JP2007138223A

JP2007138223A - Method and apparatus for die-quenching ring type article

Info

Publication number: JP2007138223A
Application number: JP2005331549A
Authority: JP
Inventors: Atsushi Yoshitomi; 淳吉富; Kenji Tamada; 健治玉田
Original assignee: NTN Corp; NTN Toyo Bearing Co Ltd
Current assignee: NTN Corp
Priority date: 2005-11-16
Filing date: 2005-11-16
Publication date: 2007-06-07

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and an apparatus for die-quenching a ring type article with which the die-quenching having little thermal-deformation and good precision to the circularity etc. can be performed by precisely performing the centering of the ring type article and this method can be applied to the plurality of kinds of ring type articles having different sizes. <P>SOLUTION: The die-quenching method for ring type article, contains: a heating process for heating the ring type article 10 to the quenching temperature; and a cooling process for cooling under state of pressing restrictive dies 11U, 11L against the contacting surface 11 dividing into the plurality of contacting positions in the peripheral direction while inclining so as to approach to the other peripheral edge side with the increase of separation distance from the ring type article 10 in the axial direction to the one side of the peripheral edge between the outer peripheral edge and the inner peripheral edge on both surfaces of the ring type article 10. The die-quenching apparatus is provided with an upper/lower die holding means which can hold the restrictive dies 11U, 11L so as to press against the peripheral edges of the upper/lower side surfaces of the ring type article whose both surfaces direct the upper and the lower sides. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

この発明は、拘束型を用いて軸受軌道輪等のリング状品を焼入れするリング状品の型焼入れ方法および装置に関する。 The present invention relates to a ring quenching method and apparatus for quenching a ring-shaped product such as a bearing race using a constraining die.

軸受の軌道輪等のようなリング状品を焼入れする際、熱変形の防止や真円度の調整のために、図７に示すように、リング状品１０を円筒状の拘束型１３に入れて冷却することが行われている。詳しくは、リング状品１０を焼入れ温度（８５０℃程度）まで加熱した後、マルテンサイト変態点（２３０℃）付近の温度までは型拘束しない状態で冷却し、同温度まで低下した時点でリング状品１０を拘束型１３に入れ、その状態のまま一定温度（１１０℃程度）まで冷却し、同温度まで冷却したなら拘束型１３からリング状品１０を取り出し、その後は常温まで自然冷却させる。
このような冷却の仕方をする理由は、図８のグラフによって説明することができる。すなわち、ＳＵＪ材等の軸受鋼は、焼入れ温度まで加熱した後、急速冷却した場合、マルテンサイト変態点Ｍｓまでは収縮するが、マルテンサイト変態点Ｍｓ以下になると膨張するという特徴がある。したがって、マルテンサイト変態点Ｍｓ付近でリング状品を型拘束することにより、それ以下に冷却されるのに伴ってリング状品が膨張して拘束型に押し付けられて、拘束型の形状と同一になるよう塑性変形する。このため、熱変形の少ない所定の形状および寸法が得られるのである。 When quenching a ring-shaped product such as a bearing ring, a ring-shaped product 10 is placed in a cylindrical constraining die 13 as shown in FIG. 7 in order to prevent thermal deformation and adjust the roundness. Cooling is done. Specifically, after the ring-shaped product 10 is heated to the quenching temperature (about 850 ° C.), it is cooled to a temperature near the martensite transformation point (230 ° C.) without being constrained, and when the temperature decreases to the same temperature, the ring shape The product 10 is put into the constraining die 13 and cooled to a certain temperature (about 110 ° C.) in that state. When the product is cooled to the same temperature, the ring-like product 10 is taken out from the constraining die 13 and then naturally cooled to room temperature.
The reason for such a cooling method can be explained by the graph of FIG. That is, when the bearing steel such as SUJ material is heated to the quenching temperature and then rapidly cooled, it contracts to the martensite transformation point Ms, but expands when the martensite transformation point Ms is reached. Therefore, by constraining the ring-shaped product in the vicinity of the martensite transformation point Ms, the ring-shaped product expands and is pressed against the constraining die as it is cooled below it, so that it is the same as the shape of the constraining die. The plastic deformation is performed. For this reason, the predetermined shape and dimension with little thermal deformation are obtained.

しかし、上記方法で焼入れした場合、リング状品は膨張して拘束型にぴったりと嵌っているため、焼入れ終了後に拘束型からリング状品を分離して取り出すのが容易ではない。実際には、リング状品をパンチで軸方向の打撃を加えて拘束型から取り出すようにしているが、この作業は手間のかかるものである。また、径方向に完全に拘束されているため、型焼入れ時にリング状品に内部歪みが生じ、それが端面部の反り（図７にＡで示す）となって現れやすい。 However, when quenched by the above method, the ring-shaped product expands and fits tightly into the constraining mold, so it is not easy to separate the ring-shaped product from the constraining mold after quenching. Actually, the ring-shaped product is removed from the constraining die by hitting it in the axial direction with a punch, but this operation is time-consuming. Further, since the ring-shaped product is completely constrained in the radial direction, internal distortion occurs in the ring-shaped product, which tends to appear as a warp of the end surface portion (indicated by A in FIG. 7).

そこで、拘束型として軸方向に長い縦型円筒状のものを用い、この縦型円筒状の拘束型に対して上側から順にリング状品を押し込み、それによって型内のリング状品が下側から順に押し出されるようにし、型内に滞留している間にリング状品が冷却される構成とする提案が特許文献１に記載されている。この構成とすれば、拘束型からリング状品を取り出す作業が不要で、リング状品の焼入れと取り出しを連続して行うことができる。また、径方向の拘束が緩やかであるので、端面部の反りも現れにくい。 Therefore, a vertical cylindrical shape that is long in the axial direction is used as the constraining die, and the ring-shaped product is pushed into the vertical cylindrical constraining die in order from the upper side. Patent Document 1 discloses a proposal in which the ring-shaped product is cooled while being pushed out in order and staying in the mold. With this configuration, it is not necessary to take out the ring-shaped product from the constraining die, and the ring-shaped product can be quenched and taken out continuously. Further, since the radial restraint is moderate, the end face is less likely to warp.

また、他の試案として、拘束型の有効径を変更可能とし、型拘束して焼入れした後に拘束型の有効径を広げることにより、リング状品を拘束型から容易に取り出せるようにすることが考えられている。
特開平０９−１７６７４０号公報 Also, as another tentative plan, it is possible to change the effective diameter of the constraining mold and to allow the ring-shaped product to be easily taken out from the constraining mold by expanding the effective diameter of the constraining mold after quenching by mold constraining. It has been.
JP 09-176740 A

しかし、特許文献１の提案例は、拘束型とリング状品との摩擦力によってリング状品が型内に保持されるようになっているため、大きなリング状品の場合は自重で拘束型から落下してしまう可能性がある。また、拘束型へのリング状品の押し込みと取り出しが連続して行われるため、少量生産のリング状品の製造には不向きである。したがって、この提案例は、大量に生産する比較的小さなリング状品という特殊な条件の場合にだけ適用することができ、リング状品全般の焼入れに適用できるものではない。 However, in the proposed example of Patent Document 1, the ring-shaped product is held in the mold by the frictional force between the constraining mold and the ring-shaped product. There is a possibility of falling. Further, since the ring-shaped product is continuously pushed into and taken out from the constraining mold, it is not suitable for manufacturing a small-volume production of the ring-shaped product. Therefore, this proposed example can be applied only in the case of a special condition of a relatively small ring-shaped product produced in large quantities, and cannot be applied to quenching of ring-shaped products in general.

一方、前記試案の場合は、拘束型の有効径を変更するための機構を必要とし、また型焼入れ中に拘束型の有効径が変更してしまわないように圧力をかけておく必要があり、この圧力として数１０トンないし１００トンを超える荷重負荷が必要なため、装置が大型化するとともに、運転コストが高くなることが考えられる。 On the other hand, in the case of the tentative plan, a mechanism for changing the effective diameter of the constraining mold is required, and it is necessary to apply pressure so that the effective diameter of the constraining mold does not change during mold quenching. Since this pressure requires a load load exceeding several tens tons to 100 tons, it is conceivable that the apparatus becomes larger and the operating cost becomes higher.

この発明の目的は、比較的簡単な作業手順および構成でありながら、リング状品の芯出しを正確に行えて、熱変形が少なく、かつ真円度等につき精度の良い型焼入れを行うことができ、しかもサイズの異なる複数種のリング状品に適用できるリング状品の型焼入れ方法および装置を提供することである。 An object of the present invention is to accurately perform die quenching with a high degree of accuracy with respect to roundness, etc. while accurately aligning a ring-shaped product, with less heat deformation, and with a relatively simple work procedure and configuration. Another object of the present invention is to provide a method and apparatus for quenching a ring-shaped product that can be applied to a plurality of types of ring-shaped products having different sizes.

この発明のリング状品の型焼入れ方法は、リング状品を焼入れ温度まで加熱する加熱過程と、リング状品の両面における外周縁および内周縁のうちの一方の周縁に、リング状品との接触面がリング状品から軸方向に離れるに従って他方の周縁側に近づくように傾き、かつ前記接触面が周方向に複数の接触箇所に分割された拘束型を押し当てた状態で冷却する冷却過程とを含むことを特徴とする。 The mold quenching method for a ring-shaped product according to the present invention includes a heating process for heating the ring-shaped product to a quenching temperature, and contact with the ring-shaped product on one of the outer peripheral edge and the inner peripheral edge on both sides of the ring-shaped product. A cooling process in which the surface is tilted so as to approach the other peripheral side as it is separated from the ring-shaped product in the axial direction, and the contact surface is cooled in a state of pressing a constraining die divided into a plurality of contact locations in the circumferential direction; It is characterized by including.

この方法によると、焼入れ温度まで加熱されたリング状品を冷却する際に、リング状品の周縁に上記のように接触面が傾いた拘束型が押し当てられるため、リング状品は、軸方向への伸びおよび径方向への拡張を拘束された状態で冷却されることとなり、両方向への熱変形が抑えられて、真円度および平坦度につき精度良く焼入れが行われる。ただし、両方向への変形を完全に拘束しているのではなく、若干の変形は許容しているため、内部歪み等が生じにくく、端面部の反りも少ない。また、リング状品との接触面が周方向に複数の接触箇所に分割されているという拘束型の形状を利用し、拘束型の内周側にリング状品の芯出し用の部材を設置することができる。これにより、リング状品の芯出しが確実なものとなり、より一層真円度の精度が良い焼入れを行うことができる。焼入れ終了後、上下の拘束型を互いに離間させるだけで、拘束型からリング状品を簡単に取り出すことができる。
この型焼入れ方法は、リング状品の周縁を拘束型の接触面により線で拘束するものであるため、拘束型の接触面のいずれかの部分をリング状品の周縁に押し当てることができれば良い。したがって、拘束型の接触面の範囲内であれば、サイズの異なる複数種のリング状品に使用することができる。また、拘束型とリング状品とが線で接触するため、拘束型がリング状品からの熱の影響を受けにくく、拘束型の耐久性が良い。
拘束型をリング状品に押し当てる圧力は、拘束状態を維持できる程度あればよく、さほど大きくする必要がない。このため、拘束型および拘束型を支持する部材の自重を前記圧力として利用することができ、拘束型をリング状品に押し当てる機構を簡略なものとすることができる。 According to this method, when the ring-shaped product heated to the quenching temperature is cooled, the constraining mold with the contact surface inclined as described above is pressed against the periphery of the ring-shaped product. Thus, cooling is performed in a state in which the expansion and the expansion in the radial direction are constrained, the thermal deformation in both directions is suppressed, and the roundness and the flatness are quenched with high accuracy. However, the deformation in both directions is not completely constrained, but a slight deformation is allowed. Therefore, internal distortion or the like hardly occurs, and the end face is less warped. Also, using a constraining shape in which the contact surface with the ring-shaped product is divided into a plurality of contact locations in the circumferential direction, a member for centering the ring-shaped product is installed on the inner peripheral side of the constraining die be able to. As a result, centering of the ring-shaped product is ensured, and quenching with higher roundness accuracy can be performed. After quenching is completed, the ring-shaped product can be easily removed from the constraining mold by simply separating the upper and lower constraining molds from each other.
In this mold hardening method, the peripheral edge of the ring-shaped product is constrained by a line by the constraining mold contact surface, so any part of the constraining mold contact surface may be pressed against the peripheral edge of the ring-shaped product. . Therefore, as long as it is within the range of the constraining contact surface, it can be used for a plurality of types of ring-shaped products having different sizes. In addition, since the constraining die and the ring-shaped product are in contact with each other with a line, the constraining die is not easily affected by heat from the ring-shaped product, and the durability of the constraining die is good.
The pressure for pressing the constraining die against the ring-shaped product is only required to maintain the constrained state, and does not need to be increased so much. For this reason, the self-weight of the restraint mold and the member supporting the restraint mold can be used as the pressure, and the mechanism for pressing the restraint mold against the ring-shaped product can be simplified.

前記拘束型は一体のリング状のものとすることができる。拘束型が一体のリング状であると、拘束型の取扱が容易である。
また、前記リング状品は軸受の軌道輪とすることができる。 The constraining mold may be an integral ring. When the constraining die is an integral ring shape, handling of the constraining die is easy.
The ring-shaped product may be a bearing race.

この発明のリング状品の型焼入れ方法において、リング状品の両面における外周縁に拘束型を押し当てる場合に用いる拘束型は、リング状品との接触面が、リング状品から軸方向に離れるに従ってリング状品の内周縁側に近づくように傾き、かつ周方向に複数の接触箇所に分割されているものとする。また、リング状品の両面における内周縁に拘束型を押し当てる場合に用いる拘束型は、リング状品との接触面が、リング状品から軸方向に離れるに従ってリング状品の外周縁側に近づくように傾き、かつ周方向に複数の接触箇所に分割されているものとする。 In the mold quenching method for a ring-shaped product according to the present invention, the constraining die used when pressing the constraining die against the outer peripheral edges of both surfaces of the ring-shaped product is such that the contact surface with the ring-shaped product is separated from the ring-shaped product in the axial direction. Accordingly, it is inclined so as to approach the inner peripheral edge side of the ring-shaped product and is divided into a plurality of contact locations in the circumferential direction. The restraint die used when pressing the restraint die against the inner periphery of both sides of the ring-shaped product is such that the contact surface with the ring-shaped product approaches the outer peripheral edge of the ring-shaped product as it moves away from the ring-shaped product in the axial direction. And is divided into a plurality of contact locations in the circumferential direction.

また、この発明のリング状品の型焼入れ装置は、リング状品を焼入れ温度まで加熱する加熱部と、この加熱部によって加熱されたリング状品の両面における外周縁および内周縁のうちの一方の周縁に、リング状品との接触面がリング状品から軸方向に離れるに従って他方の周縁側に近づくように傾き、かつ前記接触面が周方向に複数の接触箇所に分割された拘束型を押し当てた状態で冷却する冷却部とを備え、前記冷却部は、両面が上下を向いたリング状品の上側面の前記周縁に前記接触面を押し当てるように前記拘束型を保持することのできる上型保持手段と、同リング状品の下側面の前記周縁に前記接触面を押し当てるように前記拘束型を保持することのできる下型保持手段と、上型・下型両保持手段の中心を同心に維持する同心維持手段とを有することを特徴とする。 The mold quenching apparatus for a ring-shaped product according to the present invention includes a heating unit that heats the ring-shaped product to a quenching temperature, and one of the outer peripheral edge and the inner peripheral edge on both surfaces of the ring-shaped product heated by the heating unit. Push the constraining die that is inclined so that the contact surface with the ring-shaped product is closer to the other peripheral side as it is axially separated from the ring-shaped product, and the contact surface is divided into a plurality of contact locations in the circumferential direction. A cooling part that cools in a contact state, and the cooling part can hold the constraining die so that the contact surface is pressed against the peripheral edge of the upper side surface of the ring-shaped product with both surfaces facing up and down. Upper mold holding means, lower mold holding means capable of holding the constraining mold so that the contact surface is pressed against the peripheral edge of the lower side surface of the ring-shaped product, and the center of both the upper mold and lower mold holding means Concentricity keeping hands concentric Characterized in that it has and.

この発明のリング状品の型焼入れ装置によれば、加熱部によってリング状品を焼入れ温度まで加熱し、その加熱されたリング状品を、冷却部によって、両面における外周縁および内周縁のうちの一方の周縁に、リング状品から軸方向に離れるに従って他方の周縁側に近づくようにリング状品との接触面が傾く拘束型を押し当てた状態で冷却する。冷却部でリング状品を冷却する際には、両面が上下を向いたリング状品の上側面の周縁に、上型保持手段に保持された上型を押し当てるとともに、同リング状品の下側面の周縁に、下型保持手段に保持された下型を押し当てる。このとき、同心維持手段により上型・下型両保持手段の中心を同心に維持すると同時に、拘束型の内周側に設置された芯出し用の部材でリング状品の芯出しを行うことにより、リング状品の芯出しを確実なものとして、リング状品の真円度を高めることができる。冷却部を上記構成とすることにより、冷却部による冷却過程の作業能率を向上させることができる。 According to the mold quenching apparatus for a ring-shaped product of the present invention, the ring-shaped product is heated to the quenching temperature by the heating unit, and the heated ring-shaped product is cooled by the cooling unit among the outer peripheral edge and the inner peripheral edge on both sides. Cooling is performed in a state in which a constraining die whose contact surface with the ring-shaped product is inclined so as to approach the other peripheral side as it is separated from the ring-shaped product in the axial direction is pressed on one peripheral edge. When cooling the ring-shaped product in the cooling section, press the upper mold held by the upper mold holding means against the peripheral edge of the upper surface of the ring-shaped product with both sides facing up and down, The lower mold held by the lower mold holding means is pressed against the peripheral edge of the side surface. At this time, by maintaining the center of both the upper and lower mold holding means concentrically by the concentricity maintaining means, at the same time by centering the ring-shaped product with the centering member installed on the inner peripheral side of the restraint type The roundness of the ring-shaped product can be increased by ensuring the centering of the ring-shaped product. By setting the cooling unit to the above configuration, it is possible to improve the work efficiency of the cooling process by the cooling unit.

この発明のリング状品の型焼入れ方法は、リング状品を焼入れ温度まで加熱する加熱過程と、リング状品の両面における外周縁および内周縁のうちの一方の周縁に、リング状品との接触面がリング状品から軸方向に離れるに従って他方の周縁側に近づくように傾き、かつ前記接触面が周方向に複数の接触箇所に分割された拘束型を押し当てた状態で冷却する冷却過程とを含むものとしたため、比較的簡単な作業手順でありながら、リング状品の芯出しを正確に行えて、熱変形が少なく、真円度等の精度の良い型焼入れを行うことができ、しかもサイズの異なる複数種のリング状品に適用できる優れた方法となった。
また、この発明のリング状品の型焼入れ装置は、リング状品を焼入れ温度まで加熱する加熱部と、この加熱部によって加熱されたリング状品の両面における外周縁および内周縁のうちの一方の周縁に、リング状品との接触面がリング状品から軸方向に離れるに従って他方の周縁側に近づくように傾き、かつ前記接触面が周方向に複数の接触箇所に分割されたく拘束型を押し当てた状態で冷却する冷却部とを備え、前記冷却部は、両面が上下を向いたリング状品の上側面の前記周縁に押し当てるように前記拘束型を保持することのできる上型保持手段と、同リング状品の下側面の前記周縁に前記接触面を押し当てるように前記拘束型を保持することのできる下型保持手段と、上型・下型両保持手段の中心を同心に維持する同心維持手段とを有するものとしたため、比較的簡単な構成でありながら、リング状品の芯出しを正確に行えて、熱変形が少なく、真円度等の精度の良い型焼入れを行うことができ、しかもサイズの異なる複数種のリング状品に適用できる優れた装置となった。 The mold quenching method for a ring-shaped product according to the present invention includes a heating process for heating the ring-shaped product to a quenching temperature, and contact with the ring-shaped product on one of the outer peripheral edge and the inner peripheral edge on both sides of the ring-shaped product. A cooling process in which the surface is tilted so as to approach the other peripheral side as it is separated from the ring-shaped product in the axial direction, and the contact surface is cooled in a state of pressing a constraining die divided into a plurality of contact locations in the circumferential direction; The ring-shaped product can be accurately centered with less heat deformation and accurate mold quenching such as roundness, etc., although it is a relatively simple work procedure. It became an excellent method applicable to multiple types of ring-shaped products with different sizes.
The mold quenching apparatus for a ring-shaped product according to the present invention includes a heating unit that heats the ring-shaped product to a quenching temperature, and one of the outer peripheral edge and the inner peripheral edge on both surfaces of the ring-shaped product heated by the heating unit. Push the constraining die at the periphery so that the contact surface with the ring-shaped product is inclined so as to approach the other peripheral side as it moves away from the ring-shaped product in the axial direction, and the contact surface is divided into a plurality of contact locations in the circumferential direction. An upper mold holding means capable of holding the constraining mold so as to press against the peripheral edge of the upper side surface of the ring-shaped product with both surfaces facing up and down. A lower mold holding means capable of holding the constraining mold so that the contact surface is pressed against the peripheral edge of the lower side surface of the ring-shaped product, and maintaining the centers of both the upper mold and the lower mold holding means concentrically. With concentricity maintenance means Because it is a relatively simple structure, ring-shaped products can be accurately centered, thermal deformation is small, and precision quenching such as roundness can be performed, and the sizes are different. It became an excellent device applicable to multiple types of ring-shaped products.

この発明の実施形態を図と共に説明する。このリング状品の型焼入れ装置１は、図１に示すように、加熱部２、一次冷却部３、二次冷却部４、空冷部５、洗浄部６および焼戻し部７よりなる。
加熱部２は、加熱炉を用いてリング状品を所定の焼入れ温度（例えば８５０℃）まで加熱する。この過程を加熱過程という。
一次冷却部３は、焼入れ温度まで加熱されたリング状品を、型拘束しない状態のまま油中に浸漬して、マルテンサイト変態点付近（例えば２７０℃）まで一次冷却する。二次冷却部４は、一次冷却されたリング状品を、拘束型に型入れした状態で油中に浸漬して、一定温度（例えば１１０℃）まで二次冷却する。一次冷却と二次冷却を合わせて冷却過程という。
冷却過程終了後、リング状品は、空冷部５で常温まで自然冷却され、洗浄部６で洗浄され、焼戻し部７で焼戻し処理される。 An embodiment of the present invention will be described with reference to the drawings. As shown in FIG. 1, the ring-shaped product quenching apparatus 1 includes a heating unit 2, a primary cooling unit 3, a secondary cooling unit 4, an air cooling unit 5, a cleaning unit 6, and a tempering unit 7.
The heating unit 2 heats the ring-shaped product to a predetermined quenching temperature (for example, 850 ° C.) using a heating furnace. This process is called a heating process.
The primary cooling unit 3 immerses the ring-shaped product heated to the quenching temperature in oil without being mold-constrained, and performs primary cooling to the vicinity of the martensitic transformation point (for example, 270 ° C.). The secondary cooling unit 4 immerses the primary-cooled ring-shaped product in oil in a state where it is placed in a constraining mold, and performs secondary cooling to a certain temperature (for example, 110 ° C.). The primary cooling and the secondary cooling are collectively referred to as a cooling process.
After completion of the cooling process, the ring-shaped product is naturally cooled to room temperature by the air cooling unit 5, cleaned by the cleaning unit 6, and tempered by the tempering unit 7.

この型焼入れ装置１の特徴は、二次冷却部４での型焼入れ方法に有る。その型焼入れ方法とは、リング状品の両面における外周縁および内周縁のうちの一方の周縁に、リング状品との接触面がリング状品から軸方向に離れるに従って他方の周縁側に近づくように傾き、かつ前記接触面が周方向に複数の接触箇所に分割された拘束型を押し当てた状態で冷却するというものである。ここで、「傾く」というのは、リング状品との接触面のことであり、拘束型全体の形状や拘束型をリング状品に押し当てるために加圧する方向のことではない。 A feature of the mold quenching apparatus 1 is a mold quenching method in the secondary cooling unit 4. The mold quenching method is such that one of the outer peripheral edge and the inner peripheral edge on both surfaces of the ring-shaped product is brought closer to the other peripheral side as the contact surface with the ring-shaped product moves away from the ring-shaped product in the axial direction. And cooling with the contact surface pressed against a constraining die divided into a plurality of contact locations in the circumferential direction. Here, “inclined” refers to the contact surface with the ring-shaped product, not the shape of the entire constraining mold or the direction in which pressure is applied to press the constraining mold against the ring-shaped product.

図２は二次冷却部４で使用される拘束型を示す。この拘束型１１は、リング状部１１ａの内周に複数の接触部１１ｂが互いに等間隔で形成されたものであり、接触部１１ｂの上下一方の面は拘束型１１の上下端面に対して傾いた接触面１１ｃとなっている。各接触部１１ｂの接触面１１ｃは、共通の円すい面上に位置している。接触面１１ｃの角度θは、通常は４５°とされるが、これに限らない。接触面１１ｃの角度θの違いにより、型焼入れ時の変形防止効果に若干の違いがある。つまり、角度θが大きい場合は、径方向への変形を防止して真円度を高める効果が大きく、角度θが小さい場合は、反りを抑えて平坦度を高める効果が大きいという傾向がある。 FIG. 2 shows a restraint type used in the secondary cooling unit 4. In the constraining die 11, a plurality of contact portions 11b are formed at equal intervals on the inner periphery of the ring-shaped portion 11a. One of the upper and lower surfaces of the contact portion 11b is inclined with respect to the upper and lower end surfaces of the constraining die 11. The contact surface 11c is formed. The contact surface 11c of each contact part 11b is located on a common conical surface. The angle θ of the contact surface 11c is normally 45 °, but is not limited thereto. Due to the difference in the angle θ of the contact surface 11c, there is a slight difference in the deformation preventing effect during mold hardening. That is, when the angle θ is large, the effect of preventing the deformation in the radial direction and increasing the roundness is large, and when the angle θ is small, the effect of suppressing the warpage and increasing the flatness tends to be large.

型焼入れ時におけるリング状品および拘束型の状態を図３に示す。図で符合１０はリング状品であり、この例では軸受の外輪とされている。このリング状品１０の上下両側に、前記拘束型１１が上型１１Ｕおよび下型１１Ｌとして設けられ、その接触面１１ｃがリング状品１０の上下両端面の外周縁に押し当てられている。接触面１１ｃはリング状品１０の外周面１０ａに対して傾いているため、上型１１Ｕおよび下型１１Ｌとリング状品１０とは線で接触する。 FIG. 3 shows the state of the ring-shaped product and the constraining die during mold quenching. In the figure, reference numeral 10 denotes a ring-shaped product, which is an outer ring of a bearing in this example. The constraining die 11 is provided as an upper die 11U and a lower die 11L on both the upper and lower sides of the ring-shaped product 10, and the contact surfaces 11c are pressed against the outer peripheral edges of the upper and lower end surfaces of the ring-shaped product 10. Since the contact surface 11c is inclined with respect to the outer peripheral surface 10a of the ring-shaped product 10, the upper mold 11U and the lower mold 11L and the ring-shaped product 10 are in contact with each other by a line.

図４はリング状品が軸受の内輪である例を示している。この場合、このリング状品１０の上下両側に設けられた上型１２Ｕおよび下型１２Ｌの接触面１２ｃが、リング状品１０の上下両端面の内周縁に押し当てられる。この拘束型１２も、上記同様に、リング状部１１ａの内周に複数の接触部１１ｂが互いに等間隔で形成されたものである。拘束型１２の接触面１２ｃはリング状品１０の内周面１０ａに対して傾いていて、上型１２Ｕおよび下型１２Ｌとリング状品１０とは線で接触する。 FIG. 4 shows an example in which the ring-shaped product is an inner ring of a bearing. In this case, the contact surfaces 12c of the upper mold 12U and the lower mold 12L provided on both the upper and lower sides of the ring-shaped product 10 are pressed against the inner peripheral edges of the upper and lower end surfaces of the ring-shaped product 10. Similarly to the above, this constraining die 12 is also formed with a plurality of contact portions 11b formed at equal intervals on the inner periphery of the ring-shaped portion 11a. The contact surface 12c of the constraining mold 12 is inclined with respect to the inner peripheral surface 10a of the ring-shaped product 10, and the upper mold 12U and the lower mold 12L and the ring-shaped product 10 are in contact with each other by a line.

上記のように拘束型をリング状品に押し当てるために、図５に示す型押し当て機構が用いられる。図はリング状品１０が軸受の外輪である場合を示している。この型押し当て機構２０は、下型取付ベース２１に複数本の昇降ガイド２２が鉛直方向に立設され、この昇降ガイド２２に沿って上型取付ベース２３が摺動自在に設けられている。なお、各昇降ガイド２２の上端は連結板２４により互いに連結されている。上型取付ベース２３は、その下面に上型１１Ｕがボルト等により取付けられるものであって、上型保持手段となっている。また、下型取付ベース２１は、その上面に下型１１Ｌがボルト等により取付けられるものであって、下型保持手段となっている。上型取付ベース２３には昇降ロッド２６が連結されており、この昇降ロッド２６を図示しない昇降駆動源により上下動させることにより、上型取付ベース２３を昇降ガイド２２に沿って昇降させるようになっている。昇降ガイド２２は、上型・下型両保持手段２３，２１の中心を同心に維持する同心維持手段となっている。 In order to press the constraining die against the ring-shaped product as described above, the die pressing mechanism shown in FIG. 5 is used. The figure shows a case where the ring-shaped product 10 is an outer ring of a bearing. In the mold pressing mechanism 20, a plurality of lifting guides 22 are vertically provided on a lower mold mounting base 21, and an upper mold mounting base 23 is slidably provided along the lifting guide 22. Note that the upper ends of the elevating guides 22 are connected to each other by a connecting plate 24. The upper mold attaching base 23 is an upper mold holding means for attaching the upper mold 11U to the lower surface thereof with bolts or the like. The lower mold mounting base 21 has a lower mold 11L attached to the upper surface thereof with bolts or the like, and serves as a lower mold holding means. A lifting rod 26 is connected to the upper mold mounting base 23, and the upper mold mounting base 23 is moved up and down along the lifting guide 22 by moving the lifting rod 26 up and down by a lifting drive source (not shown). ing. The elevating guide 22 is a concentricity maintaining means for maintaining the centers of the upper and lower mold holding means 23 and 21 concentrically.

一次冷却部３で一次冷却されたリング状品１０が上型１１Ｕと下型１１Ｌの間に供給されると、下型１１Ｌに対して上型１１Ｕが下降してきて、両拘束型１１Ｕ，１１Ｌによりリング状品１０を拘束する。このとき、上型１１Ｕの一度の下降動作でリング状品１０を拘束するのではなく、上型１１Ｕは、下降してきてリング状品１０に当ると一旦浮上するという動作を数回（例えば3回）繰り返してから、正規にリング状品１０を拘束する。このような動作を行うことにより、リング状品１０が供給された段階では拘束型１１Ｕ，１１Ｌとリング状品１０との間に位置関係のわずかなズレがあった場合でも、そのズレを無くして拘束型１１Ｕ，１１Ｌとリング状品１０とが緊密に接触する状態、いわゆる馴染んだ状態とすることができる。これにより、リング状品１０芯出しが行われる。
また、図５において２点鎖線で示すように、リング状品１０の内周縁にテーパ面が当接するように芯出し部材２８を設けておくと、リング状品１０の芯出しをより一層精度良く行うことができる。芯出し部材２８の平面形状は、例えば図２（Ａ）において２点鎖線で示すような形状とすることができる。放射状に延びる板状部２８ａの上面が、テーパ面とされている。芯出し部材２８をこの形状とした場合、上記板状部２８ａを下型１１Ｌの接触部１１ｂ間の空間に位置させることにより、下型１１Ｌの内側に芯出し部材２８を配置することが可能となる。
拘束型１１Ｕ，１１Ｌに拘束されたリング状品１０は、上型１１Ｕおよび上型取付ベース２３の自重で拘束型１１Ｕ，１１Ｌをリング状品１０の上下の外周縁に押し当てる状態で油中に浸漬され、２６０℃程度から１１０℃程度にまで冷却される。 When the ring-shaped product 10 that has been primarily cooled by the primary cooling unit 3 is supplied between the upper mold 11U and the lower mold 11L, the upper mold 11U descends with respect to the lower mold 11L, and the both molds 11U and 11L The ring-shaped product 10 is restrained. At this time, the upper mold 11U does not restrain the ring-shaped article 10 by a single lowering operation, but the upper mold 11U moves several times (for example, three times) when it descends and hits the ring-shaped article 10 once. ) After repeating, the ring-shaped product 10 is properly restrained. By performing such an operation, even if there is a slight positional relationship between the restraining molds 11U and 11L and the ring-shaped product 10 at the stage when the ring-shaped product 10 is supplied, the deviation is eliminated. The restraint molds 11U and 11L and the ring-shaped product 10 can be brought into a close contact state, that is, a so-called familiar state. Thereby, the ring-shaped product 10 is centered.
Further, as shown by a two-dot chain line in FIG. 5, if the centering member 28 is provided so that the tapered surface comes into contact with the inner peripheral edge of the ring-shaped product 10, the centering of the ring-shaped product 10 can be more accurately performed. It can be carried out. The planar shape of the centering member 28 can be, for example, a shape indicated by a two-dot chain line in FIG. The upper surface of the radially extending plate-like portion 28a is a tapered surface. When the centering member 28 has this shape, the centering member 28 can be disposed inside the lower mold 11L by positioning the plate-shaped part 28a in the space between the contact parts 11b of the lower mold 11L. Become.
The ring-shaped product 10 constrained by the constraining dies 11U and 11L is immersed in oil in a state where the restraining dies 11U and 11L are pressed against the upper and lower outer peripheries of the ring-shaped product 10 by the weights of the upper mold 11U and the upper mold mounting base 23. It is immersed and cooled from about 260 ° C. to about 110 ° C.

上記方法で型焼入れを行うと、リング状品１０の周縁に、リング状品１０から軸方向に離れるに従って他方の周縁側に近づくように傾く拘束型１１Ｕ，１１Ｌが押し当てられるため、リング状品１０は、軸方向への伸びおよび径方向への拡張を拘束された状態で冷却されることとなり、両方向への熱変形が抑えられて、真円度および平坦度につき精度良く焼入れが行われる。ただし、両方向への変形を完全に拘束しているのではなく、若干の変形は許容しているため、残留歪み等が生じない。焼入れ終了後、上型１１Ｕを上昇させて上下両型１１Ｕ，１１Ｌを互いに離間させるだけで、拘束型１１Ｕ，１１Ｌからリング状品１０を簡単に取り出すことができる。 When mold hardening is performed by the above method, the restraint dies 11U and 11L that are inclined so as to approach the other peripheral side as they are separated from the ring-shaped product 10 in the axial direction are pressed against the peripheral edge of the ring-shaped product 10. 10 is cooled in a state in which expansion in the axial direction and expansion in the radial direction are constrained, and thermal deformation in both directions is suppressed, and quenching is performed with high accuracy in terms of roundness and flatness. However, the deformation in both directions is not completely constrained, and a slight deformation is allowed, so that no residual distortion occurs. After the quenching is completed, the ring-shaped article 10 can be easily taken out from the restraining dies 11U, 11L by raising the upper die 11U and separating the upper and lower dies 11U, 11L from each other.

この型焼入れ方法は、リング状品１０の周縁を拘束型１１の接触面により線で拘束するものであるため、拘束型１１の接触面１１ｃのいずれかの部分をリング状品の周縁に押し当てることができれば良い。したがって、拘束型１１の接触面１１ｃの範囲内であれば、サイズの異なる複数種のリング状品に使用することができる。また、拘束型１１とリング状品１０とが線で接触するため、拘束型１１がリング状品１０からの熱の影響を受けにくく、拘束型１１の耐久性が良い。
拘束型１１をリング状品１０の上下の外周縁に押し当てる圧力は、拘束状態を維持できる程度あればよく、さほど大きな圧力は必要としない。このため、上型１１Ｕおよび上型取付ベース２３の自重を上記圧力として利用することができ、機構が簡略なものとなっている。 In this mold quenching method, the peripheral edge of the ring-shaped product 10 is constrained by a line by the contact surface of the constraining die 11, so any part of the contact surface 11 c of the constraining die 11 is pressed against the peripheral edge of the ring-shaped product. I hope I can. Therefore, as long as it is within the range of the contact surface 11c of the constraining die 11, it can be used for a plurality of types of ring-shaped products having different sizes. Further, since the constraining die 11 and the ring-shaped product 10 are in contact with each other with a line, the constraining die 11 is hardly affected by the heat from the ring-shaped product 10 and the durability of the constraining die 11 is good.
The pressure for pressing the constraining die 11 against the upper and lower outer peripheries of the ring-shaped product 10 only needs to be sufficient to maintain the constrained state, and does not require much pressure. For this reason, the dead weight of the upper mold | type 11U and the upper mold | type attachment base 23 can be utilized as said pressure, and the mechanism is simple.

この実施の形態では、リング状品と外周縁を拘束型により拘束して型焼入れを行う例を示したが、図４に示す拘束型１２Ｕ，１２Ｌを用いて、リング状品と内周縁を拘束型により拘束して型焼入れを行うこともできる。
また、この実施の形態では、二次冷却において、リング状品を油中に浸漬して冷却するようにしたが、図６に示すように、リング状品１０の外径側および内径側から、リング状品１０に向けて冷却油を噴射して冷却するようにしてもよい。また、外径側および内径側のいずれかだけから冷却油を噴射してもよい。一次冷却についても同様のことが言える。 In this embodiment, the ring-shaped product and the outer peripheral edge are constrained by a constraining die and die quenching is performed. However, the constraining dies 12U and 12L shown in FIG. 4 are used to constrain the ring-shaped product and the inner peripheral edge. Mold quenching can also be performed by restraining the mold.
Further, in this embodiment, in the secondary cooling, the ring-shaped product is immersed and cooled in oil, but as shown in FIG. 6, from the outer diameter side and the inner diameter side of the ring-shaped product 10, You may make it cool by injecting cooling oil toward the ring-shaped article 10. Further, the cooling oil may be injected only from either the outer diameter side or the inner diameter side. The same is true for primary cooling.

この発明の型焼入れ装置の構成を示す図である。It is a figure which shows the structure of the mold hardening apparatus of this invention. （Ａ）は拘束型の平面図、（Ｂ）はそのIIb−IIb断面図である。(A) is a constrained plan view, and (B) is a IIb-IIb sectional view thereof. 拘束型でリング状品の外周縁を拘束した状態を示す断面図である。It is sectional drawing which shows the state which restrained the outer periphery of the ring-shaped article with the restraint type. 拘束型でリング状品の内周縁を拘束した状態を示す断面図である。It is sectional drawing which shows the state which restrained the inner peripheral edge of the ring-shaped article with the restraint type. 型押し当て機構を示す図である。It is a figure which shows a mold pressing mechanism. 二次冷却の方法を示す図である。It is a figure which shows the method of secondary cooling. 従来の型焼入れ方法を示す断面図である。It is sectional drawing which shows the conventional mold hardening method. 焼入れ時の温度と製品長さとの関係を示すグラフである。It is a graph which shows the relationship between the temperature at the time of hardening, and product length.

符号の説明Explanation of symbols

１…型焼入れ装置
２…加熱部
３…一次冷却部
４…二次冷却部
５…空冷部
６…洗浄部
７…焼戻し部
１０…リング状品
１１…拘束型
１１ｃ…接触面
１１Ｕ…上型
１１Ｌ…下型
２０…型押し当て機構
２１…下型取付ベース（下型保持手段）
２２…昇降ガイド（同心維持手段）
２３…上型取付ベース（上型保持手段）
２８…芯出し部材 DESCRIPTION OF SYMBOLS 1 ... Mold hardening apparatus 2 ... Heating part 3 ... Primary cooling part 4 ... Secondary cooling part 5 ... Air cooling part 6 ... Cleaning part 7 ... Tempering part 10 ... Ring-shaped article 11 ... Restraint type 11c ... Contact surface 11U ... Upper mold 11L ... Lower mold 20 ... Mold pressing mechanism 21 ... Lower mold mounting base (lower mold holding means)
22 ... Elevating guide (concentricity maintaining means)
23 ... Upper die mounting base (upper die holding means)
28 ... Centering member

Claims

リング状品を焼入れ温度まで加熱する加熱過程と、リング状品の両面における外周縁および内周縁のうちの一方の周縁に、リング状品との接触面がリング状品から軸方向に離れるに従って他方の周縁側に近づくように傾き、かつ前記接触面が周方向に複数の接触箇所に分割された拘束型を押し当てた状態で冷却する冷却過程とを含むリング状品の型焼入れ方法。 The heating process for heating the ring-shaped product to the quenching temperature, and one of the outer peripheral edge and the inner peripheral edge on both sides of the ring-shaped product, and the other side as the contact surface with the ring-shaped product is separated from the ring-shaped product in the axial direction. A mold quenching method for a ring-shaped product, including a cooling process in which the contact surface is inclined so as to approach the peripheral side of the ring and the contact surface is cooled in a state of pressing a constraining mold divided into a plurality of contact locations in the circumferential direction.

請求項１において、前記拘束型は一体のリング状のものとしたリング状品の型焼入れ方法。 2. The mold quenching method for a ring-shaped product according to claim 1, wherein the constraining mold is an integral ring-shaped mold.

請求項１または請求項２において、前記リング状品は軸受の軌道輪であるリング状品の型焼入れ方法。 3. The die hardening method for a ring-shaped product according to claim 1, wherein the ring-shaped product is a bearing ring.

焼入れ温度まで加熱されたリング状品を冷却して焼入れする際に、リング状品の両面における外周縁に押し当てられる拘束型であって、リング状品との接触面が、リング状品から軸方向に離れるに従ってリング状品の内周縁側に近づくように傾き、かつ周方向に複数の接触箇所に分割されている拘束型。 When the ring-shaped product heated to the quenching temperature is cooled and quenched, it is a restraint type that is pressed against the outer periphery of both sides of the ring-shaped product, and the contact surface with the ring-shaped product is pivoted from the ring-shaped product to the shaft. A constraining die that is inclined so as to approach the inner peripheral edge side of the ring-shaped product as it goes away in the direction, and is divided into a plurality of contact locations in the circumferential direction.

焼入れ温度まで加熱されたリング状品を冷却して焼入れする際に、リング状品の両面における内周縁に押し当てられる拘束型であって、リング状品との接触面が、リング状品から軸方向に離れるに従ってリング状品の外周縁側に近づくように傾き、かつ周方向に複数の接触箇所に分割されている拘束型。 When the ring-shaped product heated to the quenching temperature is cooled and quenched, the constrained type is pressed against the inner periphery of both sides of the ring-shaped product, and the contact surface with the ring-shaped product is pivoted from the ring-shaped product to the shaft. A constraining die that is inclined so as to approach the outer peripheral edge side of the ring-shaped product as it goes away in the direction, and is divided into a plurality of contact locations in the circumferential direction.

リング状品を焼入れ温度まで加熱する加熱部と、この加熱部によって加熱されたリング状品の両面における外周縁および内周縁のうちの一方の周縁に、リング状品との接触面がリング状品から軸方向に離れるに従って他方の周縁側に近づくように傾き、かつ前記接触面が周方向に複数の接触箇所に分割された拘束型を押し当てた状態で冷却する冷却部とを備え、
前記冷却部は、両面が上下を向いたリング状品の上側面の前記周縁に前記接触面を押し当てるように前記拘束型を保持することのできる上型保持手段と、同リング状品の下側面の前記周縁に前記接触面を押し当てるように前記拘束型を保持することのできる下型保持手段と、上型・下型両保持手段の中心を同心に維持する同心維持手段とを有するリング状品の型焼入れ装置。 A heating unit that heats the ring-shaped product to the quenching temperature, and a contact surface with the ring-shaped product is provided on one of the outer peripheral edge and the inner peripheral edge of both surfaces of the ring-shaped product heated by the heating unit. A cooling part that cools in a state in which the contact surface is inclined to approach the other peripheral side as it moves away from the axial direction, and the contact surface is pressed against the constraining die that is divided into a plurality of contact locations in the circumferential direction,
The cooling section includes an upper mold holding means capable of holding the constraining mold so as to press the contact surface against the peripheral edge of the upper side surface of the ring-shaped product with both surfaces facing up and down, and a lower part of the ring-shaped product. A ring having lower mold holding means capable of holding the constraining mold so as to press the contact surface against the peripheral edge of the side surface, and concentricity maintaining means for maintaining the centers of both the upper mold and lower mold holding means concentrically Mold quenching equipment.