Translated from Japanese to English - www.onlinedoctranslator.com No.40(2023) mazda technical report Special feature:MAZDA MX-30 Rotary-EV 15 New rotary engine8CHigh speed chrome molybdenum for molds Development of plating method Development of High-Speed Chrome-Molybdenum Plating Method for New 8C Rotary Engine Masao Hayashi *1 Takamasa Sonoda *2 Kana Haruki *3 Masao Hayashi Takamasa Sonoda Kana Haruki Nobuhiro Takaba *Four Nobuhiro Takaba summary In rotary engines, the trochoidal surface of the sliding part of the rotor housing is plated with chromium molybdenum to improve wear resistance. The rotor housing has achieved wear resistance by ensuring a high-strength plating film through dense plating and by retaining a lubricating oil film in the oil pool grooves on the plating surface. This time, in order to revive the rotary engine, we applied a new plating method andC.O.2We worked on reducing this as an issue. Specifically, in the production process,6.5The plating process took many hours, and it also required an oil pool groove formation process using reverse electric treatment to maintain the oil film. Adding a catalyst to the plating solution increases the plating deposition efficiency and reduces the processing time by more than half of the conventional method.3There has been a method to form oil reservoir grooves at the same time as the plating process while reducing the time required, but it is possible to reduce the variation in the plating deposition rate on workpieces with complex shapes and obtain a uniform plating film as desired. was an issue in mass production. For this issue,CAEBy optimizing the electrode shape and processing conditions usingC.O.2of45% reduction. Abstract The trochoid surface of the rotary engine's rotor housing is coated with a chrome-molybdenum alloy plating for the purpose of wear resistance. Wear resistance is achieved by maintaining a high-strength plating film and retaining a lubricating oil in the oil retention grooves on the plating surface. In the revival of the rotary engine, e orts were made to apply a new plating method while addressing CO2reduction. The previous plating method required a lengthy plating processing time of 6.5 hours and an additional step of forming oil retention grooves through reverse electroplating. Although there had been a method proposal to reduce the processing time to 3 hours by adding a catalyst to the plating solution while forming oil retention grooves, achieving a uniform plating film on complexshaped workpieces remained a challenge for mass production. To address this issue, mass production was realized by utilizing CAE to optimize electrode shapes and processing conditions, significantly improving production e ciency, and reducing CO2emissions during the plating process by 45%. Key words:Materials, Catalyst, Addition, Surface treatment/plating, Strength/sti ness/rigidity/wear resi stance 1.Introduction Until now, the rotary engine, which is Mazda's unique technology,60It has developed. The rotary engine installed in this power generation unit is also designed to provide high output and high durability, just as before. To been under development for over a year. This time, we have developed a new improve durability, chromium molybdenum plating, which has wear power generation unit that takes advantage of the compact and high output resistance and low friction, is deposited on the trochoid surface, which is characteristics of this rotary engine.e-SKYACTIV R-EV the sliding part. Dense by slowly forming a plating film * 1〜Four Vehicle engineering department Painting, Trim & Final Assembly Engineering Dept. ― 84― No.40(2023) mazda technical report We have ensured wear resistance by forming a plain plating, and added low friction properties by forming oil pool grooves using reverse electric treatment. However, from an environmental perspective, the operation of plating processing equipment (6.5h), logistics between processes, and reverse electrical processing each require energy, and there was an urgent need to reduce energy consumption in order to achieve carbon neutrality. This time, we introduced a high-speed chrome plating method in which a catalyst is added to the plating solution.(1) By adopting this method, in addition to shortening the plating time and improving the Fig. 2 plating structure, we simultaneously solved the problem of reducing the additional 13B Conventional Process processing energy of reverse electric treatment, and addressed the issue of controlling variations in plating speed. This paper reports on the activities aimed at introducing the high-speed chrome plating method into mass production. 2.Functional integration of plating film After the rotor housing is made of aluminum with a steel plate layer cast and affixed to the inner surface, the inner surface of the trochoidal surface is ground at an engine processing factory, and then transported to a plating factory where it is plated with hard chrome. Traditional13Btype rotor housing (Fig. 1On the left), Fig. 3 after internal grinding after hard chrome plating, engine performance was 8C New Process ensured by transporting the product to the plating factory again and forming oil pool grooves using reverse electric treatment.13BMold processing processFig. 2 Shown below. In contrast,8Ctype rotor housing (Fig. 1The newly adopted highspeed chrome plating method (right) adds a catalyst to the plating solution and increases the current density during the plating process, thereby speeding up the plating process and at the same time forming oil pool grooves in the film. This is a plating process that significantly shortens the plating time and eliminates the Fig. 4 Surface after Grinding need for additional machining to form oil pool grooves.8CMold processing processFig. 3To,13Bmold and8CPhoto of the mold after internal grindingFig. 4 Shown below. In general, with this method, it has been found that the plating film 3.Main initiatives thickness and plating structure tend to be unstable, and reducing the variation in the plating film thickness and plating structure has been an issue for mass 3.1Construction of a plating surface observation system (quantification of plating production. To solve the problem, we first quantified the plating structure. Next, structure) we controlled the process factors (managing the plating solution components, Approx.150μmChromium plating is precipitated on the surface of the engine, controlling the plating solution flow rate, and controlling the electrode shape) to and within this film there are oil-sump grooves that play an important role in achieve the target plating film thickness and plating structure. guaranteeing engine performance. The size of this oil pool groove greatly affects the quality after internal grinding in the subsequent process. The number of oil sump grooves is1cmper approx. 1000Since the grooves were very small, the challenge was to select equipment and develop a measurement method that would enable highly accurate observation and measurement. To observe and measure oil pool grooves, it is necessary to place a lens perpendicular to the mass-produced workpiece and observe it, but the inside of the workpiece is approximately205mm(Fig. 5) and cannot be observed using commercially available microscopes. For this reason, we created a microscope that allows observation with a mirror attached to the tip of the lens, and designed and installed a device that can thoroughly observe all parts of the trochoid surface. The introduced microscopeFig. 6，7Shown below. This device can be used in photos taken (Fig. 8The number of oil pool grooves in the plating 13B 8C Fig. 1 film can be measured using image analysis (left). concrete Rotor Housing ― 85― No.40(2023) mazda technical report 3.2Control of plating deposition rate The plating solution used in high-speed chromium molybdenum plating of rotor housings is composed of chromic acid, sulfuric acid, sodium molybdate, catalyst, etc., and the plating quality varies greatly depending on conditions such as concentration, temperature, current density, and flow rate. Ru. Temperature is important for the hardness of the plating film, and chromic acid concentration and sulfuric acid concentration are important for the coverage of the plating film. In addition, the oil sump groove has a catalyst concentration (Fig. 9) and processing current value (Fig. 10) can be Fig. 5 controlled. Shape of Rotor Housing Fig. 9 Catalyst Concentration vs Oil Retention Groove Count Graph Fig. 6 Microscope System Fig. 10 Current Density vs Oil Retention Groove Count Graph It is also important to appropriately control the catalyst concentration in the plating solution. Differences in film structure due to differences in catalyst concentration in the Fig. 7 plating solutionFig. 11Shown below. The plating structure differs greatly depending on Observation of Inside Surface of Work the catalyst concentration in the plating solution. Fig. 8 Picture of Oil Retention Grooves in a Plating Film At the depth that is removed by internal grinding,1cmThe number of intersections in the observation image of the oil pool groove around (Fig. 8 Fig. 11 (right) can be read and calculated. In this way, we have constructed a system to Current Density and Plating Surface Structure quantitatively judge the quality of the plating process, and this has created a foundation for clarifying the control range of control factors and quality product conditions in mass production. Since the catalyst concentration changes gradually during the plating process, it is necessary to accurately and frequently control the catalyst concentration to ensure a uniform plating structure. Therefore, during mass production, quick and high ― 86― No.40(2023) mazda technical report After considering a method that could accurately measure and manage the catalyst concentration in the plating solution, we decided to adopt the ion chromatography method and deploy it on the line side. 3.3Plating solution circulation flow control Rotor housing plating equipment is shown below.Fig. 12The basic structure has not changed significantly since the beginning of rotor housing production.1 Because we wanted to plate more rotor housings at once, we assembled several workpieces into the plating equipment in a stacked state, and poured the plating solution from below into the small gap between the electrodes set in the center Fig. 14 Simulation of Work Surface Flow Velocity of the equipment and the workpieces. The equipment is designed to collect the Based on these results, we also incorporated into the equipment waste from the upper side of the feeder. The system reduces chromium ions by applying electricity while circulating the plating solution, depositing a chromium specifications a mechanism to adjust the flow rate of the plating solution within plating film on the trochoid surface. At this time, a large amount of oxygen is the stacked workpieces. In the verification on the actual machine,9Achieves the desired plating thickness on all stacked workpieces.150μmwas confirmed to be generated from the electrode surface (anode side) and hydrogen gas is precipitated. In fact, it was confirmed that the difference in film thickness generated from the workpiece surface (cathode side) (Fig. 13). decreased as the circulation flow rate was increased, proving that actively removing the gas generated during the plating deposition reaction is effective in making the plating deposition uniform.8CThe mold rotor housing plating equipment is shown below (Fig. 15). Fig. 12 Plating Equipment Configuration Fig. 15 8C Plating Equipment 3.4Simulation design of plating electrodes Through our efforts so far, we have found that reducing the difference in plating deposition rate depending on the location is important for ensuring the quality of the plating film. Therefore, in order to further improve quality, Toro worked on making the plating deposition rate uniform within the coid surface. We conducted a simulation analysis based on previous electrode design ideas, and8CWe designed a special plated electrode compatible with the type rotor Fig. 13 Plating Mechanism housing (Fig. 16，17). The generated gas is collected from the top together with the plating solution, but if the workpieces are stacked too high, the amount of gas adhering to the surface of the workpieces stacked at the top and the workpieces loaded at the bottom will be different. This results in differences in the plating film thickness and plating structure. We assumed that by recovering the gas generated during plating deposition through the plating solution circulation flow, we could reduce the difference in plating speed and reduce variations in plating film thickness and plating structure.CAEVerify the flow on the workpiece surface due to changes in circulating flow rate (Fig. 14), and determined the number of workpieces to be processed simultaneously and the plating solution Fig. 16 circulation flow rate. ― 87― Analytical Model Creation No.40(2023) mazda technical report Fig. 17 Analysis Result Fig. 20 Film Thickness Measurement Results As a result of comparing the film thickness as an index, it was confirmed that when a specially designed electrode was used, the condition matched the state determined by simulation analysis.1The difference in film thickness between two workpieces can be reduced by1/3It was reduced to 3.5Evolution of quality assurance system Through this activity, the relationship between plating film quality and manufacturing conditions, which are control factors, has become clear. Furthermore, as he went through the process of introducing mass production, he added control items during manufacturing, and found that the quality results could be statistically guaranteed. Furthermore, a two-dimensional barcode (Fig. 18) and stamp the workpiece.1Sheet1sheets and plating processing conditions (Fig. 19) and plating quality Fig. 21 Number of Oil Retention Groove confirmation results (Fig. 20，twenty one) has been put in place to enable registration and confirmation in the database. By recording and centrally managing the Four.effect manufacturing conditions and quality results of all mass-produced workpieces as data, By adopting a high-speed chromium molybdenum plating method, plating we have evolved a system that guarantees the quality of all workpieces. time can be reduced.6.5hfrom3.0hand eliminated the reverse electric treatment process after internal grinding. As a result, the annual61000kg-CO2 achieved a reduction in It was also confirmed that by reducing the wear of the plating film, the abrasion of the apex seal, which comes into contact with the sliding parts, was also reduced. Five.in conclusion Fig. 18 2D Barcode This unit was able to be commercialized through the collaboration and cooperation of many related departments, including development, materials, processing, plating, and assembly. While continuing this relationship, we will continue to work hard to develop attractive products that exceed customer expectations and make them happy. Finally, we would like to express our gratitude to all those involved in the development and production of high-speed chrome-molybdenum plating. References (1) Tanida et al.: Development of low-friction surface treatment for engine sliding parts. From,Mazda technical report,No.27，pp.148-152(2009 ) Fig. 19 Control Panel Log Data ― 88― No.40(2023) mazda technical report ■Author■ Masao Hayashi Takamasa Sonoda Kana Haruki Nobuhiro Takaba ― 89― 特集：MAZDA MX-30 Rotary-EV マツダ技報 No.40（2023） 新型ロータリーエンジン 8C 型向け高速クロムモリブデン めっき工法の開発 Development of High-Speed Chrome-Molybdenum Plating Method for New 8C Rotary Engine 15 林 政男 * 園田 1 Masao Hayashi 高場 宣弘 * 尊正 * 2 Takamasa Sonoda 春木 佳奈 * 3 Kana Haruki 4 Nobuhiro Takaba 要 約 ロータリーエンジンにおいて，ローターハウジング摺動部のトロコイド面には耐摩耗性向上を目的としたク ロムモリブデンめっきを施している。ローターハウジングは緻密なめっき形成による高強度なめっき皮膜の確 保とめっき表面の油だまり溝への潤滑油膜の保持により耐摩耗性を確保してきた。今回，ロータリーエンジン の復活にあたり，新しいめっき工法を適用しつつ CO2 低減を課題として取り組んだ。具体的には生産工程にお いて，6.5 時間ものめっき処理時間を要し，更に油膜保持のため逆電処理による油だまり溝形成工程を要して いた。めっき液中に触媒を添加することでめっきの析出効率を高め，処理時間を従来の半分以下の 3 時間に短 縮しつつ，めっき処理と同時に油だまり溝を形成する工法案はあったが，複雑形状のワークへのめっき析出速 度のバラツキを低減し，ねらいどおりの均一なめっき皮膜を得ることが量産化の課題であった。この課題に対 し，CAE を活用して電極形状と処理条件を最適化することにより量産化を実現し，生産効率を大きく向上させ， 同時にめっき処理の際に発生する CO2 を 45％低減することができた。 Abstract The trochoid surface of the rotary engine’s rotor housing is coated with a chrome-molybdenum alloy plating for the purpose of wear resistance. Wear resistance is achieved by maintaining a high-strength plating film and retaining a lubricating oil in the oil retention grooves on the plating surface. In the revival of the rotary engine, efforts were made to apply a new plating method while addressing CO2 reduction. The previous plating method required a lengthy plating processing time of 6.5 hours and an additional step of forming oil retention grooves through reverse electroplating. Although there had been a method proposal to reduce the processing time to 3 hours by adding a catalyst to the plating solution while forming oil retention grooves, achieving a uniform plating film on complex-shaped workpieces remained a challenge for mass production. To address this issue, mass production was realized by utilizing CAE to optimize electrode shapes and processing conditions, significantly improving production efficiency, and reducing CO2 emissions during the plating process by 45%. Key words：Materials, Catalyst, Addition, Surface treatment/plating, Strength/stiffness/rigidity/wear resi stance を開発した。 1. はじめに 今回の発電ユニットに搭載されるロータリーエンジン マツダ独自の技術であるロータリーエンジンは，これ も従来同様，高出力かつ高耐久の機能を追求している。 のロータリーエンジンの特徴であるコンパクトで高出力 性と低摩擦性を備えたクロムモリブデンめっきを析出さ まで 60 年余りにわたり開発を進めてきている。今回，こ な特性を活かした新たな発電ユニット e-SKYACTIV R-EV *1～4 車両技術部 Painting, Trim & Final Assembly Engineering Dept. 耐久性の向上のため摺動部となるトロコイド面に耐摩耗 せている。ゆっくりとめっき皮膜を形成することで緻密 ― 84 ― マツダ技報 No.40（2023） なめっきを形成して耐摩耗性を確保し，逆電処理による 油だまり溝形成を行うことで低摩擦性を付与してきた。 しかしながら環境側面では，めっき処理設備の稼働 （6.5h），工程間の物流，逆電処理のそれぞれでエネル ギーを要しており，カーボンニュートラルの達成に向け 消費エネルギーの低減が急務であった。今回めっき液中 に触媒を添加してめっきを行う高速クロムめっき工法 （1） を採用することにより，めっき時間の短縮とめっき構造 の改善に加え，逆電処理という追加加工エネルギーの削 Fig. 2 13B Conventional Process 減を同時に解決し，その課題であるめっき速度のバラツ キ制御に取り組んだ。本稿では，高速クロムめっき工法 の量産導入にむけた活動内容について報告する。 2. めっき皮膜の機能集約 ローターハウジングはアルミ材の内面に鉄板層を鋳込 貼付した後，エンジン加工工場にてトロコイド面の内面 研削加工を行い，めっき工場に搬入し硬質クロムめっき を行っている。従来の 13B 型ローターハウジング（Fig. 1 左）では，硬質クロムめっき処理後の内面研削後に， Fig. 3 8C New Process 再度めっき工場に搬入し逆電処理にて油だまり溝の形成 を行うことでエンジン性能を確保してきた。13B 型の加 工工程を Fig. 2 に示す。これに対し，8C 型ローターハウ ジング（Fig. 1 右）で新たに採用した高速クロムめっき 工法は，めっき液に触媒を添加し，電流密度を高めて めっき処理することで，めっき処理速度を速めると同時 に皮膜中に油だまり溝を形成させることができるため， めっき時間の大幅な短縮かつ油だまり溝形成のための追 Fig. 4 Surface after Grinding 加加工の廃止が可能となるめっき処理法である。8C 型 の加工工程を Fig. 3 に，13B 型及び 8C 型の内面研削後 3. 主要取り組み の写真を Fig. 4 に示す。 一般的にこの工法では，めっき膜厚とめっき構造がバ 3.1 めっき表面観察システムの構築（めっき構造定 構造のバラツキを低減することが量産化の課題であった。 めっき後のワークには約 150μ m のクロムめっきが析 ラツキやすいことがわかっており，めっき膜厚とめっき 量化） 課題解決に向けて，めっき構造の定量化をまず行った。 出されており，この皮膜中にはエンジン性能保証のため 工程因子の制御（めっき液成分管理，めっき液流量制御， だまり溝の大きさは後工程の内面研削加工後の品質に大 次にねらいのめっき膜厚とめっき構造を実現するための 電極形状の制御）を行った。 に重要な役割となる油だまり溝が存在している。この油 きく影響する。この油だまり溝の本数は 1cm あたり約 1000 本と，とても細かい溝であることから，高精度で 観察測定できる機器の選定及び測定方法の構築が課題で あった。油だまり溝の観察測定は，量産ワークに対して 垂直にレンズをあてて観察する必要があるが，ワークの 内側は約 205mm（Fig. 5）しかなく，市販されている顕 微鏡やマイクロスコープでは観察することができない。 このためレンズ先端にミラーを取付けた状態で観察する 仕組みのマイクロスコープを製作しトロコイド面の全て の部位を隈なく観察できる装置を設計・導入した。導入 13B 8C Fig. 1 Rotor Housing したマイクロスコープを Fig. 6，7 に示す。 この装置は撮影した写真（Fig. 8 左）から画像解析に てめっき皮膜中の油だまり溝の数を測定できる。具体的 ― 85 ― マツダ技報 No.40（2023） 3.2 めっき析出速度のコントロール ローターハウジング高速クロムモリブデンめっきで使 用しているめっき液は，クロム酸や硫酸，モリブデン酸 ナトリウム，触媒などから構成されており，濃度や温度， 電流密度，流量等の状況によりめっき品質は大きく変わ る。めっき皮膜の硬さに対しては温度が重要であり， めっき皮膜の付きまわり性はクロム酸濃度や硫酸濃度が 重要である。また油だまり溝は触媒濃度（Fig. 9）と処理 電流値（Fig. 10）で制御できる。 Fig. 5 Shape of Rotor Housing Fig. 9 Catalyst Concentration vs Oil Retention Groove Count Graph Fig. 6 Microscope System Fig. 10 Current Density vs Oil Retention Groove Count Graph また，めっき液中の触媒濃度を適切に管理することが 重要である。めっき液中の触媒濃度の違いによる皮膜構 造の違いを Fig. 11 に示す。めっき液中の触媒濃度の違い によりめっき構造は大きく異なる。 Fig. 7 Observation of Inside Surface of Work Fig. 8 Picture of Oil Retention Grooves in a Plating Film には内面研削加工にて削り取られる深さでの 1cm あたり の油だまり溝を観察画像中の交点数（Fig. 8 右）から読 取り算出できるようになっている。このようにめっき処 Fig. 11 理工程の品質を定量的に判定する仕組みを構築し，これ により量産における制御因子の管理幅と良品条件を明確 にする基盤ができた。 Current Density and Plating Surface Structure 触媒濃度はめっき処理工程において徐々に変化するた め，めっき構造の均一化のために，触媒濃度を精度よく 頻繁に管理する必要がある。そこで量産中，迅速かつ高 ― 86 ― マツダ技報 No.40（2023） 精度にめっき液中の触媒濃度を測定・管理できる方法を 検討した結果，イオンクロマトグラフ法を採用し，ライ ンサイドに配備することとした。 3.3 めっき液循環流量コントロール ローターハウジングめっき設備は下記 Fig. 12 に示す構 造で，ローターハウジング生産開始時から基本構造は大 きく変わっていない。1 度でより多くのローターハウジ ングをめっき処理したいため，ワークを数枚積み重ねた 状態でめっき設備に組付し，設備中央にセットされている Fig. 14 電極とワークのわずかな隙間に下側からめっき液を送り込 み上側から回収する仕組みの設備としている。めっき液を 循環しながら通電することでクロムイオンを還元し，トロ コイド面にクロムめっき皮膜を析出させる仕組みである。 この時，電極表面（陽極側）からは酸素，ワーク表面 （陰極側）からは水素ガスが大量に発生する（Fig. 13）。 Simulation of Work Surface Flow Velocity また，この結果から数段積み重ねたワーク内のめっき 液流量を調整する機構を設備仕様に織り込んだ。実機で の検証では，9 段積みされたワークの全てでねらいどお りのめっき膜厚 150μ m が析出されていることを確認で きた。実際に循環流量を増やすほど膜厚差が少なくなる ことが確認でき，めっき析出反応で発生するガスを積極 的に離脱させることがめっき析出の均一化に効果的であ ることが立証できた。8C 型ローターハウジングめっき 設備を以下に示す（Fig. 15）。 Fig. 12 Plating Equipment Configuration Fig. 15 3.4 8C Plating Equipment めっき用電極のシミュレーション設計 ここまでの取り組みで，部位によるめっき析出速度の 差を低減することが，めっき皮膜の品質確保に重要であ ることが分かった。そこで更なる品質改善のため，トロ コイド面内のめっき析出速度均一化に取り組んだ。これ までの電極設計の考えを基にシミュレーション解析を行 Fig. 13 い，8C 型ローターハウジングに対応した専用めっき電 極の設計を行った（Fig. 16，17）。 Plating Mechanism 発生したガスはめっき液と一緒に上側から回収される が，ワークを高く積み重ねて過ぎた場合には，上部に積 み込まれたワークと下部に積み込まれたワークで表面の ガスの付着量が異なり，めっき膜厚とめっき構造に差が 生じてしまう。めっき析出時に発生するガスをめっき液 循環流により回収することで，めっき速度の差を低減し， めっき膜厚とめっき構造のバラツキが低減できると仮定 し，CAE により循環流量変化によるワーク表面の流れを 検証（Fig. 14）し，ワークの同時処理数とめっき液循環 流量を決定した。 ― 87 ― Fig. 16 Analytical Model Creation マツダ技報 Fig. 17 No.40（2023） Analysis Result Fig. 20 膜厚を指標に比較した結果，専用設計した電極を使っ Film Thickness Measurement Results た場合，シミュレーション解析で求められた状態と合致 していることが確認でき，1 枚のワークの中での膜厚差 を従来の 1/3 に低減した。 3.5 品質保証システムの進化 本活動にて，めっき皮膜品質と制御因子である製造条 件の関係が明確になってきた。また実際に量産導入して いく中で製造時の管理項目を追加し，品質結果も統計的 に品質保証できることが分かった。更に，ワークに二次 元バーコード（Fig. 18）を打刻し，ワーク 1 枚 1 枚と， めっき処理条件（Fig. 19）及びめっき品質確認結果（Fig. Fig. 21 Number of Oil Retention Groove 20，21）をデータベースに登録，確認できるシステムを 整備した。量産ワーク全数の製造条件と品質結果をデー 4. 効果 ターとして残し，一元管理することで，全てのワークを 品質保証するようシステムを進化させた。 高速クロムモリブデンめっき工法の採用により，めっ き時間を 6.5h から 3.0h と短縮し，かつ内面研削後の逆 電処理工程を廃止した。この結果，年間 61000kg-CO2 の削減を実現した。また，めっき皮膜の低摩耗化により， 摺動部で接触するアペックスシールの摩耗性もねらいど おりに低減できていることが確認できた。 5. おわりに Fig. 18 2D Barcode 本ユニットは開発，素材，加工，めっき，組立など多 くの関連部門の連携と協力によって商品化を実現するこ とができた。この関係性を継続しながら今後もお客様の 期待を上回り，喜んでいただけるような魅力ある商品開 発に尽力していく所存である。最後に，高速クロムモリ ブデンめっきの開発・生産にご協力いただいた全ての関 係者の皆様に感謝の意を表します。 参考文献 （1） 谷田ほか：エンジン摺動部材の低摩擦表面処理の開 発，マツダ技報，No.27，pp.148-152（2009） Fig. 19 Control Panel Log Data ― 88 ― マツダ技報 No.40（2023） ■著 者■ 林 政男 園田 尊正 春木 佳奈 高場 宣弘 ― 89 ―