JPS63197874A - Vacuum heat treating furnace - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a vacuum heat treatment furnace, and particularly to a vacuum heat treatment furnace that is optimal for use in M-type vacuum brazing.

[Conventional technology and its problems]

Conventionally, in most cases, the heating method of a vacuum heat treatment furnace is a so-called internal heating type, and various parts constituting the heating system, such as a heat insulating plate and a heat insulating plate, are housed therein. For this reason, the inner surface area of the furnace is increased, making the entire furnace larger, and the heating system becomes a source of emitted gas, worsening the degree of vacuum within the furnace.

Furthermore, when maintaining and inspecting the inside of the furnace, the heating system inside the furnace must be taken out to the outside, which increases the working time. Especially in M series vacuum brazing furnaces? Since the metal is deposited over the entire area inside the furnace, the working time is further increased.

In addition, when performing kl brazing, for example, a material with a large area and a small thickness, i.e., a plate-shaped workpiece, should be placed so as to face the heating surface of the heating system to improve the efficiency of heat input. be done. A so-called face heating method has been adopted, but as the area of the material to be processed increases, the space factor within the processing zone decreases, which has been an obstacle to improving productivity.

In addition, in the in-rage method for mass production, that is, the method in which a preparation chamber and a take-out chamber are installed before and after the furnace to enable semi-continuous processing without changing the pressure inside the furnace, the length of the entire vacuum heat treatment furnace is It is large in size and requires a large installation area, which increases the cost of the sliding equipment when installing the device. This also applies to retort heating systems, ie, furnaces equipped with heating means outside the furnace.

[Problem that the invention seeks to solve]

The present invention has been made in view of the above problems, and an object of the present invention is to provide a vacuum heat treatment furnace that can improve the degree of vacuum, reduce the size of the entire furnace, and improve the operating rate.

[Means for solving problems]

The above purpose is to form an inlet at one end of the side wall and an outlet at the other end of the processing chamber, which is heated by external heating means; an airtight gate connected to the inlet and provided at the inlet, which can be opened and closed; A preparation chamber that can be fluidly isolated from the processing chamber by K; an airtight gate connected to the outlet and provided at the outlet that can be opened and closed; In the preparation chamber, the material to be treated is moved in one direction and carried into the processing chamber through the entrance, and in the processing chamber, the material is moved in a direction approximately at an angle from the one direction while being heated by the heating means. Be sure to heat from the entire periphery.
This is achieved by a vacuum heat treatment furnace characterized in that the heat treated material to be treated is changed in direction of movement approximately at an angle and is carried out through the outlet and into the take-out chamber.

[For production]

What about the processing room, preparation room and extraction room? ! Since it extends in the angular direction, the overall installation area can be reduced.

It is possible to improve the degree of vacuum, shorten the work time for maintenance and inspection, and improve the operating rate of the furnace.

〔Example〕

EMBODIMENT OF THE INVENTION Hereinafter, a vacuum heat treatment furnace for aluminum solder according to an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 shows the entire vacuum heat treatment furnace of this example. A processing chamber (2) is formed in the furnace body (1), an inlet (3) is formed at one end of the side wall, and an inlet is located at the other end. is formed with an outlet (4). An elongated rectangular cylindrical guide member Q5 is fixed to the inlet (3) and the outlet (4). A preparation chamber (7) and a take-out chamber (8) are formed in these guide members α51 (6), and gates (5) (6) that can be opened and closed are provided at the inlet (3) and outlet (4). ing. Gate(
5) When (6) is open as shown by the dashed line, the preparation chamber (7) and the extraction chamber (8) are in free communication with the processing chamber (2), but the gates (5) and (6) are open as shown by the solid line. When the chamber is closed as shown in , the chamber is airtightly closed, and the preparation chamber (7), the extraction chamber (8), and the processing chamber (2) are fluidly isolated.

The furnace body (1) is cylindrical and extends long from side to side in FIG. 1, and its openings at both ends are hermetically covered by cover plates (9) Qllll. An exhaust port CIυ is formed at one end of the processing chamber (2), and an exhaust device α9 is connected to this. In addition, an inert gas outlet (2) (inert gas is introduced from the inert gas inlet (12b) on the ring via the pipe (12a)) is provided at the other end of the processing chamber (2). By operating the exhaust device 4, the inert gas flows to the left in the figure as shown by arrow C.

The end QaQ4) of the guide member (to) (4) is provided with a gate α7)Qlll that can be opened and closed, and a buffer tank (211C231) is connected to the outer wall, and an exhaust system cl is connected to these tanks [21++231]. !Ill!
■ is connected. Further, a carrier return device 1241 is provided between the guide members Q5(4).

As shown in FIGS. 1 and 3, a resistance heating source (C) is arranged around the outer periphery of the furnace body (1), and according to this embodiment, this is divided into a plurality of (eight) parts. and each is controlled by a separately provided controller (not shown) so as to heat the inside of the processing chamber (2) with the temperature gradient shown in FIG. ), the direction from the left to the right as indicated by the arrow is the direction in which the workpiece (support), which is the material to be processed, is transferred. The temperature is controlled to vary as shown in Figure 2.At the position Pi corresponding to the inlet (3), the temperature is To, and up to a certain position this temperature remains constant, but beyond this position The heating source rigidity is adjusted so that the temperature increases at a predetermined gradient, and becomes a constant value LfM at a position slightly beyond the center of the processing chamber (2), and gradually decreases from a certain position near the exit (4). The current is controlled.In this embodiment, a so-called "master-slave" heating control method is adopted, in which the control temperature at a certain point is used as a reference temperature, and the temperature at other points is set to a reference temperature. I try to control it by giving it a certain width.

According to this embodiment, the workpieces to be processed are plate-shaped, and two workpieces are transported by one carrier α, but three or four workpieces can be transported depending on the production volume. Transport is also possible. The work tXS+ is, for example, AI-8i-M
This is a heat exchanger assembly that is pre-clad with a brazing filler metal made of the three elements f.

As shown in Figure 3, a conveyor break is provided in the longitudinal direction of the clay wall of the furnace body (1), and a carrier @ is suspended from this to convey the workpiece. There is. Although the details of the conveyor 129 are not shown, the bearings are made of high-temperature material. A similar conveyor (not shown) is also provided in the preparation chamber (7) and unloading chamber (8) in the guide member (to) (4), and the carriers are suspended from this and conveyed. ing. Note that, due to a known structure, the conveyor is installed so as not to interfere with the opening and closing of the game (5) (a).

The carrier waste is transported along the direction of the arrow by the transport machine in the preparation room (7), and is carried into the processing room (2). The carriers are transported in the direction of the arrow by the transport machine in the processing chamber (2), but the carriers are transported from the transport machine in the preparation room (7) to the transport machine in the processing chamber (2). Although not shown, a known means is used as the transfer means to
From c), the workpiece ■ is transferred in the same position as the arrow ^
It is transported in the direction shown.

Note that heating means (not shown) are also provided around the outer peripheries of the preparation chamber (7) and the extraction chamber (8), so that the interior temperature is maintained at a predetermined temperature, e.g.
It is heated to 50-200°C. Further, in order to shorten the exhaust time and thereby shorten the cycle time of this system, a large-capacity exhaust device QQQ21 is used.

The embodiment of the present invention is constructed as described above, and its operation will be explained next.

In the preparation room (7), the gate (5) is closed and the gate αη is opened. Buffer tank Q even if not shown
The valve between υ and the exhaust system is closed, and the preparation room (
7) The pressure inside is assumed to be atmospheric pressure. Carrier return device (to)
The carrier surface and workpiece transported from the preparation room (7
). Next, the gate Q71 is closed and the interior of the preparation chamber (7) is evacuated. The inside of the chamber (7) is heated to a predetermined temperature, and by opening the pulp (not shown), the buffer tank (211) and the chamber (9 yen) are in communication with each other. 7) The inside is rapidly evacuated.

After a predetermined period of time, the gate (5) is opened, and the returned material is held on the carrier surface by a transporter (not shown) and transferred to the processing chamber (2).
Inward and arrow people are carried along the direction. Processing room (2)
The inside is evacuated to a predetermined degree of vacuum by an exhaust device α9, and the workpiece is transferred in the direction shown by the arrow by the conveyor 4 in the posture shown in the figure. During this transfer, the workpiece is heated by the heating source from the peripheral edge, as is clear from FIG. 3, so the temperature rises faster than in the conventional 7-Ace heating system, and the heat uniformity is also good. As the workpiece 281 is transferred, it is heated with a temperature gradient as shown in FIG. 2, and then maintained at a predetermined temperature. During this time, good At brazing is performed. After this, the temperature decreases with a gradient as shown in Figure 2, and the wax solidifies, leaving the outlet <4)K at the corresponding position P
Leading to O.

In the extraction chamber (8), the gate (to) remains closed, but the gate (6) is opened. Since the extraction chamber (8) is already evacuated, the degree of vacuum in the processing chamber (2) hardly changes. The workpiece is transferred from the conveyor in the processing chamber (2) to the conveyor in the take-out chamber (3), with the workpiece in the same position.
That is, the transport direction is changed to a right angle and the film is transported into the extraction chamber (8) along the arrow 4. The gate (6) is closed, the gate (to) is opened (the open pupil is indicated by a chain line), and the extraction chamber (8) is exposed to the atmosphere. Open carrier and processed workpiece (
The carrier is removed and transported to the preparation room (7) by the carrier return device (to). The processed workpieces (to) are taken out while being conveyed by the carrier and return device (2), and unprocessed workpieces are loaded therein. Next, the gate α force is opened (the carrier (2) and the workpiece r28 whose open position # is indicated by a dashed line) are inserted into the preparation chamber (7).

In addition, although the carrying-in of the work mark from the preparation room (7) to the processing room (2) and the carrying-out from the processing room (2) to the take-out room (8) have been explained separately above, it is assumed that these are carried out at the same time. It's okay.

In the processing chamber (2), the carrier surface is transferred in the direction indicated by the arrow, and inert gas C is transferred to the processing chamber (2) in the opposite direction.
2) Being swept away inside. As a result, when the return ■ reaches the final processing temperature, it will not be contaminated by the gas released from the workpiece ■ in the preparation room (7) side, and the processed workpiece (to) will be taken out of the takeout room in a clean state. It is taken out to (8). Furthermore, due to the temperature gradient shown in Fig. 2, the workpiece (2) is taken out to the removal chamber (8) after the wax has solidified after brazing, thereby preventing brazing defects. Can be done.

The embodiments of the present invention perform the above-mentioned functions, but also have the following effects.

Since no heating means is provided inside the processing chamber (2),
The source of emitted gas can be greatly reduced, and the degree of vacuum, that is, the value of the atmosphere can be improved. Furthermore, since it is not necessary to remove or attach the heating means from the processing chamber (2), which is difficult, the maintenance work time can be greatly reduced.

When the M wax melts in the processing chamber (2), Mf evaporates, but according to this embodiment, the inside of the processing chamber (2) is heated with a temperature gradient as shown in FIG. Because inert gas is flowing in the opposite direction, the temperature is low in the preparation room (7
) It is possible to concentrate the adhesion on the nearby chamber walls, which makes maintenance easier and further improves the shortening of maintenance time due to the absence of heating means as described above. As a result, the operating rate of the furnace can be greatly improved.

Furthermore, since the workpiece is heated from the entire periphery, the utilization efficiency (space factor) of the effective heating zone is improved, and productivity is improved. Therefore, the installation area of the furnace can be reduced to 1/2 to 1/3 of that of a conventional in-line furnace. In particular, in this embodiment, when carrying a workpiece into the processing chamber (2), the direction of transfer from the preparation chamber (7) into the processing chamber (2) is changed at right angles. Therefore, the width of the gate (5) can be reduced, and the width of the gate (6) in the extraction chamber (8) can also be reduced.
Since the width of the guide member α can be reduced, the installation area of the entire furnace can be further reduced. If a preparation chamber and an unloading chamber are connected before and after the cover plate (9) α0L7) of the furnace body (1), and the workpieces are taken in and out by opening and closing the cover plate (9) (10), the size will be even larger than in this example. It will become.

Although the embodiments of the present invention have been described above, the present invention is, of course, not limited thereto, and various modifications can be made based on the technical idea of the present invention.

For example, in the above embodiment, two works (281) are placed on the carrier (5), but the number is not limited to this, and may be one, or three or more.

Furthermore, in the above embodiments, a hanging type conveyor was used to convey the workpieces within the six spaces (2), (7), and (8), but the invention is not limited to this; You may also use Alternatively, a hanging type conveyor may be used in the chamber (2), and a mounted type conveyor may be used in the chambers (7) and (8).

Furthermore, although the above embodiments have been explained using an M wax, the present invention is applicable to a general processing furnace.

In addition, in the above embodiment, a resistance heating element (T) is used as the heating part.
was used, but instead of this, induction heating may be used.

〔Effect of the invention〕

As described above, according to the vacuum heat treatment furnace of the present invention, the installation area of the furnace can be reduced and productivity can be improved.
It also shortens furnace maintenance and inspection work and further improves furnace operation rates.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a vacuum heat treatment furnace according to an embodiment of the present invention, FIG. 2 is a graph showing the heating temperature at each position in the work transfer direction of the processing chamber in FIG. 1, and FIG. 3 is the graph shown in FIG. 1. FIG. In 7 & diagram,

Claims (9)

[Claims] (1) A processing chamber that has an inlet at one end and an outlet at the other end of the side wall, and is heated from the outside by a heating means; connected to the inlet, and an airtight gate provided at the inlet that allows fluid to flow through the chamber. a preparation chamber that can be electrically isolated from the processing chamber; an extraction chamber that is connected to the outlet and can be fluidically isolated from the processing chamber by an airtight gate that can be opened and closed at the outlet; The material to be processed is moved in one direction and carried into the processing chamber through the entrance, and in the processing chamber, while being moved in a direction substantially perpendicular to the one direction, the material is heated from almost the entire periphery by the heating means. A vacuum heat treatment furnace characterized in that the heat-treated material is heated, and the heat-treated material is moved in a substantially perpendicular direction to be carried out through the outlet and into the take-out chamber. (2) The heating means gradually increases the heating temperature along the transport direction of the material to be processed in the processing chamber, maintains a predetermined temperature, and then gradually lowers the heating temperature. The vacuum heat treatment furnace according to item 1 above. (3) The vacuum heat treatment furnace according to item 2, wherein the heating means includes a plurality of heating sections, and these are controlled depending on the position in the transfer direction. (4) The vacuum heat treatment furnace according to item 3, wherein the heating section is a heating means using an electric resistance heating element or induction heating. (5) The vacuum heat treatment furnace according to any one of items 1 to 4, characterized in that the transfer speed of the material to be processed in the processing chamber is variable. (6) The vacuum heat treatment furnace according to any one of the above items 1 to 5, wherein an inert gas is caused to flow in the processing chamber in a direction opposite to a direction in which the material to be processed is transferred. . (7) The vacuum heat treatment furnace according to any one of items 1 to 6, wherein the extraction chamber and/or the preparation chamber are heated to approximately a predetermined temperature. (8) A buffer tank that can be fluidly shut off is connected to the extraction chamber and/or the preparation chamber, the buffer tank is evacuated in advance, and when the extraction chamber and/or the preparation chamber is evacuated, the 8. The vacuum heat treatment furnace according to any one of Items 1 to 7, characterized in that the furnace is fluidly connected to a buffer tank and is rapidly evacuated. (9) The vacuum heat treatment furnace according to any one of items 1 to 8, wherein the means for transferring or conveying the material to be treated includes a bearing, and the bearing is made of a high-temperature material.