WO2011081081A1 - Degreasing method - Google Patents
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- WO2011081081A1 WO2011081081A1 PCT/JP2010/073276 JP2010073276W WO2011081081A1 WO 2011081081 A1 WO2011081081 A1 WO 2011081081A1 JP 2010073276 W JP2010073276 W JP 2010073276W WO 2011081081 A1 WO2011081081 A1 WO 2011081081A1
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- C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
- C04B35/622—Forming processes; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
- C04B35/626—Preparing or treating the powders individually or as batches ; preparing or treating macroscopic reinforcing agents for ceramic products, e.g. fibres; mechanical aspects section B
- C04B35/63—Preparing or treating the powders individually or as batches ; preparing or treating macroscopic reinforcing agents for ceramic products, e.g. fibres; mechanical aspects section B using additives specially adapted for forming the products, e.g.. binder binders
- C04B35/638—Removal thereof
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- B22F3/00—Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces
- B22F3/10—Sintering only
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- B22F3/00—Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces
- B22F3/10—Sintering only
- B22F3/1017—Multiple heating or additional steps
- B22F3/1021—Removal of binder or filler
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- C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
- C04B35/622—Forming processes; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
- C04B35/626—Preparing or treating the powders individually or as batches ; preparing or treating macroscopic reinforcing agents for ceramic products, e.g. fibres; mechanical aspects section B
- C04B35/63—Preparing or treating the powders individually or as batches ; preparing or treating macroscopic reinforcing agents for ceramic products, e.g. fibres; mechanical aspects section B using additives specially adapted for forming the products, e.g.. binder binders
- C04B35/632—Organic additives
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- C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
- C04B2235/65—Aspects relating to heat treatments of ceramic bodies such as green ceramics or pre-sintered ceramics, e.g. burning, sintering or melting processes
- C04B2235/656—Aspects relating to heat treatments of ceramic bodies such as green ceramics or pre-sintered ceramics, e.g. burning, sintering or melting processes characterised by specific heating conditions during heat treatment
- C04B2235/6562—Heating rate
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- C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
- C04B2235/65—Aspects relating to heat treatments of ceramic bodies such as green ceramics or pre-sintered ceramics, e.g. burning, sintering or melting processes
- C04B2235/656—Aspects relating to heat treatments of ceramic bodies such as green ceramics or pre-sintered ceramics, e.g. burning, sintering or melting processes characterised by specific heating conditions during heat treatment
- C04B2235/6565—Cooling rate
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- C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
- C04B2235/65—Aspects relating to heat treatments of ceramic bodies such as green ceramics or pre-sintered ceramics, e.g. burning, sintering or melting processes
- C04B2235/656—Aspects relating to heat treatments of ceramic bodies such as green ceramics or pre-sintered ceramics, e.g. burning, sintering or melting processes characterised by specific heating conditions during heat treatment
- C04B2235/6567—Treatment time
Definitions
- the present invention relates to a degreasing method.
- the present invention claims priority based on Japanese Patent Application No. 2009-297251 filed in Japan on December 28, 2009, the contents of which are incorporated herein by reference.
- the degreasing method according to the above (1) may have an adjustment step of adjusting the time of the holding step based on the evaporation characteristics of the organic binder.
- the temperature between the powder molded products is made substantially uniform, and then the temperature is raised to the temperature in the holding step. Therefore, even when the temperature difference between the temperature in the holding step and the evaporation temperature of the organic binder is relatively large, the organic binder is uniformly defatted between the powder molded products, and the gas generated by evaporation of the organic binder. It is possible to suppress the occurrence of carburization of the powder molded product due to.
- step S3 the wax is reliably evaporated from the processed product W by setting the temperature in the furnace to a temperature higher than the evaporation point Tv of the wax. If the temperature in the furnace is raised to the evaporation point Tv of the wax, the wax usually evaporates. However, if the temperature in the furnace is maintained at the evaporation point Tv due to differences in wax solids or differences in temperature rise between the processed products W, a portion where the wax evaporates and a portion where the wax does not evaporate are generated. For this reason, in this embodiment, the wax is reliably evaporated by maintaining the temperature in the furnace at a temperature higher than the evaporation point Tv in step S3.
- step S3 generation
- the carburizing temperature of the processed product W is determined by the type of wax and the pressure in the furnace.
- the carburizing temperature of the processed product W of this embodiment is, for example, about 50 ° C. higher than the evaporation point Tv.
- the keep temperature T2 is higher than the evaporation point Tv.
- the wax may not evaporate. There is.
- the first embodiment described above is a degreasing method for heating and degreasing the wax contained in the processed product W1 and the processed product W2 (powder molded product) arranged at different positions in the furnace.
- a step S3 holding step in which the temperature in the furnace is held for a predetermined time within a range higher than the evaporation point Tv at which the wax evaporates and lower than the temperature at which the processed product W is carburized.
- this step S3 by maintaining the temperature in the furnace for a predetermined time, the expansion of the temperature difference between the processed products W or different parts of one processed product W can be suppressed, and the processed product W can be transmitted by heat conduction in the furnace.
- the first measurement step of measuring the temperature at the first position of a different part of the processed product W and the first position of the processed product W are: And a second measuring step for measuring the temperature at a different second position. And before the measurement result in a 1st measurement process and a 2nd measurement process reaches evaporation temperature, it has the 2nd holding process which hold
- FIG. 3 is a graph for explaining a degreasing method according to the second embodiment of the present invention. Similar to the above embodiment, in the graph of FIG. 3, the vertical axis represents temperature and the horizontal axis represents time. In FIG. 3, the solid line indicates the temperature change in the furnace (heater 5), the broken line indicates the temperature change of the processed product W1, and the alternate long and short dash line indicates the temperature change of the processed product W2.
- the evaporation point Tv of the wax of the second embodiment is about 350 ° C.
- the amount of heat input to the processed product W can be increased in step S1 and step S2.
- the time for raising the temperature of the processed product W to the sintering temperature T1 in steps S4 and S5 is shortened.
- the total processing time in this embodiment is 8.5 hours.
- the pressure adjustment step is provided, the atmospheric pressure in the furnace is increased and the heat transfer to the processed product W is increased. Time can be shortened.
- FIG. 4 is a graph for explaining a degreasing method according to the third embodiment of the present invention. Similar to the above embodiment, in the graph of FIG. 4, the vertical axis represents temperature and the horizontal axis represents time. In FIG. 4, the solid line indicates the temperature change in the furnace (heater 5), the broken line indicates the temperature change of the processed product W1, and the alternate long and short dash line indicates the temperature change of the processed product W2.
- step S1 proceeds from step S1 to step S3 through step S2, but the present invention is not limited to this.
- the process proceeds from step S1 to step S3 without passing through step S2.
- the wax is exemplified as the organic binder contained in the powder molded product.
- the present invention is not limited to this, and other types of organic binders such as a binder may be used. May be.
- the degreasing method of the present invention it is possible to reduce the quality variation of each product of the powder molded product and the quality variation of each part of one product, and the processing time of the powder molded product can be shortened.
Abstract
Disclosed is a degreasing method for removing wax in one or a plurality of treated articles by heating in a furnace, which involves a step for maintaining the temperature in the abovementioned furnace for a prescribed period of time within a temperature range that is higher than the vaporization point of the wax and lower than the temperature at which the treated articles carburize, thereby being able to reduce variations in the quality of each treated article.
Description
本発明は、脱脂方法に関する。
本発明は、２００９年１２月２８日に、日本に出願された特願２００９－２９７２５１号に基づき優先権を主張し、その内容をここに援用する。 The present invention relates to a degreasing method.
The present invention claims priority based on Japanese Patent Application No. 2009-297251 filed in Japan on December 28, 2009, the contents of which are incorporated herein by reference.
本発明は、２００９年１２月２８日に、日本に出願された特願２００９－２９７２５１号に基づき優先権を主張し、その内容をここに援用する。 The present invention relates to a degreasing method.
The present invention claims priority based on Japanese Patent Application No. 2009-297251 filed in Japan on December 28, 2009, the contents of which are incorporated herein by reference.
焼結処理においては、粉末原料にワックス、バインダー等の有機結合剤を混練して所定形状に成型した粉末成型品を加熱することにより、その粉末成型品に含まれるバインダーを除去し（脱脂処理）、その後、更に炉内温度を上げて焼結させ、最終製品を得る。この焼結処理を実施する加熱炉としては、例えば下記特許文献１に記載の脱脂焼結炉が挙げられる。
In the sintering treatment, the binder contained in the powder molded product is removed by heating the powder molded product obtained by kneading an organic binder such as wax and binder into the powder raw material and molding it into a predetermined shape (degreasing treatment). Thereafter, the temperature in the furnace is further raised and sintered to obtain a final product. As a heating furnace for performing this sintering treatment, for example, a degreasing sintering furnace described in Patent Document 1 below can be cited.
ところで、この種の粉末成型品は小物大量処理が行われることが多く、棚構造からなる内箱に配列、収容して炉内に装入されるのが通例であることは、特許文献１に記載の通りである。粉末成型品の均質化を図るためには、全ての粉末成型品の温度を同程度に昇温させて脱脂処理する必要があるが、炉内における配置位置、例えば、ヒーターに対する位置の違いで内箱の外側と中心側の温度差が生まれて、粉末成型品間において温度差が生じてしまう。粉末成型品間において温度差が生じると、脱脂が終了する時間が異なって製品の浸炭の程度が変化し、品質のバラツキが生じる。なお、粉末成型品間における温度差を低減させるために、炉内の温度を緩やかに昇温させる手法があるが、脱脂処理開始までに長時間を要するため非効率である。
また、この製品間のバラツキだけではなく、大型の粉末成型品を１つだけを脱脂処理する場合であっても、この粉末成型品の部分ごとに温度差が生じれば、同様に部分ごとに品質のバラツキが生ずる。 By the way, this kind of powder molded product is often subjected to mass processing of small items, and it is customary to arrange and store it in an inner box made up of a shelf structure and insert it into a furnace. As described. In order to homogenize the powder molded products, it is necessary to raise the temperature of all the powder molded products to the same level and to degrease them, but depending on the position in the furnace, for example, the position relative to the heater A temperature difference between the outer side and the center side of the box is created, and a temperature difference occurs between the powder molded products. When a temperature difference occurs between the powder molded products, the time for degreasing is different, the degree of carburization of the product is changed, and quality variation occurs. In order to reduce the temperature difference between the powder molded products, there is a method of gradually increasing the temperature in the furnace, but this is inefficient because it takes a long time to start the degreasing process.
Moreover, not only the variation between these products, but also when only one large powder molded product is degreased, if there is a temperature difference for each part of this powder molded product, the same Variation in quality occurs.
また、この製品間のバラツキだけではなく、大型の粉末成型品を１つだけを脱脂処理する場合であっても、この粉末成型品の部分ごとに温度差が生じれば、同様に部分ごとに品質のバラツキが生ずる。 By the way, this kind of powder molded product is often subjected to mass processing of small items, and it is customary to arrange and store it in an inner box made up of a shelf structure and insert it into a furnace. As described. In order to homogenize the powder molded products, it is necessary to raise the temperature of all the powder molded products to the same level and to degrease them, but depending on the position in the furnace, for example, the position relative to the heater A temperature difference between the outer side and the center side of the box is created, and a temperature difference occurs between the powder molded products. When a temperature difference occurs between the powder molded products, the time for degreasing is different, the degree of carburization of the product is changed, and quality variation occurs. In order to reduce the temperature difference between the powder molded products, there is a method of gradually increasing the temperature in the furnace, but this is inefficient because it takes a long time to start the degreasing process.
Moreover, not only the variation between these products, but also when only one large powder molded product is degreased, if there is a temperature difference for each part of this powder molded product, the same Variation in quality occurs.
本発明は、上記問題点に鑑みてなされたものであり、製品毎の品質のバラツキおよび一製品の各部分の品質のバラツキを低減できる粉末成型品の脱脂方法の提供を目的とする。また、第２の目的として、本発明は、処理時間を短縮できる脱脂方法の提供を目的とする。
The present invention has been made in view of the above problems, and an object of the present invention is to provide a powdered product degreasing method capable of reducing the quality variation of each product and the quality variation of each part of one product. Moreover, as a second object, the present invention aims to provide a degreasing method capable of shortening the processing time.
上記の課題を解決するために、本発明では、以下の手法を採用する。即ち、
（１）本発明は、炉内において一又は複数の粉末成型品に含まれる有機結合剤を、加熱して脱脂する脱脂方法であって、上記炉内の温度を、上記有機結合剤が蒸発する蒸発温度より高く、上記粉末成型品が浸炭する温度より低い範囲内で所定時間保持する保持工程を有する。
本発明では、保持工程において、炉内の温度を、所定時間保持することで、粉末成型品間あるいは一つの粉末成型品の部分間の温度差の拡大が抑えられると共に、炉内における熱伝導により該温度差が緩和される。また、保持工程において、炉内の温度を、有機結合剤の蒸発温度より高い温度とすることにより粉末成型品から有機結合剤を確実に蒸発させることができ、且つ、有機結合剤が蒸発して発生したガスによる浸炭が起こる温度より低い温度とすることで、粉末成型品の浸炭の発生を抑制できる。 In order to solve the above problems, the present invention employs the following technique. That is,
(1) The present invention is a degreasing method for heating and degreasing an organic binder contained in one or a plurality of powder molded products in a furnace, and the organic binder evaporates at a temperature in the furnace. It has a holding step of holding for a predetermined time within a range higher than the evaporation temperature and lower than the temperature at which the powder molded product is carburized.
In the present invention, in the holding step, the temperature in the furnace is held for a predetermined time, so that an increase in temperature difference between powder molded products or parts of one powder molded product can be suppressed, and heat conduction in the furnace. The temperature difference is relaxed. Further, in the holding step, by setting the temperature in the furnace to a temperature higher than the evaporation temperature of the organic binder, the organic binder can be reliably evaporated from the powder molded product, and the organic binder is evaporated. By setting the temperature lower than the temperature at which carburization by the generated gas occurs, the occurrence of carburization of the powder molded product can be suppressed.
（１）本発明は、炉内において一又は複数の粉末成型品に含まれる有機結合剤を、加熱して脱脂する脱脂方法であって、上記炉内の温度を、上記有機結合剤が蒸発する蒸発温度より高く、上記粉末成型品が浸炭する温度より低い範囲内で所定時間保持する保持工程を有する。
本発明では、保持工程において、炉内の温度を、所定時間保持することで、粉末成型品間あるいは一つの粉末成型品の部分間の温度差の拡大が抑えられると共に、炉内における熱伝導により該温度差が緩和される。また、保持工程において、炉内の温度を、有機結合剤の蒸発温度より高い温度とすることにより粉末成型品から有機結合剤を確実に蒸発させることができ、且つ、有機結合剤が蒸発して発生したガスによる浸炭が起こる温度より低い温度とすることで、粉末成型品の浸炭の発生を抑制できる。 In order to solve the above problems, the present invention employs the following technique. That is,
(1) The present invention is a degreasing method for heating and degreasing an organic binder contained in one or a plurality of powder molded products in a furnace, and the organic binder evaporates at a temperature in the furnace. It has a holding step of holding for a predetermined time within a range higher than the evaporation temperature and lower than the temperature at which the powder molded product is carburized.
In the present invention, in the holding step, the temperature in the furnace is held for a predetermined time, so that an increase in temperature difference between powder molded products or parts of one powder molded product can be suppressed, and heat conduction in the furnace. The temperature difference is relaxed. Further, in the holding step, by setting the temperature in the furnace to a temperature higher than the evaporation temperature of the organic binder, the organic binder can be reliably evaporated from the powder molded product, and the organic binder is evaporated. By setting the temperature lower than the temperature at which carburization by the generated gas occurs, the occurrence of carburization of the powder molded product can be suppressed.
（２）上記（１）に記載の脱脂方法は、上記有機結合剤の蒸発特性に基づいて、上記保持工程の時間を調節する調節工程を有してもよい。
この手法を採用することによって、本発明では、有機結合剤の固体差や、粉末成型品間の昇温速度の違いに対応でき、粉末成型品間において均一な脱脂を実現できる。 (2) The degreasing method according to the above (1) may have an adjustment step of adjusting the time of the holding step based on the evaporation characteristics of the organic binder.
By adopting this method, in the present invention, it is possible to cope with a difference in organic binder solids and a difference in temperature increase rate between powder molded products, and uniform degreasing between powder molded products can be realized.
この手法を採用することによって、本発明では、有機結合剤の固体差や、粉末成型品間の昇温速度の違いに対応でき、粉末成型品間において均一な脱脂を実現できる。 (2) The degreasing method according to the above (1) may have an adjustment step of adjusting the time of the holding step based on the evaporation characteristics of the organic binder.
By adopting this method, in the present invention, it is possible to cope with a difference in organic binder solids and a difference in temperature increase rate between powder molded products, and uniform degreasing between powder molded products can be realized.
（３）上記（１）または（２）に記載の脱脂方法は、上記炉内には、少なくとも互いに異なる位置に第１の粉末成型品及び第２の粉末成型品が配置されており、上記第１の粉末成型品の温度を計測する第１計測工程と、上記第２の粉末成型品の温度を計測する第２計測工程とを有し、上記第１計測工程及び上記第２計測工程での計測結果が共に上記蒸発温度に達する前に、上記炉内の温度を、上記蒸発温度において所定時間保持する第２保持工程を有してもよい。
この手法を採用することによって、本発明では、第１の粉末成型品及び第２の粉末成型品が共に有機結合剤の蒸発温度になるまでの間、炉内の温度をその有機結合剤の蒸発温度で保持することにより、粉末成型品間の温度を略均一にした後に、保持工程での温度への昇温が開始できる状態にする。このため、保持工程での温度と有機結合剤の蒸発温度との温度差が比較的大きい場合でも、粉末成型品間において有機結合剤が均一に脱脂され、有機結合剤が蒸発して発生したガスによる粉末成型品の浸炭の発生を抑制できる。 (3) In the degreasing method described in the above (1) or (2), the first powder molded product and the second powder molded product are arranged at least in different positions in the furnace, and the first A first measurement step for measuring the temperature of the first powder molded product, and a second measurement step for measuring the temperature of the second powder molded product, wherein the first measurement step and the second measurement step You may have the 2nd holding | maintenance process which hold | maintains the temperature in the said furnace at the said evaporation temperature for a predetermined period, before both measurement results reach the said evaporation temperature.
By adopting this method, in the present invention, the temperature in the furnace is set to evaporate the organic binder until both the first powder molded product and the second powder molded product reach the evaporation temperature of the organic binder. By maintaining the temperature, the temperature between the powder molded products is made substantially uniform, and then the temperature is raised to the temperature in the holding step. Therefore, even when the temperature difference between the temperature in the holding step and the evaporation temperature of the organic binder is relatively large, the organic binder is uniformly defatted between the powder molded products, and the gas generated by evaporation of the organic binder. It is possible to suppress the occurrence of carburization of the powder molded product due to.
この手法を採用することによって、本発明では、第１の粉末成型品及び第２の粉末成型品が共に有機結合剤の蒸発温度になるまでの間、炉内の温度をその有機結合剤の蒸発温度で保持することにより、粉末成型品間の温度を略均一にした後に、保持工程での温度への昇温が開始できる状態にする。このため、保持工程での温度と有機結合剤の蒸発温度との温度差が比較的大きい場合でも、粉末成型品間において有機結合剤が均一に脱脂され、有機結合剤が蒸発して発生したガスによる粉末成型品の浸炭の発生を抑制できる。 (3) In the degreasing method described in the above (1) or (2), the first powder molded product and the second powder molded product are arranged at least in different positions in the furnace, and the first A first measurement step for measuring the temperature of the first powder molded product, and a second measurement step for measuring the temperature of the second powder molded product, wherein the first measurement step and the second measurement step You may have the 2nd holding | maintenance process which hold | maintains the temperature in the said furnace at the said evaporation temperature for a predetermined period, before both measurement results reach the said evaporation temperature.
By adopting this method, in the present invention, the temperature in the furnace is set to evaporate the organic binder until both the first powder molded product and the second powder molded product reach the evaporation temperature of the organic binder. By maintaining the temperature, the temperature between the powder molded products is made substantially uniform, and then the temperature is raised to the temperature in the holding step. Therefore, even when the temperature difference between the temperature in the holding step and the evaporation temperature of the organic binder is relatively large, the organic binder is uniformly defatted between the powder molded products, and the gas generated by evaporation of the organic binder. It is possible to suppress the occurrence of carburization of the powder molded product due to.
（４）上記（１）または（２）に記載の脱脂方法は、上記粉末成型品の第１の位置の温度を計測する第１計測工程と、該粉末成型品の上記第１の位置とは異なる第２の位置の温度を計測する第２計測工程とを有し、上記第１計測工程及び上記第２計測工程での計測結果が共に上記蒸発温度に達する前に、上記炉内の温度を、上記蒸発温度において所定時間保持する第２保持工程を有してもよい。
この手法を採用することによって、本発明では、一つの粉末成型品において第１の位置の部分及び第２の位置の部分が共に有機結合剤の蒸発温度になるまでの間、炉内の温度を該蒸発温度で保持することにより、一つの粉末成型品の部分間の温度を略均一にした後に、保持工程での温度への昇温が開始できる状態にする。このため、保持工程での温度と有機結合剤の蒸発温度との温度差が比較的大きい場合でも、一つの粉末成型品の部分間において有機結合剤が均一に脱脂され、有機結合剤が蒸発して発生したガスによる粉末成型品の浸炭の発生を抑制できる。 (4) In the degreasing method according to the above (1) or (2), the first measurement step of measuring the temperature at the first position of the powder molded product and the first position of the powder molded product are A second measurement step for measuring the temperature at a different second position, and before the measurement results in the first measurement step and the second measurement step both reach the evaporation temperature, the temperature in the furnace is A second holding step of holding for a predetermined time at the evaporation temperature may be included.
By adopting this method, in the present invention, the temperature in the furnace is kept until the first position portion and the second position portion are both at the evaporation temperature of the organic binder in one powder molded product. By holding at the evaporation temperature, the temperature between the parts of one powder molded product is made substantially uniform, and then the temperature rise to the temperature in the holding step can be started. For this reason, even when the temperature difference between the temperature in the holding step and the evaporation temperature of the organic binder is relatively large, the organic binder is uniformly degreased between the parts of one powder molded product, and the organic binder evaporates. The carburization of the powder molded product due to the generated gas can be suppressed.
この手法を採用することによって、本発明では、一つの粉末成型品において第１の位置の部分及び第２の位置の部分が共に有機結合剤の蒸発温度になるまでの間、炉内の温度を該蒸発温度で保持することにより、一つの粉末成型品の部分間の温度を略均一にした後に、保持工程での温度への昇温が開始できる状態にする。このため、保持工程での温度と有機結合剤の蒸発温度との温度差が比較的大きい場合でも、一つの粉末成型品の部分間において有機結合剤が均一に脱脂され、有機結合剤が蒸発して発生したガスによる粉末成型品の浸炭の発生を抑制できる。 (4) In the degreasing method according to the above (1) or (2), the first measurement step of measuring the temperature at the first position of the powder molded product and the first position of the powder molded product are A second measurement step for measuring the temperature at a different second position, and before the measurement results in the first measurement step and the second measurement step both reach the evaporation temperature, the temperature in the furnace is A second holding step of holding for a predetermined time at the evaporation temperature may be included.
By adopting this method, in the present invention, the temperature in the furnace is kept until the first position portion and the second position portion are both at the evaporation temperature of the organic binder in one powder molded product. By holding at the evaporation temperature, the temperature between the parts of one powder molded product is made substantially uniform, and then the temperature rise to the temperature in the holding step can be started. For this reason, even when the temperature difference between the temperature in the holding step and the evaporation temperature of the organic binder is relatively large, the organic binder is uniformly degreased between the parts of one powder molded product, and the organic binder evaporates. The carburization of the powder molded product due to the generated gas can be suppressed.
（５）上記（３）または（４）に記載の脱脂方法は、上記第２保持工程に移行する前に、上記炉内の温度を、上記蒸発温度以上に昇温させる昇温工程を有してもよい。
この手法を採用することによって、本発明では、炉内の温度を高めると粉末成型品の昇温速度を早められるため、処理時間の短縮ができる。 (5) The degreasing method according to the above (3) or (4) has a temperature raising step of raising the temperature in the furnace to the evaporation temperature or higher before moving to the second holding step. May be.
By adopting this method, in the present invention, if the temperature in the furnace is increased, the temperature rise rate of the powder molded product can be increased, so that the processing time can be shortened.
この手法を採用することによって、本発明では、炉内の温度を高めると粉末成型品の昇温速度を早められるため、処理時間の短縮ができる。 (5) The degreasing method according to the above (3) or (4) has a temperature raising step of raising the temperature in the furnace to the evaporation temperature or higher before moving to the second holding step. May be.
By adopting this method, in the present invention, if the temperature in the furnace is increased, the temperature rise rate of the powder molded product can be increased, so that the processing time can be shortened.
（６）上記（１）～（５）に記載の脱脂方法は、上記炉内の雰囲気圧力を調節する圧力度調節工程を有してもよい。
この手法を採用することによって、本発明では、炉内の雰囲気圧力を高めると粉末成型品への伝熱性が増すため、処理時間の短縮ができる。 (6) The degreasing method described in the above (1) to (5) may have a pressure degree adjusting step of adjusting the atmospheric pressure in the furnace.
By adopting this method, in the present invention, when the atmospheric pressure in the furnace is increased, the heat transfer to the powder molded product is increased, so that the processing time can be shortened.
この手法を採用することによって、本発明では、炉内の雰囲気圧力を高めると粉末成型品への伝熱性が増すため、処理時間の短縮ができる。 (6) The degreasing method described in the above (1) to (5) may have a pressure degree adjusting step of adjusting the atmospheric pressure in the furnace.
By adopting this method, in the present invention, when the atmospheric pressure in the furnace is increased, the heat transfer to the powder molded product is increased, so that the processing time can be shortened.
本発明は、炉内において一又は複数の粉末成型品に含まれる有機結合剤を、加熱して脱脂する脱脂方法であって、粉末成型品の製品毎の品質のバラツキおよび一製品の各部分の品質のバラツキを低減でき、粉末成型品の処理時間も短縮できる。
The present invention relates to a degreasing method in which an organic binder contained in one or a plurality of powder molded products is heated and degreased in a furnace, the quality variation of each product of the powder molded products, and each part of one product Variations in quality can be reduced, and processing time for powder molded products can be shortened.
以下、本発明の実施形態における脱脂方法について図面を参照して説明する。なお、以下の説明では、粉末原料に混練し、粉末成型品とする有機結合剤に、ワックスを用いた場合を例示して説明する。
Hereinafter, a degreasing method according to an embodiment of the present invention will be described with reference to the drawings. In the following description, a case where wax is used as an organic binder that is kneaded with a powder raw material to form a powder molded product will be described as an example.
図１は、本発明の実施形態における脱脂炉１の構成を示す図である。
脱脂炉１は、減圧・真空雰囲気下でワックス（有機結合剤）を含む粉末成型品である処理品Ｗを加熱することにより、その処理品Ｗに含まれるワックスを除去し（脱脂処理）、その後、更に炉内温度を上げて処理品Ｗを焼結させて製品を得る。脱脂炉１は、炉内の圧力状態が変化した場合であってもその圧力に耐えられるように、略円筒形状に形状設定された真空容器からなる炉体２を有する。炉体２には、不図示の水冷ジャケットが設けられており、炉体２の温度過昇を防止する。 FIG. 1 is a diagram showing a configuration of adegreasing furnace 1 in an embodiment of the present invention.
Thedegreasing furnace 1 removes the wax contained in the processed product W by heating the processed product W that is a powder molded product containing wax (organic binder) in a reduced pressure / vacuum atmosphere (degreasing treatment), and then Further, the temperature in the furnace is raised to sinter the processed product W to obtain a product. The degreasing furnace 1 has a furnace body 2 composed of a vacuum vessel shaped in a substantially cylindrical shape so as to withstand the pressure even when the pressure state in the furnace changes. The furnace body 2 is provided with a water cooling jacket (not shown) to prevent the temperature of the furnace body 2 from rising excessively.
脱脂炉１は、減圧・真空雰囲気下でワックス（有機結合剤）を含む粉末成型品である処理品Ｗを加熱することにより、その処理品Ｗに含まれるワックスを除去し（脱脂処理）、その後、更に炉内温度を上げて処理品Ｗを焼結させて製品を得る。脱脂炉１は、炉内の圧力状態が変化した場合であってもその圧力に耐えられるように、略円筒形状に形状設定された真空容器からなる炉体２を有する。炉体２には、不図示の水冷ジャケットが設けられており、炉体２の温度過昇を防止する。 FIG. 1 is a diagram showing a configuration of a
The
炉体２内には、複数の処理品Ｗを収容する収容棚３と、収容棚３を囲うマッフル４と、マッフル４を介して処理品Ｗを加熱するヒーター５と、マッフル４及びヒーター５を囲う断熱室６とが設けられている。また、炉体２には、炉体２内にキャリアガスを供給するキャリアガス供給系７と、炉内雰囲気圧力をコントロールする主排気系８と、マッフル４内に発生したワックス蒸気を排気する脱脂排気系９とが接続されている。脱脂炉１は、上記各構成機器の駆動を制御する制御装置（図示せず）を有する。
In the furnace body 2, a storage shelf 3 for storing a plurality of processed products W, a muffle 4 surrounding the storage shelf 3, a heater 5 for heating the processed products W via the muffle 4, a muffle 4 and a heater 5 are provided. A surrounding heat insulating chamber 6 is provided. Further, the furnace body 2 includes a carrier gas supply system 7 that supplies a carrier gas into the furnace body 2, a main exhaust system 8 that controls the atmospheric pressure in the furnace, and a degrease that exhausts wax vapor generated in the muffle 4. An exhaust system 9 is connected. The degreasing furnace 1 has a control device (not shown) for controlling the driving of each of the above components.
収容棚３は、複数の処理品Ｗを収容する複数の段を備える棚構造を有する。収容棚３は、複数の処理品Ｗに対しヒーター５の熱を伝導する熱伝導経路を形成するように機能する。昇温速度の最も速い収容棚３の隅部には、その隅部に配置された処理品（第１の粉末成型品）Ｗ１の温度を計測する温度センサ５１が設けられている。また、昇温速度の最も遅い収容棚３の中央部には、収容棚３の中央部に配置された処理品（第２の粉末成型品）Ｗ２の温度を計測する温度センサ５２が設けられている。温度センサ５１，５２の計測結果は、制御装置に出力される。温度センサ５１，５２としては、ここでは熱電対が用いられるが、例えば放射温度計のような非接触式のセンサを用いて温度を計測してもよい。
なお、本実施形態では複数の処理品Ｗを収納する場合について説明しているが、処理品Ｗが１つの場合には、１つの処理品Ｗを収容するのに適した収容棚３を準備すればよい。
また、温度センサ５１，５２についても、１つの処理品Ｗの異なる部分（第１の位置，第２の位置）の温度をそれぞれ計測するように適宜配置する。 Thestorage shelf 3 has a shelf structure including a plurality of stages for storing a plurality of processed products W. The storage shelf 3 functions so as to form a heat conduction path for conducting heat of the heater 5 to the plurality of processed products W. A temperature sensor 51 for measuring the temperature of the processed product (first powder molded product) W1 disposed at the corner is provided at the corner of the storage shelf 3 having the fastest temperature increase rate. In addition, a temperature sensor 52 that measures the temperature of the processed product (second powder molded product) W2 disposed in the central portion of the storage shelf 3 is provided in the central portion of the storage shelf 3 having the slowest temperature increase rate. Yes. The measurement results of the temperature sensors 51 and 52 are output to the control device. Here, thermocouples are used as the temperature sensors 51 and 52, but the temperature may be measured using a non-contact type sensor such as a radiation thermometer.
In this embodiment, the case where a plurality of processed products W are stored is described. However, when there is one processed product W, astorage shelf 3 suitable for storing one processed product W is prepared. That's fine.
Further, the temperature sensors 51 and 52 are also appropriately arranged so as to measure the temperatures of different portions (first position and second position) of one processed product W, respectively.
なお、本実施形態では複数の処理品Ｗを収納する場合について説明しているが、処理品Ｗが１つの場合には、１つの処理品Ｗを収容するのに適した収容棚３を準備すればよい。
また、温度センサ５１，５２についても、１つの処理品Ｗの異なる部分（第１の位置，第２の位置）の温度をそれぞれ計測するように適宜配置する。 The
In this embodiment, the case where a plurality of processed products W are stored is described. However, when there is one processed product W, a
Further, the
ヒーター５は、箱状のマッフル４の上下に対となって設けられている。ヒーター５は、マッフル４を輻射加熱し、マッフル４から伝わる熱で処理品Ｗを間接的に加熱する。ヒーター５の温度（炉内の温度）は、制御装置によって管理される。
断熱室６には、例えばグラファイトウールやセラミックウール等のウール系の断熱材が用いられている。断熱室６は箱型であり、マッフル４及びヒーター５の外側を囲うようにして設けられている。 Theheaters 5 are provided in pairs above and below the box-shaped muffle 4. The heater 5 radiates and heats the muffle 4 and indirectly heats the processed product W with heat transmitted from the muffle 4. The temperature of the heater 5 (temperature in the furnace) is managed by a control device.
For theheat insulation chamber 6, for example, a wool-based heat insulating material such as graphite wool or ceramic wool is used. The heat insulation chamber 6 has a box shape and is provided so as to surround the outside of the muffle 4 and the heater 5.
断熱室６には、例えばグラファイトウールやセラミックウール等のウール系の断熱材が用いられている。断熱室６は箱型であり、マッフル４及びヒーター５の外側を囲うようにして設けられている。 The
For the
キャリアガス供給系７は、炉体２内にキャリアガスを供給可能に配管されたキャリアガス供給ライン７１を有する。キャリアガス供給系７から供給されるキャリアガスは、窒素ガス、アルゴンガスやヘリウムガス、あるいはそれらの混合ガス等の不活性ガスからなる。また、キャリアガス供給系７には、炉体２内の雰囲気圧力を計測可能な不図示の圧力センサが設けられている。圧力センサの計測結果は、制御装置に出力される。
The carrier gas supply system 7 has a carrier gas supply line 71 provided in the furnace body 2 so as to be able to supply the carrier gas. The carrier gas supplied from the carrier gas supply system 7 is made of an inert gas such as nitrogen gas, argon gas, helium gas, or a mixed gas thereof. The carrier gas supply system 7 is provided with a pressure sensor (not shown) that can measure the atmospheric pressure in the furnace body 2. The measurement result of the pressure sensor is output to the control device.
主排気系８は、マッフル４の外から吸気可能に配管された主排気ライン８１を有する。主排気ライン８１には、メカニカルポンプ８２、ロータリーポンプ８３が設けられている。
メカニカルポンプ８２及びロータリーポンプ８３は、制御装置の制御の下、マッフル４の内部における減圧・真空雰囲気の度合いに応じて直列的に駆動したり、単機で駆動する。また、主排気系８には、マッフル４の内部の雰囲気圧力を計測可能な不図示の圧力センサが設けられている。圧力センサの計測結果は、制御装置に出力される。 Themain exhaust system 8 has a main exhaust line 81 that is piped so that intake from the outside of the muffle 4 is possible. The main exhaust line 81 is provided with a mechanical pump 82 and a rotary pump 83.
Themechanical pump 82 and the rotary pump 83 are driven in series according to the degree of the reduced pressure / vacuum atmosphere in the muffle 4 under the control of the control device, or are driven by a single machine. The main exhaust system 8 is provided with a pressure sensor (not shown) that can measure the atmospheric pressure inside the muffle 4. The measurement result of the pressure sensor is output to the control device.
メカニカルポンプ８２及びロータリーポンプ８３は、制御装置の制御の下、マッフル４の内部における減圧・真空雰囲気の度合いに応じて直列的に駆動したり、単機で駆動する。また、主排気系８には、マッフル４の内部の雰囲気圧力を計測可能な不図示の圧力センサが設けられている。圧力センサの計測結果は、制御装置に出力される。 The
The
脱脂排気系９は、マッフル４の内部に生じたワックス蒸気を吸気可能に配管された脱脂排気ライン９１を有する。脱脂排気ライン９１には、ワックストラップ９２が設けられている。ワックストラップ９２は、ワックス蒸気を冷却することでワックスを回収する。
また、脱脂排気ライン９１は、バイパスライン９３を介して主排気ライン８１と接続されており、脱脂排気系９からのワックス蒸気の吸気は、ロータリーポンプ８３を駆動させることで実施される。 The degreasingexhaust system 9 has a degreasing exhaust line 91 that is piped so that wax vapor generated inside the muffle 4 can be sucked. The degreasing exhaust line 91 is provided with a wax trap 92. The wax trap 92 collects wax by cooling the wax vapor.
The degreasingexhaust line 91 is connected to the main exhaust line 81 via a bypass line 93, and the intake of wax vapor from the degreasing exhaust system 9 is performed by driving the rotary pump 83.
また、脱脂排気ライン９１は、バイパスライン９３を介して主排気ライン８１と接続されており、脱脂排気系９からのワックス蒸気の吸気は、ロータリーポンプ８３を駆動させることで実施される。 The degreasing
The degreasing
続いて、上記構成の脱脂炉１を用いた処理品Ｗの脱脂方法について図２を参照して説明する。
図２は、本発明の第１実施形態における脱脂方法を説明するためのグラフである。図２において、縦軸は温度を、横軸は時間を示す。また、図２において、実線は炉内（ヒーター５）の温度変化を示し、破線は処理品Ｗ１の温度変化を示し、一点鎖線は処理品Ｗ２の温度変化を示す。 Next, a degreasing method for the processed product W using thedegreasing furnace 1 having the above-described configuration will be described with reference to FIG.
FIG. 2 is a graph for explaining a degreasing method according to the first embodiment of the present invention. In FIG. 2, the vertical axis represents temperature and the horizontal axis represents time. In FIG. 2, the solid line indicates the temperature change in the furnace (heater 5), the broken line indicates the temperature change of the processed product W1, and the alternate long and short dash line indicates the temperature change of the processed product W2.
図２は、本発明の第１実施形態における脱脂方法を説明するためのグラフである。図２において、縦軸は温度を、横軸は時間を示す。また、図２において、実線は炉内（ヒーター５）の温度変化を示し、破線は処理品Ｗ１の温度変化を示し、一点鎖線は処理品Ｗ２の温度変化を示す。 Next, a degreasing method for the processed product W using the
FIG. 2 is a graph for explaining a degreasing method according to the first embodiment of the present invention. In FIG. 2, the vertical axis represents temperature and the horizontal axis represents time. In FIG. 2, the solid line indicates the temperature change in the furnace (heater 5), the broken line indicates the temperature change of the processed product W1, and the alternate long and short dash line indicates the temperature change of the processed product W2.
先ず、主排気系８により、マッフル４の内部に真空雰囲気を形成する。このときのワックスの蒸発点（蒸発温度）Ｔｖは、図２に示すように、約２６０℃となっている。
ステップＳ１では、ヒーター５に通電させ、炉内の温度を常温からワックスの蒸発点Ｔｖまで昇温させる。このとき、処理品Ｗ１と処理品Ｗ２との間には、配置位置の違いにより伝熱の度合いが異なり、温度差が生じる。 First, a vacuum atmosphere is formed inside themuffle 4 by the main exhaust system 8. At this time, the evaporation point (evaporation temperature) Tv of the wax is about 260 ° C. as shown in FIG.
In step S1, theheater 5 is energized to raise the temperature in the furnace from room temperature to the wax evaporation point Tv. At this time, the degree of heat transfer differs between the processed product W1 and the processed product W2 due to the difference in the arrangement position, and a temperature difference occurs.
ステップＳ１では、ヒーター５に通電させ、炉内の温度を常温からワックスの蒸発点Ｔｖまで昇温させる。このとき、処理品Ｗ１と処理品Ｗ２との間には、配置位置の違いにより伝熱の度合いが異なり、温度差が生じる。 First, a vacuum atmosphere is formed inside the
In step S1, the
次に、ステップＳ２では、温度センサ５１，５２での計測結果が共に蒸発点Ｔｖに達する前に、炉内の温度を、蒸発点Ｔｖにおいて所定時間保持する（第２保持工程）。
このステップＳ２では、処理品Ｗ１及び処理品Ｗ２が共にワックスの蒸発点Ｔｖ近傍になるまでの間、炉内の温度を蒸発点Ｔｖで保持する。これにより、処理品Ｗ間の温度を略均一にすることで、脱脂処理するステップＳ３において設定された温度への昇温が開始できる状態にする。このため、ステップＳ３での処理品Ｗの温度とワックスの蒸発点Ｔｖとの温度差が比較的大きい場合でも、処理品Ｗ間においてワックスを均一に脱脂することができる。また、処理品Ｗの温度が急激に上昇して炭化してしまうことを未然に防ぐことが可能となる。本実施形態のステップＳ２は、温度センサ５１，５２の計測結果が共に温度Ｔ３（Ｔ３＝Ｔｖ－２０℃）に達する適正な時間に到達したら終了する。 Next, in step S2, the temperature in the furnace is held for a predetermined time at the evaporation point Tv before the measurement results of the temperature sensors 51 and 52 reach the evaporation point Tv (second holding step).
In this step S2, the temperature in the furnace is maintained at the evaporation point Tv until both the processed product W1 and the processed product W2 are close to the wax evaporation point Tv. Thereby, by making the temperature between the processed products W substantially uniform, a temperature rise to the temperature set in step S3 for performing the degreasing process can be started. For this reason, even when the temperature difference between the temperature of the processed product W and the wax evaporation point Tv in step S3 is relatively large, the wax can be uniformly degreased between the processed products W. In addition, it is possible to prevent the temperature of the processed product W from rapidly rising and carbonizing. Step S2 of the present embodiment ends when both the measurement results of the temperature sensors 51 and 52 reach an appropriate time for reaching the temperature T3 (T3 = Tv−20 ° C.).
このステップＳ２では、処理品Ｗ１及び処理品Ｗ２が共にワックスの蒸発点Ｔｖ近傍になるまでの間、炉内の温度を蒸発点Ｔｖで保持する。これにより、処理品Ｗ間の温度を略均一にすることで、脱脂処理するステップＳ３において設定された温度への昇温が開始できる状態にする。このため、ステップＳ３での処理品Ｗの温度とワックスの蒸発点Ｔｖとの温度差が比較的大きい場合でも、処理品Ｗ間においてワックスを均一に脱脂することができる。また、処理品Ｗの温度が急激に上昇して炭化してしまうことを未然に防ぐことが可能となる。本実施形態のステップＳ２は、温度センサ５１，５２の計測結果が共に温度Ｔ３（Ｔ３＝Ｔｖ－２０℃）に達する適正な時間に到達したら終了する。 Next, in step S2, the temperature in the furnace is held for a predetermined time at the evaporation point Tv before the measurement results of the
In this step S2, the temperature in the furnace is maintained at the evaporation point Tv until both the processed product W1 and the processed product W2 are close to the wax evaporation point Tv. Thereby, by making the temperature between the processed products W substantially uniform, a temperature rise to the temperature set in step S3 for performing the degreasing process can be started. For this reason, even when the temperature difference between the temperature of the processed product W and the wax evaporation point Tv in step S3 is relatively large, the wax can be uniformly degreased between the processed products W. In addition, it is possible to prevent the temperature of the processed product W from rapidly rising and carbonizing. Step S2 of the present embodiment ends when both the measurement results of the
次に、ステップＳ３では、炉内の温度を、ワックスが蒸発する蒸発点Ｔｖより高く、ワックスが炭化する炭化温度より低い範囲内で所定時間保持する（保持工程）。
このステップＳ３では、炉内の温度を、所定時間保持することで、処理品Ｗ間の温度差の拡大を抑えると共に、炉内における熱伝導によりその温度差を緩和しつつ脱脂を行う。
更に、ステップＳ３では、処理品Ｗ１及び処理品Ｗ２の温度がＴ３に達した後に、キープ温度Ｔ２（Ｔ２＝Ｔｖ＋３０℃）まで炉内の温度を緩昇温する緩昇温処理と、キープ温度Ｔ２で炉内の温度を保持するキープ処理とを行う。 Next, in step S3, the temperature in the furnace is held for a predetermined time within a range higher than the evaporation point Tv at which the wax evaporates and lower than the carbonization temperature at which the wax is carbonized (holding step).
In this step S3, by keeping the temperature in the furnace for a predetermined time, the expansion of the temperature difference between the processed products W is suppressed, and degreasing is performed while relaxing the temperature difference by heat conduction in the furnace.
Further, in step S3, after the temperatures of the processed product W1 and the processed product W2 reach T3, a slow temperature increasing process for gradually increasing the temperature in the furnace to a keep temperature T2 (T2 = Tv + 30 ° C.), and a keep temperature T2 And keep processing to maintain the temperature in the furnace.
このステップＳ３では、炉内の温度を、所定時間保持することで、処理品Ｗ間の温度差の拡大を抑えると共に、炉内における熱伝導によりその温度差を緩和しつつ脱脂を行う。
更に、ステップＳ３では、処理品Ｗ１及び処理品Ｗ２の温度がＴ３に達した後に、キープ温度Ｔ２（Ｔ２＝Ｔｖ＋３０℃）まで炉内の温度を緩昇温する緩昇温処理と、キープ温度Ｔ２で炉内の温度を保持するキープ処理とを行う。 Next, in step S3, the temperature in the furnace is held for a predetermined time within a range higher than the evaporation point Tv at which the wax evaporates and lower than the carbonization temperature at which the wax is carbonized (holding step).
In this step S3, by keeping the temperature in the furnace for a predetermined time, the expansion of the temperature difference between the processed products W is suppressed, and degreasing is performed while relaxing the temperature difference by heat conduction in the furnace.
Further, in step S3, after the temperatures of the processed product W1 and the processed product W2 reach T3, a slow temperature increasing process for gradually increasing the temperature in the furnace to a keep temperature T2 (T2 = Tv + 30 ° C.), and a keep temperature T2 And keep processing to maintain the temperature in the furnace.
ステップＳ３では、炉内の温度を、ワックスの蒸発点Ｔｖより高い温度とすることにより処理品Ｗからワックスを確実に蒸発させる。炉内の温度を、ワックスの蒸発点Ｔｖまで昇温すれば、通常、ワックスは蒸発する。しかしながら、ワックスの固体差や、処理品Ｗ間の昇温状況の違い等のため、炉内の温度を蒸発点Ｔｖに保持すると、ワックスが蒸発する部分と蒸発しない部分が生じてしまう。このため、本実施形態では、ステップＳ３において蒸発点Ｔｖよりも高めの温度で、炉内の温度を保持することにより、ワックスを確実に蒸発させる。
In step S3, the wax is reliably evaporated from the processed product W by setting the temperature in the furnace to a temperature higher than the evaporation point Tv of the wax. If the temperature in the furnace is raised to the evaporation point Tv of the wax, the wax usually evaporates. However, if the temperature in the furnace is maintained at the evaporation point Tv due to differences in wax solids or differences in temperature rise between the processed products W, a portion where the wax evaporates and a portion where the wax does not evaporate are generated. For this reason, in this embodiment, the wax is reliably evaporated by maintaining the temperature in the furnace at a temperature higher than the evaporation point Tv in step S3.
また、ステップＳ３では、炉内の温度を、処理品Ｗが浸炭する温度より低いキープ温度Ｔ２において維持することにより、処理品Ｗの浸炭の発生を抑制する。なお、処理品Ｗの浸炭温度は、ワックスの種類や炉内の圧力によって定まる。本実施形態の処理品Ｗの浸炭温度は、例えば蒸発点Ｔｖよりも約５０℃高い温度である。キープ温度Ｔ２は、蒸発点Ｔｖより高い温度とするが、高い温度にしすぎると処理品Ｗが浸炭されてしまい、キープ温度Ｔ２が蒸発点Ｔｖに近すぎる場合だとワックスが蒸発しきらない可能性がある。これらの点を考慮し、キープ温度Ｔ２は、Ｔｖ＋約３０℃としている。
なお、ワックスの蒸発は、緩昇温処理においてほぼ完了されるが、ワックスの蒸発特性には個体差がある。そのため、緩昇温処理後にワックスが処理品Ｗから完全に抜け切っているとは限らない。これに対し、ステップＳ３の時間を調節するために、ステップＳ３の終わりに、キープ温度Ｔ２において炉内の温度を保持するキープ処理を更に設けている（調節工程）。本実施形態では、１時間のキープ処理を実施している。 Moreover, in step S3, generation | occurrence | production of the carburizing of the processed goods W is suppressed by maintaining the temperature in a furnace in the keep temperature T2 lower than the temperature which the processed goods W carburize. The carburizing temperature of the processed product W is determined by the type of wax and the pressure in the furnace. The carburizing temperature of the processed product W of this embodiment is, for example, about 50 ° C. higher than the evaporation point Tv. The keep temperature T2 is higher than the evaporation point Tv. However, if the temperature is too high, the processed product W is carburized, and if the keep temperature T2 is too close to the evaporation point Tv, the wax may not evaporate. There is. Considering these points, the keep temperature T2 is set to Tv + about 30 ° C.
It should be noted that the evaporation of the wax is almost completed in the slow temperature increase process, but there are individual differences in the evaporation characteristics of the wax. For this reason, the wax is not always completely removed from the processed product W after the slow temperature increase process. On the other hand, in order to adjust the time of step S3, at the end of step S3, a keep process for maintaining the temperature in the furnace at the keep temperature T2 is further provided (adjustment process). In this embodiment, a one-hour keep process is performed.
なお、ワックスの蒸発は、緩昇温処理においてほぼ完了されるが、ワックスの蒸発特性には個体差がある。そのため、緩昇温処理後にワックスが処理品Ｗから完全に抜け切っているとは限らない。これに対し、ステップＳ３の時間を調節するために、ステップＳ３の終わりに、キープ温度Ｔ２において炉内の温度を保持するキープ処理を更に設けている（調節工程）。本実施形態では、１時間のキープ処理を実施している。 Moreover, in step S3, generation | occurrence | production of the carburizing of the processed goods W is suppressed by maintaining the temperature in a furnace in the keep temperature T2 lower than the temperature which the processed goods W carburize. The carburizing temperature of the processed product W is determined by the type of wax and the pressure in the furnace. The carburizing temperature of the processed product W of this embodiment is, for example, about 50 ° C. higher than the evaporation point Tv. The keep temperature T2 is higher than the evaporation point Tv. However, if the temperature is too high, the processed product W is carburized, and if the keep temperature T2 is too close to the evaporation point Tv, the wax may not evaporate. There is. Considering these points, the keep temperature T2 is set to Tv + about 30 ° C.
It should be noted that the evaporation of the wax is almost completed in the slow temperature increase process, but there are individual differences in the evaporation characteristics of the wax. For this reason, the wax is not always completely removed from the processed product W after the slow temperature increase process. On the other hand, in order to adjust the time of step S3, at the end of step S3, a keep process for maintaining the temperature in the furnace at the keep temperature T2 is further provided (adjustment process). In this embodiment, a one-hour keep process is performed.
次に、ステップＳ４では、炉内の温度を、キープ温度Ｔ２から処理品Ｗを焼結させる焼結温度Ｔ１まで昇温させる。
最後に、ステップＳ５では、温度センサ５１，５２での計測結果が共に焼結温度Ｔ１に達するまで、炉内の温度を焼結温度Ｔ１において所定時間保持して、処理品Ｗを焼結させる。以上の処理により、製品の均質化を図ることができる。ちなみに、本実施例における総処理時間は、９．５時間である。 Next, in step S4, the temperature in the furnace is raised from the keep temperature T2 to the sintering temperature T1 at which the processed product W is sintered.
Finally, in step S5, the processed product W is sintered by holding the temperature in the furnace at the sintering temperature T1 for a predetermined time until both the measurement results of the temperature sensors 51 and 52 reach the sintering temperature T1. By the above processing, the product can be homogenized. Incidentally, the total processing time in this embodiment is 9.5 hours.
最後に、ステップＳ５では、温度センサ５１，５２での計測結果が共に焼結温度Ｔ１に達するまで、炉内の温度を焼結温度Ｔ１において所定時間保持して、処理品Ｗを焼結させる。以上の処理により、製品の均質化を図ることができる。ちなみに、本実施例における総処理時間は、９．５時間である。 Next, in step S4, the temperature in the furnace is raised from the keep temperature T2 to the sintering temperature T1 at which the processed product W is sintered.
Finally, in step S5, the processed product W is sintered by holding the temperature in the furnace at the sintering temperature T1 for a predetermined time until both the measurement results of the
上述の第１実施形態は、少なくとも炉内において互いに異なる位置に配置された処理品Ｗ１及び処理品Ｗ２（粉末成型品）に含まれるワックスを、加熱して脱脂する脱脂方法である。この方法によれば、上記炉内の温度を、ワックスが蒸発する蒸発点Ｔｖより高く、且つ処理品Ｗが浸炭する温度より低い範囲内で所定時間保持するステップＳ３（保持工程）を有する。このステップＳ３では、炉内の温度を、所定時間保持することで、処理品Ｗ間あるいは一つの処理品Ｗの異なる部分の温度差の拡大が抑えられると共に、炉内における熱伝導により処理品Ｗ間あるいは一つの処理品Ｗの異なる部分の温度差が緩和される。また、ステップＳ３の保持工程では、炉内の温度を、ワックスの蒸発点Ｔｖ（有機結合剤の蒸発温度）より高い温度とすることにより処理品Ｗからワックスを確実に蒸発させることができる。更に、炉内の温度を、ワックスが蒸発して発生したガスによる浸炭が起こる温度より低い温度とすることで、処理品Ｗの浸炭の発生を抑制できる。したがって、本発明の第１実施形態では、完成後の製品の品質のバラツキを低減できる。
The first embodiment described above is a degreasing method for heating and degreasing the wax contained in the processed product W1 and the processed product W2 (powder molded product) arranged at different positions in the furnace. According to this method, there is a step S3 (holding step) in which the temperature in the furnace is held for a predetermined time within a range higher than the evaporation point Tv at which the wax evaporates and lower than the temperature at which the processed product W is carburized. In this step S3, by maintaining the temperature in the furnace for a predetermined time, the expansion of the temperature difference between the processed products W or different parts of one processed product W can be suppressed, and the processed product W can be transmitted by heat conduction in the furnace. The temperature difference between the different parts of the one processed product W is relaxed. Further, in the holding step of Step S3, the wax can be reliably evaporated from the processed product W by setting the temperature in the furnace to a temperature higher than the wax evaporation point Tv (evaporation temperature of the organic binder). Furthermore, by setting the temperature in the furnace to a temperature lower than the temperature at which carburization by the gas generated by the evaporation of wax occurs, carburization of the processed product W can be suppressed. Therefore, in the first embodiment of the present invention, variations in product quality after completion can be reduced.
また、上述の第１実施形態では、ステップＳ３内に調節工程を設けたことで、ワックスの固体差や、処理品Ｗ１及び処理品Ｗ２の昇温速度の違いに対応でき、これら処理品の間において均一な脱脂を実現できる。
Further, in the above-described first embodiment, by providing the adjustment step in step S3, it is possible to cope with the difference in wax solids and the difference in the heating rate between the processed product W1 and the processed product W2. Can achieve uniform degreasing.
また、第１実施形態では、複数の処理品Ｗについては、少なくとも互いに異なる位置に、処理品Ｗ１（第１の粉末成型品）及び処理品Ｗ２（第２の粉末成型品）が配置され、処理品Ｗ１の温度を計測する第１計測工程と、処理品Ｗ２の温度を計測する第２計測工程とを有する。そして、第１計測工程及び第２計測工程での計測結果が共に蒸発温度に達する前に、炉内の温度を、この蒸発温度において所定時間保持する第２保持工程を有する。
従って、処理品Ｗ１及び処理品Ｗ２が共にワックスの蒸発温度になるまでの間、炉内の温度をその蒸発温度で保持することにより、処理品Ｗ１及び処理品Ｗ２の温度を略均一にした後に、保持工程での温度への昇温が開始できる状態にする。このため、保持工程での温度と処理品Ｗ１及び処理品Ｗ２のワックスの蒸発温度との温度差が比較的大きい場合でも、処理品Ｗ１及び処理品Ｗ２間においてワックスが均一に脱脂され、ワックスが蒸発して発生したガスによる処理品Ｗの浸炭の発生を抑制できる。 In the first embodiment, with respect to the plurality of processed products W, the processed product W1 (first powder molded product) and the processed product W2 (second powder molded product) are arranged at least at positions different from each other. It has the 1st measurement process which measures the temperature of goods W1, and the 2nd measurement process which measures the temperature of processed goods W2. And before the measurement result in a 1st measurement process and a 2nd measurement process reaches evaporation temperature, it has the 2nd holding process which hold | maintains the temperature in a furnace for this predetermined time in this evaporation temperature.
Therefore, after both the processed product W1 and the processed product W2 reach the evaporation temperature of the wax, the temperature of the processed product W1 and the processed product W2 is made substantially uniform by maintaining the temperature in the furnace at the evaporation temperature. The temperature is raised to the temperature in the holding step. For this reason, even when the temperature difference between the temperature in the holding step and the evaporation temperature of the wax of the processed product W1 and the processed product W2 is relatively large, the wax is uniformly degreased between the processed product W1 and the processed product W2, and the wax is The carburization of the processed product W due to the gas generated by evaporation can be suppressed.
従って、処理品Ｗ１及び処理品Ｗ２が共にワックスの蒸発温度になるまでの間、炉内の温度をその蒸発温度で保持することにより、処理品Ｗ１及び処理品Ｗ２の温度を略均一にした後に、保持工程での温度への昇温が開始できる状態にする。このため、保持工程での温度と処理品Ｗ１及び処理品Ｗ２のワックスの蒸発温度との温度差が比較的大きい場合でも、処理品Ｗ１及び処理品Ｗ２間においてワックスが均一に脱脂され、ワックスが蒸発して発生したガスによる処理品Ｗの浸炭の発生を抑制できる。 In the first embodiment, with respect to the plurality of processed products W, the processed product W1 (first powder molded product) and the processed product W2 (second powder molded product) are arranged at least at positions different from each other. It has the 1st measurement process which measures the temperature of goods W1, and the 2nd measurement process which measures the temperature of processed goods W2. And before the measurement result in a 1st measurement process and a 2nd measurement process reaches evaporation temperature, it has the 2nd holding process which hold | maintains the temperature in a furnace for this predetermined time in this evaporation temperature.
Therefore, after both the processed product W1 and the processed product W2 reach the evaporation temperature of the wax, the temperature of the processed product W1 and the processed product W2 is made substantially uniform by maintaining the temperature in the furnace at the evaporation temperature. The temperature is raised to the temperature in the holding step. For this reason, even when the temperature difference between the temperature in the holding step and the evaporation temperature of the wax of the processed product W1 and the processed product W2 is relatively large, the wax is uniformly degreased between the processed product W1 and the processed product W2, and the wax is The carburization of the processed product W due to the gas generated by evaporation can be suppressed.
また、第１実施形態では、一つの処理品Ｗについては、その処理品Ｗの異なる部分の第１の位置の温度を計測する第１計測工程と、この処理品Ｗの第１の位置とは異なる第２の位置の温度を計測する第２計測工程とを有する。そして第１計測工程及び第２計測工程での計測結果が共に蒸発温度に達する前に、炉内の温度を、この蒸発温度において所定時間保持する第２保持工程を有する。
従って、一つの処理品Ｗにおいて第１の位置の部分及び第２の位置の部分が共に処理品Ｗのワックスの蒸発温度になるまでの間、炉内の温度をワックスの蒸発温度で保持することにより、一つの処理品Ｗの部分間の温度を略均一にした後に、保持工程での温度への昇温が開始できる状態にする。このため、保持工程での温度とワックスの蒸発温度との温度差が比較的大きい場合でも、一つの処理品Ｗの部分間においてワックスが均一に脱脂され、ワックスが蒸発して発生したガスによる処理品Ｗの浸炭の発生を抑制できる。 In the first embodiment, for one processed product W, the first measurement step of measuring the temperature at the first position of a different part of the processed product W and the first position of the processed product W are: And a second measuring step for measuring the temperature at a different second position. And before the measurement result in a 1st measurement process and a 2nd measurement process reaches evaporation temperature, it has the 2nd holding process which hold | maintains the temperature in a furnace for this predetermined time in this evaporation temperature.
Therefore, the temperature in the furnace is maintained at the wax evaporation temperature until both the first position portion and the second position portion of one processed product W reach the wax evaporation temperature of the processed product W. Thus, after the temperature between the portions of one processed product W is made substantially uniform, a temperature rise to the temperature in the holding step can be started. For this reason, even when the temperature difference between the temperature in the holding process and the evaporation temperature of the wax is relatively large, the wax is uniformly degreased between the portions of one processed product W, and the treatment with the gas generated by the evaporation of the wax is performed. The carburization of the product W can be suppressed.
従って、一つの処理品Ｗにおいて第１の位置の部分及び第２の位置の部分が共に処理品Ｗのワックスの蒸発温度になるまでの間、炉内の温度をワックスの蒸発温度で保持することにより、一つの処理品Ｗの部分間の温度を略均一にした後に、保持工程での温度への昇温が開始できる状態にする。このため、保持工程での温度とワックスの蒸発温度との温度差が比較的大きい場合でも、一つの処理品Ｗの部分間においてワックスが均一に脱脂され、ワックスが蒸発して発生したガスによる処理品Ｗの浸炭の発生を抑制できる。 In the first embodiment, for one processed product W, the first measurement step of measuring the temperature at the first position of a different part of the processed product W and the first position of the processed product W are: And a second measuring step for measuring the temperature at a different second position. And before the measurement result in a 1st measurement process and a 2nd measurement process reaches evaporation temperature, it has the 2nd holding process which hold | maintains the temperature in a furnace for this predetermined time in this evaporation temperature.
Therefore, the temperature in the furnace is maintained at the wax evaporation temperature until both the first position portion and the second position portion of one processed product W reach the wax evaporation temperature of the processed product W. Thus, after the temperature between the portions of one processed product W is made substantially uniform, a temperature rise to the temperature in the holding step can be started. For this reason, even when the temperature difference between the temperature in the holding process and the evaporation temperature of the wax is relatively large, the wax is uniformly degreased between the portions of one processed product W, and the treatment with the gas generated by the evaporation of the wax is performed. The carburization of the product W can be suppressed.
（第２実施形態）
次に、本発明の第２実施形態について説明する。以下の説明において、上述の実施形態と同一又は同等の構成部分については同一の符号を付し、その説明を簡略若しくは省略する。
図３は、本発明の第２実施形態における脱脂方法を説明するためのグラフである。上記実施形態と同様に、図３のグラフでは、縦軸は温度を、横軸は時間を示す。また、図３において、実線は炉内（ヒーター５）の温度変化を示し、破線は処理品Ｗ１の温度変化を示し、一点鎖線は処理品Ｗ２の温度変化を示す。 (Second Embodiment)
Next, a second embodiment of the present invention will be described. In the following description, the same or equivalent components as those of the above-described embodiment are denoted by the same reference numerals, and the description thereof is simplified or omitted.
FIG. 3 is a graph for explaining a degreasing method according to the second embodiment of the present invention. Similar to the above embodiment, in the graph of FIG. 3, the vertical axis represents temperature and the horizontal axis represents time. In FIG. 3, the solid line indicates the temperature change in the furnace (heater 5), the broken line indicates the temperature change of the processed product W1, and the alternate long and short dash line indicates the temperature change of the processed product W2.
次に、本発明の第２実施形態について説明する。以下の説明において、上述の実施形態と同一又は同等の構成部分については同一の符号を付し、その説明を簡略若しくは省略する。
図３は、本発明の第２実施形態における脱脂方法を説明するためのグラフである。上記実施形態と同様に、図３のグラフでは、縦軸は温度を、横軸は時間を示す。また、図３において、実線は炉内（ヒーター５）の温度変化を示し、破線は処理品Ｗ１の温度変化を示し、一点鎖線は処理品Ｗ２の温度変化を示す。 (Second Embodiment)
Next, a second embodiment of the present invention will be described. In the following description, the same or equivalent components as those of the above-described embodiment are denoted by the same reference numerals, and the description thereof is simplified or omitted.
FIG. 3 is a graph for explaining a degreasing method according to the second embodiment of the present invention. Similar to the above embodiment, in the graph of FIG. 3, the vertical axis represents temperature and the horizontal axis represents time. In FIG. 3, the solid line indicates the temperature change in the furnace (heater 5), the broken line indicates the temperature change of the processed product W1, and the alternate long and short dash line indicates the temperature change of the processed product W2.
第２実施形態では、上記実施形態よりも処理時間を短縮するために、炉内の雰囲気圧力を調節して、ワックスの蒸発点Ｔｖを高めている（圧力調節工程）。炉内の雰囲気圧力を高めると、処理品Ｗへの伝熱性が増すため、処理時間の短縮ができる。
炉内の雰囲気圧力の調節は、主排気系８の駆動やキャリアガス供給系７の駆動を制御することで行われる。第１実施形態では、真空雰囲気の下において脱脂を行っていたが、第２実施形態では、主排気系８を暖機運転させ、キャリアガス供給系７から所定量の不活性ガスを供給して、真空雰囲気よりも高い圧力の減圧雰囲気の下において脱脂を行う。図３に示すように、第２実施形態のワックスの蒸発点Ｔｖは、約３５０℃である。ワックスの蒸発点Ｔｖを高めると、ステップＳ１及びステップＳ２において、処理品Ｗに対する入熱量を高めることができる。また、ワックスの蒸発点Ｔｖを高めると、蒸発点Ｔｖと焼結温度Ｔ１との差が小さくなるため、ステップＳ４及びステップＳ５における焼結温度Ｔ１まで処理品Ｗを昇温させる時間を短縮することができる。ちなみに、本実施例における総処理時間は、８．５時間である。 本発明の第２実施形態では、第１実施形態で述べた工程に加えて、圧力調節工程を備えたことで、炉内の雰囲気圧力が高まり、処理品Ｗへの伝熱性が増すため、処理時間の短縮ができる。 In the second embodiment, in order to shorten the processing time compared to the above embodiment, the atmospheric pressure in the furnace is adjusted to increase the wax evaporation point Tv (pressure adjusting step). When the atmospheric pressure in the furnace is increased, the heat transfer to the processed product W is increased, so that the processing time can be shortened.
The atmospheric pressure in the furnace is adjusted by controlling the driving of themain exhaust system 8 and the driving of the carrier gas supply system 7. In the first embodiment, degreasing is performed under a vacuum atmosphere, but in the second embodiment, the main exhaust system 8 is warmed up and a predetermined amount of inert gas is supplied from the carrier gas supply system 7. Degreasing is performed under a reduced pressure atmosphere having a pressure higher than that of the vacuum atmosphere. As shown in FIG. 3, the evaporation point Tv of the wax of the second embodiment is about 350 ° C. When the evaporation point Tv of the wax is increased, the amount of heat input to the processed product W can be increased in step S1 and step S2. Moreover, since the difference between the evaporation point Tv and the sintering temperature T1 is reduced when the wax evaporation point Tv is increased, the time for raising the temperature of the processed product W to the sintering temperature T1 in steps S4 and S5 is shortened. Can do. Incidentally, the total processing time in this embodiment is 8.5 hours. In the second embodiment of the present invention, in addition to the steps described in the first embodiment, since the pressure adjustment step is provided, the atmospheric pressure in the furnace is increased and the heat transfer to the processed product W is increased. Time can be shortened.
炉内の雰囲気圧力の調節は、主排気系８の駆動やキャリアガス供給系７の駆動を制御することで行われる。第１実施形態では、真空雰囲気の下において脱脂を行っていたが、第２実施形態では、主排気系８を暖機運転させ、キャリアガス供給系７から所定量の不活性ガスを供給して、真空雰囲気よりも高い圧力の減圧雰囲気の下において脱脂を行う。図３に示すように、第２実施形態のワックスの蒸発点Ｔｖは、約３５０℃である。ワックスの蒸発点Ｔｖを高めると、ステップＳ１及びステップＳ２において、処理品Ｗに対する入熱量を高めることができる。また、ワックスの蒸発点Ｔｖを高めると、蒸発点Ｔｖと焼結温度Ｔ１との差が小さくなるため、ステップＳ４及びステップＳ５における焼結温度Ｔ１まで処理品Ｗを昇温させる時間を短縮することができる。ちなみに、本実施例における総処理時間は、８．５時間である。 本発明の第２実施形態では、第１実施形態で述べた工程に加えて、圧力調節工程を備えたことで、炉内の雰囲気圧力が高まり、処理品Ｗへの伝熱性が増すため、処理時間の短縮ができる。 In the second embodiment, in order to shorten the processing time compared to the above embodiment, the atmospheric pressure in the furnace is adjusted to increase the wax evaporation point Tv (pressure adjusting step). When the atmospheric pressure in the furnace is increased, the heat transfer to the processed product W is increased, so that the processing time can be shortened.
The atmospheric pressure in the furnace is adjusted by controlling the driving of the
（第３実施形態）
次に、本発明の第３実施形態について説明する。以下の説明において、上述の実施形態と同一又は同等の構成部分については同一の符号を付し、その説明を簡略若しくは省略する。
図４は、本発明の第３実施形態における脱脂方法を説明するためのグラフである。上記実施形態と同様に、図４のグラフでは、縦軸は温度を、横軸は時間を示す。また、図４において、実線は炉内（ヒーター５）の温度変化を示し、破線は処理品Ｗ１の温度変化を示し、一点鎖線は処理品Ｗ２の温度変化を示す。 (Third embodiment)
Next, a third embodiment of the present invention will be described. In the following description, the same or equivalent components as those of the above-described embodiment are denoted by the same reference numerals, and the description thereof is simplified or omitted.
FIG. 4 is a graph for explaining a degreasing method according to the third embodiment of the present invention. Similar to the above embodiment, in the graph of FIG. 4, the vertical axis represents temperature and the horizontal axis represents time. In FIG. 4, the solid line indicates the temperature change in the furnace (heater 5), the broken line indicates the temperature change of the processed product W1, and the alternate long and short dash line indicates the temperature change of the processed product W2.
次に、本発明の第３実施形態について説明する。以下の説明において、上述の実施形態と同一又は同等の構成部分については同一の符号を付し、その説明を簡略若しくは省略する。
図４は、本発明の第３実施形態における脱脂方法を説明するためのグラフである。上記実施形態と同様に、図４のグラフでは、縦軸は温度を、横軸は時間を示す。また、図４において、実線は炉内（ヒーター５）の温度変化を示し、破線は処理品Ｗ１の温度変化を示し、一点鎖線は処理品Ｗ２の温度変化を示す。 (Third embodiment)
Next, a third embodiment of the present invention will be described. In the following description, the same or equivalent components as those of the above-described embodiment are denoted by the same reference numerals, and the description thereof is simplified or omitted.
FIG. 4 is a graph for explaining a degreasing method according to the third embodiment of the present invention. Similar to the above embodiment, in the graph of FIG. 4, the vertical axis represents temperature and the horizontal axis represents time. In FIG. 4, the solid line indicates the temperature change in the furnace (heater 5), the broken line indicates the temperature change of the processed product W1, and the alternate long and short dash line indicates the temperature change of the processed product W2.
第３実施形態では、上記第１および第２実施形態よりも処理時間を短縮するために、第２実施形態の手法に加えて、ステップＳ２に移行する前に、炉内の温度を蒸発点Ｔｖ以上に昇温させるステップ（昇温工程）Ｓ１´を設ける。
ステップＳ１´では、初期の昇温において、炉内の温度を蒸発点Ｔｖよりも高い温度Ｔ４まで昇温させてから、蒸発点Ｔｖまで降温させる。ステップＳ１´における蒸発点Ｔｖまで降温は、ヒーター５の加熱を停止して、炉内雰囲気や水冷ジャケットによる吸熱により行われる。このステップＳ１´により、処理品Ｗに対する入熱量を高めて昇温速度を高められるので、処理時間の短縮が可能となる。なお、ステップＳ１´は、ステップＳ２の前に行われるため、処理品Ｗが浸炭温度より昇温することはない。さらに、ステップＳ２において、処理品Ｗの温度の上昇を未然に防ぐことができる。ちなみに、本実施例における総処理時間は、７．９時間である。
本発明の第３実施形態では、第１実施形態で述べた工程に加えて、昇温工程を備えたことで、炉内の温度が高まり処理品Ｗの昇温速度を早められるため、処理時間の短縮ができる。 In the third embodiment, in order to shorten the processing time compared to the first and second embodiments, in addition to the method of the second embodiment, the temperature in the furnace is set to the evaporation point Tv before moving to step S2. A step (temperature raising step) S1 ′ for raising the temperature is provided.
In step S1 ′, in the initial temperature rise, the temperature in the furnace is raised to a temperature T4 higher than the evaporation point Tv, and then lowered to the evaporation point Tv. The temperature is lowered to the evaporation point Tv in step S1 ′ by stopping the heating of theheater 5 and absorbing heat from the furnace atmosphere or a water cooling jacket. By this step S1 ′, the amount of heat input to the processed product W can be increased to increase the rate of temperature rise, so that the processing time can be shortened. In addition, since step S1 'is performed before step S2, the processed product W does not heat up from the carburizing temperature. Furthermore, in step S2, the temperature of the processed product W can be prevented from rising. Incidentally, the total processing time in this embodiment is 7.9 hours.
In the third embodiment of the present invention, in addition to the steps described in the first embodiment, since the temperature in the furnace increases and the temperature increase rate of the processed product W can be increased by providing the temperature increasing step, the processing time is increased. Can be shortened.
ステップＳ１´では、初期の昇温において、炉内の温度を蒸発点Ｔｖよりも高い温度Ｔ４まで昇温させてから、蒸発点Ｔｖまで降温させる。ステップＳ１´における蒸発点Ｔｖまで降温は、ヒーター５の加熱を停止して、炉内雰囲気や水冷ジャケットによる吸熱により行われる。このステップＳ１´により、処理品Ｗに対する入熱量を高めて昇温速度を高められるので、処理時間の短縮が可能となる。なお、ステップＳ１´は、ステップＳ２の前に行われるため、処理品Ｗが浸炭温度より昇温することはない。さらに、ステップＳ２において、処理品Ｗの温度の上昇を未然に防ぐことができる。ちなみに、本実施例における総処理時間は、７．９時間である。
本発明の第３実施形態では、第１実施形態で述べた工程に加えて、昇温工程を備えたことで、炉内の温度が高まり処理品Ｗの昇温速度を早められるため、処理時間の短縮ができる。 In the third embodiment, in order to shorten the processing time compared to the first and second embodiments, in addition to the method of the second embodiment, the temperature in the furnace is set to the evaporation point Tv before moving to step S2. A step (temperature raising step) S1 ′ for raising the temperature is provided.
In step S1 ′, in the initial temperature rise, the temperature in the furnace is raised to a temperature T4 higher than the evaporation point Tv, and then lowered to the evaporation point Tv. The temperature is lowered to the evaporation point Tv in step S1 ′ by stopping the heating of the
In the third embodiment of the present invention, in addition to the steps described in the first embodiment, since the temperature in the furnace increases and the temperature increase rate of the processed product W can be increased by providing the temperature increasing step, the processing time is increased. Can be shortened.
以上、図面を参照しながら本発明の好適な実施形態について説明したが、本発明は上記実施形態に限定されるものではない。上述した実施形態において示した各構成部材の諸形状や組み合わせ等は一例であって、本発明の主旨から逸脱しない範囲において設計要求等に基づき種々変更可能である。
The preferred embodiment of the present invention has been described above with reference to the drawings, but the present invention is not limited to the above embodiment. Various shapes, combinations, and the like of the constituent members shown in the above-described embodiments are examples, and various modifications can be made based on design requirements and the like without departing from the gist of the present invention.
例えば、上記実施形態では、ステップＳ１からステップＳ２を経てステップＳ３に移行すると説明したが、本発明はこれに限定されるものではなく、例えば、ステップＳ２を経ずにステップＳ１からステップＳ３に移行してもよい。
また、上記実施形態では、粉末成型品に含まれる有機結合剤としてワックスを例示して説明したが、本発明はこれに限定されるものではなく、バインダー等の他の種類の有機結合剤であってもよい。 For example, in the above-described embodiment, it has been described that the process proceeds from step S1 to step S3 through step S2, but the present invention is not limited to this. For example, the process proceeds from step S1 to step S3 without passing through step S2. May be.
In the above embodiment, the wax is exemplified as the organic binder contained in the powder molded product. However, the present invention is not limited to this, and other types of organic binders such as a binder may be used. May be.
また、上記実施形態では、粉末成型品に含まれる有機結合剤としてワックスを例示して説明したが、本発明はこれに限定されるものではなく、バインダー等の他の種類の有機結合剤であってもよい。 For example, in the above-described embodiment, it has been described that the process proceeds from step S1 to step S3 through step S2, but the present invention is not limited to this. For example, the process proceeds from step S1 to step S3 without passing through step S2. May be.
In the above embodiment, the wax is exemplified as the organic binder contained in the powder molded product. However, the present invention is not limited to this, and other types of organic binders such as a binder may be used. May be.
あるいは、複数の処理品Ｗを処理する場合だけではなく、１つの処理品Ｗを処理する場合にも本発明を適用することが出来る。この場合、上記実施形態では、第１の粉末成形品Ｗ１と第２の粉末成形品Ｗ２の温度をそれぞれ温度センサ５１、５２で計測して処理をしている。この処理を、１つの処理品Ｗにおける第１の位置の部分（例えば処理品Ｗの内側）とこれと異なる第２の位置の部分（例えば処理品Ｗの外側）とにそれぞれ温度センサ５１、５２を設けて温度計測して、本発明の脱脂方法を実施しても良い。これにより、１つの処理品Ｗの部分ごとにおける品質のバラツキを低減することが可能となる。
Alternatively, the present invention can be applied not only when processing a plurality of processed products W but also when processing a single processed product W. In this case, in the said embodiment, it processes by measuring the temperature of the 1st powder molded product W1 and the 2nd powder molded product W2 with the temperature sensors 51 and 52, respectively. The temperature sensors 51 and 52 are applied to a portion at a first position (for example, the inside of the processed product W) and a portion at a second position (for example, the outside of the processed product W) different from this processing, respectively. The temperature may be measured and the degreasing method of the present invention may be carried out. Thereby, it becomes possible to reduce the variation in quality for each portion of one processed product W.
本発明の脱脂方法によれば、粉末成型品の製品毎の品質のバラツキおよび一製品の各部分の品質のバラツキを低減でき、粉末成型品の処理時間も短縮できる。
According to the degreasing method of the present invention, it is possible to reduce the quality variation of each product of the powder molded product and the quality variation of each part of one product, and the processing time of the powder molded product can be shortened.
Ｓ２…ステップ（第２保持工程）、Ｓ３…ステップ（保持工程）、Ｓ１´…ステップ（昇温工程）、Ｔｖ…蒸発点（有機結合剤の蒸発温度）、Ｗ１…処理品（第１の粉末成型品）、Ｗ２…処理品（第２の粉末成型品）
S2 ... Step (second holding process), S3 ... Step (holding process), S1 '... Step (temperature raising process), Tv ... Evaporation point (evaporation temperature of organic binder), W1 ... Processed product (first powder) Molded product), W2 ... treated product (second powder molded product)
Claims (6)
- 炉内において一又は複数の粉末成型品に含まれる有機結合剤を、加熱して脱脂する脱脂方法であって、
前記炉内の温度を、前記有機結合剤が蒸発する蒸発温度より高く、前記粉末成型品が浸炭する温度より低い範囲内で所定時間保持する保持工程を有する脱脂方法。 A degreasing method of heating and degreasing an organic binder contained in one or a plurality of powder molded products in a furnace,
A degreasing method comprising a holding step of holding the temperature in the furnace for a predetermined time within a range higher than an evaporation temperature at which the organic binder evaporates and lower than a temperature at which the powder molded product is carburized. - 前記有機結合剤の蒸発特性に基づいて、前記保持工程の時間を調節する調節工程を更に有する請求項１に記載の脱脂方法。 The degreasing method according to claim 1, further comprising an adjusting step of adjusting a time of the holding step based on an evaporation characteristic of the organic binder.
- 前記炉内には、少なくとも互いに異なる位置に第１の粉末成型品及び第２の粉末成型品が配置されており、
前記第１の粉末成型品の温度を計測する第１計測工程と、前記第２の粉末成型品の温度を計測する第２計測工程とを有し、
前記第１計測工程及び前記第２計測工程での計測結果が共に前記蒸発温度に達する前に、前記炉内の温度を、前記蒸発温度において所定時間保持する第２保持工程を有する請求項１または２に記載の脱脂方法。 In the furnace, the first powder molded product and the second powder molded product are arranged at least at different positions,
A first measurement step of measuring the temperature of the first powder molded product, and a second measurement step of measuring the temperature of the second powder molded product,
2. A second holding step for holding the temperature in the furnace at the evaporation temperature for a predetermined time before both the measurement results in the first measurement step and the second measurement step reach the evaporation temperature. 2. The degreasing method according to 2. - 前記粉末成型品の第１の位置の温度を計測する第１計測工程と、その粉末成型品の前記第１の位置とは異なる第２の位置の温度を計測する第２計測工程とを有し、
前記第１計測工程及び前記第２計測工程での計測結果が共に前記蒸発温度に達する前に、前記炉内の温度を、前記蒸発温度において所定時間保持する第２保持工程を有する請求項１または２に記載の脱脂方法。 A first measurement step of measuring a temperature of the first position of the powder molded product, and a second measurement step of measuring a temperature of a second position different from the first position of the powder molded product. ,
2. A second holding step for holding the temperature in the furnace at the evaporation temperature for a predetermined time before both the measurement results in the first measurement step and the second measurement step reach the evaporation temperature. 2. The degreasing method according to 2. - 前記第２保持工程に移行する前に、前記炉内の温度を、前記蒸発温度以上に昇温させる昇温工程を有する請求項３または４に記載の脱脂方法。 The degreasing method according to claim 3 or 4, further comprising a temperature raising step of raising the temperature in the furnace to the evaporation temperature or higher before shifting to the second holding step.
- 前記炉内の雰囲気圧力を調節する圧力調節工程を有する請求項１～５のいずれか一項に記載の脱脂方法。 The degreasing method according to any one of claims 1 to 5, further comprising a pressure adjusting step of adjusting an atmospheric pressure in the furnace.
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|---|---|---|---|
| KR1020127019272A KR101453463B1 (en) | 2009-12-28 | 2010-12-24 | Degreasing method |
| RU2012131948/02A RU2518825C2 (en) | 2009-12-28 | 2010-12-24 | Method of wax removal |
| CN201080059431.5A CN102655967B (en) | 2009-12-28 | 2010-12-24 | Degreasing method |
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| JP2009297251A JP5492550B2 (en) | 2009-12-28 | 2009-12-28 | Degreasing method |
| JP2009-297251 | 2009-12-28 |
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| JP (1) | JP5492550B2 (en) |
| KR (1) | KR101453463B1 (en) |
| CN (1) | CN102655967B (en) |
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| CN102528041A (en) * | 2012-02-27 | 2012-07-04 | 宝得粉末注射成形（常熟）有限公司 | Energy-saving degreasing device |
| CN102528042A (en) * | 2012-02-27 | 2012-07-04 | 宝得粉末注射成形（常熟）有限公司 | Siphon-type degreasing furnace |
| CN102581283A (en) * | 2012-02-27 | 2012-07-18 | 宝得粉末注射成形（常熟）有限公司 | Siphon type degreasing and pre-sintering device |
| CN115007540A (en) * | 2022-04-28 | 2022-09-06 | 中国航发南方工业有限公司 | Dewaxing method for complex cavity part |
| CN115007540B (en) * | 2022-04-28 | 2024-05-10 | 中国航发南方工业有限公司 | Dewaxing method for complex cavity parts |
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| TWI556909B (en) * | 2011-12-01 | 2016-11-11 | 鴻海精密工業股份有限公司 | Device for automatically removing wax and mothod for same |
| JP5942537B2 (en) * | 2012-03-29 | 2016-06-29 | セイコーエプソン株式会社 | Method for producing degreased body and method for producing sintered body |
| JP6607368B2 (en) * | 2014-12-18 | 2019-11-20 | 大同特殊鋼株式会社 | Continuous vacuum sintering equipment |
| CN104984949A (en) * | 2015-06-09 | 2015-10-21 | 上海鸿辉光通科技股份有限公司 | Wax removing washing method for V groove |
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Also Published As
| Publication number | Publication date |
|---|---|
| CN102655967B (en) | 2014-12-24 |
| KR101453463B1 (en) | 2014-10-22 |
| JP2011137202A (en) | 2011-07-14 |
| RU2012131948A (en) | 2014-02-10 |
| TWI422445B (en) | 2014-01-11 |
| RU2518825C2 (en) | 2014-06-10 |
| TW201132427A (en) | 2011-10-01 |
| CN102655967A (en) | 2012-09-05 |
| JP5492550B2 (en) | 2014-05-14 |
| KR20120108017A (en) | 2012-10-04 |
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