JP2920316B2 - Manufacturing method of circular pipe with flat part - Google Patents
Manufacturing method of circular pipe with flat partInfo
- Publication number
- JP2920316B2 JP2920316B2 JP15463990A JP15463990A JP2920316B2 JP 2920316 B2 JP2920316 B2 JP 2920316B2 JP 15463990 A JP15463990 A JP 15463990A JP 15463990 A JP15463990 A JP 15463990A JP 2920316 B2 JP2920316 B2 JP 2920316B2
- Authority
- JP
- Japan
- Prior art keywords
- hole
- processing tool
- circular tube
- circular
- processing
- 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.)
- Expired - Fee Related
Links
Landscapes
- Shaping Of Tube Ends By Bending Or Straightening (AREA)
- Gears, Cams (AREA)
Description
【発明の詳細な説明】 産業上の利用分野 この発明は、長さの中間部において周壁に平坦部が形
成されている平坦部付き円管を製造する方法に関する。Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a circular tube with a flat portion having a flat portion formed on a peripheral wall at an intermediate portion of a length.
この明細書において、第２図および第３図の上下を上
下というものとする。また、第２図の左側を前、右側を
後というものとする。さらに、第３図の左側を左、右側
を右というものとする。In this specification, the upper and lower sides of FIGS. 2 and 3 are referred to as upper and lower sides. The left side of FIG. 2 is referred to as front, and the right side is referred to as rear. Further, the left side of FIG. 3 is referred to as left and the right side is referred to as right.
従来の技術と発明の課題 たとえば車両のラックピニオン式ステアリング装置の
ラック棒としては、従来、横断面円形の中実棒の周面の
一部にフライス加工を施すことによって、所定長さおよ
び幅を有する平坦部を形成し、この平坦部にブローチ加
工を施すことによって歯を形成し、さらにガンドリルを
用いて軸線方向に貫通する穴を形式して重量を軽減した
ものが用いられていた。しかしながら、このラック棒を
製造するには、ガンドリルを用いての穴あけ加工を施す
必要があって作業が面倒になるとともに、材料歩留まり
が悪いという問題があった。2. Description of the Related Art For example, as a rack bar of a rack and pinion type steering device of a vehicle, a predetermined length and width are conventionally obtained by milling a part of a peripheral surface of a solid bar having a circular cross section. There has been used a flat portion having a flat portion, broaching the flat portion to form teeth, and using a gun drill to form a hole penetrating in the axial direction to reduce the weight. However, in order to manufacture this rack bar, it is necessary to perform a drilling process using a gun drill, so that the operation is troublesome and there is a problem that the material yield is low.
この問題を解決するためには、円管の周壁にフライス
加工を施して平坦部を形成し、この平坦部に歯を形成す
ればよいように考えられるが、円管の周壁にフライス加
工を施すのでは、形成された平坦部の肉厚が薄くなるの
で、平坦部の肉厚を、歯を形成するために必要な所定の
肉厚とするには、他の部分の周壁の肉厚を大きくしなけ
ればならず、ラック棒の重量が大きくなるという問題が
あった。In order to solve this problem, it is considered that milling is performed on the peripheral wall of the circular tube to form a flat portion, and teeth are formed on the flat portion. However, milling is performed on the peripheral wall of the circular tube. In this case, the thickness of the formed flat portion is reduced. Therefore, in order to make the thickness of the flat portion a predetermined thickness necessary for forming the teeth, the thickness of the peripheral wall of the other portion is increased. Therefore, there is a problem that the weight of the rack bar increases.
そこで、この問題を解決するために、金型で円管を保
持し、下面が形成すべき平坦部と等しい大きさの長方形
状平坦加工面となされた成形パンチで円管の周壁を外側
から押圧することにより平坦部を形成する方法を採用す
ることが考えられた、しかしながら、この方法では、形
成された平坦部の軸線方向および円周方向の両側で円管
の外径が変形したり、平坦部の中央部が凹んだりすると
いう問題があった。また、平坦部の周囲に上方に突出し
た大きなばりが生じるという問題があった。さらに、平
坦部の長さを変更するためには、種々のサイズの金型お
よびパンチを用意する必要があり、コストが高くなると
いう問題があった。しかも、成形パンチで１度に平坦部
全体を成形するため、成形パンチに大きな荷重を掛ける
必要があり、能力の大きいプレス機械を用いなければな
らないという問題があった。Therefore, in order to solve this problem, the circular tube is held by a mold, and the peripheral wall of the circular tube is pressed from the outside with a forming punch having a rectangular flat processing surface having the same size as the flat portion whose lower surface is to be formed. However, in this method, the outer diameter of the circular pipe is deformed or flattened on both sides in the axial direction and the circumferential direction of the formed flat portion. There was a problem that the central part of the part was dented. Further, there is a problem that a large burr protruding upward is generated around the flat portion. Further, in order to change the length of the flat portion, it is necessary to prepare dies and punches of various sizes, and there is a problem that the cost is increased. Moreover, since the entire flat portion is formed at a time by the forming punch, a large load must be applied to the forming punch, and there is a problem that a press machine having a large capacity must be used.
これらの問題を解決するために、本出願人は、先に、
周面に外方に突出した円筒状加工面を有する棒状加工具
と、円管を軸線方向に移動自在に挿入しうる円管挿入用
貫通穴、および上方から見て円管挿入用貫通穴と直交す
るとともに、円管挿入用貫通穴の軸線方向から見て一部
分が重複し、かつ加工具を、その加工面が円管挿入用貫
通穴内に臨むように挿入しうる加工具挿入用貫通穴を有
する金型とよりなる装置を使用し、円管を円管挿入用貫
通穴内に挿入し、加工具をその周面の横断面凸円弧状加
工面が円管側を向くように加工具挿入用貫通穴内に差込
むことによって、円管の周壁の一部が塑性変形するよう
に棒状加工具の加工面を周壁に押し付け、この状態で円
管と加工具とを円管の軸線方向に相対的に移動して平坦
部を形成することを特徴とする方法を提案した（特願平
１−167427号）。しかしながら、この方法では、円管挿
入用貫通穴の軸線と直交する断面において、金型の円管
挿入用貫通穴の周面と加工具挿入用貫通穴の周面とが鋭
角をなすので、この鋭角部分の強度が小さくなり、加工
具の加工面を円管周壁に押し付けたさい、および円管と
加工具とを円管の軸線方向に相対的に移動させたさいに
破損し易いという問題がある。To solve these problems, Applicant firstly
A rod-shaped processing tool having a cylindrical processing surface protruding outward on a peripheral surface, a circular tube insertion through hole capable of inserting a circular tube movably in an axial direction, and a circular tube insertion through hole as viewed from above; At right angles, there is a through hole for processing tool insertion, which can be inserted so that the processing tool faces the inside of the through hole for circular tube insertion, and a part of which overlaps when viewed from the axial direction of the through hole for circular tube insertion. Insert the circular tube into the circular tube insertion through hole using a device consisting of a mold that has a die, and insert the processing tool so that the cross-section convex arc-shaped processing surface of the peripheral surface faces the circular tube side. By inserting it into the through hole, the processing surface of the rod-shaped processing tool is pressed against the peripheral wall so that a part of the peripheral wall of the circular pipe is plastically deformed, and in this state, the circular pipe and the processing tool are relatively moved in the axial direction of the circular pipe. (Japanese Patent Application No. 1-167427). However, in this method, in a cross section orthogonal to the axis of the through hole for inserting a circular tube, the peripheral surface of the through hole for inserting a circular tube of the mold and the peripheral surface of the through hole for inserting a processing tool form an acute angle. The strength of the acute angle portion is reduced, and the problem that the processing surface of the processing tool is pressed against the circumferential wall of the circular pipe and that the circular pipe and the processing tool are easily broken when moved relatively in the axial direction of the circular pipe. is there.
この発明の目的は、上記問題を全て解決した平坦部付
き円管の製造方法を提供することにある。An object of the present invention is to provide a method for manufacturing a circular tube with a flat portion that solves all of the above problems.
課題を解決するための手段 この発明による平坦部付き円管の製造方法は上下方向
に伸びるとともに下端に加工面が形成されており、か
つ、この加工面の最下位部分に、前後から見て円管の周
壁の外径よりも小さい所定長さを有する直線状部分が設
けられている棒状加工具と、前後方向に伸びるとともに
円管を軸線方向に移動自在に挿入しうる円管挿入用貫通
穴、および上下方向に伸びるとともに下端が円管挿入用
貫通穴の内周面に開口し、かつ加工具をその軸線方向に
移動自在に挿入しうる加工具挿入用貫通穴を備えている
金型とよりなり、加工具挿入用貫通穴の下端開口の左右
方向の幅が、棒状加工具下端の加工面における直線状部
分の長さと等しくなされている装置を使用し、円管を円
管挿入用貫通穴内に挿入した後、加工具を加工具挿入用
貫通穴内に挿入するとともに、円管の周壁の一部が塑性
変形するように加工面を周壁に押し付け、ついで円管を
その軸線方向に移動させることにより平坦部を形成する
ことを特徴とするものである。Means for Solving the Problems In the method for manufacturing a circular tube with a flat portion according to the present invention, a processing surface is formed at the lower end while extending in the up-down direction, and a lowermost portion of the processing surface has a circular shape when viewed from front and rear. A rod-shaped processing tool provided with a linear portion having a predetermined length smaller than the outer diameter of the peripheral wall of the pipe, and a through-hole for inserting a circular pipe extending in the front-rear direction and capable of inserting the circular pipe movably in the axial direction. A mold having a processing tool insertion through-hole extending vertically and having a lower end opened on the inner peripheral surface of the circular tube insertion through-hole and capable of inserting the processing tool movably in the axial direction. Using a device in which the width in the left-right direction of the lower end opening of the through hole for processing tool insertion is made equal to the length of the linear portion on the processing surface of the lower end of the rod-shaped processing tool, penetrate the circular pipe through the After inserting the tool into the hole, insert the tool Inserting into the required through hole, pressing the working surface against the peripheral wall so that a part of the peripheral wall of the circular tube is plastically deformed, and then moving the circular tube in the axial direction to form a flat part. Is what you do.
作用 この発明の方法によれば、使用する装置の加工具の下
端に加工面が形成され、加工面の最下位部分に、前後か
ら見て円管の周壁の外径よりも小さい所定長さを有する
直線状部分が設けられており、金型が、前後方向に伸び
るとともに円管を軸線方向に移動自在に挿入しうる円管
挿入用貫通穴、および上下方向に伸びるとともに下端が
円管挿入用貫通穴の内周面に開口し、かつ加工具をその
軸線方向に移動自在に挿入しうる加工具挿入用貫通穴を
備えているので、円管挿入用貫通穴の軸線と直交する断
面において、金型の円管挿入用貫通穴の周面と加工具挿
入用貫通穴の周面とは鈍角をなす。しかも、円管挿入用
貫通穴および加工具挿入用貫通穴の軸線を含む断面にお
いて、金型の円管挿入用貫通穴の周面と加工具挿入用貫
通穴の周面とは直角をなす。また、使用する装置の加工
挿入用貫通穴の下端開口の左右方向の幅が、棒状加工具
下端の加工面における直線状部分の長さと等しくなされ
ているので、加工時には、前後から見て、円管挿入用貫
通穴の内周面と加工具との間に隙間が生じることはな
い。さらに、円管を円管挿入用貫通穴内に挿入した後、
上下方向に伸びるとともに下端に加工面が形成されてお
り、かつの加工面の最下位部分に、前後から見て円管の
周壁の外径よりも小さい所定長さを有する直線状部分が
設けられている棒状加工具を加工具挿入用貫通穴内に挿
入するとともに、円管の周壁の一部が塑性変形するよう
に加工面を周壁に押し付け、ついで円管をその軸線方向
に移動させることにより平坦部を形成するので、加工具
を円管の周壁に押し付ける力が比較的小さくてすむ。According to the method of the present invention, a processing surface is formed at the lower end of the processing tool of the device to be used, and a predetermined length smaller than the outer diameter of the peripheral wall of the circular pipe as viewed from the front and rear is formed at the lowermost part of the processing surface. The mold has a straight part, and the mold extends in the front-back direction and a circular tube insertion through hole that allows the circular tube to be inserted movably in the axial direction. Opened on the inner peripheral surface of the through hole, and provided with a through hole for processing tool insertion that can insert the processing tool movably in the axial direction, in a cross section orthogonal to the axis of the through hole for circular pipe insertion, The peripheral surface of the through hole for inserting the circular tube of the mold and the peripheral surface of the through hole for inserting the processing tool form an obtuse angle. In addition, in the cross section including the axis of the through hole for inserting the circular tube and the through hole for inserting the processing tool, the peripheral surface of the through hole for inserting the circular tube of the mold and the peripheral surface of the through hole for inserting the processing tool are at right angles. Further, since the width in the left-right direction of the lower end opening of the through hole for processing insertion of the device to be used is equal to the length of a linear portion on the processing surface of the lower end of the rod-shaped processing tool, when processing, when viewed from the front and back, a circle There is no gap between the inner peripheral surface of the tube insertion through hole and the processing tool. Furthermore, after inserting the circular tube into the circular tube insertion through hole,
A processing surface is formed at the lower end while extending in the vertical direction, and a linear portion having a predetermined length smaller than the outer diameter of the peripheral wall of the circular tube when viewed from the front and rear is provided at the lowest part of the processing surface. Insert the rod-shaped processing tool into the through hole for processing tool insertion, press the processing surface against the peripheral wall so that a part of the peripheral wall of the circular tube is plastically deformed, and then move the circular tube in the axial direction to make it flat. Since the portion is formed, the force for pressing the processing tool against the peripheral wall of the circular tube can be relatively small.
実 施 例 以下、図面を参照してこの発明の１実施例を説明す
る。Embodiment An embodiment of the present invention will be described below with reference to the drawings.
第７図は、この発明の方法によって製造された平坦部
付き円管（１）を示す。この円管（１）の周壁（1a）外
周面の上部における長さの中間部には、周壁（1a）外周
面の横断面における１つの弦の長さと等しい幅を有する
平坦部（２）が所定長さにわたって形成されている。そ
して、この円管（１）の平坦部（２）に歯（３）を形成
することにより、たとえば第８図に示すようなラック棒
（４）がつくられる。FIG. 7 shows a flat tube (1) manufactured by the method of the present invention. A flat portion (2) having a width equal to the length of one chord in a cross section of the outer peripheral surface of the peripheral wall (1a) is provided at an intermediate portion of the upper portion of the outer peripheral surface of the peripheral wall (1a) of the circular pipe (1). It is formed over a predetermined length. Then, by forming teeth (3) on the flat portion (2) of the circular tube (1), a rack bar (4) as shown in FIG. 8, for example, is produced.
第１図〜第３図はこの発明の方法の実施に用いられる
平坦部付き円管の製造装置を示す。1 to 3 show an apparatus for manufacturing a circular tube with a flat portion used for carrying out the method of the present invention.
第１図〜第３図において、平坦部付き円管（１）の製
造装置は、横断面円形の棒状加工具（10）と、上面がカ
バー（21）で覆われた金型（20）とを備えている。加工
具（10）の下端面には、左右から見て前後の中央部が下
方に突出した凸円弧状である加工面（11）が形成されて
いる。加工面（11）の下縁（11a）は、前後から見て円
管（１）の平坦部（２）の幅と等しい長さを有する直線
状となされている。加工具（10）の上端には上方から見
て前後に長い略長方形の板状頭部（12）が一体に形成さ
れている。頭部（12）の上面は、前後から見て左右の中
央部が上方に突出した円筒面（12a）となされている。1 to 3, a manufacturing apparatus for a circular tube with a flat portion (1) includes a rod-shaped processing tool (10) having a circular cross section and a mold (20) whose upper surface is covered with a cover (21). It has. On the lower end surface of the processing tool (10), a processing surface (11) having a convex arc shape whose central part in the front and rear as viewed from the left and right protrudes downward is formed. The lower edge (11a) of the processing surface (11) has a linear shape having a length equal to the width of the flat portion (2) of the circular pipe (1) when viewed from front and rear. At the upper end of the processing tool (10), a substantially rectangular plate-shaped head (12) that is long from front to back when viewed from above is integrally formed. The upper surface of the head (12) is formed as a cylindrical surface (12a) whose left and right central portions project upward when viewed from the front and rear.
金型（20）上面の前後の中央部には左右にのびる角溝
（22）が形成されている。角溝（22）の底面の左右の中
央部には、上方から見て前後に長い長方形状の凹所（2
3）が形成されている。凹所（23）の大きさは、加工具
（10）の頭部（12）が嵌まるような大きさである。ま
た、凹所（23）の深さは、頭部（12）が凹所（23）内に
嵌め入れられたさいに、頭部（12）の円筒面（12a）の
頂部が角溝（22）の底面と同一高さ位置にくるような深
さとなされている。金型（20）上面における角溝（22）
の前後両側の左右両端よりの部分にはそれぞれねじ穴
（24）が形成されており、カバー（21）を貫通したおね
じ（25）がねじ穴（24）にねじ嵌められることによって
カバー（21）が金型（20）に固定されるようになってい
る。そして、角溝（22）とカバー（21）の下面により、
加工具押し下げ部材挿入穴（26）が形成されている。金
型（20）の角溝（22）よりも下方の部分には、金型（2
0）を前後に貫通した横断面円形の円管挿入用貫通穴（2
7）が形成されている。角溝（22）の凹所（23）の底面
と円管挿入用貫通穴（27）との間に、上下にのびかつ凹
所（23）の左右方向の幅よりも小さい直径を有する横断
面円形の加工具挿入用貫通穴（28）が形成されている。
両貫通穴（27）（28）の軸線は、左方から見て直交して
いる。加工具挿入用貫通穴（28）の円管挿入用貫通穴
（27）周面への下端開口の周縁は、加工具（10）の頭部
（12）を凹所（23）内に嵌め入れたさいに加工具（10）
の加工面（11）の周縁と合致するようになされており、
当然のことながら加工具挿入用貫通穴（28）の下端開口
の左右方向の幅が、棒状加工具（10）下端の加工面（1
1）における下縁（11a）の長さと等しくなされている。
したがって、円管挿入用貫通穴（27）の軸線と直交する
断面において、金型（20）の円管挿入用貫通穴（27）の
周面と加工具挿入用貫通穴（28）の周面とは鈍角をな
し、円管挿入用貫通穴（27）および加工具挿入用貫通穴
（28）の軸線を含む断面において、円管挿入用貫通穴
（27）の周面と加工具挿入用貫通穴（28）の周面とは直
角をなす。Square grooves (22) extending left and right are formed in front and rear central portions of the upper surface of the mold (20). The left and right central parts of the bottom of the square groove (22) are rectangular recesses (2
3) is formed. The size of the recess (23) is such that the head (12) of the processing tool (10) fits. The depth of the recess (23) is such that when the head (12) is fitted into the recess (23), the top of the cylindrical surface (12a) of the head (12) has a square groove (22). The depth is set so as to be at the same height as the bottom surface of (). Square groove (22) on top of mold (20)
A screw hole (24) is formed in each of the left and right ends on both front and rear sides of the cover (21). A male screw (25) penetrating the cover (21) is screwed into the screw hole (24) to cover the cover (21). ) Is fixed to the mold (20). And, by the square groove (22) and the lower surface of the cover (21),
A processing tool press-down member insertion hole (26) is formed. The part of the mold (20) below the square groove (22) is
0) through-hole for circular tube insertion (2
7) is formed. A cross section extending vertically between the bottom surface of the recess (23) of the square groove (22) and the through hole (27) for inserting a circular tube and having a diameter smaller than the width of the recess (23) in the left-right direction. A circular processing tool insertion through hole (28) is formed.
The axes of the through holes (27) and (28) are orthogonal when viewed from the left. The peripheral edge of the lower end opening of the through hole (28) for inserting the processing tool into the through hole (27) for inserting the circular tube fits the head (12) of the processing tool (10) into the recess (23). Processing tools (10)
It is made to match the peripheral edge of the processing surface (11) of
Naturally, the width in the left-right direction of the lower end opening of the through hole (28) for inserting the processing tool is equal to the processing surface (1
It is made equal to the length of the lower edge (11a) in 1).
Therefore, in a cross section orthogonal to the axis of the circular tube insertion through hole (27), the peripheral surface of the circular tube insertion through hole (27) of the mold (20) and the peripheral surface of the processing tool insertion through hole (28). Is formed at an obtuse angle, and in a section including the axis of the through hole for inserting a circular pipe (27) and the through hole for inserting a processing tool (28), the peripheral surface of the through hole for inserting a circular pipe (27) and the through hole for inserting a processing tool. Make a right angle with the peripheral surface of the hole (28).
金型（20）の加工具押し下げ部材挿入用穴（26）内に
は、横断面方形の加工具押し下げ部材（30）が摺動自在
に嵌められるようになっている。加工具押し下げ部材
（30）は、金型（20）の右方に配置された図示しない適
当な押圧装置によって左方に移動されるようになってい
る。加工具押し下げ部材（30）の下面の長さの中間部に
は、右方に向かって下方に傾斜した傾斜面（30a）が形
成されており、この部材（30）が右から左に移動したさ
いに、この傾斜面（30a）のくさび作用によって加工具
（10）が押し下げられる。A processing tool pressing member (30) having a rectangular cross section is slidably fitted in the processing tool pressing member insertion hole (26) of the mold (20). The processing tool pressing member (30) is moved to the left by a suitable pressing device (not shown) arranged to the right of the mold (20). An inclined surface (30a) inclined downward toward the right is formed in the middle of the length of the lower surface of the processing tool pressing member (30), and the member (30) has moved from right to left. At last, the processing tool (10) is pushed down by the wedge action of the inclined surface (30a).
金型（20）の後側面には、金型（20）の後方に配置さ
れかつ素材となる円管（40）および円管（40）を前方に
移動させるパンチ（32）を案内するガイド（31）が固定
されている。On the rear side of the mold (20), a guide (32) which is disposed behind the mold (20) and guides a circular pipe (40) as a material and a punch (32) for moving the circular pipe (40) forward. 31) is fixed.
上記装置を用いて平坦部付き円管（１）を製造する方
法を第４図〜第６図を参照して説明する。まず素材とな
る円管（40）を金型（20）の円管挿入用貫通穴（27）内
に挿入した後、加工具（10）を上方から加工具挿入用貫
通穴（28）に挿入し、カバー（21）を取付ける。このと
き、加工具（10）の加工面（11）の下縁（11a）が円管
（40）の周壁（40a）の外周面に当接しているととも
に、その頭部（12）の円筒面（12a）は凹所（23）から
上方に突出している。ついで、右方から押し下げ部材挿
入用穴（26）内に加工具押し下げ部材（30）を挿入し
（第４図参照）、図示しない押圧装置によってこの部材
（30）を左方に移動させる。すると、押し下げ部材（3
0）の下面の傾斜面（30a）が加工具（10）の頭部（12）
の円筒面（12a）に摺接し、傾斜面（30a）のくさび作用
によって加工具（10）が押し下げられ、加工具（10）の
加工面（11）によって円管（40）の周壁（40a）が塑性
変形させられ、円形（40）の軸線方向と直角をなす方向
にのびる凹み（41）が形成される（第５図参照）。その
後、この状態で、パンチ（32）によって円管（40）を前
方に移動させる。すると、加工具（10）の加工面（11）
により、円管（40）の移動距離に対応する長さを持った
平坦部（２）が、円管（40）の周壁（40a）に形成され
る。こうして、平坦部（２）付き円管（１）が製造され
る（第６図参照）。A method for manufacturing a circular tube with a flat portion (1) using the above apparatus will be described with reference to FIGS. First, insert the circular pipe (40), which is the material, into the through-hole (27) for inserting the circular pipe of the mold (20), and then insert the processing tool (10) from above into the through-hole (28) for inserting the processing tool. And attach the cover (21). At this time, the lower edge (11a) of the processing surface (11) of the processing tool (10) is in contact with the outer peripheral surface of the peripheral wall (40a) of the circular pipe (40) and the cylindrical surface of the head (12) thereof (12a) protrudes upward from the recess (23). Next, the working tool pressing member (30) is inserted into the pressing member insertion hole (26) from the right (see FIG. 4), and the member (30) is moved to the left by a pressing device (not shown). Then press down member (3
The inclined surface (30a) on the lower surface of (0) is the head (12) of the processing tool (10).
The processing tool (10) is pushed down by the wedge action of the inclined surface (30a), and the peripheral wall (40a) of the circular pipe (40) is processed by the processing surface (11) of the processing tool (10). Is plastically deformed to form a recess (41) extending in a direction perpendicular to the axial direction of the circle (40) (see FIG. 5). Thereafter, in this state, the circular pipe (40) is moved forward by the punch (32). Then, the processing surface (11) of the processing tool (10)
Thereby, a flat portion (2) having a length corresponding to the moving distance of the circular pipe (40) is formed on the peripheral wall (40a) of the circular pipe (40). Thus, a circular tube (1) with a flat portion (2) is manufactured (see FIG. 6).
発明の効果 この発明によれば、上述のようにして、平坦部付き円
管を製造することができるので、材料歩留まりがよくな
るとともに、作業を容易に行える。しかも、形成された
平坦部の肉厚は他の部分の周壁の肉厚とほぼ等しくなる
ので、この平坦部付き円管をラック棒に使用した場合
に、十分な歯だけを有する歯を形成することができると
ともに、重量が増加するのを防止することができる。ま
た、円管を円管挿入用貫通穴内に挿入した後、上下方向
に伸びるとともに下端に加工面が形成されており、かつ
この加工面の最下位部分に、前後から見て円管の周壁の
外径よりも小さい所定長さを有する直線状部分が設けら
れている棒状加工具を加工具挿入用貫通穴内に挿入し、
円管の周壁の一部が塑性変形するように棒状加工具の加
工面を周壁に押し付け、ついで円管をその軸線方向に移
動させることにより平坦部を形成するので、加工具を円
管の周壁に押し付ける力が比較的小さくてすむ。したが
って、能力の大きいプレス機械を必要とせず、かつ同じ
装置を用いて種々の長さの平坦部を有する平坦部付き円
管を製造することができるので、コストが安くなる。し
かも、平坦部の両側で円管の外径が変形せず、スプリン
グバックの影響を小さくできるため平坦部の製作精度が
向上する。さらに、、棒状加工具を、その軸線が円管の
軸線と直交し、かつ加工面の直線状部分が円管の軸線と
直角をなすように配置し、加工具の下端加工面を円管周
壁に押し付けて円管の周壁の一部を敬方向内方に塑性変
形させるので、金型が破損するおそれはない。According to the present invention, a circular tube with a flat portion can be manufactured as described above, so that the material yield is improved and the work can be easily performed. In addition, since the thickness of the formed flat portion is substantially equal to the thickness of the peripheral wall of the other portion, when this circular tube with the flat portion is used for a rack bar, teeth having only enough teeth are formed. And increase in weight can be prevented. After the circular pipe is inserted into the through hole for inserting a circular pipe, a processing surface is formed at the lower end while extending in the vertical direction, and a lowermost portion of the processing surface has a peripheral wall of the circular pipe when viewed from front and rear. Insert the rod-shaped processing tool provided with a linear portion having a predetermined length smaller than the outer diameter into the processing tool insertion through-hole,
The processing surface of the rod-shaped processing tool is pressed against the peripheral wall so that a part of the peripheral wall of the circular pipe is plastically deformed, and then the circular pipe is moved in the axial direction to form a flat portion. The pressing force on the surface can be relatively small. Therefore, flat tubes having various lengths of flat portions can be manufactured using the same apparatus without using a press machine having a large capacity, and the cost is reduced. In addition, since the outer diameter of the circular tube is not deformed on both sides of the flat portion and the influence of springback can be reduced, the manufacturing accuracy of the flat portion is improved. Further, the rod-shaped processing tool is arranged so that its axis is orthogonal to the axis of the circular pipe, and the linear portion of the processing surface is perpendicular to the axis of the circular pipe, and the processing surface at the lower end of the processing tool is a circular pipe peripheral wall. , And a part of the peripheral wall of the circular pipe is plastically deformed inward in the oblique direction, so that there is no possibility that the mold is damaged.
また、この発明によれば、上述のように、円管挿入用
貫通穴の軸線と直交する断面において、金型の円管挿入
用貫通穴の周面と加工具挿入用貫通穴の周面とは鈍角を
なし、しかも円管挿入用貫通穴および加工具挿入用貫通
穴の軸線を含む断面において、金型の円管挿入用貫通穴
の周面と加工具挿入用貫通穴の周面とは直角をなすの
で、両貫通穴の境界部分の強度が大きくなり、その破損
を防止できる。Further, according to the present invention, as described above, in the cross section orthogonal to the axis of the through hole for inserting a circular tube, the peripheral surface of the through hole for inserting a circular tube of the mold and the peripheral surface of the through hole for inserting a processing tool. Is an obtuse angle, and in the cross section including the axis of the through hole for inserting a circular tube and the through hole for inserting a processing tool, the peripheral surface of the through hole for inserting a circular tube of the mold and the peripheral surface of the through hole for inserting a processing tool are defined. Since it forms a right angle, the strength at the boundary between the two through holes is increased, and the breakage thereof can be prevented.
第１図はこの発明の方法の実施に用いられる装置の１例
を示す分解斜視図、第２図は同じく円管挿入用貫通穴お
よび加工具挿入用貫通穴の軸線を含む垂直面での断面
図、第３図は第２図のIII−III線断面図、第４図〜第６
図はこの発明による平坦部付き円管の製造方法の１実施
例を工程順に示す第２図相当の垂直断面図、第７図はこ
の発明の方法で製造された平坦部付き円管の斜視図、第
８図は平坦部付き円管からつくったラック棒の斜視図で
ある。 （１）……平坦部付き円管、（２）……平坦部、（10）
……加工具、（11）……の加工面、（11a）……下縁、
（20）……金型、（27）……円管挿入用貫通穴、（28）
……加工具挿入用貫通穴、（40）……素材となる円管、
（40a）……周壁。FIG. 1 is an exploded perspective view showing an example of an apparatus used for carrying out the method of the present invention, and FIG. 2 is a cross-sectional view of a vertical plane including the axis of the through hole for inserting a circular tube and the through hole for inserting a processing tool. FIG. 3 is a sectional view taken along the line III-III of FIG. 2, and FIGS.
FIG. 1 is a vertical sectional view corresponding to FIG. 2 showing one embodiment of a method of manufacturing a circular tube with a flat portion according to the present invention in the order of steps, and FIG. 7 is a perspective view of a circular tube with a flat portion manufactured by the method of the present invention. FIG. 8 is a perspective view of a rack bar made of a circular tube with a flat portion. (1) ... circular tube with flat part, (2) ... flat part, (10)
... processing tool, (11) ... processing surface, (11a) ... lower edge,
(20) ... mold, (27) ... through-hole for circular pipe insertion, (28)
…… through hole for processing tool insertion, (40)… circular pipe as material,
(40a) ... The surrounding wall.
───────────────────────────────────────────────────── フロントページの続き (58)調査した分野(Int.Cl.6，ＤＢ名) B21C 37/15 B29C 53/20 B62D 3/12 ──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. 6 , DB name) B21C 37/15 B29C 53/20 B62D 3/12
Claims (1)
形成されており、かつこの加工面の最下位部分に、前後
から見て円管の周壁の外径よりも小さい所定長さを有す
る直線状部分が設けられている棒状加工具と、前後方向
に伸びるとともに円管を軸線方向に移動自在に挿入しう
る円管挿入用貫通穴、および上下方向に伸びるとともに
下端が円管挿入用貫通穴の内周面に開口し、かつ加工具
をその軸線方向に移動自在に挿入しうる加工具挿入用貫
通穴を備えている金型とよりなり、加工具挿入用貫通穴
の下端開口の左右方向の幅が、棒状加工具下端の加工面
における直線状部分の長さと等しくなされている装置を
使用し、円管を円管挿入用貫通穴内に挿入した後、加工
具を加工具挿入用貫通穴内に挿入するとともに、円管の
周壁の一部が塑性変形するように加工面を周壁に押し付
け、ついで円管をその軸線方向に移動させることにより
平坦部を形成することを特徴とする平坦部付き円管の製
造方法。1. A straight line extending vertically and having a processing surface formed at a lower end, and having a predetermined length smaller than an outer diameter of a peripheral wall of a circular tube when viewed from the front and rear at a lowermost portion of the processing surface. Rod-shaped processing tool provided with a cylindrical part, a through-hole for inserting a circular tube that extends in the front-rear direction, and through which a circular tube can be movably inserted in the axial direction, and a through-hole that extends vertically and has a lower end at the lower end. A die having a through-hole for inserting a processing tool, which can be movably inserted in the axial direction of the processing tool, and a lower end opening of the through-hole for inserting a processing tool. Using a device whose width is equal to the length of the linear portion on the processing surface at the lower end of the rod-shaped processing tool, insert the circular pipe into the through-hole for inserting a circular pipe, and then insert the processing tool into the through-hole for processing tool insertion And a part of the peripheral wall of the pipe is plastic Manufacturing method of the flat portion with the circular tube and forming a flat portion by pressing the peripheral wall of the working surface to form, and then moves the circular tube in the axial direction.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP15463990A JP2920316B2 (en) | 1990-06-13 | 1990-06-13 | Manufacturing method of circular pipe with flat part |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP15463990A JP2920316B2 (en) | 1990-06-13 | 1990-06-13 | Manufacturing method of circular pipe with flat part |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0446629A JPH0446629A (en) | 1992-02-17 |
| JP2920316B2 true JP2920316B2 (en) | 1999-07-19 |
Family
ID=15588612
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP15463990A Expired - Fee Related JP2920316B2 (en) | 1990-06-13 | 1990-06-13 | Manufacturing method of circular pipe with flat part |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2920316B2 (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH04173476A (en) * | 1990-11-06 | 1992-06-22 | Yamada Seisakusho:Kk | Steering rack shaft and manufacture thereof |
| DE102013109454B4 (en) * | 2013-08-30 | 2018-03-22 | Schott Ag | Process for the production and use of a tube with a sectionally deviating from a circular profile and circular end portions and use of a device for producing a pipe |
-
1990
- 1990-06-13 JP JP15463990A patent/JP2920316B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0446629A (en) | 1992-02-17 |
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