JPS62114854A - Tool abnormality detecting device in machine tool - Google Patents

Abstract

PURPOSE:To detect an abnormality of a cutting tool with a high degree of accuracy, by providing, on a plate member capable of transmitting AE waves, an AE sensor and an opening which is approachable surrounding a spindle, and by attaching the plate member to the machine body with the opening being approached to the spindle. CONSTITUTION:When AE waves are generated due to an abnormality of a cutting tool 5, the AE waves are directly transmitted from a cutting tool 5 to a spindle 11 carrying the tool 5, and are then transmitted to a plate member 10 through an opening 12 so that the transmitted AE waves are detected by an AE sensor 9. Since the AE waves substantially directly transmitted from then cutting tool 5 may be detected, no noise and damping caused by bearings occur, and further no affection due to the shape of a workpiece is effected. Thereby, either of breakage, chipping and friction may be all detected at a high S/N ratio with a high degree of accuracy, and therefore, it is possible to detect an abnormality of the tool with a high degree of accuracy.

Description

【発明の詳細な説明】 （発明の分野） 本発明は、機械本体に、先端側に切削工具を着脱自在に
取付ける主軸を駆動回転自在に設けた工作機械において
、前記主軸に着脱自在に取付けられて駆動回転される、
ドリル、バイト、リーマなどの切削工具の異常（折損、
欠け、チッピング、摩耗など）を検出するのに用いられ
るＡＥセンサの取付用プレートに関する。DETAILED DESCRIPTION OF THE INVENTION (Field of the Invention) The present invention relates to a machine tool in which a main shaft, on which a cutting tool is removably attached to the leading end of the machine body, is rotatably provided. driven and rotated,
Abnormalities in cutting tools such as drills, bits, and reamers (breakage,
This invention relates to a mounting plate for an AE sensor used to detect defects (chips, chipping, wear, etc.).

（従来技術とその問題点） 工作機械では、その切削工具において、駆動回転時に上
述のような異常を生じたときに、周波数の高いＡＥ（ア
コースティックエミッション）波を発生することが知ら
れている。そこで、切削工具の加工中（インプロセス）
における異常検出のためにＡＥセンサが用いられている
。このＡＥセンサの使用に際し、従来では、第７図に示
すように構成されていた。(Prior art and its problems) It is known that a machine tool generates a high-frequency AE (acoustic emission) wave when the above-mentioned abnormality occurs in the cutting tool during drive rotation. Therefore, during machining of cutting tools (in-process)
AE sensors are used to detect abnormalities in. Conventionally, when using this AE sensor, the configuration was as shown in FIG. 7.

先ず、工作機械Ａの全体構成について説明すれば、１は
機械本体としての主軸側ケースであり、コラム２に第１
駆動モータ３によって駆動上下移動自在に取付けられて
いる。前記主軸側ケース１には主軸（図省略）が回転自
在に内装され、主軸側ケースｌに取付けられた第２駆動
モータ４と主軸とが伝動ブーりや伝動ギアなどを介して
連動連結され、そして、主軸にはチャックを介してドリ
ルなどの切削工具５が着脱自在に取付けられている。First, to explain the overall configuration of machine tool A, 1 is the main shaft side case as the main body of the machine, and column 2 has a
It is mounted so that it can be driven up and down by a drive motor 3. A main shaft (not shown) is rotatably housed in the main shaft case 1, and the second drive motor 4 attached to the main shaft case 1 and the main shaft are interlocked and connected via a transmission boolean, a transmission gear, etc. A cutting tool 5 such as a drill is detachably attached to the main shaft via a chuck.

コラム２にはベッド６が設けられ、このベッド６上に、
前記切削工具５によって加工されるワーク７が固定支持
されている。８は、切削工具５による加工時に冷却用の
油を供給する給油管である。A bed 6 is provided in the column 2, and on this bed 6,
A workpiece 7 to be machined by the cutting tool 5 is fixedly supported. Reference numeral 8 denotes an oil supply pipe that supplies cooling oil during machining with the cutting tool 5.

このような工作機械Ａに対し、前記ＡＥセンサ９を次の
ように設置していた。The AE sensor 9 was installed in the machine tool A as follows.

■第１従来例 ＡＥセンサ９を主軸側ケースｌの外面に取付け、切削工
具５の異常に伴なうＡＥ波を、切削工具５、主軸、ベア
リングおよび主軸側ケース１を介して１へ１Ｃセンサ９
に伝播させ、そのＡＥ波を検出するように構成していた
。■First conventional example The AE sensor 9 is attached to the outer surface of the spindle side case 1, and the AE waves caused by the abnormality of the cutting tool 5 are transmitted to the 1C sensor 1 via the cutting tool 5, the spindle, the bearing, and the spindle side case 1. 9
The system was configured to propagate the AE waves and detect the AE waves.

■第２従来例 ＡＥセンサ９をベッド６上に取付け、切削工具５の異常
に伴なうＡＥ波を、ワーク７およびベッド６を介してＡ
Ｅセンサ９に伝播させ、そのＡＥ波を検出するように構
成していた。■A second conventional example AE sensor 9 is installed on the bed 6, and the AE wave caused by the abnormality of the cutting tool 5 is transmitted through the workpiece 7 and the bed 6.
The configuration was such that the AE wave was propagated to the E sensor 9 and the AE wave was detected.

なお、第７図では、第１および第２従来例の両方を図示
している。Note that FIG. 7 shows both the first and second conventional examples.

しかしながら、このような構成を有する従来例の場合で
は、それぞれ次のような欠点があった。However, each of the conventional examples having such a configuration has the following drawbacks.

（１）第１従来例の欠点 ベアリングにおいて、回転に伴なうノイズを発生するの
みならず、異常信号として本来的に必要な周波数の高い
ＡＥ波が減衰され、Ｓ／Ｎ比が非常に低下し、折損は検
出できても、欠けやチッピング、摩耗などは検出しづら
く、異常の検出精度が低下する欠点があった。(1) Disadvantages of the first conventional example The bearing not only generates noise due to rotation, but also attenuates high-frequency AE waves that are originally required as abnormal signals, resulting in a very low S/N ratio. However, even if breakage can be detected, it is difficult to detect chips, chipping, wear, etc., and the accuracy of detecting abnormalities is reduced.

（１１）第２従来例の欠点 ワーク７の移動音など、ワーク７やベッド６からレベル
の高い機械的ノイズが発生し、それらのノイズに起因し
て、第１従来例の場合と同様に異常検出精度が低下する
欠点があった。また、ワーク７が大きくて長いものの場
合に、切削工具５が主軸への取付箇所近くで折損すると
、ＡＥ波の減衰量が大きく、その折損すら検出できない
ことがあり、ワーク７の形状に影響を受ける欠点があっ
た。(11) Disadvantages of the second conventional example High-level mechanical noise, such as the sound of the work 7 moving, is generated from the work 7 and the bed 6, and these noises cause abnormalities as in the case of the first conventional example. There was a drawback that detection accuracy decreased. In addition, if the cutting tool 5 breaks near the attachment point to the spindle when the workpiece 7 is large and long, the amount of attenuation of the AE wave is large, and even the breakage may not be detected, which may affect the shape of the workpiece 7. There were some drawbacks.

また、ベッド６がレール上を移動する工作機械では、Ａ
Ｅセノザ９をベッド６上に取付けることができないため
、Ａ　Ｅセンサ９をコラム２側に取付けざるを得す、Ａ
Ｅ波の減衰量がより一層増大ｊ７てＳ／Ｎ比が低下し、
検出精度が一層低下する欠点かあった。In addition, in a machine tool in which the bed 6 moves on rails,
Since the E sensor 9 cannot be installed on the bed 6, the A E sensor 9 must be installed on the column 2 side.
The amount of attenuation of the E wave increases further and the S/N ratio decreases,
The drawback was that the detection accuracy was further reduced.

更に、この上うなへＥセンサ９は、一般に、ワークと冶
具との接触音、ワークの搬送音、他工作機の切削加工時
の発生音などのＡＥ波を含んだノイズが多く発生してい
るノイズ環境の悪い工場で使用されるものであり、それ
らノイズが工作機械の本体そのものに伝播されやすく、
上記第１および第２従来例のものでは、欠けやチッピン
グ、摩耗などの異常の検出精度がどうしても低下（２、
加工不良品の発生防ＩＬの点で改善の余地があった７、
（発明の目的） 本発明は、このような事情に鑑み−こなされたものであ
って、切削上具の主軸への付（Ｊ換えや切削工具の軸径
の相異に支障をきたすことなく、切削工具の異常を精度
良く検出できるようにすることを目的とする。Furthermore, the E-sensor 9 generally generates a lot of noise containing AE waves, such as the contact sound between the workpiece and the jig, the transporting sound of the workpiece, and the sound generated by other machine tools during cutting. It is used in a factory with a poor noise environment, and the noise is easily transmitted to the machine tool itself.
In the first and second conventional examples described above, the accuracy of detecting abnormalities such as chipping, chipping, and wear inevitably decreases (2,
There was room for improvement in terms of IL to prevent the occurrence of defective products7.
(Object of the Invention) The present invention has been made in view of the above circumstances, and is capable of attaching a cutting tool to the main shaft (without causing problems due to J changes or differences in shaft diameter of cutting tools). The purpose of this invention is to enable accurate detection of abnormalities in cutting tools.

（発明の構成と効果） 本発明は、このような目的を達成するために、両頭に記
載した工作機械において、ＡＥ波を伝播可能なプレート
部材に、異常なＡＥ波を検出したときに異常信号を出力
するＡＥセンサと、前記主軸を囲んで近接可能な開口部
とを設け、前記開口部を前記主軸に近接させた状態で前
記プレート部付を前記機械本体に取付けて構成する。(Configuration and Effects of the Invention) In order to achieve such an object, the present invention provides an abnormal signal when an abnormal AE wave is detected in a plate member capable of propagating AE waves in the machine tool described above. An AE sensor that outputs an AE sensor, and an accessible opening that surrounds the main shaft are provided, and the plate attachment is attached to the machine body with the opening in close proximity to the main shaft.

この構成によれば、切削工具の異常に伴なってＡＥ波が
発生すると、そのＡＥ波が、切削工具からそれを取付け
た主軸に直接伝播され、そのＡ　Ｅ波を開口部を介して
プレート部材に伝播させ、その伝播されたＡＥ波をＡＥ
センサによって検出できることとなる。According to this configuration, when an AE wave is generated due to an abnormality in the cutting tool, the AE wave is directly propagated from the cutting tool to the main shaft on which it is attached, and the AE wave is transmitted through the opening to the plate member. The propagated AE wave is
This means that it can be detected by a sensor.

したがって、切削工具からほぼ直接的に伝播されるＡＥ
波を検出できるから、ベアリングに起因するノイズや減
衰が無く、また、ワークの形状による影響を受けること
がなく、折損はもちろんのこと、欠けやチッピング、摩
耗などをもＳ／Ｎ比の高い状態で精度良く検出でき、切
削工具の異常を精確に検出できるようになった。その結
果、欠けやチッピング、摩耗などが発生したまま、継続
して加工不良品を生産するということを回避でき、製品
を歩留まり良く生産できるようになった。Therefore, the AE propagated almost directly from the cutting tool
Since waves can be detected, there is no noise or attenuation caused by bearings, and it is not affected by the shape of the workpiece, so it is possible to detect not only breakage but also chipping, chipping, wear, etc. with a high S/N ratio. It has become possible to accurately detect abnormalities in cutting tools. As a result, it has become possible to avoid the continued production of defective products with defects such as chipping, chipping, and wear, and it has become possible to produce products with a high yield.

更には、例えば、切削工具自体からＡＥ波を検出しよう
とした場合、その主軸に取付けられる切削工具の軸径の
大小変化に起因して開口部の内面と切削工具の軸外面と
の間の距離が変化し、検出精度に影響する問題があり、
また、切削工具を主軸に着脱自在に取付けるときにプレ
ート部材が邪魔になり、切削工具の付は換えのたびにプ
レート部材を退避させる必要があるが、本発明によれば
、主軸に伝播されたＡＥ波を検出するから、切削工具の
種類や主軸への付は換えに何ら支障を生じさせることが
なく、構成および操作のいずれも簡単で便利に使用でき
るようになった。殊に、多数の切削工具を頻繁に付は換
えて加工作業を行なうマシニングセンターに適用するに
おいて、極めて有用である。Furthermore, for example, when attempting to detect AE waves from the cutting tool itself, the distance between the inner surface of the opening and the outer surface of the shaft of the cutting tool may vary due to changes in the shaft diameter of the cutting tool attached to the main shaft. There is a problem that changes in the detection accuracy and affects the detection accuracy.
In addition, the plate member gets in the way when the cutting tool is detachably attached to the spindle, and it is necessary to retract the plate member every time the cutting tool is attached or replaced. Since AE waves are detected, there is no problem with the type of cutting tool or attachment to the spindle, and both the configuration and operation are simple and convenient to use. In particular, it is extremely useful when applied to a machining center where a large number of cutting tools are frequently replaced during machining operations.

（実施例の説明） 以下、本発明を図面に示す実施例に基づいて詳細に説明
する。第１図は、本発明の実施例に係る工作機械におけ
る工具異常検出装置を示す要部の一部切欠側面図、第２
図は、工具検出装置を取付けた状態の工作機械の全体側
面図である。これらの図において、１０は、ＡＥ波を伝
播可能なプレート部材である。このプレート部材ＩＯの
所定箇所に、主軸側ケースｌの下部の主軸頭１ａから下
方に突出された主軸ｔｉを嵌入する開口部１２が形成さ
れている。(Description of Examples) Hereinafter, the present invention will be described in detail based on examples shown in the drawings. FIG. 1 is a partially cutaway side view of a main part showing a tool abnormality detection device for a machine tool according to an embodiment of the present invention, and FIG.
The figure is an overall side view of the machine tool with the tool detection device attached. In these figures, 10 is a plate member capable of propagating AE waves. An opening 12 is formed at a predetermined location of the plate member IO, into which the main shaft ti protruding downward from the main shaft head 1a at the lower part of the main shaft side case l is inserted.

主軸２は、主軸側ケースｌに駆動回転自在に取付けられ
、その主軸■１の下方の突出端にコ１ノット１３を介し
てドリルチャック１４が取付けられ、このドリルチャッ
ク１４に切削工具の一例としてのドリル５が着脱自在に
取付けられている。The main shaft 2 is attached to the main shaft side case 1 so as to be rotatable, and a drill chuck 14 is attached to the lower protruding end of the main shaft 1 via a knot 13. A drill 5 is detachably attached.

前記開口部１２の左右両側それぞれに、ネジ穴１５が形
成され、一対のネジ１６．１６により、スペーサ！７を
介してプレート部材ＩＯが主軸頭１ａに取付支持されて
いる。このネジ穴１５．１５それぞれとネジ■６との間
、ならびに、スペーサ１７．１７とプレート部材１０と
の間それぞれにゴムバッキングを介装し、主軸頭１ａか
らネジ１６．１６およびスペーサ１７．１７それぞれを
介して主軸側ケースｌａ側からノイズが伝播することを
防止し、ＡＥセンサ９による検出精度をより一層向上で
きるようにしても良い。Screw holes 15 are formed on each of the left and right sides of the opening 12, and a pair of screws 16 and 16 are used to secure the spacer! A plate member IO is attached and supported to the spindle head 1a via 7. A rubber backing is interposed between each of the screw holes 15.15 and the screw 6 and between the spacer 17.17 and the plate member 10, and from the spindle head 1a to the screw 16.16 and the spacer 17.17. It is also possible to prevent noise from propagating from the spindle side case la side through each of them, thereby further improving the detection accuracy of the AE sensor 9.

ＡＥセンサ９はマグネットケース１８に収納され、一方
、プレート部材ｌＯは磁性材料によって成形され、マグ
ネットケース夏８をプレート部材１０に磁気吸着するこ
とにより、ＡＥセンサ９をプレート部材ＩＯに取付けら
れるようになっている。The AE sensor 9 is housed in a magnetic case 18, while the plate member IO is formed of a magnetic material, and by magnetically adhering the magnetic case 8 to the plate member 10, the AE sensor 9 can be attached to the plate member IO. It has become.

前記開口部１２の内径は、ドリル５の外径よりもやや犬
に設定され、かっ、その全周にわたり、径方向でのクリ
アランスが０．１ｍｍ以下になるように設定されていて
、開口部１２の内周面を主軸１１の外周面に接触させる
ことなく、ドリル５での折損、欠け、チッピング、摩耗
などの各種異常に伴なって発生するＡＥ波を主軸１１か
らプレート部材１０に良好に伝播できるように構成され
ている。The inner diameter of the opening 12 is set to be slightly larger than the outer diameter of the drill 5, and the clearance in the radial direction is set to be 0.1 mm or less over the entire circumference. AE waves generated due to various abnormalities such as breakage, chipping, chipping, wear, etc. in the drill 5 can be propagated from the main shaft 11 to the plate member 10 without causing the inner peripheral surface of the drill to contact the outer peripheral surface of the main shaft 11. It is configured so that it can be done.

なお、この開口部１２として、その内径をドリル５の外
径よりも比較的大に構成し、開口部１２にドリル５を挿
通した状態で、開口部１２の内周面とドリル５の外周面
との間に、切削油等による油膜やグリスあるいは水など
の、空気の侵入を阻止する液体または液状体を滞留させ
るようにしても良い。The inner diameter of the opening 12 is relatively larger than the outer diameter of the drill 5, and when the drill 5 is inserted through the opening 12, the inner circumferential surface of the opening 12 and the outer circumferential surface of the drill 5 A liquid or a liquid substance, such as an oil film such as cutting oil, grease, or water, which prevents air from entering may be retained between the two.

第３図は、多数の切削工具を付は換え自在に取付けるマ
シニングセンターに適用した他の実施例を示す要部の断
面図、第４図はその要部の拡大断面図である。この実施
例のものでは、主軸１１の下端には、切削工具を保持す
るツールボット■９が取付けられている。そこで、主軸
側ケース１ａの上端から突出された主軸１１の上端側に
おいて、ｍｌ述実施例におけると同様のプレート部材１
０が取付けられている。このプレート部第１０では、そ
の所定箇所にブツシュ２０が圧入され、このブツシュ２
０により前記実施例における開口部が構成されている。FIG. 3 is a cross-sectional view of the main parts of another embodiment applied to a machining center on which a large number of cutting tools are removably attached, and FIG. 4 is an enlarged cross-sectional view of the main parts. In this embodiment, a tool bot 9 for holding a cutting tool is attached to the lower end of the main shaft 11. Therefore, on the upper end side of the main shaft 11 protruding from the upper end of the main shaft side case 1a, a plate member 1 similar to that in the embodiment described above
0 is attached. A bushing 20 is press-fitted into a predetermined location in this plate part 10.
0 constitutes the opening in the above embodiment.

即ち、このように、本発明としては、切削工具５の異常
に伴なって発生するＡＥ波を主軸１１からほぼ直接的に
伝播して検出するものであれば良く、前述のように主軸
ＩＩの下端側あるいは上端側にＡＥセンザ９を設けるも
のに限らず、例えば、主軸＋１の長手方向途中箇所にＡ
Ｅセンサ９を設けるものでも良い。このように途中箇所
に設ける場合であれば、前記プレート部材ＩＯを開口部
Ｉ２またはブツシュ２０を通る線で２分割し、主軸１゛
１を挟むように組み付けてから両分側プレート部材どう
しを一体連結するように構成すれば良い。In other words, the present invention only needs to detect the AE wave generated due to the abnormality of the cutting tool 5 by propagating almost directly from the main shaft 11, and as described above, the AE wave generated due to the abnormality of the cutting tool 5 can be detected by propagating almost directly from the main shaft 11. The AE sensor 9 is not limited to the one where the AE sensor 9 is installed on the lower end side or the upper end side.
An E-sensor 9 may also be provided. If the plate member IO is to be installed in the middle like this, the plate member IO is divided into two along a line passing through the opening I2 or the bush 20, and the two plate members are assembled together so as to sandwich the main shaft 1. It is sufficient to configure them so that they are connected.

上述実施例では、いずれも開口部１２またはブツシュ２
０の内周面と主軸１１の外周面とを近接することにより
、主軸１１からプレート部材１０にＡＥ波を効率良く伝
播させるようにしているが、例えば、第５図に示すよう
に、プレート部材ｌＯの上下において、主軸１１にシー
ル用のゴムバッキング２１．２１を取付け、両ゴムバッ
キング２１．２１で囲まれた空間内に切削油や潤滑油を
充填するとか、また、第６図に示すように、プレート部
材ｌＯと主軸ｔｉとの間に磁性流体による軸受部２２を
形成するなどし、主軸ｔｉからプレート部材ＩＯへのＡ
Ｅ波伝播をより一層効率良く行なわせるようにしても良
い。In the above embodiments, the opening 12 or the bush 2
By bringing the inner circumferential surface of the main shaft 11 and the outer circumferential surface of the main shaft 11 close to each other, the AE waves are efficiently propagated from the main shaft 11 to the plate member 10. For example, as shown in FIG. Attach rubber backings 21.21 for sealing to the main shaft 11 above and below the lO, and fill the space surrounded by both rubber backings 21.21 with cutting oil or lubricating oil, as shown in Fig. 6. In addition, a bearing part 22 made of magnetic fluid is formed between the plate member lO and the main shaft ti, and the A from the main shaft ti to the plate member IO is
E-wave propagation may be carried out even more efficiently.

なお、前記ＡＥセンサ９からの配線２３は周波数判定処
理部（図外）に導かれ、ＡＥ波を検出してドリル５の折
損、欠け、チッピング、摩耗などの各種異常を検出でき
るように構成される。Note that the wiring 23 from the AE sensor 9 is led to a frequency determination processing section (not shown), and is configured to detect AE waves and detect various abnormalities such as breakage, chipping, chipping, and wear of the drill 5. Ru.

前記開口部１２およびブツシュ２０それぞれとしては、
主軸１１の周方向全長にわたるものに限らず、その周方
向の一部が開放されたものでも良い。The opening 12 and bushing 20 each include:
It is not limited to the one that spans the entire circumferential length of the main shaft 11, but may be one that is partially open in the circumferential direction.

上記実施例では、ＡＥセンサ９をマグネットケース１５
により磁力でプレート部材ＩＯに取付け、その取付けを
極めて容易に行なえるようにしているが、本発明として
は、ＡＥセンサ９をビス止めによって取付けるなど各種
の取付構造が採用可能である。In the above embodiment, the AE sensor 9 is connected to the magnetic case 15.
Although the AE sensor 9 is attached to the plate member IO by magnetic force, which makes the attachment extremely easy, the present invention can employ various attachment structures such as attaching the AE sensor 9 with screws.

また、プレート部材ＩＯを工作機械Ａに対して位置固定
するのに、ネジ１６をネジ穴１５に挿通して固定するよ
うにしているが、例えば、板状の部材によりプレート部
材１０を挟み付けて固定するようにしても良く、各種の
支持構造が採用できる。Further, in order to fix the position of the plate member IO with respect to the machine tool A, the screw 16 is inserted into the screw hole 15 and fixed, but for example, the plate member 10 is sandwiched between plate-shaped members. It may be fixed, and various support structures can be adopted.

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

第１図は、本発明の実施例に係る工作機械における工具
異常検出装置を示す要部の一部切欠側面図、第２図は、
工具検出装置を取付けた状態の工作機械の全体側面図、
第３図は、他の実施例を示す要部の断面図、第４図は、
第３図の要部の拡大断面図、第５図および第６図は、そ
れぞれ他の実施例を示す要部の断面図、第７図は、従来
例を示す全体正面図である。 １・・・機械本体としての主軸側ケース、５・・・切削
工具としてのドリル、 ９・・・ＡＥセンザ、 １０・・・プレート部材、 １１・・・主軸、 １２・・・開口部、 ２０・・・開口部としてのブツシュ、 Ａ・・工作機械。FIG. 1 is a partially cutaway side view of a main part showing a tool abnormality detection device for a machine tool according to an embodiment of the present invention, and FIG.
Overall side view of the machine tool with the tool detection device installed,
FIG. 3 is a cross-sectional view of the main parts showing another embodiment, and FIG.
FIG. 3 is an enlarged sectional view of the main part, FIGS. 5 and 6 are sectional views of the main part showing other embodiments, and FIG. 7 is an overall front view showing the conventional example. DESCRIPTION OF SYMBOLS 1... Main shaft side case as machine body, 5... Drill as cutting tool, 9... AE sensor, 10... Plate member, 11... Main shaft, 12... Opening, 20 ...button as an opening, A...machine tool.

Claims (2)

【特許請求の範囲】[Claims] （１）機械本体に、先端側に切削工具を着脱自在に取付
ける主軸を駆動回転自在に設けた工作機械において、 ＡＥ波を伝播可能なプレート部材に、異常なＡＥ波を検
出したときに異常信号を出力するＡＥセンサと、前記主
軸を囲んで近接可能な開口部とを設け、前記開口部を前
記主軸に近接させた状態で前記プレート部材を前記機械
本体に取付けてあることを特徴とする工作機械における
工具異常検出装置。(1) In a machine tool that has a rotatable spindle on which a cutting tool is removably attached to the tip of the machine body, an abnormal signal is generated when abnormal AE waves are detected in a plate member that can propagate AE waves. an AE sensor that outputs an AE sensor, and an opening that surrounds the main shaft so that it can be approached, and the plate member is attached to the machine body with the opening close to the main shaft. Tool abnormality detection device for machines. （２）前記開口部が前記プレート部材に圧入したブッシ
ュである前記特許請求の範囲第１項に 記載の工作機械における工具異常検出装置。(2) The tool abnormality detection device for a machine tool according to claim 1, wherein the opening is a bush press-fitted into the plate member.