JPH01240621A - Shape steel for forklift mast having excellent wear resistance - Google Patents
Shape steel for forklift mast having excellent wear resistanceInfo
- Publication number
- JPH01240621A JPH01240621A JP63064978A JP6497888A JPH01240621A JP H01240621 A JPH01240621 A JP H01240621A JP 63064978 A JP63064978 A JP 63064978A JP 6497888 A JP6497888 A JP 6497888A JP H01240621 A JPH01240621 A JP H01240621A
- Authority
- JP
- Japan
- Prior art keywords
- mast
- wear resistance
- shape steel
- wear
- steel
- 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
- 229910000831 Steel Inorganic materials 0.000 title claims abstract description 36
- 239000010959 steel Substances 0.000 title claims abstract description 36
- 238000005255 carburizing Methods 0.000 abstract description 4
- 238000000034 method Methods 0.000 abstract description 3
- 238000010791 quenching Methods 0.000 abstract description 2
- 230000000171 quenching effect Effects 0.000 abstract description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 6
- 229910052799 carbon Inorganic materials 0.000 description 6
- 238000005299 abrasion Methods 0.000 description 4
- 238000003466 welding Methods 0.000 description 4
- 229910000975 Carbon steel Inorganic materials 0.000 description 3
- 230000007423 decrease Effects 0.000 description 3
- 229910000734 martensite Inorganic materials 0.000 description 3
- 239000000463 material Substances 0.000 description 3
- 238000005496 tempering Methods 0.000 description 3
- 238000011282 treatment Methods 0.000 description 3
- 239000010962 carbon steel Substances 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000005121 nitriding Methods 0.000 description 2
- 229910001562 pearlite Inorganic materials 0.000 description 2
- 238000012360 testing method Methods 0.000 description 2
- 229910000677 High-carbon steel Inorganic materials 0.000 description 1
- 230000002159 abnormal effect Effects 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 238000005275 alloying Methods 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 229910052804 chromium Inorganic materials 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 238000005098 hot rolling Methods 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 229910052759 nickel Inorganic materials 0.000 description 1
- 229910052758 niobium Inorganic materials 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 239000011435 rock Substances 0.000 description 1
- 239000004575 stone Substances 0.000 description 1
- 229910052720 vanadium Inorganic materials 0.000 description 1
- 229910000859 α-Fe Inorganic materials 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
- Forklifts And Lifting Vehicles (AREA)
- Solid-Phase Diffusion Into Metallic Material Surfaces (AREA)
Abstract
Description
【発明の詳細な説明】
（産業上の利用分野）
本発明はフォークが内外の二重マスト三重マストなどを
用いてローラーを介して上下動する構造の重量物運搬用
フォークリフターのマスト用形鋼に関するものである。Detailed Description of the Invention (Industrial Application Field) The present invention relates to a shaped steel for the mast of a forklifter for transporting heavy objects, in which the fork moves up and down via rollers using an inner and outer double mast, triple mast, etc. It is related to.
（従来の技術と発明が解決しようとする課題）産業運搬
機器の分野において、重要な役割を占めるフォークリフ
トは、近年より大型化・高性能化が指向されている。そ
れに伴って、重荷重を受けるフォークリフトマスト用形
鋼には主に“摩耗”に伴う以下の如き問題点が発生して
いた。(Problems to be solved by conventional techniques and inventions) Forklifts, which play an important role in the field of industrial transportation equipment, are becoming larger and more sophisticated in recent years. Along with this, the following problems have arisen mainly due to "wear" in the steel sections for forklift masts that are subjected to heavy loads.
■ ローラーと接触する部分で、摩耗剥離片が脱落して
運転者の目に入る。■ At the point where it comes into contact with the roller, worn pieces fall off and get into the driver's eyes.
■ 摩耗によるマスト用形鋼の板厚減少が大きいため、
ローラーとマスト用形鋼の間のすき間が大きくなり、積
荷の上げ・下げ時に騒音が発生する。■ Due to the large reduction in the thickness of the mast section steel due to wear,
The gap between the rollers and the mast section steel increases, causing noise when lifting and lowering loads.
■ 摩耗による板厚減少で、衝撃荷重が発生し、マスト
ビン溶接部から疲労き裂が発生する。■ As the plate thickness decreases due to wear, impact loads occur, causing fatigue cracks to occur at the mast bin welds.
以上のように問題点は全てローラーと接触するマスト用
形鋼の耐摩耗性に起因しており、本発明者らは、この問
題点の解決のために、マスト用形鋼の耐摩耗性改善策に
ついて検討を行った。すなわち、従来のマスト用形ｍ
（５４５Ｃ）ならびに構造用炭素鋼５１５Ｇから５５８
Ｇについては、炭素含有量を変化した熱間圧延鋼材およ
びこれら構造用炭素鋼にＶやＮ、 Ｎｂ、 Ｃｒおよび
Ｎｉ等の合金元素を微量添加して機械的性質を向上した
熱間圧延鋼材の計２０種類について、西原式摩耗試験機
により実験室的に耐摩耗性の相対比較を行った。その結
果、フェライト・パーライト組織を主体とする熱間圧延
鋼材の場合、耐摩耗性は機械的性質や結晶粒度の大小と
は何ら相関なく、炭素含有量によってほぼ一義的に決ま
ることを見い出した。すなわち、高炭素鋼材はど耐摩耗
性が優れていることを明らかにした。したがって、炭素
含有量が０．３３％から０．４５％である従来マスト用
形鋼の耐摩耗性を改善するため辷は、さらに炭素含有量
を増す必要性のあることがわかった。ところが、従来マ
スト用形鋼ではすでに炭素含有量が高いため溶接性が悪
く、溶接時に余熱を行うなど溶接施工性にも問題があり
、さらに溶接割れやマルテンサイトなど異常組織の発生
など溶接性を一層悪くし、また耐疲労性にも悪影響があ
ることがわかった。そこで溶接性を損なうことなく、耐
摩耗性を一層向上する方策について種々検討した結果、
ローラーと接触するマスト用形鋼部分の組織を、従来の
フェライト・パーライトからマルテンサイトや焼もどし
マルテンサイトあるいは窒化合金層あるいは浸炭層など
高硬質化組織にする方法が最善であることがわがフた。As mentioned above, all of the problems are caused by the wear resistance of the mast section steel that comes into contact with the rollers.In order to solve this problem, the present inventors aimed to improve the wear resistance of the mast section steel. We considered possible measures. In other words, the conventional mast shape m
(545C) and structural carbon steel 515G to 558
Regarding G, hot-rolled steel materials with varying carbon content and hot-rolled steel materials with improved mechanical properties by adding trace amounts of alloying elements such as V, N, Nb, Cr, and Ni to these structural carbon steels. A total of 20 types were compared in terms of abrasion resistance in a laboratory using a Nishihara type abrasion tester. As a result, they found that in the case of hot-rolled steel materials with a ferrite-pearlite structure as their main structure, wear resistance has no correlation with mechanical properties or grain size, and is almost uniquely determined by carbon content. In other words, it was revealed that high carbon steel has excellent wear resistance. Therefore, it has been found that in order to improve the wear resistance of conventional mast section steel, which has a carbon content of 0.33% to 0.45%, it is necessary to further increase the carbon content of the shaft. However, conventional shaped steel for masts already has a high carbon content, which has poor weldability, and there are also problems with welding workability, such as the need for residual heat during welding.Additionally, there are problems with weldability, such as weld cracks and abnormal structures such as martensite. It was found that the fatigue resistance was further deteriorated and the fatigue resistance was also adversely affected. After considering various measures to further improve wear resistance without impairing weldability, we found that:
We believe that the best method is to change the structure of the section steel for the mast that comes into contact with the rollers from the conventional ferrite/pearlite to a highly hardened structure such as martensite, tempered martensite, nitrided alloy layer, or carburized layer. .
（課題を解決するための手段）・
本発明は上記知見に基づいてなされたもので、その主旨
とするところは、摩耗が問題となるローラーと接触する
マスト石形鋼部分を局部的に焼入れや焼入れ・焼もどし
あるいは浸炭あるいは窒化処理などによってその他の部
分より高硬質化を行うものであり、これにより、マスト
用形鋼の耐摩耗性が著しく向上し、摩耗による剥離片の
発生を防止でき、さらに摩耗による板厚減少が非常に少
ないために、騒音の発生も防止し、かつ、衝撃荷重も軽
減した耐摩耗性の優れたフォークリフトマスト用形鋼を
提供するものである。(Means for Solving the Problems) The present invention has been made based on the above findings, and its main purpose is to locally harden the mast stone section that comes into contact with the rollers where wear is a problem. It is made harder than other parts by quenching, tempering, carburizing, or nitriding, which significantly improves the wear resistance of the mast section steel and prevents the formation of flakes due to wear. Furthermore, the present invention provides a section steel for forklift masts with excellent wear resistance, which prevents the generation of noise and reduces impact loads because the plate thickness decreases due to wear is extremely small.
（作 用） 以下、本発明について図面を用いて詳細に説明する。(For writing) Hereinafter, the present invention will be explained in detail using the drawings.
第１図は代表的なインナーマスト用形鋼の横断面形状を
、第２図は代表的なアウターマスト用形鋼の横断面形状
を示す。図中の斜線部分表面はローラーと接触する個所
で、これらの部分の表面において摩耗による剥離片の発
生や、摩耗による板厚減少等で騒音が発生したり、衝撃
荷重が発生する問題点があった。そこで本発明ではこれ
らローラーと接触する第１歯中のＡ。FIG. 1 shows the cross-sectional shape of a typical inner mast section steel, and FIG. 2 shows the cross-sectional shape of a typical outer mast section steel. The shaded surfaces in the figure are the areas that come into contact with the rollers, and there are problems such as the generation of peeling pieces due to wear on the surfaces of these areas, the reduction of plate thickness due to wear, etc., which can cause noise and impact loads. Ta. Therefore, in the present invention, A in the first tooth that contacts these rollers.
ＢおよびＣ１第２図中のＤおよびＥ部分の表面を含む斜
線部分を局部的にその他の部分より高硬質化することに
より、耐摩耗性を向上させるものである。高硬質化の方
法としては焼入れまたは焼入れ・焼もどしあるいは浸炭
や窒化などを用いることができる。また高硬質化する斜
線部分は表面下の塑性変形深さを考慮して、表面以下３
ｍｍ程度の深さまでが経済性も加味して最適であるが、
表面以下３ｍｍより硬質化層が浅くても深くても特に耐
摩耗性が低下するようなことはない。ただ硬質化層が０
．５ｍｍ以下と極端に浅い場合には硬質化層以下の深さ
部分が圧縮塑性変形して板厚減少が起こるので好ましく
ない。Abrasion resistance is improved by locally making the shaded areas including the surfaces of parts D and E in FIG. 2 more hard than other parts. Hardening, hardening/tempering, carburizing, nitriding, or the like can be used to increase the hardness. In addition, the diagonally shaded area where the hardness increases is 3.3 mm below the surface, taking into account the depth of plastic deformation below the surface.
A depth of about mm is optimal considering economic efficiency, but
Even if the hardened layer is shallower or deeper than 3 mm below the surface, there is no particular decrease in wear resistance. However, the hardening layer is 0
．． If the depth is extremely shallow, such as 5 mm or less, the depth below the hardened layer will undergo compressive plastic deformation, resulting in a reduction in plate thickness, which is not preferable.
（実 施 例） 以下具体的実施例について説明する。(Example) Specific examples will be described below.
機械構造用炭素鋼５２５Ｇを用いて、インナーマスト用
形鋼およびアウターマスト用形鋼を熱間圧延で製造し、
各々ローラーと接触する部分を第１表に示す条□件によ
り高硬質化処理を行った。その結果、表面硬さはＨｖ３
０Ｑ〜７４０が得られ、硬化質深さは焼入れおよび焼入
れ・焼もどし処理で３ｍｍ〜１４ｍｍ、浸炭処理で０．
５ｍｍ〜１．１ｍｍである。本発明マスト用形鋼のうち
、摩耗の多いインナーマスト用形鋼について、実使用条
件を再現できる試験機に組込み、実機摩耗試験を行った
。その結果を第２表に示す。本発明のマスト用形鋼は２
０００ｋｇの荷重で、１０万回繰返し数後でも従来マス
ト用形鋼に比較して摩耗量が極めて少なく、剥離片の発
生や騒音発生もなく、またマストピン溶接部からの疲労
き裂発生も見られず、非常に優れた耐摩耗性を示す。ま
た、本発明のマスト用形鋼は従来マスト用形鋼よりも低
炭素であるため、溶接時に予熱の必要がなく、溶接作業
性も優れている特徴を有する。Using 525G carbon steel for machine structures, we manufacture inner mast section steel and outer mast section steel by hot rolling,
The parts in contact with the rollers were each subjected to hardening treatment under the conditions shown in Table 1. As a result, the surface hardness was Hv3
0Q to 740 was obtained, and the hardened depth was 3 mm to 14 mm in hardening and hardening/tempering treatments, and 0.0 in carburizing treatment.
It is 5 mm to 1.1 mm. Among the shaped steels for masts of the present invention, the shaped steels for inner masts, which tend to wear frequently, were incorporated into a testing machine that can reproduce actual usage conditions, and an actual machine wear test was conducted. The results are shown in Table 2. The mast section steel of the present invention is 2
Even after 100,000 repetitions under a load of 1,000 kg, the amount of wear is extremely small compared to conventional mast section steel, there are no peeling pieces or noise, and no fatigue cracks were observed from the mast pin welds. It also exhibits excellent abrasion resistance. Furthermore, since the mast section steel of the present invention has lower carbon than conventional mast section steels, it does not require preheating during welding and has excellent welding workability.
第１表
（発明の効果）
本発明は以上説明した如く、摩耗が問題となるローラー
と接触するマスト用形鋼部分を局部的に他部分より硬質
化したものであり、これによりマスト用形鋼の耐摩耗性
が著しく向上し、摩耗による剥離片の発生を有効に防止
でき、さらに摩耗による板厚減少が非常に少ないため、
騒音の発生も防止でき、かつ、衝磐荷重も軽減する等顕
著な効果を示すものである。Table 1 (Effects of the Invention) As explained above, the present invention is a method in which the section of mast section steel that comes into contact with the roller, where wear is a problem, is locally made harder than other sections. The wear resistance of the steel sheet has been significantly improved, and the generation of peeling pieces due to wear can be effectively prevented, and the reduction in plate thickness due to wear is extremely small.
It shows remarkable effects such as preventing the generation of noise and reducing the load on the rock.
第１図、第２図は夫々代表的なインナーマスト用形鋼及
びアウターマスト用形鋼の横断面図である。
Ａ、Ｂ、Ｃ，Ｄ、Ｅ・・・局部的に他部分より硬質化す
る部分。
第１図
硬質化する部分
第２図FIGS. 1 and 2 are cross-sectional views of typical inner mast section steel and outer mast section steel, respectively. A, B, C, D, E... Parts that are locally harder than other parts. Figure 1: Hardening part Figure 2
Claims (1)
分を局部的にその他の部分より高硬質化することを特徴
とする耐摩耗性の優れたフォークリフトマスト用形鋼1. Shaped steel for forklift masts with excellent wear resistance, characterized by locally making the section of forklift mast section steel that comes into contact with the rollers harder than other parts.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63064978A JPH01240621A (en) | 1988-03-18 | 1988-03-18 | Shape steel for forklift mast having excellent wear resistance |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63064978A JPH01240621A (en) | 1988-03-18 | 1988-03-18 | Shape steel for forklift mast having excellent wear resistance |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH01240621A true JPH01240621A (en) | 1989-09-26 |
Family
ID=13273649
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP63064978A Pending JPH01240621A (en) | 1988-03-18 | 1988-03-18 | Shape steel for forklift mast having excellent wear resistance |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH01240621A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115990808A (en) * | 2023-03-21 | 2023-04-21 | 山东新高智能装备有限公司 | Intelligent multilayer angle steel discharging control center |
-
1988
- 1988-03-18 JP JP63064978A patent/JPH01240621A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115990808A (en) * | 2023-03-21 | 2023-04-21 | 山东新高智能装备有限公司 | Intelligent multilayer angle steel discharging control center |
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