JP6533697B2 - Vacuum degreasing and sintering furnace - Google Patents

Description

  The present invention relates to a vacuum degreasing and sintering furnace.

  A vacuum degreasing / sintering furnace is a method of heat degreasing a binder consisting of a thermoplastic resin, a forming aid and so on from powder compacts of metals, ceramics etc. (hereinafter referred to as "object to be treated") It is a furnace for obtaining goods. There is a furnace of Patent Document 1 as a conventional vacuum degreasing and sintering furnace.

  In the vacuum degreasing / sintering furnace of Patent Document 1, mounting tables for mounting the products to be processed are provided in multiple stages inside the processing container in which the products to be processed are stored, and a plurality of processing targets are mounted on the mounting tables of each stage. The goods are arranged side by side. At the top of the processing container, one gas supply hole for sweep gas supplied to remove the binder sublimed by heating (hereinafter referred to as "sublimation binder") is provided. On the other hand, at the lower part of the processing container, one gas exhaust hole for exhausting the sweep gas is provided. In the vacuum degreasing / sintering furnace of Patent Document 1, the sweep gas supplied from the upper portion of the processing container flows sequentially to the mounting table of each stage, and is exhausted from the lower portion of the processing container.

  Moreover, as a sintering furnace provided with a multistage-type mounting base, there are also furnaces described in Patent Document 2 and Patent Document 3. In these furnaces, gas supply holes are formed in each stage of the mounting table, and the flow paths of the sweep gas in each stage are structured independently.

Japanese Patent Application Laid-Open No. 11-257869 JP-A-6-147762 JP 2012-13256 A

  In the sintering furnace, it is necessary to remove the sublimation binder as quickly as possible and to uniformly remove the sublimation binder on the stage of each stage. However, as in Patent Document 1, when the sweep gas sequentially flows from the upper stage to the lower stage, the flow velocity and pressure of the gas in the lower stage become smaller than those in the upper stage. For this reason, it was not possible to uniformly degrease the product to be treated. In addition, degreasing defects may occur in the lower-stage product to be treated.

  If uniform degreasing treatment can not be performed, in the sintering step of the next step, the product size variation and the carbon amount variation, etc. of the sintered product occur between the workpiece in the upper stage of the processing vessel and the workpiece in the lower stage. As a result, quality variations occur in sintered products in the same lot.

  Further, as in Patent Document 2 and Patent Document 3, even if the sweep gas is supplied to the mounting table of each stage, the gas can be uniformly flowed into the gas supply holes respectively provided in each stage. As a result, it was not possible to degrease the product uniformly.

  The present invention has been made in view of the above circumstances, and has as its object to reduce variation in quality of a sintered product by uniformly degreasing the product to be treated.

The present invention for solving the above problems is a vacuum degreasing and sintering furnace for degreasing and sintering an object to be treated, which is a processing container in which the object to be treated is accommodated, and a mounting table on which the object to be treated is placed. And a gas supply pipe connected to the processing container, wherein the mounting table is provided in multiple stages in the processing container, and the processing container is provided with a gas supply unit to which a sweep gas is supplied; And the gas supply unit includes a gas introduction space to which the gas supply pipe is connected, and gas supply holes respectively provided in the respective stages of the mounting table, the said gas introduction space, gas distribution member for receiving said sweep gas supplied from the gas supply pipe is disposed, the gas distribution member have a plurality of gas passage openings, wherein the sweep gas passes, the gas The exhaust unit is the exhaust side end of the processing container body A plurality of gas exhaust ports through which the sweep gas passes, and the gas exhaust ports correspond to the respective stages of the mounting table. It is characterized in that it is provided at each height .

  In the vacuum degreasing and sintering furnace according to the present invention, a gas dispersion member for receiving the sweep gas introduced into the processing container is provided on the upstream side of the gas supply holes provided in each stage of the mounting table. For this reason, it is possible to prevent the sweep gas in a state of high gas pressure near the gas supply pipe from being supplied to each gas supply hole while the gas pressure is high. Thereby, the gas pressure in each gas supply hole can be made uniform, and the gas can be uniformly supplied to the mounting table of each stage.

  According to the present invention, the sweep gas can be uniformly supplied to the mounting table of each stage. Thereby, it becomes possible to degrease uniformly a to-be-processed product, and it can reduce the quality variation of a sintered product.

BRIEF DESCRIPTION OF THE DRAWINGS It is a longitudinal cross-sectional view which shows schematic structure of the vacuum degreasing-sintering furnace which concerns on one Embodiment of this invention. It is a longitudinal cross-sectional view which shows schematic structure of a processing container. It is a figure which shows the shape of a gas dispersion | distribution board. It is a front view which shows the attachment structure of a processing container and an attachment or detachment door. It is a side view which shows the attachment structure of a processing container and an attachment or detachment door. It is a top view which shows the attachment structure of a processing container and an attachment or detachment door. It is AA sectional drawing in FIG. The tilt bracket is not shown. It is a front view showing the outline shape of an inclination bracket. It is a side view showing the outline shape of an inclination bracket. It is a top view which shows the general | schematic shape of an inclination bracket.

  Hereinafter, embodiments according to the present invention will be described with reference to the drawings. In the present specification and the drawings, elements having substantially the same functional configuration will be assigned the same reference numerals and redundant description will be omitted.

  As shown in FIG. 1, the vacuum degreasing / sintering furnace 1 according to the present embodiment includes a processing container 20 in which an article to be processed is accommodated, a heater 2 provided to cover the periphery of the processing container 20, and a heater 2. And a vacuum chamber 4 provided so as to cover the non-air-permeable insulation 3. The vacuum chamber 4 includes a front door 4a and a rear door 4b, and the doors 4a and 4b are configured to be openable and closable.

  As shown in FIG. 2, in the interior of the processing container 20, mounting tables 21 on which a plurality of objects to be processed P are mounted are provided in multiple stages, and the objects to be processed P are arranged side by side on the mounting tables 21 of each stage. ing. Further, as shown in FIG. 1, a rail 5 for sliding the processing container 20 at the time of replacing the product P is provided at the lower part of the processing container 20. The rail 5 is supported by a support 6 provided to penetrate the non-air-permeable heat insulating material 3, and the lower end of the support 6 is fixed to the vacuum chamber 4.

  As shown in FIGS. 1 and 2, one end of a gas supply pipe 7 for supplying a sweep gas into the processing container is connected to one of the side portions of the processing container 20. The other end of the gas supply pipe 7 is connected to a gas supply source (not shown) outside the vacuum chamber 4.

  As shown in FIG. 1, the gas supply pipe 7 has a straight horizontal portion 7 a formed so as to extend along the longitudinal direction of the processing container 20 between the heater 2 and the processing container 20. . The sweep gas supplied from the gas supply source is heated by the heater 2 while flowing through the horizontal portion 7a, and when the sweep gas is supplied to the processing container 20, the sweep gas is sufficiently preheated It becomes. As described above, by providing the gas supply pipe 7 so as to take a long distance to the connection end with the processing container 20 without directly connecting the gas supply pipe 7 connected to the vacuum chamber 4 to the processing container 20, The temperature drop on the gas supply side of the processing container 20 can be suppressed. As a result, the temperature of the processing container 20 can be easily maintained at a uniform temperature, and the variation in quality of the article P can be further suppressed.

  As shown in FIG. 2, in the gas supply unit 30 of the processing container 20 to which the gas supply pipe 7 is connected, a gas introduction space S into which the sweep gas from the gas supply pipe 7 is introduced, a gas introduction space S, and a target A partition plate 31 is provided to partition the space where the processed product P is placed. A plurality of gas supply holes 31 a are formed in the partition plate 31 so that the sweep gas of the gas introduction space S flows into the mounting table 21 of each stage. Each gas supply hole 31 a is provided in each stage of the mounting table 21 in accordance with the height of the mounting table 21. In addition, each gas supply hole 31a which concerns on this embodiment is respectively arrange | positioned by the same shape and the same space | interval, and the number of objects of the gas supply hole 31a formed in 1 step is also equal.

  In the gas introduction space S, a gas dispersion plate 32 which receives the sweep gas supplied from the gas supply pipe 7 is disposed. The gas dispersion plate 32 is provided such that the surface R for receiving the sweep gas is perpendicular to the gas introduction direction I. That is, in the gas dispersion plate 32, the pipe axis of the gas supply pipe 7 at the connection portion with the processing vessel 20 and the surface R for receiving the sweep gas are perpendicular. Further, the vertical and horizontal lengths of the gas dispersion plate 32 correspond to the size of the processing container 20, and as shown in FIG. 2, the gas dispersion plate 32 sweeps between the gas dispersion plate 32 and the inner surface of the processing container 20. It is being fixed to processing container 20 so that the crevice which gas passes may be formed.

  As shown in FIG. 3, the gas dispersion plate 32 is formed with a plurality of gas passage ports 32 a through which the sweep gas passes. Although each gas passage port 32a is illustrated with the same shape and the same interval in FIG. 3, the distance from the gas supply pipe 7, the supply flow rate of the gas, the type of gas, the gas dispersion plate 32, and the inner surface of the processing vessel are in fact The hole diameter, the number, the arrangement, and the like are determined so that the gas pressure in each gas supply hole 31a of the partition plate 31 becomes uniform according to the gas supply condition such as a gap formed between the two.

  As shown in FIGS. 2 and 4 to 6, the gas exhaust unit 40 of the processing container 20 is provided with a detachable mounting and demounting door 41, and the mounting and demounting door 41 covers the exhaust side end of the processing container main body 20 a. It is provided as. A plurality of gas exhaust holes 41 a through which the sweep gas passes are formed in the mounting and demounting door 41, and each gas exhaust hole 41 a is provided at a height corresponding to each stage of the mounting table 21. As a result, since the gas supply holes 31a and the gas exhaust holes 41a are formed in the mounting table 21 one by one, independent gas flow paths are formed in the respective stages of the mounting table 21. . In addition, each gas exhaust hole 41a which concerns on this embodiment is respectively arrange | positioned by the same shape and the same space | interval, and the number of objects of the gas exhaust hole 41a formed in 1 step is also equal.

  The mounting and demounting door 41 is attached to the processing container main body 20a by an inclined bracket 42 having an inclined portion. As shown in FIGS. 5 to 7, inclined holes 41 b fitted to the inclined brackets 42 are formed in the attaching / detaching door 41, and two inclined holes 41 b are provided at the end portion in the width direction of the processing container 20. It is done. The inclined hole 41 b is formed so that the height of the hole position decreases from the surface on the vacuum chamber side of the mounting and demounting door 41 toward the surface on the processing container main body side. Further, handles 43 which can be held by the operator are provided at the upper central portion and the lower central portion of the mounting and demounting door 41.

  As shown in FIGS. 8 to 10, the inclined bracket 42 has a bracket attachment portion 42a in surface contact with the processing container main body 20a and an inclined hole fitting provided to project obliquely upward from the side surface of the bracket attachment portion 42a. And a portion 42b. The bracket attachment portion 42a and the inclined hole fitting portion 42b are formed on the same plane. Four bolt holes are formed in the bracket attachment portion 42a, and the bracket attachment portion 42a is bolted to the processing container body 20a. When the inclined bracket 42 is attached to the processing container body 20a, only the inclined hole fitting portion 42b of the inclined bracket 42 protrudes from the exhaust side end of the processing container body 20a.

  When the inclined hole fitting portion 42b in such a state is fitted to the inclined hole 41b of the mounting and demounting door 41, the mounting and demounting door 41 is directed toward the processing container main body 20a along the shape of the mounting portion 42b by its own weight. Move. Thus, the mounting and demounting door 41 is in close contact with the end surface of the processing container body 20a.

  As shown in FIG. 1, an opening 9 through which the sweep gas passes is formed at the bottom of the non-air-permeable heat insulating material 3. Further, one end of a gas exhaust pipe 11 for suctioning sweep gas in the vacuum chamber is attached to the upper portion of the vacuum chamber 4. The other end of the gas exhaust pipe 11 is connected to a vacuum pump (not shown). The sweep gas supplied from the gas supply pipe 7 is exhausted out of the system through the processing vessel 20, the opening 9 of the non-air-permeable heat insulating material 3 and the gas exhaust pipe 11 as indicated by the arrows in FIG. Ru.

  The vacuum degreasing and sintering furnace 1 according to the present embodiment is configured as described above.

  When the sweep gas is supplied to the processing container 20 of the vacuum degreasing and sintering furnace 1 as described above, the sweep gas introduced into the processing container 20 strikes the gas dispersion plate 32, and thereafter, from the central portion to the peripheral portion of the gas dispersion plate 32. It will flow toward you. As described above, once the sweep gas introduced into the processing vessel 20 is received by the gas dispersion plate 32, the sweep gas near the gas supply pipe in the state of high gas pressure is as it is to each gas supply hole 31a. It will not flow.

  On the other hand, just by receiving the introduced sweep gas as a flat plate, the sweep gas flowing from the central portion to the peripheral portion will pass between the flat plate and the inner surface of the processing vessel 20, and the gas pressure at the peripheral portion of the flat plate Becomes high. However, a plurality of gas passage ports 32a through which the sweep gas passes are formed in the dispersion plate according to the present embodiment. For this reason, a part of the sweep gas received by the gas dispersion plate 32 travels to the gas supply hole 31 a provided in the partition plate 31 through the gas passage port 32 a. This suppresses the increase in gas pressure at the peripheral portion of the gas dispersion plate 32.

  Each gas passage port 32 a formed in the gas dispersion plate 32 includes the distance from the gas supply pipe 7, the gas supply flow rate, the type of gas, the size of the gas dispersion plate 32, the gas dispersion plate 32 and the processing vessel 20. The number of holes, the hole diameter, the shape, and the arrangement so that the gas pressure becomes uniform behind the gas dispersion plate 32 (downstream side of the gas) according to the gas supply conditions such as a gap formed with the inner surface Etc. are defined. For this reason, the gas pressure behind the gas dispersion plate 32 can be made uniform, and the gas pressure in each gas supply hole 31a can also be made uniform. As a result, the sweep gas can be uniformly introduced into the mounting table 21 of each stage.

  That is, according to the vacuum degreasing and sintering furnace 1 according to the present embodiment, the gas dispersion plate 32 in which the plurality of gas passage ports 32 a are formed is provided in the gas introduction space S of the processing container 20. The sweep gas can be uniformly supplied to the gas supply holes 31a. Thereby, the pressure variation of the sweep gas flowing through the mounting table 21 of each stage can be suppressed, and the degreasing variation of the workpiece P can be reduced.

  Although the preferred embodiments of the present invention have been described above, the present invention is not limited to such examples. It is apparent that those skilled in the art can conceive of various changes or modifications within the scope of the technical idea described in the claims, and the technical scope of the present invention is also natural for them. It is understood to belong to

  For example, in the above embodiment, the gas dispersion plate 32 is provided perpendicular to the gas introduction direction I, but the angle between the surface R for receiving the sweep gas of the gas dispersion plate 32 and the gas introduction direction I is not perpendicular. Also good. The angle of the gas dispersion plate 32 can be appropriately changed according to the shapes of the processing container 20 and the mounting table 21, the position of the gas supply pipe 7, the shape, number, and arrangement of the gas supply holes 31 a. That is, if the gas dispersion plate 32 is provided to receive the sweep gas introduced into the processing vessel 20 once, the sweep gas introduced into the processing vessel 20 is supplied to the gas supply hole 31a while the gas pressure is high. It can not be done.

  Further, the shape of the gas dispersion plate 32 is not limited to a plate-like member. In order to obtain the effects according to the present invention, any member having a surface R for receiving the sweep gas supplied from the gas supply pipe 7 and capable of dispersing the sweep gas in each gas supply hole 31a may be used.

  In the above embodiment, the mounting and demounting door 41 is closely attached to the processing container body 20a by its own weight using the inclined bracket 42. However, even if the mounting and demounting door 41 uses its own weight without using the inclination bracket 42. good.

  Further, in the gas exhaust unit 40 of the processing container 20, instead of the detachable door 41, an openable door may be used. The pressure of the sweep gas flowing into the mounting table 21 of each stage is reduced due to pressure loss or the like due to contact with the workpiece P on the mounting table. For this reason, when the number of objects to be processed P mounted on the mounting table 21 is different in each stage, the sweep gas can be used even if the gas pressure in each gas supply hole 31a of the gas supply unit 30 is uniform. While flowing through the mounting table 21 of each stage, a pressure difference occurs.

  On the other hand, in the configuration using the mounting and demounting door 41 as described in the above embodiment, the mounting and demounting door 41 attached to the processing container 20 is a gas exhaust hole 41a suitable for the above-described arrangement of the article P. Can be easily replaced with other removable doors. As a result, even when the number of workpieces P placed on the mounting table 21 is different in each stage, the sweep gas can be uniformly supplied to each stage. That is, when the detachable door 41 is used, it is possible to easily cope with processing lots in which the shape, the number, and the like of the workpieces P are different. As a result, the sweep gas can be supplied uniformly to each stage, and the time to start processing of the next lot can be shortened.

  Further, in the gas supply pipe 7 of the above embodiment, the straight horizontal portion 7a is disposed between the heater 2 and the processing vessel 20, and the sweep gas is preheated by the horizontal portion 7a. However, the gas is preheated. The shape of the preheating section of the gas supply pipe 7 for the purpose may not be linear. For example, the shape of the preheating section may be a shape that meanders in the width direction of the processing container 20. That is, if the gas supply pipe 7 is provided so as to have a preheating section between the heater 2 and the processing vessel 20, it is possible to obtain an effect that the temperature of the processing vessel 20 can be easily kept uniform.

  The present invention can be applied to a vacuum degreasing and sintering furnace.

DESCRIPTION OF SYMBOLS 1 vacuum degreasing and sintering furnace 2 heater 3 non-air-permeable heat insulating material 4 vacuum chamber 4 a front door 4 b back door 5 rail 6 support 7 gas supply pipe 7 a gas supply pipe horizontal portion 9 opening 11 gas exhaust pipe 20 processing container 20 a processing container Main body 21 Mounting table 30 Gas supply unit 31 Partition plate 31a Gas supply hole 32 Gas distribution plate 32a Gas passage port 40 Gas exhaust unit 41 Detachable door 41a Gas exhaust hole 41b Inclined hole 42 Inclined bracket 42a Bracket attachment part 42b Inclined hole fitting part 43 Handle I Gas introduction direction P Processed item R Surface to receive sweep gas S Gas introduction space

Claims (3)

A vacuum degreasing and sintering furnace for degreasing and sintering an object to be treated,
A processing container in which an object to be processed is accommodated;
A mounting table on which the product to be processed is placed;
And a gas supply pipe connected to the processing vessel,
The mounting table is provided in multiple stages in the processing container,
The processing container is
A gas supply unit to which a sweep gas is supplied;
And a gas exhaust unit for exhausting the sweep gas.
The gas supply unit
A gas introduction space to which the gas supply pipe is connected;
And gas supply holes respectively provided in the respective stages of the mounting table;
In the gas introduction space, a gas dispersion member for receiving the sweep gas supplied from the gas supply pipe is disposed,
The gas distribution member have a plurality of gas passage openings, wherein the sweep gas passes,
The gas exhaust unit includes a removable door that is provided to cover the exhaust side end of the processing container body.
A plurality of gas exhaust ports through which the sweep gas passes are formed in the mounting and demounting door,
The vacuum degreasing and sintering furnace, wherein the gas exhaust port is provided at a height corresponding to each stage of the mounting table . The vacuum degreasing / sintering furnace according to claim 1 , wherein the mounting / demounting door is configured to be in close contact with the processing container body by its own weight. An inclination bracket is attached to the processing vessel body,
An inclined hole fitted to the inclined bracket is formed in the mounting and demounting door,
The inclined bracket is
A bracket mounting portion that makes surface contact with the processing container body;
And an inclined hole fitting portion projecting obliquely upward from the bracket mounting portion,
Wherein the inclined hole fitting portion and the bracket mounting portion is formed on the same plane, vacuum degreasing sintering furnace according to claim 1 or 2.

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