JPS5823836B2 - Cooling system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cooling device installed in a furnace for heat-processing a workpiece to cool the workpiece after heat-processing. It is suitable for use in workpieces.

Generally, when heating a workpiece in a furnace,
In order to shorten the processing cycle, the workpiece is cooled after heat processing, but if the workpiece does not like oxidation during heat processing, it is necessary to perform heat processing in an oxygen-free condition. For this purpose, vacuum heat treatment furnaces, vacuum brazing furnaces, etc. are used.

According to such workpieces, cooling after heating processing must also be performed in an oxygen-free state, and the conventional cooling devices used in the above-mentioned vacuum heat treatment furnaces, vacuum brazing furnaces, etc. have a rough structure. As shown in FIGS. 2a, b and c.

That is, Fig. 2a shows a cooled gas that does not contain oxygen;
For example, inert gas such as argon, hydrogen gas, etc. are introduced into the furnace 3a from the cooling gas introduction pipe 1a via the on-off valve 2a, while the heat exchanger 6 is introduced from the cooler 4a through the circulation pipe 5ak.
The gas around the heat exchanger 6a is cooled by the cooling liquid supplied to the furnace 3a, and the cooled gas is blown by the blower 7a toward the workpiece 8a installed in the furnace 3a. be.

However, in an actual device, a heater, a heat insulating material, or a support member for the workpiece 8a (
jig) etc. are placed, and if it remains as it is, the workpiece 8a
The workpiece 8a cannot be cooled efficiently.
There is also a method in which these members are moved back during cooling of the workpiece 8a so that the cooling gas from the blower 7a is directly blown onto the workpiece 8a, but this has the disadvantage of complicating the mechanism.

Similarly to the above-mentioned example, FIG. 2 shows that a cooled gas not containing oxygen is introduced into the furnace 3b from the cooling gas introduction pipe 1b through the on-off valve 2bt, while a cooling liquid is supplied around the furnace 3b. A large number of flow pipes 9b are arranged to cool the entire furnace 3b, and since the structure is simple, it is often used in small furnaces, test furnaces, etc., but the workpiece 8b It has the disadvantage that it cannot be cooled efficiently.

Furthermore, FIG. 2C is provided with a cooling chamber 11c that communicates with the furnace 3c through a gate valve 10c, and since the workpiece 8c after heat processing is carried out to the cooling chamber 11c, continuous operation of the furnace 3c is possible. This makes it possible to shorten the machining cycle.

On the other hand, in this example, the working floor area or the space occupied by the apparatus is required to be at least twice as large as the workpiece 8c, and therefore, in the case of a large workpiece 8c, the entire apparatus becomes extremely large. There were drawbacks.

In this way, conventional cooling devices used in vacuum heat treatment furnaces, vacuum brazing furnaces, etc. that heat workpieces in an oxygen-free state cool the workpieces using gas as a medium, as described above. This makes it impossible to cool the workpiece efficiently, and this becomes a major drawback especially when the workpiece is large.

In other words, it is a general characteristic of gas that the thermal conductivity is low, and furthermore, as the size of the workpiece increases, the heat capacity tends to increase relative to its surface area.

In addition, as shown in Fig. 1, two or more workpieces 1゜1' are stacked in the furnace 2 and fixed with appropriate jigs 3, 3', while oxygen-free gas such as argon or hydrogen is Heater 4 below
, 4' to heat the workpieces 1, 1' and join them by mutual diffusion. Furnace pressure welding is a method for joining dissimilar materials that are difficult to weld, such as metal and ceramic. It has been recognized that it is particularly suitable for manufacturing clad steel plates made of high-grade metals such as titanium or zirconium, and there are great expectations for its future potential. Since it is necessary to bond I'a to each other (heat processing) under an oxygen-free condition, the workpieces 1 and 1 after bonding must be
The efficiency of cooling is an important issue that greatly affects the shortening of the processing cycle and the commercialization of furnace pressure welding.

In this furnace pressure welding, jigs 3 and 3', which have almost the same temperature as the workpieces 1 and 1, exist as heat retainers, and in many cases, these jigs cover the upper and lower surfaces of the workpieces 1 and 1. Since the workpieces 1 and 1 are placed in the furnace 2, the cooling efficiency for the workpieces 1 and 1 is further deteriorated. There was a desire to develop a cooling device that could provide good cooling.

The present invention addresses these conventional demands by focusing on the fact that by cooling the jig that is in direct contact with the workpiece, the workpiece can be effectively cooled using the jig as a medium. The purpose of the present invention is to provide a cooling device that can efficiently cool workpieces subjected to heat processing in an oxygen-free furnace after heat processing. The aim is to efficiently cool the

In order to achieve this object, the present invention has a structure in which a jig for supporting the workpiece is installed inside a furnace for heating and processing the workpiece, and a cooling gas passage for cooling the jig and the workpiece. A furnace gas discharge is provided in the jig in a direction facing the workpiece and in a direction intersecting with the workpiece so as to communicate with the inside of the furnace, and guides the cooling gas that has been cooled to the outside of the furnace. A specific example in which the present invention is applied to pressure welding in a furnace will be described in detail with reference to FIG. 3 showing the schematic structure of this specific example. do.

In the furnace 21, a pair of pressurizing jigs 22a and 22b, consisting of an upper and a lower member, which are movable relative to each other toward the other, are attached.
b and is clamped under pressure and fixed in the furnace 21.

This pressure jig 22 is inside the pressure jig 22a, 22b.
, 22b, a first cooling gas passage 24 is bored from one end protruding outside the furnace 21 toward the workpiece 23, and FIG. As shown in the figure, a second cooling gas passage 25 is radially bored extending perpendicularly from the first cooling gas passage 24 and communicating the first cooling gas passage 24 with the inside of the furnace 21 .

The first cooling gas passage 24 at one end of the pressurizing jigs 22a, 22b is connected to a gas cooler 26 installed outside the furnace 21, and has a movable seal or a flexible cooling gas introduction pipe 27. They are connected via an on-off valve 28.

Further, an in-furnace gas exhaust pipe 29 that connects the inside of the furnace 21 and the gas cooler 26 is provided with an on-off valve 30 and a pressurizing jig 2 that sucks the gas in the furnace 21 toward the gas cooler 26 and returns it to the gas cooler 26 .
2a.

A vacuum pump 31 is attached to introduce the cooling gas into the furnace 21 from the second passage 25 in the second passage 22b.

Furthermore, a gas cooler 26 and a cooling gas introduction pipe 2 are installed on the outer peripheral surfaces of the pressurizing jigs 22a and 22b by a vacuum pump 31.
7. Cooling gas blown into the furnace 21 from the second cooling gas passage 25 through the first cooling gas passage 24 in the pressurizing jigs 22 a and 22 b pressurizes the other side along the outer peripheral surface of the workpiece 23 Jig 22b.

A guide plate 32 is fixedly provided so as to flow toward 22a.

When the welding (heat processing) of the workpiece 23 is completed, the on-off valve 2
8 and 30 are opened, and at the same time, the vacuum pump 31 is activated, and the oxygen-free gas cooled by the gas cooler 26 flows through the cooling gas first and second passages 24 and 25 in the pressurizing jig 22 a t 22 b. When passing through, the flow velocity of the cooling gas in this part becomes very high, so the surface heat transfer coefficient becomes large, and the pressure jigs 22a and 22b are effectively cooled, and the cooling gas is cooled by the guide plate 32. The gas flows out from the second passage 25 into the furnace 21 along the outer peripheral surface of the workpiece 23 and cools the workpiece 23 from its surroundings.

The cooled gas blown into the furnace 21 is fed by the vacuum pump 31 from the furnace gas discharge pipe 29 to the gas cooler 26, and then again to the pressurizing jig 22a.

22b and the workpiece 23.

When the temperature of the pressurizing jigs 22a, 22b decreases due to the cooling gas, the pressurizing jigs 22a, 22b
a, 22b and the workpiece 23 from the contact surface with the workpiece 23
directly absorbs the heat, and quickly lowers the temperature of the workpiece 23.

In this specific example, in order to cool the workpiece 23, the pressure jigs 22a and 22b are cooled and the pressure jig 22a is cooled.
, 22b and the workpiece 23 because the heat conduction at the contact surface is utilized.

In order to cool the cooling gas more effectively than 22bk, the diameters of the first and second cooling gas passages 24, 25 are made smaller, and a large number of them are provided in the pressurizing jigs 22a and 22b.
, 22b and the workpiece 23, and it is wise to increase the flow rate of the cooling gas flowing therethrough to increase the surface heat transfer coefficient.

FIG. 4 shows a pressurizing jig 22a in the above specific example.

This figure shows a schematic structure of another example of the cooling device according to the present invention, in which the first and second cooling gas passages 24 and 25 in the cooling gas passage 22b are modified to correspond to the shape of the workpiece 23'.

In this specific example, multiple sets of workpieces 23' are to be joined at the same time, and the jig 33 is designed to support and fix the workpieces 23' at regular intervals. A second cooling gas passage 25 is bored through which the groove-shaped passage 34 to be formed communicates with the inside of the furnace, and this installation is done using a jig 3.
3, the pressurizing jig 33 is in a state of being pressurized and clamped by the pressurizing jigs 22a' and 22b'.

Pressure jig 22a'. A first cooling gas passage 24' is bored in 22b' and communicates with a passage 34 formed by the workpiece 23' in the mounting jig 33 through a connection port 35 provided in the mounting jig 33. has been done.

In this specific example, as in the above specific example, the pressure jig 22a',
Although the cooling gas second passage 25 is not provided in 22b',
Pressure jig 22a.

A second, identical cooling gas passage may be provided to facilitate cooling of 22b'.

The cooling gas is supplied from the first cooling gas passage 24' in the pressurizing jigs 22a' and 22b' to the passage 34 between the workpieces 23' and the second cooling gas passage 2 through the connection port 35 of the mounting jig 33.
5' into the furnace.

Therefore, in addition to being cooled by the cooling gas, the pressurizing jig 22a has a lower temperature than the workpiece 23'.

The mounting jig 22b' directly absorbs the heat of the workpiece 23' through the contact portion between the pressure jigs 22a' and 22b' and the mounting jig 33 and the workpiece 23'.

In the above-mentioned specific example, the cooling device according to the present invention was applied to pressure welding in a furnace, but in the case of a vacuum heat treatment furnace, a vacuum bruising furnace, etc., a jig that supports the workpiece in these furnaces may be used. First, the temperature of the jig is lowered than that of the workpiece, and the heat of the workpiece is absorbed into the jig from the contact area between the jig and the workpiece. If this is done, it is possible to expect exactly the same effect as in the above specific example.

Conventionally, it is not possible to efficiently cool a large-volume workpiece or a jig that supports it by using cooling gas from the outer periphery of the workpiece, but according to the present invention, it is possible to The cooling gas is passed through a larger jig, increasing the flow rate of the cooling gas and increasing its surface heat transfer coefficient, so this jig can remove a large amount of heat even with a small amount of gas. As the temperature of the workpiece decreases, the heat is absorbed by the jig from the contact area between the workpiece and the jig, so direct heat conduction between solids occurs without using cooling gas as a medium as in the past. This makes it possible to quickly cool down the workpiece.

Furthermore, the cooling device of the present invention has a simpler structure than conventional cooling devices, and has advantages such as lower manufacturing costs.

[Brief explanation of drawings]

FIG. 1 is a schematic structural diagram illustrating pressure welding in a furnace, and FIGS. 2 a, b, and c are schematic structural diagrams illustrating a conventional cooling device. Further, FIGS. 3a and 3b are schematic structural diagrams showing one specific example of the cooling device according to the present invention, and FIG. 4 shows the workpiece and jig portion of another specific example of the cooling device according to the present invention. It is a schematic structural diagram. In the drawing, 21 is a furnace in pressure welding in a furnace, and 22a. 22b, 22a', 22b' are pressure jigs, 23.23
' is the workpiece, 24.24' is the first cooling gas passage, 25
, 25' is a second cooling gas passage, 26 is a gas cooler, 29
31 is a vacuum pump, 32 is a guide plate, 33 is a jig for mounting the workpiece, 34 is a passage formed by the workpiece, 35 is the cooling gas first passage 24
' is a connection port that communicates with the passage 34.

Claims (1)

[Claims] 1. A jig that supports the workpiece is installed inside a furnace in which the workpiece is heat-processed, and a cooling gas passage for cooling the jig and the workpiece is arranged opposite to the workpiece inside the jig. The furnace is equipped with a furnace gas exhaust pipe which is bored in the direction of the furnace and in the direction that intersects with the inside of the furnace so as to communicate with the inside of the furnace, and guides the cooling gas that has been cooled to the outside of the furnace. cooling device.