, and transfers the heat-treated object to be heat-treated from now on. A heat treatment system carried into the heating furnace unit. In claim 1,
As one of the heat treatment functions necessary to perform a series of heat treatments on the heat-treated object, it is equipped with a cooling unit that cools the heat-treated object.
A heat treatment system, wherein the cooling unit is arranged in a manner corresponding to a heat treatment step of cooling the object to be heat treated among the heat treatment steps necessary for performing heat treatment on the specific object to be heat treated and connected to the heating furnace unit. In claim 1 ,
The heating furnace unit includes a sensor that detects the conveyance of the object to be heat treated to the heating furnace unit by the conveyor,
The control device detects, by the sensor, that the object to be heat treated in the heating furnace unit corresponding to the heat treatment step next to the heat treatment step in a series of heat treatment steps is carried out. Then, the material to be heat treated in the heating furnace unit corresponding to the heat treatment step is taken out and carried into the heating furnace unit corresponding to the next heat treatment step as the next material to be heat treated. Heat treatment system that controls the machine. In claim 2 ,
The heating furnace unit or the cooling unit includes a sensor that detects the conveyance of the object to be heat-treated by the conveyor to the heating furnace unit or the cooling unit,
The control device is configured to control the control device when the object to be heat treated in the heating furnace unit or the cooling unit corresponding to the heat treatment step next to the heat treatment step in a series of heat treatment steps is carried out. When detected by the sensor, the object to be heat treated in the heating furnace unit or the cooling unit corresponding to the heat treatment step is carried out and transferred to the heating furnace unit or the cooling unit corresponding to the next heat treatment step. A heat treatment system that controls the conveyor to transport the heat treated material. In any one of claims 1 to 4 ,
Each of the heating furnace units is configured by dividing the heat treatment step, which takes a longer time than other units, into a plurality of units so that the time from the time the object to be heat treated is carried into the unit to the time it is carried out is equal to each other, A heat treatment system consists of multiple units connected in series. In claim 1 or 3 ,
The heating furnace unit includes a short-time unit for which the heat treatment time from loading to unloading the object to be heat treated is relatively short, and a long-time unit for which the heat treatment time is relatively long, and The long-duration units are respectively arranged at the rear stage,
The control device controls the timing at which the heat-treated object is transported to the short-time unit and the long-time unit, and the long-time unit that is earlier than the short-time unit is configured to control the long-time unit that is subsequent to the short-time unit. A heat treatment system that speeds up the heat treatment time of the unit by the heat treatment time of the short time unit. In claim 2 or 4 ,
The heating furnace unit or the cooling unit includes a short-time unit that takes a relatively short heat treatment time from loading to unloading of the object to be heat treated, and a long-time unit that takes a relatively long heat treatment time, and is a stage preceding the short time unit. and the long-duration unit is arranged at the rear stage, respectively,
The control device controls the timing at which the heat-treated object is transported to the short-time unit and the long-time unit, and the long-time unit that is earlier than the short-time unit is configured to control the long-time unit that is subsequent to the short-time unit. A heat treatment system that speeds up the heat treatment time of the unit by the heat treatment time of the short time unit. In claim 1 or 3 ,
The heating furnace unit includes a second short-time unit for which the heat treatment time from loading to unloading of the object to be heat-treated is relatively short, and a second long-time unit for which the heat treatment time is relatively long, and the second The long-time unit is formed by arranging the same second long-time units in parallel and connecting them to the second short-time unit,
The control device is configured to mutually shift timings at which the objects to be heat treated are conveyed to each of the second long-term units arranged in parallel, and to shift the timing at which the objects to be heat-treated are conveyed to each of the second long-term units arranged in parallel. A heat treatment system in which the conveyance machine is controlled so that the heat-treated material is conveyed sequentially in the second short-time unit with a time difference corresponding to the timing shift. In claim 2 or 4 ,
The heating furnace unit or the cooling unit includes a second short time unit whose heat treatment time from carrying in to carrying out the heat treatment object is relatively short, and a second long time unit whose heat treatment time is relatively long, The two long-time units are formed by arranging the same second long-time units in parallel and connecting them to the second short-time unit,
The control device is configured to mutually shift timings at which the objects to be heat treated are conveyed to each of the second long-term units arranged in parallel, and to shift the timing at which the objects to be heat-treated are conveyed to each of the second long-term units arranged in parallel. A heat treatment system in which the conveyance machine is controlled so that the heat-treated material is conveyed sequentially in the second short-time unit with a time difference corresponding to the timing shift. In any one of claims 1 to 9 ,
Each of the heating furnace units includes a burner that heats the inside of the heating furnace containing the object to be heat treated by burning fuel, and a heater that heats the inside of the heating furnace including the object to be heat treated by heat generated by an electric heater,
The control device operates at least the burner while raising the temperature inside the heating furnace of each heating furnace unit to the set temperature of each heat treatment step, and operates the burner or the above while raising the temperature of the object to be heat treated. A heat treatment system in which an optimal heat source is selected and operated from a heater or a combination of the burner and the heater, and at least the heater is operated while maintaining the temperature of the object to be heat treated. In claim 10 ,
The control device is capable of changing the ratio of the operating time of the burner and the heater in the respective heating furnace units having the same configuration in a range of 0 to 100%, and by making the operating time of the burner longer than that of the heater. The heating furnace unit is used as a heating furnace to raise the temperature of the object to be heat treated, and the heating furnace unit is used as a soaking furnace to maintain the temperature of the object to be heat treated by increasing the operating time of the heater longer than the burner. A heat treatment system that can be switched between being used as a furnace. In any one of claims 1 to 9 ,
Each of the heating furnace units is a hot air circulation furnace that forcedly circulates gas in the heating furnace, and the circulation speed of the hot air during forced circulation can be changed to at least two levels, high and low,
The control device circulates hot air at high speed while increasing the temperature of the heat-treated material, and while maintaining the temperature of the heat-treated material, and before carrying the heat-treated material into the heating furnace. The heat treatment system is controlled to circulate hot air at a low speed while raising and maintaining the temperature of the heat treatment system. In any of claims 1 to 9 ,
Each of the heating furnace units is a hot air circulation furnace that forcedly circulates gas in the heating furnace, and the circulation speed of the hot air during forced circulation can be changed to at least two levels, high and low,
When the heating furnace unit is a heating furnace that raises the temperature of the object to be heat treated, the control device circulates hot air at high speed, and the heating furnace unit is a soaking furnace that maintains the temperature of the object to be heat treated. When the heat treatment system is controlled to circulate hot air at low speed.

Images