JPH0347810Y2 - - Google Patents
Info
- Publication number
- JPH0347810Y2 JPH0347810Y2 JP10744985U JP10744985U JPH0347810Y2 JP H0347810 Y2 JPH0347810 Y2 JP H0347810Y2 JP 10744985 U JP10744985 U JP 10744985U JP 10744985 U JP10744985 U JP 10744985U JP H0347810 Y2 JPH0347810 Y2 JP H0347810Y2
- Authority
- JP
- Japan
- Prior art keywords
- spindle
- rotation
- rotation speed
- stop
- signal
- 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
Links
- 238000001514 detection method Methods 0.000 claims description 30
- 230000005856 abnormality Effects 0.000 claims description 22
- 230000002159 abnormal effect Effects 0.000 claims description 6
- 238000003754 machining Methods 0.000 description 7
- 238000005516 engineering process Methods 0.000 description 2
- 238000010586 diagram Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
Landscapes
- Automatic Control Of Machine Tools (AREA)
Description
【考案の詳細な説明】 （産業上の利用分野） 本考案は工作機械の異常検出装置に関する。[Detailed explanation of the idea] (Industrial application field) The present invention relates to an abnormality detection device for machine tools.
（従来技術）
工作機械においては、主軸に取り付けた工具の
回転と送りによる加工中に工具に異常負荷が作用
すると刃のチツピングを招くことがある。この対
策として、主軸回転用モータの電源電流値からそ
の過電流を検出した際に主軸送りモータの電源を
遮断させるとともに、設定時間後に主軸回転用モ
ータの電源を遮断する技術が知られている（例え
ば、実開昭60−7943号公報参照）。(Prior Art) In machine tools, if an abnormal load is applied to the tool during machining by rotating and feeding the tool attached to the spindle, chipping of the blade may occur. As a countermeasure against this problem, there is a known technology that cuts off the power to the spindle feed motor when an overcurrent is detected from the power supply current value of the spindle rotation motor, and also cuts off the power to the spindle rotation motor after a set time ( For example, see Utility Model Application Publication No. 60-7943).
この従来技術では、加工中に負荷が弛かに増大
していくときは、負荷変動にかかわらず主軸回転
数が一定になるように電流値を制御していれば、
刃にチツピングを招く前に過電流の検出が可能で
あるが、上記負荷が急激に増大した場合は主軸回
転数が急に低下した後、それに遅れて電流値が高
くなつていくため、過電流が検出された際には既
にチツピングを招いていることがある。 In this conventional technology, when the load increases slowly during machining, if the current value is controlled so that the spindle rotation speed remains constant regardless of load fluctuations,
It is possible to detect an overcurrent before it causes chipping on the blade, but if the load increases rapidly, the spindle rotational speed will suddenly drop, and then the current value will increase with a delay, resulting in an overcurrent. When detected, chipping may have already occurred.
（考案の目的）
本考案は、かかる点に鑑み、加工中に負荷が弛
かに増大する場合だけでなく、負荷が急激に増大
した場合でも、かかる異常を速かに検出して刃の
チツピングを防止することができるようにしよう
とするものである。(Purpose of the invention) In view of the above, the present invention quickly detects abnormalities and prevents the blade from chipping, not only when the load increases slowly during machining, but also when the load increases rapidly. The aim is to make it possible to prevent this.
（考案の構成）
本考案は、工作機械の主軸回転数の異常を設定
回転数との比較で検出する手段と、主軸回転数が
最低回転数以下か否かを検出する手段と、主軸回
転用モータの過電流を検出する手段と、上記回転
数の異常か過電流の少なくとも一方が検出された
際に主軸送りモータに停止信号を送る主軸送り停
止手段と、この停止信号発信から所定時間後に主
軸回転数が最低回転数以下のとき主軸回転用モー
タに停止信号を送る主軸回転停止手段とを備えて
いる。(Structure of the invention) The present invention includes a means for detecting an abnormality in the spindle rotation speed of a machine tool by comparing it with a set rotation speed, a means for detecting whether the spindle rotation speed is below the minimum rotation speed, and a means for detecting an abnormality in the spindle rotation speed of a machine tool by comparing it with a set rotation speed. means for detecting an overcurrent in the motor; a spindle feed stop means for sending a stop signal to the spindle feed motor when at least one of the above-mentioned rotational speed abnormality or overcurrent is detected; The spindle rotation stop means sends a stop signal to the spindle rotation motor when the rotation speed is below the minimum rotation speed.
従つて、本考案の場合、加工中に負荷が弛かに
増大するときはそれが過電流として検出され、負
荷が急激に増大するときはそれが回転数異常とし
て直ちに検出され、主軸の送りが停止されるとと
もに、かかる異常が続いていて主軸回転数が最低
回転数以下になつていると、主軸の回転が停止す
る。 Therefore, in the case of the present invention, when the load increases slowly during machining, it is detected as an overcurrent, and when the load increases rapidly, it is immediately detected as an abnormal rotation speed, and the spindle feed is reduced. If this abnormality continues and the spindle rotational speed falls below the minimum rotational speed, the rotation of the spindle will stop.
（実施例）
本例はマシニングセンターのNC工作機械に関
するものであり、第１図に示す工作機械１におい
て、２はワーク３を取り付けるテーブル、４は工
具５を取り付ける主軸ヘツド、６はツールマガジ
ン、７は主軸回転用モータ、８はワーク３と主軸
ヘツド４との間で相対的な送りを行なう主軸送り
モータである。(Example) This example relates to an NC machine tool for a machining center. In the machine tool 1 shown in FIG. Reference numeral 8 indicates a spindle rotation motor, and 8 a spindle feed motor for relative feeding between the workpiece 3 and the spindle head 4.
上記工作機械１の異常検出装置の具体的構成は
第２図に示されている。 The specific configuration of the abnormality detection device for the machine tool 1 is shown in FIG.
まず、主軸回転用モータ７の定速回転制御系に
ついて説明するに、第２図において、９は主軸回
転用モータ７の回転を検出する回転センサであ
り、その検出信号はFV変換器１０にて電圧に変
換され後述の回転数検出器１１を介し実際の回転
数に比例した電圧として比較器１２に与えられ
る。比較器１２は加工の態様に応じてダイヤル等
で設定されて指令される主軸回転数に対応した電
圧と、上記回転数比例電圧との誤差電圧を得るも
ので、その出力電圧は増幅器１３で増幅ざれ、過
電流検出手段１４を介し主軸回転用モータ７に与
えられる。 First, to explain the constant speed rotation control system of the spindle rotation motor 7, in FIG. The voltage is converted into a voltage and provided to a comparator 12 as a voltage proportional to the actual rotation speed via a rotation speed detector 11, which will be described later. The comparator 12 obtains the error voltage between the voltage corresponding to the spindle rotation speed commanded by setting with a dial etc. according to the processing mode and the rotation speed proportional voltage, and the output voltage is amplified by the amplifier 13. The current is applied to the spindle rotation motor 7 via the overcurrent detection means 14.
しかして、本例の異常検出装置は、異常検出系
として、上記回転数検出器１１と過電流検出手段
１４とを備え、異常検出の場合に主軸制御装置１
５の主軸回転停止手段１６と主軸送り停止手段１
７が作動する。 Therefore, the abnormality detection device of this example includes the rotation speed detector 11 and the overcurrent detection means 14 as an abnormality detection system, and when an abnormality is detected, the main shaft control device 1
5, the main spindle rotation stop means 16 and the main spindle feed stop means 1
7 is activated.
すなわち、回転数検出器１１は、主軸の回転数
が設定回転数以下にダウンしているか否かを検出
する回転数異常検出手段１８と、主軸の回転数が
設定した最低回転数以下か、つまり、実質的にス
ピードゼロか否かを検出する最低回転検出手段１
９とを備える。上記設定回転数は、上述の指令回
転数よりも所定回転数以下の値、つまり回転を継
続するとチツピングを招き易い回転数よりも少し
高い回転数が選ばれており、回転数異常検出手段
１８は、FV変換器１０の出力電圧が上記設定回
転数に対応する電圧以下になると主軸送り停止手
段１７に異常信号を出力する。また、上記最低回
転数は実質的なスピードゼロに対応する例えば
30rpm程度の値に設定されており、最低回転検出
手段１９は、FV変換器１０の出力電圧から回転
速度零を検出すると主軸回転停止手段１６に異常
信号を出力する。 That is, the rotation speed detector 11 includes a rotation speed abnormality detection means 18 that detects whether the rotation speed of the spindle has fallen below a set rotation speed, and a rotation speed abnormality detection means 18 that detects whether the rotation speed of the spindle has fallen below a set minimum rotation speed. , minimum rotation detection means 1 for detecting whether the speed is substantially zero or not.
9. The set rotational speed is selected to be a value lower than a predetermined rotational speed than the commanded rotational speed, that is, a rotational speed slightly higher than the rotational speed at which chipping is likely to occur if the rotation is continued, and the rotational speed abnormality detection means 18 is selected. When the output voltage of the FV converter 10 becomes lower than the voltage corresponding to the set rotation speed, an abnormality signal is output to the spindle feed stop means 17. In addition, the minimum rotation speed mentioned above corresponds to substantially zero speed, e.g.
The minimum rotation detection means 19 outputs an abnormal signal to the spindle rotation stop means 16 when detecting zero rotation speed from the output voltage of the FV converter 10.
過電流検出手段１４は、主軸回転用モータ７の
最大出力トルクに対応する最大電流よりも数％少
ない設定電流値以上の電流を過電流として検出す
るもので、その検出により異常信号を主軸回転停
止手段１６に出力する。 The overcurrent detection means 14 detects as an overcurrent a current exceeding a set current value that is several percent lower than the maximum current corresponding to the maximum output torque of the spindle rotation motor 7, and upon this detection, an abnormal signal is sent to stop the spindle rotation. Output to means 16.
上記主軸送り停止手段１７は、回転数異常検出
手段１８と過電流検出手段１４の少なくとも一方
からの異常信号を受けると、主軸送りモータ８に
対しその通電を遮断する停止信号を出力するもの
であり、停止信号出力からタイマーにより設定さ
れた時間経過後に最低回転検出手段１９に検出指
令信号を出力する。主軸回転停止手段１６は、最
低回転検出手段１９からの異常信号を受けて主軸
回転用モータ７に対し通電を遮断する信号を出力
する。上記タイマーによる設定時間は、上記停止
信号出力から実際に主軸送りが停止するまでの時
間に基いて定められる。 When the spindle feed stop means 17 receives an abnormality signal from at least one of the rotational speed abnormality detection means 18 and the overcurrent detection means 14, it outputs a stop signal to cut off the power supply to the spindle feed motor 8. After the time set by the timer has elapsed since the stop signal was output, a detection command signal is output to the minimum rotation detection means 19. The main shaft rotation stopping means 16 receives the abnormal signal from the minimum rotation detecting means 19 and outputs a signal to cut off the current supply to the main shaft rotation motor 7. The time set by the timer is determined based on the time from when the stop signal is output to when the spindle feed actually stops.
上記主軸制御装置１５の処理の流れは第３図に
示されており、まず、主軸回転の変速中でないこ
とを確認した後、過電流検出か否か、回転ダウン
検出か否か、スピードゼロ検出か否かが判断さ
れ、いずれが検出された場合でも主軸送り停止制
御が行なわれる（ステツプ〜）。そして、過
電流検出あるいは回転ダウン検出の一方もしくは
双方による軸送り停止の場合、タイマーによる所
定時間経過後、スピードゼロが検出されている場
合に主軸回転の停止（オフ）制御が行なわれる
（ステツプ〜）。また、ステツプでのスピー
ドゼロ検出による主軸送りの停止制御が行なわれ
た場合は、直ちに主軸回転の停止制御が行なわれ
る。 The processing flow of the spindle control device 15 is shown in FIG. 3. First, after confirming that the spindle rotation is not being shifted, it is checked whether overcurrent is detected, whether rotation down is detected or not, and zero speed is detected. It is determined whether or not this is the case, and no matter which one is detected, spindle feed stop control is performed (step ~). If the shaft feed is stopped due to overcurrent detection or rotation down detection or both, after a predetermined time has elapsed by the timer, if zero speed is detected, the spindle rotation is stopped (off) control (step ~ ). Furthermore, when the spindle feed is stopped by detecting zero speed in the step, the spindle rotation is immediately stopped.
従つて、上記実施例の場合、加工中の工具５に
対する負荷が徐々に増大し、チツピングが生ずる
前の高い負荷になると、それが過電流として検出
されて主軸送りの停止によりチツピングが防止さ
れる。そして、所定時間後、主軸回転がとまりか
けているときは、主軸回転の停止によりチツピン
グの確実な防止が行なわれ、そうでないときは主
軸の回転を継続し、過電流および回転ダウンが検
出されなくなれば、主軸送りを再開することにな
る。 Therefore, in the case of the above embodiment, when the load on the tool 5 during machining gradually increases and reaches a high load before chipping occurs, this is detected as an overcurrent and chipping is prevented by stopping the spindle feed. . After a predetermined period of time, if the spindle rotation is about to stop, chipping is reliably prevented by stopping the spindle rotation; otherwise, the spindle continues to rotate, and overcurrent and rotation down are no longer detected. If so, spindle feed will be restarted.
また、加工中に工具５に対し急激に負荷が作用
した場合、それが回転ダウンとして検出されて主
軸送りが停止され、上記過電流検出の場合と同様
にしてチツピングの防止がなされる。さらに、こ
の急激な負荷が過大でスピードゼロが検出された
場合は、主軸送り停止制御後、直ちに主軸回転停
止制御が行なわれ、主軸回転用モータ７の破損が
防止される。 Furthermore, if a sudden load is applied to the tool 5 during machining, this is detected as a rotation down and the spindle feed is stopped, thereby preventing chipping in the same manner as in the case of overcurrent detection. Furthermore, if this rapid load is excessive and zero speed is detected, the main spindle rotation stop control is performed immediately after the main spindle feed stop control to prevent damage to the main spindle rotation motor 7.
なお、上記実施例はマニシングセンターに関す
るが、本考案が回転と軸送りを行なう他の工作機
械にも適用できることはもちろんである。 Although the above embodiment relates to a machining center, it goes without saying that the present invention can be applied to other machine tools that perform rotation and axis feeding.
（考案の効果）
本考案によれば、加工中に工具に対する負荷が
徐々に高くなつていつた場合だけでなく、急激に
高い負荷が作用した場合でも速かに異常を検出す
ることができ、刃のチツピング防止が確実とな
る。(Effects of the invention) According to the invention, abnormalities can be quickly detected not only when the load on the tool increases gradually during machining, but also when a sudden high load acts on the tool. This ensures that chipping is prevented.
図面は本考案の実施例を示し、第１図は工作機
械の側面図、第２図は異常検出装置の構成を示す
ブロツク図、第３図は制御における処理のフロー
図である。
４……主軸ヘツド、５……工具、７……主軸回
転用モータ、８……主軸送りモータ、１４……過
電流検出手段、１６……主軸回転停止手段、１７
……主軸送り停止手段、１８……回転数異常検出
手段、１９……最低回転検出手段。
The drawings show an embodiment of the present invention; FIG. 1 is a side view of a machine tool, FIG. 2 is a block diagram showing the configuration of an abnormality detection device, and FIG. 3 is a flow chart of control processing. 4... Spindle head, 5... Tool, 7... Spindle rotation motor, 8... Spindle feed motor, 14... Overcurrent detection means, 16... Spindle rotation stop means, 17
... Spindle feed stop means, 18 ... Rotation speed abnormality detection means, 19 ... Minimum rotation detection means.
Claims (1)
らの信号により主軸の回転数が設定回転数との比
較で異常か否かを検出する回転数異常検出手段
と、上記主軸の回転数が最低回転数以下か否かを
検出する最低回転検出手段と、上記主軸回転用モ
ータの電流値が設定値以上になつているか否かを
検出する過電流検出手段と、上記回転数異常検出
手段と過電流検出手段の少なくとも一方からの異
常信号を受けると上記主軸の送りモータに停止信
号を発する主軸送り停止手段と、上記停止信号発
信から所定時間経過後に上記最低回転検出手段か
らの検出信号を受け主軸の回転数が最低回転数以
下のとき主軸回転用モータに停止信号を発する主
軸回転停止手段とを備えていることを特徴とする
工作機械の異常検出装置。 A rotation speed abnormality detection means for detecting whether or not the rotation speed of the spindle is abnormal in comparison with a set rotation speed based on a signal from a spindle rotation motor that rotates the spindle of the machine tool; minimum rotation detection means for detecting whether or not the current value of the spindle rotation motor exceeds a set value; overcurrent detection means for detecting whether the current value of the spindle rotation motor exceeds a set value; a spindle feed stop means that issues a stop signal to the feed motor of the spindle upon receiving an abnormality signal from at least one of the means; and a spindle feed stop means that receives a detection signal from the minimum rotation detection means after a predetermined time elapses from the generation of the stop signal and rotates the spindle. 1. An abnormality detection device for a machine tool, comprising spindle rotation stop means for issuing a stop signal to a spindle rotation motor when the rotation speed is below a minimum rotation speed.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP10744985U JPH0347810Y2 (en) | 1985-07-12 | 1985-07-12 |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP10744985U JPH0347810Y2 (en) | 1985-07-12 | 1985-07-12 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6215444U JPS6215444U (en) | 1987-01-29 |
| JPH0347810Y2 true JPH0347810Y2 (en) | 1991-10-11 |
Family
ID=30983741
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP10744985U Expired JPH0347810Y2 (en) | 1985-07-12 | 1985-07-12 |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0347810Y2 (en) |
-
1985
- 1985-07-12 JP JP10744985U patent/JPH0347810Y2/ja not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6215444U (en) | 1987-01-29 |
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