Door device for machine tool, and machine tool

Abstract

This door device for a machine tool comprises: a door that can slide in a first direction such that at least a portion of an opening of the machine tool is opened, and can slide in a second direction opposite from the first direction such that at least a portion of the opening is closed; a handle disposed on the door; a strain gauge that detects an operation of the handle; an air cylinder that applies assist force to the door; an air supply flow path via which the air cylinder and an air supply source are connected; a regulator that adjusts the pressure of air flowing through the air supply flow path; and a control device that controls the regulator on the basis of a signal from the strain gauge.

Description

Door device for a machine tool, and a machine tool

[0001] The present invention relates to a door device for a machine tool and a machine tool.

[0002] An auxiliary device for assisting the opening and closing of the door of a machine tool is known.

[0003] As a related art, Patent Document 1 discloses a door device for a machine tool. The door device for a machine tool described in Patent Document 1 includes a door slidable between a first position and a second position, a handle disposed on the door, at least one air cylinder that applies a first assist force to the door in a first direction from the first position to the second position, a first state that allows the door to move in the first direction or in a second direction from the second position to the first position without the first assist force, and an operation switch that switches the state of at least one switching valve between the first state and a second state in which the first assist force is applied to the door in the first direction.

[0004] Japanese Patent No. 6982713

[0005] An object of the present invention is to provide a door device for a machine tool and a machine tool capable of adjusting an assist force based on an operating force acting on a handle.

[0006] Embodiments of the present invention relate to the following door device for a machine tool and a machine tool.

[0007] (1) A door device for a machine tool comprising: a door that can slide in a first direction so as to open at least a portion of the opening of the machine tool, and a door that can slide in a second direction opposite to the first direction so as to close at least the portion of the opening; a handle disposed on the door; a strain gauge for detecting the operation of the handle; an air cylinder for providing an assisting force to the door; an air supply passage connecting the air cylinder and an air supply source; a regulator for adjusting the pressure of the air flowing through the air supply passage; and a control device for controlling the regulator based on a signal from the strain gauge. (2) A machine tool comprising: a work support device for supporting a workpiece; a machining head capable of holding a tool for machining the workpiece; a moving device for moving the machining head relative to the work support device; a numerical control device for controlling the moving device; a wall having an opening; and a door device, wherein the door device comprises: a door that can slide in a first direction so as to open at least a portion of the opening, and a door that can slide in a second direction opposite to the first direction so as to close at least the portion of the opening; a handle disposed on the door; a strain gauge for detecting the operation of the handle; an air cylinder for providing an assisting force to the door; an air supply passage connecting the air cylinder and an air supply source; a regulator for adjusting the pressure of the air flowing through the air supply passage; and a control device for controlling the regulator based on a signal from the strain gauge.

[0008] The present invention provides a door device for a machine tool and a machine tool that can adjust the assist force based on the operating force acting on the handle.

[0009] Figure 1 is a schematic diagram showing a door device for a machine tool in the first embodiment. Figure 2 is a schematic diagram showing a door device for a machine tool in the first embodiment. Figure 3 is a schematic diagram showing a door device for a machine tool in the first embodiment. Figure 4 is a schematic diagram showing a door device for a machine tool in the first embodiment. Figure 5 is a schematic diagram showing a door device for a machine tool in the first modified example of the first embodiment. Figure 6 is a schematic diagram showing a door device for a machine tool in the first embodiment. Figure 7 is a schematic diagram showing an example of the relationship between operating force and assist force. Figure 8 is a schematic diagram showing an example of the relationship between operating force and target pressure. Figure 9 is a schematic diagram showing how the control device can generate a first control signal corresponding to a first target pressure based on signals from strain gauges and parameters of the first group. Figure 10 is a schematic diagram showing how the control device can generate a second control signal corresponding to a second target pressure based on signals from strain gauges and parameters of the second group. Figure 11 is a schematic diagram illustrating another example of the relationship between operating force and assisting force. Figure 12 is a schematic cross-sectional view illustrating a part of the door device for a machine tool in the first embodiment. Figure 13 is a magnified view of the area enclosed by the dashed rectangle A1 in Figure 12. Figure 14 is a magnified view of the area enclosed by the dashed rectangle A2 in Figure 12. Figure 15 is a schematic perspective view illustrating a part of the door device for a machine tool in the first embodiment. Figure 16 is a schematic perspective view illustrating a part of the door device for a machine tool in the first embodiment. Figure 17 is a schematic perspective view illustrating an example of the arrangement of multiple strain gauges. Figure 18 is a schematic diagram illustrating the elongation of the first and second strain gauges due to torsional deformation. Figure 19 is a schematic diagram illustrating the contraction of the third and fourth strain gauges due to torsional deformation. Figure 20 is a schematic diagram illustrating how multiple strain gauges are arranged in a bridge circuit. Figure 21 schematically shows how one strain gauge is arranged in a bridge circuit. Figure 22 schematically shows how a dummy strain gauge is arranged in a bridge circuit. Figure 23 schematically shows a door device for a machine tool in a second embodiment.Figure 24 is a schematic diagram showing a door device for a machine tool in a second embodiment. Figure 25 is a schematic diagram showing an example of the arrangement of a movable pulley and / or air cylinder. Figure 26 is a schematic perspective view showing a machine tool in a third embodiment. Figure 27 is a schematic diagram showing how a numerical control device can control a controlled device. Figure 28 is a schematic diagram showing an example of a first image displayed on a display. Figure 29 is a schematic diagram showing another example of a first image displayed on a display.

[0010] The door device 1 for a machine tool and the machine tool 100 in the embodiment will be described below with reference to the drawings. In the following description of the embodiment, parts and components having the same function will be denoted by the same reference numerals, and repeated descriptions of parts and components denoted by the same reference numerals will be omitted.

[0011] (First Embodiment) The door device 1A for a machine tool in the first embodiment will be described with reference to Figures 1 to 22. Figures 1 to 4 are schematic diagrams showing the door device 1A for a machine tool in the first embodiment. Figure 5 is a schematic diagram showing the door device 1A for a machine tool in the first modified example of the first embodiment. Figure 6 is a schematic diagram showing the door device 1A for a machine tool in the first embodiment. Figure 7 is a schematic diagram showing an example of the relationship between operating force and assist force. Figure 8 is a schematic diagram showing an example of the relationship between operating force and target pressure. Figure 9 is a schematic diagram showing how the control device 66 can generate a first control signal C1 corresponding to a first target pressure based on the signal S from the strain gauge 40 and the first group of parameters PA. Figure 10 is a schematic diagram showing how the control device 66 can generate a second control signal C2 corresponding to a second target pressure based on the signal S from the strain gauge 40 and the second group of parameters PB. Figure 11 is a schematic diagram illustrating another example of the relationship between operating force and assisting force. Figure 12 is a schematic cross-sectional view illustrating a portion of the door device 1A for a machine tool in the first embodiment. Figure 13 is a magnified view of the area enclosed by the dashed rectangle A1 in Figure 12. Figure 14 is a magnified view of the area enclosed by the dashed rectangle A2 in Figure 12. Figures 15 and 16 are schematic perspective views illustrating a portion of the door device 1A for a machine tool in the first embodiment. Figure 17 is a schematic perspective view illustrating an example of the arrangement of a plurality of strain gauges 40. Figure 18 is a schematic diagram illustrating the elongation of the first strain gauge 40a and the second strain gauge 40b due to torsional deformation. Figure 19 is a schematic diagram illustrating the contraction of the third strain gauge 40c and the fourth strain gauge 40d due to torsional deformation. Figure 20 is a schematic diagram illustrating how a plurality of strain gauges 40 are arranged in a bridge circuit 4. Figure 21 schematically shows how one strain gauge 40 is arranged in the bridge circuit 4. Figure 22 schematically shows how a dummy strain gauge 41 is arranged in the bridge circuit 4.

[0012] As illustrated in Figure 1, the door device 1A for a machine tool in the first embodiment (hereinafter simply referred to as "door device 1A") comprises a door 2, a handle 3, a strain gauge 40, an air cylinder 5, an air supply passage FP, a regulator 61, and a control device 66.

[0013] Door 2 is slidable in a first direction DR1 and in a second direction DR2 opposite to the first direction DR1. More specifically, door 2 is slidable in the first direction DR1 so as to open at least a portion of the opening OP of the machine tool. Door 2 is also slidable in the second direction DR2 opposite to the first direction DR1 so as to close at least a portion of the opening OP of the machine tool.

[0014] In the examples shown in Figures 2 and 3, the door 2 is slidable between a first position Q1 (see Figure 2) that closes the opening OP in the wall 110 defining the internal area of ​​the machine tool and a second position Q2 (see Figure 3) that opens the opening OP. The direction from the first position Q1 to the second position Q2 corresponds to the first direction DR1, and the direction from the second position Q2 to the first position Q1 corresponds to the second direction DR2.

[0015] The handle 3 is located on the door 2. The handle 3 may be a handle attached to the door 2, or it may be a recess provided in a part of the door 2. In the example shown in Figure 2, when the handle 3 is operated in the first direction DR1, the door 2 moves from the first position Q1 to the second position Q2. In the example shown in Figure 3, when the handle 3 is operated in the second direction DR2 (in other words, the direction opposite to the first direction DR1), the door 2 moves from the second position Q2 to the first position Q1.

[0016] The strain gauge 40 detects the operation of the handle 3. More specifically, the strain gauge 40 detects the strain caused by the operation of the handle 3.

[0017] The air cylinder 5 provides assist force to the door 2. The air supply passage FP connects the air cylinder 5 to the air supply source 91.

[0018] The regulator 61 adjusts the pressure of the air flowing through the air supply channel FP. The regulator 61 is, for example, an electro-pneumatic regulator 61a. The electro-pneumatic regulator 61a adjusts the pressure of the air flowing through the air supply channel FP based on an electrical signal. More specifically, the electro-pneumatic regulator 61a adjusts the pressure of the air flowing through the air supply channel FP based on an electrical signal received from the control device 66, which will be described later. Alternatively, the regulator 61 may adjust the pressure of the air flowing through the air supply channel FP based on an optical signal received from the control device 66. In other words, the regulator 61 may be an optical / pneumatic converter.

[0019] In the example shown in Figure 2, the regulator 61 (for example, an electro-pneumatic regulator 61a, or an optical / pneumatic converter) is located in the air supply channel FP.

[0020] The control device 66 controls the regulator 61 (for example, an electro-pneumatic regulator 61a, or an optical / pneumatic converter) based on the signal S from the strain gauge 40.

[0021] The door device 1A in the first embodiment includes a strain gauge 40 for detecting the operation of the handle 3. The strain gauge 40 is capable of detecting the operating force acting on the handle 3. The door device 1A in the first embodiment includes an air cylinder 5 for applying an assist force to the door 2, an air supply passage FP connecting the air cylinder 5 and an air supply source 91, a regulator 61 for adjusting the pressure of the air flowing through the air supply passage FP, and a control device 66 for controlling the regulator 61 based on a signal S from the strain gauge 40. Therefore, the door device 1A in the first embodiment can adjust the assist force applied to the door 2 based on the operating force acting on the handle 3.

[0022] (Optional Additional Configurations) Next, with reference to Figures 1 to 22, optional additional configurations that can be adopted in the door device 1A for machine tools in the first embodiment, or in the door device 1B for machine tools in the second embodiment described later, will be explained.

[0023] (Air supply source 91) In the example shown in Figure 1, the door device 1A is equipped with an air supply source 91. The air supply source 91 is, for example, an air compressor.

[0024] (Air Cylinder 5) In the example shown in Figure 2, the air cylinder 5 has a first chamber 51. The air cylinder 5 provides a first assist force to the door 2 in the first direction DR1 by supplying air to the first chamber 51. In the example shown in Figure 2, air can be supplied to the first chamber 51 from the air supply source 91.

[0025] In the example shown in Figure 3, the air cylinder 5 has a second chamber 53. The air cylinder 5 applies a second assist force to the door 2 in the second direction DR2 by supplying air to the second chamber 53. In the example shown in Figure 3, air can be supplied to the second chamber 53 from the air supply source 91.

[0026] In the example shown in Figure 1, the air cylinder 5 has a first chamber 51, a second chamber 53, and a piston 54 positioned between the first chamber 51 and the second chamber 53. The air cylinder 5 may also have a rod 55 connected to the piston 54.

[0027] In the example shown in Figure 1, the air cylinder 5 has a first chamber 51 that is fluidly connected to an air supply source 91 via a first flow path FP1, and a second chamber 53 that is fluidly connected to the air supply source 91 via a second flow path FP2. The piston 54 is driven by the pressure difference between the first chamber 51 and the second chamber 53. The rod 55 moves together with the piston 54. The rod 55 is connected to the door 2. The rod 55 may be directly connected to the door 2, or it may be indirectly connected to the door 2 via a mechanical transmission element such as a belt, wire, cable, or gear.

[0028] The air cylinder 5 may include a first air cylinder and a second air cylinder. In other words, the door device 1A may use a plurality of air cylinders 5 to apply a first assist force and / or a second assist force to the door 2.

[0029] (Air supply channel FP) In the examples shown in Figures 2 and 3, the air supply channel FP includes a first channel FP1 that fluidly connects the first chamber 51 and the air supply source 91. In the examples shown in Figures 2 and 3, the air supply channel FP includes a second channel FP2 that fluidly connects the second chamber 53 and the air supply source 91. As illustrated in Figures 2 and 3, a portion of the first channel FP1 and a portion of the second channel FP2 may be shared (in the examples shown in Figures 2 and 3, the portion of the first channel FP1 between the air supply source 91 and the directional control valve 7 and the portion of the second channel FP2 between the air supply source 91 and the directional control valve 7 are shared). Alternatively, the first channel FP1 and the second channel FP2 may be completely independent of each other.

[0030] (Third flow path F3 and fourth flow path F4) In the example shown in Figure 1, the door device 1A includes a third flow path F3 that fluidly connects the first chamber 51 and the first atmospheric vent D1. In the example shown in Figure 1, a directional control valve 7 is located in the third flow path F3. A portion of the third flow path F3 may be shared with a portion of the first flow path FP1 (for example, the flow path between the first chamber 51 and the directional control valve 7 may be shared).

[0031] In the example shown in Figure 1, the door device 1A includes a fourth flow path F4 that fluidly connects the second chamber 53 and the second atmospheric vent D2. In the example shown in Figure 1, a directional control valve 7 is located in the fourth flow path F4. Part of the fourth flow path F4 may be shared with part of the second flow path FP2 (for example, the flow path between the second chamber 53 and the directional control valve 7 may be shared). In the example shown in Figure 1, the second atmospheric vent D2 is a different atmospheric vent from the first atmospheric vent D1. Alternatively, the second atmospheric vent D2 and the first atmospheric vent D1 may be shared.

[0032] (Directional control valve 7) As illustrated in Figures 1 to 3, the door device 1A may be equipped with a directional control valve 7. The directional control valve 7 switches the direction of the assist force between a first direction DR1 and a second direction DR2. In the example shown in Figure 1, the directional control valve 7 is located in the air supply passage FP.

[0033] In the examples shown in Figures 2 and 3, the control device 66 controls the directional control valve 7 based on the signal S from the strain gauge 40.

[0034] In the example shown in Figure 2, when the signal S from the strain gauge 40 indicates that the handle 3 is operated in the first direction DR1, the control device 66 controls the directional control valve 7 so that air is supplied to the first chamber 51. In this way, when the handle 3 is operated in the first direction DR1, a first assist force in the first direction DR1 is applied from the air cylinder 5 to the door 2.

[0035] More specifically, when the handle 3 is operated in the first direction DR1 (in other words, when the signal S from the strain gauge 40 indicates that the handle 3 is operated in the first direction DR1), the control device 66 transmits a first control command CM1 to the directional control valve 7. The directional control valve 7, upon receiving the first control command CM1, fluidly connects the first chamber 51 of the air cylinder 5 to the regulator 61. In this way, air is supplied from the air supply source 91 to the first chamber 51 of the air cylinder 5 via the regulator 61, and the air cylinder 5 provides the door 2 with a first assist force in the first direction DR1.

[0036] In the example shown in Figure 3, when the signal S from the strain gauge 40 indicates that the handle 3 is operated in the second direction DR2, the control device 66 controls the directional control valve 7 so that air is supplied to the second chamber 53. In this way, when the handle 3 is operated in the second direction DR2, a second assist force in the second direction DR2 is applied from the air cylinder 5 to the door 2.

[0037] More specifically, when the handle 3 is operated in the second direction DR2 (in other words, when the signal S from the strain gauge 40 indicates that the handle 3 is operated in the second direction DR2), the control device 66 transmits a second control command CM2 to the directional control valve 7. The directional control valve 7, upon receiving the second control command CM2, fluidly connects the second chamber 53 of the air cylinder 5 to the regulator 61. In this way, air is supplied from the air supply source 91 to the second chamber 53 of the air cylinder 5 via the regulator 61, and the air cylinder 5 provides the door 2 with a second assist force in the second direction DR2.

[0038] In the example shown in Figure 1, when the directional control valve 7 is in its default state J0, the first chamber 51 and the second chamber 53 are fluidly connected to the atmospheric vent D. Therefore, even in a power-off state where no power is supplied to the directional control valve 7, the door 2 can be freely moved in the first direction DR1 and the second direction DR2 without requiring significant operating force. In the example shown in Figure 1, manual movement of the door 2 in a power-off state is easier compared to the case where an assist force is provided by an electric motor.

[0039] In the example shown in Figure 1, when the power supply to the directional control valve 7 is cut off, the state of the directional control valve 7 is maintained in the default state J0. The directional control valve 7 is, for example, a solenoid valve. In this case, when the solenoid of the directional control valve 7 becomes energized, the state of the directional control valve 7 is switched from the default state J0 to a first state J1 (see Figure 2) in which a first assist force can be applied to the door 2 in the first direction DR1, or to a second state J2 (see Figure 3) in which a second assist force can be applied to the door 2 in the second direction DR2.

[0040] In the examples shown in Figures 1 to 3, the state of the directional control valve 7 can be switched between a default state J0 (see Figure 1) in which no assist force is applied to the door 2, a first state J1 (see Figure 2) in which a first assist force can be applied to the door 2 in the first direction DR1, and a second state J2 (see Figure 3) in which a second assist force can be applied to the door 2 in the second direction DR2.

[0041] In the first state J1 illustrated in Figure 2, a first assist force is applied to the door 2 in the first direction DR1. In the example shown in Figure 2, when the state of the directional control valve 7 is the first state J1, the first chamber 51 of the air cylinder 5 and the regulator 61 are fluidly connected. In the example shown in Figure 2, when the signal S from the strain gauge 40 indicates that the handle 3 is operated in the first direction DR1, the door 2 moves in the first direction DR1 due to the resultant force of the first assist force and the operator's operating force.

[0042] As illustrated in FIG. 2, when the state of the direction control valve 7 is in the first state J1, the atmosphere release port D (for example, the second atmosphere release port D2) and the second chamber 53 may be fluidly connected. In the examples described in FIGS. 2 and 4, the door 2 at the first position Q1 can be moved to an arbitrary position Q3 between the first position Q1 and the second position Q2 and stopped at the arbitrary position Q3.

[0043] In the second state J2 illustrated in FIG. 3, a second assist force is applied to the door 2 in the second direction DR2. In the example described in FIG. 3, when the state of the direction control valve 7 is in the second state J2, the second chamber 53 of the air cylinder 5 and the regulator 61 are fluidly connected. In the example described in FIG. 3, when the signal S from the strain gauge 40 indicates that the handle 3 is being operated in the second direction DR2, the door 2 moves in the second direction DR2 by the combined force of the second assist force and the operator's operating force.

[0044] As illustrated in FIG. 3, when the state of the direction control valve 7 is in the second state J2, the atmosphere release port D (for example, the first atmosphere release port D1) and the first chamber 51 may be fluidly connected. In the examples described in FIGS. 3 and 4, the door 2 at the second position Q2 can be moved to an arbitrary position Q3 between the first position Q1 and the second position Q2 and stopped at the arbitrary position Q3.

[0045] In the examples described in FIGS. 1 to 4, the direction control valve 7 is disposed between the regulator 61 and the air cylinder 5 in the direction along the air supply flow path FP connecting the air cylinder 5 and the air supply source 91.

[0046] In the examples described in FIGS. 1 to 4, since the direction control valve 7 is disposed between the regulator 61 and the air cylinder 5, the adjustment of the first assist force when the handle 3 is operated in the first direction DR1 and the adjustment of the second assist force when the handle 3 is operated in the second direction DR2 can be performed using one regulator 61.

[0047] In the examples described in FIGS. 1 to 4, the direction control valve 7 is constituted by one unit U capable of switching among three states. More specifically, the direction control valve 7 is a three-way valve. Alternatively, as illustrated in FIG. 5, the direction control valve 7 may be constituted by a first unit U1 capable of switching between two states and a second unit U2 capable of switching between two states.

[0048] (Regulator 61) In the example described in FIG. 6, the regulator 61 (more specifically, the electro-pneumatic regulator 61a) includes a pressure sensor 62, a valve 63 for adjusting the opening degree of the air supply passage FP, and a controller 64.

[0049] The pressure sensor 62 detects the pressure of the air supply passage FP (more specifically, the air pressure downstream of the valve 63). The detection signal SD corresponding to the pressure detected by the pressure sensor 62 is transmitted to the control device

[0050] 66 and / or the controller 64.

[0050] The valve 63 is controlled by the controller 64. In the example described in FIG. 6, the valve 63 is a solenoid valve. Alternatively, the valve 63 may be a piezo valve or other types of valves.

[0051] The controller 64 controls the valve 63 based on the control signal C (for example, the first control signal C1 described later or the second control signal C2 described later) received from the control device 66. More specifically, the controller 64 controls the valve 63 such that the pressure detected by the pressure sensor 62 becomes the target pressure indicated by the control signal C.

[0052] (Control device 66) The control device 66 controls the regulator 61 (for example, the electro-pneumatic regulator 61a) based on the signal S from the strain gauge 40. More specifically, the control device 66 controls the regulator 61 such that the pressure of the air supply passage FP (more specifically, the air pressure downstream of the valve 63 in the air supply passage FP) is changed according to the magnitude of the operating force acting on the handle 3 indicated by the signal S from the strain gauge 40.

[0053] In the example shown in Figure 6, the control device 66 comprises a memory 661 and a processor 662. The memory 661 stores the program PG and parameters. The control device 66 is, for example, a "Programmable Logic Controller" (hereinafter referred to as "PLC66a").

[0054] In the example shown in Figure 6, the control device 66 may derive a target pressure in the air supply channel FP based on the signal S from the strain gauge 40 and transmit a control signal C corresponding to the target pressure to the regulator 61 (more specifically, the controller 64).

[0055] The control device 66 may determine, based on the signal S from the strain gauge 40, whether the handle 3 is being operated in the first direction DR1 with a force exceeding the first lower threshold SL1 (see Figure 7). If the handle 3 is being operated in the first direction DR1 with a force exceeding the first lower threshold SL1 (see Figure 7), the control device 66 controls the regulator 61 and the directional control valve 7 so that a first assist force acts from the air cylinder 5 on the door 2 in the first direction DR1. More specifically, if the handle 3 is being operated in the first direction DR1 with a force exceeding the first lower threshold SL1 (see Figure 8), the control device 66 changes the target pressure of the air supply passage FP according to the magnitude of the operating force acting on the handle 3, as indicated by the signal S from the strain gauge 40. The control device 66 also transmits a control signal C corresponding to the changed target pressure to the regulator 61 and maintains the state of the directional control valve 7 in the first state J1 described above.

[0056] The control device 66 may determine, based on the signal S from the strain gauge 40, whether the handle 3 is being operated in the second direction DR2 with a force exceeding the second lower threshold SL2 (see Figure 7). If the handle 3 is being operated in the second direction DR2 with a force exceeding the second lower threshold SL2 (see Figure 7), the control device 66 controls the regulator 61 and the directional control valve 7 so that a second assist force acts from the air cylinder 5 on the door 2 in the second direction DR2. More specifically, if the handle 3 is being operated in the second direction DR2 with a force exceeding the second lower threshold SL2 (see Figure 8), the control device 66 changes the target pressure of the air supply passage FP according to the magnitude of the operating force acting on the handle 3, as indicated by the signal S from the strain gauge 40. The control device 66 also transmits a control signal C corresponding to the changed target pressure to the regulator 61 and maintains the state of the directional control valve 7 in the second state J2 described above.

[0057] If the control device 66 determines, based on the signal S from the strain gauge 40, that the operating force acting on the handle 3 is less than or equal to a predetermined value, the control device 66 may shut off the fluid connection between the air supply source 91 and the air cylinder 5. If the control device 66 determines, based on the signal S from the strain gauge 40, that the operating force acting on the handle 3 is less than or equal to a predetermined value, the control device 66 may maintain the valve 63 of the regulator 61 in a closed state, or maintain the state of the directional control valve 7 in the default state J0.

[0058] In the example shown in Figure 7, based on the signal S from the strain gauge 40, if the control device 66 determines that the operating force acting on the handle 3 in the first direction DR1 (hereinafter referred to as the "first operating force") is less than or equal to the first lower limit threshold SL1, and the operating force acting on the handle 3 in the second direction DR2 (hereinafter referred to as the "second operating force") is less than or equal to the second lower limit threshold SL2, the control device 66 shuts off the air supply passage FP connecting the air supply source 91 and the air cylinder 5. In this case, it is prevented that an assist force will be unintentionally generated due to the operator touching the door 2. The first lower limit threshold SL1 is, for example, any value between 0.1 kgf and 4 kgf (or any value between 1 kgf and 4 kgf). The second lower limit threshold SL2 is, for example, any value between 0.1 kgf and 4 kgf (or any value between 1 kgf and 4 kgf). As illustrated in Figure 7, the value of the second lower threshold SL2 may be the same as the value of the first lower threshold SL1. The air supply channel FP may be shut off by the control device 66 controlling the regulator 61, or by the control device 66 maintaining the state of the directional control valve 7 in the default state J0.

[0059] (Magnitude of assist force) In the example shown in Figure 7, the control device 66 controls the regulator 61 (more specifically, the electro-pneumatic regulator 61a) so that the magnitude of the assist force applied to the door 2 changes according to the magnitude of the operating force acting on the handle 3. In this case, compared to the case where the assist force is always constant, the operator is less likely to experience discomfort caused by the assist force. As illustrated in Figure 7, the control device 66 may also control the regulator (more specifically, the electro-pneumatic regulator 61a) so that the magnitude of the assist force increases nonlinearly in response to an increase in the magnitude of the operating force acting on the handle 3.

[0060] In this specification, the first assist ratio is defined as the magnitude of the first assist force applied to the first direction DR1 with respect to the magnitude of the first operating force applied to the handle 3 in the first direction DR1. In this specification, the second assist ratio is defined as the magnitude of the second assist force applied to the second direction DR2 with respect to the magnitude of the second operating force applied to the handle 3 in the second direction DR2.

[0061] As illustrated in Figure 7, in the first range RA1 where the first operating force acting on the handle 3 in the first direction DR1 is greater than the first lower limit threshold SL1 and less than or equal to the first value V1, the control device 66 may nonlinearly increase the first assist ratio in response to the increase in the first operating force. In the example shown in Figure 7, the first assist ratio is "1.44" when the first operating force is "3", the first assist ratio is "2.17" when the first operating force is "4", and the first assist ratio is "2.6" when the first operating force is "5".

[0062] As illustrated in Figure 7, in the second range RA2 where the first operating force acting on the handle 3 in the first direction DR1 is greater than the first value V1 and less than or equal to the first upper limit threshold SH1, the control device 66 may nonlinearly decrease the first assist ratio in response to the increase in the first operating force. In the example shown in Figure 7, the first assist ratio is "2.17" when the first operating force is "6", the first assist ratio is "1.63" when the first operating force is "8", and the first assist ratio is "1.3" when the first operating force is "10".

[0063] As illustrated in Figure 7, in the third range RA3 where the second operating force acting on the handle 3 in the second direction DR2 is greater than the second lower threshold SL2 and less than or equal to the second value V2, the control device 66 may nonlinearly increase the second assist ratio in response to the increase in the second operating force. As illustrated in Figure 7, in the fourth range RA4 where the second operating force acting on the handle 3 in the second direction DR2 is greater than the second value V2 and less than or equal to the second upper threshold SH2, the control device 66 may nonlinearly decrease the second assist ratio in response to the increase in the second operating force.

[0064] In the example shown in Figure 8, the control device 66 changes the target pressure in the air supply passage FP (hereinafter referred to as "first target pressure T1") in accordance with the change in the first operating force acting on the handle 3 in the first direction DR1. More specifically, the first target pressure T1 is the target pressure downstream of the valve 63 of the regulator 61 (see Figure 6) in the air supply passage FP when the first operating force acts on the handle 3 in the first direction DR1.

[0065] In the example shown in Figure 8, the control device 66, based on the signal S from the strain gauge 40, determines that the first operating force acting on the handle 3 in the first direction DR1 is greater than the first lower threshold SL1 and less than or equal to the first value V1, and increases the first target pressure T1 in accordance with the increase in the first operating force. In other words, in the first range RA1 where the first operating force acting on the handle 3 in the first direction DR1 is greater than the first lower threshold SL1 and less than or equal to the first value V1, the control device 66 controls the regulator 61 so that the pressure in the air supply passage FP (more specifically, the air pressure downstream of the valve 63 in the air supply passage FP) increases in accordance with the increase in the first operating force. In this way, the first assist force in the first direction DR1 can be gradually increased in the initial stage of operating the handle 3 in the first direction DR1.

[0066] In the example shown in Figure 8, the control device 66, based on the signal S from the strain gauge 40, determines that the first operating force acting on the handle 3 in the first direction DR1 is greater than the first value V1 and less than or equal to the first upper limit threshold SH1, and maintains the value of the first target pressure T1. In other words, in the second range RA2 where the first operating force acting on the handle 3 in the first direction DR1 is greater than the first value V1 and less than or equal to the first upper limit threshold SH1, the control device 66 controls the regulator 61 so that the pressure in the air supply passage FP (more specifically, the air pressure downstream of the valve 63 in the air supply passage FP) is substantially maintained. In this way, the first assist force in the first direction DR1 is substantially maintained during the intermediate stage of operating the handle 3 in the first direction DR1, and the acceleration of the door 2 in the first direction DR1 is suppressed. That is, in the second range RA2 described above, the control device 66 decreases the first assist ratio described above in accordance with the increase in the first operating force acting on the handle 3 in the first direction DR1.

[0067] When the operating force acting on the handle 3 in the first direction DR1 is defined as the first operating force, the range in which the first operating force is greater than the first lower limit threshold SL1 and less than or equal to the first value V1 is defined as the first range RA1, the range in which the first operating force is greater than the first value V1 and less than or equal to the first upper limit threshold SH1 is defined as the second range RA2, the rate of increase of the pressure in the air supply passage FP (more specifically, the air pressure downstream of the valve 63 in the air supply passage FP) in response to the increase in the first operating force in the first range RA1 is defined as the first increase rate IN1, and the rate of increase of the pressure in the air supply passage FP (more specifically, the air pressure downstream of the valve 63 in the air supply passage FP) in response to the increase in the first operating force in the second range RA2 is defined as the second increase rate IN2, the control device 66 may control the regulator 61 such that the second increase rate IN2 is less than the first increase rate IN1. In the example shown in Figure 8, the second increase rate IN2 is zero.

[0068] In the example shown in Figure 8, if the control device 66 determines, based on the signal S from the strain gauge 40, that the first operating force acting on the handle 3 in the first direction DR1 is greater than the first upper limit threshold SH1, the control device 66 shuts off the air supply passage FP connecting the air supply source 91 and the air cylinder 5. In this case, even if excessive operating force is applied to the handle 3, excessive acceleration of the door 2 in the first direction DR1 is suppressed by eliminating the assist force. In this way, damage to the handle 3 or the support body 45 described later is suppressed. The shutting off of the air supply passage FP may be performed by the control device 66 controlling the regulator 61, or by the control device 66 changing the state of the directional control valve 7 from the first state J1 to the default state J0. In addition, the operator may be warned that excessive operating force has been applied to the handle 3 by displaying an alarm at the same time as the shutting off of the air supply passage FP (for example, by displaying an alarm on a display of the door device 1 or machine tool 100).

[0069] In the example shown in Figure 8, the control device 66 changes the target pressure in the air supply passage FP (hereinafter referred to as "second target pressure T2") in accordance with the change in the second operating force applied to the handle 3 in the second direction DR2. More specifically, the second target pressure T2 is the target pressure downstream of the valve 63 of the regulator 61 (see Figure 6) in the air supply passage FP when the second operating force is applied to the handle 3 in the second direction DR2.

[0070] In the example shown in Figure 8, the control device 66, based on the signal S from the strain gauge 40, determines that the second operating force acting on the handle 3 in the second direction DR2 is greater than the second lower threshold SL2 and less than or equal to the second value V2, and increases the second target pressure T2 in accordance with the increase in the second operating force. In other words, in the third range RA3 where the second operating force acting on the handle 3 in the second direction DR2 is greater than the second lower threshold SL2 and less than or equal to the second value V2, the control device 66 controls the regulator 61 so that the pressure in the air supply passage FP (more specifically, the air pressure downstream of the valve 63 in the air supply passage FP) increases in accordance with the increase in the second operating force. In this way, the second assist force in the second direction DR2 can be gradually increased in the initial stage of operating the handle 3 in the second direction DR2.

[0071] In the example shown in Figure 8, the control device 66, based on the signal S from the strain gauge 40, determines that the second operating force acting on the handle 3 in the second direction DR2 is greater than the second value V2 and less than or equal to the second upper limit threshold SH2, and maintains the value of the second target pressure T2. In other words, in the fourth range RA4 where the second operating force acting on the handle 3 in the second direction DR2 is greater than the second value V2 and less than or equal to the second upper limit threshold SH2, the control device 66 controls the regulator 61 so that the pressure in the air supply passage FP (more specifically, the air pressure downstream of the valve 63 in the air supply passage FP) is substantially maintained. In this way, the second assist force in the second direction DR2 is substantially maintained during the intermediate stage of operating the handle 3 in the second direction DR2, and the acceleration of the door 2 in the second direction DR2 is suppressed. That is, in the fourth range RA4 described above, the control device 66 decreases the second assist ratio described above in accordance with the increase in the second operating force acting on the handle 3 in the second direction DR2.

[0072] When the operating force acting on the handle 3 in the second direction DR2 is defined as the second operating force, the range in which the second operating force is greater than the second lower threshold SL2 and less than or equal to the second value V2 is defined as the third range RA3, the range in which the second operating force is greater than the second value V2 and less than or equal to the second upper threshold SH2 is defined as the fourth range RA4, the rate of increase of the pressure in the air supply passage FP (more specifically, the air pressure downstream of the valve 63 in the air supply passage FP) in response to the increase in the second operating force in the third range RA3 is defined as the third increase rate IN3, and the rate of increase of the pressure in the air supply passage FP (more specifically, the air pressure downstream of the valve 63 in the air supply passage FP) in response to the increase in the second operating force in the fourth range RA4 is defined as the fourth increase rate IN4, the control device 66 may control the regulator 61 such that the fourth increase rate IN4 is smaller than the third increase rate IN3. In the example shown in Figure 8, the fourth increase rate IN4 is zero. In the example shown in Figure 8, the third growth rate IN3 is different from the first growth rate IN1.

[0073] In the example shown in Figure 8, if the control device 66 determines, based on the signal S from the strain gauge 40, that the second operating force acting on the handle 3 in the second direction DR2 is greater than the second upper limit threshold SH2, the control device 66 shuts off the air supply passage FP connecting the air supply source 91 and the air cylinder 5. In this case, even if excessive operating force is applied to the handle 3, excessive acceleration of the door 2 in the second direction DR2 is suppressed by eliminating the assist force. In this way, damage to the handle 3 or the support body 45 described later is suppressed. The shutting off of the air supply passage FP may be performed by the control device 66 controlling the regulator 61, or by the control device 66 changing the state of the directional control valve 7 from the second state J2 to the default state J0. In addition, the operator may be warned that excessive operating force has been applied to the handle 3 by displaying an alarm at the same time as the shutting off of the air supply passage FP (for example, by displaying an alarm on a display of the door device 1 or machine tool 100).

[0074] In the example shown in Figure 9, the memory 661 stores a first group of parameters PA that define the change in the first target pressure T1 of the air supply passage FP (more specifically, the first target pressure T1 downstream of the valve 63 in the air supply passage FP) in response to a change in the first operating force acting on the handle 3 in a first direction DR1.

[0075] When the signal S from the strain gauge 40 indicates that the handle 3 is being operated in the first direction DR1, the control device 66 (more specifically, the processor 662 executing the program PG) generates a first control signal C1 corresponding to the first target pressure T1 based on the signal S from the strain gauge 40 and the first group of parameters PA. More specifically, the control device 66 (more specifically, the processor 662 executing the program PG) derives a first target pressure T1 corresponding to the magnitude of the first operating force acting on the handle 3 in the first direction DR1 based on the signal S from the strain gauge 40 and the first group of parameters PA, and generates a first control signal C1 corresponding to the first target pressure T1. The control device 66 also transmits the first control signal C1 to the regulator 61 (more specifically, the electro-pneumatic regulator 61a). The regulator 61 (more specifically, the controller 64) that receives the first control signal C1 controls the valve 63 so that the pressure in the air supply path FP (more specifically, the air pressure downstream of the valve 63 in the air supply path FP) becomes the first target pressure T1.

[0076] In the example shown in Figure 9, the first group of parameters PA includes a first parameter PA1 that defines the first lower threshold SL1 (see Figure 8) described above. In the example shown in Figure 9, the first group of parameters PA includes a second parameter PA2 that defines the first increase rate IN1 (see Figure 8) described above. In the example shown in Figure 9, the first group of parameters PA includes a third parameter PA3 that defines the maximum value of the pressure in the air supply passage FP (more specifically, the air pressure downstream of the valve 63 in the air supply passage FP) when a first operating force is applied to the handle 3 in a first direction DR1 (hereinafter referred to as "first maximum value MA1"; see Figure 8). In the example shown in Figure 9, the first group of parameters PA includes a fourth parameter PA4 that defines the first upper threshold SH1 (see Figure 8) described above.

[0077] In the example shown in Figure 10, the memory 661 stores a second group of parameters PB that define the change in the second target pressure T2 of the air supply passage FP (more specifically, the second target pressure T2 downstream of the valve 63 in the air supply passage FP) in response to a change in the second operating force acting on the handle 3 in the second direction DR2.

[0078] When the signal S from the strain gauge 40 indicates that the handle 3 is being operated in the second direction DR2, the control device 66 (more specifically, the processor 662 executing the program PG) generates a second control signal C2 corresponding to the second target pressure T2 based on the signal S from the strain gauge 40 and the second group of parameters PB. More specifically, the control device 66 (more specifically, the processor 662 executing the program PG) derives a second target pressure T2 corresponding to the magnitude of the second operating force acting on the handle 3 in the second direction DR2 based on the signal S from the strain gauge 40 and the second group of parameters PB, and generates a second control signal C2 corresponding to the second target pressure T2. The control device 66 also transmits the second control signal C2 to the regulator 61 (more specifically, the electro-pneumatic regulator 61a). The regulator 61 (more specifically, the controller 64) that receives the second control signal C2 controls the valve 63 so that the pressure in the air supply path FP (more specifically, the air pressure downstream of the valve 63 in the air supply path FP) becomes the second target pressure T2.

[0079] In the example shown in Figure 10, the second group of parameters PB includes a fifth parameter PB1 that defines the second lower threshold SL2 (see Figure 8) described above. In the example shown in Figure 10, the second group of parameters PB includes a sixth parameter PB2 that defines the third increase rate IN3 (see Figure 8) described above. In the example shown in Figure 10, the second group of parameters PB includes a seventh parameter PB3 that defines the maximum value of the pressure in the air supply passage FP (more specifically, the air pressure downstream of the valve 63 in the air supply passage FP) when a second operating force is applied to the handle 3 in the second direction DR2 (hereinafter referred to as the "second maximum value MA2"; see Figure 8). In the example shown in Figure 10, the second group of parameters PB includes an eighth parameter PB4 that defines the second upper threshold SH2 (see Figure 8) described above.

[0080] In the examples shown in Figures 9 and 10, the first group of parameters PA stored in memory 661 can be changed. The second group of parameters PB also stored in memory 661 can be changed. By changing the first group of parameters PA and / or the second group of parameters PB, the shape of the graph shown in Figure 7 or Figure 8 is changed.

[0081] In the examples shown in Figures 7 and 11, the parameter that defines the change in the magnitude of the first assist force in the first direction DR1 in response to a change in the magnitude of the first operating force acting on the handle 3 in the first direction DR1 (more specifically, the first group of parameters PA described above) can be changed. Also, in the examples shown in Figures 7 and 11, the parameter that defines the change in the magnitude of the second assist force in the second direction DR2 in response to a change in the magnitude of the second operating force acting on the handle 3 in the second direction DR2 (more specifically, the second group of parameters PB described above) can be changed.

[0082] In this case, the parameters that define the change in assist force in response to changes in the magnitude of the operating force acting on the handle 3 can be adjusted to suit the operator's physique or preference.

[0083] In the example shown in Figure 2, the first surface of the piston 54 (hereinafter referred to as the "first pressure-receiving surface 54a") is pressed by air supplied from the air supply channel FP, and in the example shown in Figure 3, the second surface of the piston 54 (hereinafter referred to as the "second pressure-receiving surface 54b") is pressed by air supplied from the air supply channel FP. Under the condition that the pressure in the air supply channel FP is constant, the first assist force in the first direction DR1 (see Figure 2) does not match the second assist force in the second direction DR2 (see Figure 3) due to the difference in the area of ​​the first pressure-receiving surface 54a and the second pressure-receiving surface 54b. In contrast, in the examples shown in Figures 8 to 10, the imbalance in assist force caused by the area difference between the two pressure-receiving surfaces can be corrected by adjusting the first group of parameters PA and / or the second group of parameters PB described above.

[0084] For example, in the example shown in Figure 8, the first growth rate IN1 is different from the third growth rate IN3. More specifically, the first growth rate IN1 is greater than the third growth rate IN3 so that the imbalance in assist force caused by the difference in area between the two pressure-receiving surfaces is corrected. In the example shown in Figure 8, the first maximum value MA1 is different from the second maximum value MA2. More specifically, the first maximum value MA1 is greater than the second maximum value MA2 so that the imbalance in assist force caused by the difference in area between the two pressure-receiving surfaces is corrected.

[0085] In the example shown in Figure 6, the control device 66 is located in a location other than the door 2. Alternatively, the control device 66 may be located in the door 2.

[0086] (Door 2) In the examples shown in Figures 2 and 3, door 2 is a door that can slide in a direction substantially parallel to the horizontal plane.

[0087] In the examples shown in Figures 2 and 3, there is one door 2. Alternatively, there may be two or more doors 2. In this case, each of the multiple doors opens and closes a portion of the opening OP. If the door device 1A has multiple doors, each of the multiple doors may be provided with a mechanism for providing assist force. Alternatively, the door 2 may be a sliding door having a first panel and a second panel that is slidably connected to the first panel. In this case, when the opening OP is opened, the first panel and the second panel are overlapped, and when the opening OP is closed, the second panel may be unfolded relative to the first panel so that the overlapping area between the first panel and the second panel is reduced. Furthermore, the second panel may be provided with a handle 3, and the second panel may be provided with a mechanism for providing assist force. Note that the number of doors 2, or the type of doors 2, is not limited to the examples described above.

[0088] (Handle 3) In this specification, the direction from the bottom 2w of the door 2 toward the top 2u of the door is defined as the third direction DR3.

[0089] In the example shown in Figure 1, the handle 3 extends along the third direction DR3. The handle 3 may have an upper portion 31 connected to the door 2, a lower portion 33 connected to the door 2, and an intermediate portion 35 that is grasped by the operator. The intermediate portion 35 connects the upper portion 31 and the lower portion 33. A space SP (see Figure 12) may be formed between the intermediate portion 35 and the door 2, into which four fingers of the hand can be inserted simultaneously. Note that the shape or type of the handle 3 is not limited to the example described above.

[0090] (Support 45) In the example shown in Figure 12, the door device 1A includes a support 45 (more specifically, a bracket 450) that supports the strain gauge 40.

[0091] In the example shown in Figure 13, the support 45 (more specifically, the bracket 450) has a first portion 45a fixed to the door 2, a second portion 45b to which the handle 3 is fixed, and a third portion 45c on which the strain gauge 40 is positioned. The third portion 45c is positioned between the first portion 45a and the second portion 45b.

[0092] When the handle 3 is operated, strain is likely to occur in the region between the first portion 45a, which is fixed to the door 2, and the second portion 45b, to which the handle 3 is fixed. In the example shown in Figure 13, a strain gauge 40 is positioned in the third portion 45c between the first portion 45a and the second portion 45b. Therefore, the strain gauge 40 can suitably detect the strain caused by the operation of the handle 3.

[0093] In the example shown in Figure 12, the strain gauge 40 includes a first strain gauge 40a and a second strain gauge 40b.

[0094] In the example shown in Figure 12, the support 45 (more specifically, the bracket 450) has a first portion 45a fixed to the door 2, a second portion 45b to which the handle 3 is fixed, a third portion 45c on which the first strain gauge 40a is positioned, a fourth portion 45d fixed to the door 2, a fifth portion 45e to which the handle 3 is fixed, and a sixth portion 45f on which the second strain gauge 40b is positioned. The third portion 45c is positioned between the first portion 45a and the second portion 45b, and the sixth portion 45f is positioned between the fourth portion 45d and the fifth portion 45e.

[0095] When the handle 3 is operated, strain is likely to occur in the region between the first portion 45a fixed to the door 2 and the second portion 45b to which the handle 3 is fixed, and in the region between the fourth portion 45d fixed to the door 2 and the fifth portion 45e to which the handle 3 is fixed. In the example shown in Figure 12, the first strain gauge 40a is positioned in the third portion 45c between the first portion 45a and the second portion 45b, and the second strain gauge 40b is positioned in the sixth portion 45f between the fourth portion 45d and the fifth portion 45e. Therefore, the first strain gauge 40a and the second strain gauge 40b can suitably detect the strain caused by the operation of the handle 3.

[0096] In the example shown in Figure 12, the first portion 45a is positioned higher than the fourth portion 45d.

[0097] In the example shown in Figure 12, the second portion 45b is positioned higher than the fifth portion 45e. More specifically, the upper portion 31 of the handle 3 is fixed to the second portion 45b of the support 45, and the lower portion 33 of the handle 3 is fixed to the fifth portion 45e of the support 45.

[0098] As illustrated in Figure 15, the first strain gauge 40a may be positioned on the first side portion 45c-1 of the third portion 45c described above. In the example shown in Figure 15, the first side portion 45c-1 of the third portion 45c is the side portion of the third portion 45c on the first direction DR1 side.

[0099] As illustrated in Figure 15, the second strain gauge 40b may be positioned on the first side portion 45f-1 of the sixth portion 45f described above. In the example shown in Figure 15, the first side portion 45f-1 of the sixth portion 45f is the side portion of the sixth portion 45f on the first direction DR1 side.

[0100] As illustrated in Figure 16, the strain gauge 40 may include a third strain gauge 40c positioned on the second side portion 45c-2 of the third portion 45c described above. In the example shown in Figure 16, the second side portion 45c-2 of the third portion 45c is the side portion of the third portion 45c on the second direction DR2 side.

[0101] As illustrated in Figure 16, the strain gauge 40 may include a fourth strain gauge 40d positioned on the second side portion 45f-2 of the sixth portion 45f described above. In the example shown in Figure 16, the second side portion 45f-2 of the sixth portion 45f is the side portion of the sixth portion 45f on the second direction DR2 side.

[0102] In the example shown in Figures 15 and 16, the strain gauge 40 includes a first strain gauge 40a positioned on the first side portion 45c-1 of the third portion 45c, a second strain gauge 40b positioned on the first side portion 45f-1 of the sixth portion 45f, a third strain gauge 40c positioned on the second side portion 45c-2 of the third portion 45c, and a fourth strain gauge 40d positioned on the second side portion 45f-2 of the sixth portion 45f. In this case, strain in the support 45 can be suitably detected using at least four strain gauges (40a, 40b, 40c, 40d). In other words, strain in the support 45 fixed to the handle 3 can be suitably detected regardless of which position of the handle 3 is gripped and operated.

[0103] In the examples shown in Figures 12 to 16, the support 45 (more specifically, the bracket 450) is fixed to the door 2 in such a way that it can undergo torsional deformation.

[0104] More specifically, in the example shown in Figure 13, the first portion 45a is fixed to the door 2 and the second portion 45b is fixed to the handle 3. Therefore, when the handle 3 is operated in the first direction DR1, torsional deformation occurs in the third portion 45c between the first portion 45a and the second portion 45b. In the examples shown in Figures 12, 13, 15, and 16, strain gauges 40 (e.g., a first strain gauge 40a and / or a third strain gauge 40c) are placed in the third portion 45c where torsional deformation occurs when the handle 3 is operated in the first direction DR1. Thus, the strain gauges 40 (e.g., a first strain gauge 40a and / or a third strain gauge 40c) placed in the third portion 45c can suitably detect the strain caused by torsional deformation.

[0105] In the example shown in Figure 14, the fourth portion 45d is fixed to the door 2 and the fifth portion 45e is fixed to the handle 3. Therefore, when the handle 3 is operated in the first direction DR1, torsional deformation occurs in the sixth portion 45f between the fourth portion 45d and the fifth portion 45e. In the examples shown in Figures 12, 14, 15, and 16, strain gauges 40 (e.g., a second strain gauge 40b and / or a fourth strain gauge 40d) are placed in the sixth portion 45f where torsional deformation occurs when the handle 3 is operated in the first direction DR1. Thus, the strain gauges 40 (e.g., a second strain gauge 40b and / or a fourth strain gauge 40d) placed in the sixth portion 45f can suitably detect the strain caused by torsional deformation.

[0106] From the viewpoint of suitably detecting strain caused by torsional deformation, it is preferable that the strain gauge 40 (for example, the first strain gauge 40a) is placed on the support 45 in a state inclined with respect to the longitudinal direction of the support 45. In this specification, the state in which the strain gauge 40 is inclined with respect to the longitudinal direction of the support 45 means a state in which the extending direction of the electrical resistor 401 of the strain gauge 40 is inclined with respect to the longitudinal direction of the support 45.

[0107] In the examples shown in Figures 12, 13, and 15, the first strain gauge 40a is positioned on one side of the third portion 45c where torsional deformation occurs when the handle 3 is operated in the first direction DR1. Furthermore, as illustrated in Figure 15, the first strain gauge 40a is positioned on the support 45 at an angle to the longitudinal direction of the support 45. The angle of inclination of the first strain gauge 40a with respect to the longitudinal direction of the support 45 is, for example, about 45 degrees. However, this angle of inclination is not limited to about 45 degrees.

[0108] In the example shown in Figure 16, the third strain gauge 40c is positioned on the other side of the third portion 45c where torsional deformation occurs when the handle 3 is operated in the first direction DR1. The third strain gauge 40c is also positioned on the support 45 at an angle to the longitudinal direction of the support 45. If the third strain gauge 40c were positioned parallel or perpendicular to the longitudinal direction of the support 45, the third strain gauge 40c would not expand or contract, and therefore would not be able to suitably detect strain. By positioning the third strain gauge 40c at an angle to the longitudinal direction of the support 45, the third strain gauge 40c expands and contracts suitably, and therefore can suitably detect strain. The angle of inclination of the third strain gauge 40c with respect to the longitudinal direction of the support 45 is, for example, about 45 degrees. However, this angle of inclination is not limited to about 45 degrees.

[0109] In the examples shown in Figures 15 and 16, the third portion 45c includes a thinned region 451c and a non-thinned region 453c that is thicker than the thinned region 451c. In this case, when the handle 3 is operated in the first direction DR1, distortion is likely to occur in the thinned region 451c. In the examples shown in Figures 15 and 16, a first gap G1 exists between the thinned region 451c and the door 2. In this case, when the handle 3 is operated in the first direction DR1, distortion is likely to occur in the thinned region 451c.

[0110] In the example shown in Figure 15, a strain gauge 40 (for example, a first strain gauge 40a) is placed in the thinned-wall region 451c. In this case, the strain gauge 40 can suitably detect the strain occurring in the thinned-wall region 451c. In the example shown in Figure 16, a third strain gauge 40c is placed in the thinned-wall region 451c. In this case, the third strain gauge 40c can suitably detect the strain occurring in the thinned-wall region 451c.

[0111] In the examples shown in Figures 15 and 16, a first hole 452c is formed in the third portion 45c. In the example shown in Figure 15, a strain gauge 40 (for example, a first strain gauge 40a) is placed in the thinned region of the third portion 45c (in other words, the thinned region 451c) formed by the first hole 452c. In the example shown in Figure 16, a third strain gauge 40c is placed in the thinned region of the third portion 45c (in other words, the thinned region 451c) formed by the first hole 452c.

[0112] In the examples shown in Figures 12, 14, and 15, the second strain gauge 40b is positioned on one side of the sixth portion 45f where torsional deformation occurs when the handle 3 is operated in the first direction DR1. Furthermore, as illustrated in Figure 15, the second strain gauge 40b is positioned on the support 45 at an angle to the longitudinal direction of the support 45. The angle of inclination of the second strain gauge 40b with respect to the longitudinal direction of the support 45 is, for example, about 45 degrees. However, this angle of inclination is not limited to about 45 degrees.

[0113] In the example shown in Figure 16, the fourth strain gauge 40d is positioned on the other side of the sixth portion 45f where torsional deformation occurs when the handle 3 is operated in the first direction DR1. The fourth strain gauge 40d is also positioned on the support 45 at an angle with respect to the longitudinal direction of the support 45. The angle of inclination of the fourth strain gauge 40d with respect to the longitudinal direction of the support 45 is, for example, about 45 degrees. However, this angle of inclination is not limited to about 45 degrees.

[0114] In the examples shown in Figures 15 and 16, the sixth portion 45f includes a thinned region 451f and a non-thinned region 453f that is thicker than the thinned region 451f. In this case, when the handle 3 is operated in the first direction DR1, distortion is likely to occur in the thinned region 451f. In the examples shown in Figures 15 and 16, a second gap G2 exists between the thinned region 451f and the door 2. In this case, when the handle 3 is operated in the first direction DR1, distortion is likely to occur in the thinned region 451f.

[0115] In the example shown in Figure 15, a second strain gauge 40b is placed in the thinned region 451f. In this case, the second strain gauge 40b can suitably detect the strain occurring in the thinned region 451f. In the example shown in Figure 16, a fourth strain gauge 40d is placed in the thinned region 451f. In this case, the fourth strain gauge 40d can suitably detect the strain occurring in the thinned region 451f.

[0116] In the examples shown in Figures 15 and 16, a second hole 452f is formed in the sixth portion 45f. In the example shown in Figure 15, a second strain gauge 40b is placed in the thinned region (in other words, the thinned region 451f) of the sixth portion 45f due to the second hole 452f. In the example shown in Figure 16, a fourth strain gauge 40d is placed in the thinned region (in other words, the thinned region 451f) of the sixth portion 45f due to the second hole 452f.

[0117] In the examples shown in Figures 12 to 16, the door 2 comprises a first frame 21. In the examples shown in Figures 12 to 14, the handle 3 is positioned on the surface 211 of the first frame 21, and the support 45 (more specifically, the bracket 450) is positioned on the back surface 213 of the first frame 21. In the examples shown in Figures 12 to 14, the first frame 21 of the door 2 is sandwiched between the handle 3 and the support 45 (more specifically, the bracket 450).

[0118] As illustrated in Figure 13, the first frame 21 may have a substantially L-shape in a cross-section perpendicular to the third direction DR3. Alternatively, the first frame 21 may have a substantially rectangular shape or a substantially C-shape in a cross-section perpendicular to the third direction DR3.

[0119] In the examples shown in Figures 12 to 16, the support 45 extends along the third direction DR3. As illustrated in Figure 12, the longitudinal direction of the support 45 may coincide with the third direction DR3. In the examples shown in Figures 12 to 16, the support 45 is a rod-shaped body (more specifically, a flat bar). The support 45 may have a substantially rectangular shape in a cross section perpendicular to the third direction DR3. In this case, it is easier to place strain gauges 40 on the side surface of the support 45. In the examples shown in Figures 15 and 16, the support 45 has a first side surface 45s on the first direction DR1 side and a second side surface 45t on the second direction DR2 side. In the example shown in Figure 15, a first strain gauge 40a and a second strain gauge 40b are placed on the first side surface 45s. In the example shown in Figure 16, a third strain gauge 40c and a fourth strain gauge 40d are placed on the second side surface 45t.

[0120] (First group of fixing members B1) In the examples shown in Figures 12 to 16, the door device 1A includes a first group of fixing members B1 that fix the support 45 (more specifically, the bracket 450) to the door 2 (more specifically, the first frame 21 of the door 2). In the examples shown in Figures 12 and 13, the first group of fixing members B1 includes a first fixing member B1-1 (e.g., a first bolt) that fixes the first portion 45a of the support 45 (more specifically, the first portion of the bracket 450) to the door 2 (more specifically, the first frame 21 of the door 2). As illustrated in Figures 12 and 14, the first group of fixing members B1 may also include a second fixing member B1-2 (e.g., a second bolt) that fixes the fourth portion 45d of the support 45 (more specifically, the fourth portion of the bracket 450) to the door 2 (more specifically, the first frame 21 of the door 2).

[0121] (Second group of fixing members B2) In the examples shown in Figures 12 to 16, the door device 1A includes a second group of fixing members B2 for fixing the handle 3 to the support 45 (more specifically, the bracket 450). In the examples shown in Figures 12 and 13, the second group of fixing members B2 includes a third fixing member B2-1 (e.g., a third bolt) for fixing a first portion of the handle 3 (more specifically, the upper portion 31 of the handle 3) to a second portion 45b of the support 45 (more specifically, the second portion of the bracket 450). As illustrated in Figures 12 and 14, the second group of fixing members B2 may also include a fourth fixing member B2-2 (e.g., a fourth bolt) for fixing a second portion of the handle 3 (more specifically, the lower portion 33 of the handle 3) to a fifth portion 45e of the support 45 (more specifically, the fifth portion of the bracket 450).

[0122] In the example shown in Figure 13, a first through-hole 21h is formed in the door 2 (more specifically, the first frame 21 of the door 2) into which the third fixing member B2-1 is inserted. In the example shown in Figure 13, a gap (hereinafter referred to as "third gap G3") exists between the third fixing member B2-1 and the first through-hole 21h. Due to the presence of the third gap G3, the deformation of the support 45 is less likely to be hindered by the third fixing member B2-1. As illustrated in Figure 13, the door device 1A may also include a first collar 461 positioned between the third fixing member B2-1 and the first through-hole 21h. In the example shown in Figure 13, the third fixing member B2-1 is positioned to penetrate the first collar 461.

[0123] In the example shown in Figure 14, a second through-hole 21k is formed in the door 2 (more specifically, the first frame 21 of the door 2) into which the fourth fixing member B2-2 is inserted. In the example shown in Figure 14, a gap (hereinafter referred to as "fourth gap G4") exists between the fourth fixing member B2-2 and the second through-hole 21k. Due to the presence of the fourth gap G4, the deformation of the support 45 is less likely to be hindered by the fourth fixing member B2-2. As illustrated in Figure 14, the door device 1A may also include a second collar 462 positioned between the fourth fixing member B2-2 and the second through-hole 21k. In the example shown in Figure 14, the fourth fixing member B2-2 is positioned to penetrate the second collar 462.

[0124] (Strain gauge 40) In the example shown in Figure 17, the strain gauge 40 includes a first strain gauge 40a, a second strain gauge 40b, a third strain gauge 40c, and a fourth strain gauge 40d.

[0125] In the example shown in Figure 17, the first strain gauge 40a and the second strain gauge 40b are arranged along the longitudinal direction of the support 45. In the example shown in Figure 17, the third strain gauge 40c and the fourth strain gauge 40d are arranged along the longitudinal direction of the support 45. In the example shown in Figure 17, the first strain gauge 40a and the second strain gauge 40b are arranged on the first side surface 45s of the support 45, and the third strain gauge 40c and the fourth strain gauge 40d are arranged on the second side surface 45t of the support 45.

[0126] In the examples shown in Figures 15 and 17, when a first operating force in the first direction DR1 is applied to the handle 3, the first strain gauge 40a (more specifically, the electrical resistor 401a of the first strain gauge 40a) stretches (see Figure 18). Thus, the electrical resistance of the first strain gauge 40a increases.

[0127] In the examples shown in Figures 15 and 17, when a first operating force in the first direction DR1 is applied to the handle 3, the second strain gauge 40b (more specifically, the electrical resistor 401b of the second strain gauge 40b) stretches (see Figure 18). Thus, the electrical resistance of the second strain gauge 40b increases.

[0128] In the examples shown in Figures 16 and 17, when a first operating force in the first direction DR1 is applied to the handle 3, the third strain gauge 40c (more specifically, the electrical resistor 401c of the third strain gauge 40c) contracts (see Figure 19). In this way, the electrical resistance of the third strain gauge 40c decreases.

[0129] In the examples shown in Figures 16 and 17, when a first operating force in the first direction DR1 is applied to the handle 3, the fourth strain gauge 40d (more specifically, the electrical resistor 401d of the fourth strain gauge 40d) contracts (see Figure 19). In this way, the electrical resistance of the fourth strain gauge 40d decreases.

[0130] In the examples shown in Figures 15 and 17, when a second operating force in the second direction DR2 is applied to the handle 3, the first strain gauge 40a (more specifically, the electrical resistor 401a of the first strain gauge 40a) contracts. In the examples shown in Figures 15 and 17, when a second operating force in the second direction DR2 is applied to the handle 3, the second strain gauge 40b (more specifically, the electrical resistor 401b of the second strain gauge 40b) contracts.

[0131] In the examples shown in Figures 16 and 17, when a second operating force in the second direction DR2 is applied to the handle 3, the third strain gauge 40c (more specifically, the electrical resistor 401c of the third strain gauge 40c) stretches. In the examples shown in Figures 16 and 17, when a second operating force in the second direction DR2 is applied to the handle 3, the fourth strain gauge 40d (more specifically, the electrical resistor 401d of the fourth strain gauge 40d) stretches.

[0132] As illustrated in Figure 20, the first strain gauge 40a, the second strain gauge 40b, the third strain gauge 40c, and the fourth strain gauge 40d may be arranged in the bridge circuit 4. More specifically, in the example shown in Figure 20 (or in the examples shown in Figures 15 and 16), the first strain gauge 40a, the second strain gauge 40b, the third strain gauge 40c, and the fourth strain gauge 40d may be arranged in the support 45 to constitute a Wheatstone bridge circuit. In Figure 20, "E1" is the input voltage to the bridge circuit 4, and "E2" is the output voltage from the bridge circuit 4.

[0133] When the first strain gauge 40a, the second strain gauge 40b, the third strain gauge 40c, and the fourth strain gauge 40d constitute a Wheatstone bridge circuit, resistance changes caused by temperature changes are canceled out. Also, in the example shown in Figure 20 (or the examples shown in Figures 15 and 16), resistance changes caused by operating forces unrelated to the opening and closing operation of the door 2 (for example, the force of pulling the handle 3 towards the driver) are canceled out.

[0134] In the example shown in Figure 20, the control device 66 receives a signal corresponding to the output voltage E2 of the bridge circuit 4 as a signal S from the strain gauge 40. More specifically, the control device 66 receives a signal corresponding to the output voltage E2 from the bridge circuit 4 via the amplifier 65.

[0135] In the example shown in Figure 20 (or in the examples shown in Figures 15 and 16), when the handle 3 is operated in the first direction DR1, the first strain gauge 40a and the second strain gauge 40b extend, and the third strain gauge 40c and the fourth strain gauge 40d contract. As a result, the output voltage E2 of the bridge circuit 4 becomes a positive (or negative) value. On the other hand, when the handle 3 is operated in the second direction DR2, the first strain gauge 40a and the second strain gauge 40b contract, and the third strain gauge 40c and the fourth strain gauge 40d extend. As a result, the output voltage E2 of the bridge circuit 4 becomes a negative (or positive) value. Therefore, the control device 66 can determine whether the operating direction of the handle 3 is the first direction DR1 or the second direction DR2 based on the signal S from the strain gauges 40 (more specifically, based on the signal corresponding to the output voltage E2 of the bridge circuit 4).

[0136] In the example shown in Figure 20 (or in the examples shown in Figures 15 and 16), the absolute value of the output voltage E2 of the bridge circuit 4 increases as the first operating force of the handle 3 in the first direction DR1 increases. Therefore, the control device 66 can derive the magnitude of the first operating force of the handle 3 in the first direction DR1 based on the signal S from the strain gauge 40 (more specifically, based on the signal corresponding to the output voltage E2 of the bridge circuit 4).

[0137] In the example shown in Figure 20 (or in the examples shown in Figures 15 and 16), the absolute value of the output voltage E2 of the bridge circuit 4 increases as the second operating force of the handle 3 in the second direction DR2 increases. Therefore, the control device 66 can derive the magnitude of the second operating force of the handle 3 in the second direction DR2 based on the signal S from the strain gauge 40 (more specifically, based on the signal corresponding to the output voltage E2 of the bridge circuit 4).

[0138] In the example shown in Figure 20 (or in the examples shown in Figures 15 and 16), at least four strain gauges (40a, 40b, 40c, 40d) deform when the handle 3 is operated. Alternatively, as illustrated in Figure 21, only one strain gauge 40 (e.g., the first strain gauge 40a) may deform when the handle 3 is operated.

[0139] In the example shown in Figure 21, when the handle 3 is operated in the first direction DR1, the first strain gauge 40a compresses. As a result, the output voltage E2 of the bridge circuit 4 becomes a negative (or positive) value. On the other hand, when the handle 3 is operated in the second direction DR2, the first strain gauge 40a extends. As a result, the output voltage E2 of the bridge circuit 4 becomes a positive (or negative) value. Therefore, the control device 66 can determine whether the direction of operation of the handle 3 is the first direction DR1 or the second direction DR2 based on the signal S from the strain gauge 40 (more specifically, based on the signal corresponding to the output voltage E2 of the bridge circuit 4).

[0140] In the example shown in Figure 21, the absolute value of the output voltage E2 of the bridge circuit 4 increases as the first operating force of the handle 3 in the first direction DR1 increases. Therefore, the control device 66 can derive the magnitude of the first operating force of the handle 3 in the first direction DR1 based on the signal S from the strain gauge 40 (more specifically, based on the signal corresponding to the output voltage E2 of the bridge circuit 4).

[0141] In the example shown in Figure 21, the absolute value of the output voltage E2 of the bridge circuit 4 increases as the second operating force of the handle 3 in the second direction DR2 increases. Therefore, the control device 66 can derive the magnitude of the second operating force of the handle 3 in the second direction DR2 based on the signal S from the strain gauge 40 (more specifically, based on the signal corresponding to the output voltage E2 of the bridge circuit 4).

[0142] In the example shown in Figure 21, one of the four resistors in the bridge circuit 4 is a strain gauge 40, and three of the four resistors in the bridge circuit 4 are fixed resistors 42 (in other words, resistors whose electrical resistance does not substantially change). Alternatively, two of the four resistors in the bridge circuit 4 may be strain gauges, or three of the four resistors in the bridge circuit 4 may be strain gauges. Also, if the bridge circuit 4 includes multiple strain gauges, at least one of the multiple strain gauges may be a dummy strain gauge. In the example shown in Figure 22, one of the four resistors in the bridge circuit 4 is a strain gauge 40 that detects the operation of the handle 3 (for example, a first strain gauge 40a), and one of the four resistors in the bridge circuit 4 is a dummy strain gauge 41.

[0143] In the examples shown in Figures 20 to 22, when the control device 66 determines, based on the signal S from the strain gauge 40 (more specifically, based on the signal corresponding to the output voltage E2 of the bridge circuit 4), that the handle 3 is receiving a first operating force exceeding a first lower limit threshold SL1 in the first direction DR1, the control device 66 transmits a first group of control commands to the regulator 61 and the directional control valve 7 so that the air cylinder 5 applies a first assist force to the door 2 in the first direction DR1. The first group of control commands includes the first control signal C1 sent to the regulator 61.

[0144] In the examples shown in Figures 20 to 22, when the control device 66 determines, based on the signal S from the strain gauge 40 (more specifically, based on the signal corresponding to the output voltage E2 of the bridge circuit 4), that the handle 3 is receiving a second operating force in the second direction DR2 that exceeds the second lower limit threshold SL2, the control device 66 transmits a second group of control commands to the regulator 61 and the directional control valve 7 so that the air cylinder 5 applies a second assist force to the door 2 in the second direction DR2. The second group of control commands includes the second control signal C2 sent to the regulator 61.

[0145] (Second Embodiment) The door device 1B for a machine tool in the second embodiment will be described with reference to Figures 23 to 25. Figures 23 and 24 are schematic diagrams showing the door device 1B for a machine tool in the second embodiment. Figure 25 is a schematic diagram showing an example of the arrangement of the movable pulley 86 and / or air cylinder 5.

[0146] The door device 1B for the machine tool in the second embodiment differs from the door device 1A for the machine tool in the first embodiment in that it includes a movable pulley 86. In other respects, the door device 1B for the machine tool in the second embodiment is the same as the door device 1A for the machine tool in the first embodiment.

[0147] The second embodiment will be described primarily in terms of its differences from the first embodiment. On the other hand, in the second embodiment, repetitive explanations of matters already explained in the first embodiment will be omitted. Therefore, it goes without saying that even if not explicitly explained in the second embodiment, matters already explained in the first embodiment can be applied to the second embodiment.

[0148] As illustrated in Figure 23, the door device 1B for a machine tool in the second embodiment includes: (1) a door 2 that can slide in a first direction DR1 so as to open at least a portion of the opening OP of the machine tool, and can slide in a second direction DR2 opposite to the first direction DR1 so as to close at least a portion of the opening OP; (2) a handle 3 positioned on the door 2; (3) a strain gauge 40 for detecting the operation of the handle 3; (4) an air cylinder 5 for providing an assisting force to the door 2; (5) an air supply passage FP connecting the air cylinder 5 and an air supply source 91; (6) a regulator 61 for adjusting the pressure of the air flowing through the air supply passage FP; and (7) a control device 66 for controlling the regulator 61 based on a signal S from the strain gauge 40.

[0149] Therefore, the door device 1B for machine tools in the second embodiment provides the same effects as the door device 1A for machine tools in the first embodiment.

[0150] In the examples shown in Figures 23 and 24, the air cylinder 5 has a piston 54 driven by air supplied to the first chamber 51. More specifically, the air cylinder 5 has a first chamber 51, a second chamber 53, and a piston 54 positioned between the first chamber 51 and the second chamber 53.

[0151] In the example shown in Figures 23 and 24, the door device 1B includes a movable pulley 86 that converts the first travel amount of the door 2 into a second travel amount of the piston 54 which is smaller than the first travel amount. The second travel amount is, for example, half of the first travel amount.

[0152] In the examples shown in Figures 23 and 24, the door device 1B is equipped with a movable pulley 86, which allows the travel stroke of the piston 54 to be reduced compared to the travel stroke of the door 2. Therefore, the length of the air cylinder 5 can be reduced.

[0153] Next, with reference to Figures 23 to 25, optional additional configurations that can be adopted in the door device 1B for machine tools in the second embodiment will be described.

[0154] (First movable pulley 86A) In the example shown in Figures 23 and 24, the movable pulley 86 includes a first movable pulley 86A. The first movable pulley 86A is supported by a first rod 55A (more specifically, the first end 551A of the first rod 55A) so as to be rotatable around a first pivot axis AX1. The second end of the first rod 55A is connected to, for example, a piston 54.

[0155] As illustrated in Figure 23, we assume that the state of the directional control valve 7 is the first state J1. In the example shown in Figure 23, the first chamber 51 is fluidly connected to the air supply source 91. In this case, when air is supplied to the first chamber 51, a first force F1 is applied to the piston 54, the first rod 55A, and the first movable pulley 86A in the first direction DR1.

[0156] In the example shown in Figure 23, the door device 1B includes a flexible member 87 guided by a first movable pulley 86A. The door 2 is directly or indirectly connected to the flexible member 87. In this case, when a first force F1 is applied to the first movable pulley 86A in a first direction DR1, the flexible member 87 applies a first assist force to the door 2 equal to half the magnitude of the first force F1.

[0157] Assume that the door 2 moves by a first amount in the first direction DR1 due to the combined force of the first assisting force and the operator's operating force. In this case, the first movable pulley 86A, the first rod 55A, and the piston 54 move by a second amount in the first direction DR1, which is half the size of the first amount of movement.

[0158] The flexible member 87 may be a linear material such as a wire or cable, or a strip material such as a belt. In the example shown in Figure 23, the first end 87a of the flexible member 87 is connected to the main body 50 (in other words, the cylinder portion) of the air cylinder 5. Alternatively, the first end 87a of the flexible member 87 may be connected to the wall 110.

[0159] (Second movable pulley 86B) In the example shown in Figure 24, the movable pulley 86 includes a second movable pulley 86B. The second movable pulley 86B is supported by a second rod 55B (more specifically, the first end 551B of the second rod 55B) so as to be rotatable around the second pivot axis AX2. The second end of the second rod 55B is connected, for example, to a piston 54.

[0160] As illustrated in Figure 24, we assume that the state of the directional control valve 7 is the second state J2. In the example shown in Figure 24, the second chamber 53 is fluidly connected to the air supply source 91. In this case, when air is supplied to the second chamber 53, a second force F2 is applied to the piston 54, the second rod 55B, and the second movable pulley 86B in the second direction DR2.

[0161] In the example shown in Figure 24, the door device 1B includes a flexible member 87 guided by a second movable pulley 86B. The door 2 is directly or indirectly connected to the flexible member 87. In this case, when a second force F2 is applied to the second movable pulley 86B in a second direction DR2, the flexible member 87 applies a second assist force to the door 2 equal to half the magnitude of the second force F2.

[0162] Assume that the door 2 moves by a third amount in the second direction DR2 due to the combined force of the second assisting force and the operator's operating force. In this case, the second movable pulley 86B, the second rod 55B, and the piston 54 move by a fourth amount in the second direction DR2, which is half the size of the third amount of movement.

[0163] In the example shown in Figure 24, the second end 87b of the flexible member 87 is connected to the main body 50 of the air cylinder 5. Alternatively, the second end 87b of the flexible member 87 may be connected to the wall 110.

[0164] Furthermore, if a winding device is provided that winds up excess wire and unwinds insufficient wire, the second movable pulley 86B may be omitted. Alternatively, the second movable pulley 86B may be replaced with a fixed pulley.

[0165] In the examples shown in Figures 23 and 24, the air cylinder 5 is a double-rod cylinder. More specifically, the air cylinder 5 comprises a first rod 55A projecting in a first direction DR1 from a first end of the main body 50, and a second rod 55B projecting in a second direction DR2 from a second end of the main body 50. A first movable pulley 86A is positioned at the tip of the first rod 55A, and a second movable pulley 86B is positioned at the tip of the second rod 55B. In the examples shown in Figures 23 and 24, the flexible member 87 is guided by both the first movable pulley 86A positioned at the tip of the first rod 55A and the second movable pulley 86B positioned at the tip of the second rod 55B.

[0166] (Arrangement of movable pulleys 86) In the example shown in Figure 25, the axis of rotation of the movable pulleys 86 is parallel to the vertical direction. More specifically, the first axis of rotation AX1 of the first movable pulley 86A is parallel to the vertical direction, and the second axis of rotation AX2 of the second movable pulley 86B is parallel to the vertical direction. In this case, the height of the movable pulleys 86 can be made compact, and the height of the entire mechanism that provides the assisting force can also be made compact.

[0167] In the example shown in Figure 25, a movable pulley 86 is positioned on the ceiling portion 111 of the machine tool (more specifically, on the upper surface 111u of the ceiling portion 111). In this case, because the axis of rotation of the movable pulley 86 is parallel to the vertical direction, the overall height of the machine tool can be made more compact.

[0168] (Arrangement of Air Cylinder 5) In the example shown in Figure 25, the air cylinder 5 is arranged on the ceiling portion 111 of the machine tool (more specifically, on the upper surface 111u of the ceiling portion 111). In this case, there is no need to increase the size of the machine tool in plan view by adding the air cylinder 5. Also, it is easy to add a mechanism (such as the air cylinder 5) that provides assisting force to an existing machine tool. In the example shown in Figure 25, the main body portion 50 of the air cylinder 5 (in other words, the cylinder portion) is fixed to the ceiling portion 111. The arrangement of the air cylinder 5 in Figure 25 may also be adopted in the first embodiment.

[0169] In the example shown in Figure 25, the main body 50 of the air cylinder 5 is positioned so as not to overlap with the movable pulley 86 in a plan view. More specifically, the main body 50 of the air cylinder 5 and the movable pulley 86 (more specifically, the first movable pulley 86A and the second movable pulley 86B) are arranged along a single horizontal plane. In this case, the overall height of the mechanism that provides the assisting force can be made more compact. In the example shown in Figure 25, the first movable pulley 86A, the main body 50 of the air cylinder 5, and the second movable pulley 86B are arranged on a single straight line parallel to the horizontal plane.

[0170] (First connecting member 88) The door device 1B has a first connecting member 88 that connects the door 2 and the flexible member 87. In the example shown in Figure 25, the first connecting member 88 is positioned so as not to overlap with the air cylinder 5 in a plan view. More specifically, the air cylinder 5 and the first connecting member 88 are positioned along a single horizontal plane. In this case, the height of the entire mechanism that provides the assisting force can be made compact. In the example shown in Figure 25, when the direction from the back of the machine tool toward the opening OP of the machine tool is defined as the fourth direction DR4, the first connecting member 88 is positioned on the fourth direction DR4 side of the air cylinder 5.

[0171] (Second connecting member 89) The door device 1B may have at least one second connecting member 89 that connects the ceiling portion 111 and the flexible member 87. In the example shown in Figure 25, the air cylinder 5 and at least one second connecting member 89 are arranged along one horizontal plane. In the example shown in Figure 25, there are two second connecting members 89, but there may be one or three or more second connecting members 89. Also, if the flexible member 87 is an endless member, the second connecting member 89 may be omitted.

[0172] (Door 2) In the example shown in Figure 25, there is one door 2. Alternatively, there may be two or more doors 2.

[0173] In the example shown in Figure 25, the opening OP includes a first opening OP1 formed in the front wall 112 of the machine tool and a second opening OP2 formed in the ceiling portion 111 of the machine tool. Also in the example shown in Figure 25, the door 2 has a first plate portion 23 that can close the first opening OP1 in the front wall 112 and a second plate portion 24 that can close the second opening OP2 in the ceiling portion 111. In the example shown in Figure 25, the door 2 has a substantially L-shape in a cross section perpendicular to the first direction DR1. Note that in the first or second embodiment, the shape of the door 2 is not limited to the above example and is arbitrary.

[0174] (Support member 95) The door device 1B may have a support member 95 that supports the air cylinder 5, the movable pulley 86, and the first connecting member 88. In this case, by attaching the support member 95 to the ceiling portion 111, the air cylinder 5, the movable pulley 86, and the first connecting member 88 can be arranged on the ceiling portion 111.

[0175] (Third Embodiment) The machine tool 100 in the third embodiment will be described with reference to Figures 1 to 29. Figure 26 is a schematic perspective view showing the machine tool 100 in the third embodiment. Figure 27 is a schematic diagram showing how the numerical control device 15 can control the controlled device. Figure 28 is a schematic diagram showing an example of the first image IM1 displayed on the display 157. Figure 29 is a schematic diagram showing another example of the first image IM1 displayed on the display 157.

[0176] The third embodiment will primarily describe the differences from the first and second embodiments. On the other hand, in the third embodiment, repetitive explanations of matters already described in the first or second embodiment will be omitted. Therefore, it goes without saying that even if not explicitly explained in the third embodiment, matters already described in the first or second embodiment can be applied to the third embodiment.

[0177] As illustrated in Figure 26, the machine tool 100 in the third embodiment includes a workpiece support device 12, a machining head 13, a moving device 14, a numerical control device 15, a wall 110 having an opening OP, and a door device 1. The machine tool 100 may be a lathe, a machining center, or a multi-tasking machine capable of performing multiple types of machining.

[0178] The door device 1 may be the door device 1A in the first embodiment, the door device 1B in the second embodiment, or any other door device. The door device 1 includes (1) a door 2 that is slidable in a first direction DR1 so as to open at least a portion of the opening OP, and slidable in a second direction DR2 opposite to the first direction DR1 so as to close at least a portion of the opening OP; (2) a handle 3 positioned on the door 2; (3) a strain gauge 40 for detecting the operation of the handle 3; (4) an air cylinder 5 for providing an assisting force to the door 2; (5) an air supply passage FP connecting the air cylinder 5 and an air supply source 91; (6) a regulator 61 for adjusting the pressure of the air flowing through the air supply passage FP; and (7) a control device 66 for controlling the regulator 61 based on a signal S from the strain gauge 40.

[0179] The workpiece support device 12 supports the workpiece. The workpiece support device 12 may include a chuck 121 for holding the workpiece, or it may include a table for supporting the workpiece. The workpiece support device 12 may also include a workpiece rotating device 123 for rotating the workpiece. The workpiece rotating device 123 may rotate the chuck 121 for holding the workpiece.

[0180] The machining head 13 is capable of holding a tool T for machining a workpiece. The machining head 13 may also be equipped with a rotary drive device 133 for rotating the tool T.

[0181] The moving device 14 moves the machining head 13 relative to the workpiece support device 12.

[0182] The numerical control device 15 controls the moving device 14. More specifically, the numerical control device 15 transmits a movement command to the moving device 14, and the moving device 14, upon receiving the movement command, moves the machining head 13 relative to the workpiece support device 12.

[0183] Additionally, the numerical control device 15 may control the workpiece rotating device 123. More specifically, the numerical control device 15 transmits a first rotation command to the workpiece rotating device 123, and the workpiece rotating device 123, upon receiving the first rotation command, rotates the workpiece. Alternatively, or additionally, the numerical control device 15 may control the rotary drive device 133. More specifically, the numerical control device 15 transmits a second rotation command to the rotary drive device 133, and the rotary drive device 133, upon receiving the second rotation command, rotates the tool T.

[0184] The wall 110 may define a processing area. In the example shown in Figure 25, a workpiece can be brought into the processing area through an opening OP in the wall 110. The wall 110 may include a front wall 112. In the example shown in Figure 25, the opening OP is formed in the front wall 112.

[0185] (Optional Additional Configurations) Next, with reference to Figures 1 to 29, optional additional configurations that can be adopted in the machine tool 100 in the third embodiment will be described.

[0186] (Numerical Control Device 15) In the example shown in Figure 27, the numerical control device 15 includes a hardware processor 150 (hereinafter simply referred to as "processor 150"), a storage device 152 (in other words, memory), a communication circuit 154, an input device 156, and a display 157. The processor 150, the storage device 152, the communication circuit 154, the input device 156, and the display 157 are connected to each other via a bus 158. In the example shown in Figure 27, the input device 156 includes a touch panel 156t on the display 157. In other words, the display 157 is a display with a touch panel 156t. The input device 156 may include buttons, switches, levers, pointing devices, and / or a keyboard.

[0187] The storage device 152 is a storage medium readable by the processor 150 of the numerical control device 15. The storage device 152 may be, for example, a non-volatile or volatile semiconductor memory such as RAM, ROM, or flash memory, or it may be a magnetic disk or other type of memory.

[0188] The storage device 152 stores data DA and the machining program PM. The processor 150 of the numerical control device 15 executes the machining program PM stored in the storage device 152, thereby generating control commands. The communication circuit 154 then transmits these control commands to the controlled equipment (more specifically, the moving device 14, the workpiece rotating device 123, the rotary drive device 133, etc.). In this way, by the processor 150 executing the machining program PM, the numerical control device 15 can control the controlled equipment (more specifically, the moving device 14, the workpiece rotating device 123, the rotary drive device 133, etc.).

[0189] The storage device 152 may store a parameter change program PT that modifies the first group of parameters PA and the second group of parameters PB stored in the memory 661 of the control device 66. The numerical control device 15 (more specifically, the processor 150 of the numerical control device 15) modifies the first group of parameters PA and the second group of parameters PB stored in the memory 661 of the control device 66 based on user input by executing the parameter change program PT.

[0190] In the example shown in Figure 28, the numerical control device 15 can display an image (hereinafter referred to as "first image IM1") on the display 157 that accepts user input for changing the first group of parameters PA described above.

[0191] More specifically, the numerical control device 15 executes a parameter change program PT stored in the storage device 152, thereby displaying a first image IM1 on the display 157 that accepts user input for changing the first group of parameters PA described above. The first image IM1 may also include an image that accepts user input for changing the second group of parameters PB described above.

[0192] In the example shown in Figure 28, the first image IM1 includes a first button BN1 (more specifically, an image of a plus button) that increases the first parameter PA1 which defines the first lower threshold SL1 (see Figure 8). After the first button BN1 is pressed or clicked, the approval button BP is pressed or clicked, causing the numerical control device 15 to increase the value of the first parameter PA1 stored in the memory 661 of the control device 66. In the example shown in Figure 28, after the first button BN1 is pressed or clicked, the approval button BP is pressed or clicked, causing the numerical control device 15 to increase both the value of the first parameter PA1 stored in the memory 661 of the control device 66 and the value of the fifth parameter PB1 stored in the memory 661 of the control device 66. In other words, the first button BN1 may be a button that increases the first parameter PA1 which defines the first lower threshold SL1 (see Figure 8) and the fifth parameter PB1 which defines the second lower threshold SL2 (see Figure 8).

[0193] In the example shown in Figure 28, the first image IM1 includes a second button BN2 (more specifically, an image of a minus button) that decreases the first parameter PA1 which defines the first lower threshold SL1 (see Figure 8). After the second button BN2 is pressed or clicked, the approval button BP is pressed or clicked, causing the numerical control device 15 to decrease the value of the first parameter PA1 stored in the memory 661 of the control device 66. In the example shown in Figure 28, after the second button BN2 is pressed or clicked, the approval button BP is pressed or clicked, causing the numerical control device 15 to decrease both the value of the first parameter PA1 stored in the memory 661 of the control device 66 and the value of the fifth parameter PB1 stored in the memory 661 of the control device 66. In other words, the second button BN2 may be a button that decreases the first parameter PA1 which defines the first lower threshold SL1 (see Figure 8) and the fifth parameter PB1 which defines the second lower threshold SL2 (see Figure 8).

[0194] Alternatively, or additionally, as illustrated in Figure 29, the first image IM1 may include a first specification field NY1 for specifying the value of the first parameter PA1 that defines the first lower threshold SL1 (see Figure 8). After a value is entered in the first specification field NY1, the numerical control device 15 may change the value of the first parameter PA1 stored in the memory 661 of the control device 66 to the value corresponding to the value entered in the first specification field NY1 when the approval button BP is pressed or clicked. In the example shown in Figure 29, after a value is entered in the first specification field NY1, the numerical control device 15 may change the value of the first parameter PA1 stored in the memory 661 of the control device 66 to the value corresponding to the value entered in the first specification field NY1, and also change the value of the fifth parameter PB1 stored in the memory 661 of the control device 66 to the value corresponding to the value entered in the first specification field NY1 when the approval button BP is pressed or clicked.

[0195] In the example shown in Figure 28, the first image IM1 includes a change button BM (more specifically, an image of the change button) that changes the second parameter PA2 which defines the first increase rate IN1 (see Figure 8). After the change button BM is pressed or clicked, the approval button BP is pressed or clicked, causing the numerical control device 15 to change the value of the second parameter PA2 stored in the memory 661 of the control device 66.

[0196] Alternatively, or additionally, as illustrated in Figure 29, the first image IM1 may include a second specification field NY2 for specifying the value of the second parameter PA2 that defines the first increase rate IN1 (see Figure 8). After a value is entered in the second specification field NY2, when the approval button BP is pressed or clicked, the numerical control device 15 changes the value of the second parameter PA2 stored in the memory 661 of the control device 66 to the value corresponding to the value entered in the second specification field NY2. In the example shown in Figure 29, after a value is entered in the second specification field NY2, when the approval button BP is pressed or clicked, the numerical control device 15 changes the value of the second parameter PA2 stored in the memory 661 of the control device 66 to the value corresponding to the value entered in the second specification field NY2, and may also change the value of the sixth parameter PB2 stored in the memory 661 of the control device 66 to another value corresponding to the value entered in the second specification field NY2.

[0197] Note that the graph showing the first growth rate IN1 (see Figure 8) and the graph displayed in the first image IM1 use different unit systems. Therefore, it is preferable that the control device 66, which executes the parameter change program PT, is configured to automatically derive the change value of the second parameter PA2 and / or the change value of the sixth parameter PB2 based on user input, including the operation of the change button BM or input into the second specification field NY2. When the change value of the second parameter PA2 and the change value of the sixth parameter PB2 are derived, it is preferable that the numerical control device 15 derives the change value of the second parameter PA2 and the change value of the sixth parameter PB2 by considering the difference between the area of ​​the first pressure-receiving surface 54a of the piston 54 and the area of ​​the second pressure-receiving surface 54b of the piston 54.

[0198] In the example shown in Figure 28, the first image IM1 includes a third button BN3 (more specifically, an image of a plus button) that increases the third parameter PA3 which defines the first maximum value MA1 (see Figure 8). After the third button BN3 is pressed or clicked, the approval button BP is pressed or clicked, causing the numerical control device 15 to increase the value of the third parameter PA3 stored in the memory 661 of the control device 66. In the example shown in Figure 28, after the third button BN3 is pressed or clicked, the approval button BP is pressed or clicked, causing the numerical control device 15 to increase both the value of the third parameter PA3 stored in the memory 661 of the control device 66 and the value of the seventh parameter PB3 stored in the memory 661 of the control device 66. In other words, the third button BN3 may be a button that increases the third parameter PA3 which defines the first maximum value MA1 (see Figure 8) and the seventh parameter PB3 which defines the second maximum value MA2 (see Figure 8).

[0199] In the example shown in Figure 28, the first image IM1 includes a fourth button BN4 (more specifically, an image of a minus button) that decreases the third parameter PA3 which defines the first maximum value MA1 (see Figure 8). After the fourth button BN4 is pressed or clicked, the approval button BP is pressed or clicked, causing the numerical control device 15 to decrease the value of the third parameter PA3 stored in the memory 661 of the control device 66. In the example shown in Figure 28, after the fourth button BN4 is pressed or clicked, the approval button BP is pressed or clicked, causing the numerical control device 15 to decrease both the value of the third parameter PA3 stored in the memory 661 of the control device 66 and the value of the seventh parameter PB3 stored in the memory 661 of the control device 66. In other words, the fourth button BN4 may be a button that decreases the third parameter PA3 which defines the first maximum value MA1 (see Figure 8) and the seventh parameter PB3 which defines the second maximum value MA2 (see Figure 8).

[0200] Alternatively, or additionally, as illustrated in Figure 29, the first image IM1 may include a third specification field NY3 for specifying the value of the third parameter PA3 that defines the first maximum value MA1 (see Figure 8). After a value is entered in the third specification field NY3, when the approval button BP is pressed or clicked, the numerical control device 15 changes the value of the third parameter PA3 stored in the memory 661 of the control device 66 to the value corresponding to the value entered in the third specification field NY3. In the example shown in Figure 29, after a value is entered in the third specification field NY3, when the approval button BP is pressed or clicked, the numerical control device 15 changes the value of the third parameter PA3 stored in the memory 661 of the control device 66 to the value corresponding to the value entered in the third specification field NY3, and may also change the value of the seventh parameter PB3 stored in the memory 661 of the control device 66 to another value corresponding to the value entered in the third specification field NY3.

[0201] Note that the graph showing the first maximum value MA1 (see Figure 8) and the graph displayed in the first image IM1 use different units. Therefore, it is preferable that the control device 66 that executes the parameter change program PT is configured to automatically derive the change value of the third parameter PA3 based on the operation of the third button BN3 or the fourth button BN4, or user input including input into the third specification field NY3.

[0202] The control device 66 may be configured to automatically derive the value of the third parameter PA3 and the value of the seventh parameter PB3 based on the operation of the third button BN3 or the fourth button BN4, or user input including input into the third designation field NY3. When the value of the third parameter PA3 and the value of the seventh parameter PB3 are to be derived, it is preferable that the numerical control device 15 derives the value of the third parameter PA3 and the value of the seventh parameter PB3 by considering the difference between the area of ​​the first pressure-receiving surface 54a of the piston 54 and the area of ​​the second pressure-receiving surface 54b of the piston 54.

[0203] In the example shown in Figure 28, the first image IM1 includes a fifth button BN5 (more specifically, an image of a plus button) that increases the fourth parameter PA4 which defines the first upper limit threshold SH1 (see Figure 8). After the fifth button BN5 is pressed or clicked, the approval button BP is pressed or clicked, causing the numerical control device 15 to increase the value of the fourth parameter PA4 stored in the memory 661 of the control device 66. In the example shown in Figure 28, after the fifth button BN5 is pressed or clicked, the approval button BP is pressed or clicked, causing the numerical control device 15 to increase both the value of the fourth parameter PA4 stored in the memory 661 of the control device 66 and the value of the eighth parameter PB4 stored in the memory 661 of the control device 66. In other words, the fifth button BN5 may be a button that increases the fourth parameter PA4, which defines the first upper limit threshold SH1 (see Figure 8), and the eighth parameter PB4, which defines the second upper limit threshold SH2 (see Figure 8).

[0204] In the example shown in Figure 28, the first image IM1 includes a sixth button BN6 (more specifically, an image of a minus button) that reduces the fourth parameter PA4 which defines the first upper limit threshold SH1 (see Figure 8). After the sixth button BN6 is pressed or clicked, the approval button BP is pressed or clicked, causing the numerical control device 15 to reduce the value of the fourth parameter PA4 stored in the memory 661 of the control device 66. In the example shown in Figure 28, after the sixth button BN6 is pressed or clicked, the approval button BP is pressed or clicked, causing the numerical control device 15 to reduce both the value of the fourth parameter PA4 stored in the memory 661 of the control device 66 and the value of the eighth parameter PB4 stored in the memory 661 of the control device 66. In other words, the sixth button BN6 may be a button that decreases the fourth parameter PA4 which defines the first upper limit threshold SH1 (see Figure 8) and the eighth parameter PB4 which defines the second upper limit threshold SH2 (see Figure 8).

[0205] Alternatively, or additionally, as illustrated in Figure 29, the first image IM1 may include a fourth specification field NY4 for specifying the value of the fourth parameter PA4 that defines the first upper limit threshold SH1 (see Figure 8). After a value is entered in the fourth specification field NY4, when the approval button BP is pressed or clicked, the numerical control device 15 changes the value of the fourth parameter PA4 stored in the memory 661 of the control device 66 to the value corresponding to the value entered in the fourth specification field NY4. After a value is entered in the fourth specification field NY4, when the approval button BP is pressed or clicked, the numerical control device 15 may change the value of the fourth parameter PA4 stored in the memory 661 of the control device 66 to the value corresponding to the value entered in the fourth specification field NY4, and also change the value of the eighth parameter PB4 stored in the memory 661 of the control device 66 to the value corresponding to the value entered in the fourth specification field NY4.

[0206] In the example shown in Figure 27, the control device 66 is located outside the numerical control device 15, but the control device 66 may also be integrally located within the numerical control device 15.

[0207] In the third embodiment, the first group of parameters PA that can be changed using the numerical control device 15 are not limited to the first parameter PA1, the second parameter PA2, the third parameter PA3, and the fourth parameter PA4 described above. At least one of the first parameter PA1, the second parameter PA2, the third parameter PA3, and the fourth parameter PA4 described above may be a parameter that cannot be changed using the numerical control device 15. In addition, other parameters included in the first group of parameters PA may be changeable using the numerical control device 15.

[0208] In the third embodiment, the parameters PB of the second group described above, which can be changed using the numerical control device 15, are not limited to the fifth parameter PB1, the sixth parameter PB2, the seventh parameter PB3, and the eighth parameter PB4 described above. At least one of the fifth parameter PB1, the sixth parameter PB2, the seventh parameter PB3, and the eighth parameter PB4 described above may be a parameter that cannot be changed using the numerical control device 15. Alternatively, other parameters included in the parameters PB of the second group may be changed using the numerical control device 15.

[0209] Changes to the first group parameter PA (or the second group parameter PB) described above are permitted only within a predetermined range. In the examples shown in Figures 28 and 29, the range indicated by the hatched area is outside the predetermined range.

[0210] In the examples shown in Figures 28 and 29, both the first group of parameters PA and the second group of parameters PB are changed by manipulating the first image IM1. Alternatively, images for changing the first group of parameters PA and images for changing the second group of parameters PB may be provided separately.

[0211] The present invention is not limited to the embodiments or modifications described above, and it is clear that each embodiment or modification can be appropriately modified or changed within the scope of the technical concept of the present invention. Furthermore, the various technologies used in each embodiment or modification can be applied to other embodiments or other modifications, as long as no technical inconsistencies arise. In addition, any optional additional configurations in each embodiment or modification can be omitted as appropriate.

[0212] 1, 1A, 1B... Door device, 2... Door, 2u... Top, 2w... Bottom, 3... Handle, 4... Bridge circuit, 5... Air cylinder, 7... Directional control valve, 12... Workpiece support device, 13... Machining head, 14... Moving device, 15... Numerical control device, 21... First frame, 21h... First through hole, 21k... Second through hole, 23... First plate, 24... Second plate, 31... Upper part, 33... Lower part, 35... Middle part, 40... Strain gauge, 40a... First strain gauge, 40b... Second strain gauge, 40c... Third strain gauge, 40d... Fourth strain gauge, 41... Dummy strain gauge, 42... Fixed resistor, 45... Support body, 45a...First part of the support body, 45b...Second part of the support body, 45c...Third part of the support body, 45c-1...First side of the third part, 45c-2...Second side of the third part, 45d...Fourth part of the support body, 45e...Fifth part of the support body, 45f...Sixth part of the support body, 45f-1...First side of the sixth part, 45f-2...Second side of the sixth part, 45s...First side of the support body, 45t...Second side of the support body, 50...Main body of the air cylinder, 51...First chamber, 53...Second chamber, 54...Piston, 54a...First pressure receiving surface, 54b...Second pressure receiving surface, 55...Rod, 55A...First rod, 55B...Second 2 rods, 61...regulator, 61a...electro-pneumatic regulator, 62...pressure sensor, 63...valve, 64...controller, 65...amplifier, 66...control device, 86...movable pulley, 86A...first movable pulley, 86B...second movable pulley, 87...flexible member, 87a...first end, 87b...second end, 88...first connecting member, 89...second connecting member, 91...air supply source, 95...support member, 100...machine tool, 110...wall, 111...ceiling, 111u...top surface, 112...front wall, 121...chuck, 123...workpiece rotating device, 133...rotary drive device, 150...processor, 152...memory device, 154...communication circuit, 156...input device, 156t...touch panel, 157...display, 158...bus, 211...front surface of the first frame, 213...back surface of the first frame, 401, 401a, 401b, 401c, 401d...electrical resistor, 450...bracket, 451c...thinning region, 451f...thinning region, 452c...first hole, 452f...second hole, 453c...non-thinning region, 453f...non-thinning region, 461...first color, 462...second color, 551A...first end of the first rod, 551B...first end of the second rod, 661...memory, 662...processorAX1...First rotation axis, AX2...Second rotation axis, B1...First group fixing member, B1-1...First fixing member, B1-2...Second fixing member, B2...Second group fixing member, B2-1...Third fixing member, B2-2...Fourth fixing member, BM...Change button, BN1...First button, BN2...Second button, BN3...Third button, BN4...Fourth button, BN5...Fifth button, BN6...Sixth button, BP...Approval button, C...Control signal, C1...First control signal, C2...Second control signal, CM1...First control command, CM2...Second control command, D...Atmospheric outlet, D1...First atmospheric outlet Opening, D2...Second atmospheric opening, DA...Data, DR1...First direction, DR2...Second direction, DR3...Third direction, DR4...Fourth direction, E1...Input voltage to bridge circuit, E2...Output voltage of bridge circuit, F1...First force, F2...Second force, F3...Third flow path, F4...Fourth flow path, FP...Air supply flow path, FP1...First flow path, FP2...Second flow path, G1...First gap, G2...Second gap, G3...Third gap, G4...Fourth gap, IM1...First image, IN1...First growth rate, IN2...Second growth rate, IN3...Third growth rate, IN4...Fourth growth rate, J0...Difference Fort state, J1...First state, J2...Second state, MA1...First maximum value, MA2...Second maximum value, NY1...First designated field, NY2...Second designated field, NY3...Third designated field, NY4...Fourth designated field, OP...Opening, OP1...First opening, OP2...Second opening, PA...Parameters of the first group, PA1...First parameter, PA2...Second parameter, PA3...Third parameter, PA4...Fourth parameter, PB...Parameters of the second group, PB1...Fifth parameter, PB2...Sixth parameter, PB3...Seventh parameter, PB4...Eighth parameter, PG...P Program, PM... Machining program, PT... Parameter change program, Q1... First position, Q2... Second position, Q3... Any position between the first and second positions, RA1... First range, RA2... Second range, RA3... Third range, RA4... Fourth range, S... Signal, SD... Detection signal, SH1... First upper threshold, SH2... Second upper threshold, SL1... First lower threshold, SL2... Second lower threshold, SP... Space, T... Tool, T1... First target pressure, T2... Second target pressure, U... Unit, U1... First unit, U2... Second unit, V1... First value, V2... Second value

Claims

1. A door device for a machine tool comprising: a door that can slide in a first direction so as to open at least a portion of the opening of the machine tool, and a door that can slide in a second direction opposite to the first direction so as to close at least the portion of the opening; a handle disposed on the door; a strain gauge for detecting the operation of the handle; an air cylinder for providing an assisting force to the door; an air supply passage connecting the air cylinder and an air supply source; a regulator for adjusting the pressure of the air flowing through the air supply passage; and a control device for controlling the regulator based on a signal from the strain gauge.

2. The door device for a machine tool according to claim 1, wherein the regulator adjusts the pressure based on an electrical signal or optical signal received from the control device.

3. The door device for a machine tool according to claim 1 or 2, further comprising a directional control valve for switching the direction of the assisting force between a first direction and a second direction, wherein the control device controls the directional control valve based on the signal from the strain gauge.

4. The door device for a machine tool according to claim 3, wherein the directional control valve is positioned between the regulator and the air cylinder in a direction along the air supply passage.

5. The door device for a machine tool according to claim 3 or 4, wherein a parameter defining the change in the magnitude of the first assist force in the first direction in response to a change in the magnitude of the first operating force acting on the handle in the first direction is changeable.

6. When the handle is operated in the first direction, the control device transmits a first control command to the directional control valve, and the directional control valve, upon receiving the first control command, fluidly connects the first chamber of the air cylinder and the regulator; when the handle is operated in the second direction, the control device transmits a second control command to the directional control valve, and the directional control valve, upon receiving the second control command, fluidly connects the second chamber of the air cylinder and the regulator; and when the state of the directional control valve is the default state, each of the first chamber and the second chamber is fluidly connected to an atmospheric vent, as described in any one of claims 3 to 5.

7. The door device for a machine tool according to any one of claims 1 to 6, wherein the control device controls the regulator such that the magnitude of the assist force applied to the door changes according to the magnitude of the operating force acting on the handle.

8. A door device for a machine tool according to any one of claims 1 to 7, comprising a support for supporting the strain gauge, the support having a first portion fixed to the door, a second portion to which the handle is fixed, and a third portion on which the strain gauge is arranged, wherein the third portion is arranged between the first portion and the second portion.

9. The door device for a machine tool according to claim 8, wherein the third portion includes a thinned region and a non-thinned region that is thicker than the thinned region, and the strain gauge is disposed in the thinned region.

10. The door device for a machine tool according to claim 8 or 9, wherein the door comprises a first frame, the handle is disposed on the surface of the first frame, and the support is disposed on the back surface of the first frame.

11. The door device for a machine tool according to any one of claims 8 to 10, wherein the strain gauge is positioned on the support at an angle with respect to the longitudinal direction of the support.

12. The door device for a machine tool according to any one of claims 1 to 7, wherein the strain gauges include a first strain gauge, a second strain gauge, a third strain gauge, and a fourth strain gauge arranged in a bridge circuit, wherein when the handle is operated in the first direction, the first strain gauge and the second strain gauge extend, and when the handle is operated in the first direction, the third strain gauge and the fourth strain gauge retract.

13. A door device for a machine tool according to claim 12, comprising a support for supporting the strain gauges, wherein the first strain gauge and the second strain gauge are arranged on a first side surface of the support, and the third strain gauge and the fourth strain gauge are arranged on a second side surface of the support.

14. A machine tool comprising: a work support device for supporting a workpiece; a machining head capable of holding a tool for machining the workpiece; a moving device for moving the machining head relative to the work support device; a numerical control device for controlling the moving device; a wall having an opening; and a door device, wherein the door device comprises: a door that can slide in a first direction so as to open at least a portion of the opening, and a door that can slide in a second direction opposite to the first direction so as to close at least the portion of the opening; a handle disposed on the door; a strain gauge for detecting the operation of the handle; an air cylinder for providing assisting force to the door; an air supply passage connecting the air cylinder and an air supply source; a regulator for adjusting the pressure of the air flowing through the air supply passage; and a control device for controlling the regulator based on a signal from the strain gauge.

15. The machine tool according to claim 14, wherein the control device includes a memory for storing a first group of parameters that define a change in the first target pressure of the air supply passage in response to a change in a first operating force acting on the handle in the first direction, the numerical control device includes a storage device for storing a parameter change program, and a display, and the numerical control device displays a first image on the display that accepts user input for changing the first group of parameters by executing the parameter change program stored in the storage device.

Images