201223122 六、發明說明： 【發明所屬之技術領域】 本發明係關於馬達制動裝置及馬達控制方法，特別是 關於利用動力制動之馬達制動裝置及馬達控制方法。 【先前技術】 於馬達作動時作用的動力制動，係利用於鐵路車輛等 之制動’且已經過各種改良。例如，專利文獻1針對驅動 馬達之控制方法，提案有一種動力制動，其係於主電路隔 斷等非常停止時，使同時觸發驅動馬達的功率電晶體之上 側或下側電晶體之比率，在制動中變化，並使其配合機械 減速且停止。 〔先行技術文獻〕 〔專利文獻〕 〔專利文獻1〕日本特開2007-3 73 8 2號公報 【發明內容】 〔發明所欲解決之課題〕 但是，以往的動力制動所用的動力制動電路或馬達控 制裝置，通常是藉由來自外部控制器的指令訊號而獲得對 馬達施加制動的時序，因此於選擇外加動力制動裝置之情 形下，爲了指導時序而必須有専用的訊號線。 本發明係爲了解決上述課題而發硏發者，其課題在於 -5- 201223122 提供判斷施加制動之時序且對馬達施加制動的馬達制動裝 置及馬達控制方法。 〔解決課題之手段〕 爲了解決上述課題，本發明之特徵在於具備：電壓檢 測部，用以檢測馬達的端子間之端子間電壓；頻率、電壓 轉換部，用以將前述端子間電壓之頻率轉換成電壓値予以 輸出；電壓比較部，係比較自前述頻率、電壓轉換部輸出 之電壓値、和預定臨界値電壓；及制動部，係根據前述電 壓比較部的比較結果而對馬達施加制動。 〔發明效果〕 本發明係藉由檢測馬達的端子間之端子間電壓，將端 子間電壓之頻率轉換成電壓値予以輸出，且根據比較該已 輸出之電壓値和預定臨界値電壓的結果來對馬達施加制動 ，而可提供判斷施加制動之時序來對馬達施加制動之馬達 制動裝置及馬達控制方法。 【實施方式】 首先，利用圖1說明關於本發明之一實施形態之馬達 控制系統的構成及槪要功能。 圖1係關於本發明之實施形態之馬達控制系統的槪略 構成之一例的方塊圖。 如圖1所示，馬達控制系統1具備：利用三相交流予以 -6 - 201223122 驅動之馬達2，及供給用以作動馬達2的電力之馬達驅動裝 置3 ’以及對馬達2施加制動的馬達制動裝置1 0。 馬達2具有端子2a用以接受來自馬達驅動裝置3的電力 供給。馬達2係線性馬達或旋轉馬達，具有藉由磁性之作 用而互相地相對運動之固定子及可動子（或旋轉子），該 等係由線圈或永久磁鐵形成。該線圈係連接在端子2a。又 ’馬達2係伺服馬達，具有檢測馬達2之狀態的感測器（無 圖示），該感測器連接在馬達驅動裝置3。 馬達驅動裝置3具有對馬達供給電力之輸出端子3a， 且將由電源裝置供給的電力轉換成三相交流，通過馬達制 動裝置10而對馬達2供給電力。輸出端子3 a係由U相用、V 相用及W相用的端子所形成。又，馬達驅動裝置3係由上 位控制器（無圖示）控制，根據上位控制器的指令而將馬 達2設定於伺服ON之狀態並對馬達2供給電力，或設定於 伺服OFF之狀態而停止電力供給。 馬達制動裝置10具有：用以連接馬達驅動裝置3的輸 出之輸入端子11;用以連接馬達的端子之輸出端子12;用 以連接輸入端子1 1和輸出端子1 2之導線1 3 ;用以檢測馬達 2的端子2a間的端子間電壓之電壓檢測部1 5 ;用以將端子 間電壓的頻率轉換成電壓値予以輸出之頻率、電壓轉換（ F/V )部1 6 ;比較從頻率、電壓轉換部1 6輸出之電壓値、 和預定臨界値電壓之電壓比較部17;根據電壓比較部17的 比較結果而控制馬達2的制動之控制部1 8 ;及根據控制部 1 8之控制而對馬達2施加制動之制動部20。 201223122 輸入端子11連接於馬達驅動裝置3的各輸出端子3a， 用以接受供給馬達2的電力。 輸出端子12連接於馬達2的各端子2a，用以將來自馬 達驅動裝置3的電力供給至馬達2。 導線1 3具有ϋ相用導線1 3 u、V相用導線1 3 v及W相用導 線13w。U相用導線13u和V相用導線13ν連接電壓檢測部15 。此外，電壓檢測部15宜連接U相用導線13u、V相用導線 13ν及W相用導線13w中的任意兩者。又，U相用導線13u、 V相用導線13v及W相用導線13w連接制動部20，當動力制 動作動時，馬達2產生的逆起電力係於制動部20消耗。 電壓檢測部1 5檢測導線1 3間的電壓，且輸出至頻率、 電壓轉換部16。 頻率、電壓轉換部16具有F/V轉換器，用以將由電壓 檢測部15檢測到的電壓之脈衝頻率，轉換成配合脈衝頻率 之電壓値。 電壓比較部17具有比較器，用以輸出比較頻率、電壓 轉換部16的輸出電壓値、和第1臨界値及第2臨界値之比較 結果。 控制部1 8係於第1臨界値以下時，輸出使制動部20的 制動動作的開關爲ON (開啓）之訊號，於第2臨界値以上 時，輸出使制動部20的制動動作的開關爲OFF (斷開）之 訊號。 制動部20具有：動力制動電晶體（DB電晶體）21，係 電晶體元件的一例；動力制動電阻器（DB電阻器）22，係 201223122 電阻器的一例，使在馬達2產生的逆起電力轉換成熱能； 及整流電路23，係藉由整流二極體將馬達2產生的逆起電 力予以整流。 接著，利用圖2至圖4說明馬達控制系統1的動作。 圖2係顯示馬達制動裝置1 0的動力制動之動作例的流 程圖。圖3係顯示馬達2的端子間的電壓之時間性變化之一 例的線圖。圖4係顯示馬達制動裝置1 0的制動解除的動作 例之流程圖。 首先，說明關於馬達制動裝置1 0對馬達2施加動力制 動時的動作。 如圖2所示，電壓檢測部15檢測馬達2的端子間電壓（ 步驟S1 )。具體而言，電壓檢測部15檢測馬達2的端子2a 所連接之導線1 3間的電壓，且將檢測到的電壓輸出至頻率 、電壓轉換部1 6。 如圖3所示，馬達驅動裝置3係於伺服ON之狀態下， 輸出某一定頻率的電壓脈衝。該電壓脈衝配合流過馬達2 的電流之頻率，使電壓的正負反轉。此外，電壓脈衝的頻 率比流過馬達2的電流之頻率高，亦即比馬達2旋轉的頻率 高。 接著，頻率、電壓轉換部1 6係將由電壓檢測部1 5所檢 測到的電壓之頻率轉換成配合頻率之電壓値（步驟S2 )。 具體而言，頻率、電壓轉換部16係將電壓脈衝的頻率轉換 成配合電壓脈衝的頻率之電壓値。頻率、電壓轉換部丨6係 頻率愈高則輸出愈高的電壓値。 -9 - 201223122 接著，電壓比較部17判斷頻率、電壓轉換部16的輸出 電壓値是否爲第1臨界値電壓以下（步驟S3)。如圖3所示 ’於伺服ON之狀態下，馬達驅動裝置3輸出高頻率的電壓 脈衝，因此頻率、電壓轉換部16的輸出電壓値比第1臨界 値電壓還高（步驟S3 ; NO )，回到步驟S 1，電壓檢測部 15檢測電壓。 另一方面，成爲伺服OFF之狀態時，馬達驅動裝置3停 止電壓脈衝的輸出。一旦停止電壓脈衝的輸出，則如圖3 所示，馬達2的端子間出現對應馬達2的旋轉之逆起電力的 電壓波形。於此情形，由於旋轉的頻率比電壓脈衝的頻率 低，因此頻率、電壓轉換部16的輸出電壓値成爲第1臨界 値電壓以下（步驟S3 ; YES )，控制部1 8使制動部20的DB 電晶體21爲ON (步驟S4)。一旦DB電晶體21成爲ON，馬 達2的逆起電力所產生的電流流過DB電阻器22且轉換成熱 能，使制動部20對馬達2施加動力制動。 接著，說明關於馬達制動裝置1 0的制動解除之動作》 其係於使馬達2驅動時，或爲了制動過於未解除之動作。 如圖4所示，電壓檢測部1 5檢測馬達2的端子間電壓（ 步驟S 5 )。與步驟S 1同樣，但例如於馬達2停止之狀態下 ，於未從馬達驅動裝置3供給電力之狀態時，馬達2的端子 間電壓爲零。 接著，頻率、電壓轉換部1 6係將由電壓檢測部1 5檢測 到的電壓之頻率轉換成配合頻率之電壓値予以輸出（步驟 S6 )。例如，馬達2的端子間電壓爲零時，無法檢測電壓 -10- 201223122 而頻率亦爲零，頻率、電壓轉換部16的輸出電壓値成爲零 〇 接著，電壓比較部17判斷頻率、電壓轉換部16的輸出 電壓値是否爲第2臨界値電壓以上（步驟S7)。例如，於 馬達2的端子間電壓爲零之情形，頻率、電壓轉換部16的 輸出電壓値爲零，比第2臨界値電壓低（步驟S3; NO)， DB電晶體2 1保持於ON，動力制動未被解除，回到步驟s】 ’電壓檢測部1 5檢測電壓。此外，第1臨界値比第2臨界値 小。 另一方面，爲了使馬達2驅動，馬達驅動裝置3開始輸 出電壓脈衝時，電壓檢測部1 5檢測馬達驅動裝置3的輸出 當作馬達2的端子間電壓，且頻率、電壓轉換部16的輸出 電壓値成爲第2臨界値電壓以上（步驟S7; YES)，控制 部18使制動部20的DB電晶體21爲OFF (步驟S8 ) 。DB電 晶體21成爲OFF，制動部20解除動力制動，從馬達驅動裝 置3對馬達2供給電力。此外，由於第2臨界値比第1臨界値 大’因此頻率、電壓轉換部1 6的電壓値成爲比第1臨界値 低’於施加有動力制動之狀態下，即使因爲某些原因，使 頻率、電壓轉換部16的電壓値成爲比第1臨界値大的情形 下’只要在第2臨界値以下則動力制動不會被解除。如此 地’藉由使第1臨界値和第2臨界値爲相異，且使第1臨界 値比第2臨界値小的方式，可使有關DB電晶體2 1的ON . 0 F F具有磁滯功能，而使動力制動安定地作用於馬達2。 以上，本實施形態係電壓檢測部1 5檢測馬達2的端子 -11 - 201223122 2a間的端子間電壓，頻率、電壓轉換部16將端子間電壓的 頻率轉換成電壓値予以輸出，且電壓比較部17和控制部18 和制動部20係根據比較頻率、電壓轉換部16的輸出電壓値 和預定臨界値電壓的結果而對馬達施加制動，藉此使馬達 制動裝置1 〇可判斷施加制動的時序而對馬達2施加制動。 又，馬達制動裝置1 〇即使沒有來自馬達驅動裝置3的伺服 ΟΝ/OFF等功能切換的時序之指導訊號，亦能利用簡易之 構成而自動地判斷功能切換。又，在馬達驅動裝置3内設 動力制動的電路之情形，由於需要切換電路等而產生功能 切換的時間耗損，但藉由本實施形態之馬達制動裝置1 〇， 由於不要切換電路而能達成減少時間耗損。 又，本實施形態可與馬達驅動裝置3分別構成，由於 不需要在馬達驅動裝置3預先設置専用埠，或爲了防止雜 音等造成的錯誤動作而連接屏蔽線，因此可達成馬達驅動 裝置3之小型化。 又，於伺服OFF之狀態下成爲無電力供給之後，根據 電壓比較部17的比較結果，電連接於馬達2的端子2a間之 DB電阻器22將馬達2的逆起電力轉換成熱能之情形下，馬 達制動裝置1 〇可對馬達2有效地施加動力制動。 又，制動部20根據電壓比較部17的比較結果，藉由電 晶體元件之DB電晶體21，使DB電阻器22電連接於馬達2的 端子間之情形下，比繼電器等之回應速度快，可迅速地對 馬達2施加動力制動。 馬達制動裝置10具備：輸入端子11，用以連接使馬達 -12- 201223122 2驅動的馬達驅動裝置3之輸出；輸出端子12，用以連接馬 達2的端子；及導線13，用以連接輸入端子11和輸出端子 1 2 ;於電壓檢測部1 5檢測導線1 3的電壓之情形，即使與馬 達驅動裝置3分別構成（任選），仍可將馬達制動裝置1 〇 設置在馬達2和馬達驅動裝置3之間，由於不需要設置専用 埠用以接收來自驅動馬達2的馬達驅動裝置3之指導訊號， 或爲了防止雜音等造成的錯誤動作而連接屏蔽線，因此可 使馬達制動裝置10精簡化，達成馬達制動裝置10降低成本 〇 此外，本發明並非限定於上述各實施形態者。上述各 實施形態爲例示，與本發明之申請專利範圍記載的技術思 想具有實質上相同的構成且達成同樣作用效果者，皆包含 在本發明之技術範圍。 【圖式簡單說明】 圖1係顯示關於本發明之實施形態之馬達控制系統的 槪略構成之一例的方塊圖。 圖2係顯示圖1之馬達制動裝置的動作例之流程圖。 圖3係顯示圖1之馬達的端子間之電壓的時間性變化之 一例的線圖。 圖4係顯不圖1之馬達制動裝置的動作例之流程圖。 【主要元件符號說明】 2 :馬達 -13- 201223122 2 a :端子 3 :馬達驅動裝置 1 0 :馬達制動裝置 1 1 :輸入端子 12 :輸出端子 1 3 :導線 1 5 :電壓檢測部 16:頻率、電壓轉換部 1 7 :電壓比較部 2 0 :制動部 21 : DB電阻器（電阻器） 22 : DB電晶體（電晶體元件） -14-201223122 SUMMARY OF THE INVENTION [Technical Field] The present invention relates to a motor brake device and a motor control method, and more particularly to a motor brake device and a motor control method using dynamic brake. [Prior Art] The dynamic brake that acts when the motor is actuated is used for braking of railway vehicles and the like, and various improvements have been made. For example, Patent Document 1 proposes a dynamic braking method for controlling a driving motor, which is a method of simultaneously triggering a ratio of a power transistor upper side or a lower side transistor of a driving motor when the main circuit is blocked or the like is stopped. Change in the middle and make it slow down with the mechanical stop. [PRIOR ART DOCUMENT] [Patent Document 1] [Patent Document 1] JP-A-2007-3 73 8 2 SUMMARY OF THE INVENTION [Problems to be Solved by the Invention] However, a conventional dynamic brake circuit or motor for dynamic braking The control device usually obtains the timing of applying the brake to the motor by the command signal from the external controller. Therefore, in the case of selecting the external power brake device, it is necessary to have a dedicated signal line for guiding the timing. The present invention has been made in order to solve the above problems, and a problem is that -5-201223122 provides a motor brake device and a motor control method for determining the timing of applying a brake and applying a brake to the motor. [Means for Solving the Problem] In order to solve the above problems, the present invention provides a voltage detecting unit for detecting a voltage between terminals of a motor; and a frequency and voltage converting unit for converting a frequency of the voltage between the terminals The voltage 値 is outputted; the voltage comparison unit compares the voltage 输出 outputted from the frequency and voltage conversion unit with a predetermined threshold 値 voltage; and the braking unit applies braking to the motor based on a comparison result of the voltage comparison unit. [Effect of the Invention] The present invention detects the voltage between the terminals of the motor, converts the frequency of the voltage between the terminals into a voltage 値, and outputs a result based on comparing the output voltage 値 with a predetermined threshold 値 voltage. The motor applies a brake, and provides a motor brake device and a motor control method for judging the timing of applying the brake to apply a brake to the motor. [Embodiment] First, the configuration and main functions of a motor control system according to an embodiment of the present invention will be described with reference to Fig. 1 . Fig. 1 is a block diagram showing an example of a schematic configuration of a motor control system according to an embodiment of the present invention. As shown in FIG. 1, the motor control system 1 includes a motor 2 that is driven by a three-phase AC -6 - 201223122, a motor drive device 3 that supplies electric power for actuating the motor 2, and a motor brake that applies a brake to the motor 2. Device 10. The motor 2 has a terminal 2a for receiving power supply from the motor driving device 3. The motor 2 is a linear motor or a rotary motor having a stator and a movable member (or a rotator) that move relative to each other by magnetic action, and is formed of a coil or a permanent magnet. This coil is connected to the terminal 2a. Further, the motor 2 series servo motor has a sensor (not shown) for detecting the state of the motor 2, and the sensor is connected to the motor driving device 3. The motor drive device 3 has an output terminal 3a for supplying electric power to the motor, and converts electric power supplied from the power supply device into three-phase alternating current, and supplies electric power to the motor 2 via the motor brake device 10. The output terminal 3a is formed by terminals for U phase, V phase, and W phase. Further, the motor drive device 3 is controlled by a higher-level controller (not shown), and the motor 2 is set to the servo-on state in response to an instruction from the host controller, and the motor 2 is supplied with electric power or set to the servo OFF state to stop. Power supply. The motor brake device 10 has: an input terminal 11 for connecting the output of the motor drive device 3; an output terminal 12 for connecting the terminal of the motor; and a wire 13 for connecting the input terminal 1 1 and the output terminal 12; a voltage detecting unit 15 for detecting a voltage between terminals between the terminals 2a of the motor 2; a frequency for converting the frequency of the voltage between the terminals into a voltage 、, and a voltage conversion (F/V) unit 16; comparing the frequency, a voltage comparison unit 17 that outputs a voltage 値 and a predetermined threshold voltage, a control unit 18 that controls the braking of the motor 2 based on the comparison result of the voltage comparison unit 17, and a control unit 18 according to the control unit 18 A brake portion 20 to which the motor 2 is applied is applied. 201223122 The input terminal 11 is connected to each of the output terminals 3a of the motor drive unit 3 for receiving electric power supplied to the motor 2. The output terminal 12 is connected to each terminal 2a of the motor 2 for supplying electric power from the motor drive unit 3 to the motor 2. The wire 13 has a ϋ phase wire 1 3 u, a V phase wire 1 3 v, and a W phase wire 13w. The U-phase wire 13u and the V-phase wire 13v are connected to the voltage detecting portion 15. Further, the voltage detecting unit 15 is preferably connected to any one of the U-phase wire 13u, the V-phase wire 13ν, and the W-phase wire 13w. Further, the U-phase wire 13u, the V-phase wire 13v, and the W-phase wire 13w are connected to the braking portion 20, and when the power is actuated, the reverse power generated by the motor 2 is consumed by the braking portion 20. The voltage detecting unit 15 detects the voltage between the wires 13 and outputs it to the frequency and voltage converting unit 16. The frequency and voltage converting unit 16 has an F/V converter for converting the pulse frequency of the voltage detected by the voltage detecting unit 15 into a voltage 配合 which is matched with the pulse frequency. The voltage comparing unit 17 has a comparator for outputting a comparison frequency, an output voltage 値 of the voltage converting unit 16, and a comparison result between the first critical enthalpy and the second critical enthalpy. When the control unit 18 is below the first threshold ,, the switch that turns the brake operation of the brake unit 20 is turned ON is turned on, and when the second threshold 値 or higher, the switch that outputs the brake action of the brake unit 20 is output. OFF (disconnected) signal. The brake unit 20 includes a power brake transistor (DB transistor) 21 as an example of a transistor element, and a dynamic brake resistor (DB resistor) 22, which is an example of a 201223122 resistor, and causes the reverse power generated in the motor 2. Converted into thermal energy; and the rectifier circuit 23 rectifies the reverse power generated by the motor 2 by the rectifying diode. Next, the operation of the motor control system 1 will be described with reference to Figs. 2 to 4 . Fig. 2 is a flow chart showing an example of the operation of the dynamic brake of the motor brake device 10. Fig. 3 is a line diagram showing an example of a temporal change in voltage between terminals of the motor 2. Fig. 4 is a flow chart showing an example of the operation of releasing the brake of the motor brake device 10. First, an operation when the motor brake device 10 applies power to the motor 2 will be described. As shown in Fig. 2, the voltage detecting unit 15 detects the voltage between the terminals of the motor 2 (step S1). Specifically, the voltage detecting unit 15 detects the voltage between the wires 1 3 to which the terminal 2a of the motor 2 is connected, and outputs the detected voltage to the frequency and voltage converting unit 16. As shown in FIG. 3, the motor drive device 3 outputs a voltage pulse of a certain frequency in a state where the servo is ON. This voltage pulse cooperates with the frequency of the current flowing through the motor 2 to reverse the positive and negative voltages. Further, the frequency of the voltage pulse is higher than the frequency of the current flowing through the motor 2, that is, higher than the frequency at which the motor 2 rotates. Next, the frequency and voltage converting unit 16 converts the frequency of the voltage detected by the voltage detecting unit 15 into a voltage 配合 of the matching frequency (step S2). Specifically, the frequency and voltage converting unit 16 converts the frequency of the voltage pulse into a voltage 配合 that matches the frequency of the voltage pulse. The higher the frequency, the voltage conversion unit 丨6 is, the higher the voltage 输出 is output. -9 - 201223122 Next, the voltage comparison unit 17 determines whether or not the output voltage 値 of the frequency and voltage conversion unit 16 is equal to or lower than the first threshold voltage (step S3). As shown in FIG. 3, the motor drive device 3 outputs a high-frequency voltage pulse in the state of the servo ON. Therefore, the output voltage 値 of the frequency and voltage conversion unit 16 is higher than the first threshold voltage (step S3; NO), Returning to step S1, the voltage detecting unit 15 detects the voltage. On the other hand, when the servo is turned OFF, the motor drive unit 3 stops the output of the voltage pulse. When the output of the voltage pulse is stopped, as shown in Fig. 3, a voltage waveform corresponding to the reverse power of the rotation of the motor 2 occurs between the terminals of the motor 2. In this case, since the frequency of the rotation is lower than the frequency of the voltage pulse, the output voltage 値 of the frequency and voltage conversion unit 16 becomes equal to or lower than the first threshold voltage (step S3; YES), and the control unit 18 sets the DB of the braking unit 20. The transistor 21 is ON (step S4). Once the DB transistor 21 is turned ON, the current generated by the reverse power of the motor 2 flows through the DB resistor 22 and is converted into heat, causing the braking portion 20 to apply dynamic braking to the motor 2. Next, the operation of the brake release of the motor brake device 10 will be described. This is an operation when the motor 2 is driven or the brake is not released. As shown in Fig. 4, the voltage detecting unit 15 detects the voltage between the terminals of the motor 2 (step S5). Similarly to the step S1, for example, when the motor 2 is stopped, the voltage between the terminals of the motor 2 is zero when the electric power is not supplied from the motor driving device 3. Next, the frequency and voltage conversion unit 16 converts the frequency of the voltage detected by the voltage detecting unit 15 into a voltage 配合 of the matching frequency (step S6). For example, when the voltage between the terminals of the motor 2 is zero, the voltage -10-201223122 cannot be detected and the frequency is zero, and the output voltage 値 of the frequency and voltage conversion unit 16 becomes zero. Then, the voltage comparison unit 17 determines the frequency and voltage conversion unit. Whether the output voltage 16 of 16 is equal to or higher than the second critical threshold voltage (step S7). For example, when the voltage between the terminals of the motor 2 is zero, the output voltage 値 of the frequency and voltage conversion unit 16 is zero, and is lower than the second critical threshold voltage (step S3; NO), and the DB transistor 2 1 is kept ON. The dynamic brake is not released, and the process returns to step s]. The voltage detecting unit 15 detects the voltage. Further, the first critical enthalpy is smaller than the second critical enthalpy. On the other hand, when the motor drive device 3 starts to output a voltage pulse, the voltage detecting unit 15 detects that the output of the motor drive device 3 is the voltage between the terminals of the motor 2, and the output of the frequency and voltage conversion unit 16 is output. When the voltage 値 becomes equal to or higher than the second critical 値 voltage (step S7; YES), the control unit 18 turns off the DB transistor 21 of the braking unit 20 (step S8). The DB transistor 21 is turned OFF, the brake unit 20 releases the dynamic brake, and the motor 2 is supplied with electric power from the motor drive unit 3. In addition, since the second critical enthalpy is larger than the first critical enthalpy, the frequency 、 of the voltage and voltage converting unit 16 is lower than the first critical enthalpy ′ in a state where dynamic braking is applied, even for some reason, the frequency is made. When the voltage 値 of the voltage conversion unit 16 is larger than the first critical ', the dynamic brake is not released as long as it is below the second critical 。. Thus, by making the first critical enthalpy and the second critical enthalpy different, and making the first critical enthalpy smaller than the second critical enthalpy, the ON of the DB transistor 2 1 can have hysteresis. The function is such that the dynamic brake acts on the motor 2 in a stable manner. As described above, in the present embodiment, the voltage detecting unit 15 detects the voltage between the terminals between the terminals -11 - 201223122 2a of the motor 2, and the frequency and voltage converting unit 16 converts the frequency of the voltage between the terminals into a voltage 値, and outputs the voltage comparing unit. 17 and the control unit 18 and the braking unit 20 apply braking to the motor based on the comparison frequency, the output voltage 电压 of the voltage converting unit 16 and the predetermined threshold 値 voltage, thereby causing the motor brake device 1 to determine the timing of applying the brake. A brake is applied to the motor 2. Further, the motor brake device 1 can automatically determine the function switching by a simple configuration without the guidance signal of the timing of switching the functions such as the servo ΟΝ/OFF of the motor drive device 3. Further, in the case where a circuit for dynamic braking is provided in the motor drive unit 3, it is necessary to switch the circuit or the like to cause time loss of function switching. However, with the motor brake device 1 of the present embodiment, it is possible to reduce the time by not switching the circuit. Loss. Further, the present embodiment can be configured separately from the motor drive device 3, and it is not necessary to provide the motor drive device 3 with a preset cymbal, or to connect a shield wire in order to prevent an erroneous operation due to noise or the like, thereby achieving a small size of the motor drive device 3. Chemical. Further, after the power supply is turned off in the state of the servo OFF, the DB resistor 22 electrically connected between the terminals 2a of the motor 2 converts the reverse power of the motor 2 into heat energy based on the comparison result of the voltage comparison unit 17. The motor brake device 1 有效 can effectively apply dynamic braking to the motor 2 . Further, in the case where the DB resistor 22 is electrically connected to the terminals of the motor 2 by the DB transistor 21 of the transistor element, the braking unit 20 is faster than the response speed of the relay or the like according to the comparison result of the voltage comparing unit 17. Dynamic braking can be applied to the motor 2 quickly. The motor brake device 10 includes an input terminal 11 for connecting an output of a motor driving device 3 for driving a motor -12-201223122 2, an output terminal 12 for connecting a terminal of the motor 2, and a lead 13 for connecting the input terminal 11 and the output terminal 1 2; in the case where the voltage detecting portion 15 detects the voltage of the wire 13 , even if it is configured separately from the motor driving device 3 (optional), the motor braking device 1 can be set to the motor 2 and the motor drive Between the devices 3, since it is not necessary to provide a guide signal for receiving the motor drive device 3 from the drive motor 2, or to connect the shield wire in order to prevent malfunction caused by noise or the like, the motor brake device 10 can be simplified. The motor brake device 10 is reduced in cost, and the present invention is not limited to the above embodiments. Each of the above-described embodiments is exemplified, and is substantially the same as the technical idea described in the claims of the present invention, and the same effects are achieved, and are included in the technical scope of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a block diagram showing an example of a schematic configuration of a motor control system according to an embodiment of the present invention. Fig. 2 is a flow chart showing an operation example of the motor brake device of Fig. 1. Fig. 3 is a line diagram showing an example of temporal changes in voltage between terminals of the motor of Fig. 1. Fig. 4 is a flow chart showing an operation example of the motor brake device of Fig. 1. [Main component symbol description] 2 : Motor-13- 201223122 2 a : Terminal 3 : Motor drive unit 1 0 : Motor brake device 1 1 : Input terminal 12 : Output terminal 1 3 : Wire 1 5 : Voltage detection unit 16: Frequency Voltage conversion unit 1 7 : Voltage comparison unit 2 0 : Brake unit 21 : DB resistor (resistor) 22 : DB transistor (transistor element) -14-