Machine tool

Abstract

A machine tool is provided in which, in a home position resetting operation, a work table for machining does not interfere with a main shaft and a cover in a state in which a tool holder is retracted relative to the main shaft in a main shaft direction. The machine tool (100) includes an X-direction slide mechanism (150) having an X-direction guide rail (151) fixed to a machine body (110) and extending in an X-direction intersecting a Z-direction in which a main shaft (140) extends, and an X-table (152) freely slidable along the X-direction guide rail (151); a Y-direction slide mechanism (170) having a Y-direction guide rail (171) provided on the X-table (152) and extending in a Y-direction intersecting the Z-direction and the X-direction, and a Y-table (172) freely slidable along the Y-direction guide rail (171); and a control device (190) that performs drive control of the X-direction slide mechanism (150) and the Y-direction slide mechanism (170), and a Y-table positioning control section (194a) performs positioning of the Y-table (172) relative to the Y-direction guide rail (171) in a state in which the X-table (152) is positioned in a non-interference region.

Description

Technical Field

[0001] This invention relates to machine tools, and more particularly to machine tools in which the tool post can move freely in two axes. Background Technology

[0002] Previously, there was a known machine tool that had a machining slide (machining table) that could move freely in two axes: a Y-axis perpendicular to the long side of the machine bed (Z-axis) and parallel to the machine bed, and an X-axis perpendicular to both the Y-axis and the Z-axis. By moving the machining slide freely in the Y-axis and X-axis directions, various machining operations could be performed on the workpiece (for example, Patent Document 1).

[0003] Furthermore, the machining sliding parts of this machine tool are equipped with a rotary table (tool holder) for mounting tools such as lathe tools.

[0004] Patent Document 1: Japanese Patent Application Publication No. 4-223802 (for example, see...) Figure 2 )

[0005] In the aforementioned machine tools, in order to perform high-precision workpiece machining, it is necessary to achieve high-precision position control and positioning of the sliding parts used for machining.

[0006] Therefore, the action of periodically moving the machining sliding parts towards the reference point (origin) of the machine tool is called origin reset.

[0007] The origin reset needs to be performed on each control axis. Therefore, when the machining slider can move freely in the X-axis and Y-axis directions, the origin reset about the X-axis and the origin reset about the Y-axis are performed respectively. However, during the origin reset operation, the machine tool cannot accurately grasp the position of the machining slider.

[0008] Therefore, even during origin reset, when the rotary table retracts relative to the spindle along the Z-axis, the machining sliding component may still interfere with the spindle that holds the workpiece and the cover that covers the functional components of the machine tool. Summary of the Invention

[0009] Therefore, the present invention was made to solve the problems of the prior art mentioned above. That is, the object of the present invention is to provide a machine tool in which the machining table does not interfere with the spindle or the cover even during the origin reset operation, when the tool post is retracted relative to the spindle in the spindle direction.

[0010] The invention of the first technical solution provides a machine tool comprising: a spindle mounted on a bed to hold a workpiece; a first sliding mechanism having a first guide rail fixed to the bed and extending along a first direction and a first worktable slidable along the first guide rail, the first direction being a direction intersecting the spindle direction; a second sliding mechanism having a second guide rail disposed on the first worktable of the first sliding mechanism and extending along a second direction and a second worktable slidable along the second guide rail, the second direction being a direction intersecting the spindle direction and the first direction; a tool post mounted on the second worktable of the second sliding mechanism to hold a tool for machining the workpiece; a cover covering the spindle, the first sliding mechanism, the second sliding mechanism, and the tool post; and a control device for driving and controlling the first sliding mechanism and the second sliding mechanism, wherein the tool post is freely movable relative to the spindle and the cover, and the first sliding mechanism... The actuator has a first worktable position detection unit that detects the position of the first worktable relative to the first guide rail. The control device has a second worktable positioning control unit that determines the position of the second worktable relative to the second guide rail at a predetermined position. The first worktable position detection unit detects whether the first worktable is located in an interference-free area or an interference area. The interference-free area refers to the area where the second worktable does not interfere with the spindle or the cover when sliding on the second guide rail. The interference area refers to the area where the second worktable would interfere with the spindle or the cover when sliding on the second guide rail. The second worktable positioning control unit positions the second worktable relative to the second guide rail when the first worktable is located in the interference-free area, thereby solving the aforementioned problem.

[0011] In the second technical solution, based on the machine tool structure described in the first technical solution, the control device has a first worktable positioning control unit, which determines the position of the first worktable relative to the first guide rail at a predetermined position. The first worktable position detection unit is also used for positioning the first worktable relative to the first guide rail of the first sliding mechanism, thereby solving the above-mentioned problem.

[0012] In the third technical solution, based on the machine tool structure described in the first or second technical solution, the first worktable position detection unit has a proximity sensor. The proximity sensor sets the boundary between the non-interference area and the interference area in the first guide rail as the detection position to detect the first worktable, thereby further solving the above-mentioned problem.

[0013] In the fourth technical solution, based on the machine tool structure described in the third technical solution, the aforementioned interference area is formed by the spindle interference area where the second worktable interferes with the spindle and the cover interference area where the second worktable interferes with the cover. The aforementioned non-interference area is formed between the spindle interference area and the cover interference area. The proximity sensor is configured to set the two ends of the non-interference area of ​​the first guide rail as detection positions. The proximity sensor of the first worktable position detection unit is a normally open proximity sensor, thereby solving the aforementioned problem.

[0014] In the fifth invention, based on the structure of the machine tool described in any one of the first to fourth inventions, the first guide rail is inclined relative to the horizontal plane, thereby further solving the aforementioned problem.

[0015] The machine tool of the present invention includes a first sliding mechanism, a second sliding mechanism, and a control device for driving and controlling the first sliding mechanism and the second sliding mechanism. This not only enables the tool holder to be driven in two directions to perform workpiece machining with higher precision, but also achieves the following unique effects of the present invention.

[0016] That is, in the machine tool according to the invention of the first technical solution, the second worktable positioning control unit positions the second worktable relative to the second guide rail while the first worktable is in an interference-free area. Thus, when positioning the second worktable relative to the second guide rail, even if the second worktable slides on the second guide rail, the second worktable does not interfere with the spindle or the cover. Therefore, even when performing positioning such as the origin reset operation, it is possible to reliably prevent the second worktable, which is used as a machining worktable, from interfering with the spindle or the cover when the tool holder is retracted relative to the spindle in the spindle direction.

[0017] In addition to the effects of the machine tool of the first technical solution, the machine tool of the second technical solution also has the function of positioning the first worktable relative to the first guide rail of the first sliding mechanism. Thus, when performing the origin reset action on the first worktable, it is determined whether the first worktable is located in the non-interference area or the interference area. Therefore, when performing the origin reset action on the first worktable, even if the first worktable is located in the interference area, the second worktable is moved to a position where the second worktable does not interfere with the spindle or the cover, and the origin reset action on the first worktable continues. In the origin reset action on the first worktable, interference between the second worktable and the spindle or the cover can be prevented.

[0018] In addition to the effects of the machine tool invented according to the third technical solution, the first worktable position detection unit of the machine tool according to the first or second technical solution has a proximity sensor. The proximity sensor sets the boundary between the non-interference area and the interference area in the first guide rail as the detection position to detect the first worktable. Thus, by detecting the first worktable by the proximity sensor, the position of the first worktable relative to the first guide rail is detected. Therefore, the machine tool can determine whether the first worktable is located in the non-interference area or the interference area with a simple structure.

[0019] In addition to the effects of the machine tool invented according to the fourth technical solution, the proximity sensor of the first worktable position detection unit is a normally open proximity sensor. Therefore, when the first worktable is located in the spindle interference area or the cover interference area, or when the proximity sensor malfunctions, no signal is output from the proximity sensor. In the case of a proximity sensor malfunction, the machine tool determines that the first worktable is located in the interference area, thus preventing the first worktable from being prohibited from moving and thus enabling positioning when the proximity sensor malfunctions.

[0020] The machine tool according to the fifth technical solution, in addition to the effects of the machine tool of any one of the first to fourth technical solutions, has a first guide rail inclined relative to the horizontal plane, thereby reducing the front-to-back width of the bed and thus making the front-to-back width of the machine tool smaller. As a result, the distance between the spindle, tool post and cover becomes closer, and the user of the machine tool can easily access the spindle and tool post. Attached Figure Description

[0021] Figure 1 This is a front view of a machine tool as an embodiment of the present invention.

[0022] Figure 2 It is Figure 1 The front view shows the machine tool with the cover partially removed.

[0023] Figure 3 yes Figure 1 The system structure diagram of the machine tool is shown.

[0024] Figure 4 It is along Figure 2 A side sectional view of the main part of the machine tool as observed along line IV-IV.

[0025] Figure 5 It is along Figure 2 A side sectional view of the main part of the machine tool as observed by the VV line.

[0026] Figure 6 It is along Figure 5 A sectional view of the main parts of the machine tool as observed along line VI-VI.

[0027] Figure 7A This is a side sectional view showing the main part of the interference between the Y-table and the spindle.

[0028] Figure 7B This is a side sectional view showing the main part of the interference between the Y-stage and the cover.

[0029] Figure 8A It means and Figure 7A A diagram showing the location of the corresponding X-stage.

[0030] Figure 8B It means and Figure 7B A diagram showing the location of the corresponding X-stage.

[0031] Figure 8C It means and Figure 4 A diagram showing the location of the corresponding X-stage.

[0032] Figure 9 It means Figure 1 The flowchart shows the process of resetting the origin in the machine tool. Detailed Implementation

[0033] This invention provides a machine tool comprising: a spindle mounted on a bed to hold a workpiece; a first sliding mechanism having a first guide rail fixed to the bed and extending along a first direction, and a first worktable slidable along the first guide rail, the first direction being a direction intersecting the spindle direction; a second sliding mechanism having a second guide rail disposed on the first worktable of the first sliding mechanism and extending along a second direction, and a second worktable slidable along the second guide rail, the second direction being a direction intersecting both the spindle direction and the first direction; a tool post mounted on the second worktable of the second sliding mechanism to hold a tool for machining the workpiece; a cover covering the spindle, the first sliding mechanism, the second sliding mechanism, and the tool post; and a control device for driving and controlling the first sliding mechanism and the second sliding mechanism, wherein the tool post is freely accessible along the spindle and the cover, and the first sliding mechanism having a first worktable position detection unit. The control device includes a second worktable positioning control unit to detect the position of the first worktable relative to the first guide rail. This second worktable positioning control unit determines the position of the second worktable relative to the second guide rail at a predetermined position. The first worktable position detection unit detects which area the first worktable is located in—the non-interference area or the interference area. The non-interference area refers to the area where the second worktable does not interfere with the spindle or the cover even when it slides on the second guide rail. The interference area refers to the area where the second worktable will interfere with the spindle or the cover when it slides on the second guide rail. The second worktable positioning control unit positions the second worktable relative to the second guide rail while the first worktable is in the non-interference area. As long as the second worktable, which is used as a machining worktable, does not interfere with the spindle or the cover when the tool holder retracts relative to the spindle in the spindle direction during the origin reset operation, this specific implementation method can be arbitrary.

[0034] For example, the cover in the machine tool of the present invention can be any type of cover as long as it covers the spindle, the first sliding mechanism, the second sliding mechanism, and the tool post. It can be an exterior cover that forms the appearance of the machine tool, or it can be a component disposed inside the exterior cover.

[0035] For example, the tool holder in the machine tool of the present invention can be a rotary table with multiple tools or a tool holder with a single tool.

[0036] For example, the first direction in the machine tool of the present invention can be any direction as long as it intersects the spindle direction, or it can be a direction that is inclined relative to the horizontal plane, or it can be a direction that intersects the spindle direction on the horizontal plane.

[0037] For example, the second direction in the machine tool of the present invention can be any direction as long as it intersects with the spindle direction and the first direction. It can also be a direction inclined relative to the horizontal plane or a direction perpendicular to the horizontal plane.

[0038] For example, the predetermined position of the second worktable relative to the second guide rail determined by the second worktable positioning control unit in the machine tool of the present invention can be the position of the origin, or it can be other predetermined positions.

[0039] Example 1

[0040] The following is based on Figures 1 to 9 The machine tool 100, which is an embodiment of the present invention, will be described.

[0041] <1. Overview of Machine Tools>

[0042] First, based on Figures 1 to 6 The general outline of machine tool 100 is described.

[0043] Figure 1 This is a front view of the machine tool as a first embodiment of the present invention. Figure 2 It is Figure 1 The front view shown depicts the machine tool with its cover partially removed. Figure 3 yes Figure 1 The system structure diagram of the machine tool shown is as follows. Figure 4 It is along Figure 2 A side sectional view of the main part of the machine tool as observed along line IV-IV. Figure 5 It is along Figure 2 A side sectional view of the main parts of the machine tool as observed by the VV line. Figure 6 It is along Figure 5 A sectional view of the main parts of the machine tool as observed along line VI-VI.

[0044] <1.1. Appearance and Structure>

[0045] Machine tool 100 is an automatic lathe, such as Figure 1 As shown, the machine tool 100 includes a bed 110 placed on the ground F, a rectangular cover 120 forming the appearance, and an operation panel 130 for the user of the machine tool 100 to operate the machine tool 100.

[0046] The bed frame 110 is rectangular when viewed from above.

[0047] Hereinafter, the vertical direction relative to the ground F is defined as the up-down direction of the machine tool 100, the long side direction of the bed 110 when viewed from above is defined as the left-right direction (Z direction) of the machine tool 100, and the short side direction of the bed 110 when viewed from above is defined as the front-back direction of the machine tool 100.

[0048] In addition, such as Figure 4 As shown, the bed 110 has an inclined base surface 111 that slopes downward from the rear to the front when viewed from the side.

[0049] Hereinafter, the tilt direction of the tilted base surface 111, which is tilted relative to the horizontal plane, will be defined as the X direction.

[0050] like Figure 1 As shown, the exterior cover 120 has a sliding door 121 that can be opened and closed freely in the left and right directions near the center in the left and right direction.

[0051] By opening the sliding door 121, the user of the machine tool 100 can access the machining room PR (see reference) where workpieces are machined. Figure 2 )Inside.

[0052] In addition, such as Figure 1 as well as Figure 4 As shown, an operating panel receiving recess 122 is formed on the upper left side of the outer cover 120, facing rearward and recessed downward to receive the operating panel 130.

[0053] And, as Figure 4 As shown, the lower left side of the outer cover 120 bulges forward.

[0054] like Figure 4 As shown, the operation panel 130 stands upright on the operation panel mounting surface 122a, which is the bottom surface of the operation panel receiving recess 122 that forms the outer cover 120, and the display surface 131 and the keys 132 are provided on the front surface of the operation panel.

[0055] <1.2. Internal Structure>

[0056] like Figure 2 as well as Figure 3 As shown, the machine tool 100 also includes: a spindle 140 and an X-direction sliding mechanism (first sliding mechanism) 150, which is mounted on the inclined base surface 111 of the bed 110 to hold the workpiece; a Z-direction sliding mechanism 160, which is fixed to the X-direction sliding mechanism 150; a Y-direction sliding mechanism (second sliding mechanism) 170, which is fixed to the Z-direction sliding mechanism 160; a rotary table (tool post) 180, which is disposed on the Y-direction sliding mechanism 170; and a control device 190, which controls the operation of the machine tool 100.

[0057] Moreover, such as Figure 4 As shown, the main spindle 140, the X-direction sliding mechanism 150, the Y-direction sliding mechanism 170, and the turntable 180 are covered by the outer cover 120.

[0058] <1.2.1. Main Axis>

[0059] The spindle 140 extends along the Z direction (the "spindle direction" in this invention) and is composed of a spindle table 141 fixed to the inclined base surface 111 of the bed 110 along the left-right sliding mechanism 150 in the X direction, and a spindle body 142 placed on the spindle table 141.

[0060] <1.2.2. X-direction sliding mechanism>

[0061] like Figures 4 to 6 As shown, the X-direction sliding mechanism 150 includes: an X-direction guide rail (first guide rail) 151 fixed to the inclined base surface 111 of the bed 110; a metal X-stage (first stage) 152 that slides freely along the X-direction guide rail 151; an X-stage drive shaft 153 that drives the X-stage 152; an X-direction drive motor 154 that rotates the X-stage drive shaft 153 based on control from the control device 190; a spindle-side stop member 155 and a cover-side stop member 156 that form the sliding end of the X-stage 152; and an X-stage position detection unit (first stage position detection unit) 157 that detects the position of the X-stage 152 relative to the X-direction guide rail 151.

[0062] X-axis guide rail 151 Figure 4 It extends along the X direction (the "first direction" in this invention) as shown.

[0063] That is, in this embodiment, the X-direction guide rail 151 is as follows: Figure 2 As shown, it is orthogonal (intersecting) to the extension direction of the main axis 140, i.e., the Z direction, and as shown... Figure 4 It is tilted relative to the horizontal plane as shown.

[0064] The X-stage 152 is screwed onto the X-stage drive shaft 153, and moves forward and backward by rotating the X-stage drive shaft 153.

[0065] In addition, the sliding range of the X-stage 152 is physically limited by the spindle-side stop member 155 provided on the spindle 140 side of the X-direction sliding mechanism 150 and the cover-side stop member 156 provided on the outer cover 120 side of the X-direction sliding mechanism 150.

[0066] Furthermore, a recessed region 152a1 extending in the Z direction for mounting the Z-direction sliding mechanism 160 is formed on the X-stage base surface 152a of the X-stage 152 opposite to the outer cover 120.

[0067] like Figure 5 as well as Figure 6 As shown, the X-table position detection unit 157 includes: a normally open proximity sensor 157a, which uses the specified position of the X-direction guide rail 151 as the detection position to detect the X-table 152; and a bracket 157b, which is used to mount the proximity sensor 157a to the bed 110.

[0068] The proximity sensor 157a is a proximity sensor (e.g., eddy current type) that can detect the mark even in the presence of lubricating oil, etc., and is connected to the control device 190.

[0069] In addition, such as Figure 6 As shown, the proximity sensor 157a is mounted on the inclined base surface 111 of the bed 110 via a bracket 157b.

[0070] Moreover, such as Figure 5 As shown, the proximity sensor 157a consists of two parts: a spindle-side proximity sensor 157a1 disposed on the spindle 140 side and a cover-side proximity sensor 157a2 disposed on the cover 120 side.

[0071] <1.2.3. Z-direction sliding mechanism>

[0072] like Figure 4 as well as Figure 5 As shown, the Z-direction sliding mechanism 160 includes: a Z-stage 161 that slides freely relative to the X-stage 152; a Z-stage drive shaft 162 that drives the Z-stage 161; and a Z-direction drive motor (not shown) that rotates the Z-stage drive shaft 162 based on control from the control device 190.

[0073] The Z-direction sliding mechanism 160 configured in this way, based on the control from the control device 190, allows the Z-stage 161 to slide freely relative to the X-stage 152 in the Z direction.

[0074] <1.2.4. Y-direction sliding mechanism>

[0075] like Figure 4 as well as Figure 5 As shown, the Y-direction sliding mechanism 170 includes: a Y-direction guide rail (second guide rail) 171, fixed to the Z-direction sliding mechanism 160's Z-stage 161; a Y-stage (second stage) 172, which slides freely along the Y-direction guide rail 171; a Y-stage drive shaft 173, which drives the Y-stage 172; and a Y-direction drive motor (not shown), which rotates the Y-stage drive shaft 173 based on control from the control device 190.

[0076] like Figure 4 As shown, the Y-direction guide rail 171 extends along the Y-direction (the "second direction" in this invention).

[0077] That is, in this embodiment, the Y-direction guide rail 171 is as follows: Figure 4 It is arranged on the X worktable 152 of the X-direction sliding mechanism 150 as shown and extends along the Y direction, which intersects the Z direction and the X direction.

[0078] The Y-table 172 is screwed into the Y-table drive shaft 173, and moves forward and backward by rotating the Y-table drive shaft 173.

[0079] In addition, the sliding range of the Y-stage 172 is physically limited by the cover-side abutment portion 171a provided on the cover side of the Y-direction guide rail 171 and the spindle-side abutment portion 171b provided on the spindle side of the Y-direction guide rail 171.

[0080] <1.2.5. Turntable>

[0081] like Figure 3 As shown, the turntable 180 holds the tool (not shown) for machining the workpiece, which is mounted on the Y worktable 172 of the Y-direction sliding mechanism 170.

[0082] The rotary table 180 is placed on the Y stage 172, and the Y stage 172 is placed on the X stage 152 via the Z stage 161, so the rotary table 180 is freely movable relative to the spindle 140 and the outer cover 120.

[0083] <1.2.6. Control Device>

[0084] Control device 190 is a control device that drives and controls at least the spindle 140, the X-direction sliding mechanism 150, and the Y-direction sliding mechanism 170, such as... Figure 3 As shown, it includes: a spindle control unit 191 for driving control of the spindle 140; an X-direction sliding mechanism control unit 192 for driving control of the X-direction sliding mechanism 150; a Z-direction sliding mechanism control unit 193 for driving control of the Z-direction sliding mechanism 160; and a Y-direction sliding mechanism control unit 194 for driving control of the Y-direction sliding mechanism 170.

[0085] The X-direction sliding mechanism control unit 192 includes an X-direction positioning control unit (first worktable positioning control unit) 192a that drives and controls the X-direction drive motor 154 to determine the position of the X-direction worktable 152 relative to the X-direction guide rail 151 at a predetermined position.

[0086] The Y-direction sliding mechanism control unit 194 includes a Y-direction positioning control unit (second worktable positioning control unit) 194a that controls the Y-direction drive motor to determine the position of the Y-direction worktable 172 relative to the Y-direction guide rail 171 at a predetermined position.

[0087] <2. Y Workbench Actions>

[0088] Next, regarding the movement of the Y-table 172 in the machine tool 100 configured in this way, based on Figures 7A to 8C To explain in further detail.

[0089] Figure 7A This is a side sectional view showing the main part of the interference between the Y-table and the spindle. Figure 7BThis is a side sectional view showing the main part of the interference between the Y-stage and the cover. Figure 8A It means and Figure 7A A diagram showing the location of the corresponding X-stage. Figure 8B It means and Figure 7B A diagram showing the location of the corresponding X-stage. Figure 8C It means and Figure 4 A diagram showing the location of the corresponding X-stage.

[0090] Even if the Y-table 172 is moved along the Z-direction and the rotary table 180 is moved away from the spindle 140 along the Z-direction, the Y-table 172 may sometimes interfere with the outer cover 120 and the spindle 140 depending on the position of the X-table 152.

[0091] Specifically, if is Figure 7A as well as Figure 8A The position of the X-axis of the X-axis worktable 152 shown in these figures means that, depending on the position of the Y-axis of the Y-axis worktable 172, the Y-axis worktable 172 will interfere with the spindle stage 141 and the spindle body 142 of the spindle 140.

[0092] Additionally, if it is Figure 7B as well as Figure 8B The position of the X-axis of the X-stage 152 shown in these figures will cause the Y-axis of the Y-stage 172 to interfere with the outer cover 120, depending on the position of the Y-axis of the Y-stage 172.

[0093] On the other hand, if it is Figure 4 as well as Figure 8C The position of the X-stage 152 in the X direction means that no matter what the position of the Y-stage 172 is in the Y direction, the Y-stage 172 will not interfere with the outer cover 120 or the spindle 140.

[0094] Therefore, on the X-direction guide rail 151 of the machine tool 100, as Figures 8A to 8C As shown, there exists a region (non-interference region NIA) of the X-stage 152 relative to the X-direction guide rail 151, even if... Figure 4 as well as Figure 8C The Y-stage 172 shown slides on the Y-direction guide rail 171. The Y-stage 172 does not interfere with the spindle 140 or the outer cover 120. Furthermore, there is an area (interference area IA) of the X-stage 152 relative to the X-direction guide rail 151. Figure 7A and Figure 8A as well as Figure 7B and Figure 8B When the Y-stage 172 shown slides on the Y-direction guide rail 171, the Y-stage 172 will interfere with the spindle 140 or the outer cover 120.

[0095] That is, the interference area IA is formed by the spindle interference area IAs that interferes with the spindle 140 and the cover interference area IAc that interferes with the cover 120. The non-interference area NIA is formed between the spindle interference area IAs and the cover interference area IAc.

[0096] Moreover, such as Figures 8A to 8C As shown, the proximity sensor 157a is a proximity sensor that sets the boundaries of the non-interference region NIA and the interference region IA of the X-direction guide rail 151 (i.e., the boundary between the main shaft interference region IAS and the non-interference region NIA, and the boundary between the cover interference region IAC and the non-interference region NIA) as the detection positions.

[0097] That is, the spindle-side proximity sensor 157a1 is set to set the boundary between the spindle interference region IAS and the non-interference region NIA of the X-direction guide rail 151 as the detection position, and the cover-side proximity sensor 157a2 sets the boundary between the cover interference region IAc and the non-interference region NIA of the X-direction guide rail 151 as the detection position.

[0098] Furthermore, in other words, the proximity sensor 157a is normally open. Therefore, when the X stage 152 is in the non-interference area NIA, the spindle-side proximity sensor 157a1 and the cover-side proximity sensor 157a2 are turned on. When the X stage 152 is in the interference area IA, one of the spindle-side proximity sensor 157a1 or the cover-side proximity sensor 157a2 is turned on, and the other is turned off.

[0099] <3. Origin Reset Action>

[0100] Next, based on representation Figure 1 The flowchart shown is the process of the origin reset action in the machine tool. Figure 9 An example of the origin reset operation in the machine tool 100 after the Y worktable 172 is moved along the Z direction and the rotary table 180 is retracted relative to the spindle 140 along the Z direction will be described.

[0101] <3.1. Y-table origin reset action>

[0102] First, the control device 190 uses the X-stage position detection unit 157 to detect which region of the interference-free region NIA or the interference region IA the X-stage 152 is located in.

[0103] That is, the control device 190 determines whether all proximity sensors 157a are disconnected (step S10).

[0104] If both proximity sensors 157a are disconnected, it is assumed that both proximity sensors 157a are faulty, and no origin reset action is performed.

[0105] Conversely, if none of the proximity sensors 157a are disconnected, determine whether all of the proximity sensors 157a are connected (step S11).

[0106] When the proximity sensor 157a is not turned on, the X stage 152 is located in the cover interference area IAc or the spindle interference area IAS, so the X stage 152 is moved to the interference-free area NIA (step S12).

[0107] With all proximity sensors 157a activated, the X stage 152 is located in the interference-free region NIA. Therefore, the Y stage positioning control unit 194a of the control device 190 performs the origin reset operation of the Y stage 172 (step S13).

[0108] Specifically, the Y-stage positioning control unit 194a drives the Y-direction drive motor to move the Y-stage 172 until it reaches the contact portion 172a on the outer cover side of the Y-stage 172 (see reference). Figure 4 ) and the cover-side contact portion 171a provided on the Y-direction guide rail 171 (refer to Figure 4 Until it reaches the destination.

[0109] The position where the contact portion 172a of the Y worktable 172 abuts against the cover-side contact portion 171a of the Y-direction guide rail 171 deviates from the predetermined amount becomes the origin point set on the control device 190 when the Y worktable 172 moves in the Y direction.

[0110] <3.2.X Worktable Origin Reset Action>

[0111] Thus, after the origin reset action of Y worktable 172 is completed, control device 190 again uses X worktable position detection unit 157 to detect which area of ​​interference-free area NIA or interference area IA X worktable 152 is located in.

[0112] That is, the control device 190 re-determines whether all proximity sensors 157a are disconnected (step S20).

[0113] If both proximity sensors 157a are disconnected, it is assumed that both proximity sensors 157a are faulty, and no origin reset action is performed.

[0114] Conversely, if none of the proximity sensors 157a are disconnected, determine whether all of the proximity sensors 157a are connected (step S21).

[0115] When the proximity sensors 157a are not activated, the X stage 152 is located in the cover interference area IAc or the spindle interference area IAS, so the X stage 152 is moved to the interference-free area NIA (step S22).

[0116] With all proximity sensors 157a activated, the X stage 152 is located in the interference-free area NIA. Therefore, the Y stage positioning control unit 194a of the control device 190 moves the Y stage 172 to a predetermined safe position (a position where the Y stage 172 does not interfere with the outer cover 120 or the spindle 140, regardless of the position of the X stage 152) (step S23).

[0117] In this state, the X-stage positioning control unit 192a of the control device 190 performs the origin reset operation of the X-stage 152 (step S24).

[0118] Specifically, the X-stage positioning control unit 192a drives the X-direction drive motor 154 to move the X-stage 152 until the contact portion 152b on the outer cover side of the X-stage 152 comes into contact with the cover side stop member 156.

[0119] The position where the contact portion 152b of the X worktable 152 abuts against the side stop member 156 deviates by a predetermined amount becomes the origin point set on the control device 190 when the X worktable 152 moves in the X direction.

[0120] In this way, the X-stage position detection unit 157 is also used for positioning the X-stage 152 relative to the X-direction guide rail 151 of the X-direction sliding mechanism 150.

[0121] <4. The effect of machine tool 100>

[0122] According to the machine tool 100 described above, the Y-table positioning control unit 194a, which is the second table positioning control unit, positions the Y-table 172, which is the second table, relative to the Y-direction guide rail 171, which is the second guide rail, when the X-table 152, which is the first table, is in the interference-free region NIA. Thus, when positioning the Y-table 172 relative to the Y-direction guide rail 171, even if the Y-table 172 slides on the Y-direction guide rail 171, the Y-table 172 will not interfere with the spindle 140 or the outer cover 120, which is the cover. Therefore, even when performing a positioning operation such as origin reset, it is possible to reliably prevent the Y-table 172 from interfering with the spindle 140 and the outer cover 120 when the rotary table 180, which is the tool holder, is retracted relative to the spindle 140 in the Z-direction, which is the spindle direction.

[0123] In addition, the X-stage position detection unit 157, which is the first stage position detection unit, is also used to position the X-stage 152 relative to the X-direction guide rail 151 of the X-direction sliding mechanism 150, which is the first sliding mechanism. Thus, when performing the origin reset operation on the X-stage 152, it is determined whether the X-stage 152 is located in the non-interference area NIA or the interference area IA. Therefore, when performing the origin reset operation on the X-stage 152, even if the X-stage 152 is located in the interference area IA, the Y-stage 172 is moved to a position where the Y-stage 172 does not interfere with the spindle 140 or the outer cover 120, and the origin reset operation on the X-stage 152 continues. During the origin reset operation on the X-stage 152, interference between the Y-stage 172 and the spindle 140 or the outer cover 120 can be prevented.

[0124] In addition, the X-table position detection unit 157 has a proximity sensor 157a, which detects the X-table 152 by setting the boundary between the non-interference area NIA and the interference area IA in the X-direction guide rail 151 as the detection position. Thus, by detecting the X-table 152 by the proximity sensor 157a, the position of the X-table 152 relative to the X-direction guide rail 151 is detected. Therefore, the machine tool 100 can determine whether the X-table 152 is located in the non-interference area NIA or the interference area IA with a simple structure.

[0125] In addition, the proximity sensor 157a of the X-table position detection unit 157 is a normally open proximity sensor. Therefore, when the X-table 152 is located in the spindle interference area IAs or the cover interference area IAc, or when the proximity sensor 157a malfunctions, no signal is output from the proximity sensor 157a. In the case of a malfunction of the proximity sensor 157a, the machine tool 100 determines that the X-table 152 is located in the interference area IA. Therefore, it is possible to prevent the movement of the X-table 152 from being prohibited and to perform positioning when the proximity sensor 157a malfunctions.

[0126] <Variation Example>

[0127] The machine tool described above is an embodiment of the present invention, but the machine tool of the present invention is not limited to the machine tool of the above embodiment.

[0128] For example, in the above embodiments, from the viewpoint of fault detection, the proximity sensor is normally open, but it can also be normally closed, where the signal is disconnected during the detection of the object.

[0129] Explanation of reference numerals in the attached figures

[0130] 100…Machine tool; 110…Bed; 111…Inclined base surface; 120…Exterior cover; 121…Sliding door; 122…Operating panel storage recess; 122a…Operating panel mounting surface; 130…Operating panel; 140…Spindle; 141…Spindle table; 142…Spindle body; 150…X-direction sliding mechanism (first sliding mechanism); 151…X-direction guide rail (first guide rail); 152…X-worktable (first worktable); 1 52a…X-table base surface; 152a1…recessed area; 152b…abutment part; 153…X-table drive shaft; 154…X-direction drive motor; 155…spindle-side stop part; 156…cover-side stop component; 157…X-table position detection unit (first table position detection unit); 157a…proximity sensor; 157a1…spindle-side proximity sensor; 157a2…cover-side proximity sensor; 157b…bracket ; 160…Z-direction sliding mechanism; 161…Z-stage; 162…Z-stage drive shaft; 170…Y-direction sliding mechanism (second sliding mechanism); 171…Y-direction guide rail (second guide rail); 171a…shelter side contact part; 172…Y-stage (second stage); 172a…contact part; 173…Y-stage drive shaft; 180…rotary table (tool holder); 190…control device; 191…spindle control unit; 192…X-direction sliding mechanism control unit; 192a…X-stage positioning control unit (first stage positioning control unit); 193…Z-direction sliding mechanism control unit; 194…Y-direction sliding mechanism control unit; 194a…Y-stage positioning control unit (second stage positioning control unit); F…ground; PR…machining chamber; IA…interference area; IAS…spindle interference area; IAc…shelter interference area; NIA…non-interference area.

Claims

1. A machine tool, characterized in that, The device comprises: a spindle mounted on a machine bed to hold a workpiece; a first sliding mechanism having a first guide rail fixed to the machine bed and extending along a first direction, and a first worktable slidable along the first guide rail, the first direction being a direction intersecting the spindle's spindle direction; a second sliding mechanism having a second guide rail disposed on the first worktable of the first sliding mechanism and extending along a second direction, and a second worktable slidable along the second guide rail, the second direction being a direction intersecting both the spindle direction and the first direction; a tool holder mounted on the second worktable of the second sliding mechanism to hold a tool for machining the workpiece; a cover covering the spindle, the first sliding mechanism, the second sliding mechanism, and the tool holder; and a control device for driving and controlling the first sliding mechanism and the second sliding mechanism, the tool holder being freely movable relative to the spindle and the cover. The first sliding mechanism has a first worktable position detection unit, which detects the position of the first worktable relative to the first guide rail. The control device includes a second worktable positioning control unit, which determines the position of the second worktable relative to the second guide rail at a predetermined position. The first worktable position detection unit detects which area the first worktable is located in—either the interference-free area or the interference area. The interference-free area refers to the area where the second worktable does not interfere with the spindle or the cover even when sliding on the second guide rail. The interference area refers to the area where the second worktable would interfere with the spindle or the cover when sliding on the second guide rail. The second worktable positioning control unit positions the second worktable relative to the second guide rail while the first worktable is in the interference-free area.

2. The machine tool according to claim 1, characterized in that, The control device includes a first worktable positioning control unit, which determines the position of the first worktable relative to the first guide rail at a predetermined position. The first worktable position detection unit is also used for positioning the first worktable relative to the first guide rail of the first sliding mechanism.

3. The machine tool according to claim 1 or 2, characterized in that, The first worktable position detection unit has a proximity sensor, which uses the boundary between the interference-free area and the interference area in the first guide rail as the detection position to detect the first worktable.

4. The machine tool according to claim 3, characterized in that, The interference area is formed by the spindle interference area where the second worktable interferes with the spindle and the cover interference area where the second worktable interferes with the cover. The interference-free region is formed between the spindle interference region and the cover interference region. The proximity sensor is configured to set the two ends of the interference-free area of ​​the first guide rail as detection positions. The proximity sensor of the first worktable position detection unit is a normally open proximity sensor.

5. The machine tool according to any one of claims 1 to 4, characterized in that, The first guide rail is inclined relative to the horizontal plane.

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