JP2014173115A - Spring production method - Google Patents

Spring production method Download PDF

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JP2014173115A
JP2014173115A JP2013045477A JP2013045477A JP2014173115A JP 2014173115 A JP2014173115 A JP 2014173115A JP 2013045477 A JP2013045477 A JP 2013045477A JP 2013045477 A JP2013045477 A JP 2013045477A JP 2014173115 A JP2014173115 A JP 2014173115A
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spring material
spring
heating
electrodes
shape
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Taku Kuramoto
卓 倉本
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Chuo Hatsujo KK
Chuo Spring Co Ltd
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Chuo Hatsujo KK
Chuo Spring Co Ltd
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Abstract

PROBLEM TO BE SOLVED: To provide a technique enabling a heat treatment of a formed spring in a short time.SOLUTION: A spring production method includes a formation step of forming a spring material into a prescribed shape, a restriction step of restricting a plurality of parts of the spring material formed into the prescribed shape to adjust the shape of the spring material, an electrode clamping step of clamping both ends of the spring material formed in the prescribed shape with a pair of electrodes, a release step of releasing the parts restricted in the restriction step without changing the relative positions of the electrodes, after the restriction step and the electrode clamping step and a first heating step of electrifying the spring material through the electrodes to heat the spring material, after the release step.

Description

本明細書は、ばねの製造技術を開示する。詳しくは、ばね材の一端と他端とが離れており、一端と他端の間の少なくとも一箇所において曲げ部を有すると共に、一端と他端の間においてばね材同士が接触していないばね(例えば、線細工ばね、リング状のばね等)を製造するための技術を開示する。   This specification discloses the manufacturing technique of a spring. Specifically, one end and the other end of the spring material are separated from each other, a spring having a bent portion at at least one position between the one end and the other end, and the spring material not contacting between the one end and the other end ( For example, a technique for manufacturing a wirework spring, a ring-shaped spring, or the like) is disclosed.

ばねを製造する際には、種々の熱処理が行われる。例えば、ばね材に生じた加工歪みを除去するために、ばね材が熱処理(いわゆる低温焼鈍し)される。すなわち、ばね材を塑性加工(例えば、曲げ加工等)することで製品形状に成形すると、ばね材には加工歪みが生じる。加工歪みはばね特性(例えば、耐久性、耐へたり性、耐脆性)に悪影響を与えるため、ばね材を製品形状に成形した後に、ばね材に生じた加工歪みを除去するための熱処理が行われる(非特許文献1)。このような熱処理には、通常、熱風炉や赤外線加熱炉のような加熱炉が用いられる。加熱炉を用いて熱処理を行う場合、製品形状に成形されたばね材を加熱炉の一端から加熱炉内に投入する。加熱炉内に投入されたばね材は、加熱炉の他端に向かって搬送されながら加熱され、加熱炉の他端より加熱炉外に搬出される。これによって、ばね材に熱処理が施され、ばね材から加工歪みが除去される。また、加工歪みの除去に伴い、ばねの形状は成形後の寸法から変化する。   When manufacturing the spring, various heat treatments are performed. For example, the spring material is heat-treated (so-called low-temperature annealing) in order to remove processing strain generated in the spring material. That is, if the spring material is formed into a product shape by plastic working (for example, bending), the spring material is strained. Since processing strain adversely affects the spring characteristics (for example, durability, sag resistance, brittleness resistance), after forming the spring material into a product shape, heat treatment is performed to remove the processing strain generated in the spring material. (Non-Patent Document 1). For such heat treatment, a heating furnace such as a hot air furnace or an infrared heating furnace is usually used. When heat treatment is performed using a heating furnace, a spring material formed into a product shape is put into the heating furnace from one end of the heating furnace. The spring material put into the heating furnace is heated while being conveyed toward the other end of the heating furnace, and is carried out of the heating furnace from the other end of the heating furnace. As a result, the spring material is subjected to heat treatment, and processing strain is removed from the spring material. Further, as the processing strain is removed, the shape of the spring changes from the dimension after molding.

日本ばね学会編「ばね」第4版,463〜466ページ,丸善株式会社"Spring" 4th edition, 463-466 pages, edited by the Japan Spring Society, Maruzen Co., Ltd.

ライン生産方式でばねを製造する場合(すなわち、ばねを量産する場合)、ばね材を製品形状に成形する工程が行われると、その成形したばね材は熱処理工程に搬送され、熱処理工程において熱処理が施される。従来の製造方法では、成形工程に要する時間と比較して、熱処理工程に要する時間が長時間となるという問題がある。すなわち、従来の製造方法では、成形工程に要する時間が0.1〜60秒であるのに対して、熱処理工程に要する時間は5〜60分となっている。このため、成形工程に合せてばねを製造すると、熱処理工程には同時に多量のワークが投入されていることとなる。その結果、熱処理用の加熱炉が大型化し、加熱効率が低下してしまうという問題が生じる。   When springs are manufactured by the line production method (that is, when springs are mass-produced), when the process of forming the spring material into a product shape is performed, the formed spring material is transferred to the heat treatment process, and the heat treatment is performed in the heat treatment process. Applied. In the conventional manufacturing method, there is a problem that the time required for the heat treatment process is longer than the time required for the molding process. That is, in the conventional manufacturing method, the time required for the molding process is 0.1 to 60 seconds, whereas the time required for the heat treatment process is 5 to 60 minutes. For this reason, when a spring is manufactured in accordance with the molding process, a large amount of workpieces are simultaneously input into the heat treatment process. As a result, there arises a problem that the heating furnace for heat treatment is enlarged and the heating efficiency is lowered.

本明細書は、ばねに実施する熱処理を短時間で行うことができる技術を提供することを目的とする。   This specification aims at providing the technique which can perform the heat processing implemented to a spring in a short time.

本明細書は、ばね材の一端と他端とが離れており、一端と他端の間の少なくとも一箇所において曲げ部を有すると共に、一端と他端の間においてばね材同士が接触していないばねを製造する方法を開示する。この製造方法は、ばね材を所定形状に成形する成形工程と、所定形状に成形されたばね材の複数個所を拘束して、ばね材の形状を調整する拘束工程と、所定形状に成形されたばね材の両端を一対の電極でクランプする電極クランプ工程と、拘束工程及び電極クランプ工程後に、一対の電極間の相対的位置を変えることなく、拘束工程で拘束された部位を開放する開放工程と、開放工程後に、一対の電極を介してばね材に電流を流すことでばね材を加熱する第1加熱工程を有している。   In the present specification, one end and the other end of the spring material are separated from each other, and there is a bent portion at at least one position between the one end and the other end, and the spring material is not in contact between the one end and the other end. A method of manufacturing a spring is disclosed. This manufacturing method includes a forming step of forming a spring material into a predetermined shape, a constraining step of adjusting the shape of the spring material by constraining a plurality of locations of the spring material formed into a predetermined shape, and a spring material formed into a predetermined shape An electrode clamping step for clamping both ends of the electrode with a pair of electrodes, and an opening step for opening the portion restrained in the restraining step without changing the relative position between the pair of electrodes after the restraining step and the electrode clamping step; It has the 1st heating process which heats a spring material by sending an electric current through a spring material through a pair of electrodes after a process.

この製造方法では、ばね材に電流を流すことでばね材を加熱する。すなわち、通電加熱によってばね材を加熱する。通電加熱は、ばね材を短時間で加熱できるため、熱処理に要する時間を短時間化することができる。   In this manufacturing method, the spring material is heated by passing an electric current through the spring material. That is, the spring material is heated by energization heating. Since current heating can heat the spring material in a short time, the time required for the heat treatment can be shortened.

また、ばね材の一端と他端の間に曲げ部を有し、一端と他端の間においてばね材同士が接触していないばねを熱処理する場合、熱処理による寸法変化が生じ易い。すなわち、この種のばねでは、曲げ部の曲率半径に対してばね材の断面積が小さいことが多く、ばね材の外形状がばらつき易く、熱処理による変形量も大きい。また、熱処理による寸法変化は、ばね材の製造ロットによっても変化する。したがって、この種のばねを熱処理する場合、熱処理後の寸法のずれを抑制する必要がある。上記の製造方法では、熱処理前に、ばね材の複数個所を拘束してばね材の形状を調整し、その形状が保持されるように一対の電極の相対的位置を維持しながら通電加熱を行う。その結果、第1加熱工程後のばね材の形状が所望の形状からずれることが抑制される。なお、ばね材の複数個所を拘束しても、通電加熱時には拘束された部位が開放されている。このため、ばね材の加熱にばらつきが生じることを防止することができる。なお、電極でクランプされた部位は、電極でクランプされていない部位と比較して加熱されない。ただし、通電加熱が終了した後に電極から開放されると、電極でクランプされていない部位からの熱伝導によって加熱されて熱処理が行われる。   Further, when a spring having a bent portion between one end and the other end of the spring material and the spring materials are not in contact with each other between the one end and the other end, a dimensional change due to the heat treatment is likely to occur. That is, in this type of spring, the cross-sectional area of the spring material is often small with respect to the radius of curvature of the bent portion, the outer shape of the spring material tends to vary, and the amount of deformation due to heat treatment is also large. Moreover, the dimensional change by heat processing changes also with the manufacturing lot of a spring material. Therefore, when heat-treating this type of spring, it is necessary to suppress a dimensional shift after the heat treatment. In the above manufacturing method, before heat treatment, the spring material is constrained at a plurality of positions to adjust the shape of the spring material, and the heating is performed while maintaining the relative positions of the pair of electrodes so that the shape is maintained. . As a result, the shape of the spring material after the first heating step is suppressed from deviating from the desired shape. In addition, even if it restrains several places of a spring material, the site | part restrained at the time of energization heating is open | released. For this reason, it can prevent that dispersion | variation arises in the heating of a spring material. In addition, the site | part clamped with the electrode is not heated compared with the site | part which is not clamped with the electrode. However, when the electrode is released after the energization heating is completed, the heat treatment is performed by being heated by heat conduction from a portion not clamped by the electrode.

上記のばねの製造方法では、第1加熱工程後に、ばね材から電極を開放して、ばね材の電極でクランプされていた部位を追加熱する第2加熱工程をさらに有していてもよい。第2加熱工程を行うことで、電極でクランプされていた部位が追加熱され、ばね材の全体に短時間で熱処理を行うことができる。   The spring manufacturing method may further include a second heating step of opening the electrode from the spring material and additionally heating the portion clamped by the electrode of the spring material after the first heating step. By performing a 2nd heating process, the site | part clamped with the electrode is additionally heated, and the whole spring material can be heat-processed in a short time.

なお、第2加熱工程では、ばね材の電極でクランプされていた部位に加熱した部材を押し付けてもよい。加熱した部材を押し付けることで、クランプされていた部位を簡易に加熱することができる。   In the second heating step, the heated member may be pressed against the portion clamped by the spring material electrode. By pressing the heated member, the clamped part can be easily heated.

実施例に係る線細工ばねの平面図。The top view of the wirework spring which concerns on an Example. 端部の高さ方向のずれを模式的に示す図。The figure which shows typically the shift | offset | difference of the height direction of an edge part. 線細工ばねの製造工程を示すフローチャート。The flowchart which shows the manufacturing process of a wire work spring. 熱処理の手順を示す図(その1)。The figure which shows the procedure of heat processing (the 1). 熱処理の手順を示す図(その2)。The figure which shows the procedure of heat processing (the 2). 熱処理の手順を示す図(その3)。The figure which shows the procedure of heat processing (the 3). 熱処理の手順を示す図(その4)。The figure which shows the procedure of heat processing (the 4). ばね材の両端を一対の電極でクランプした状態を示す図。The figure which shows the state which clamped both ends of the spring material with a pair of electrode.

実施例1に係るばねの製造方法について説明する。まず、実施例1において製造されるばねについて説明する。実施例1では線細工ばねを製造する。図1に示すように、線細工ばね10は、1箇所を曲げ加工されたばね材(線材)により構成されている。ばね材には、鋼線(例えば、硬鋼線,ピアノ線,オイルテンパー線,ステンレス鋼線等)を用いることができる。線細工ばね10の一端14と他端16とは離れており、一端14と他端16の間において、ばね材同士は接触していない。線細工ばね10は、その中間位置において曲げ部12を有している。曲げ部12においては、ばね材の軸線は90度変化している。すなわち、図1において、一端14から下方向に伸びているばね材の軸線は、曲げ部12において、水平方向に伸びるように変化している。   A method for manufacturing the spring according to the first embodiment will be described. First, the spring manufactured in Example 1 will be described. In Example 1, a wire work spring is manufactured. As shown in FIG. 1, the wirework spring 10 is composed of a spring material (wire material) that is bent at one place. A steel wire (for example, a hard steel wire, a piano wire, an oil temper wire, a stainless steel wire, etc.) can be used as the spring material. One end 14 and the other end 16 of the wirework spring 10 are separated from each other, and the spring material is not in contact between the one end 14 and the other end 16. The wirework spring 10 has a bent portion 12 at an intermediate position thereof. In the bent portion 12, the axis of the spring material changes by 90 degrees. That is, in FIG. 1, the axis of the spring material extending downward from the one end 14 changes in the bent portion 12 so as to extend in the horizontal direction.

なお、線細工ばね10を量産すると、その形状にばらつきが生じる場合がある。例えば、図2に示すように、線細工ばね10の一端14が、他端16に対して高さ方向にずれる場合がある。かかる場合は、出荷前にばね材の形状を矯正する矯正工程を実施し、ばね材の両端14,16の高さ方向のずれが許容値内となるようにしている。また、曲げ部12の曲率半径にばらつきが生じる場合がある。この場合も、出荷前に曲げ部12の曲率半径を矯正し、曲げ部12の曲率半径が許容値内となるようにしている。あるいは、ばね材の適宜の箇所を冶具により拘束し、冶具ごと低温焼鈍しを施すことによって、ばね材の形状のばらつきを抑制することが行われる。   In addition, when the wirework spring 10 is mass-produced, the shape may vary. For example, as shown in FIG. 2, one end 14 of the wirework spring 10 may be shifted in the height direction with respect to the other end 16. In such a case, a correction process for correcting the shape of the spring material is performed before shipment so that the deviation in the height direction of both ends 14 and 16 of the spring material is within an allowable value. In addition, the curvature radius of the bent portion 12 may vary. Also in this case, the radius of curvature of the bent portion 12 is corrected before shipment so that the radius of curvature of the bent portion 12 is within an allowable value. Alternatively, a variation in the shape of the spring material is suppressed by restraining an appropriate portion of the spring material with a jig and performing low-temperature annealing together with the jig.

次に、線細工ばね10の製造方法を、図3を参照して説明する。図3に示すように、まず、線細工ばね10の材料となるばね材(例えば、ばね鋼の線材)に前処理を施す。すなわち、成形機(例えば、ガイドローラを使用するNCコイリング方式の成形機等)によってばね材を所望の形状(製品形状)に成形する。この段階では熱処理は未実施であるため、ばね材には塑性加工によって加工歪みが生じている。   Next, a method for manufacturing the wirework spring 10 will be described with reference to FIG. As shown in FIG. 3, first, pretreatment is performed on a spring material (for example, a wire rod of spring steel) that is a material of the wirework spring 10. That is, the spring material is formed into a desired shape (product shape) by a molding machine (for example, an NC coiling type molding machine using a guide roller). At this stage, no heat treatment has been performed, so that the spring material is strained by plastic working.

次に、製品形状に成形されたばね材に熱処理(いわゆる、低温焼鈍し)が行われる(S12)。上述したように、前処理における塑性加工によって、ばね材には加工歪みが生じている。このため、ステップS12では、製品形状に成形されたばね材に、加工歪みを除去するための熱処理が行われる。これによって、線細工ばね10のばね特性(例えば、耐久性、耐へたり性、耐脆性)が改善される。   Next, heat treatment (so-called low temperature annealing) is performed on the spring material formed into a product shape (S12). As described above, due to the plastic working in the pretreatment, the spring material has a working strain. For this reason, in step S12, the spring material molded into the product shape is subjected to heat treatment for removing processing distortion. Thereby, the spring characteristics (for example, durability, sag resistance, brittleness resistance) of the wirework spring 10 are improved.

ステップS12の熱処理は、ばね材を通電加熱する通電加熱工程(S12(第1加熱工程の一例に相当))と、ばね材の端部(14,16)を加熱する端部加熱工程(S14(第2加熱工程の一例))によって構成されている。ステップS12,14の熱処理について、図4a〜4dを参照して詳細に説明する。   The heat treatment of step S12 includes an energization heating process (S12 (corresponding to an example of a first heating process) for energizing and heating the spring material, and an end heating process (S14 (equivalent to an example of the first heating process) and the end portions (14, 16) of the spring material. An example of the second heating step)). The heat treatment in steps S12 and S14 will be described in detail with reference to FIGS.

図4aに示すように、製品形状に成形されたばね材は、まず、熱処理後にばね材の形状が製品形状となるように、その複数個所(本実施例では、両端14,16の近傍の2箇所と曲げ部12の1箇所の合計3箇所)をクランプ部材18によってクランプする(図4aの状態)。すなわち、前処理によってばね材を製品形状に成形すると、加工歪みが残留するため、熱処理後に製品形状が変化する。特に、曲げ部12の曲率半径に対してばね材の断面積が小さくなる場合は、曲げ部12の形状変化が大きい。このため、ばね材の複数個所をクランプすることで、各クランプ部位における寸法変化を予め強制的に付与し、熱処理後の寸法を安定させる。具体的には、ばね材の一端14の近傍をクランプ部材18a,18bによってクランプし、ばね材の曲げ部12をクランプ部材18c,18d,18eによってクランプし、ばね材の他端16の近傍をクランプ部材18f,18gでクランプする。次いで、クランプ部材18a〜18gの位置を調整することで、クランプした各部位(両端14,16の近傍及び曲げ部12)において、ばね材の形状を所望の形状に矯正する。例えば、熱処理前のばね材の曲率半径(曲げ部12の曲率半径)が熱処理後の製品形状(設計値)より大きい場合は、クランプ部材18a〜18gを曲率半径が小さくなる方向に移動させ、ばね材の曲率半径を縮小させる。あるいは、ばね材の径が熱処理後の製品形状(設計値)より小さい場合は、クランプ部材18a〜18gを曲率半径が大きくなる方向に移動させ、ばね材の曲率半径を拡大させる。これにより、ばね材の位置ずれを解消する。なお、ばね材をクランプする位置及び数は、上記の例に限られない。また、上記の例では、曲げ部12の内側にクランプ部材18c(曲げ部12の曲率に倣った外周面を有するクランプ部材)を当接させ、そのクランプ部材18cに当接する部分の両側にクランプ部材18d,18eを当接させ、曲げ部12をクランプした。しかしながら、曲げ部12をクランプする方法は、このような方法に限られず、例えば、ばね材の曲率に応じた当接面を備えた2つのクランプ部材によってクランプしてもよい。   As shown in FIG. 4a, the spring material molded into the product shape is first formed at a plurality of locations (in this embodiment, two locations near both ends 14, 16) so that the shape of the spring material becomes the product shape. And a total of three places of the bent portion 12) are clamped by the clamp member 18 (state of FIG. 4a). That is, when the spring material is formed into a product shape by pre-processing, since the processing strain remains, the product shape changes after the heat treatment. In particular, when the cross-sectional area of the spring material is small with respect to the curvature radius of the bent portion 12, the shape change of the bent portion 12 is large. For this reason, by clamping a plurality of locations of the spring material, a dimensional change at each clamp portion is forcibly applied in advance, and the dimensions after the heat treatment are stabilized. Specifically, the vicinity of one end 14 of the spring material is clamped by the clamp members 18a and 18b, the bent portion 12 of the spring material is clamped by the clamp members 18c, 18d and 18e, and the vicinity of the other end 16 of the spring material is clamped Clamp with members 18f and 18g. Next, by adjusting the positions of the clamp members 18a to 18g, the shape of the spring material is corrected to a desired shape at each clamped portion (in the vicinity of both ends 14, 16 and the bent portion 12). For example, when the curvature radius of the spring material before the heat treatment (the curvature radius of the bent portion 12) is larger than the product shape (design value) after the heat treatment, the clamp members 18a to 18g are moved in a direction in which the radius of curvature decreases, and the spring Reduce the radius of curvature of the material. Or when the diameter of a spring material is smaller than the product shape (design value) after heat processing, the clamp members 18a-18g are moved to the direction where a curvature radius becomes large, and the curvature radius of a spring material is expanded. Thereby, the position shift of a spring material is eliminated. In addition, the position and number which clamp a spring material are not restricted to said example. In the above example, the clamp member 18c (a clamp member having an outer peripheral surface that follows the curvature of the bent portion 12) is brought into contact with the inside of the bent portion 12, and the clamp members are disposed on both sides of the portion that comes into contact with the clamp member 18c. 18d and 18e were made to contact and the bending part 12 was clamped. However, the method of clamping the bent portion 12 is not limited to such a method, and for example, the bending portion 12 may be clamped by two clamping members having contact surfaces according to the curvature of the spring material.

ばね材がクランプ部材18a〜18gによってクランプされると、次に、ばね材の両端14,16の高さが同一となるように、ばね材の一端14を一対の電極20a,20bでクランプすると共に、ばね材の他端16を一対の電極22a,22bでクランプする(図4bの状態)。すなわち、ばね材を製品形状に成形すると、ばね材の両端14,16に高さ方向の位置ずれが生じ易い(図2の状態)。このため、図5に示すように、両端の電極対の一方(例えば、ばね材の一端14をクランプする電極20a,20b)を固定し、この固定した一方に対して他方の電極(例えば、ばね材の他端16をクランプする電極22a,22b)を高さ方向に移動させ、ばね材の両端14,16の高さを一致させる。これにより、前処理によって生じる、ばね材の両端14,16の高さ方向の位置ずれが矯正される。ばね材の両端14,16を電極(20a,20b),(22a,22b)でクランプした状態では、クランプ部材18a〜18gによって曲げ部12の形状が矯正され、また、電極(20a,20b),(22a,22b)によって両端14,16の高さ方向の位置が矯正されている。すなわち、ばね材が所望の製品寸法となるように矯正されている。   When the spring material is clamped by the clamp members 18a to 18g, next, the one end 14 of the spring material is clamped with the pair of electrodes 20a and 20b so that the both ends 14 and 16 of the spring material are the same. The other end 16 of the spring material is clamped with a pair of electrodes 22a and 22b (state shown in FIG. 4b). That is, when the spring material is molded into a product shape, the two ends 14 and 16 of the spring material are likely to be displaced in the height direction (state shown in FIG. 2). Therefore, as shown in FIG. 5, one of the electrode pairs at both ends (for example, the electrodes 20a and 20b for clamping the one end 14 of the spring material) is fixed, and the other electrode (for example, the spring) is fixed to the fixed one. The electrodes 22a and 22b) for clamping the other end 16 of the material are moved in the height direction so that the heights of the ends 14 and 16 of the spring material are matched. Thereby, the position shift of the height direction of both ends 14 and 16 of a spring material which arises by pre-processing is corrected. In a state where both ends 14 and 16 of the spring material are clamped by the electrodes (20a, 20b) and (22a, 22b), the shape of the bent portion 12 is corrected by the clamp members 18a to 18g, and the electrodes (20a, 20b), The positions in the height direction of both ends 14 and 16 are corrected by (22a, 22b). That is, the spring material is corrected so as to have a desired product size.

次に、ばね材からクランプ部材18a〜18gを取外して、ばね材を開放する(図4cの状態)。クランプ部材18a〜18gをばね材から取り外した状態でも、電極(20a,20b),(22a,22b)の相対的な位置関係は保持される。すなわち、電極(20a,20b),(22a,22b)の相対的な位置関係は、クランプ部材18a〜18gでクランプした状態(図4bの状態)と、クランプ部材18を取り外した状態(図4cの状態)とで変化しない。このため、ばね材の両端14,16の位置は、適切な位置で保持され、また、各曲げ部12の曲率半径も所望の径に保持されている。   Next, the clamp members 18a to 18g are removed from the spring material, and the spring material is opened (state of FIG. 4c). Even in a state where the clamp members 18a to 18g are removed from the spring material, the relative positional relationship between the electrodes (20a, 20b) and (22a, 22b) is maintained. That is, the relative positional relationship between the electrodes (20a, 20b) and (22a, 22b) is such that the clamp members 18a to 18g are clamped (the state shown in FIG. 4b) and the clamp member 18 is removed (the one shown in FIG. 4c). Status). For this reason, the positions of both ends 14 and 16 of the spring material are held at appropriate positions, and the radius of curvature of each bending portion 12 is also held at a desired diameter.

ばね材からクランプ部材18a〜18gを取外すと、電極(20a,20b),(22a,22b)間に電圧を印加し、ばね材に電流を流してばね材を加熱する(図4cの状態)。通電加熱時には、ばね材とクランプ部材18a〜18gとが接触していないため、ばね材からクランプ部材18a〜18gに電流が流れる事態(いわゆる漏電)や、クランプ部材18a〜18gによる放熱が防止される。これによって、ばね材の全体が均一に、かつ、安全に加熱される。また、通電加熱を用いることで、ばね材を短時間で所望の処理温度まで昇温することができる。この通電加熱処理により、ばね材に発生した加工歪みが除去され、ばね材に所望の機械的特性が付与される。   When the clamp members 18a to 18g are removed from the spring material, a voltage is applied between the electrodes (20a, 20b) and (22a, 22b), and an electric current is passed through the spring material to heat the spring material (state of FIG. 4c). At the time of energization heating, the spring material and the clamp members 18a to 18g are not in contact with each other, so that a situation where current flows from the spring material to the clamp members 18a to 18g (so-called electric leakage) and heat dissipation by the clamp members 18a to 18g are prevented. . Thereby, the whole spring material is uniformly and safely heated. Further, by using energization heating, the spring material can be heated to a desired processing temperature in a short time. By this energization heat treatment, processing distortion generated in the spring material is removed, and desired mechanical characteristics are imparted to the spring material.

なお、通電加熱によりばね材を短時間で加熱できるため、ばね材の処理温度(例えば、370℃)は、加熱炉を用いた場合の処理温度(例えば、335℃)より高い温度に設定される。また、ばね材の処理時間(例えば、3秒)は、加熱炉を用いた場合の処理時間(例えば、7分)より短い時間に設定される。なお、ばね材の処理温度が高すぎるとばね材に機械的特性の劣化が発生するため、処理温度は600℃以下に設定することが好ましい。   In addition, since the spring material can be heated in a short time by energization heating, the processing temperature (for example, 370 ° C.) of the spring material is set to a temperature higher than the processing temperature (for example, 335 ° C.) when the heating furnace is used. . Moreover, the processing time (for example, 3 seconds) of the spring material is set to a time shorter than the processing time (for example, 7 minutes) when the heating furnace is used. Note that if the treatment temperature of the spring material is too high, the mechanical properties of the spring material are deteriorated. Therefore, the treatment temperature is preferably set to 600 ° C. or lower.

通電加熱が終了すると、ばね材から電極(20a,20b),(22a,22b)を取外す。次いで、ばね材の両端14,16を、加熱した一対のばね材の断面形状に倣った形状を有する部材24,26(例えば、440℃)で上下方向から押圧することで、ばね材の端部14,16を熱処理する(図4dの状態)。すなわち、通電加熱時において、電極(20a,20b),(22a,22b)でクランプされていた部分(すなわち、ばね材の端部14,16)は、電流が流れ難く、また、電極(20a,20b),(22a,22b)を介して放熱されるため、温度が上昇し難い。電極(20a,20b),(22a,22b)を開放した後に一定時間放置することで、熱伝導により電極(20a,20b),(22a,22b)でクランプされていた部位も熱処理の効果が得られる。しかしながら、熱伝導による熱処理では放置する時間が長くなるために、外乱因子(例えば風)の影響により機械的特性の安定が得にくい。そこで、クランプされていた部位に短時間で熱処理の効果を付与するため、通電加熱後に、ばね材のうち電極(20a,20b),(22a,22b)でクランプされていた部分を追加熱することで、ばね材の全体を熱処理する。   When the current heating is finished, the electrodes (20a, 20b), (22a, 22b) are removed from the spring material. Next, the ends of the spring material are pressed by pressing both ends 14 and 16 of the spring material from above and below with members 24 and 26 (for example, 440 ° C.) having a shape following the cross-sectional shape of the pair of heated spring materials. 14 and 16 are heat-treated (state shown in FIG. 4d). That is, at the time of energization heating, the current clamped by the electrodes (20a, 20b), (22a, 22b) (that is, the end portions 14 and 16 of the spring material) is difficult for the current to flow, and the electrodes (20a, 20b) and (22a, 22b), so that the heat is not easily raised. By leaving the electrodes (20a, 20b), (22a, 22b) for a certain period of time, the heat-treated effect can be obtained even for the parts clamped by the electrodes (20a, 20b), (22a, 22b) by heat conduction. It is done. However, in the heat treatment by heat conduction, since the time for which it is left is long, it is difficult to obtain stable mechanical characteristics due to the influence of a disturbance factor (for example, wind). Therefore, in order to give the effect of heat treatment to the clamped portion in a short time, after the energization heating, the portion clamped by the electrodes (20a, 20b), (22a, 22b) of the spring material is additionally heated. Then, the entire spring material is heat-treated.

ばね材の両端部14,16の加熱が終了すると、ばね材に後処理(例えば、防錆処理等)を実施する(図3の後処理)。これによって、線細工ばね10が製造される。   When the heating of both ends 14 and 16 of the spring material is completed, the spring material is subjected to post-treatment (for example, rust prevention treatment) (post-treatment in FIG. 3). Thereby, the wirework spring 10 is manufactured.

上述したことから明らかなように、本実施例の製造方法では、ばね材を通電加熱によって加熱することで、熱処理時間を大幅に短縮することができる。その結果、前処理に要する時間と、通電加熱工程(S12)に要する時間と、端部加熱工程(S14)に要する時間と、後処理に要する時間とを略同一とすることができ、各工程に1個ずつばねを流すことができる。   As is apparent from the above description, in the manufacturing method of the present embodiment, the heat treatment time can be significantly shortened by heating the spring material by energization heating. As a result, the time required for the pretreatment, the time required for the energization heating step (S12), the time required for the end portion heating step (S14), and the time required for the post-treatment can be made substantially the same. One spring can be flown at a time.

また、本実施例では、通電加熱処理前に、ばね材の複数個所をクランプ部材18a〜18g及び電極(20a,20b),(22a,22b)で拘束してばね材の形状を調整し、その形状が調整された状態のまま通電加熱処理が行われる。その結果、熱処理後のばね材の形状精度が向上し、矯正作業を行う頻度や寸法不良の発生を大幅に低減することができる。なお、ばね材をクランプ部材18a〜18gでクランプしても、通電加熱時には、クランプ部材18a〜18gはばね材を開放している。このため、ばね材の加熱にばらつきが生じることや、クランプ部材18a〜18gによる漏電が生じることを防止することができる。   Further, in this embodiment, before the current heating process, the spring material is constrained by the clamp members 18a to 18g and the electrodes (20a, 20b) and (22a, 22b) to adjust the shape of the spring material, The energization heating process is performed with the shape adjusted. As a result, the shape accuracy of the spring material after heat treatment is improved, and the frequency of correction work and the occurrence of dimensional defects can be greatly reduced. Even when the spring material is clamped by the clamp members 18a to 18g, the clamp members 18a to 18g open the spring material during energization heating. For this reason, it is possible to prevent variation in heating of the spring material and occurrence of electric leakage due to the clamp members 18a to 18g.

さらに、本実施例では、通電加熱後に、ばね材のうち電極(20a,20b),(22a,22b)でクランプしていた部位を、加熱された部材24,26で追加熱する。このため、ばね材の両端部14,16を含めた全体が加熱され、ばね材の全体に所望の機械的特性を付与することができる。   Further, in the present embodiment, after energization heating, the portion clamped by the electrodes (20a, 20b), (22a, 22b) in the spring material is additionally heated by the heated members 24, 26. For this reason, the whole including the both ends 14 and 16 of a spring material is heated, and a desired mechanical characteristic can be provided to the whole spring material.

以上、本明細書に開示の技術の具体例を詳細に説明したが、これらは例示にすぎず、特許請求の範囲を限定するものではない。特許請求の範囲に記載の技術には、以上に例示した具体例を様々に変形、変更したものが含まれる。   As mentioned above, although the specific example of the technique disclosed by this specification was demonstrated in detail, these are only illustrations and do not limit a claim. The technology described in the claims includes various modifications and changes of the specific examples illustrated above.

例えば、上述した実施例において、ばね材の通電加熱処理は、ばね材の表面温度を測定し、その測定した表面温度に基づいて行ってもよい。このように構成することで、ばね材の温度を所望の温度に精度良く加熱することができる。なお、ばね材の表面温度の測定には、熱電対や放射温度計等を用いることができる。さらに、ばね材の両端部14,16の温度を測定し、その測定した温度に基づいて端部加熱工程(S14)における加熱部材24,26の温度や加熱時間等を調整するようにしてもよい。   For example, in the above-described embodiments, the energization heating treatment of the spring material may be performed based on the measured surface temperature by measuring the surface temperature of the spring material. By comprising in this way, the temperature of a spring material can be accurately heated to desired temperature. In addition, a thermocouple, a radiation thermometer, etc. can be used for the measurement of the surface temperature of a spring material. Furthermore, the temperature of both ends 14 and 16 of the spring material may be measured, and the temperature and heating time of the heating members 24 and 26 in the end heating step (S14) may be adjusted based on the measured temperature. .

また、上述した実施例においては、ばね材をクランプ部材18a〜18gでクランプした後に、ばね材の両端部14,16を電極(20a,20b),(22a,22b)でクランプしたが、本明細書に開示の技術は、このような例に限られない。例えば、ばね材の両端14,16を電極でクランプした後、ばね材をクランプ部材でクランプして形状を矯正してもよい。この場合は、ばね材の形状をクランプ部材でクランプして矯正する間は、ばね材の両端14,16をクランプしている電極を自由に移動させ、ばね材の形状を矯正後は電極間の相対位置が変化しないように電極の位置を保持すればよい。あるいは、クランプ部材によるばね材のクランプと、電極によるばね材の両端部14,16のクランプとを、同時に行うようにしてもよい。   In the above-described embodiment, the spring material is clamped by the clamp members 18a to 18g, and then both ends 14 and 16 of the spring material are clamped by the electrodes (20a, 20b) and (22a, 22b). The technology disclosed in the book is not limited to such an example. For example, after clamping the both ends 14 and 16 of a spring material with an electrode, you may clamp a spring material with a clamp member, and may correct a shape. In this case, while the shape of the spring material is clamped and corrected by the clamp member, the electrodes clamping both ends 14 and 16 of the spring material are freely moved, and after correcting the shape of the spring material, between the electrodes What is necessary is just to hold | maintain the position of an electrode so that a relative position may not change. Or you may make it perform simultaneously the clamp of the spring material by a clamp member, and the clamp of the both ends 14 and 16 of the spring material by an electrode.

なお、上述した各実施例では、L字型の線細工ばねを製造する例であったが、本明細書に開示の技術は、その他の形状の線細工ばね(例えば、S字型の線細工ばね、ジグザグ状の線細工ばね等)や、線細工ばね以外のばね(例えば、ホースクランプ、渦巻きばね、ねじりコイルばね、リング状のばね(例えば、スナップリング)等)を製造する場合にも適用することができる。   In each of the above-described embodiments, an L-shaped wirework spring is manufactured. However, the technique disclosed in this specification is applicable to other shapes of wirework springs (for example, S-shaped wirework springs). Applicable when manufacturing springs, zigzag wire-work springs, etc., and springs other than wire-work springs (eg hose clamps, spiral springs, torsion coil springs, ring-like springs (eg snap rings), etc.) can do.

また、上述した実施例では、ばね材の端部を加熱した一対の部材を上下方向から押圧することで加熱したが、このような方法に限られない。例えば、ばね材の端部を加熱する処理には、誘導加熱、塩浴浸漬、バーナーによる加熱、熱風吹付け、赤外線照射、プラズマ加熱、レーザーによる加熱、流動層炉による加熱、過熱水蒸気を用いた加熱、磁気による加熱等を用いることができる。   Moreover, in the Example mentioned above, although heated by pressing a pair of member which heated the edge part of the spring material from an up-down direction, it is not restricted to such a method. For example, in the process of heating the end of the spring material, induction heating, salt bath immersion, heating with a burner, hot air blowing, infrared irradiation, plasma heating, laser heating, fluidized bed furnace heating, superheated steam was used. Heating, heating by magnetism, or the like can be used.

本明細書または図面に説明した技術要素は、単独であるいは各種の組み合わせによって技術的有用性を発揮するものであり、出願時請求項記載の組み合わせに限定されるものではない。また、本明細書または図面に例示した技術は複数目的を同時に達成するものであり、そのうちの一つの目的を達成すること自体で技術的有用性を持つものである。   The technical elements described in this specification or the drawings exhibit technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the technology illustrated in the present specification or the drawings achieves a plurality of objects at the same time, and has technical utility by achieving one of the objects.

10 線細工ばね
12 曲げ部
14,16 端部
18 クランプ部材
20a,20b,22a,22b 電極
24,26 加熱部材
DESCRIPTION OF SYMBOLS 10 Wire work spring 12 Bending part 14, 16 End part 18 Clamp member 20a, 20b, 22a, 22b Electrode 24, 26 Heating member

Claims (3)

ばね材の一端と他端とが離れており、一端と他端の間の少なくとも一箇所において曲げ部を有すると共に、一端と他端の間においてばね材同士が接触していないばねを製造する方法であって、
ばね材を所定形状に成形する成形工程と、
所定形状に成形されたばね材の複数個所を拘束して、ばね材の形状を調整する拘束工程と、
所定形状に成形されたばね材の両端を一対の電極でクランプする電極クランプ工程と、
拘束工程及び電極クランプ工程後に、一対の電極間の相対的位置を変えることなく、拘束工程で拘束された部位を開放する開放工程と、
開放工程後に、一対の電極を介してばね材に電流を流すことでばね材を加熱する第1加熱工程と、
を有している、ばねの製造方法。
A method of manufacturing a spring in which one end and the other end of a spring material are separated from each other, and a bent portion is provided at least at one position between the one end and the other end, and the spring material is not in contact between the one end and the other end Because
A molding step of molding the spring material into a predetermined shape;
A restraint step of restraining a plurality of locations of the spring material formed into a predetermined shape and adjusting the shape of the spring material,
An electrode clamping step of clamping both ends of a spring material formed into a predetermined shape with a pair of electrodes;
After the restraining step and the electrode clamping step, without changing the relative position between the pair of electrodes, an opening step for opening the part restrained in the restraining step;
A first heating step of heating the spring material by passing a current through the spring material through the pair of electrodes after the opening step;
A method for manufacturing a spring.
第1加熱工程後に、ばね材から電極を開放して、ばね材の電極でクランプされていた部位を追加熱する第2加熱工程をさらに有している、請求項1に記載のばねの製造方法。   2. The method for manufacturing a spring according to claim 1, further comprising a second heating step of opening the electrode from the spring material after the first heating step and additionally heating the portion clamped by the electrode of the spring material. . 第2加熱工程では、ばね材の電極でクランプされていた部位に加熱した部材を押し付ける、請求項2に記載のばねの製造方法。   The manufacturing method of the spring of Claim 2 which presses the heated member to the site | part clamped with the electrode of the spring material at a 2nd heating process.
JP2013045477A 2013-03-07 2013-03-07 Spring production method Pending JP2014173115A (en)

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2017025361A (en) * 2015-07-17 2017-02-02 トヨタ自動車株式会社 Electric conduction heating device (method)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2017025361A (en) * 2015-07-17 2017-02-02 トヨタ自動車株式会社 Electric conduction heating device (method)

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