JP2603305Y2 - Heat treatment equipment - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat treatment apparatus capable of sequentially carrying workpieces conveyed continuously into a required number of heat treatment furnaces and individually performing heat treatment.

[0002]

2. Description of the Related Art A heat treatment apparatus for heat-treating a continuously conveyed work is roughly classified into a heat treatment apparatus in which a work is continuously carried into a tunnel-type heat treatment furnace having both open ends and heated while passing at a constant speed. (See Japanese Unexamined Patent Publication (Kokai) No. 61-84321), a plurality of works are successively carried into a closed box-type heat treatment furnace, the doors are closed, and after a certain period of time, the work is sequentially carried out by opening the doors. (See JP-A-61-76873).

[0003] The former continuous heat treatment apparatus is excellent in performing continuous heat treatment under the same heat treatment conditions, but when a workpiece having different heat treatment conditions is continuously conveyed, it is required to be operated each time. Since the furnace temperature must be adjusted by shutting down the line, production efficiency is significantly reduced.The latter means that even if workpieces with different heat treatment conditions are continuously conveyed, Can be individually performed without stopping the heat treatment.

[0004] In the heat treatment, not only the work is heated, but also, for example, quenching performed for the purpose of obtaining the maximum hardness of the metal material is performed by immersing the work heated to a predetermined temperature in water or oil and rapidly cooling the work. There must be. In order to cope with such quenching, a cooling device is required. In the case of a tunnel-type heat treatment furnace, quenching can be performed continuously by providing one cooling device at the outlet.

[0005]

However, in high-mix low-volume production, for example, different types of cast workpieces are conveyed on the same production line. The third work may be different from each other, such as low-temperature quenching, and the third work may be annealed. Therefore, in a tunnel-type heat treatment furnace, heat treatment cannot be performed according to heat treatment conditions of each work.

On the other hand, in a case where a plurality of closed box-type heat treatment furnaces are arranged side by side, if it is attempted to provide a cooling liquid tank at the outlet of the heat treatment furnace, the cooling liquid tank and the cooling liquid are provided for every heat treatment furnace. Ancillary equipment such as a transfer device for dropping a work into the tank must be provided, and there is a problem that equipment costs increase.
Also, if the cooling liquid tank is installed in one place to reduce the equipment cost, and if the heated work is transported to the cooling liquid tank and tried to cool, the work will gradually cool down during the transportation, When the condition of the cooling rate is severe, there is a problem that an appropriate quenching process cannot be performed.

Further, if the cast work is quenched and the sand of the mold accumulates at the bottom of the tank, the sand adheres to the surface of the work during cooling. had been in water pumping at the same time sand pumped as, pump tends to malfunction inhaling sand,
Each time, parts have to be replaced, which raises a problem that maintenance costs increase.

Therefore, the present invention provides an arbitrary heat treatment including a cooling operation such as quenching as well as a heat treatment such as annealing and normalizing, according to the heat treatment conditions of individual workpieces which are continuously conveyed. At the same time, it is not necessary to provide a cooling facility in each of the plurality of heat treatment furnaces, which saves equipment costs, and allows the work to be immersed in the cooling liquid tank in a short time and at the same time accumulates in the cooling liquid tank. The technical task is to make it easy to discharge sand.

[0009]

In order to solve this problem, the present invention provides a closed box type heat treatment furnace in which temperature conditions can be set individually, with the work loading / unloading ports facing the front, and each heat treatment furnace being arranged in a line. An elevator device that lifts and lowers a lift equipped with a work loading / unloading mechanism for loading and unloading a work into and out of the furnace is disposed movably along the heat treatment furnace, and immerses a high-temperature work carried out of the heat treatment furnace onto the lift. coolant tank for is movably formed on the lowered position of the lift, the said cooling liquid tank, sediment outlet for timely discharge sand collected in the bottom of the tank falling from the workpiece together with the cooling liquid are formed It is characterized by the following.

[0010]

Since the temperature of the heat treatment furnace can be set individually, when a workpiece having different heat treatment conditions is conveyed, the temperature can be set to an arbitrary temperature according to the heat treatment conditions. The quenching temperature and tempering temperature can be arbitrarily set according to the heat treatment conditions, such as the temperature (for example, about 550 ° C) or the predetermined tempering temperature (for example, about 200 ° C).

Next, the continuously transported work is placed on a lift, and is first carried into a heat treatment furnace set at a quenching temperature, where quenching and heating are performed. In the state where the elevator device is moved to the position and the coolant tank is moved to the lowering position of the lift, the heated work is carried out onto the lift, and the lift is lowered into the coolant tank to remove the work. quenched, during which moves the lift and coolant tank before the heat treatment furnace set at tempering temperature, carrying in and tempering process the workpiece to a heat treatment furnace is raised to lift at the end of cooling. Therefore,
One set of the cooling liquid tank and the elevator device is sufficient, so that equipment costs can be saved, and at the same time, the work can be immersed in the cooling liquid tank in a short time by lowering the lift on the spot.

Furthermore, when the cast work is quenched, even if the sand of the mold remaining on the surface of the work falls into the cooling liquid tank and accumulates at the bottom of the tank, the sand discharge port is opened. Because the sand is discharged together with the coolant into the waste liquid collection pit formed on the floor, for example, the pump is not broken by sucking the sand, and the coolant can be easily replaced. By doing so, sand does not adhere to the surface of the work during cooling.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be specifically described based on embodiments shown in the drawings. 1 is a front view showing the device of the present invention, FIG. 2 is a side view thereof, and FIG. 3 is a perspective view showing a main part thereof.

The heat treatment apparatus comprises heaters 1a and 2a, respectively.
Are provided, and the temperature conditions can be individually set according to the heat treatment conditions of the work.
Are arranged side by side on the left and right sides with the work transfer path interposed therebetween. For example, the heat treatment furnace 1
And 2 are provided with a work transfer device 3 for carrying in and out, and a cooling liquid tank 4 for rapidly cooling a heated work at the time of quenching.

The work transfer device 3 includes the heat treatment furnaces 1 and 2
A lift 7 having a work loading / unloading mechanism 8 for taking in and out a work, and an elevator device 6 for moving the lift 7 up and down. The elevator device 6 is laid along the front of each of the heat treatment furnaces 1 and 2. It is arranged movably on the rail 9.

The elevator device 6 comprises a lifting device 11 mounted on a frame 10 which also serves as a guide rail for guiding the lift 7, and the lifting device 11 is hung in parallel with sprockets 13U and 13D arranged vertically. An endless chain 14 and a motor 15 for rotating and driving the upper sprocket 13U.
4 is connected to a slider 7b of the lift 7. In addition,
14a is a balance weight for offsetting the weight of the lift 7.

The lift 7 has a pedestal 7a on which the cage C is placed.
And the frame 1 attached to the upper end of the pedestal 7a.
And a slider 7b running up and down along 0.
The pedestal 7a is formed to have a cross section smaller than that of the cooling liquid tank 4,
While the cage C is mounted, the lift 7 can be immersed in the cooling liquid tank 4 together with the lift 7, and the upper end of the cage C immersed in the cooling liquid tank 4 is formed at a height not immersed in the cooling liquid tank 4. Have been.

The work loading / unloading mechanism 8 includes a sprocket 19 for moving a chain 17 having a loading / unloading dog 16 formed at the tip thereof along a lift 7, a frame 10, and a guide 18 formed in the heat treatment furnaces 1 and 2. Drive motor 20
The heat treatment furnaces 1 and 2 arranged on the left and right sides of the work transfer path are arranged on the left and right sides of the elevator device 6 so that the work can be carried in and out. The drive motor 20 transports the work so that the work does not submerge even when the work is immersed in the cooling liquid tank 4 by lowering the lift 7.
It is attached to the frame 10 of the feeding device 3.

The cooling liquid tank 4 is provided so as to be movable along a rail 21 laid inside the rail 9 for guiding the frame 10 so that the cooling liquid tank 4 can be located directly below the lift 7. Further, the cooling liquid tank 4 is formed as a two-tank type, for example, by connecting a high-temperature tank 4a with a water temperature of 80 ° C. and a low-temperature tank 4b with a water temperature of 40 ° C. to the left and right. Alternatively, one of the low-temperature tanks 4 b is positioned directly below the lift 7.

In each of the high-temperature tank 4a and the low-temperature tank 4b, sand that has fallen from the work and accumulated at the bottom of the tank when cooling the cast work is discharged to the waste liquid collecting pit 22 formed on the floor together with the cooling liquid in a timely manner. A sand discharge port 23 is formed, and each tank bottom is formed in a hopper shape inclined toward the sand discharge port 23. The sand discharged to the waste liquid collecting pit 22 flows into the precipitation tank 24 together with the cooling liquid, and is separated into sand and a cooling liquid by using a separating device (not shown) such as a scraping conveyor or a filter. The cooling liquid is recirculated to the cooling liquid tank 4 after being regenerated and used as a mold.

Reference numeral 25 denotes a sand discharging device for discharging sand dropped into the heat treatment furnace 1 from a cast workpiece.
A trolley 26 running along the bottom of the heat treatment furnace 1 is provided with a vacuum device 27, and its suction port 28 is formed so as to expand and contract toward a discharge port 29 formed at the bottom of the heat treatment furnace 1. Is extended and engaged with the discharge port 29, the opening / closing door 30 of the discharge port 29 is opened, and the sand is sucked.

The above is an example of the configuration of the present invention, and its operation will now be described. First, the temperatures of the heat treatment furnaces 1 and 2 are set according to the heat treatment conditions of the work. For example,
Hardening temperature 550 ° C, cooling temperature 80 ° C, tempering temperature 200 ° C
Cage C containing a workpiece to be quenched at a quenching temperature of 500 ° C., cooling temperature of 40 ° C., and a tempering temperature of 250 ° C. is transported at a ratio of 3: 1. In this case, for example, the heat treatment furnaces 1 and 2 facing each other across the transfer path are made into one set, and the heat treatment furnace 1 is set to 550 ° C.
Is set to 200 ° C., and for the two sets of heat treatment furnaces Y on the left side, the heat treatment furnace 1 is set to 500 ° C. and the heat treatment furnace 2 is set to 250 ° C.

Then, the elevator device 6 is moved to a work loading / unloading position (not shown), and the cage C is placed on the lift 7 positioned at the height of the work loading / unloading port 5 of the heat treatment furnaces 1 and 2. The elevator device 6 is moved to the front of the desired heat treatment furnace 1 according to the heat treatment conditions for the work in the cage C.

At this time, since the lift 7 is positioned at the height of the heat treatment furnace 1, the door of the work loading / unloading port 5 is opened at the same height, the work loading / unloading mechanism 8 is activated, and the chain 17 is moved. Then, the cage C is pushed into the heat treatment furnace 1. Next, the chain 17 is pulled out of the furnace 1 while leaving the cage C in the heat treatment furnace 1, the door of the work loading / unloading port 5 is closed, and the loading operation is completed. Each time the cage C is transported, it is sequentially carried into the heat treatment furnace 1 set at a temperature according to the heat treatment conditions.

Next, according to the end time of the quenching heating,
While positioning the frame 10 in front of the heat treatment furnace 1,
The cooling liquid tank 4 is located directly below the lift 7. At this time,
When cooling the work heated in the heat treatment furnace X, the high temperature bath 4a is positioned directly below the lift 7, and when cooling the work heated in the heat treatment furnace Y, the low temperature bath 4b is
Position it so that it is directly below.

When the quenching heating is completed, the door of the work loading / unloading port 5 is opened, and the chain 17 of the loading / unloading mechanism 8 is opened.
Is extended into the heat treatment furnace 1, the tip dog 16 is hooked on the cage C and pulled out onto the lift 7, and at the same time, the lift 7 is lowered to the lower end position by the elevator device 6,
The work in the cage C placed on the lift 7 is immersed in the cooling liquid tank 4. If a holding mechanism for fixing the cage C on the lift 7 is provided, the lift 7 can be lowered at a speed faster than the free fall, and the cooling liquid tank can be more quickly moved.
4 can be immersed in the work.

Next, when the cooling operation is completed, the lift 7 is raised to the height of the heat treatment furnace 2 and the cage C is loaded into the heat treatment furnace 2 to perform a tempering process. After the tempering heating for a predetermined time, the elevator device 6 is positioned in front of the heat treatment furnace 2 in accordance with the end time, and the lift 7 is positioned at the height of the work loading / unloading port 5 of the heat treatment furnace 2. The cage C is unloaded onto the lift 7, transferred to the work loading / unloading position, the cage C is lowered from the lift 7, and sent to the next step.

Also, when the cast work is quenched, the mold sand remaining on the surface of the work falls into the cooling liquid tank 4 when it is rapidly cooled in the cooling liquid tank 4 and is discharged when the sand collects to some extent. When the sand port 23 is opened, the sand in the tank is discharged to the waste liquid collecting pit 22 by the water pressure accompanying the outflow of the cooling liquid, so that no pump or the like for discharging the sand out of the tank is required. Then, after the sand and the cooling liquid are separated in the precipitation tank 24, the sand is regenerated and used as a raw material for a mold, and the cooling liquid is supplied again to the cooling liquid tank 4.

In the above embodiment, the quenching temperature and the cooling temperature are set by setting the right six heat treatment furnaces X and the left two heat treatment furnaces Y to different temperatures in accordance with the heat treatment conditions of the workpiece. Although only the case where two types of heat treatments having different temperatures and tempering temperatures are performed has been described, since the temperature of the heat treatment furnaces 1 and 2 can be individually controlled, the temperature is not limited to the two types but may be set according to any heat treatment conditions. Can be set.

For example, when performing annealing, normalizing, etc., the heating rate, holding temperature, holding time, cooling rate, etc. of the heat treatment furnaces 1 and 2 are set in advance, and heat treatment according to the heat treatment conditions of the work is performed. After the workpiece is carried into the furnace 1 or 2 and subjected to the heat treatment, the workpiece may be sent to the next step without being immersed in the cooling liquid tank 4. Heat treatment furnaces 1 and 2
Is described on both the left and right sides of the workpiece transfer path, but the present invention is not limited to this, and the heat treatment furnace may be installed in two upper and lower stages.

[0031]

As described above, according to the present invention, even when works having different heat treatment conditions are continuously conveyed to the same production line, the individual works can be stopped without stopping the line. Depending on the heat treatment conditions, not only heat treatment such as annealing and normalizing, but also any heat treatment including cooling operation such as quenching can be sequentially performed, and at the same time, a cooling liquid tank for quenching and the cooling Since it is not necessary to provide a transfer device for dropping a work into the liquid tank in each of the plurality of heat treatment furnaces, the cost of equipment can be reduced, and the time required for immersion in the cooling liquid tank can be shortened. It has the effect, and furthermore, even if sand accumulates in the cooling liquid tank by quenching the cast product, no pump etc. for discharging this out of the tank is required, so the maintenance cost can be reduced. so Also it has the effect of that.

[Brief description of the drawings]

FIG. 1 is a front view showing a heat treatment apparatus according to the present invention.

FIG. 2 is a side view thereof.

FIG. 3 is a perspective view showing the main part.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Heat treatment furnace 2 ... Heat treatment furnace 3 ... Work transfer device 4 ... Coolant tank 5 ... Work loading / unloading 6 ... Elevator device 7 ... Lift 8 ... Work loading Discharge mechanism 14 ・ ・ ・ Endless chain 23 ・ ・ ・ Sand discharge port

Claims (1)

(57) [Scope of request for utility model registration] 1. A closed box type heat treatment furnace (1, 2) capable of individually setting temperature conditions is arranged in a row with its work loading / unloading port (5) facing the front. (7) equipped with a work loading / unloading mechanism (8) for loading and unloading workpieces
The elevator device (6) that raises and lowers the heat treatment furnace (1, 2)
The cooling liquid tank (4), which is movably disposed along the surface and immerses the high-temperature work carried out from the heat treatment furnaces (1, 2) onto the lift (7), is located at the lower position of the lift (7). The cooling liquid tank (4) is formed with a sand discharge port (23) for discharging the sand dropped from the work and accumulated at the tank bottom together with the cooling liquid in a timely manner. Heat treatment equipment.