JPH0578746A - Manufacture of bushing for crawler - Google Patents
Manufacture of bushing for crawlerInfo
- Publication number
- JPH0578746A JPH0578746A JP3271800A JP27180091A JPH0578746A JP H0578746 A JPH0578746 A JP H0578746A JP 3271800 A JP3271800 A JP 3271800A JP 27180091 A JP27180091 A JP 27180091A JP H0578746 A JPH0578746 A JP H0578746A
- Authority
- JP
- Japan
- Prior art keywords
- bushing
- outer peripheral
- peripheral side
- preform
- crawler
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 12
- 230000002093 peripheral effect Effects 0.000 claims abstract description 46
- 229910052799 carbon Inorganic materials 0.000 claims abstract description 30
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims abstract description 29
- 230000006698 induction Effects 0.000 claims abstract description 21
- 229910000851 Alloy steel Inorganic materials 0.000 claims abstract description 12
- 238000005496 tempering Methods 0.000 claims abstract description 12
- 238000001816 cooling Methods 0.000 claims abstract description 7
- FBPFZTCFMRRESA-JGWLITMVSA-N D-glucitol Chemical group OC[C@H](O)[C@@H](O)[C@H](O)[C@H](O)CO FBPFZTCFMRRESA-JGWLITMVSA-N 0.000 claims abstract description 6
- 239000000463 material Substances 0.000 claims description 49
- 238000005255 carburizing Methods 0.000 claims description 18
- 238000000034 method Methods 0.000 abstract description 53
- 238000010438 heat treatment Methods 0.000 abstract description 15
- 238000010791 quenching Methods 0.000 abstract description 10
- 230000000171 quenching effect Effects 0.000 abstract description 9
- 229910000734 martensite Inorganic materials 0.000 abstract description 3
- 238000007670 refining Methods 0.000 abstract description 3
- 229910000831 Steel Inorganic materials 0.000 description 6
- 238000007796 conventional method Methods 0.000 description 6
- 239000010959 steel Substances 0.000 description 6
- 229910000677 High-carbon steel Inorganic materials 0.000 description 3
- 238000005299 abrasion Methods 0.000 description 3
- 239000007788 liquid Substances 0.000 description 3
- 229910001209 Low-carbon steel Inorganic materials 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- 229910000954 Medium-carbon steel Inorganic materials 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 230000002542 deteriorative effect Effects 0.000 description 1
- 239000000428 dust Substances 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 239000002436 steel type Substances 0.000 description 1
- 238000010998 test method Methods 0.000 description 1
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P10/00—Technologies related to metal processing
- Y02P10/25—Process efficiency
Landscapes
- Heat Treatment Of Articles (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、装軌車両（例えばブル
ドーザ）などに用いる履帯用ブッシングの製造方法に関
するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a track bushing used in a tracked vehicle (eg, bulldozer).
【０００２】[0002]
【従来の技術】装軌車両などに用いる履帯１は、図１に
示すように、シュー２、シュー締付けボルト３、シュー
締付けナット４、リンク５および６、ブッシング７、ダ
ストシール８、ピン９をもってその一単位が構成されて
いる。BACKGROUND ART A crawler belt 1 used for a tracked vehicle or the like has a shoe 2, a shoe tightening bolt 3, a shoe tightening nut 4, links 5 and 6, a bushing 7, a dust seal 8 and a pin 9, as shown in FIG. One unit is made up.
【０００３】履帯１に用いられるブッシング７は、図２
に示すように、その内周表面７ａおよび外周表面７ｂに
耐摩耗性が要求されるとともに、ブッシング７に加わる
負荷に耐えるため、強度、靱性が要求される。The bushing 7 used for the crawler belt 1 is shown in FIG.
As shown in FIG. 2, the inner peripheral surface 7a and the outer peripheral surface 7b are required to have wear resistance, and in order to withstand the load applied to the bushing 7, strength and toughness are required.
【０００４】このような要求を満足するため、従来、次
に示す（イ）、（ロ）、（ハ）の履帯用ブッシングの製
造方法が提案されている。In order to satisfy such requirements, conventionally, the following methods (a), (b) and (c) for manufacturing a track bushing have been proposed.
【０００５】（イ） 特公昭５２−３４８０６号公報に
示すように、材料に低炭素鋼である肌焼鋼（例えばＪＩ
Ｓ：ＳＣＭ４１５）を用い、素材の表面に浸炭を施し、
その後焼入れし、焼もどしする方法。浸炭によって表面
に耐摩耗性が得られ、肌焼鋼の焼入れ、焼もどしによっ
て芯部に強度、靱性が得られる。(A) As shown in Japanese Patent Publication No. 52-34806, case hardening steel (for example, JI) which is low carbon steel is used as a material.
S: SCM415), carburize the surface of the material,
Then quench and temper. Abrasion resistance is obtained on the surface by carburization, and strength and toughness are obtained on the core by quenching and tempering case hardening steel.
【０００６】（ロ） 特願昭６３−８７３３８号で提案
したように、かつ図３に示すように、中程度に炭素を含
む鋼から成るブッシング素材に浸炭を施した後常温迄冷
却する工程と、その後、ブッシング素材を、軸線１０ａ
を中心にして回転させつつ、その外周表面１０ｂから、
外周側浸炭層を越えて高周波焼入れを施し、有効硬さ以
上の硬さにして外周有効硬化層を形成する工程と、ブッ
シング素材を軸線を中心にして回転させ、かつ、前記外
周表面を液冷しつつ、その内周表面１０ｃから内周側浸
炭層を越えて高周波焼入れを施し、該ブッシング素材
に、内周有効硬化層を形成すると同時に、内、外有効硬
化層の間に、前記有効硬さ以下の硬さを有する焼もどし
層を形成する工程と、その後、前記ブッシングを低温で
焼もどしする工程と、を有することを特徴とする、中程
度の炭素を含む履帯用ブッシングの製造方法。(B) As proposed in Japanese Patent Application No. 63-87338 and as shown in FIG. 3, a step of carburizing a bushing material made of steel containing medium carbon and then cooling to room temperature. , Then the bushing material, the axis 10a
While rotating about, from the outer peripheral surface 10b,
Induction hardening beyond the outer peripheral side carburized layer to form an outer peripheral effective hardened layer with a hardness not less than the effective hardness, and rotating the bushing material around the axis and liquid cooling the outer peripheral surface. At the same time, induction hardening is performed from the inner peripheral surface 10c beyond the inner peripheral side carburized layer to form an inner peripheral effective hardened layer on the bushing material, and at the same time, the effective hardened layer is formed between the inner and outer effective hardened layers. A method for manufacturing a bushing for a crawler track containing medium carbon, comprising the steps of forming a tempering layer having a hardness equal to or less than that, and then tempering the bushing at a low temperature.
【０００７】（ハ） 特願昭６３−３２０４２０号で提
案したように、中程度の炭素量を含む鋼を素材とする履
帯用ブッシング素材に、浸炭を施して常温迄冷却し、そ
の後、履帯用ブッシング素材に、外周表面のみから肉厚
全体を加熱するように高周波誘導加熱し、冷却して焼入
れを施し、その後、焼もどしする方法。これら（イ）、
（ロ）、（ハ）の方法のうち、実用化されているのは、
（イ）の方法である。(C) As proposed in Japanese Patent Application No. 63-320420, a track bushing material made of steel containing a medium amount of carbon is carburized and cooled to room temperature, and then used for tracks. A method in which the bushing material is subjected to high-frequency induction heating so as to heat the entire wall thickness only from the outer peripheral surface, cooling and quenching, and then tempering. These (a),
Of the methods (b) and (c), the one that has been put to practical use is
Method (a) is used.
【０００８】[0008]
【発明が解決しようとする課題】しかし、前記（イ）の
方法には、肌焼鋼の浸炭焼入れ時間が非常に長いので、
コストがかかるという問題がある。また、前記（ロ）、
（ハ）の方法には、（イ）の方法に比べて浸炭焼入れ時
間は短いが、浸炭を施すので、熱処理時間が長くなり、
それだけ熱処理コストが高くつくという問題がある。However, in the above method (a), the carburizing and quenching time of case hardening steel is very long,
There is a problem of cost. In addition, (b),
The method (c) has a shorter carburizing and quenching time than the method (a), but since carburizing is performed, the heat treatment time becomes longer,
There is a problem that the heat treatment cost is high.
【０００９】本発明は、従来の（イ）、（ロ）、（ハ）
の方法に比べて、浸炭を省略できる履帯用ブッシングの
製造方法を提供することを目的とする。ただし、この浸
炭省略によって、履帯用ブッシングの耐摩耗性、強度、
靱性が従来より低下しないことが前提となる。The present invention relates to the conventional (a), (b) and (c)
It is an object of the present invention to provide a method for manufacturing a bushing for a crawler belt that can omit carburization as compared with the above method. However, by omitting this carburization, the wear resistance, strength, and
It is premised that the toughness does not deteriorate as compared with the conventional one.
【００１０】[0010]
【課題を解決するための手段】上記目的は、本発明に係
る次の方法によって達成される。すなわち、高炭素低合
金鋼を素材とする履帯用ブッシング素材に、浸炭を施す
ことなく、素材に調質を施して該ブッシング素材の肉厚
全体をソルバイト組織にする第１の工程と、該ブッシン
グ素材をその軸線を中心にして回転させつつ、その外周
側に高周波焼入れを施し、該ブッシング素材に外周有効
硬化層を形成する第２の工程と、ブッシング素材をその
軸線を中心にして回転させ、かつ、前記外周側を液冷し
つつ、その内周側に高周波焼入れを施し、該ブッシング
素材に内周有効硬化層を形成する第３の工程と、前記工
程の終了後、前記ブッシング素材を低温焼もどしする第
４の工程と、から成る履帯用ブッシングの製造方法。The above object can be achieved by the following method according to the present invention. That is, a bushing material for a crawler track made of high carbon low alloy steel is subjected to a tempering without carburizing to make the entire material thickness of the bushing material a sorbite structure, and the bushing. While rotating the material about its axis, a second step of subjecting the outer peripheral side to induction hardening to form an outer peripheral effective hardened layer on the bushing material, and rotating the bushing material about its axis, And, while the liquid cooling of the outer peripheral side, induction hardening is applied to the inner peripheral side to form an inner peripheral effective hardened layer on the bushing material, and the bushing material is cooled to a low temperature after the completion of the step. A method for manufacturing a track bushing, comprising a fourth step of tempering.
【００１１】[0011]
【作用】上記履帯用ブッシングの製造方法では、高炭素
量（Ｃ：０．５〜１．０％）を含む鋼材を使用している
から、浸炭は不要である。すなわち、従来の低炭素鋼お
よび中炭素鋼を素材とする場合は、炭素量が０．１〜
０．４％の素材の表面の炭素量を約０．８％にするため
に浸炭を施していたが、本発明では、素材の炭素量を、
表面に要求される炭素量と同じにした、すなわち、高炭
素鋼を用いたので、浸炭が不要となり、（イ）、
（ロ）、（ハ）の従来方法に比べて、熱処理コストが削
減される。In the above-mentioned method for manufacturing the track bushing, since the steel material containing a high carbon content (C: 0.5 to 1.0%) is used, carburization is unnecessary. That is, when conventional low-carbon steel and medium-carbon steel are used as raw materials, the carbon content is 0.1-0.1%.
Carburizing was performed to make the carbon content on the surface of 0.4% of the material about 0.8%, but in the present invention, the carbon content of the material is
The amount of carbon required for the surface was made the same, that is, because high carbon steel was used, carburization became unnecessary, and (a)
The heat treatment cost is reduced as compared with the conventional methods of (b) and (c).
【００１２】[0012]
【実施例】以下に、本発明の望ましい実施例に係る履帯
用ブッシングの製造方法を図１−図１０を参照して説明
する。本発明における履帯用ブッシング素材は、図３に
示すように、長さＬ＝１５８ｍｍ、外径Ｄ1 ＝Φ６６．
７ｍｍ、内径Ｄ2 ＝Φ４４．８ｍｍ、θ＝８０°、Ｒ＝
２ｍｍ、Ｋ＝２Ｃのものを使用した。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A method of manufacturing a track bushing according to a preferred embodiment of the present invention will be described below with reference to FIGS. As shown in FIG. 3, the crawler belt bushing material in the present invention has a length L = 158 mm, an outer diameter D 1 = Φ66.
7 mm, inner diameter D 2 = Φ44.8 mm, θ = 80 °, R =
2 mm and K = 2C were used.
【００１３】本発明におけるブッシング素材の材料は、
重量％で０．５〜１．０％のＣを含む高炭素鋼をベース
に、Ｍｎ、Ｃｒ、Ｍｏのうちの少なくとも一元素および
Ｂを添加した高炭素低合金鋼である。これらの合金元素
の添加目的および添加量は下記のとおりである。The material of the bushing material in the present invention is
It is a high carbon low alloy steel in which at least one element of Mn, Cr and Mo and B are added to a high carbon steel containing 0.5 to 1.0% by weight of C as a base. The purpose and amount of addition of these alloy elements are as follows.
【００１４】（１）Ｍｎ 目的は焼入れ性の確保であり、添加量は１．０〜２．０
％とする。 （２）Ｃｒ 目的は焼入れ性および耐摩耗性の確保であり、添加量は
０．１〜１．２％とする。 （３）Ｍｏ 目的は焼入れ性および耐摩耗性の確保であり、添加量は
材料コストを考慮して上限を０．３５％とする。 （４）Ｂ 目的は靱性の確保であり、添加量は０．０００５〜０．
００３０％とする。(1) Mn The purpose is to secure hardenability, and the addition amount is 1.0 to 2.0.
%. (2) Cr The purpose is to ensure hardenability and wear resistance, and the addition amount is 0.1 to 1.2%. (3) Mo The purpose is to secure hardenability and wear resistance, and the upper limit of the addition amount is 0.35% in consideration of material cost. (4) B The purpose is to secure toughness, and the addition amount is 0.0005 to 0.
0030%.
【００１５】表１に本発明の実施例の履帯用ブッシング
の化学成分を示す。なお、従来の（イ）の方法では、Ｊ
ＩＳ：ＳＣＭ４１５の低炭素低合金鋼が用いられ、従来
の（ロ）、（ハ）の方法では、日本自動車工業会規格：
ＡＳＣＢ４０Ｈの中炭素低合金鋼が用いられたので、参
考のためにそれらの化学成分もあわせて表１に示してあ
る。Table 1 shows the chemical composition of the track bushing of the embodiment of the present invention. In the conventional method (a), J
IS: SCM415 low-carbon low-alloy steel is used. In the conventional methods (b) and (c), the Japan Automobile Manufacturers Association Standard:
As the medium carbon low alloy steel of ASCB40H was used, their chemical compositions are also shown in Table 1 for reference.
【００１６】[0016]
【表１】 [Table 1]
【００１７】そしてこれらの鋼種から成る試験材の熱処
理方法を表２に示す。表２には従来の（イ）、（ロ）、
（ハ）の熱処理方法もあわせて示してある。Table 2 shows the heat treatment method for the test materials made of these steel types. Table 2 shows the conventional (a), (b),
The heat treatment method of (c) is also shown.
【００１８】[0018]
【表２】 [Table 2]
【００１９】表２の高周波焼入れの仕様を表３に示す。
表３には従来の（ロ）、（ハ）の高周波焼入れもあわせ
て示してある。Table 3 shows the specifications of induction hardening in Table 2.
Table 3 also shows the conventional induction hardening of (b) and (c).
【００２０】[0020]
【表３】 [Table 3]
【００２１】本発明の熱処理においては、表２にも示す
ように、第１の工程で、高炭素低合金鋼を素材とする履
帯用ブッシング素材に、浸炭を施すことなく、素材に調
質を施して、ブッシング素材の肉厚全体をソルバイト組
織にする。具体的には、８００°Ｃ〜８５０°Ｃにて加
熱して油焼入れしたのち、６００°Ｃ〜６５０°Ｃにて
加熱して焼もどしを施し、ＨＲＣ３０程度の硬さとす
る。In the heat treatment of the present invention, as shown in Table 2, in the first step, the material of the track bushing made of high carbon low alloy steel is tempered without carburizing. Apply to make the entire thickness of the bushing material a sorbite structure. Specifically, after heating at 800 ° C. to 850 ° C. for oil quenching, it is heated at 600 ° C. to 650 ° C. for tempering to obtain a hardness of about HRC30.
【００２２】続いて、第２の工程で、ブッシング素材
に、外周表面から高周波焼入れを施す。浸炭を施す必要
がないのは、ブッシング素材に高炭素鋼を使用したため
である。外周表面からの高周波焼入れではブッシング素
材をその軸線を中心にして回転させつつ、製品をコイル
に対して移動させ、その外周側に高周波焼入れを施して
ブッシング素材に外周有効硬化層を形成する。ブッシン
グ粗材を回転させる理由は外周表面全面にわたって均一
な高周波焼入れを施すためである。そして、この高周波
焼入れに当っては、高周波誘導加熱の影響がブッシング
素材の肉厚芯部および内周側に及ばないようにすること
が必要である。Subsequently, in a second step, the bushing material is induction hardened from the outer peripheral surface. The reason why carburizing is not necessary is that the bushing material is made of high carbon steel. In induction hardening from the outer peripheral surface, while rotating the bushing material about its axis, the product is moved with respect to the coil, and induction hardening is performed on the outer peripheral side of the bushing material to form an outer peripheral effective hardened layer on the bushing material. The reason for rotating the bushing rough material is to perform uniform induction hardening over the entire outer peripheral surface. In this induction hardening, it is necessary to prevent the influence of the induction heating from reaching the thick core portion and the inner peripheral side of the bushing material.
【００２３】第３の工程で外周側を液冷する理由は、内
周側の高周波焼入れで外周側が焼もどしを起こさないよ
うにするためである。そして、この高周波焼入れによっ
て、外周有効硬化層および内周有効硬化層を有し、これ
らの両有効硬化層の間にソルバイト組織から成る靱性に
富んだ層を有するブッシング素材が得られる。The reason for liquid cooling the outer peripheral side in the third step is to prevent tempering on the outer peripheral side due to induction hardening on the inner peripheral side. By this induction hardening, a bushing material having an outer peripheral effective hardened layer and an inner peripheral effective hardened layer, and having a tough layer having a sorbite structure between these effective hardened layers can be obtained.
【００２４】第４の工程では上記ブッシング素材に低温
焼もどしを施し、内外周表面付近の組織を焼入れマルテ
ンサイトから焼もどしマルテンサイトとする。これによ
って、履帯用ブッシングは完成するが、ブッシング素材
の高周波誘導加熱に当っては表面の結晶粒度が粗大化し
ないように、肉厚、内径の大きさ等を考慮して、高周波
電源および焼入れ条件を決定しなければならない。In the fourth step, the bushing material is subjected to low temperature tempering, and the structure near the inner and outer peripheral surfaces is transformed from tempered martensite to tempered martensite. Although the track bushing is completed by this, the high frequency power supply and quenching conditions are taken into consideration in consideration of the wall thickness and inner diameter so that the crystal grain size of the surface does not become coarse during high frequency induction heating of the bushing material. Have to decide.
【００２５】上記の説明から明らかなように、本発明の
履帯用ブッシングの製造方法は、長時間を要する浸炭工
程を省略したから、調質工程が入っても、生産時間が短
縮化され、経済的に大きな利益を生じ、さらに、結果物
たる履帯用ブッシングも、以下に示すように、従来の
（イ）、（ロ）、（ハ）の方法で生産された履帯用ブッ
シングと同等かそれ以上の耐摩耗性、強度および靱性を
有する。As is clear from the above description, in the method for manufacturing a track bushing of the present invention, the carburizing step, which requires a long time, is omitted. Therefore, even if the refining step is included, the production time is shortened and the economy is improved. In addition, as a result, the resulting track bushing is equal to or more than the track bushing produced by the conventional methods (a), (b) and (c), as shown below. It has abrasion resistance, strength and toughness.
【００２６】上記熱処理仕様に基づいて熱処理されたブ
ッシング素材の浸炭深さと断面硬さを以下に示す。図４
は、表２の（イ）、（ロ）、（ハ）の浸炭方法により浸
炭された浸炭層の炭素量をＸ線マイクロアナライザーに
より測定した結果、および、本発明の高炭素低合金鋼の
炭素量を示す。炭素量が０．４％以上となる領域の、表
面からの距離を浸炭深さと仮定すれば、（イ）の方法の
浸炭深さは２．２ｍｍ、（ロ）および（ハ）の方法の浸
炭深さは、ともに２．４ｍｍである。これに対して、本
発明の方法では、全肉厚が炭素量：０．５％以上であ
り、全肉厚が浸炭層になっていると考えることができ
る。The carburizing depth and cross-sectional hardness of the bushing material heat-treated based on the above heat-treatment specifications are shown below. Figure 4
Is the result of measuring the carbon content of the carburized layer carburized by the carburizing methods of (a), (b) and (c) in Table 2 by an X-ray microanalyzer, and the carbon of the high carbon low alloy steel of the present invention. Indicates the amount. Assuming that the distance from the surface in the region where the carbon content is 0.4% or more is the carburizing depth, the carburizing depth of the method (a) is 2.2 mm, and the carburizing depth of the methods (b) and (c). Both depths are 2.4 mm. On the other hand, in the method of the present invention, the total thickness is carbon amount: 0.5% or more, and it can be considered that the total thickness is the carburized layer.
【００２７】図５は（イ）の方法によるＳＣＭ４１５の
断面硬さ、図６は（ロ）の方法によるＡＳＣＢ４０Ｈの
断面硬さ、図７は（ハ）の方法によるＡＳＣＢ４０Ｈの
断面硬さ、図８は本発明方法による高炭素低合金鋼の断
面硬さである。ＪＩＳによる浸炭有効硬化層深さを規定
する硬さＨＲＣ５２．３（ＨＶ５５０）で、（イ）の方
法は２．３〜２．４ｍｍの深さになっており、前記の炭
素量０．４％の浸炭層の深さ２．２ｍｍにほぼ等しい。FIG. 5 is a sectional hardness of SCM415 by the method (a), FIG. 6 is a sectional hardness of ASCB40H by the method (b), FIG. 7 is a sectional hardness of ASCB40H by the method (c), and FIG. Is the cross-sectional hardness of the high carbon low alloy steel according to the method of the present invention. The hardness is HRC52.3 (HV550) that defines the carburizing effective hardening layer depth according to JIS, and the method (a) has a depth of 2.3 to 2.4 mm, and the carbon content is 0.4%. The depth of the carburized layer is approximately equal to 2.2 mm.
【００２８】（ロ）の方法は同様に、ＨＲＣ５２．３迄
の硬さの層の深さは内周側で２．２ｍｍ、外周側で２．
８ｍｍとなっており、外周側ではこの炭素量０．４％の
深さ２．４ｍｍに対し深くなる。（ロ）の処理方法の特
徴は、加熱の影響が、浸炭層を越えて、浸炭層に隣接す
る素材に及ぶため、浸炭有効硬さを得るのに充分な炭素
量が素材にあれば、素材の部分も硬化し、浸炭層以上の
深さの硬化層が得られることである。図６でもその傾向
が表われている。（ハ）の方法は（ロ）の方法とほぼ同
一の浸炭量であるが、図７に示すように、全肉厚がＨＲ
Ｃ５２．３以上の硬さに硬化している。Similarly, in the method (b), the depth of the layer having a hardness up to HRC 52.3 is 2.2 mm on the inner peripheral side and 2.
The depth is 8 mm, which is deeper on the outer peripheral side than the depth of 2.4 mm when the carbon content is 0.4%. The characteristic of the treatment method of (b) is that the effect of heating extends beyond the carburized layer to the material adjacent to the carburized layer, so if the material has sufficient carbon content to obtain the carburizing effective hardness, The part of is hardened and a hardened layer having a depth equal to or greater than the carburized layer is obtained. This tendency is also shown in FIG. Although the method (c) has almost the same carburizing amount as the method (b), as shown in FIG. 7, the total wall thickness is HR.
Hardened to a hardness of C52.3 or higher.
【００２９】本発明方法によるものは、図８に示すよう
に、ＨＲＣ５２．３までの硬さの層の深さは内周側で
３．２ｍｍ、外周側で３．１ｍｍとなっており、内周
側、外周側ともに、（イ）および（ロ）の方法によるも
のよりも深くなっている。これにより、（イ）および
（ロ）の方法によるものに比べて耐摩耗性および強度の
向上を期待することができる。また、（ハ）の方法によ
るものと比較すると、外周表面の硬さがＨＲＣ６０程度
である点では（ハ）の方法によるものと同じであるが、
（ハ）の方法によるものは肉厚中心部に移るにしたがっ
て硬さが低下するのに対して、本発明の方法によるもの
は、外周表面から約３ｍｍの位置までＨＲＣ５８〜６０
の硬さになっている。これにより、（ハ）の方法による
ものに比べて耐摩耗性の向上を期待することができる。
また、本発明方法によるものは、肉厚芯部に有効硬さ以
下の硬さを有する部分があるため、従来の（イ）および
（ロ）の方法によるものと同等かそれ以上の靱性を有す
ることが期待される。According to the method of the present invention, as shown in FIG. 8, the depth of the layer having a hardness up to HRC 52.3 is 3.2 mm on the inner peripheral side and 3.1 mm on the outer peripheral side. Both the peripheral side and the outer peripheral side are deeper than those obtained by the methods (a) and (b). As a result, improvement in wear resistance and strength can be expected compared to those obtained by the methods (a) and (b). Further, as compared with the method (c), the hardness of the outer peripheral surface is about HRC60, which is the same as the method (c),
In the case of the method of (c), the hardness decreases as it moves to the central part of the wall thickness, whereas in the method of the present invention, the hardness of HRC 58 to 60 increases from the outer peripheral surface to a position of about 3 mm.
It has the hardness of. Thereby, improvement in wear resistance can be expected as compared with the method (C).
In addition, the method according to the present invention has a toughness equal to or higher than those according to the conventional methods (a) and (b) because the thick core portion has a portion having a hardness less than the effective hardness. It is expected.
【００３０】図９、図１０は圧壊試験の方法を示してい
る。圧壊試験は、ブッシングから長さ：Ｌ＝３０ｍｍに
切断した試験片１２を使用した。試験片の長さは試験機
の容量を考慮して決められたものであって、技術的意味
はない。１１、１３は試験片１２の押し治具を示す。ま
たＢは荷重方向を示す。試験方法は、アムスラー引張試
験機１４に押し治具１１、１３をセットし、Ｂ方向に荷
重を加えて１５の位置に亀裂を生じさせるのである。そ
して、亀裂発生までの負荷のうち、最大荷重をもって圧
壊荷重と定め、その値を圧壊値と定義し、その時の試験
片のたわみをたわみ値と定義した。上記の方法で試験を
した結果を表４に示す。9 and 10 show the method of the crush test. For the crush test, a test piece 12 cut from a bushing to a length of L = 30 mm was used. The length of the test piece is determined in consideration of the capacity of the tester and has no technical meaning. Reference numerals 11 and 13 denote pushing jigs for the test piece 12. Further, B indicates the load direction. As the test method, the pushing jigs 11 and 13 are set in the Amsler tensile tester 14, and a load is applied in the B direction to cause a crack at the position of 15. Then, of the loads up to the occurrence of cracks, the maximum load was defined as the crush load, and that value was defined as the crush value, and the deflection of the test piece at that time was defined as the flexure value. Table 4 shows the results of the tests conducted by the above method.
【００３１】[0031]
【表４】 [Table 4]
【００３２】本発明品の圧壊特性は、（イ）の方法によ
る従来品とほぼ同等であるが、（ロ）および（ハ）の方
法による従来品よりは若干劣っている。しかしながら、
（イ）の方法は長年にわたり実用化されており、不具合
は発生していないことから、（イ）の方法による従来品
とほぼ同等の圧壊特性が得られる本発明の方法も実用に
供し得ると考えられる。The crushing property of the product of the present invention is almost the same as that of the conventional product prepared by the method (a), but slightly inferior to that of the conventional product prepared by the methods (b) and (c). However,
Since the method (a) has been put to practical use for many years and no trouble has occurred, the method according to the present invention, which provides almost the same crushing characteristics as the conventional product by the method (a), can be put to practical use. Conceivable.
【００３３】[0033]
【発明の効果】本発明によれば、次の効果が得られる。 （１） 履帯用ブッシング素材の材料に、高炭素低合金
鋼（重量％にしてＣ：０．５〜１．０％）を用いたの
で、表面の必要炭素量を確保するための浸炭を省略する
ことができ、熱処理コストを削減することができる。 （２） しかも、表面硬さ、耐摩耗性、靱性、圧壊強度
等の機械的性質において、従来方法と同等かそれ以上に
優れており、これらの機械的性質を低下させずに、上記
の熱処理コスト削減を達成することができる。According to the present invention, the following effects can be obtained. (1) High carbon low alloy steel (C: 0.5 to 1.0% in weight%) was used as the material for the track bushing material, so carburization for securing the required carbon amount on the surface was omitted. Therefore, the heat treatment cost can be reduced. (2) Moreover, the mechanical properties such as surface hardness, abrasion resistance, toughness, and crushing strength are equal to or better than those of the conventional method, and the heat treatment described above is performed without deteriorating these mechanical properties. Cost savings can be achieved.
【図１】一般の履帯の分解斜視図である。FIG. 1 is an exploded perspective view of a general crawler belt.
【図２】履帯用ブッシングの縦断面図である。FIG. 2 is a vertical cross-sectional view of a track bushing.
【図３】試験に供した履帯用ブッシング素材の各寸法を
表わす縦断面図である。FIG. 3 is a vertical cross-sectional view showing each dimension of the track bushing material used in the test.
【図４】（イ）、（ロ）、（ハ）の方法における浸炭層
の炭素量および本発明における高炭素低合金鋼の炭素量
である。FIG. 4 is the carbon content of the carburized layer in the methods (a), (b) and (c) and the carbon content of the high carbon low alloy steel in the present invention.
【図５】（イ）の方法で製造された履帯用ブッシングの
断面硬さである。FIG. 5 is a sectional hardness of a track bushing manufactured by the method (a).
【図６】（ロ）の方法で製造された履帯用ブッシングの
断面硬さである。FIG. 6 is a cross-sectional hardness of the track bushing manufactured by the method (b).
【図７】（ハ）の方法で製造された履帯用ブッシングの
断面硬さである。FIG. 7 is a cross-sectional hardness of a track bushing manufactured by the method (c).
【図８】本発明の方法で製造された履帯用ブッシングの
断面硬さである。FIG. 8 is a sectional hardness of a track bushing manufactured by the method of the present invention.
【図９】圧壊試験装置の要部正面図である。FIG. 9 is a front view of a main part of the crush test apparatus.
【図１０】図９の装置の側面図である。FIG. 10 is a side view of the device of FIG.
７ 履帯用ブッシング ７ａ 内周表面 ７ｂ 外周表面 7 Tracking bushing 7a Inner surface 7b Outer surface
Claims (1)
シング素材に、浸炭を施すことなく、素材に調質を施し
て該ブッシング素材の肉厚全体をソルバイト組織にする
第１の工程と、 該ブッシング素材をその軸線を中心にして回転させつ
つ、その外周側に高周波焼入れを施し、該ブッシング素
材に外周有効硬化層を形成する第２の工程と、 ブッシング素材をその軸線を中心にして回転させ、か
つ、前記外周側を液冷しつつ、その内周側に高周波焼入
れを施し、該ブッシング素材に内周有効硬化層を形成す
る第３の工程と、 前記工程の終了後、前記ブッシング素材を低温焼もどし
する第４の工程と、から成ることを特徴とする履帯用ブ
ッシングの製造方法。1. A first step in which a bushing material for a crawler belt made of high carbon low alloy steel is tempered without carburizing to make the entire thickness of the bushing material a sorbite structure. While rotating the bushing material about its axis, the second step of subjecting the bushing material to induction hardening on its outer periphery to form an outer peripheral effective hardened layer, and the bushing material about its axis A third step of rotating and liquid-cooling the outer peripheral side and subjecting the inner peripheral side to induction hardening to form an effective inner hardened layer on the bushing material; and after the step, the bushing A method for producing a track bushing, comprising a fourth step of tempering the material at a low temperature.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3271800A JPH0578746A (en) | 1991-09-25 | 1991-09-25 | Manufacture of bushing for crawler |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3271800A JPH0578746A (en) | 1991-09-25 | 1991-09-25 | Manufacture of bushing for crawler |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH0578746A true JPH0578746A (en) | 1993-03-30 |
Family
ID=17505031
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP3271800A Pending JPH0578746A (en) | 1991-09-25 | 1991-09-25 | Manufacture of bushing for crawler |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0578746A (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2755980A1 (en) * | 1996-11-14 | 1998-05-22 | Girardello Bruno | Heat treatment process for bearings |
| US6179936B1 (en) * | 1998-01-29 | 2001-01-30 | Topy Kogyo Kabushiki Kaisha | Method for heat-treating a hollow cylindrical workpiece |
| GB2388415A (en) * | 2002-04-10 | 2003-11-12 | Tsubakimoto Chain Co | Wear resistant chain |
| JP2009179869A (en) * | 2008-01-31 | 2009-08-13 | Tsuda Heat Treatment Co Ltd | Bush making |
| WO2017203804A1 (en) * | 2016-05-26 | 2017-11-30 | 株式会社小松製作所 | Bushing for hydraulic breaker and production method for same |
| JP2022548393A (en) * | 2019-09-26 | 2022-11-18 | キャタピラー インコーポレイテッド | high carbon steel track bushing |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6316314A (en) * | 1986-07-08 | 1988-01-23 | Takamisawa Saibaneteitsukusu:Kk | Uninterruptible power supply interface device |
| JPH01272719A (en) * | 1988-04-25 | 1989-10-31 | Komatsu Ltd | Bushing hardened to large depth and production thereof |
| JPH03166320A (en) * | 1989-11-22 | 1991-07-18 | Komatsu Ltd | Track bushing and its production |
-
1991
- 1991-09-25 JP JP3271800A patent/JPH0578746A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6316314A (en) * | 1986-07-08 | 1988-01-23 | Takamisawa Saibaneteitsukusu:Kk | Uninterruptible power supply interface device |
| JPH01272719A (en) * | 1988-04-25 | 1989-10-31 | Komatsu Ltd | Bushing hardened to large depth and production thereof |
| JPH03166320A (en) * | 1989-11-22 | 1991-07-18 | Komatsu Ltd | Track bushing and its production |
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2755980A1 (en) * | 1996-11-14 | 1998-05-22 | Girardello Bruno | Heat treatment process for bearings |
| US6179936B1 (en) * | 1998-01-29 | 2001-01-30 | Topy Kogyo Kabushiki Kaisha | Method for heat-treating a hollow cylindrical workpiece |
| GB2388415A (en) * | 2002-04-10 | 2003-11-12 | Tsubakimoto Chain Co | Wear resistant chain |
| GB2388415B (en) * | 2002-04-10 | 2005-05-11 | Tsubakimoto Chain Co | Wear resistant chain |
| JP2009179869A (en) * | 2008-01-31 | 2009-08-13 | Tsuda Heat Treatment Co Ltd | Bush making |
| WO2017203804A1 (en) * | 2016-05-26 | 2017-11-30 | 株式会社小松製作所 | Bushing for hydraulic breaker and production method for same |
| JP2017210659A (en) * | 2016-05-26 | 2017-11-30 | 株式会社小松製作所 | Bushing for hydraulic breaker and manufacturing method therefor |
| JP2022548393A (en) * | 2019-09-26 | 2022-11-18 | キャタピラー インコーポレイテッド | high carbon steel track bushing |
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