503296 A7 B7 五、發明説明（i 【發明所屬之技術領域】 本發明，係有關於感應電動機之過度負載偵知裝置和 過度負載偵知方法用以偵知感應電動機所受之過度負載， 並可執行預定之保護動作。 【先前之技術】 先前，做爲一般的感應電動機之過度負載偵知方法， 在所受過度負載時因爲旋轉數會變慢使流過電動機之電流 增加，所以用以偵測該電流則可偵知過度負載狀態。又， 用以偵測感應電動機之旋轉數，在異常的旋轉數降低時做 爲過度負載狀態也可進行過度負載偵知。 另外，做爲住宅之防雨板等並在被使用之擋板的開閉 做爲被使用之電動機，對旋轉數之變動使驅動電流之變動 少且直徑小的感應電動機。但是，該感應電動機係因爲使 驅動電流變動少，所以用以監測驅動電流並無法用以偵測 過度負載，使上述旋轉數偵測或其他之機械的偵測方法爲 必要。譬如，做爲機械的電動擋板之異常偵知方法，係被 揭示於日本專利（案）特開平9 - 3 1 0 5 7 3號公報之 偵知方法。該偵知方法，係在擋板之下降中使擋板挾入異 物，則藉由該挾入力使被設於擋板側方之連桿朝向外側並 進行突出，沿著擋板之側方的導軌並將被設置之接點藉由 s亥連桿關閉’用以偵測異常，並能進彳丁緊急停止或反轉動 作。· 又，在擋板之上下限中，也有必要進行偵測並停止電 本紙張尺度適用中國國家標準（CNS ) A4規格（210X297公釐） — ------裝-- (請先聞讀背面之注意事項再填寫本頁) 、tr 線 經濟部智慧財產局員工消費合作社印製 -4 - 503296 A 7 B7 經濟部智慧財產局員工消費合作社印製 五、發明説明（i 動機。該情形，係在上下限用以設置限位開關並使擋板之 端部在達到該位置時藉由限位開關使電動機驅動停止，或 將電動機軸之旋轉角度以機械性或電氣性進行偵測，以設 定値使電動機停止之方法等。 【發明所欲解決之問題】 上述先前技術之情形，在驅動電流變動少的電動機中 能用以偵測過度負載，則用以監測電動機的旋轉數，或必 須採用上述之機械性偵測方法，會使偵知裝置複雜並耗費 成本。進而，此等之偵測方法，係因爲構成形成複雜，所 以做爲裝置在提高信賴性係更耗費成本。 又，在擋板之上下限中使電動機停止時，也會發生與 上述相同的問題點。 本發明係有鑑於上述先前技術之問題點而被發明，其 目的係用以提供感應電動機之過度負載偵知裝置和過度負 載偵知方法使構成簡單且成本低廉，同時信賴性也高。 【解決問題之手段】 本發明，係感應電動機之過度負載偵知裝置具備：感 應電動機，具有進相電容器；及驅動電路，用以驅動該感 應電動機；而感應電動機之過度負載偵知裝置則具備：電 壓偵測裝置，用以偵測上述感應電動機之電壓；及電壓變 動偵測裝置，藉由該電壓偵測裝置在被偵測之電壓用以偵 測產生預定之電壓變動。 (請先閲讀背面之注意事項再填寫本頁)503296 A7 B7 V. Description of the invention (i [Technical field to which the invention belongs] The present invention relates to an over-load detection device and an over-load detection method for an induction motor to detect an over-load on the induction motor. Perform the predetermined protection action. [Previous technology] Previously, as a general method for detecting the overload of an induction motor, the current flowing through the motor will increase due to the slower number of rotations when subjected to the excessive load, so it is used to detect The current can be detected to detect the overload condition. In addition, it is used to detect the number of rotations of the induction motor. When the number of abnormal rotations is reduced, the overload condition can also be detected. In addition, it is used as a defense of the house. Rainboards and the like are used as opening and closing of the used baffle as the used motor, and the change in the number of rotations makes the driving current change small and the diameter of the induction motor small. However, this induction motor is used to make the driving current small. Therefore, monitoring the driving current cannot be used to detect excessive load, so that the above-mentioned rotation number detection or other mechanical detection methods are used. Necessary. For example, an abnormality detection method for a motorized electric baffle is disclosed in Japanese Patent (Laid-Open) Publication No. 9-3 1 0 5 7 3. This detection method is in When the baffle is lowered into a foreign object during the lowering of the baffle, the link provided on the side of the baffle is caused to protrude outward by the driving force, and along the guide rail on the side of the baffle, the connected The point is closed by the lever to detect abnormalities, and can be used for emergency stop or reversing actions. Also, in the upper and lower limits of the baffle, it is necessary to detect and stop the electrical paper size. China National Standard (CNS) A4 specification (210X297 mm) — ------ install-(please read the precautions on the back before filling this page), printed by the Consumer Cooperative of Intellectual Property Bureau of Ministry of Economic Affairs -4-503296 A 7 B7 Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs 5. Inventive Note (i. Motivation. In this case, the upper and lower limits are used to set limit switches and make the end of the baffle reach this position Stop motor drive by limit switch, or motor shaft The rotation angle is detected mechanically or electrically to set a method to stop the motor, etc. [Problems to be Solved by the Invention] The above-mentioned prior art situation can be used to detect an excessive amount in a motor with little variation in drive current. The load is used to monitor the number of rotations of the motor, or the above-mentioned mechanical detection method must be used, which will make the detection device complicated and costly. Furthermore, these detection methods are complicated because of their complicated formation. The device is more costly to improve reliability. When the motor is stopped in the upper and lower limits of the baffle, the same problems as described above also occur. The present invention was invented in view of the problems of the prior art described above. The purpose is to provide an over-load detection device and an over-load detection method for an induction motor, so that the structure is simple, the cost is low, and the reliability is high. [Means for solving the problem] The present invention is an overload detecting device for an induction motor, which includes: an induction motor having a phase advance capacitor; and a driving circuit for driving the induction motor; and an overload detecting device for the induction motor having : A voltage detection device for detecting the voltage of the above induction motor; and a voltage change detection device for detecting a predetermined voltage change at the detected voltage by the voltage detection device. (Please read the notes on the back before filling this page)
J 裝· 訂 線 本紙張尺度適用中.國國家標準（CNS ) A4規格（210X297公釐） -5- 經濟部智慧財產局員工消費合作社印製 503296 A7 _B7_ 五、發明説明（》 又，上述電壓偵測裝置，係用以偵測上述感應電動機 之繞線電壓，或用以偵測進相電容器之兩端電壓。上述感 應電動機，係進行安裝於建築物之擋板的板條之開閉。進 而，上述感應電動機，係在上述板條之捲筒內被同軸設置 。上述感應電動機，係對旋轉數之變動使驅動電流之變動 小者。 又本發明，係一種感應電動機之過度負載偵知方法， 具備：感應電動機，具有進相電容器；及驅動電路，用以 驅動該感應電動機；感應電動機之過度負載偵知方法中， 設置用以偵測上述感應電動機之電壓的電壓偵知裝置，而 該上述電壓偵知裝置，係具備：整流電路，用以半波整流 上述感應電動機之電壓；及波峰偵知裝置，用以檢測該被 整流之半波的波峰電壓；並藉由該波峰偵知裝置將被取得 之信號加以數位處理，在上述波峰電壓產生預定之電壓變 動時，藉由控制裝置使上述感應電動機停止。 進而，一種感應電動機之過度負載偵知方法，使上述 感應電動機之繞線電壓的預定期間之平均値發生預定値以 上變動時，此時電源電壓也進行變動時，係加以忽略該繞 線電壓之變動，而雖然電源電壓無進行變動但使上述繞線 電壓進行變動時，係進行判斷上述感應電動機爲過度負載 〇 又，上述感應電動機之驅動轉矩，係上述擋板之開動 作時係以定格轉矩進行驅動，閉動作時係以比定格轉矩更 低的値可進行驅動並進行過度負載偵知也可。 本紙張尺度適用中國國家標準（CNS ) A4規格（210X 297公釐） I-1.^— 裝 訂 線 (請先閱讀背面之注意事項再填寫本頁) -6 - 503296 A7 B7 五、發明説明（4 【發明之實施形態】 以下’關於本發明之實施形態根據圖式加以說明。圖 1〜圖4係顯示本發明之一實施形態，本實施形態之感應 電動機的電動機1 〇，係如圖1所示，被使用於住宅之擋 雨板等之擋板1 2的開閉。該擋板1 2，係被設置於住宅 之拉門框等之外側，在一對昇降用之導軌1 4、1 5間， 沿著該導軌1 4、1 5使板條1 6在上下方向進行開關。 而在擋板1 2之上方，係使捲起板條1 6並進行收納之收 納部1 8被固設於建築物，在收納部1 8內，使捲繞板條 1 6之捲筒2 0被設置成可正反旋轉。 電動機1 0，係以同軸被設置於該捲筒2 0內，並使 該捲筒2 0正反旋轉。而電動機1 0，係使該電動機1 〇 正反旋轉並使驅動電路2 2被連接，而該電動機驅動電路 2 2，係被連接電壓偵知裝置2 4用以偵測該電動機1 〇 之繞線L 1或L 2之電壓的電壓偵知裝置。 被連接於電動機1 0之配線，係如圖2所示，使被連 接於商用電源2 5之配線通過開關S W並連接於接點c W 及C. C W。而接點C W及C C W，係藉由開關S W切換電 動機1 0之正轉及反轉之接點。 在電壓偵知裝置2 4，係如圖2所示之情形，使電動 機驅動電路2 2之繞線L 2的電壓進行輸入。電壓偵知裝 置2 4，係具備偵知用電阻R 1及半波整流電路3 4，並 使半波整流電路3 4輸出由輸入之控制裝置3 0所構成。 而控制裝置3 0，係具備A /D變換器3 2將由半波整流 本紙張尺度適用中.國國家標準（CNS)A4規格（210x 297公釐） ：--------^-- (請先閲讀背面之注意事項再填寫本頁) 訂 -線 經濟部智慧財產局員工消費合作社印製 經濟部智慧財產局員工消費合作社印製 503296 A7 __ B7 五、發明説明（$ 電路3 4之輸入進行A / D變換。 尙有，在圖2中，將電動機進行正轉時（使開關S W 連接於接點C W時）做爲使擋板1 2之板條1 6降下時， 則使擋板1 2打開時，開關S W係進行連接於接點C C W ，而半整波電路3 4係藉由未圖示之切換開關被外加繞線 L 1之電壓。 該實施形態之感應電動機的過度負載偵知裝置之動作 ，係關於藉由電壓偵知裝置2 4被半波整流之波，如圖3 所示，使控制裝置3 0在預定之抽樣頻率將此時之電壓以 數位收回於控制裝置3 0內，並用以記憶該半波之波峰電 壓。而且用以常時監視各半波之波峰電壓的變動。 譬如，在擋板1 2之閉動作中在板條1 6之下端部使 異物2 6挾住時，或到達擋板之上下端時，如圖4所示， 使電動機1 0之旋轉數急劇下降，電動機電流係幾乎沒有 變化，但使進相電容器C之兩端電壓E C或繞線L 1或 L 2之電壓E L的交流電壓之波峰値大幅下降。因此，被 半波整流之電壓E L之波峰値也大幅降低。而使該波峰値 之預定期間的平均値進行預定値以上變動之時’電動機 1 0之過度負載狀態，將異物2 6挾入，或在擋板1 2之 上下端，所以控制裝置3 0 ’係打開開關S W ’並用以停 止電動機1 0之驅動。 此時過度負載狀態之判斷的臨界値’係用以考慮商用 電源2 5之電源電壓或頻率’並根據擋板1 2之用途或大 小進行設定。又’在過度負載狀態之偵知時用以考慮商用 本紙張尺度適用中.國國家標準（CNS ) A4規格（210X297公釐） J 裝— I I I 訂 I I I I 線 丨** (請先聞讀背面之注意事項再填寫本頁) -8- 經濟部智慧財產局員工消費合作社印製 503296 A7 —_B7 __ 五、發明説明（$ 電源2 5之電壓變動。使電壓E L之預定期間的平均値進 行預定値以上變動時，譬如參考電源電壓之最高値或該最 高値之預定期間的平均値等，而電源電壓也進行變動時， 此時之電壓E L之變動係加以忽視。另外，雖然電源電壓 沒有進行變動但電壓E L進行變動時則加以判斷爲過度負 載。做爲電源2 5之電壓變動，係空調等之投入時的瞬間 電壓下降或在變壓器中使繼電器電路切換時發生瞬間停電 。如此情形係藉由控制裝置3 0，在過度負載之判斷時藉 由加以忽視，可將過度負載偵知之臨界値形成較低者，形 成可高感度的過度負載偵知。 又，電動機1 0之驅動轉矩，係擋板1 2之打開動作 時以定格轉矩進行驅動，閉合動作時係以比定格轉矩更低 之値進行驅動也可。此時之驅動轉矩，係在板條1 6之移 動使必要最小限度之轉矩爲較佳。而轉矩之調整，係譬如 ，在擋板1 2之閉合動作時係在商用電源2 5及電動機 1 0之間能加入電阻並以開關切換，或通過三端雙向開關 並藉由閘之控制將施加電壓進行調整。進而，切換進相電 容器C之容量也可。容量之切換，係進行連動於擋板1 2 之閉合操作並藉由開關在進相電容器C以串聯使其他之電 容器能進行被連接。又，降低轉矩之控制，係使擋板1 2 之板條1 6在下降後之短的預定時間後進行降低也可。 籍此，在擋板1 2之閉合動作時即使人或物被挾入板 條1 6，在少阻力下也會使電動機1 0停止，安全性高。 該實施形態之感應電動機的過度負載偵知裝置，係用 本紙張尺度適用中.國國家標準（CNS ) A4規格（210X297公釐） "— 一 -9 - —. 裝 訂 線 (讀先閲讀背面之注意事項再填寫本頁) 503296 經濟部智慧財產局員工消費合作社印製 A7 _ _B7___五、發明説明（》 以偵測電動機1 〇之繞線L 1、L 2之電壓並能用以偵測 電動機1 0之過度負載，所以使電動機1 0之驅動電流不 管旋轉數在較固定種類之電動機中，也可進行確實之過度 負載偵知。特別，藉由適用在擋板1 2之開關使用之電動 機1 0，在擋板1 2之開閉動作中，即使將異物2 6或人 挾入也可安全確實使電動機1 〇之驅動停止，擋板1 2之 上下端的偵測及電動機1 0之停止也可進行兼用，藉由非 常簡單的構成可進行更正確的動作。 尙有，本發明之感應電動機的過度負載偵知裝置，係 電動機驅動電路2 2之電壓偵知裝置2 4，係使進相電容 器C之兩端電壓輸入於電壓偵知裝置，並進行與上述相同 的動作也可。又本發明之過度負載偵知方法及裝置，係在 擋板開閉用電動機以外，被使用於遮篷之開閉或其他之驅 動裝置也可，並無限定用途。 【發明之效果】 本發明之感應電動機的過度負載偵知裝置及過度負載 偵知方法，係非常簡單的構成，但可進行確實的過度負載 偵測，有助於裝置之小型化及低價格化。又，構成爲簡單 ，而且無機械的可動部，因爲係電氣性構成，所以信賴性 或耐久性高。進而，本發明之感應電動機的過度負載偵知 裝置，係因爲用以核對電壓之變動情形，所以適用於擋板 時，也根據其大小或種類將配合於不同驅動轉矩之大小的 電壓臨界値沒有必要各個進行設定，在過度負載偵知可保 (請先閲讀背面之注意事項再填寫本頁) 裝· 訂 線- 本紙張尺度適用中國國家標準（CNS ) A4規格（210X297公釐） -10- 經濟部智慧財產局員工消費合作社印製 503296 A7 _B7__ 五、發明説明（3 持融通性。 【圖式之簡單說明】 圖1係顯示本發明之一實施形態的過度負載偵知裝置 槪略圖。 圖2係顯示該實施形態之感應電動機的過度負載偵知 裝置之電動機驅動電路槪略圖。 圖3係顯示該實施形態之電壓偵知裝置的半波整流電 路輸出圖。 圖4係顯示該實施形態之感應電動機的過度負載偵知 裝置之電動機特性圖。 【元件編號之說明】 1 0…電動機 1 2…擋板 1 4 ' 1 5 … 導 軌 1 6 · ••板 條 1 8 · ••收容 部 2 0 · ••捲 筒 2 2 . ••電 動 機 驅 動 電路 2 4 · ••電 壓 偵知 裝 置 2 6 · ••異 物 3 0 · ••控 制 裝 置 3 4 . .•半 波 整 流 電 路 本紙張尺度適用中國國家標隼（CNS ) A4規格（210Χ297公釐） . 裝 訂 線 讀 (請先閲讀背面之注意事項再填寫本頁) -11 -J Binding and binding The paper size is applicable. National National Standard (CNS) A4 (210X297 mm) -5- Printed by the Intellectual Property Bureau Employee Consumer Cooperative of the Ministry of Economic Affairs 503296 A7 _B7_ V. Description of the invention ("Again, the above voltage The detection device is used to detect the winding voltage of the above induction motor or to detect the voltage across the phase capacitor. The above induction motor is used to open and close the slats installed on the baffle of the building. The above-mentioned induction motor is coaxially arranged in the reel of the slat. The above-mentioned induction motor is a device that changes the driving current with a small change in the number of rotations. The present invention also relates to a method for detecting an excessive load of an induction motor. It is provided with: an induction motor having a phase advance capacitor; and a driving circuit for driving the induction motor; in an excessive load detection method of the induction motor, a voltage detection device for detecting a voltage of the induction motor is provided, and the The voltage detection device includes: a rectifier circuit for half-wave rectifying the voltage of the induction motor; and a wave detection device To detect the peak voltage of the rectified half-wave; and to digitally process the obtained signal by the peak detection device, and when the peak voltage generates a predetermined voltage fluctuation, the control device makes the induction motor Further, a method for detecting an excessive load of an induction motor, when the average period of the winding voltage of the induction motor for a predetermined period of time exceeds a predetermined value, and when the power supply voltage also changes at this time, the winding is ignored. When the voltage changes and the winding voltage does not change although the power supply voltage does not change, it is determined that the induction motor is overloaded. The driving torque of the induction motor is the time when the baffle is opened. It is driven by fixed torque, and it can be driven and detected by excessive load when it is closed. It is applicable to Chinese National Standard (CNS) A4 (210X 297 mm). -1. ^ — Gutter (please read the notes on the back before filling this page) -6-503296 A7 B7 V. Invention Explanation (4 [Embodiments of the invention] The following describes the embodiments of the present invention based on the drawings. Figures 1 to 4 show one embodiment of the present invention. The motor 1 of the induction motor of this embodiment is as follows. As shown in Fig. 1, the shutters 12 used for the house's windshields and the like are opened and closed. The shutters 12 are installed outside the sliding door frames of the house, etc., on a pair of lifting rails 14, 4, In 15 rooms, the slat 16 is opened and closed along the guide rails 1, 4 and 15. Above the baffle 12, the storage section 18 is rolled up and stored in the slat 16 It is fixed in the building, and the reel 20 of the winding slat 16 is set to be able to rotate forward and backward in the storage portion 18. The motor 10 is coaxially arranged in the reel 20, The reel 20 is rotated forward and backward. The motor 10 rotates the motor 10 forward and backward and connects the driving circuit 22, and the motor driving circuit 22 is connected to the voltage detecting device 24 to detect the winding of the motor 10. Voltage detection device for the voltage of line L 1 or L 2. The wiring connected to the electric motor 10 is shown in Fig. 2 so that the wiring connected to the commercial power source 25 is connected to the contacts c W and C. C W through the switch SW. The contacts C W and C C W are used to switch the forward and reverse contacts of the motor 10 by the switch SW. In the voltage detecting device 24, as shown in Fig. 2, the voltage of the winding L 2 of the motor drive circuit 2 2 is input. The voltage detection device 24 is provided with a detection resistor R1 and a half-wave rectifier circuit 34, and the output of the half-wave rectifier circuit 34 is composed of an input control device 30. The control device 30, which is equipped with A / D converter 32, will be half-wave rectified. The paper size is applicable. National National Standard (CNS) A4 specification (210x 297 mm): -------- ^- -(Please read the notes on the back before filling out this page) Order-printed by the Intellectual Property Bureau of the Ministry of Economic Affairs, printed by the employee consumer cooperatives of the Ministry of Economic Affairs, printed by the employee ’s consumer cooperatives of the Intellectual Property Bureau of the Ministry of Economics, printed by 503296 A7 __ B7 A / D conversion is performed on the input. 尙 Yes, in Figure 2, when the motor is running forward (when the switch SW is connected to the contact CW) as the slat 16 of the baffle 12 is lowered, the When the shutter 12 is opened, the switch SW is connected to the contact CCW, and the half-wave circuit 3 4 is applied with the voltage of the winding L 1 through a switching switch (not shown). The transition of the induction motor in this embodiment is excessive. The operation of the load detection device is related to the half-wave rectified wave by the voltage detection device 24, as shown in FIG. 3, so that the control device 30 will digitally recover the voltage at this time to the control at a predetermined sampling frequency. The device 30 is used to memorize the peak voltage of the half wave. The fluctuation of the peak voltage of each half wave. For example, when the foreign object 26 is caught at the lower end of the slat 16 during the closing operation of the shutter 12 or when it reaches the upper and lower end of the shutter, as shown in FIG. 4 The number of rotations of the motor 10 is drastically reduced, and the motor current is almost unchanged, but the peak value 交流 of the AC voltage of the voltage EC across the phase-feed capacitor C or the voltage EL of the winding L 1 or L 2 is greatly reduced. The peak value 値 of the half-wave rectified voltage EL is also greatly reduced. When the average value of the peak value 预定 for a predetermined period is changed by a predetermined amount or more, the excessive load state of the motor 10 is charged with foreign matter 2 or Above and below the baffle 12, the control device 30 'is to open the switch SW' and is used to stop the driving of the motor 10. At this time, the criticality of the judgment of the excessive load state 値 'is to consider the power of the commercial power supply 25. The voltage or frequency is set according to the purpose or size of the bezel 12. It is also used to consider the commercial paper size in the detection of excessive load. National Standard (CNS) A4 specification (210X297 mm) J Outfit-II I order IIII line 丨 ** (Please read the precautions on the back before filling this page) -8- Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs 503296 A7 —_B7 __ V. Description of the invention When the average EL during a predetermined period of the voltage EL is changed by more than a predetermined value, for example, when the maximum voltage of the power supply voltage or the average value of the maximum period of the maximum voltage is referenced, and the power supply voltage is also changed, the voltage EL at this time The fluctuation is ignored. In addition, although the power supply voltage does not change, the voltage EL is judged to be an excessive load. As the voltage variation of the power supply 25, it is the momentary voltage drop when the air conditioner is turned on or an instantaneous power failure occurs when the relay circuit is switched in the transformer. In this case, the control device 30 can ignore the overload judgment to make the threshold of the overload detection lower, and form a high-sensitivity overload detection. The driving torque of the electric motor 10 may be driven at a fixed torque during the opening operation of the baffle 12, and may be driven at a lower torque than the fixed torque during the closing operation. The driving torque at this time is based on the movement of the slat 16 so that the necessary minimum torque is better. The adjustment of the torque is, for example, that when the baffle 12 is closed, a resistor can be added between the commercial power supply 25 and the motor 10 and switched by a switch, or a three-terminal bidirectional switch and controlled by a brake Adjust the applied voltage. Further, the capacity of the phase-in capacitor C may be switched. The switching of the capacity is performed in conjunction with the closing operation of the baffle 12 and the switch is connected in series with the capacitor C to connect other capacitors in series. The torque reduction control may be performed by lowering the slat 16 of the baffle plate 12 after a short predetermined time after the lowering. Therefore, even when a person or an object is pushed into the slat 16 during the closing operation of the baffle 12, the motor 10 will be stopped with less resistance, and the safety is high. The overload detection device of the induction motor of this embodiment is applicable to the standard of this paper. China National Standard (CNS) A4 specification (210X297 mm) " — -9-—. Binding line (read first read the back Please note this page, please fill in this page) 503296 Printed by A7 _ _B7___ of the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs V. Invention Description ("to detect the voltage of the windings L 1 and L 2 of the motor 10 and can be used to detect The excessive load of the motor 10 is measured, so that the drive current of the motor 10 can be reliably detected regardless of the number of rotations in a relatively fixed type of motor. In particular, it is used by a switch applied to the baffle 12 In the opening and closing operation of the baffle 12, the drive of the motor 10 can be stopped safely and surely even if a foreign object 26 or a person is inserted, the detection of the upper and lower ends of the baffle 12 and the detection of the motor 10 It can also be used for both stop and more accurate operation with a very simple structure. The overload detection device of the induction motor of the present invention is a voltage detection device 2 4 of the motor drive circuit 22, It is also possible to input the voltage across the phase-advancing capacitor C to the voltage detection device and perform the same operation as described above. The over-load detection method and device of the present invention are used in addition to the motor for opening and closing the shutter. The opening and closing of the awning and other driving devices are also possible, and have no limited use. [Effects of the Invention] The over-load detection device and the over-load detection method of the induction motor of the present invention have a very simple structure, but they can be performed reliably. The detection of excessive load contributes to the miniaturization and price reduction of the device. Moreover, since the movable part has a simple structure and has no machinery, it has high reliability or durability because it is electrically constructed. Furthermore, the present invention The excessive load detection device of the induction motor is used to check the change of voltage, so when it is applied to the baffle, it will also match the voltage threshold of different driving torque according to its size or type. It is not necessary to set each individually. It can be guaranteed under the detection of excessive load (please read the precautions on the back before filling this page) Binding · Binding-This paper size is applicable National Standard (CNS) A4 Specification (210X297 mm) -10- Printed by the Intellectual Property Bureau of the Ministry of Economic Affairs Employee Cooperatives 503296 A7 _B7__ V. Description of the Invention (3 Sustainability. [Simplified description of the diagram] Figure 1 shows this FIG. 2 is a schematic diagram of a motor drive circuit of an overload detection device of an induction motor according to an embodiment of the invention. FIG. 3 is a schematic diagram of a voltage detection device of the embodiment according to the present invention. Output diagram of half-wave rectifier circuit. Figure 4 shows the motor characteristic diagram of the overload detection device of the induction motor in this embodiment. [Explanation of component numbers] 1 0… motor 1 2… baffle 1 4 '1 5… rail 1 6 • •• Slat 1 8 • •• Container 2 0 • •• Reel 2 2 • •• Motor Drive Circuit 2 4 • •• Voltage Detector 2 6 Device 3 4.. • Half-wave rectifier circuit This paper size applies to China National Standard (CNS) A4 specification (210 × 297 mm). Binding line read (please read first (Read the notes on the back and fill out this page) -11-