JPH05321581A - Driving head - Google Patents

Abstract

PURPOSE:To prevent a driving head from damage and to promote efficiency or work efficiency by going in and out a piston from a head body in the case of driving, and preventing the going in and out of the piston against the head body in the case a burying pipe is pulled in. CONSTITUTION:A group of cylindrical pipe bodies are connected, and a turnable pilot body 3 is provided around the axial center P of a driving head body 1 bending and driving the upper and middle parts thereof. In the case of advancement, a piston 12 is connected to the pilot body 3, pressure oil is continuously supplied and discharged to reciprocate a turning and driving piston, and a driving body is pushed in. In the case of the correction of the direction, the pilot body 3 is projected by an expansion driving mechanism 5 controlling the going in and out of the pilot body 3, and a driving direction is turned to the direction opposite to a moving direction of a pressure receiving section F after earth pressure is received thereby. Then, after a driving head 1 passes through an arrival side, a bearing member is connected to the front end side to pull the burying pipe in the ground. After that, a burying pipe bearing member and the piston 12 are connected to a rotary driving shaft 8, the slippage of the piston 12 from the head body 1A is prevented, and the burying pipe is pulled into the ground.

Description

【発明の詳細な説明】Detailed Description of the Invention

【０００１】[0001]

【産業上の利用分野】本発明は、地中に例えば電力線や
電話線等の配線用の管を埋設するために、地中に小口径
の穴を掘り進め、到達側に貫通したら、埋設用の前記管
を先端側に接続して地中に引き込むのに使用する推進用
ヘッドに関する。更に詳しく説明すると、後方からの押
圧力によって土中を推進する推進体の先端側に連結する
ヘッド本体に内嵌するピストンを、その軸心周りに回転
自在に且つ前記軸心方向に出退操作自在に設け、推進に
伴って土圧を受けて前記ヘッド本体の推進方向を所定の
方向へ導く先導体を、前記ヘッド本体の先端側で前記ピ
ストンに対して着脱自在に連結する連結用第一ボルトを
設け、前記ピストンに対し内嵌して回転駆動機構からの
回転力を伝達する回転駆動軸を設けた推進用ヘッドに関
する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is for burying a pipe for wiring such as a power line or a telephone line in the ground. Of the propulsion head used for connecting the pipe to the tip side and pulling it into the ground. More specifically, a piston that is internally fitted to a head body that is connected to the tip side of a propelling body that is propelled in the soil by a pressing force from the rear is rotatably rotatable about its axis and is retracted in the axis direction. A first connecting body that is freely provided and that detachably connects a leading conductor that receives earth pressure during propulsion to guide the propelling direction of the head body in a predetermined direction to the piston at the tip side of the head body. The present invention relates to a propulsion head provided with a bolt and a rotary drive shaft which is fitted into the piston and transmits the rotational force from the rotary drive mechanism.

【０００２】[0002]

【従来の技術】この種の推進用ヘッドは、前記第一ボル
ト螺合用の第一雌ネジ部を前記ピストンに設け、推進完
了後の埋設用管の地中への引き込みに際して、前記ピス
トンと前記埋設用管とを連結するのに、前記ピストンの
第一雌ネジ部に、前記埋設管と連結した前記第一ボルト
を螺合させて実施するものがあった。2. Description of the Related Art In this type of propulsion head, the piston is provided with a first female screw portion for screwing the first bolt, and when the embedding pipe is pulled into the ground after completion of the propulsion, the piston and the In order to connect the burying pipe, there has been a method in which the first female screw portion of the piston is screwed with the first bolt connected to the burying pipe.

【０００３】[0003]

【発明が解決しようとする課題】従来の推進用ヘッドに
よると、前記第一ボルトによって前記ピストンと前記埋
設用管とを連結した状態で、推進用ヘッドを発進側へ引
き戻すと、それに連なって埋設用管を、推進用ヘッドの
到達側から発進側に向けて地中に引き込むことが出来
る。According to the conventional propulsion head, when the propulsion head is pulled back to the starting side in a state where the piston and the embedding pipe are connected by the first bolt, the propulsion head is continuously embedded. The pipe can be pulled into the ground from the reaching side of the propulsion head toward the starting side.

【０００４】しかし、前記ピストンは、ヘッド本体に対
して、内嵌状態でその軸心周りに回転自在に且つ前記軸
心方向に出退自在であるために、埋設用管の引き込みに
際して、前記ピストンは、ストローク分の全てがヘッド
本体から引き出された状態に露出すると共に、ヘッド本
体の全長がそれに伴って長くなる。However, since the piston is rotatable with respect to the axial center of the head main body and retractable in the axial direction with respect to the head main body, the piston is retracted when the burying pipe is retracted. Is exposed in a state in which all the strokes are pulled out from the head main body, and the total length of the head main body becomes longer accordingly.

【０００５】上述の状態で埋設用管の地中への引き込み
を継続すれば、露出されたピストン外周部は、土に強く
接触して傷つけられる危険性があり、更に、カーブ推進
部を引き戻す場合には、ヘッド本体が伸長しているの
で、そのカーブに沿えきれずに、曲がったり破損したり
する問題がある。If the burial pipe is continuously pulled into the ground in the above-mentioned state, the exposed outer peripheral portion of the piston may be damaged due to strong contact with the soil, and further when the curve propulsion portion is pulled back. However, since the head body is extended, the head cannot bend along the curve and is bent or damaged.

【０００６】そこで、本発明の目的は、上述した問題点
を解消し、ヘッド本体に対して、ピストンの出退を阻止
することが出来る推進用ヘッドを提供するところにあ
る。Therefore, an object of the present invention is to solve the above-mentioned problems and to provide a propulsion head capable of preventing the piston from moving in and out of the head body.

【０００７】[0007]

【課題を解決するための手段】この目的を達成するため
の本発明の推進用ヘッドにおける特徴構成は、ヘッド本
体に内嵌すると共にそのヘッド本体の先端側で軸心周り
に回転自在に且つ前記軸心方向に出退操作自在なピスト
ンに対して、推進に伴って土圧を受けて前記ヘッド本体
の推進方向を所定の方向へ導く先導体を、着脱自在に連
結する連結用第一ボルトの径より小径の第二ボルトが、
前記ピストンに形成された前記第一ボルト螺合用の第一
雌ネジ部を通して螺合可能な第二雌ネジ部を、前記ピス
トンに対し内嵌した状態で回転駆動機構からの回転力を
伝達する回転駆動軸に設けてあるところにある。To achieve this object, the propulsion head of the present invention is characterized in that the propulsion head is fitted in the head body and is rotatable about the axis at the tip side of the head body. With respect to the piston that can be operated to move back and forth in the axial direction, the first conductor for connection that detachably connects the front conductor that receives the earth pressure accompanying the propulsion and guides the propulsion direction of the head main body to the predetermined direction. The second bolt, which is smaller than the diameter,
A rotation for transmitting a rotational force from a rotation drive mechanism in a state in which a second female screw portion that can be screwed through the first female screw portion for screwing the first bolt formed on the piston is internally fitted to the piston. It is located on the drive shaft.

【０００８】[0008]

【作用】本発明の推進用ヘッドにおける特徴構成によれ
ば、ヘッド本体に内嵌すると共にそのヘッド本体の先端
側で軸心周りに回転自在に且つ前記軸心方向に出退操作
自在なピストンに対して、推進に伴って土圧を受けて前
記ヘッド本体の推進方向を所定の方向へ導く先導体を、
着脱自在に連結する連結用第一ボルトの径より小径の第
二ボルトが、前記ピストンに形成された前記第一ボルト
螺合用の第一雌ネジ部を通して螺合可能な第二雌ネジ部
を、前記ピストンに対し内嵌した状態で回転駆動機構か
らの回転力を伝達する回転駆動軸に設けてあるから、例
えば、引込用管を推進用ヘッドに連結する際に、前記第
二ボルトを、ピストンの第一雌ネジ部を通して回転駆動
軸に設けた第二雌ネジ部と螺合させることで、前記引込
用管及び回転駆動軸及びピストンを連結することがで
き、前記ピストンは、ヘッド本体からの出退を阻止され
るので、従来のように、管の引き込みに伴って、ピスト
ンが引き出される事もなく、ヘッドを傷つけたり破損さ
せたりすることを防止することが可能となる。According to the characteristic construction of the propulsion head of the present invention, the piston is fitted in the head main body and is rotatable around the axial center on the tip end side of the head main body and can be operated to move back and forth in the axial direction. On the other hand, a tip conductor that receives earth pressure along with propulsion and guides the propulsion direction of the head main body to a predetermined direction,
A second bolt having a diameter smaller than the diameter of the first bolt for connection that is detachably connected, a second female screw portion that can be screwed through the first female screw portion for screwing the first bolt formed on the piston, Since it is provided on the rotary drive shaft that transmits the rotational force from the rotary drive mechanism in a state of being fitted in the piston, for example, when connecting the retracting pipe to the propulsion head, the second bolt is It is possible to connect the pull-in pipe, the rotary drive shaft and the piston by screwing them together with the second female screw part provided on the rotary drive shaft through the first female screw part of the head. Since the withdrawal is prevented, it is possible to prevent the head from being damaged or damaged without the piston being withdrawn as in the conventional case when the tube is withdrawn.

【０００９】また、前記第二雌ネジ部の内径を、前記第
一雌ネジ部の内径より小さく形成してあるので、第二ボ
ルトの螺合は許容しても、第一ボルトは、螺合できない
から、例えば、誤って、推進時に第一ボルトを第二雌ネ
ジ部に螺合させてピストンが出退できなくなるといった
ことを防ぐことが出来る。Further, since the inner diameter of the second female screw portion is formed to be smaller than the inner diameter of the first female screw portion, the first bolt can be screwed even though the second bolt can be screwed. Therefore, it is possible to prevent, for example, accidentally screwing the first bolt into the second female threaded portion at the time of propulsion to prevent the piston from retracting.

【００１０】[0010]

【発明の効果】本発明の推進用ヘッドによれば、推進時
にはヘッド本体に対してピストンの出退を許容すること
ができる一方、管引き込み時には、ヘッド本体に対して
ピストンの出退を阻止することができるようになり、推
進にも管引きこみにも効率よく使用できるようになっ
た。According to the propulsion head of the present invention, the piston can be allowed to move in and out of the head body during propulsion, while the piston can be prevented from moving in and out of the head body when the pipe is pulled in. It has become possible to use it efficiently for both propulsion and pipe withdrawal.

【００１１】[0011]

【実施例】以下に、本発明の実施例を図面の記載に基づ
いて説明する。図１・図２・図３に示すように、個々の
外面が円筒状面をなす管体群、即ち外面円筒状面の推進
用ヘッド１及び外面円筒状面の複数の推進体２よりなる
小口径（例えば口径１００ｍｍ前後、あるいはそれ以下
程度）の管体群を、継手部Ｊを介して屈曲自在に連結す
ることにより、前記管体群を土中において屈曲させつつ
図外の押し込み装置により推進させるように推進体２を
構成してある。Embodiments of the present invention will be described below with reference to the drawings. As shown in FIG. 1, FIG. 2, and FIG. 3, each of the outer surfaces is a tube group having a cylindrical surface, that is, a small head composed of a propulsion head 1 having an outer cylindrical surface and a plurality of propulsion bodies 2 having an outer cylindrical surface. A pipe group having a diameter (for example, around 100 mm or less) is flexibly connected through a joint J, so that the pipe group is bent in the soil and propelled by a pushing device (not shown). The propelling body 2 is configured so as to allow it.

【００１２】前記推進用ヘッド１は、図に示すように円
筒状の推進用ヘッド本体１Ａと、そのヘッド本体１Ａに
対して長手方向に沿う軸心Ｐ周りで回動自在な先導体３
とから構成されているとともに、前記先導体３をヘッド
本体１Ａの軸心Ｐ周りに回転操作する回転駆動機構４
と、前記先導体３をヘッド本体１Ａに対して軸心Ｐ方向
で出退操作する伸縮駆動機構５とを備えている。As shown in the figure, the propulsion head 1 has a cylindrical propulsion head body 1A and a front conductor 3 which is rotatable about an axis P along the longitudinal direction with respect to the head body 1A.
And a rotary drive mechanism 4 for rotating the front conductor 3 around the axis P of the head body 1A.
And a retractable drive mechanism 5 for operating the leading conductor 3 in and out of the head body 1A in the direction of the axis P.

【００１３】前記先導体３は、前記ヘッド本体１Ａに枢
支された回転駆動軸８と前記先導体３に連設されたピス
トン１２の筒状孔１４との嵌合、および、前記ピストン
１２とそのピストン１２に外嵌するヘッド本体１Ａのシ
リンダー部１３との嵌合により、前記ヘッド本体１Ａに
対して、相対回動ならびに軸心Ｐ方向で相対移動自在に
支承されている。そして、この先導体３には、前記推進
体２を地中推進させるに伴って土圧を受けて、推進方向
をヘッド本体１Ａの軸心Ｐ方向から逸れる方向へ変換す
る受圧部Ｆを設けてある。The tip conductor 3 is fitted with a rotary drive shaft 8 pivotally supported by the head body 1A and a cylindrical hole 14 of a piston 12 connected to the tip conductor 3, and the piston 12 and By fitting with the cylinder portion 13 of the head main body 1A which is fitted onto the piston 12, the head main body 1A is supported so as to be relatively rotatable and relatively movable in the axis P direction. The front conductor 3 is provided with a pressure receiving portion F which receives earth pressure as the propelling body 2 is propelled into the ground and changes the propelling direction to a direction deviating from the axial center P direction of the head body 1A. ..

【００１４】前記回転駆動機構４は、推進用ヘッド本体
１Ａの内周面の一部に形成された螺旋溝６と、その螺旋
溝６に螺合する螺合凸部７ａを備えて前記推進用ヘッド
本体１Ａに内嵌する回転駆動用ピストン７と、前記回転
駆動用ピストン７の内面側に形成されたスプライン孔部
７ｂと噛合するスプライン軸部８ａを外周部に形成した
回転駆動軸８と、前記回転駆動用ピストン７のピストン
ヘッド７ｃの両側部の受圧室１０に圧力流体の一例であ
る圧油を給排してこの回転駆動用ピストン７をヘッド本
体１Ａの軸心Ｐ方向で往復移動させる一対の圧力流体流
路９Ａ・９Ｂとを備えてなる。The rotary drive mechanism 4 is provided with a spiral groove 6 formed in a part of the inner peripheral surface of the propulsion head main body 1A and a screwing convex portion 7a screwed into the spiral groove 6 for the propulsion. A rotary drive piston 7 fitted in the head body 1A, and a rotary drive shaft 8 having an outer peripheral portion with a spline shaft portion 8a meshing with a spline hole portion 7b formed on the inner surface side of the rotary drive piston 7. Pressure oil, which is an example of pressure fluid, is supplied to and discharged from the pressure receiving chambers 10 on both sides of the piston head 7c of the rotary drive piston 7 to reciprocate the rotary drive piston 7 in the axial center P direction of the head body 1A. It is provided with a pair of pressure fluid flow paths 9A and 9B.

【００１５】前記伸縮駆動機構５は、前記回転駆動軸８
に対して軸心Ｐ方向で摺動自在に外嵌するように前記先
導体３に一体連結された有底筒状のピストン１２と、そ
のピストン１２を内装するヘッド本体１Ａのシリンダー
部１３と、前記シリンダー部１３の内部空間に対して前
記回転駆動軸８内に形成された伸縮駆動用給排路１１を
介して圧油を供給する圧力流体供給装置（図外）とから
構成されている。The extension / contraction drive mechanism 5 includes the rotation drive shaft 8
A bottomed cylindrical piston 12 that is integrally connected to the front conductor 3 so as to be slidably fitted in the axial center P direction, and a cylinder portion 13 of the head body 1A that houses the piston 12. It is composed of a pressure fluid supply device (not shown) for supplying pressure oil to the internal space of the cylinder portion 13 through a telescopic drive supply / discharge passage 11 formed in the rotary drive shaft 8.

【００１６】この伸縮駆動機構５は、前記ピストン１２
の内底部および前記ピストン１２の推進方向とは反対側
の端面との双方に夫々受圧面１２ａ，１４ａを設けて、
１２ａの受圧面と前記回転駆動軸８の推進方向側の端面
間および１４ａの受圧面とシリンダー部１３内面との間
に夫々前方圧力室１５・後方圧力室１６を形成してあ
る。そして、前記両圧力室１５，１６に対して圧力流体
供給装置側からの圧油の流通を許す伸縮駆動用給排路１
１を設けてある。また、前方圧力室１５と後方圧力室１
６間については、前記回転駆動軸８の外周面に形成され
たスプライン部８ｂに対して、前記ピストン１２の筒状
孔１４に、圧油の流通を許容する程度の間溝を設けて伸
縮駆動用給排路１１を形成してある。The extension / contraction drive mechanism 5 includes the piston 12
Pressure-receiving surfaces 12a and 14a are provided on both the inner bottom portion and the end surface of the piston 12 opposite to the propelling direction,
A front pressure chamber 15 and a rear pressure chamber 16 are formed between the pressure receiving surface of 12a and the end surface of the rotary drive shaft 8 on the propelling direction side and between the pressure receiving surface of 14a and the inner surface of the cylinder portion 13, respectively. Further, the expansion / contraction drive supply / discharge passage 1 which allows the pressure oil to flow from the pressure fluid supply device side to both the pressure chambers 15 and 16.
1 is provided. In addition, the front pressure chamber 15 and the rear pressure chamber 1
Between 6 and 6, the spline portion 8b formed on the outer peripheral surface of the rotary drive shaft 8 is provided with a groove in the cylindrical hole 14 of the piston 12 as long as the pressure oil is allowed to flow, and the expansion and contraction drive is performed. A supply / discharge passage 11 is formed.

【００１７】一方、ヘッド本体１Ａに対するピストン１
２の最大突出量を規制するピストン突出規制手段は、図
２に示すょうにピストン１２の内側における大径部と小
径部との段差部１７、及び、回転駆動軸８の推進方向側
の端部でピストンの突出に伴って前記段差部１７が接当
する接当部１８とによって形成してある。On the other hand, the piston 1 with respect to the head body 1A
The piston protrusion restricting means for restricting the maximum protrusion amount of 2 includes a step portion 17 between the large diameter portion and the small diameter portion inside the piston 12 and an end portion of the rotary drive shaft 8 on the propulsion direction side as shown in FIG. Is formed by the contact portion 18 with which the step portion 17 contacts as the piston is projected.

【００１８】また、ピストン１２の内底部には、そのピ
ストン１２と先導体３とを連結する第一ボルト１９が螺
合可能な第一雌ネジ部２０を設けてある。A first female screw portion 20 is provided on the inner bottom portion of the piston 12 to which a first bolt 19 connecting the piston 12 and the front conductor 3 can be screwed.

【００１９】一方、回転駆動軸８の推進方向端部には、
前記第一ボルト１９の径より小径の第二ボルト２１が、
ピストン１２に形成された第一ボルト１９螺合用の第一
雌ネジ部２０を通して螺合可能な第二雌ネジ部２２を設
けてある。尚、前記両ボルト１９，２１には、頭部にそ
れぞれ六角レンチ嵌合用の六角穴２３を設けてある。On the other hand, at the end of the rotary drive shaft 8 in the propulsion direction,
A second bolt 21 having a diameter smaller than that of the first bolt 19
A second female screw portion 22 that can be screwed through the first female screw portion 20 for screwing the first bolt 19 formed on the piston 12 is provided. Each of the bolts 19 and 21 has a hexagonal hole 23 for fitting a hexagonal wrench on the head.

【００２０】上記構造の推進体を用いて管体群を直進さ
せる場合は、第一雌ネジ部２０に対して先導体３に挿通
させた第一ボルト１９を螺合させた状態で、前記両圧力
流体流路９Ａ，９Ｂを介しての圧油の給排を連続的に行
って回転駆動用ピストン７を往復移動させ、その往復移
動によって回転駆動軸８即ち先導体３を回転させながら
推進体２を押し込んでいく。また、前記推進体を用いて
方向修正する場合は、先導体３を上述のように回転させ
ずに、旋回させるべき側とは反対側に前記受圧部Ｆを向
けたまま、伸縮駆動機構によって突出させる。そうする
と、受圧部Ｆが土圧を受けて旋回させるべき側に移動し
推進方向は受圧部Ｆの向く方向とは反対方向へ向けられ
る。その後、推進体２を押し込めば、先導体３及びピス
トン１２がヘッド本体１Ａのガイドとなって推進用ヘッ
ド１を旋回させることができる。When the tube group is advanced straight using the propelling body having the above structure, the first female screw portion 20 and the first bolt 19 inserted into the front conductor 3 are screwed together, and The pressure oil is continuously supplied and discharged through the pressure fluid flow paths 9A and 9B to reciprocally move the rotary drive piston 7, and the reciprocal motion causes the rotary drive shaft 8 or the front conductor 3 to rotate while propelling the propellant. Push in 2. Further, when the direction is corrected using the propulsion body, the front conductor 3 is not rotated as described above, and is projected by the expansion / contraction drive mechanism while the pressure receiving portion F is being directed to the side opposite to the side to be swung. Let Then, the pressure receiving portion F receives the earth pressure and moves to the side to be turned, and the propulsion direction is directed in the direction opposite to the direction in which the pressure receiving portion F faces. After that, when the propelling body 2 is pushed in, the leading conductor 3 and the piston 12 serve as a guide for the head main body 1A and the propelling head 1 can be swung.

【００２１】また、例えば、推進用ヘッド１が到達側に
貫通した後、埋設用管支持部材（不図示）を先端側に接
続して地中に埋設用管を引き込むような場合には、前記
第一ボルト１９を第二ボルト２１に取り替えて、前記第
二雌ネジ部２２に対して、前記埋設用管支持部材及びピ
ストン１２等（先導体３を含む場合もある）に挿通させ
た第二ボルト２１を螺合させて、ピストン１２を回転駆
動軸８に連結した状態で引き込みを実施すれば、引き込
み力による、ヘッド本体１Ａからのピストン１２抜け出
しを阻止した状態で埋設用管の地中への引き込みを行う
ことができる。Further, for example, when the propulsion head 1 penetrates to the arrival side and then the burying pipe support member (not shown) is connected to the tip side to pull the burying pipe into the ground, The second bolt 21 is replaced with a second bolt 21, and the second female threaded portion 22 is inserted into the embedding pipe support member, the piston 12 and the like (the leading conductor 3 may be included). If the bolt 12 is screwed and the piston 12 is retracted while being connected to the rotary drive shaft 8, the piston 12 is prevented from coming out of the head body 1A due to the retracting force. Can be retracted.

【００２２】〔別実施例〕以下に、別実施例を説明す
る。[Other Embodiment] Another embodiment will be described below.

【００２３】〈１〉 上記の実施例では、伸縮駆動機構
５として単動型シリンダーの構造を説明したが、段差部
１７と接当部１８との間に圧縮スプリング等の付勢手段
を設けたものや、ピストンを出退駆動させる復動型シリ
ンダーの構造であってもよい。<1> In the above embodiment, the structure of the single-acting type cylinder was described as the expansion / contraction drive mechanism 5. However, a biasing means such as a compression spring is provided between the step portion 17 and the contact portion 18. It may be a structure of a reciprocating cylinder that drives the piston to move in and out.

【００２４】〈２〉 第一ボルト１９・第二ボルト２１
は、先の実施例で説明したそれぞれが別体のものに限定
されるものではなく、例えば、図４に示すように、同一
軸芯上で第一ボルト１９に第二ボルト２１が内嵌するよ
うに形成してあれば、夫々のボルトを取り替える必要が
なく、更にボルトの取り外しによる紛失も防止すること
が出来る。<2> First bolt 19 and second bolt 21
Are not limited to separate members described in the previous embodiments, and for example, as shown in FIG. 4, the second bolt 21 is fitted into the first bolt 19 on the same axis. With this structure, it is not necessary to replace each bolt, and it is possible to prevent the bolt from being lost due to removal.

【００２５】尚、特許請求の範囲の項に図面との対照を
便利にするために符号を記すが、該記入により本発明は
添付図面の構成に限定されるものではない。It should be noted that reference numerals are given in the claims for convenience of comparison with the drawings, but the present invention is not limited to the configurations of the accompanying drawings by the entry.

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

【図１】推進用ヘッドの先端側を表す縦断面図（埋設用
管引き込み時）FIG. 1 is a vertical cross-sectional view showing the tip side of a propulsion head (when a burying pipe is pulled in).

【図２】推進用ヘッドの先端側を表す縦断面図（推進
時）FIG. 2 is a vertical cross-sectional view showing the tip side of a propulsion head (during propulsion).

【図３】推進用ヘッドの基端側を表す縦断面図FIG. 3 is a vertical cross-sectional view showing a base end side of a propulsion head.

【図４】別実施例の第一・第二ボルトを表す図FIG. 4 is a diagram showing first and second bolts of another embodiment.

【符号の説明】[Explanation of symbols]

１Ａ ヘッド本体 ２ 推進体 ３ 先導体 ４ 回転駆動機構 ８ 回転駆動軸 １２ ピストン １９ 第一ボルト ２０ 第一雌ネジ部 ２１ 第二ボルト ２２ 第二雌ネジ部 Ｐ 軸心 1A Head main body 2 Propulsion body 3 Lead conductor 4 Rotation drive mechanism 8 Rotation drive shaft 12 Piston 19 First bolt 20 First female screw portion 21 Second bolt 22 Second female screw portion P P-axis

───────────────────────────────────────────────────── フロントページの続き (72)発明者 辻本 和則 兵庫県尼崎市浜１丁目１番１号 株式会社 クボタ技術開発研究所内 (72)発明者 上中 進 兵庫県尼崎市浜１丁目１番１号 株式会社 クボタ技術開発研究所内 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kazunori Tsujimoto 1-1-1, Hama, Amagasaki-shi, Hyogo Inside Kubota Technology Development Laboratory Inc. (72) Inventor Susumu Kaminaka 1-1-1, Hama, Amagasaki-shi Shares Company Kubota Technology Development Laboratory

Claims (1)

【特許請求の範囲】[Claims] 【請求項１】 後方からの押圧力によって土中を推進す
る推進体（２）の先端側に連結するヘッド本体（１Ａ）
に内嵌するピストン（１２）を、その軸心（Ｐ）周りに
回転自在に且つ前記軸心（Ｐ）方向に出退操作自在に設
け、推進に伴って土圧を受けて前記ヘッド本体（１Ａ）
の推進方向を所定の方向へ導く先導体（３）を、連結用
第一ボルト（１９）によって前記ヘッド本体（１Ａ）の
先端側で前記ピストン（１２）に対して着脱自在に設
け、前記ピストン（１２）に対し内嵌して回転駆動機構
（４）からの回転力を伝達する回転駆動軸（８）を設け
た推進用ヘッドであって、 前記第一ボルト（１９）の径より小径の第二ボルト（２
１）が、前記ピストン（１２）に形成された前記第一ボ
ルト（１９）螺合用の第一雌ネジ部（２０）を通して螺
合可能な第二雌ネジ部（２２）を前記回転駆動軸（８）
に設けた推進用ヘッド。1. A head body (1A) connected to the tip side of a propelling body (2) propelled in the soil by a pressing force from the rear.
A piston (12) which is fitted inside is rotatably provided around the axis (P) and can be operated to move in and out in the direction of the axis (P), and the head main body ( 1A)
A leading conductor (3) for guiding the propelling direction of the piston to a predetermined direction is detachably provided to the piston (12) at the tip end side of the head main body (1A) by a connecting first bolt (19). A propulsion head provided with a rotary drive shaft (8) which is fitted into (12) and transmits the rotational force from the rotary drive mechanism (4), the head having a diameter smaller than that of the first bolt (19). Second bolt (2
1) includes a second female threaded portion (22) screwable through a first female threaded portion (20) for screwing the first bolt (19) formed on the piston (12) to the rotary drive shaft ( 8)
Head for propulsion provided in.