JPH0414446Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] This invention has a fan, a heater, and a cooler in a vacuum container, and heats the processed material by causing convection of gas injected into the vacuum container by the fan. The present invention also relates to a vacuum heat treatment furnace designed for cooling.

[Prior Art] Figure 3 shows an example of a conventional vacuum heat treatment furnace.
A vacuum purge atmosphere tempering furnace is shown.

In the figure, 1 is a vacuum container, 2 is a fan, and 3 is a fan 2
4 is a processing object. A heating chamber 6 surrounded by a partition wall 5 is provided in the vacuum container 1 , and the object to be processed 4 is housed inside the heating chamber 6 .

Inside the heating chamber 6, a heater 7 for heating the object 4 is provided, and by driving a fan 2 disposed inside the heating chamber 6, the vacuum container 1 is
The gas injected into the heating chamber 6 is circulated in the following order: fan 2 → heater 7 → workpiece 4 → fan 2.

Also, the partition wall 5 forming the heating chamber 6 and the vacuum container 1
A cooler 9 (cooling coil) is provided in the space 8 between the walls below the heating chamber 6, and the fan 2 is driven by opening dampers 10 and 11 provided at appropriate locations on the partition wall 5. By doing so, the fan 2 → the space 8 between the partition wall 5 and the wall of the vacuum vessel 1 → the cooler 9 →
Gas is circulated in the order of process object 4 → fan 2 mainly through the flow path outside the heating chamber 6.

In this vacuum heat treatment furnace, the process usually proceeds as follows. First, the object to be treated 4 is set in the vacuum container 1, and the container 1 is sealed.
The inside of the container 1 is evacuated and the inside of the container 1 is replaced with an inert gas. After that, the dampers 10 and 11 are closed, and the heater 7
is activated, the fan 2 is driven, and the gas is convected in the flow path indicated by the solid line arrow in the figure, thereby heating the processing object 4.

Also, during subsequent cooling, the dampers 10, 1
1 is opened, the heater 7 is turned off, the cooler 9 is activated, the fan 2 is driven, and the gas is convected along the flow path shown by the dotted line arrow in the figure, thereby cooling the processed material 4.

[Problems to be solved by the invention] As mentioned above, the conventional vacuum heat treatment furnace has a double structure in which the heating chamber 6 surrounded by the partition wall 5 is provided inside the vacuum container 1, and the heating chamber 6 is surrounded by the partition wall 5. , a flow path inside the heating chamber 6 passing through the heater 7 and a flow path outside the heating chamber 6 passing through the cooler 9 are defined separately and in parallel.
Therefore, due to the double structure, the structure is complicated, large in size, and costly.

The object of the present invention is to provide a vacuum heat treatment furnace that has a simple structure and is inexpensive.

[Means for Solving the Problems] The present invention solves the above problems, and includes a flow path A in which gas circulates in the order of the fan, the heater, the processed material, and the fan in the vacuum container. and a flow path B in which gas circulates in the order of fan, heater, cooler, processed material, and fan, a flow path from the heater to the cooler, and a flow path from the cooler to the processed material, simultaneously opening and closing. The present invention is characterized in that a damper for selectively selecting the flow path A and the flow path B is provided.

[Operation] In the vacuum heat treatment furnace described above, during heating, the heater is operated and the damper is closed to select flow path A as the gas convection flow path, and the fan is driven to heat the processed material.

Furthermore, during cooling, the heater is turned off, the cooler is operated, and the damper is opened to select flow path B as the gas convection flow path and cool the processed material.

[Example] Hereinafter, an example of the present invention will be described with reference to FIGS. 1 and 2.

In the figure, reference numeral 21 denotes a vacuum vessel having a circular cross section, and a fan 23 driven by a motor 22 is provided on the ceiling inside the vacuum vessel 21 . fan 2
The central part of the vacuum container 21 below the workpiece 2
4, and heaters 25, 25 are arranged on both sides of the space.

Further, a chamber 27 partitioned by two dampers 26, 26 having substantially horizontal blades is provided in the lower part of the vacuum container 21, and a cooler 2 is provided in the chamber 27.
8 and 28 (of a type that circulates cooling water) are arranged. By opening and closing the dampers 26 and 26, the flow path from the heater 25 to the cooler 28 and the flow path from the cooler 28 to the processed material 24 are simultaneously opened and closed, thereby opening and closing the next two flow paths A, B can be selectively switched.

In the flow path A, the gas flows from the fan 23 to the heater 25
Convection occurs in the order of processed material 24 → fan 23. In the flow path B, the gas flows from the fan 23 to the heater 2.
Convection occurs in the following order: 5→cooler 28→processed material 24→fan 23.

To explain the operation of this vacuum heat treatment furnace, during heating, as shown in FIG. do. At the time of cooling, as shown in FIG. 2, the damper 26 is opened to select the flow path B, and the processed material 24 is cooled by convection of the gas as shown by the dotted arrow.

In the case of this method of convection, flow paths A and B
Regarding the flow path A, it is not parallel, but whether it is through the cooler 28 or not.
It functions as a bypass for the flow path B.

[Effects of the Invention] In the present invention, a heater and a cooler are arranged in series in one flow path B, and during heating, gas is circulated through a bypass flow path A without using a cooler. That is, the flow path passing through the heater and the flow path passing through the cooler are not provided completely parallel and distinct. Therefore, there is no need to provide a partition wall that defines a flow path to form a double structure, and the structure can be extremely simplified and downsized. Therefore, the cost is low.

[Brief explanation of drawings]

1 and 2 show an embodiment of the present invention,
FIG. 1 is a front sectional view showing the state during heating, FIG. 2 is a front sectional view showing the state during cooling, and FIG. 3 is a front sectional view showing an example of a conventional vacuum heat treatment furnace. 21...vacuum container, 23...fan, 24...
Processing object, 25... Heater, 26... Damper, 2
8...Kula.

Claims (1)

[Scope of utility model registration request] A flow path A in which gas circulates in the order of fan, heater, processed material, and fan in the vacuum container; a flow path B in which gas circulates in the order of fan, heater, cooler, processed material, and fan; A damper is provided that selectively selects the flow path A and the flow path B by simultaneously opening and closing a flow path from the heater to the cooler and a flow path from the cooler to the processed material. A vacuum heat treatment furnace characterized by: