JPS60187620A - Vacuum furnace - Google Patents

Abstract

PURPOSE:To provide a vacuum furnace which is suitable for not only high-temp. heating but low-temp. heating as well by attaching a stirring fan for the gaseous atmosphere in a furnace in such a way that the fan can be freely put into and out of a heating part. CONSTITUTION:A material (a) to be heated which is loaded and placed in a heating chamber 1 connecting in series via an intermediate door to a cooling chamber is heated by an electric heater 13 disposed on the inside of a heat insulating material 11 in a heating part 12 formed of the heat insulating material 11 provided to enclose the material to be heated. A stirring fan 17 is provided through a window 16 opened in the deep part of the heating part 12 so as to face the material (a) and a motor 18 which revolves said fan is supported by a carriage 20 disposed freely slidably on rails 19. Low-temp. heating is executed by loading a gaseous atmosphere into the chamber 1, advancing the fan 17 through the window 16 to the inside of the part 12, closing the window 16 by a disk 22 made of the heat insulating material and revolving the fan 17 to stir the gaseous atmosphere around the material (a) and accelerating the convectional heat transmission. On the other hand, the inside of the chamber 1 is evacuated, the fan 17 is retreated and the cover 24 is closed in the case of high-temp heating.

Description

[Detailed description of the invention] The present invention relates to the structure of a vacuum furnace.

In a vacuum furnace, the object to be heated is heated to a high temperature of /200 to 1 too@C, mostly due to radiant heat transfer from the heater, and almost no convection heat transfer or conduction. When heating an object to a high temperature in this way, the inner surface of the heater or insulation material is at a high temperature, so the temperature can be raised in a short time using only radiant heat, but tempering, annealing, etc./5O- When attempting to heat an object to a relatively low temperature of about 600@C, a vacuum furnace has the disadvantage that it takes much more time than other ambient air furnaces because there is almost no convective heat transfer. Therefore, if necessary, add argon gas to the vacuum furnace.
Inject the ambient air gas from the Chisso gas station and raise the pressure inside the furnace to 100-7.
It is conceivable to set the temperature to 40 TOrr and promote heating by convection heat transfer, but vacuum furnaces are generally not equipped with a stirring device, and only natural convection occurs, resulting in inconveniences such as uneven temperature distribution within the furnace. Ta. Therefore, it is conceivable to provide a stirring device in the furnace to stir the atmospheric gas, but /2
It is quite difficult to manufacture a stirrer that can withstand high temperatures of 0.00 to 0.00 to 0.00 to 0.000, and even if it were made of highly heat-resistant fine ceramics or the like, it would be expensive.

The present invention aims to eliminate the disadvantages of the queen and provide a vacuum furnace suitable not only for high-temperature heating but also for low-temperature heating, and is characterized in that a device for stirring the surrounding gas inside the furnace is provided in the heating section so as to be able to move in and out. It is something to do.

Next, one embodiment of the present invention will be described with reference to the drawings.

In this vacuum furnace, a heating chamber 1 and a cooling chamber 2 are connected in series, and an intermediate Hs is provided between the two chambers, and the cooling chamber 2 is opened and closed for charging and extracting heat materials. 4 is provided. Reference numeral 5 denotes a fork-shaped lift on which the heated object a is placed, and the core lift enters the cooling chamber 2 and the heating chamber 1 along the lift rail 6 provided on the ceiling and carries the heated object a into the chamber. and carry out. Reference numeral 7 indicates a cooling atmosphere gas circulation fan provided in the cooling chamber 2.

8 is the tip of the operating shaft in the middle 5i! 3, by operating the cylinder when the intermediate door 3 is opened, the intermediate door 3 is retracted into the storage section 9 and becomes a hindrance to loading and extracting the heated object a into the heating chamber 1. Make sure it doesn't happen.

In the heating chamber 1, a fixed stand 10 on which an object to be heated a is placed is arranged, and a heat insulating material 1 made of graphite with excellent heat resistance is provided to surround the object to be heated. A WL thermal heater is placed inside the heat insulating material 11. 14 temporarily removes the heated object a carried on the lift 5 when it is lowered onto the fixed table 10 and when the heated object a on the fixed table 10 is placed on the lift 5 again. A lifting rod 15 is provided on the fixed base lO to support the heating rod, and 15 indicates a cylinder for operating the lifting rod. Therefore, a window 16 is opened in the inner part of the heating part ν surrounded by the heat insulating material 11, A stirring 17 is placed so as to face the heated object a from the nitrogen 16.
A motor slide for rotating the agitation 17 is installed on the rail 1.
The motor is supported by a carriage mounted slidably on top of the motor.
The operating shaft end of the cylinder 2] is connected to the back of the cylinder 21, and the operation of the cylinder 21 causes the motor arm to slide along the rail 19, and the stirring 17 advances or retreats from the holder 16 into the heating section ν. Configure to obtain. Note that n is 17 for stirring]
motor 18 for closing said window 16 when
A disk made of insulating material fixed to the front of the motor 1.
8 with a stopper provided on the outer periphery. An example is a cover plate made of a heat insulating material that closes the stirrer 16 when the stirring unit 17 is retired, as shown in Figure 1. The window 16 is opened and closed by the operation of the cylinder δ connected to the end.

In the vacuum furnace constructed in this way, during low-temperature heating, atmospheric gas is charged into the heating chamber 1, and as shown in FIG. 17 is rotated to stir the atmospheric gas in the heating part n around the eyebrows of the object to be heated 8, thereby promoting convective heat transfer and uniformly heating the object to be heated S in a short time.

On the other hand, when heating at a high temperature, the inside of the heating chamber 1 is evacuated, the stirring unit 17 is turned off, and the lid plate U is closed, as shown in FIG. In this way, the stirring unit 17 can be prevented from overheating without receiving radiant heat from the heating section ν. Note that the stirring 17 does not require special heat resistance for this purpose, and an existing one can be used, but it is desirable that the number of rotations can be adjusted in order to balance the temperature distribution and heating capacity.

As explained above with respect to the embodiments, the vacuum furnace of the present invention has the following features:
By providing a stirrer that can move in and out of the heating section,
When heating at low temperatures, the stirrer is activated to enable uniform heating in a short time, and when heating at high temperatures, the stirrer is removed from the heating section so there is no risk of overheating, so it can be used efficiently for both purposes. ! 31 has remarkable effects.

[Brief explanation of the drawing]

The drawing shows an embodiment of the vacuum furnace according to the present invention.
FIG. 1 is a partially sectional side view thereof, FIG. 2 is an enlarged longitudinal sectional view showing the operating state of the main parts, and FIG. 3 is a sectional view taken along the line XX of FIG. a...Heated object, 11...Insulating material, 12...
heating section. m...! [Thermal heater, 16...window, 17...
・For stirring, 18...Motor, 24...Lid plate. Patent applicant: Daido Special Copper Co., Ltd.

Claims (1)

[Claims] A vacuum p characterized in that a device for stirring the atmosphere gas in the furnace is installed in the heating section so that it can be moved in and out.