Machine tool and machine tool door control method

Abstract

To provide a machine tool capable of opening the door of the machine tool without operating an operating device. [Solution] The machine tool includes a door and a servo system that controls the opening and closing of the door. The servo system includes a servo motor with a rotary shaft that opens and closes the door by rotating the rotary shaft, a servo driver that operates the servo motor, and a controller connected to the servo driver. When an external force is applied to the door in a direction that opens the door while the door is maintained in a closed position by the servo system, the servo driver or controller detects the torque acting on the rotary shaft due to the external force. The controller sends a command to the servo driver to rotate the servo motor in the direction that opens the door, provided that the torque is equal to or greater than a predetermined threshold.

Description

[Technical Field]

[0001] The present disclosure relates to a machine tool and a door control method for the machine tool. [Background technology]

[0002] Conventionally, machine tools that use a motor to open and close a door to a processing area have been known. As an example of such a machine tool, Japanese Patent No. 7442704 (Patent Document 1) discloses a machine tool that detects abnormalities in the opening and closing operation of the door based on the torque waveform of a servo motor. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 7442704 [Patent Document 2] Japanese Patent Application Laid-Open No. 2005-320788 Summary of the Invention [Problem to be solved by the invention]

[0004] The door of the machine tool disclosed in Patent Document 1 is maintained in its position by a servo lock function, and the door cannot be opened by hand when closed. To open the door of the machine tool, the operator must operate an operating device such as a control panel.

[0005] The present disclosure provides a machine tool and a machine tool door control method that enable the door of the machine tool to be opened without operating an operating device. [Means for solving the problem]

[0006] According to one aspect of the present disclosure, a machine tool includes a door and a servo system that controls opening and closing of the door. The servo system includes a servo motor having a rotary shaft and opening and closing the door by rotating the rotary shaft, a servo driver that operates the servo motor, and a controller connected to the servo driver. When an external force is applied to the door in a direction that opens the door while the door is maintained in a closed position by the servo system, the servo driver or the controller detects the torque acting on the rotary shaft due to the external force. The controller sends a command to the servo driver to rotate the servo motor in a direction that opens the door, provided that the torque is equal to or greater than a predetermined threshold.

[0007] According to another aspect of the present disclosure, a door control method for a machine tool includes the steps of: a servo system having a servo motor, a servo amplifier, and a controller, and controlling the opening and closing of a door of the machine tool, maintaining the door in a closed position; when an external force is applied to the door in a direction to open the door while the door is maintained in the closed position, a servo driver or a controller detecting the torque acting on the servo motor due to the external force; and, on condition that the torque is equal to or greater than a predetermined threshold, the controller sending a command to the servo driver to rotate the servo motor in a direction to open the door. [Effects of the Invention]

[0008] According to the present disclosure, it is possible to open the door of a machine tool without operating an operating device. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. [Figure 2] 10A and 10B are diagrams illustrating opening and closing of the left door based on the operation of the operating device. [Figure 3] FIG. 10 is a diagram showing the left and right doors fully open. [Figure 4] FIG. 10 is a diagram showing a state in which an operator is applying an external force in the opening direction to the left door in the closed state. [Figure 5] 5 is a diagram for explaining the operation of the servo system when the external force shown in FIG. 4 is applied to the left door. FIG. [Figure 6] FIG. 10 is a diagram showing a setting screen provided by the operation device. [Figure 7] FIG. 10 is a flowchart showing the process flow when an operator uses the push-open function to open the left door. [Figure 8] FIG. 1 is a perspective view of a machine tool of a different type from the machine tool. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the following description, the same parts and components are denoted by the same reference numerals. Their names and functions are also the same. Therefore, detailed description thereof will not be repeated.

[0011] 1 is a perspective view of a machine tool according to the present embodiment. As shown in FIG. 1, the machine tool 1 includes a main body 10, a door 20, and an operating device 30.

[0012] In this example, a 5-axis multi-tasking machine is used as the machine tool 1, but the present invention is not limited to this. The machine tool 1 may also be, for example, another multi-tasking machine such as a 4-axis multi-tasking machine, a horizontal machining center, a turning center, a lathe, etc. The machine tool 1 is preferably a large machine tool. An example of such a large machine tool is a machine tool having a pair of workpiece spindles that hold a long workpiece from both ends (left and right when viewed from the front of the machine tool 1).

[0013] The door section 20 covers the opening of the main body section 10. The door section 20 includes a door 21 (hereinafter also referred to as the "left door 21") located on the left side when viewed from the front of the machine tool 1, and a door 22 (hereinafter also referred to as the "right door 22") located on the right side. The left door 21 and the right door 22 are sliding doors.

[0014] The left door 21 has a window 211 and a handle 212. The right door 22 has a window 221 and a handle 222. The handle 212 is provided on the right door 22 side in the Z-axis (horizontal) direction. The handle 222 is provided on the left door 21 side in the Z-axis direction. The handles 212, 222 extend in the X-axis (vertical) direction.

[0015] In the state shown in FIG. 1, the left door 21 and the right door 22 are closed. The ends of the left door 21 and the right door 22 are in contact with each other. The left door 21 and the right door 22 are movable in the Z-axis direction. When the left door 21 slides in the negative direction of the Z-axis from the state shown in FIG. 1, it enters an open state. Similarly, when the right door 22 slides in the positive direction of the Z-axis from the state shown in FIG. 1, it enters an open state.

[0016] The operating device 30 includes an upper housing 31, a lower housing 32, and a hinge unit 33. The upper housing 31 is connected to the lower housing 32 by the hinge unit 33. The position of the upper housing 31 can be changed by the hinge unit 33. The operating device 30 is attached to the main body unit 10. The operating device 30 is communicatively connected to a control panel (not shown) of the main body unit 10.

[0017] 2 is a diagram illustrating the opening and closing of the left door 21 based on the operation of the operating device 30. As shown in FIG. 2, the machine tool 1 further includes, in addition to the left door 21 and the operating device 30, a drive unit 40, gears 51 and 52, a servo motor 60, a servo driver 70, a motion controller 80, a numerical control (NC) 91, and a programmable logic controller (PLC) 92. The servo motor 60 has a main body 61, a rotation shaft 62, and an encoder 63. The motion controller 80 includes the servo controller 81. The servo driver is also referred to as a servo amplifier.

[0018] The servo motor 60 is connected to a servo driver 70. The servo driver 70 is connected to a motion controller 80 so as to be able to communicate with it. More specifically, the servo driver 70 is connected to a servo controller 81 so as to be able to communicate with it. Similarly, the operation device 30, the numerical control device 91, and the PLC 92 are also connected to the motion controller 80 so as to be able to communicate with it.

[0019] The drive unit 40 opens and closes the left door 21. The drive unit 40 has a pair of pulleys 41 and 42 and an endless belt 43. The belt 43 is tensioned by the pulleys 41 and 42. The left door 21 is fixed to the belt 43 by a connecting member (not shown).

[0020] Specifically, pulley 41 and pulley 42 are spaced apart in the Z-axis direction (FIG. 1). In this example, pulley 41 is a driving pulley. Pulley 42 is a driven pulley. Pulley 41 is rotatable around shaft 419. Pulley 42 is rotatable around shaft 429. Shafts 419 and 429 extend in the X-axis direction.

[0021] The gear 51 is fixed to the shaft 419. The gear 51 is rotatable around the shaft 419. The rotation of the gear 51 causes the pulley 41 to rotate. The gear 52 is engaged with the gear 51. The gear 52 is fixed to a rotating shaft 62. The rotation of the rotating shaft 62 causes the gear 52 to rotate. The number of teeth of the gear 51 is greater than the number of teeth of the gear 52. Therefore, the rotation speed of the gear 51 is slower than the rotation speed of the gear 52.

[0022] When the operation device 30 receives an operator operation to transition the left door 21 to an open state while the left door 21 is in a closed state, the operation device 30 sends a command to open the door to the motion controller 80. Upon receiving the command, the motion controller 80 sends a command signal to the servo driver 70. More specifically, the servo controller 81 in the motion controller 80 sends target values ​​for the rotational position, rotational speed, and torque to the servo driver 70.

[0023] The servo driver 70 supplies the servo motor 60 with the power required for the servo motor 60 to rotate according to the target value. The encoder 63 of the servo motor 60 detects the actual rotational position and rotational speed of the servo motor 60 and returns the detection result as a feedback signal to the servo driver 70. The servo driver 70 performs feedback control based on the target value and the feedback signal.

[0024] When power is supplied to the servo motor 60, the rotary shaft 62 rotates in a direction to open the left door 21. The rotation of the rotary shaft 62 rotates the gear 52. The rotation of the gear 52 rotates the gear 51. The rotation of the gear 51 drives the pulley 41. The drive of the pulley 41 drives the belt 43. The drive of the belt 43 drives the pulley 42. The drive of the belt 43 causes the left door 21 to start moving in the opening direction. In this example, the left door 21 moves to the open position (in this example, the fully open position).

[0025] On the other hand, when the operation device 30 receives an operator operation to transition the left door 21 to a closed state while the left door 21 is in an open state, the operation device 30 sends a command to close the door to the motion controller 80. In this case, the rotary shaft 62 rotates in a direction to close the left door 21. As a result, the left door 21 moves to the closed position.

[0026] In this way, the operator can open and close the left door 21 using the operating device 30. While the above has described the opening and closing of the left door 21, the right door 22 can also be opened and closed by a servo motor and a servo driver (not shown) connected to the servo controller 81. The operator can open and close the right door 22 using the operating device 30.

[0027] The motion controller 80 also sends commands to the numerical control device 91 and the PLC 92.

[0028] Hereinafter, the servo motor 60, the servo driver 70, the servo motor (not shown) for the right door 22, the servo driver (not shown) for the right door 22, and the servo controller 81 will be collectively referred to as the "servo system SYS."

[0029] The servo system SYS has a control function (also referred to as a "servo lock function") that holds the position of the rotary shaft 62 so that it does not rotate in response to an external force while the servo motor 60 is stopped. By using the servo lock function, the left door 21 is maintained in the closed position, for example, as shown in FIG. 1. Similarly, the right door 22 is also maintained in the closed position, as shown in FIG. 1. This function is realized by the servo controller 81 inputting a torque target value into the torque control loop of the servo driver 70.

[0030] Figure 3 is a diagram showing the left door 21 and the right door 22 in a fully open state. As shown in Figure 3, the machine tool 1 has a machining area 100 where a workpiece is machined. A tool spindle 110 is installed in the machining area 100. The left door 21 and the right door 22 separate the machining area 100 from the space outside the machine tool 1. The left door 21 and the right door 22 define the machining area 100. The left door 21 and the right door 22 are front doors for entering and exiting the workpiece.

[0031] 4 is a diagram showing a state in which an operator applies an external force in the negative direction of the Z axis to the closed left door 21. As described above, the left door 21 is maintained in the closed position by the servo lock function.

[0032] 4, the operator stands in front of the right door 22 and applies an external force to the left door 21 by pushing the handle 212 of the left door 21 in the negative direction of the Z axis (the direction of arrow A). In this example, the operator pushes the handle 212 while gripping the handle 212. Note that the method of applying the external force is not limited to this. For example, the operator may stand in front of the left door 21, grip the handle 212 of the left door 21 with, for example, his right hand, and pull it in the negative direction of the Z axis to apply an external force.

[0033] 5 is a diagram for explaining the operation of the servo system SYS when the external force shown in FIG. 4 is applied to the left door 21. When an external force in the direction of arrow A is applied to the left door 21 as shown in FIG. 5, a torque (N·m) is applied to the rotating shaft 62 of the servo motor 60 via gears 51 and 52. More specifically, a torque that tries to rotate the rotating shaft 62 in a direction to open the left door 21 acts on the rotating shaft 62. Note that the gears 51 and 52 do not have to mesh directly with each other, and one or more other gears may be present between the gears 51 and 52.

[0034] The servo driver 70 detects the external force (load) applied to the left door 21 as torque. More specifically, the servo driver 70 detects the torque acting on the rotary shaft 62 of the servo motor 60 due to the external force applied to the left door 21 in the direction to open the left door 21. In this example, the servo driver 70 detects the torque based on the current value of the current flowing through the servo motor 60 and the voltage value applied to the servo motor 60 when the external force is applied. Specifically, the servo driver 70 calculates the power (P) from the current value (I) and voltage value (V), and calculates the torque (T) by dividing the power P by 2πω, where ω is the angular velocity of the rotor. The servo driver 70 notifies the servo controller 81 of the detected torque.

[0035] The servo controller 81 determines whether the torque detected by the servo driver 70 (i.e., the torque acting on the rotary shaft 62 due to the above-mentioned external force) exceeds a predetermined threshold value Th. If the torque is equal to or greater than the threshold value Th, the servo controller 81 rotates the servo motor 60 in a direction to open the left door 21. More specifically, the servo controller 81 rotates the rotary shaft 62 of the servo motor 60 by sending an open command (specifically, the above-mentioned target value) to the servo driver 70.

[0036] As described above, the operator can automatically transition the left door 21 from the closed state to the open state by applying an external force of a certain level or more to the left door 21 in the direction of arrow A. The operator can open the left door 21 simply by applying an external force of a certain level or more to the left door 21 in the opening direction.

[0037] Therefore, the operator does not need to operate the operating device 30 to open the left door 21. The operator can open the left door 21 without moving to the front of the operating device 30. In the large machine tool 1 shown in FIG. 1 etc., the operator can significantly reduce the distance he or she must travel to open the left door 21. In this way, the machine tool 1 has excellent work efficiency.

[0038] Furthermore, the machine tool 1 realizes the automatic opening operation of the left door 21 based on the above-mentioned external force by utilizing the function of the servo motor 60, which opens and closes the left door 21 based on commands from the operating device 30. Therefore, no parts such as dedicated buttons or sensors are required to realize the automatic opening operation of the left door 21 based on external force. Therefore, the machine tool 1 is superior in terms of cost compared to machine tools that require such parts.

[0039] In this example, threshold value Th is set as a default value so that the left door 21 will automatically open when an external force of 250 N is applied to the left door 21 in the direction of arrow A. Threshold value Th is set taking into consideration the reduction ratio of gear 51 and gear 52. Therefore, threshold value Th is set individually depending on the type of machine tool 1 (more specifically, gear configuration).

[0040] Although the above description has been given using the left door 21 as an example, the right door 22 also has a similar function. That is, the operator can automatically transition the right door 22 from a closed state to an open state by applying an external force of a certain level or more to the right door 22 in the direction opposite to arrow A. The operator can open the right door 22 simply by applying an external force of a certain level or more to the right door 22 in the opening direction.

[0041] As described above, in the machine tool 1, the left door 21 and the right door 22 can be automatically opened simply by applying an external force of a certain level or more in an opening direction to the closed left door 21 and the right door 22. On the other hand, even if an external force of a certain level or more is applied in a closing direction to the open left door 21 and the right door 22, the left door 21 and the right door 22 will not automatically close. With this configuration, it is possible to satisfy the standards imposed on machine tools.

[0042] In the following, it is assumed that the operator presses the handles 212, 222 when opening the left door 21 and the right door 22, and for convenience, the function of automatically opening the left door 21 and the right door 22 without operating the operating device 30 as described above will also be referred to as the "push-open function."

[0043] FIG. 6 is a diagram showing a setting screen (UI: User Interface) provided by the operation device 30. As shown in FIG. 6, the upper housing 31 has a touch screen 310. The touch screen 310 has a display 311 and a touch panel 312. The touch panel 312 is superimposed on the display 311. The lower housing 32 has an input device 320. The input device 320 has a plurality of operation keys 321. In this example, each operation key 321 is a physical key.

[0044] When a predetermined operation is received, the operation device 30 displays a setting screen 310G for the push-to-open function. The setting screen 310G includes an image object 3110 and an image object 3120.

[0045] The image object 3110 includes a toggle button 3111 for turning the push-open function on and off, and a slider 3112 for changing the magnitude of the external force required to open the left door 21 and the right door 22 .

[0046] 6, the toggle button 3111 is in the ON position. When the operator slides the toggle button 3111 from the ON position to the OFF position, the machine tool 1 changes the push-open function to OFF. When the push-open function is changed to OFF, the servo controller 81 does not send a command (target value) to the servo driver 70 to open the left door 21, even if an external force of a certain level or more is applied to the left door 21 in the opening direction, for example.

[0047] This configuration satisfies the needs of operators who do not consider the push-open function necessary.

[0048] The operator can change the above-mentioned threshold value Th from the above-mentioned default value by operating the slider 3112. The slider 3112 is an image showing multiple levels of the threshold value Th. The operator can select one level from multiple levels (five in this example) ranging from High level to Low level by moving the knob 3112a of the slider 3112 left and right. The operation device 30 accepts this operation.

[0049] In this example, the threshold value Th can be set from among 80% of the default value, 90% of the default value, the default value, 110% of the default value, and 120% of the default value. In this case, the external forces in the Z-axis direction required to open the left door 21 and the right door 22 are 200 N, 225 N, 250 N, 275 N, and 300 N, respectively.

[0050] According to this configuration, the threshold value Th can be set according to the operator. Typically, an appropriate threshold value Th can be set according to the physique of the operator.

[0051] The image object 3120 includes a toggle button 3121 that turns on and off a function that stops the left door 21 and the right door 22 at an intermediate position when the push-open function is executed (hereinafter also referred to as an "intermediate position stop function"). In this example, as shown in Fig. 6, the toggle button 3121 is in the OFF position by default.

[0052] The image object 3120 further includes an input field 3122 for inputting the position at which the left door 21 and the right door 22 should stop when the operator turns on the intermediate position stop function. In this example, 615 mm indicates the fully open state. The image object 3120 further includes a button 3123 for confirming the value input in the input field 3122.

[0053] The image object 3120 further includes a button 3124 for setting the intermediate position by teaching. When the button 3124 is selected, the screen displayed on the touch screen 310 changes from the setting screen 310G to another setting screen, and the servo lock function is stopped. In this state, if the operator opens the left door 21 or the right door 22 to a desired position and performs a predetermined operation on the setting screen after the change, the open position can be set as the intermediate position.

[0054] With this configuration, the left door 21 and the right door 22 can be opened to a position desired by the operator by using the push-open function.

[0055] In the above description, an example has been given in which the push-open function and the intermediate position stop function are common to the left door 21 and the right door 22, but the present invention is not limited to this. The setting screen 310G of the operating device 30 may be configured so that the push-open function and the intermediate position stop function can be set individually for the left door 21 and the right door 22.

[0056] The touch panel 312 and the input device 320 correspond to the "input device" of the present disclosure.

[0057] FIG. 7 is a flow chart showing the flow of processing when an operator opens the left door 21 using the push-open function.

[0058] 7, the servo system SYS maintains the left door 21 in the closed position by the servo lock function (step S1). When an external force is applied to the left door 21 in a direction to open the left door 21, the servo motor 60 detects the torque acting on the rotary shaft 62 based on the external force (step S2).

[0059] The servo controller 81 determines whether the detected torque is equal to or greater than the threshold value Th (step S3). If the torque is equal to or greater than the threshold value Th (YES in step S3), the servo controller sends a command to the servo driver 70 to rotate the servo motor 60 in a direction to open the left door 21 (step S4). If the torque is less than the threshold value Th (NO in step S3), the servo driver 70 returns the process to step S2.

[0060] The process flow shown in FIG. 7 is the same when the right door 22 is opened using the push-open function.

[0061] <Summary> For the sake of convenience, the machine tool 1 will be summarized as follows, focusing on the left door 21 of the left door 21 and the right door 22. The same applies to the right door 22.

[0062] (1) The machine tool 1 includes a left door 21 and a servo system SYS that controls the opening and closing of the left door 21. The servo system SYS includes a servo motor 60 that has a rotary shaft 62 and opens and closes the doors 21, 22 by rotation of the rotary shaft 62, a servo driver 70 that operates the servo motor 60, and a servo controller 81 connected to the servo driver 70.

[0063] When an external force is applied to the left door 21 in a direction to open the left door 21 while the servo system SYS keeps the left door 21 in the closed position, the servo driver 70 detects the torque acting on the rotary shaft 62 due to the external force. The servo controller 81 sends a command to the servo driver 70 to rotate the servo motor 60 in a direction to open the left door 21, provided that the torque is equal to or greater than a threshold value Th.

[0064] With this configuration, the left door 21 can be opened without operating the operating device 30.

[0065] (2) Machine tool 1 further includes operating device 30 communicably connected to servo controller 81. Operating device 30 accepts an operator operation (first operation) to change threshold value Th. With this configuration, threshold value Th can be set according to the operator.

[0066] (3) The operation device 30 has a display 311 that displays an image object 3110 (FIG. 6) that indicates multiple levels of the threshold value Th, and a touch panel 312 that accepts an operation by the operator to select one level from multiple levels (five in this example). With this configuration, the operator can easily change the threshold value Th.

[0067] (4) When the operating device 30 receives another operator operation (second operation), the servo controller 81 stops the function of sending a command to the servo driver 70 on the condition that the torque is equal to or greater than the threshold value Th. Specifically, the push-open function is stopped. This configuration can satisfy the needs of operators who do not consider the push-open function necessary.

[0068] (5) The above command is a command to move the left door 21 to a predetermined position. With this configuration, the operator can move the left door 21 in the closed state to a predetermined position by applying an external force to the left door 21 so that a torque equal to or greater than the threshold value Th acts on the rotation shaft 62.

[0069] (6) The specified position is a position where the left door 21 is fully open. With this configuration, the operator can move the left door 21 from a closed state to the fully open position by applying an external force to the left door 21 so that a torque equal to or greater than the threshold value Th acts on the rotation shaft 62.

[0070] (7) The machine tool 1 further includes a processing area 100 where a workpiece is processed. The left door 21 is a sliding door that separates the processing area 100 from the space outside the machine tool 1. This configuration allows easy access to the processing area 100.

[0071] (8) When the left door 21 is maintained in an open position by the servo system SYS, if an external force is applied to the left door 21 in a direction to close the left door 21 (the positive direction of the Z axis in Figure 3), the servo controller 81 will maintain the left door 21 in an open position even if the torque acting on the rotation shaft 62 due to the external force in the direction to close the left door 21 exceeds the threshold value Th.

[0072] With this configuration, as described above, even if an external force of a certain magnitude or more is applied to the left door 21 in the closing direction while it is in the open state, the left door 21 will not close automatically. In other words, the servo system SYS does not have a "push-to-close" function. Therefore, it is possible to meet the standards imposed on machine tools.

[0073] <Modification> (1) First Modification Figure 8 is a perspective view of a machine tool of a different type from machine tool 1. As shown in Figure 8, machine tool 1A includes a main body 10A, a door 20A, and an operating device 30A. Machine tool 1A is a horizontal machining center.

[0074] The main body 10A has a setup station 700. The door section 20A includes a door 21A (hereinafter also referred to as the "left door 21A") located on the left side when viewed from the front of the machine tool 1A, and a door 22A (hereinafter also referred to as the "right door 22A") located on the right side. The left door 21A and the right door 22A are sliding doors. The left door 21A and the right door 22A are sliding doors that separate the setup station 700 from the external space of the machine tool 1A.

[0075] The left door 21A has a window 211A and a handle 212A. The right door 22A has a window 221A and a handle 222A. The handle 212A is provided on the right door 22A side in the Y-axis direction. The handle 222A is provided on the left door 21A side in the Y-axis direction. The handles 212A and 222A extend in the X-axis direction (vertical direction).

[0076] In the state shown in FIG. 8, the left door 21A and the right door 22A are closed. The ends of the left door 21A and the right door 22A are in contact with each other. When the left door 21A and the right door 22A are in an open state, they face each other in the Y-axis direction. When the left door 21A and the right door 22A are in an open state, they are housed inside the machine tool 1A. The left door 21A and the right door 22A are housed in a space in which the setup station 700 is installed.

[0077] Like the machine tool 1, the machine tool 1A having such a left door 21A and a right door 22A can also be configured to have the above-mentioned push-open function and intermediate position stop function.

[0078] (2) Second Modification Although the above description has been given taking as an example a machine tool having left and right doors, the machine tool may have only one door.

[0079] (3) Third Modification In the above, a default value for the threshold value Th is determined in advance, but the present invention is not limited to this. A predetermined number of trials (operations of applying an external force to the door) may be performed to estimate an average torque, and the estimated average torque may be used as the threshold value Th.

[0080] (4) Fourth Modification In the above description, the servo controller 81 performs control to open the door to which an external force is applied when the torque is equal to or greater than the threshold value Th. However, the present invention is not limited to this, and the servo controller 81 may be configured to perform control to open the door to which an external force is applied when the value of the armature current of the servo motor 60 is equal to or greater than the threshold value.

[0081] (5) Fifth Modification Although the above description has been given taking as an example a configuration in which the servo driver 70 detects torque, the present invention is not limited to this. The servo controller 81 may detect the torque instead of the servo driver 70.

[0082] The embodiments disclosed herein are merely examples and are not limited to the above. The scope of the present invention is defined by the claims, and it is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0083] 1,1A machine tool, 2 operation panel, 10,10A,61 main body, 20,20A door, 21,21A left door, 22,22A right door, 30,30A operation device, 31 upper housing, 32 lower housing, 33 hinge, 40 drive unit, 41,42 pulley, 43 belt, 51,52 gear, 60 servo motor, 62 rotary axis, 63 encoder, 70 servo driver, 80 motion controller, 81 servo controller, 100 machining area, 110 tool spindle, 211,211A,221,221A window, 212,212A,222,222A handle, 310 touch screen, 310G setting screen, 311 display, 312 touch panel, 320 input device, 321 Operation keys, 419,429 axes, 700 setup stations, 3110,3120 image objects, 3111,3121 toggle buttons, 3112 sliders, 3122 input fields, 3123,3124 buttons, SYS servo system.

Claims

1. Doors and a servo system for controlling the opening and closing of the door; The servo system includes: a servo motor having a rotary shaft and configured to open and close the door by rotation of the rotary shaft; a servo driver that operates the servo motor; a controller connected to the servo driver; When an external force is applied to the door in a direction to open the door while the door is maintained in a closed position by the servo system, the servo driver or the controller detects a torque acting on the rotation shaft due to the external force, The controller sends a command to the servo driver to rotate the servo motor in a direction to open the door, on condition that the torque is equal to or greater than a predetermined threshold.

2. further comprising an operation device communicably connected to the controller; The machine tool according to claim 1 , wherein the operation device accepts a first operation for changing the threshold value.

3. The operating device is a display that displays an image showing a plurality of levels of the threshold; The machine tool according to claim 2 , further comprising: an input device that accepts an operation of selecting one level from the plurality of levels as the first operation.

4. The machine tool according to claim 3 , wherein when the operation device receives a second operation, the controller stops the function of sending the command to the servo driver on condition that the torque is equal to or greater than the threshold value.

5. 2. The machine tool according to claim 1, wherein the command is a command to move the door to a pre-specified position.

6. 6. The machine tool according to claim 5, wherein the specified position is a position where the door is fully open.

7. It also has a processing area for processing the workpiece, The machine tool according to claim 1 , wherein the door is a sliding door that separates the machining area from an external space of the machine tool.

8. It also has a setup station, The machine tool according to claim 1 , wherein the door is a sliding door that separates the setup station from an external space of the machine tool.

9. 7. The machine tool according to claim 1, wherein, when an external force is applied to the door in a direction to close the door while the door is maintained in an open position by the servo system, the controller maintains the door in the open state even if a torque acting on the rotation shaft due to the external force in the direction to close the door becomes equal to or greater than the predetermined threshold.

10. a servo system having a servo motor, a servo driver, and a controller for controlling the opening and closing of a door of a machine tool, maintaining the door in a closed position; When an external force is applied to the door in a direction to open the door while the door is maintained in a closed position, the servo driver or the controller detects a torque acting on the servo motor due to the external force; and a step in which, on condition that the torque is equal to or greater than a predetermined threshold, the controller sends a command to the servo driver to rotate the servo motor in a direction to open the door.

Images