Machine tool

Abstract

[Problem] To suppress the occurrence of adverse effects due to vibration during cutting. [Solution] The present invention comprises: a cutting mechanism 220 having a cutting body part 221 provided with a cutting tool 231; a workpiece pressing mechanism 250 having a workpiece pressing body part 310 provided with a contact part 322; and a first direction moving body (second slider 210) capable of moving in a first direction. The cutting mechanism 220 is capable of moving in the vertical direction relative to the second slider 210, and moves in the vertical direction by means of a cutting first motor 223. The workpiece pressing mechanism 250 is attached to the second slider 210 at a position different from the attachment position of the cutting mechanism 220 and moves in the vertical direction by means of a workpiece pressing motor 300, and a workpiece W is cut by means of the cutting mechanism 220 while the upper surface of the workpiece W is pressed with the contact part 322 by means of the workpiece pressing mechanism 250.

Description

Machine tool

[0001] The present invention relates to a machine tool.

[0002] Patent Document 1 discloses a machine tool that presses a workpiece from above when performing cutting. This machine tool has an air cylinder, and the workpiece is pressed from above by driving this air cylinder.

[0003] Japanese Utility Model Laid-Open No. 01-00127

[0004] In the technology described in Patent Document 1, the movement of the cutting mechanism and the workpiece pressing mechanism with respect to the workpiece is not considered. Further, since the cutting mechanism for performing cutting on the workpiece and the workpiece pressing mechanism for pressing the workpiece are arranged close to each other, depending on their connection relationship, the vibration generated when the cutting mechanism performs cutting on the workpiece may be directly transmitted to the workpiece pressing mechanism, which may cause problems.

[0005] An object of the present invention is to suppress the occurrence of adverse effects due to vibration during cutting while realizing the movement of the cutting mechanism and the workpiece pressing mechanism with respect to the workpiece in a machine tool provided with a workpiece pressing mechanism that presses the workpiece from above when performing cutting.

[0006] A machine tool according to an aspect of the present invention comprises: a cutting mechanism having a cutting body part equipped with a cutting spindle and a cutting tool attached to the cutting spindle, and a first cutting motor which is a drive source for moving the cutting body part in the vertical direction; a workpiece holding mechanism having a workpiece holding body part equipped with a contact portion that contacts the upper surface of a workpiece, and a workpiece holding motor which is a drive source for moving the workpiece holding body part in the vertical direction; and a first direction moving body that is movable in a first direction which is perpendicular to the vertical direction, wherein the cutting mechanism is mounted to the first direction moving body so as to be movable in the vertical direction relative to it, and is moved in the vertical direction relative to the first direction moving body by the drive of the first cutting motor, and the workpiece holding mechanism is mounted to the first direction moving body at a position different from the mounting position of the cutting mechanism on the first direction moving body so as to be movable in the vertical direction relative to it, and is moved in the vertical direction relative to the first direction moving body by the drive of the workpiece holding motor, and the workpiece is cut by the cutting mechanism while the upper surface of the workpiece is held in place by the contact portion of the workpiece holding mechanism.

[0007] In the machine tool according to an aspect of the present invention, the cutting mechanism and the workpiece holding mechanism are each movable relative to the first directional moving body in the vertical direction. Therefore, by driving the first cutting motor, the cutting mechanism can be moved relative to the workpiece, and by driving the workpiece holding motor, the workpiece holding mechanism can be moved relative to the workpiece. Furthermore, since the workpiece holding mechanism is mounted at a position different from the mounting position of the cutting mechanism on the first directional moving body, vibrations during cutting by the cutting mechanism are transmitted to the workpiece holding mechanism via the first directional moving body, and adverse effects on the workpiece holding mechanism during cutting can be suppressed. In other words, since the cutting mechanism and the workpiece holding mechanism are not directly connected to each other but are connected via the first directional moving body, vibrations of the cutting mechanism when performing oscillating cutting or step cutting are not directly transmitted to the workpiece holding mechanism. As a result, vibrations of the workpiece holding mechanism are suppressed during cutting, and the workpiece holding mechanism can properly hold the workpiece. In addition, a workpiece holding motor is used as the drive source for moving the workpiece holding body vertically, rather than an air cylinder, and the holding force is controlled by controlling the rotation of the workpiece holding motor. With this configuration, the holding force on the workpiece can be easily controlled. As a result, the workpiece can be held with the appropriate clamping force, thus preventing excessive clamping that could cause the workpiece to bend.

[0008] Furthermore, according to the above embodiment of the machine tool, a gantry that can move in a second direction perpendicular to both the first direction and the vertical direction may be provided, and a first-direction moving body may be provided on the gantry. With such a configuration, by moving the gantry in the second direction, the cutting mechanism and the workpiece holding mechanism can be moved together in the second direction. In addition, the vertical reaction force when the workpiece is processed by the cutting mechanism and the reaction force when the workpiece is held by the workpiece holding mechanism are received by the gantry via the first-direction moving body, so the vertical movement of the cutting mechanism and the workpiece holding mechanism can be suppressed.

[0009] Furthermore, according to the machine tool of the above embodiment, the cutting mechanism includes a lifting section integrally provided with the cutting spindle, the lifting section is fitted with a guide section provided vertically on the side of the first directional moving body, and is provided to be able to move relative to the first directional moving body in the vertical direction guided by the guide section, and includes a ball screw for converting the rotational power of the first cutting motor into linear driving force and transmitting it to the lifting section, the nut of the ball screw is provided integrally with the lifting section, and the screw shaft of the ball screw may be connected to the output shaft of the first cutting motor. With this configuration, the cutting spindle can be moved appropriately in the vertical direction.

[0010] Furthermore, according to the machine tool of the above embodiment, the workpiece holding mechanism includes a power transmission unit integrally provided with the contact portion, a part of the power transmission unit has spline teeth formed thereon, and the first directional moving body has spline grooves extending vertically that mesh with the spline teeth of the power transmission unit, and these are spline-fitted with each other so that the power transmission unit is provided so that it can move vertically relative to the first directional moving body, and a ball screw is provided for converting the rotational power of the workpiece holding motor into linear driving force and transmitting it to the power transmission unit, the screw shaft of the ball screw is formed in a part of the power transmission unit, and the nut of the ball screw may be connected to the output shaft of the workpiece holding motor via the power transmission mechanism. With such a configuration, the contact portion can be appropriately moved vertically.

[0011] Furthermore, according to the above embodiment of the machine tool, a workpiece holding control unit is provided to control the workpiece holding motor. The workpiece holding control unit may obtain a target value for the holding force applied to the upper surface of the workpiece by the contact portion from an external device and rotate the workpiece holding motor until the holding force reaches the target value. With this configuration, the holding force can be easily changed by adjusting the target value.

[0012] Furthermore, according to the machine tool of the above embodiment, the workpiece holding control unit may stop the rotational operation of the workpiece holding motor and lock its position so that the position of the contact portion does not fluctuate when the holding force reaches a target value. With such a configuration, the rigidity of the workpiece support that supports the workpiece from below can be improved compared to the case in which the workpiece is always held in place while fluctuations in the position of the holding member are permitted.

[0013] Furthermore, the machine tool according to the above embodiment may be further equipped with a locking mechanism that locks the position of the contact portion so that its position does not change when the clamping force reaches a target value. With such a configuration, the rigidity of the work support that supports the workpiece from below can be improved compared to the case in which the workpiece is always held down while fluctuations in the position of the contact portion are permitted.

[0014] Furthermore, according to the machine tool of the above embodiment, the workpiece holding motor is provided with a rotation detection unit that detects the rotation of the workpiece holding motor, and the workpiece holding control unit may obtain the position in the height direction of the contact portion from the detection signal from the rotation detection unit. In addition, a cutting motor control unit that controls the first cutting motor is provided, and the workpiece holding control unit may set the position in the height direction of the contact portion as the position of the top surface of the workpiece. With such a configuration, position information regarding the height of the top surface of the workpiece necessary for cutting can be accurately grasped. The cutting motor control unit also executes a predetermined process based on the set top surface position, and the predetermined process may include either or both of the following: control of the feed amount of the cutting tool and detection of the thickness of the workpiece. With such a configuration, the feed amount of the cutting tool and the detection of the thickness of the workpiece can be easily obtained. Furthermore, the workpiece holding motor may be a servo motor. By using a servo motor, the position in the height direction of the contact portion can be easily adjusted.

[0015] This figure shows an example of a machine tool according to this embodiment. This is a schematic diagram of the main configuration of the cutting unit according to this embodiment. This is a detailed configuration diagram of the cutting unit according to this embodiment. This is a schematic diagram modeling the mechanism of the cutting unit according to this embodiment. This figure schematically shows the state when cutting is performed without the workpiece holding mechanism according to this embodiment. This figure explains the operation flow of the cutting unit according to this embodiment. This is a schematic diagram of the state with the workpiece held according to this embodiment. This figure shows the workpiece behavior under condition (1) according to this embodiment. This figure shows the workpiece behavior under condition (2) according to this embodiment. This figure shows the workpiece behavior under condition (3) according to this embodiment. This figure shows the workpiece behavior under condition (4) according to this embodiment. This figure shows the trajectories of the first end and the second end of the tip of the drill in oscillating cutting according to this embodiment.

[0016] The present invention will be described below through embodiments, but the following embodiments are not limited to the invention as defined in the claims. Furthermore, not all combinations of features described in the embodiments are necessarily essential to the solution of the invention. In addition, in the drawings, the same or similar parts are denoted by the same reference numerals, and redundant explanations may be omitted. Also, the shape and size of elements in the drawings may be exaggerated for clearer explanation, and may differ in shape and dimensions from the actual product.

[0017] The directions in the diagram below will be explained using the XYZ coordinate system. In this XYZ coordinate system, the vertical direction is the Z direction, and the horizontal directions are the X and Y directions. In addition, the X, Y, and Z directions will be referred to as the + side with the arrows pointing to them, and the opposite side with the - side. The Y direction is an example of the first direction. The X direction is an example of the second direction. The Z direction is an example of the third direction. The first direction is, for example, one direction on the horizontal plane. The second direction is a direction in the horizontal plane that is perpendicular to the first direction. In other words, the second direction is a direction perpendicular to the up and down direction (Z direction) and the first direction. The third direction is a direction perpendicular to the first and second directions. For example, if the third direction is the direction perpendicular to the horizontal plane, the third direction can also be referred to as the up and down direction.

[0018] The cutting unit according to this embodiment performs cutting on a plate-shaped workpiece W. Figure 1 is a diagram showing an example of a machine tool 1 to which the cutting unit according to this embodiment is applied. The machine tool 1 shown in Figure 1 is capable of performing both laser processing and cutting on the workpiece W in the processing area R. However, it is not limited to this, and the machine tool 1 may be a machine tool that performs only cutting on a plate-shaped workpiece W.

[0019] The machine tool 1 shown in Figure 1 performs laser processing and cutting on a workpiece W located in the processing area R. The processing area for laser processing and the processing area for cutting may be the same area. In this case, for example, when the machine tool 1 performs cutting on a workpiece W after laser processing on the same workpiece W, the cutting can be performed without moving the workpiece W to a processing area different from the laser processing area.

[0020] As shown in Figure 1, the machine tool 1 comprises a pallet 110, a laser processing device 120, a cutting device 130, and a control device 140. A plate-shaped workpiece W is an example of a workpiece. The pallet 110 is a member that supports the workpiece W. The pallet 110 comprises a base plate 111 and a plurality of support plates 112. The base plate 111 is a plate-shaped member. The plurality of support plates 112 are provided in an upright position relative to the base plate 111.

[0021] As shown in Figure 1, the support plate 112 is a plate-shaped member having a plurality of protrusions 112P at its upper end. For example, the plurality of protrusions 112P have a sawtooth shape. The pallet 110 is movable in and out of the machine tool 1. In the example shown in Figure 1, the pallet 110 moves in the ±X direction on a pair of rails 101 provided on the machine tool. The pallet 110 is supported by the pair of rails 101. The machine tool 1 performs laser processing or cutting on the workpiece W on the pallet 110 while the pallet 110 is supported by the pair of rails 101. The pair of rails 101 are attached, for example, to a first frame F1 and a second frame F2. The first frame F1 and the second frame F2 are installed, for example, on the floor.

[0022] The laser processing apparatus 120 comprises a laser head 121, a first gantry 122, a first slider 123, and a first lifting unit 124. The laser head 121 irradiates a workpiece W supported on a pallet 110 with laser light to laser process the workpiece W. The laser head 121 is installed in the first gantry 122. The laser head 121 is installed in the first gantry 122 via the first lifting unit 124 and the first slider 123. By irradiating the workpiece W with laser light, the laser head 121 can perform drilling and cutting operations on the workpiece W.

[0023] The first gantry 122 is provided to be movable in the X direction above the workpiece W supported on the pallet 110. The first gantry 122 is a member that extends in the Y direction. The first gantry 122 is provided extending from the first frame F1 to the second frame F2 of the machine tool 1. The first gantry 122 moves in the X direction guided by X guides G1 provided on the upper surfaces of the first frame F1 and the second frame F2. The X guides G1 may be provided on the sides of the first frame F1 and the second frame F2.

[0024] The first slider 123 is provided above the workpiece W so as to be movable in the Y direction. The first slider 123 moves in the Y direction guided by a Y guide G2 provided on the upper surface of the first gantry 122. The Y guide G2 may be provided on the side of the first gantry 122. The first lifting unit 124 is a device provided above the workpiece W so as to be movable in the Z direction. The first lifting unit 124 is provided on the side of the first slider 123. The first lifting unit 124 moves in the Z direction guided by a guide unit G3 provided on the side of the first slider 123.

[0025] The laser head 121 is attached to the first lifting unit 124. The laser head 121 moves in the X direction above the workpiece W supported on the pallet 110 as the first gantry 122 moves in the X direction. The laser head 121 moves in the Y direction above the workpiece W supported on the pallet 110 as the first slider 123 moves in the Y direction. The laser head 121 moves in the Z direction above the workpiece W supported on the pallet 110 as the first lifting unit 124 moves in the Z direction.

[0026] The cutting apparatus 130 comprises a second gantry 131 and a cutting unit 200. The second gantry 131 is mounted above a workpiece W supported on a pallet 110 and is movable in the X direction. The second gantry 131 extends from the first frame F1 to the second frame F2 of the machine tool 1. The second gantry 131 moves in the X direction guided by an X guide G1. That is, the guide that guides the first gantry 122 and the guide that guides the second gantry 131 are shared (shared) by the X guide G1.

[0027] The cutting unit 200 is installed on the second gantry 131. The cutting unit 200 is installed on the second gantry 131 so as to be movable in the Y direction. The cutting unit 200 performs cutting while pressing down on the workpiece W placed on the pallet 110. The configuration of the cutting unit 200 will be described below.

[0028] Figure 2 is a schematic diagram of the main configuration of the cutting unit 200 according to this embodiment. Figure 3 is a detailed configuration diagram of the cutting unit 200 according to this embodiment. As shown in Figure 2, the cutting unit 200 includes a second slider (first direction moving body) 210, a second lifting unit (lifting unit) 215, a first direction motor 217, a cutting mechanism 220, and a workpiece holding mechanism 250. The second slider 210 is provided, for example, to be movable in the Y direction above the workpiece W. The second slider 210 moves in the Y direction guided by a Y guide G2 provided on the upper surface of the second gantry 131 shown in Figure 1. The Y guide G2 may be provided on the side surface of the second gantry 131.

[0029] The cutting unit 200 includes a first direction motor 217. The first direction motor 217 is supported, for example, by a second slider 210. The first direction motor 217 is a drive source for moving the second slider 210 in a first direction (for example, the Y direction) on the second gantry 131. Driven by the first direction motor 217, the second slider 210 is guided by a Y guide G2 provided on the upper surface of the second gantry 131 and moves in the Y direction. The first direction motor 217 is supported, for example, by the second slider 210.

[0030] The cutting mechanism 220 comprises a cutting body 221, a first cutting motor 223, a second cutting motor 224, and a cutting motor control unit 225. The cutting mechanism 220 (cutting spindle 232) is integrally provided with the second lifting unit 215. The second lifting unit 215 is fitted with a guide unit G3 provided in the Z direction on the side of the second slider 210, and is provided so as to be able to move relative to the second slider 210 in the Z direction, guided by the guide unit G3.

[0031] The cutting body 221 comprises a cutting tool 231 and a cutting spindle 232. The cutting body 221 moves in a first direction as the second slider 210 moves in a first direction. The cutting body 221 moves relative to the second slider 210 in the Z direction as the second lifting unit 215 moves. The cutting tool 231 is a tool that performs cutting operations on the workpiece W. Cutting operations include, for example, drilling, tapping, or counterboring. The cutting tool 231 is rotatably mounted on the tip of the cutting spindle 232. The cutting tool 231 is a rotary tool that performs cutting operations on the workpiece W by rotating itself. The cutting spindle 232 supports the cutting tool 231 so that it can rotate around its axis. The cutting spindle 232 is integrally mounted to the second lifting unit 215.

[0032] The first cutting motor 223 is a drive source for moving the cutting body 221 in the Z direction. The first cutting motor 223 raises and lowers the second lifting section 215, to which the cutting body 221 is attached, in the Z direction. The first cutting motor 223 is provided on the second slider 210. A shaft-shaped first power transmission section 400 is coaxially attached to the output shaft of the first cutting motor 223. The first power transmission section 400 is supported by the second slider 210 via a bearing 401. That is, the first power transmission section 400 is rotatably mounted on the second slider 210 around its axis. A thread is formed on a part of the first power transmission section 400 and functions as the screw shaft of a ball screw. A ball screw nut 216 is integrally provided on the second lifting section 215 and is screwed into the screw shaft of the first power transmission section 400.

[0033] The first power transmission unit 400 converts the rotational motion of the first cutting motor 223 into linear motion to move the second lifting unit 215 in the Z direction. That is, when the first power transmission unit 400 is rotated around its axis by the drive of the first cutting motor 223, the nut 216 screwed onto the screw shaft of the first power transmission unit 400 is moved in the Z direction. As a result, the second lifting unit 215, which is integrally provided with the nut 216, and thus the entire cutting body 221, are moved relative to the second slider 210 in the Z direction.

[0034] The second cutting motor 224 is a motor that rotates the cutting spindle 232. The second cutting motor 224 is attached to the cutting spindle 232. A power transmission mechanism (not shown) is provided between the second cutting motor 224 and the cutting tool 231 to transmit the rotational power of the second cutting motor 224 to the cutting tool 231.

[0035] The cutting motor control unit 225 controls the rotation of the first cutting motor 223 and the second cutting motor 224. The cutting motor control unit 225 controls the first cutting motor 223 to move the cutting body 221 in the Z direction during cutting. The cutting motor control unit 225 also rotates the cutting tool 231 by rotating the second cutting motor 224. By controlling the rotation of the first cutting motor 223 and the second cutting motor 224, the cutting motor control unit 225 can perform either or both oscillating cutting and step cutting on the workpiece W.

[0036] Oscillating cutting is a machining method in which chips are finely cut (divided) by oscillating a rotating cutting tool in the Z-direction, which is the machining direction. For example, the cutting motor control unit 225 rotates the cutting tool by controlling the second cutting motor 224. The cutting motor control unit 225 also moves the cutting tool 231 in the vertical direction (Z-direction) by controlling the first cutting motor 223, causing the cutting tool 231 to oscillate. For example, the cutting motor control unit 225 oscillates the cutting tool by outputting a sine wave command signal to the first cutting motor 223. The oscillating motion of the rotating cutting tool 231 finely cuts the chips.

[0037] Step machining is a machining method in which cutting is performed at predetermined intervals rather than continuously cutting the workpiece W to the target depth with the cutting tool 231 in one continuous motion. For example, the cutting motor control unit 225 rotates the cutting tool by controlling the second cutting motor 224. The cutting motor control unit 225 also controls the first cutting motor 223, repeatedly performing a step of lowering the cutting tool 231 relative to the workpiece W by a predetermined value and stopping it, thereby performing cutting at predetermined intervals. Alternatively, the cutting tool 231 may be moved upward to a position where it does not contact the workpiece W before cutting the workpiece W again with the cutting tool 231.

[0038] The workpiece holding mechanism 250 is provided on the second gantry 131 via the second slider 210. The workpiece holding mechanism 250 is attached to a different part of the second slider 210 than the cutting mechanism 220. The workpiece holding mechanism 250 holds the workpiece W, which is to be cut by the cutting mechanism 220, from above downwards. Holding the workpiece W from above downwards is sometimes referred to as "workpiece holding". The workpiece holding mechanism 250 includes, for example, a workpiece holding motor 300, a workpiece holding body 310, a power transmission mechanism 500, a locking mechanism 330, and a workpiece holding control unit 340.

[0039] The workpiece holding motor 300 is a drive source for moving the workpiece holding body 310 in the Z direction relative to the second slider 210. The workpiece holding motor 300 is, for example, a motor with variable thrust. The workpiece holding motor 300 is, for example, a servo motor. The workpiece holding motor 300 may also be a linear motor. As shown in Figure 3, the workpiece holding motor 300 is provided with a rotation detection unit 300S that detects the rotation of the workpiece holding motor 300. The rotation detection unit 300S outputs a detection signal corresponding to the rotation of the workpiece holding motor 300 to the workpiece holding control unit 340. The rotation detection unit 300S is, for example, an encoder. The workpiece holding motor 300 is supported, for example, by the second slider 210.

[0040] The workpiece holder body 310 includes a shaft-shaped second power transmission unit 501. The second power transmission unit 501 is integrally provided with a contact unit 322, which will be described later. A spline tooth 503 is formed on a part of the second power transmission unit 501. The second slider 210 has a spline groove 213 extending in the Z direction that meshes with the spline tooth 503 of the second power transmission unit 501, and these are spline-fitted to each other. As a result, the second power transmission unit 501 is provided so as to be axially movable relative to the second slider 210. A thread is formed on a part of the second power transmission unit 501, and it functions as the screw shaft of a ball screw. A ball screw nut 502 is screwed onto this screw shaft, forming a rotary ball screw. The nut 502 is connected to the output shaft of the workpiece holder motor 300 via a power transmission mechanism 500.

[0041] The power transmission mechanism 500 includes, for example, a first pulley 311, a second pulley 312, and a belt 314. The first pulley 311 is attached to the output shaft of the workpiece holding motor 300. The first pulley 311 rotates integrally with the output shaft of the workpiece holding motor 300. The second pulley 312 is attached to the nut 502. The second pulley 312 is provided integrally with the nut 502 and rotates coaxially with the nut 502. The belt 314 is a loop-shaped endless belt stretched between the first pulley 311 and the second pulley 312.

[0042] The first pulley 311 is attached to the output shaft of the workpiece holding motor 300. The first pulley 311 rotates integrally with the output shaft of the workpiece holding motor 300. The second pulley 312 is attached to the nut 502. The second pulley 312 is integrally provided with the nut 502 and rotates coaxially with the nut 502. The belt 314 is a loop-shaped endless belt stretched between the first pulley 311 and the second pulley 312.

[0043] The power transmission mechanism 500, the second power transmission part 501, and the nut 502 convert the rotational motion of the work holding motor 300 into linear motion to move the work holding main body part 310 in the Z direction. That is, when the nut 502 is rotated about the axis through the power transmission mechanism 500 by driving the work holding motor 300, the second power transmission part 501 screwed to the nut 502 on the screw shaft is moved in the Z direction. As a result, the contact part 322 provided integrally with the second power transmission part 501 and thus the entire work holding main body part 310 are relatively moved in the Z direction with respect to the second slider 210.

[0044] The work holding main body part 3_{10} includes a contact part 322. The contact part 322 is a member that presses against the work W placed on the pallet 110. That is, the contact part 322 contacts the upper surface of the work W placed on the pallet 110 and presses the upper surface of the work W with the lower surface of the contact part 322. The contact part 322 may be a member such as resin or rubber, for example. A through hole H through which the cutting tool 231 passes may be formed in the contact part 322. In this case, with the contact part 322 contacting the upper surface of the work W, the cutting tool 231 processes the work W through the through hole H.

[0045] As described above, the work holding main body part 310 relatively moves in the Z direction, which is the vertical direction, with respect to the second slider 210 according to the rotation of the work holding motor 300. When cutting is performed on the work W, the work holding main body part 310 descends. As a result, the contact part 322 provided at the end of the work holding main body part 310 on the work W side presses the upper surface of the work W placed on the pallet 110 downward.

[0046] The lock mechanism 330 shown in FIG. 3 locks the position of the work holding main body part 310 in the Z direction (hereinafter referred to as the "height position") so that the contact part 322 does not move in the Z direction. The height position is, for example, the position of the lower end of the work holding main body part 310. For example, the height position of the work holding main body part 310 is the position of the lower surface of the contact part 322 that contacts the upper surface of the work W in the Z direction.

[0047] The locking mechanism 330 may be, for example, a disk brake that brakes the rotation of the shaft-shaped second power transmission unit 501. When the disk brake operates and the rotation of the second power transmission unit 501 is braked, the rotation of the work holding motor 300 is locked, and the height position of the work holding main body 310 is locked. Note that the locking mechanism 330 is not limited to a disk brake, and is not particularly limited as long as it is a mechanism that locks the height position of the work holding main body 310 so that the work holding main body 310 does not move in the Z direction. For example, the locking mechanism 330 may be provided in the work holding motor 300.

[0048] The work holding control unit 340 controls the rotation of the work holding motor 300. The work holding control unit 340 controls the pressing force Fw with which the contact portion 322 presses the upper surface of the work W by controlling the rotation of the work holding motor 300. The work holding control unit 340 includes, for example, a servo amplifier. Note that the work holding control unit 340 and the work holding motor 300 may be integrated or separate. For example, the work holding control unit 340 may include a control IC such as a microcomputer and a driver IC that drives a plurality of switching elements for driving the work holding motor 300.

[0049] The work holding control unit 340 acquires information indicating the target value Fm of the pressing force Fw from an external device. The external device is, for example, the control device 140. The work holding control unit 340 rotates the work holding motor 300 to lower the work holding main body 310 in a state where the work W is placed on the pallet 110. The work holding control unit 340 constantly monitors the pressing force Fw directly or indirectly while lowering the work holding main body 310. For example, the work holding control unit 340 constantly monitors the output current output to the work holding motor 300, and may acquire the current pressing force Fw from information including the output current. The work holding control unit 340 rotates the work holding motor 300 until the pressing force Fw reaches the target value Fm.

[0050] The workpiece holding control unit 340 constantly acquires detection signals from the rotation detection unit 300S while lowering the workpiece holding body 310. Based on the detection signals from the rotation detection unit 300S, the workpiece holding control unit 340 acquires the height position of the workpiece holding body 310. In other words, the workpiece holding control unit 340 constantly acquires the current height position of the workpiece holding body 310 while lowering it. In this way, the workpiece holding control unit 340 lowers the workpiece holding body 310 while monitoring the holding force Fw and height position of the workpiece holding body 310 (contact portion 322).

[0051] The workpiece holding control unit 340 stops the rotation of the workpiece holding motor 300 when the contact portion 322 contacts the upper surface of the workpiece W and the holding force Fw reaches the target value Fm. As a result, the workpiece holding mechanism 250 can hold the workpiece W with a holding force of the target value Fm. The workpiece holding control unit 340 records the height position of the workpiece holding body 310 (hereinafter referred to as the "reached position") when the rotation of the workpiece holding motor 300 is stopped in a storage device within the workpiece holding control unit 340. The reached position is the height position of the workpiece holding body 310 when the holding force Fw reaches the target value Fm.

[0052] Here, from the time the contact portion 322 makes contact with the upper surface of the workpiece W until the pressing force Fw reaches the target value Fm, the contact portion 322 does not descend even if the workpiece pressing motor 300 rotates. Therefore, the reached position is the same as the height position when the contact portion 322 makes contact with the upper surface of the workpiece W, and corresponds to the position of the upper surface of the workpiece W in the height direction. The workpiece pressing control unit 340 transmits the reached position to the control device 140.

[0053] The workpiece holding control unit 340 may stop the rotation of the workpiece holding motor 300 and lock the height position of the contact portion 322 322 410 so that the height position of the contact portion 322 410 does not fluctuate when the holding force Fw reaches the target value Fm. For example, the workpiece holding control unit 340 may lock the height position of the contact portion 322 by electrically locking the rotation of the workpiece holding motor 300 so that it does not rotate. Alternatively, the workpiece holding control unit 340 may lock the height position of the contact portion 322 by activating the locking mechanism 330 via the control device 140. By locking the position of the contact portion 322, the height position of the contact portion 322 is maintained at the stopped position. This makes it possible to improve the thrust direction rigidity of the pallet (workpiece support) 110 that supports the workpiece W when cutting.

[0054] The control device 140 may include a processor such as a CPU (Central Processing Unit) or MPU (Micro Processing Unit) and non-volatile or volatile semiconductor memory (for example, RAM (Random Access Memory), ROM (Read Only Memory), flash memory, EPROM (Erasable Programmable Read Only Memory), or EEPROM (Electrically Erasable Programmable Read Only Memory)). The control device 140 controls the laser processing performed by the laser processing apparatus 120. The control device 140 causes the cutting mechanism 220 to perform cutting by transmitting command signals to the cutting motor control unit 225. The control device 140 may also control the loading of the pallet 110 into the machine tool 1 and the unloading of the pallet 110 from the machine tool 1.

[0055] The control device 140 communicates with the workpiece holding control unit 340 and the cutting motor control unit 225 to send and receive information. The control device 140 transmits information indicating the target value Fm of the holding force Fw to the workpiece holding control unit 340. The control device 140 may also initiate workpiece holding by the workpiece holding mechanism 250 by transmitting a command signal to the workpiece holding control unit 340 to instruct the start of workpiece holding. In this case, the command signal may include the target value Fm.

[0056] The control device 140 transmits information about the arrival position, which is the height position of the workpiece clamping body 310 when the clamping force Fw reaches the target value Fm, to the cutting motor control unit 225. The cutting motor control unit 225 sets the acquired arrival position as the position of the upper surface of the workpiece W (hereinafter referred to as the "upper surface position"). Then, the cutting motor control unit 225 performs a predetermined process using the set upper surface position of the workpiece W. The predetermined process includes, for example, controlling the feed amount of the cutting tool 231 and detecting the thickness of the workpiece W, or both, in cutting processes where precision in cutting depth is required, such as counterboring and countersinking. For example, the cutting motor control unit 225 controls the rotation of the first cutting motor 223 and the second cutting motor 224 to perform oscillating cutting or step cutting, and during the oscillating cutting or step cutting, it controls the feed amount of the cutting tool 231 based on the upper surface position of the workpiece W set according to the arrival position.

[0057] For example, the cutting motor control unit 225 controls the feed amount of the cutting tool 231 by controlling the rotation of the first cutting motor 223 based on the upper surface position of the workpiece W. Here, the upper surface position of the workpiece W may be set in advance, but this set value may differ from the actual upper surface position of the workpiece W. Therefore, the cutting motor control unit 225 can obtain a more accurate upper surface position of the workpiece W by setting the arrival position obtained from the workpiece holding control unit 340 as the upper surface position of the workpiece W.

[0058] The control device 140 may communicate with the workpiece holding control unit 340 and obtain information from the workpiece holding control unit 340 indicating that workpiece holding has been performed. Workpiece holding has been performed means that the contact portion 322 is pressing against the upper surface of the workpiece W with a holding force Fw at the target value Fm. The information indicating that workpiece holding has been performed is not particularly limited as long as it is information that allows one to understand that workpiece holding has been performed, but for example it may be information indicating that the holding force Fw has reached the target value Fm, or it may be information about the position where it has reached the target value. The control device 140 may activate the lock mechanism 330 to lock the height position of the workpiece holding body 310 when it obtains information from the workpiece holding control unit 340 indicating that workpiece holding has been performed.

[0059] An example of the target value Fm according to this embodiment will be described below. Figure 4 is a schematic diagram modeling the mechanism of the cutting unit according to this embodiment. Stiffness Kp indicates the vertical stiffness of the work support (the structure that supports the workpiece W, including the pallet 110) that supports the workpiece W. That is, stiffness Kp is the thrust direction stiffness of the work support with respect to the machining force (e.g., drill thrust) Fd. Stiffness Kw indicates the vertical stiffness of the workpiece holding mechanism 250. The machining force Fd is the downward force applied to the workpiece W from the cutting mechanism 220 during cutting. Here, the inventors have found that when the machining force Fd satisfies the conditions shown in equation (1), the stiffness of the work support becomes (Kp + Kw).

[0060] Fd<Fw・(Kp+Kw) / Kw…(1)

[0061] As a result, by adopting the workpiece holding mechanism 250 of this embodiment, the thrust rigidity of the workpiece support with respect to the machining force Fd can be improved. Furthermore, by adopting the workpiece holding mechanism 250 of this embodiment and satisfying the conditions shown in equation (1) above, machining operations that cannot be achieved when the thrust rigidity of the workpiece support is Kp become possible.

[0062] For example, if oscillating cutting or step machining is performed without the workpiece holding mechanism 250, the workpiece W may bend vertically. Figure 5 schematically shows what happens when cutting is performed without the workpiece holding mechanism 250. In the state shown in Figure 5, since there is no workpiece holding mechanism 250, the machining force Fd is received only by the rigidity Kp of the pallet 110, etc. Therefore, as shown by the dotted line in Figure 5, the workpiece W may bend and sink during cutting, or the pallet 110 may sink. In addition, if the machining force Fd is received only by the rigidity Kp, chatter may occur. Thus, performing oscillating cutting or step machining without the workpiece holding mechanism 250 can result in unstable machining.

[0063] On the other hand, as shown in Figure 4, when machining is performed with the workpiece W held down from above by the workpiece holding mechanism 250, the rigidity is increased to (Kp + Kw) by holding down the workpiece W, and machining that is not possible when the rigidity in the thrust direction is Kp becomes possible. In other words, deflection of the workpiece W and pallet 110 and the occurrence of the above-mentioned chatter during cutting can be suppressed, and stable machining can be achieved.

[0064] Furthermore, since the machining force Fd changes depending on the machining process, it is conceivable that the appropriate clamping force Fw may be adjusted for each machining process according to the machining force Fd. In other words, it is conceivable that the appropriate clamping force Fw may change depending on the machining process. In the workpiece clamping mechanism 250 of this embodiment, a workpiece clamping motor 300 is used as a drive source for moving the workpiece clamping body 310 in the vertical direction (Z direction), so the clamping force Fw can be accurately controlled. That is, by changing the target value Fm for each machining process, the appropriate clamping force Fw according to the machining force Fd can be easily and accurately controlled.

[0065] The operation of the cutting unit 200 according to this embodiment will be described below. Figure 6 is a diagram illustrating the flow of operation of the cutting unit 200 according to this embodiment. When the control device 140 performs cutting on the workpiece W placed on the pallet 110, it transmits a command signal including a target value Fm to the workpiece holding control unit 340.

[0066] The workpiece holding control unit 340 receives a command signal from the control device 140. Upon receiving the command signal, the workpiece holding control unit 340 obtains a target value Fm from the command signal (step S101). Upon obtaining the target value Fm, the workpiece holding control unit 340 rotates the workpiece holding motor 300 to start the downward movement of the workpiece holding body 310 (step S102). The workpiece holding control unit 340 determines whether the holding force Fw has reached the target value Fm (step S103). As an example, the workpiece holding control unit 340 obtains the current value of the output current to the workpiece holding motor 300 to obtain the current Fw. The contact portion 322 descends at a constant speed, for example, and contacts the upper surface of the workpiece W. When the workpiece holding member 410 contacts the upper surface of the workpiece W, the holding force Fw gradually increases until the holding force Fw reaches the target value Fm.

[0067] If the clamping force Fw has not reached the target value Fm, the workpiece clamping control unit 340 returns to step S102 and continues rotating the workpiece clamping motor 300. When the clamping force Fw reaches the target value Fm, the workpiece clamping control unit 340 stops rotating the workpiece clamping motor 300 (step S104). This puts the workpiece in a state where it is being held by the workpiece clamping mechanism 250. After stopping the rotation of the workpiece clamping motor 300, the workpiece clamping control unit 340 acquires the current height position of the workpiece clamping body 310, i.e., the stopping position (step S105). Then, the workpiece clamping control unit 340 transmits the stopping position information to the control device 140.

[0068] The control device 140 communicates with the workpiece holding control unit 340, and when it obtains information indicating that the workpiece has been held, it activates the locking mechanism 330 to lock the height position of the contact portion 322 so that the height position of the contact portion 322 does not move (step S106). When the cutting motor control unit 225 obtains information on the stop position via the control device 140, it sets that stop position as the upper surface position of the workpiece W (step S107). The cutting motor control unit 225 starts cutting using oscillating cutting or step cutting, and controls the feed amount of the cutting tool 231 based on the upper surface position of the workpiece W set in step S107 (step S108).

[0069] Step S106 may be performed before step S105. Also, if the locking mechanism 330 is not used, the workpiece holding control unit 340 may lock the rotation of the workpiece holding motor 300 after step S104 by energizing the workpiece holding motor 300 in a specific energizing pattern. This allows the workpiece holding control unit 340 to lock the position of the contact portion 322 so that its position does not change.

[0070] As described above, when the pressing force Fw reaches the target value Fm, the height position of the contact portion 322 is controlled so that it does not move from the stop position, but this is not limited to this. For example, the workpiece pressing control unit 340 may not lock the height position of the contact portion 322 to the stop position, but may always control the pressing force Fw to reach the target value Fm. That is, even after the pressing force Fw reaches the target value Fm, the workpiece pressing control unit 340 may always control the rotation of the workpiece pressing motor 300 so that the pressing force Fw reaches the target value Fm. For example, the workpiece pressing control unit 340 may perform torque control to keep the torque of the workpiece pressing motor 300 constant.

[0071] In this embodiment, the workpiece holding body 310 is not directly connected to the cutting body 221, which moves vertically during oscillating cutting or step machining, but is connected to the second slider 210. That is, the workpiece holding body 310 and the cutting body 221 are not directly connected to each other, but are connected to the second gantry (gantry) 131, which is a moving body that moves in a second direction, via the second slider 210. As a result, vibrations of the cutting body 221 when oscillating cutting or step machining is performed are not directly transmitted to the workpiece holding body 310. Consequently, vibrations of the workpiece holding body 310 are suppressed, and workpiece holding by the workpiece holding body 310 can be reliably performed.

[0072] The machine tool 1 may be equipped with a suction device that removes chips generated during cutting from the processing area R by sucking them up. The suction device removes chips generated during cutting from the processing area R by sucking up the air in the processing area R where cutting and laser processing are performed. As an example of this embodiment, if the machine tool 1 is a composite processing machine that performs laser processing and cutting on a workpiece W placed in the processing area R, and laser processing is performed after cutting, chips generated during cutting may have some effect on the laser processing. This problem is more of a concern in composite processing machines that perform laser processing and cutting in the same processing area R than in machine tools that perform cutting only. The machine tool 1 according to this embodiment is equipped with a suction device that sucks up chips in the processing area R, so that when laser processing and cutting are performed in the same processing area R, the effect of chips generated during cutting on the laser processing can be suppressed.

[0073] Here, when oscillating cutting or step machining is performed to cut chips, the workpiece W may bend in the vertical direction. Therefore, as shown in Figure 7, by holding the workpiece with the workpiece holding mechanism 250, it is possible to prevent the workpiece W from bending in the vertical direction. For example, as shown in Figure 7, when performing oscillating cutting in which the cutting body 221 having the cutting tool 231 is oscillated, if the workpiece is not held by the workpiece holding mechanism 250, the upper surface of the workpiece W may fluctuate between position TP1 and position TP2 due to the oscillating of the cutting tool 231.

[0074] Furthermore, even if a machine tool has a workpiece holding mechanism 250, if that workpiece holding mechanism 250 is directly connected to the cutting body 221 (for example, the cutting spindle 232), the workpiece holding mechanism 250 will also fluctuate significantly in the vertical direction in response to the oscillation of the cutting body 221. As a result, it may not be possible to hold the workpiece, and the upper surface of the workpiece W may fluctuate between position TP1 and position TP2.

[0075] Thus, if there is no workpiece holding mechanism 250, or if the workpiece holding mechanism 250 is directly connected to the cutting body 221, the workpiece W may bend vertically in response to vertical vibrations of the cutting body 221. The machine tool 1 of this embodiment has a workpiece holding mechanism 250 that holds the workpiece downwards from above. Furthermore, the workpiece holding mechanism 250 of this embodiment is not connected to the cutting body 221, but is connected to the second slider 210. As a result, vibrations of the workpiece holding mechanism 250 are suppressed during oscillating cutting, and the workpiece holding mechanism 250 can reliably hold the workpiece. Consequently, the machine tool 1 can prevent the workpiece W from bending vertically.

[0076] Furthermore, if the workpiece holding mechanism 250 presses the workpiece W too hard, the workpiece W may bend, which can reduce the accuracy of the cutting depth on the workpiece W. This is because the actual position of the workpiece W in the vertical direction deviates from the position estimated by the control side. Also, in the pincushion pallet (pallet 110) shown in Figure 1, which is compatible with laser processing, the surface of the workpiece W may be damaged if the force pressing down on the workpiece W is too strong. In this embodiment, an electric motor (workpiece holding motor 300) is used as the drive source for moving the contact portion 322 in the vertical direction instead of an air cylinder, and the pressing force is controlled by controlling the rotation of the workpiece holding motor 300. With this configuration, the pressing force can be controlled with high precision. As a result, the workpiece W can be held with an appropriate pressing force, which can prevent the workpiece W from bending due to excessive pressing.

[0077] The experimental results of the behavior of the workpiece W during machining are shown below. Machining was performed under the following four conditions (1) to (4), and the behavior of the workpiece W under each condition was plotted on a graph.

[0078] (1) No oscillating cutting / No workpiece holder (2) No oscillating cutting / Workpiece holder (3) Oscillating cutting / No workpiece holder (4) Oscillating cutting / Workpiece holder

[0079] Figure 8 shows the workpiece behavior under condition (1). Figure 9 shows the workpiece behavior under condition (2). Figure 10 shows the workpiece behavior under condition (3). Figure 11 shows the workpiece behavior under condition (4). Under each condition, the cutting speed is 100 m / min, the feed rate is 0.2 mm / rev, and the rotational speed is 2258 rpm. The workpiece W is made of SS400 and has a thickness of 9 mm. In Figures 8 to 11, the vertical axis represents the height of the workpiece top surface (mm), and the horizontal axis represents time (sec).

[0080] As shown in Figure 8, when cutting is performed without a workpiece holder and without oscillating cutting, the cutting tool 231 contacts the workpiece W at time t10 and then rapidly descends to perform the cutting. As shown at P10 in Figure 8, the drill thrust during this cutting process caused the workpiece W to sink by approximately 1.7 mm. Furthermore, when the workpiece W was penetrated by the cutting process at time t11, the workpiece W bounced up as shown at P11 in Figure 8.

[0081] As shown in Figure 9, when cutting is performed without oscillating cutting while the workpiece is held down, the workpiece is held down at time t20. When the workpiece is held down, the upper surface position of the workpiece W drops by about 1.8 mm, as shown at P20 in Figure 9. At time t21, after time t20, the cutting tool 231 contacts the workpiece W, and cutting is performed as the cutting tool 231 descends from there. As shown at P21 in Figure 9, the sinking of the workpiece W due to the drill thrust in this cutting process is about 0.1 mm, which is a significant improvement compared to condition (1) shown in Figure 8. Also, in Figure 9, the workpiece W is penetrated at time t22, but there is no bouncing of the workpiece W at the time of penetration. At time t23, the contact part 322 is raised and the workpiece is released.

[0082] As shown in Figure 9, the height of the upper surface of the workpiece W remains almost unchanged during a single cutting operation, even if the cutting tool 231 contacts the workpiece W or the cutting tool 231 penetrates the workpiece W from the start to the end of the workpiece clamping process. Furthermore, the bounce of the workpiece when the workpiece clamping is released is suppressed to about 6% of the bounce height when the workpiece W is not clamped (height of P11 at time t11 in Figure 8). As described above, compared to the state without workpiece clamping, the change in the upper surface position of the workpiece W during cutting was significantly suppressed when the workpiece clamping was performed.

[0083] As shown in Figure 10, when oscillating cutting is performed without a workpiece holder, the cutting tool 231 contacts the workpiece W at time t30, and cutting is performed as the cutting tool 231 descends while fluctuating slightly up and down. As shown at P30 in Figure 10, the upper surface of the workpiece W fluctuates up and down by a width of about 0.15 mm, following (being pulled by) the cutting tool 231 during oscillating cutting. Also, as shown at P30, the drill thrust caused the workpiece W to sink by about 1.7 ± 0.1 mm from its position before time t30. The workpiece W was penetrated at time t31, but there was almost no bouncing of the workpiece W.

[0084] As shown in Figure 11, when oscillating cutting is performed with the workpiece held down, the workpiece is held down at time t40. When the workpiece is held down, the upper surface position of the workpiece W drops by about 2.1 mm. At time t41, after time t40, the cutting tool 231 comes into contact with the workpiece W, and oscillating cutting is performed from there. As shown at P41 in Figure 11, the upper surface of the workpiece W moves up and down by a width of about 0.10 mm, following (being pulled by) the cutting tool 231 during oscillating cutting. This oscillating cutting finely cuts the chips. As shown at P41 in Figure 11, the sinking of the workpiece W due to the drill thrust in this cutting process is about 0.15 ± 0.05 mm, which is a significant improvement compared to condition (3) shown in Figure 10.

[0085] Furthermore, in Figure 11, the workpiece W penetrated at time t42, but no bouncing of the workpiece W occurred at the time of penetration. At time t43, the contact portion 322 was raised and the workpiece holder was released. As described above, in oscillating cutting with the workpiece holder, the fluctuation of the upper surface position of the workpiece W during oscillating cutting was suppressed by about 30% compared to oscillating cutting without the workpiece holder. In other words, the workpiece holder can suppress the fluctuation of the upper surface position of the workpiece W even in oscillating cutting where the upper surface position of the workpiece W tends to fluctuate in the vertical direction, enabling highly accurate oscillating cutting in the depth direction (downward direction).

[0086] Next, the movement of the oscillating cutting in this embodiment will be described. Figure 12 is a diagram showing the trajectories of the first end M1 and the second end M2 of the tip of the drill during oscillating cutting. The drill D is an example of a cutting tool 231. The dashed line on the graph in Figure 12 shows the trajectory of the first end M1. The dotted line on the graph in Figure 12 shows the trajectory of the second end M2. As shown in Figure 12, in oscillating cutting, the drill D, which is rotating at a constant speed, descends while oscillating in the vertical direction. Here, chip cutting occurs at the part 600 where the first end M1 and the second end M2 are in opposite directions (hereinafter referred to as the "reversal part").

[0087] Here, by pressing the workpiece W from above with the contact portion 322, the workpiece W becomes less susceptible to the effects of oscillating cutting, and fluctuations in the workpiece's height are suppressed. Therefore, chips are easier to cut during oscillating cutting. For example, if the workpiece is not held down, the workpiece W will rise and fall due to the vertical feeding motion of the drill D during oscillating cutting. As a result, the chips will not become thin (the reversal portion 600 shown in Figure 12 will disappear), and the chips may not be cut. In this embodiment, by pressing the workpiece W from above with the contact portion 322, the rigidity of the workpiece W and the pallet (workpiece support) 110 is temporarily improved. This makes it possible to suppress the rising and falling of the workpiece W during oscillating cutting, and enables the cutting of chips.

[0088] Furthermore, by pressing the workpiece W from above with the contact portion 322, the up-and-down movement of the workpiece W during oscillating cutting is suppressed, and the chips can be cut into smaller pieces. If the chip size is large, there is a risk that it cannot be sucked up by the suction device described above, but in this embodiment, the chip size can be reduced, making it easier to suck up the chips with the suction device. Chips can adversely affect laser processing, but by removing the chips with the suction device, the frequency of such adverse effects can be reduced. In addition, in this embodiment, by pressing the workpiece, the sinking of the workpiece W is suppressed, and the depth is stabilized in blind hole machining. Blind hole machining is a process in which the workpiece W is cut to a specific depth without penetrating it.

[0089] Furthermore, during laser processing, the laser beam may strike the projection 112P of the pallet 110, causing a portion of the projection 112P to be damaged. If a portion of the projection 112P is damaged, the height position of the upper surface of the workpiece W may deviate from the set value. Since the machine tool 1 detects the height of the upper surface of the workpiece W from the current height position of the contact portion 322, i.e., the stopping position, it can accurately determine the height position of the upper surface of the workpiece W even if a portion of the projection 112P is damaged and the height of the upper surface of the workpiece W deviates from the set value. As a result, the machine tool 1 can accurately detect the thickness of the workpiece W and accurately control the drill penetration amount and the depth of blind holes in blind hole processing.

[0090] The above embodiment discloses the following configuration: (Configuration 1) A cutting mechanism 220 having a cutting body 221 equipped with a cutting spindle 232 and a cutting tool 231 attached to the cutting spindle 232, and a first cutting motor 223 which is a drive source for moving the cutting body 221 in the vertical direction; a workpiece holding mechanism 250 having a workpiece holding body 310 equipped with a contact portion 322 that contacts the upper surface of the workpiece W, and a workpiece holding motor 300 which is a drive source for moving the workpiece holding body 310 in the vertical direction; and a first direction moving body (second slider 210) that is movable in a first direction which is perpendicular to the vertical direction, wherein the cutting mechanism 220 is mounted so as to be movable in the vertical direction relative to the first direction moving body (second slider 210), and is moved in the vertical direction relative to the first direction moving body (second slider 210) by the drive of the first cutting motor 223. The machine tool 1 is characterized in that the workpiece holding mechanism 250 is mounted on the first directional moving body (second slider 210) at a position different from the mounting position of the cutting mechanism 220 on the first directional moving body (second slider 210), so as to be movable in the vertical direction relative to the first directional moving body (second slider 210), and is moved in the vertical direction relative to the first directional moving body (second slider 210) by the drive of the workpiece holding motor 300, and the workpiece W is cut by the cutting mechanism 220 while the upper surface of the workpiece W is held down by the workpiece holding mechanism 250 with the contact portion 322. (Configuration 2) The machine tool 1 according to Configuration 1, comprising a gantry (second gantry 131) that is movable in a second direction perpendicular to both the first direction and the vertical direction, and the first directional moving body (second slider 210) is provided on the gantry (second gantry 131).(Configuration 3) The cutting mechanism 220 includes a lifting section (second lifting section 215) integrally provided with the cutting spindle 232, the lifting section (second lifting section 215) is fitted with a guide section G3 provided vertically on the side of the first directional moving body (second slider 210), and is provided so as to be able to move relative to the first directional moving body (second slider 210) in the vertical direction guided by the guide section G3, and includes a ball screw (first power transmission section 400) for converting the rotational power of the first cutting motor 223 into linear driving force and transmitting it to the lifting section (second lifting section 215), the nut 216 of the ball screw is provided integrally with the lifting section (second lifting section 215), and the screw shaft of the ball screw is connected to the output shaft of the first cutting motor 223, the machine tool 1 according to Configuration 1 or Configuration 2. (Configuration 4) The workpiece holding mechanism 250 includes a power transmission unit (second power transmission unit 501) integrally provided with the contact unit 322, a spline tooth 503 formed on a part of the power transmission unit (second power transmission unit 501), a spline groove 213 extending vertically on the first directional moving body (second slider 210) that meshes with the spline tooth 503 of the power transmission unit (second power transmission unit 501), and these are spline-fitted with each other so that the power transmission unit (second power transmission unit 501) is provided so that it can move relative to the first directional moving body (second slider 210) in the vertical direction, a ball screw for converting the rotational power of the workpiece holding motor 300 into linear driving force and transmitting it to the power transmission unit (second power transmission unit 501), and the screw shaft of the ball screw is formed on a part of the power transmission unit (second power transmission unit 501). The machine tool 1 according to any one of Configurations 1 to 3, wherein the nut 502 of the ball screw is connected to the output shaft of the workpiece holding motor 300 via a power transmission mechanism 500. (Configuration 5) The machine tool 1 according to any one of Configurations 1 to 4, comprising a workpiece holding control unit 340 that controls the workpiece holding motor 300, the workpiece holding control unit 340 obtains a target value of the holding force that holds the upper surface of the workpiece W with the contact portion 322 from an external device (control device 140), and rotates the workpiece holding motor 300 until the holding force reaches the target value.(Configuration 6) The machine tool 1 according to Configuration 5, wherein the workpiece holding control unit 340 stops the rotational operation of the workpiece holding motor 300 and locks the position of the contact portion 322 so that the position of the contact portion 322 does not change when the holding force reaches a target value. (Configuration 7) The machine tool 1 according to Configuration 5 or Configuration 6, further comprising a locking mechanism 330 that locks the position of the contact portion 322 so that the position of the contact portion 322 does not change when the holding force reaches a target value. (Configuration 8) The machine tool 1 according to any one of Configurations 5 to 7, wherein the workpiece holding motor 300 is provided with a rotation detection unit 300S that detects the rotation of the workpiece holding motor 300, and the workpiece holding control unit 340 acquires the position of the contact portion 322 in the height direction from the detection signal from the rotation detection unit 300S. (Configuration 9) The machine tool 1 according to Configuration 8, comprising a cutting motor control unit 225 that controls the first cutting motor 223, and the cutting motor control unit 225 sets the position of the contact portion 322 in the height direction acquired by the workpiece holding control unit 340 as the position of the upper surface of the workpiece W. (Configuration 10) The cutting motor control unit 225 performs a predetermined process based on the set position of the upper surface of the workpiece W, and the predetermined process includes either or both of the following: control of the feed amount of the cutting tool 231 and detection of the plate thickness of the workpiece W, the machine tool 1 according to Configuration 9. (Configuration 11) The workpiece holding motor 300 is a servo motor, the machine tool 1 according to any one of Configurations 1 to 10.

[0091] One or more of the requirements described in the embodiments described above may be omitted. Furthermore, the requirements described in the embodiments described above can be combined as appropriate. Also, the execution order of each procedure shown in this embodiment can be implemented in any order, as long as the results of the previous procedure are not used in the subsequent procedure. Furthermore, even if the operations in the embodiments described above are described using terms such as "first," "next," and "followed by," it is not essential to perform them in this order. In addition, to the extent permitted by law, the disclosures of Japanese Patent Application (JP 2024-175092) and all documents cited in the embodiments described above are incorporated into this specification as part of its description.

[0092] 1...Machine tool, 110...Pallet (work support), 131...Second gantry (gantry), 140...Control device (external device), 210...Second slider (first direction moving body), 213...Spline groove section, 215...Second lifting section (lifting section), 216...Nut, 220...Cutting mechanism, 221...Cutting main body section, 223...First cutting motor, 225...Cutting motor control section, 231...Cutting tool, 232...Cutting spindle, 250...Workpiece holding mechanism, 300...Workpiece holding motor, 300S...Rotation detection section, 310...Workpiece holding main body section, 322...Contact section, 330...Locking mechanism, 340...Workpiece holding control section, 400...First power transmission section (ball screw, screw shaft), 500...Power transmission mechanism, 501...Second power transmission section (power transmission section), 502...Nut, 503...Spline teeth, G3...Guide section

Claims

1. A machine tool comprising: a cutting mechanism having a cutting main body portion equipped with a cutting spindle and a cutting tool attached to the cutting spindle, and a first cutting motor which is a drive source for moving the cutting main body portion in the vertical direction; a workpiece holding mechanism having a workpiece holding main body portion equipped with a contact portion that contacts the upper surface of a workpiece, and a workpiece holding motor which is a drive source for moving the workpiece holding main body portion in the vertical direction; and a first direction moving body that is movable in a first direction which is perpendicular to the vertical direction, wherein the cutting mechanism is mounted on the first direction moving body so as to be movable in the vertical direction relative to the first direction moving body, and is moved in the vertical direction relative to the first direction moving body by the drive of the first cutting motor, the workpiece holding mechanism is mounted on the first direction moving body at a position different from the mounting position of the cutting mechanism, so as to be movable in the vertical direction relative to the first direction moving body, and is moved in the vertical direction relative to the first direction moving body by the drive of the workpiece holding motor, and the workpiece is cut by the cutting mechanism while the upper surface of the workpiece is held in place by the workpiece holding mechanism with the contact portion.

2. The machine tool according to claim 1, comprising a gantry movable in a second direction perpendicular to both the first direction and the vertical direction, wherein the first direction moving body is provided on the gantry.

3. The cutting mechanism comprises a lifting section integrally provided with the cutting spindle, the lifting section is fitted with a guide section provided vertically on the side of the first directional moving body, and is provided to be able to move relative to the first directional moving body in the vertical direction by being guided by the guide section, and comprises a ball screw for converting the rotational power of the first cutting motor into linear driving force and transmitting it to the lifting section, the nut of the ball screw is provided integrally with the lifting section, and the screw shaft of the ball screw is connected to the output shaft of the first cutting motor, the machine tool according to claim 1.

4. The machine tool according to claim 1, wherein the workpiece holding mechanism comprises a power transmission unit integrally provided with the contact unit, a part of the power transmission unit has spline teeth formed thereon, the first directional moving body has spline grooves extending vertically that mesh with the spline teeth of the power transmission unit, and these are spline-fitted with each other so that the power transmission unit is provided so that it can move vertically relative to the first directional moving body, and a ball screw is provided for converting the rotational power of the workpiece holding motor into linear driving force and transmitting it to the power transmission unit, the screw shaft of the ball screw is formed in a part of the power transmission unit, and the nut of the ball screw is connected to the output shaft of the workpiece holding motor via the power transmission mechanism.

5. The machine tool according to claim 1, further comprising a workpiece holding control unit that controls the workpiece holding motor, wherein the workpiece holding control unit obtains a target value for the holding force applied to the upper surface of the workpiece by the contact portion from an external device, and rotates the workpiece holding motor until the holding force reaches the target value.

6. The machine tool according to claim 5, wherein when the pressing force reaches the target value, the workpiece pressing control unit stops the rotational operation of the workpiece pressing motor and locks the position of the contact portion so that its position does not change.

7. The machine tool according to claim 5, further comprising a locking mechanism for locking the position of the contact portion so that its position does not change when the pressing force reaches the target value.

8. The machine tool according to claim 5, wherein the workpiece holding motor is provided with a rotation detection unit for detecting the rotation of the workpiece holding motor, and the workpiece holding control unit obtains the height position of the contact portion from the detection signal from the rotation detection unit.

9. The machine tool according to claim 8, further comprising a cutting motor control unit for controlling the first cutting motor, wherein the cutting motor control unit sets the height position of the contact portion obtained by the workpiece holding control unit as the position of the upper surface of the workpiece.

10. The cutting motor control unit performs a predetermined process based on the set position of the upper surface, the predetermined process includes either or both of the following: controlling the feed amount of the cutting tool and detecting the thickness of the workpiece, the machine tool according to claim 9.

11. The machine tool according to any one of claims 1 to 10, wherein the workpiece holding motor is a servo motor.

Images