JPS6049696B2 - billet heating furnace - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a built-in heating furnace for preheating a billet when hot extruding aluminum or drawing or hot forging steel.

In conventional billet heating furnaces, the billet was generally introduced into the furnace along its length and pulled out after heating, which made it difficult to uniformly heat the entire surface of the billet.
In addition, the billet storage space requires a large area, and since the work is done in batches, certain processes such as billet accumulation, preheating, and processing must be performed intermittently, resulting in low work efficiency.

The present invention has been made in order to completely eliminate the defects of the conventional billet heating furnace as described above. A billet heating furnace equipped with a plurality of billet stoppers perpendicular to the direction of inclination of the floor, and a billet pushing device that sequentially rolls a billet having a circular cross section that is stopped by the stoppers over the stoppers to the next stopper. This is what we are trying to provide.

Hereinafter, the present invention will be described in detail based on embodiments shown in the drawings.

FIG. 1 is a side sectional view showing an embodiment of a billet heating furnace according to the present invention.

That is, the heating furnace is provided with a ceiling 1 and a bottom 2 made of refractory bricks, a billet inlet 3 and an outlet 4, and has slide doors 5 and 6 that open and close the respective openings 3 and 4 to form an almost airtight casing. This is to prevent heat dissipation.

Then, gas is placed near the built-in exhaust port 4 in the ceiling 1.
The required number of burner flame radiation holes, 7, ...... are drilled in a staggered manner, and the gas supply pipes 8, J8, ...
Gas burners 9, 9, . . . extending from .
to be fixed.

Further, an exhaust pipe 10 is installed in the vicinity of the built-in inlet 3 on the ceiling 1, and the gas burners 9, 9, . . .
This allows for complete combustion of the fuel, and allows fine adjustment of the temperature inside the furnace by adjusting the opening angle of the butterfly valve 11 in the exhaust hole 7.

Further, the gas burners 9, 9, . . . on the ceiling 1
A platinum-platinum-rhodium thermocouple 12 is buried in the inner surface of the intermediate portion between the gas burners 9, 9, and the exhaust pipe 10 to monitor the temperature inside the furnace and to control the discharge of the gas burners 9, 9, . . . The flame ON/OFF and the opening degree of the butterfly valve 11 are controlled. On the other hand, a little space is provided from the bottom 2 of the furnace,
Three rail-shaped hearths 13, 13, 13 are arranged on the same plane as the bottoms of the billet input port 3 and the billet discharge port 4, and the slope thereof is approximately 11 mm from the billet input port 3 toward the discharge port 4.
10, and cylindrical built stoppers 14, 14, . . . perpendicular to the rail 13 are fixed at predetermined intervals on the rail 13.

Furthermore, between the rail-shaped hearths 13, 13, 13, there are built-up rails 15, 15, which can be raised and lowered in parallel thereto.
... are arranged separately, and the push-up rails 15, 15
Rods 16, 16, . . . connected to the bottoms of the furnace bottoms 2 are integrated into the elevating table 17 by penetrating the refractory wire tiles of the hearth bottom 2, and this is raised and lowered using a hydraulic cylinder 18 to form a billet. Configure the push-up device.

The cylindrical projections 19, 19, . . . on the rails 15, 15, .
, 20 are guide rails of the elevating table 17. A billet charging hopper 21 is provided outside the billet charging port 3 of the heating furnace as described above, and this rotating shaft 22 is rotated by an air cylinder 24 via a lever 23 to open the billet charging port sliding door 5. Billet 25 according to opening and closing
, 25, ... into the furnace.

Note that 26 and 27 are hydraulic cylinders for opening and closing the sliding doors 35 and 6, respectively.

Further, the arms 28 and 29 provided near the billet inlet 3 and the billet outlet 4 in the furnace are actuators of sensors that detect the charge and discharge of the billet 25, respectively. The rotating shafts 30 and 31 each pass through the furnace side wall to drive a micro switch provided outside the furnace. FIG. 2 is a front sectional view taken along the line A-A in FIG.
2 is driven.

Further, a small hole 33 is provided in one side wall of the heating furnace according to the present invention, and a crimp-type temperature sensor 34 is inserted and retracted through the hole 33 to detect the temperature of the end face of the billet immediately before the billet discharge port 4.

Reference numeral 35 denotes an air tank that causes the pressure-bonding type temperature sensor 34 to appear and disappear.
It is a cylinder, and 36 is a lid that closes the small hole 33.

7. It goes without saying that the drive timing of the billet lifting devices 15, 16, 17 and 18, the billet discharge port sliding doors 5 and 6, the billet charging hopper 21, etc. is determined by detecting the billet temperature.

The billet heating furnace of the present invention constructed as described above operates as follows.

Now, assuming that there is no billet in the furnace and the operator turns on power to the built heating furnace of the present invention, the microswitches connected to the actuators 28 and 29 of the sensor, respectively, will indicate that there is no billet. A signal will be issued.

In response to this signal, a pump (not shown) is activated to drive the hydraulic cylinder and pull up the door 5 of the billet inlet.

In conjunction with this operation, a high-pressure air generator, also not shown, operates to drive the air cylinder 24, thereby rotating the hopper 21. The billet 25 waiting in the hopper 21 is charged into the furnace through the billet inlet 3 and stopped at a first billet stopper 14 provided on the hearth 13 while rolling.

In this manner, the actuator 28 of the sensor rotates against the billet, so that the sensor issues a signal that one billet has been deposited.

Based on the logic of this signal and the signal indicating that there is no billet emitted by the sensor near the billet discharge port, the hydraulic cylinder 18 of the billet lifting device is driven, and its protrusion 19 moves the billet 25 to the second position. The billet is rolled up to the billet stopper 14, and the door 5 of the billet inlet is closed. At this point, both of the sensors again issue a signal indicating that they have not detected the build, so that the same operation as described above can be repeated. This operation is repeated until a predetermined number of builds are placed in the furnace. Meanwhile, in parallel with the above-mentioned operation, the gas burners 9, 9, . . . are ignited to raise the temperature inside the furnace.

The charged billets 25, 25, . . . move toward the billet discharge port 4 while rolling sequentially, so that they are uniformly heated all around. Now, the first billet is the sensor/actuator 2 near the billet discharge port.
When the temperature reaches 9, the driving air cylinder 35 of the crimp-type temperature sensor 34 is activated by a signal to that effect, and the sensor 3 is activated.
4 is pressed against the built-in side end through a hole 33 provided in the side wall of the furnace. When a signal indicating that the temperature at the billet side end has reached the desired temperature is issued from the sensor 34, the hydraulic cylinder 27 operates to open the billet discharge port door 6, and at the same time, the hydraulic cylinder 18 is also operated. Finally, all the birzut in the furnace are pushed up into one room.

As a result, the leading billet is discharged from the billet discharge port 4 onto a billet conveying device (not shown) and sent to the next process such as an extrusion molding or drawing machine, while the billet remaining in the furnace is rolled and rolled. Move to the billet ● stopper 14, 14, . . . just one point ahead. At this time, the sensor ◆actuator 28 near the billet input port does not detect the billet, so the sensor issues a signal to that effect.

This signal causes the billet inlet door 5 and hopper 21 to operate again to add a new billet. The billet heating furnace according to the present invention operates as explained above, but the sequence and sequence for performing such operation are
The control circuit can be configured in any manner and does not necessarily need to operate in the order described above, so the description has been omitted to avoid complication.

Furthermore, the present invention is not necessarily limited to the above-described embodiment; for example, a billet pushing device may be provided for each billet so that billets can be continuously fed in at the start of the heating operation. Alternatively, instead of the billet charging hopper, a slope having the same slope as the hearth may be provided at the billet inlet, and a large number of billets may be lined up on this slope and sequentially charged as the door is opened and closed.

Note that it is obvious that the heat source is not limited to gas but may also be electricity. Since the present invention is constructed and operates as described above, it is possible to continuously perform billet heating operations in pre-processes such as hot drawing or forging of aluminum billets for extrusion molding or general steel materials.

At that time, a temperature difference is naturally required for heating non-ferrous metals and general steel materials, but since the temperature difference can be adjusted using a temperature sensor, the heating furnace of the present invention can be used. Since it is possible to uniformly heat the entire surface of various buildings, it is extremely effective in improving the efficiency of a series of operations such as stacking, stacking, preheating, and processing buildings.

[Brief explanation of the drawing]

FIG. 1 is a side cross-sectional view showing one embodiment of a billet heating furnace according to the present invention, and FIG. 2 is a cross-sectional view taken along line A-A thereof. 1... Billet inlet, 4... Billet outlet, 13... Hearth, 14... Billet stopper, 15, 16, 17, 18, 19 and 20...Gelette pushing device, 25...Billet.

Claims (1)

[Claims] 1. A hearth that descends at a required inclination from a billet input port to a discharge port that can be opened and closed, and a plurality of billet stoppers orthogonal to the inclination direction of the hearth, and a circular cross section that is stopped by the stoppers. By providing a billet pushing device that sequentially rolls a billet over the stopper to the stopper in front of the billet, the billet introduced from the billet inlet can be locked by the stopper and rolled by the billet pushing device. A billet heating furnace characterized in that the billet is heated continuously and uniformly over the entire surface by a heat source within the furnace while repeating the above steps at a required time interval.