JPS586108B2 - Thick-walled metal tubing for high-pressure fluid supply - Google Patents

Description

【発明の詳細な説明】 本発明は例えばディーゼル内燃機関の燃料噴射管のよう
に、高圧流体の供給用に配管多用される厚肉金属管の管
材に関し、特にその孔内周壁面の表面状態の改善に関す
る。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a pipe material for a thick-walled metal pipe that is often used for supplying high-pressure fluid, such as a fuel injection pipe for a diesel internal combustion engine, and particularly relates to a pipe material for a thick-walled metal pipe that is often used for supplying high-pressure fluid, such as a fuel injection pipe for a diesel internal combustion engine. Regarding improvement.

最近、自動車等の内燃機関においては、燃焼効率の向上
に伴う機関の馬力アンプ等に関連して燃料の噴射圧を高
める傾向にある。Recently, in internal combustion engines such as automobiles, there has been a trend to increase the fuel injection pressure in conjunction with engine horsepower amplifiers and the like to improve combustion efficiency.

しかしながら、これら内燃機関に使用される従来の燃料
噴射管管材は、高圧配管用炭素鋼鋼管からなる素材管に
焼鈍処理と伸管処理を繰返すことにより、孔内周壁面を
単に真円状に仕上げた所望寸法の管材に成形していだに
すぎず、従って、第３図に示すように、伸管処理の繰返
しによって、管材１１の孔内周壁面に鋭角状の掻き傷、
あるいはヘアークラツク１３の残存がさけられなかった
。However, conventional fuel injection pipe materials used in these internal combustion engines simply finish the inner circumferential wall of the hole into a perfect circle by repeatedly annealing and elongating the material pipe made of carbon steel pipe for high-pressure piping. Therefore, as shown in FIG. 3, due to the repeated tube drawing process, acute-angled scratches and
Alternatively, the remaining hair cracks 13 could not be avoided.

このため、かかる従来の管材を燃料噴射圧の高い最近の
内燃機関の燃料噴射管として使用したときには、極めて
高い流圧と絶えず繰り返される流圧変動によって生ずる
キャビテーション（ｃａｖｉｔａｔｉｏｎ）に伴って、
前記鋭角状の掻き傷、ヘアークラックの部分に局部的な
壊食（ｅｒｏｓｉｏｎ）を促進させるとともに、機関の
振動によって生ずる材料の疲労と相俟って壊食の進んだ
前記掻き傷あるいはへアークラック部分にしばしば亀裂
、折損を誘発するという問題があった。For this reason, when such conventional pipe materials are used as fuel injection pipes in modern internal combustion engines with high fuel injection pressures, cavitation occurs due to extremely high fluid pressure and constantly repeated fluid pressure fluctuations.
Localized erosion is promoted in the area of the sharp-angled scratch or hair crack, and the scratch or hair crack has progressed in erosion due to fatigue of the material caused by vibration of the engine. There was a problem that parts often cracked and broke.

従って、本発明の目的は管材の孔内周壁面を鋭角状凹凸
部のない梨地肌に形成することによってかかる問題を効
果的に解決し、長期使用に耐え得る高圧流体供給用厚肉
金属管材を提供することにある。Therefore, an object of the present invention is to effectively solve this problem by forming the inner circumferential wall surface of the hole of the tube material to have a satin finish without sharp unevenness, and to provide a thick-walled metal tube material for high-pressure fluid supply that can withstand long-term use. It is about providing.

以下、図面について詳述すれば、１は例えば高圧配管用
炭素鋼鋼管等を素管材として、その後の焼鈍処理と伸管
処理の繰返し作業により、所望の寸法に構成してなる厚
肉金属管であり、該金属管は第２図に示すように、最終
の伸管処理の後にその孔内周壁面２にサンドブラスト法
、ショットピーニング法、あるいは化学処理等の表面処
理を施すことにより、該孔内周壁面２を鋭角形状部分の
とれた梨地肌３に構成してなるものである。In the following, referring to the drawings in detail, 1 is a thick-walled metal tube made of a carbon steel tube for high-pressure piping, etc. as a blank tube material, and then constructed into desired dimensions by repeated annealing and tube drawing operations. As shown in Fig. 2, the metal tube is made by applying a surface treatment such as sandblasting, shot peening, or chemical treatment to the inner circumferential wall surface 2 of the hole after the final tube elongation process. The peripheral wall surface 2 is configured to have a matte texture 3 with an acute-angled portion.

このように、本発明の金属管はその内周壁面を上記のよ
うに梨地肌に表面加工することにより、伸管の最終状態
において内周壁面に残存していた掻き傷あるいはへアー
クラックによる鋭角形状部分は丸みを帯びたなだらかな
表面状態に形成してなるため、キャビテーションに伴う
壊食の主因をなすと考えられている気泡（ｃａｖｉｔｙ
）の発生が全体的に減少するとともに、気泡の発生自体
も孔内周壁面に一様に分散され、局部に集中発生するこ
とがなくなる。In this way, the metal tube of the present invention has its inner circumferential wall surface treated to have a satin finish as described above, thereby eliminating sharp angles caused by scratches or hair cracks remaining on the inner circumferential wall surface in the final state of pipe drawing. The shaped part has a rounded and smooth surface, so it is free from air bubbles, which are thought to be the main cause of erosion caused by cavitation.
) The generation of bubbles is reduced overall, and the bubbles themselves are evenly distributed on the inner peripheral wall surface of the hole, and are no longer concentrated in localized areas.

従って、本発明によればこれら気泡の崩壊によって惹起
される孔内周壁面での局部壊食を減少して機関に及ぼす
悪影響を阻止し得ることは勿論、壊食の成長に伴って生
ずる管の亀裂、折損事故が効果的に防止されるので長期
使用に耐え得る高圧流体供給用厚肉金属管を得ることが
でき、極めて有用である。Therefore, according to the present invention, it is possible to reduce the local erosion on the inner circumferential wall surface of the hole caused by the collapse of these bubbles, and prevent the adverse effects on the engine. Since cracks and breakage accidents are effectively prevented, a thick-walled metal pipe for supplying high-pressure fluid that can withstand long-term use can be obtained, which is extremely useful.

【図面の簡単な説明】[Brief explanation of drawings]

第１図は本発明の一実施例に係る高圧流体供給用厚肉金
属管材の平面図、第２図は第１図Ａ−Ａ線部分拡大断面
図、第３図は従来の高圧流体供給用厚肉金属管材の部分
拡大断面図である。 １・・・金属管、２・・・孔内周壁面、３・・・梨地肌
。FIG. 1 is a plan view of a thick-walled metal pipe material for high-pressure fluid supply according to an embodiment of the present invention, FIG. 2 is a partially enlarged cross-sectional view taken along line A-A in FIG. 1, and FIG. 3 is a conventional high-pressure fluid supply pipe. FIG. 3 is a partially enlarged cross-sectional view of a thick-walled metal tube. 1... Metal tube, 2... Hole inner circumferential wall surface, 3... Satin skin.

Claims (1)

【特許請求の範囲】[Claims] １ 金属管１の孔内周壁面２を梨地肌３に構成してなる
ことを特徴とする高圧流体供給用厚肉金属管材。1. A thick-walled metal pipe material for supplying high-pressure fluid, characterized in that the inner peripheral wall surface 2 of the hole of the metal pipe 1 is configured with a matte texture 3.