1 22, 2005

第14回：「タイヤのバースト」

このワークショップでは毎回さまざまな話題を取り上げるので、いろいろ知らなかったことが自然にわかって勉強になります。

自動車のタイヤには強度と耐摩耗性向上のためカーボンブラックという炭素微粒子が成分比で４分の１以上混入されており、大型トラックの巨大なタイヤでは重量比で半分以上がカーボンブラックだということです。

リンゴはなぜ木から落ちるかという疑問をもったニュートンさんは偉い人でしたが、自動車のタイヤはなぜみんな真っ黒かという質問をする小学生は先生にほめられることでしょう。


【課題文】
大型トラックのタイヤがバースト使い方が悪いのか，製造欠陥か

高速道路走行中に，大型トラックの右前輪タイヤが突然バースト（破裂）した。その結果，トラックは急に右に舵を取られて，中央分離帯に衝突し大破した。タイヤメーカーの検証結果では，事故原因はタイヤの空気圧不足となっている。ところが，問題のタイヤは通常のバーストでは考えられない損傷状態を示していた。

＜中略＞

このタイヤは，事故が起きる19日前に交換したばかりである。トレッド溝も17.2mm残っており，走行に支障を来すような磨耗レベルでは全くない。

このタイヤのメーカーが，事故タイヤを検証した結果を報告しているが，それによると「トレッド面のゴムとその下のスチールベルトの間で生じたはく離が，タイヤのオーバーヒートによって進行し，タイヤ全周に達した時点でバーストに至った」ということである。オーバーヒートの原因については「速度の出し過ぎか過積載，タイヤ空気圧不足のいずれか。特定は難しいが，タイヤの空気圧不足の可能性が最も高い」とし，「製造上の不具合はなかった」という結論を下している。

＜中略＞

タイヤのゴム部分は，接地面のトレッドとサイドウオール，それらの境目であるショルダに分けて考えることができる。トレッドは路面から大きな反力を受けるので，トレッド踏面の裏側にはスチールベルトを数層積み重ねて剛性を高めている。これは，サイドウオールは緩衝のためにしなやかさを要するが，路面を踏むトレッド面は路面の突起でも容易には裂けない頑丈さが必要だからである。

バーストしたタイヤを外周方向から見ると，左右のショルダに最も近いトレッド帯を1列だけ残して，トレッド面の中央部が最も外側のベルトと一緒に，ほぼ全周にわたってはがれている。そして，一部分はベルトにとどまらずその内側のカーカスも含めて半径方向にも壊滅的に断裂している。

一般的に，オーバーヒートによるタイヤのバーストは，ショルダ部に起こる。ショルダ部でカーカスが円周方向に切断されるのだ。これは，ショルダ部がタイヤの中で最も応力が集中する場所であり，接地ごとの変形が大きく発熱量が多い所だからである。広い意味で「疲労破壊は切り欠き部分に集中して起こる」の原則に従うということだ。

＜後略＞


D&M 日経メカニカル2004年2月（No. 593）より

[テキスト1]

使い方が悪いのか，製造欠陥か

高速道路走行中に，大型トラックの右前輪タイヤが突然バースト（破裂）した。その結果，トラックは急に右に舵を取られて，中央分離帯に衝突し大破した。タイヤメーカーの検証結果では，事故原因はタイヤの空気圧不足となっている。ところが，問題のタイヤは通常のバーストでは考えられない損傷状態を示していた。

[訳例1]

Large Truck Tire Blowout: Who's to Blame: a Bad Driver or the Manufacturer?

The front right wheel tire of a large truck suddenly burst (ruptured) while driving on the highway. This caused the truck to veer suddenly to the right, crash into the median strip, resulting in a wreck that ultimate1y totaled the vehicle. The results of the tire manufacturer's investigation place the blame on insufficient air pressure in the tires. However, the damage to the tire in question was too severe to have been caused by a simple blowout.
□ a Bad Driver
この不定冠詞で「わるい運転のしかた」という意味が言外に伝わる。

[訳例2]

(1) A Truck Tire Blew Out
--Whose fault was it; user or manufacturer?

When a large truck was driving on an expressway, (2) a tire on the right front wheel suddenly blew out. The blowout caused (3) a strong pull toward right, (4) let the truck hit the median, and wrecked (5) the truck. The manufacturer of the tire made an investigation (6) on the tire and reported that the cause of the accident was insufficient air pressure in the tire. However, the (7) damage of the tire was quite different from the damage in most tire blowouts.

  1. Truck Tire Blowout
    blow out は主に名詞（blowout）で使う。動詞ではburstやrapture などが一般的。
  2. the right front wheel tire
  3. a strong pull toward right → the truck to veer to the right
  4. let 削除。
  5. the truck 削除。
  6. on the tire 削除。
  7. damage of → damage to

[訳例3]

Heavy (1) Truck's Tire Blows Out
(2) Who is to Blame; Driver or Manufacturer?

A heavy truck's front tire suddenly blew out while (3) rolling on an expressway. As the result, the truck abruptly veered to the right, crashed into the median, and (4) smashed up. The manufacturer of the tire inspected the tire and concluded that the accident (5) resulted from insufficient air pressure in the tire. The tire in question, however, showed severe damage that an ordinary tire blow-out would not (6) bring about.

  1. Trucks Tire → Truck Tire
  2. Who's to Blame
  3. rolling → driving
  4. smashed up → was wrecked
  5. resulted from → was a result of
  6. bring about → cause

[訳例4]

Who's to Blame for the Tire Blowout: User or Maker?

When a large truck was cruising at high speed on a highway, its right-front tire suddenly blew out. (1) In consequence, the truck lost control, veered to the right, and crashed against the raised median strip to end up totaled. Reporting after its own investigation, the tire maker cited insufficient tire pressure to account for the accident. But the tire was damaged in a way very different from how a tire would usually burst.

  1. As a result

[訳例5]

Tire blowouts: who’s to blame, (1) user or workmanship?

Another tire-related car accident occurred on an expressway. The right front tire of a (2) fast moving large truck suddenly burst. The vehicle suddenly went out of control to the right and (3) badly crashed into the center divider. The cause of the accident, according to the investigation conducted by the tire manufacturer, was underinflation of the tire. The way the tire burst (4) however (5) tells that it was not a simple blowout.

  1. user を driver に変更。
  2. Wendy さんにはチェックされていないが、セッション中のコメントから、fast moving は不要と思われる。（高速道路という言葉があれば、「走行している」ことは暗に示されている。）
  3. badlyを削除し、center dividerの後に続けて、",completely totaled" を追加する。
  4. however の両側にカンマを追加（, however,）。
  5. tells を shows に変更。

○ 使い方
In Americans' perspective, 'driver' is a bit more natural than "user."

乗用車と違って、一般的に大型トラックのユーザーといえば運送会社。 過積載はそこの社長の方針、空気圧不足はそこの整備士の責任という こともあり、運転手だけに責任があるとは考えない。わが国のカルチャー、 もしくは実情ではそのほうが自然。

○ 大型トラック
large truck (ex. 16-wheeler)
small (passenger) car

○ バースト（破裂）
 burst、blowout (not very formal)、rupture

○ 中央分離帯
median (strip) といえば raised がほぼ常識。ましてやそこに ぶつかったというのだからなおさらのこと。線が引いてあるだけなら dividing line。

○ 通常のバースト
 「通常の事故」などはあり得ないので、逐語訳は無理。構文を工夫すれば usually がなんとか使える。むしろ「単純な事故」程度にとどめて、 was too severe to have been caused by a simple blowout という具合に書く。

[テキスト2]

このタイヤは，事故が起きる19日前に交換したばかりである。 トレッド溝も17.2mm残っており，走行に支障を来すような磨耗レベル では全くない。

このタイヤのメーカーが，事故タイヤを検証した結果を報告しているが， それによると「トレッド面のゴムとその下のスチールベルトの間で 生じたはく離が，タイヤのオーバーヒートによって進行し， タイヤ全周に達した時点でバーストに至った」ということである。 オーバーヒートの原因については「速度の出し過ぎか過積載， タイヤ空気圧不足のいずれか。特定は難しいが，タイヤの空気圧不足 の可能性が最も高い」とし，「製造上の不具合はなかった」という 結論を下している。

[訳例1]

The tire in question had just been replaced some 19 days prior to the accident. The tread depth was 17.2 mm, a level of wear nowhere near that which would impede operation.

The tire's manufacturer has released its findings of the investigation on the tire that caused the accident. In this report, the manufacturer stated that "The tread surface rubber and the steel belt underneath separated. Overheating caused the tire separation to spread. When the separation spread to the entire circumference of the tire, the blowout occurred." As to the cause of the overheating, the manufacturer chalks up blame to: "either excessive speed, overloading of the truck, or insufficient air pressure in the tire. Although it is difficult to establish which, insufficient air pressure is the most likely cause." The company reached the conclusion that: "this was not a result of a defective manufacture."

[訳例2]

The accident occurred only 19 days after the tire (1) was replaced. The depth of the tread grooves was 17.2 mm, which is (2) far from the level that disturbs safety driving.

The investigation report on the tire, made by the tire manufacturer, stated (3) as follows: "A (4) detachment caused between the rubber on the tread surface and the steel belt beneath the tread extended due to (5) an excessive heat of the tire. (6) At the time when the detachment reached all around the tire, the tire blew out. "The report commented that the cause of the excessive heat could be "(7) overspeed of the truck, (8) overload on the truck, or insufficient air pressure (9) in the tire. It is difficult to specify which one is the cause; however, the most probable cause is insufficient air pressure in the tire." The manufacturer concluded that "no manufacturing defect was found."

  1. was → had been（過去の事故の前ことだから過去完了）
  2. far from the level that disturbs safety driving → not thin enough to inhibit safe driving.
  3. as follows → that
  4. detachment caused → separation
  5. an excessive heat of the tire → overheatのみでよい。
  6. At the time when → When
  7. overspeed of the truck → excessive speed
  8. overload on the truck → overloading
  9. in the tire 削除。

[訳例3]

The tire (1) had been mounted on the wheel only 19 days before the accident. (2) The tread was left 17.2 mm deep and was not so (3) much worn (4) out as to hamper safe and smooth driving.

The manufacturer's report after their inspection states: (5) Part of the rubber tread surface happened to detach from the underlying steel belt, and the tire’s (6) rt. The tire blew out when the entire rubber surface separated from the steel belt. The manufacturer also notes: Either (8) over-speed, (9) overload, or insufficient air pressure in the tire (10) should be the cause. Insufficient air pressure is the most probable cause (11) though it's hard to identify. The manufacturer denied any defect (12) in manufacturing.

  1. had been mounted ← GOOD!
  2. The tread was left 17.2 mm deep and → The 17.2 mm of tread remained
  3. much 削除。
  4. out削除。
  5. Part of から the steel beltを引用符（””） でくくった方がよい。同様に、Either から to identify. までも引用符でくくる。
  6. overheat → overheating
  7. enlarged the detached part → increased the separation
  8. over-speed → excessive speed
  9. overload → overloading
  10. should → could
  11. ここにコンマを入れる。
  12. in → from

[訳例4]

In fact, the tire in question had been mounted (1) anew just nineteen days before the accident. The tread grooves were 17.2 mm deep, enough to ensure the safety of vehicle operation.

The tire maker produced a report after examining the burst tire. According to the report, (1) a separation occurred between the tread rubber and the underlying steel belt. The tread separation was then (2) promoted by high temperature until running all around the tire to finally cause the blowout. (3) The report admitted the investigation failed to conclusively determine the cause of (4) overheat, (5) whether the driver's (6) overspeeding, the truck's overloading or the tire's (7) underinflation. However, it cited underinflation as the most likely cause, and maintained that there had been no fault in the manufacture of the tire.

  1. 削除。
  2. spread by overheating until it spread
  3. Although
  4. overheating
  5. it was said to be due (to)
  6. excessive speeding
  7. poor air pressure

[訳例5]

The tire in question was virtually brand (1) new with only 19-day actual use. The tire actually (2) has 17.2 mm of tread (3) groove depth remaining, (4) which is deep enough to ensure normal driving. According to the accident report prepared by the tire manufacturer, (5) "The rubber of the tread inner surface (6) came off the underlying steel belt, and the tread-belt separation developed along the wheel (7) by an extra heat build-up in the tire, then finally caused the blowout when the whole tread surface came off." The report also says that (8) the extra heat was probably generated, (9) although it is difficult to nail down the cause, either by excessive speed, excessive load, or most likely (10) underinflation of the tire, (11) and extracts a conclusion that there were no manufacturing defects. (12)

  1. new の後にカンマを追加し、かつ with only 19 days in actual use とする。
  2. Wendy さんにはチェックされていないが、 セッション中のコメントから、has は had に訂正し、 パラグラフ内で時制を一致させる
  3. groove を削除。
  4. which is を削除。
  5. 引用符の前はカンマではなく、コロン（:）にする。
  6. came off を separated from に変更。
  7. by an extra heat build-up を owing to overheating に変更。
  8. the extra heatをoverheatingに変更。
  9. この節全体を most likely underinflation of the tire の後に移動。
    Wendy さんにはチェックされていないが、 セッション中のコメントから、is は was に訂正し、 パラグラフ内で時制を一致させる。
  10. Wendyさんにはチェックされていないが、 セッション中のコメントから、underinflation はあまり好ましくないようだ （ただし、タイヤの事故関連のサイトでは結構使われている）。
  11. ここは文章を一度切って、The report concludes that… と再開する。
    Wendy さんにはチェックされていないが、 セッション中のコメントから、concludes は concluded に訂正し、 パラグラフ内で時制を一致させる。
  12. According to the accident report 以下の文章をもっと 簡単にするように。
    訳者注：文章の構成はそれほど複雑になって いないように思うが、
    1. 文章自体が長すぎる、
    2. underinflation、heat build-up などの単語をもっと平易に、 という意味かと思われる。

○ はく離
separate (separation)、peel (peeling)、detach、exfoliate (exfoliation)

○ 不具合
defect、failure、fault、glitch…
このような用語を企業が公開する文書などで使う場合、たとえば PL 法における定義を参照、吟味の上で慎重を期す。

○ 時制
少なくとも同一パラグラフ内では consistent でなければならない。 事故の話は明らかに過去。

[テキスト3]

タイヤのゴム部分は，接地面のトレッドとサイドウオール， それらの境目であるショルダに分けて考えることができる。 トレッドは路面から大きな反力を受けるので，トレッド踏面の 裏側にはスチールベルトを数層積み重ねて剛性を高めている。 これは，サイドウオールは緩衝のためにしなやかさを要するが， 路面を踏むトレッド面は路面の突起でも容易には裂けない頑丈さ が必要だからである。

[訳例1]

The rubber portion of a tire can be divided into three parts: the tread, or the surface which makes contact with the road, the sidewall, and the shoulder between the sidewalls and the tread. The tread receives a large reactive force from the road surface, so it is reinforced by incorporating layered steel belts to the inner side of the tread. This is because while sidewalls require flexibility to absorb shock, the road-facing tread must be strong enough to withstand rupture caused by sudden bumps in the road.

[訳例2]

The rubber part of a tire (1) is mainly composed of three components: a tread that (2) contacts the road, sidewalls, and shoulders between the tread and the sidewalls. The tread is subjected to a strong counter force from the road, therefore steel belts (3) are piled on the backside of the tread so that the tread (4) has high stiffness. While sidewalls need to be flexible to (5) absorb shock from the road, (6) the tread that directly contacts the road needs to be durable enough not to easily crack over sharp bumps (7) on the road.

  1. is mainly composed of → has
  2. contacts → makes contact with
  3. are piled on → incorporated（シンプルに）
  4. has high stiffness → is more rigid
  5. absorb shock from the road ←good
  6. the tread that directly contacts → the tread directly contacting
  7. on the road 削除。

[訳例3]

The rubber section of a tire can be roughly divided into three subsections: (2) 'tread' that touches (1) with the ground, '(2) 'sidewall', and (2) 'shoulder' that (3) lies between them. Because the tread sustains an intensive reaction force from the ground, layers of steel belts are placed (4) beneath the tread to reinforce it. The tread needs enough rigidity to withstand rugged roads, while the sidewall needs to be flexible to absorb shock.

  1. with 削除。
  2. the挿入。
  3. lies → borders
  4. beneath the tread to reinforce it ← good!

[訳例4]

For the purpose of discussion, the rubber face of a tire can be divided into the tread that (1) contacts the road surface, the sidewalls, and the shoulders where the tread meets either sidewall. Since the tread (2) footprint constantly receives strong (3) reactions from hard surfaces of the roadway, it is reinforced by layers of steel belts bonded on the inside for added stiffness. While the sidewalls provide flexibility to absorb impacts from the road surface, the tread must be highly resistant to possible (4) cut damages when encountering sharp bumps on the road.

  1. makes contact with
  2. which meets the road
  3. opposing force?
  4. damage

[訳例5]

The rubber portion of a tire basically consists of tread (ground contact area), sidewalls and shoulders (connecting the tread to the sidewalls). Since the tread is subject to a significant reaction force from the ground, its inner side is reinforced with multi-layered steel belts. The tread surface should be rigid enough not to (1) break against road surface irregularities, while the sidewalls require flexibility for shock (2) absorbing purposes.

  1. break は rupture に変更。
  2. absorbing purposesをabsorptionに変更。

[テキスト4]

バーストしたタイヤを外周方向から見ると，左右のショルダに最も近いトレッド帯を1列だけ残して，トレッド面の中央部が最も外側のベルトと一緒に，ほぼ全周にわたってはがれている。そして，一部分はベルトにとどまらずその内側のカーカスも含めて半径方向にも壊滅的に断裂している。

[訳例1]

When the ruptured tire is (1) viewed from above, only the tread grooves closest to the left and right shoulders remain. The center treads, along with the outermost belt layer, have peeled off for almost the entire circumference of the tire. In addition, in some areas, not only the belts but also the interior tire carcass ruptured almost completely towards the tire center.

  1. 事故タイヤが立ててあればともかく、相対的な目視方向の表現としては疑問がある。

[訳例2]

(1) When viewed from above the tread surface of the tire of the accident, the center (2) part of the tread together with the outermost belt was peeled off along almost entire (3) periphery of the tire, leaving only (4) both rims of the tread. (5) In part, not only the belts but also the carcass beneath the belts were heavily fractured (6) even in the radial direction.

  1. When viewed from above ← good
  2. part of the を削除。
  3. periphery は circumference と同様、周囲「の長さ」という感じがある。
  4. both rims of the → the outermost
  5. In part → In some areas
    in part や partially だと、「全体を少しずつ‥‥」という感じに とられる恐れがある。「一部は」としたい場合は some areas などと するほうがよい。
  6. even 削除。

[訳例3]

When observed from the (1) outer edge of the burst tire, only a couple of tread rows, each closest to the either shoulder, (2) are left and the central part of the tread together with the outermost belt (3) has come off almost all around the tire. In some parts, not only the belt but also the underlying carcass are critically ruptured in a radial direction.

  1. outer edge of the burst tire → top
  2. are → were
  3. has → had

[訳例4]

A visual inspection of the outer (1) circumferential side of the burst tire shows the central tread rubber separating along with the underlying belt over almost the entire tire periphery, leaving only the tread edge adjacent to either shoulder. Some portions are actually hollowed out (2) with the belt layers and the carcass cut off in the radial direction.

  1. edge
  2. comma 挿入。

[訳例5]

Inspecting the tread of the burst tire from outside, the center part of the tread surface along with the outermost steel belt have (1) come off substantially around the entire circumference of the tire, except the outermost tread bands on both sides (the ones nearest to the shoulders). Some of the burst portion (2) has been damaged beyond the steel belts; the carcass located inside the belt was also completely (3) broken in the (4) lateral direction.

  1. come off を separated に変更。
  2. has been を was に変更。
  3. broken を ruptured に変更。
  4. Wendy さんにはチェックされていないが、 これは単純に radial のミス。

[テキスト5]

一般的に，オーバーヒートによるタイヤのバーストは，ショルダ部に起こる。ショルダ部でカーカスが円周方向に切断されるのだ。これは，ショルダ部がタイヤの中で最も応力が集中する場所であり，接地ごとの変形が大きく発熱量が多い所だからである。広い意味で「疲労破壊は切り欠き部分に集中して起こる」の原則に従うということだ。

[訳例1]

Generally speaking, tire blowouts due to overheating occur in the shoulder, with the shoulder area carcass being severed around the circumference of the tire. This is because the shoulder received the highest concentration of stress, being subjected to the most changes in tire shape and excessive heat. In general, this follows the principle that 'fatigue failures occur most often in cutout areas (i.e. in the grooved areas of outward facing treads).'

[訳例2]

In general, the tire blowout due to (1) an excessive heat occurs at the shoulder portion. At the shoulder (2) portion, the carcass (3) is split in the (4) circumferential direction. This is because the shoulder portion is the portion (5) where; stress concentrates most among other part of a tire, and deformations at every contact with the road are big, and heat generation is high. (6) These are generally based on the principle that most fatigue failures occur at notched portions.

  1. an excessive heat → overheating
  2. portion 削除。
  3. is split → splits
  4. circumferential direction → around the tire
  5. セミコロン（;）削除。
  6. These are → This is

[訳例3]

Generally, (1) overheat causes a tire to blow out in the shoulder. The carcass beneath the shoulder section (2) gets ruptured (3) in a radial direction. This is because the shoulder section suffers more stress than any other part, more distortion and heat generation caused by (4) every touch to the ground. The principle '(5) a fatigue failure centers around notches' roughly applies.

  1. overheat → overheating
  2. gets → is
  3. in a radial direction→ radially
  4. every touch to → each contact with
  5. a fatigue failure centers → fatigue failures center

[訳例4]

In the event of tire explosion due to (1) overheat, the shoulder is typically the first to burst, where the carcass starts to break in the circumferential direction. Receiving much more stress than any other parts of the tire, the shoulder severely (2) flexes and heats up as the vehicle hits the road. There is an empirical law that cutout portions are most susceptible to fatigue failure. In a broad sense, the same rule should hold true in the case of tire blowouts as well.

  1. overheating
  2. distorts

[訳例5]

In general, the most vulnerable part of a tire for heat-induced tire burst is the shoulders and the carcass at the shoulder is broken in the circumferential direction. This is because the shoulder is where the greatest stress concentration is observed in a tire and where the greatest heat is generated due to large deformation on every contact with the ground. (1) One of the mechanical principles applies here: In a broad sense, fatigue breakdown occurs predominantly at notches.

  1. one of the mechanical principles を one mechanical principle に変更。

○ 一部（断裂）
some parts、in some sections など（partially はNG）。

○ 円周方向に（切断）
all around the wheel
around the edge of the tire

○ 全周にわたって、外周方向から見ると、半径方向にも
circumference は、一般的には外周（円周）の長さ。
periphery は周辺、外縁。
「全周」は、長さ（距離）だから circumference でよい。
「外周方向から見る」は、単に Looking at the tread.. でよい。
「半径方向」は radial direction だが、平たく言えば toward (towards) the center of the tire。
厳密に記述する必要があれば、特許明細の翻訳などでは図が用いられる。

○ Some Asides
J to E translation of patent specs is an example of bread 'n' butter work. For this, literary interpretation will do.
No one will ever pay for poetry and other spiritual ones. <g>

○ 参考サイト
Tread and Belt Separations

投稿者 kz : 2005年01月22日 22:54

トラックバック

このエントリーのトラックバックURL:

コメント

コメントしてください




保存しますか?