Pallet posture changing device

Abstract

The present invention provides a pallet posture changing device (42) for changing, to a state including a horizontal state, a vertical state, and states therebetween, the posture of a pallet (76) which has an upper surface (76a), two engagement side surfaces (76e), and a contact side surface (76d) that is located therebetween, said pallet posture changing device (42) comprising: a base (60); a driving part (62) which is attached to the base (60) and which is configured to be able to rotate the pallet (76); a pair of arms (64) which are rotatably attached to the driving part (62), which extend so as to be parallel to the engagement side surfaces (76e) when facing the engagement side surfaces (76e), and which hold the pallet (76); receiving parts (74) which are disposed on the base (60) sides of the arms (64) and which have first pallet receiving surfaces (74a) that face the contact side surface (76d); and fingers (72) which are slidably disposed on the arms (64) and which engage with the pallet (76).

Description

Pallet position change device

[0001] The present invention relates to a pallet attitude changing device.

[0002] In a machine tool, when attempting to attach a pallet to a table in an upright position, a device for changing the pallet's position is required. In relation to this issue, Patent Documents 1 and 2 disclose pallet changer devices for C-axis tables. However, the pallet position changing device (setup stand) disclosed in Patent Document 1 is configured to clamp the underside of the pallet, which makes the clamping mechanism prone to catching chips generated during machining. Furthermore, because the underside of the pallet is clamped when setting up the pallet, it is also difficult to install devices for supplying media such as oil, air, and cutting fluid.

[0003] Furthermore, the pallet position changing device disclosed in Patent Document 2 is configured so that the clamping mechanism changes position by engaging the side of the pallet, rather than the underside. However, in the pallet position changing device disclosed in Patent Document 2, because the clamping mechanism engages with three side surfaces of the pallet, the clamping arm requires both a rotary shaft and a linear shaft due to the structure of the mechanism. As a result, it is difficult to configure the pallet position changing device compactly, and it becomes necessary to secure space in both the height and depth directions to place the pallet position changing device.

[0004] JP 2000-237927 A JP 2006-082164 A

[0005] In view of the above circumstances, an object of the present invention is to provide a pallet attitude changing device that uses a simple structure to change the attitude of a pallet while holding it, thereby enabling stable pallet transport.

[0006] According to one aspect of the present invention, there is provided a pallet position changing device for changing the position of a pallet having an upper surface on which workpieces and jigs are assembled, a lower surface, two engagement side surfaces in contact with the upper and lower surfaces, and an abutment side surface located between the two engagement side surfaces, between a horizontal state in which the upper surface of the pallet is moved toward a horizontal plane, and an upright state in which the upper surface of the pallet is moved toward a vertical plane, the pallet position changing device comprising: a base; a drive unit attached to the base and configured to rotate the pallet around a central axis of rotation to change the position; a pair of arms rotatably attached to the drive unit, extending so as to be parallel to the engagement side surfaces when facing the engagement side surfaces, and holding the pallet; a receiving portion disposed on the arm near the base, having a first pallet receiving surface facing the abutment side surfaces; and fingers slidably disposed on the arm, which move from a pallet engagement position to a pallet engagement position to engage with the pallet.

[0007] According to one aspect of the present invention, there is provided a machine tool comprising: a spindle on which a tool is attached; a table on which a pallet having a workpiece assembled thereon can be attached in an upright position; a pallet position changing device according to the present invention; a swivel arm having, on both ends, on the side of the pallet position changing device and the side of the spindle, a first pallet holding portion for receiving and delivering a first pallet in an upright position and a second pallet holding portion for receiving and delivering a second pallet in an upright position; and a pallet exchange device having a swivel drive unit for rotating the swivel arm around a swivel axis parallel to the vertical direction.

[0008] A pallet position changing device according to one aspect of the present invention includes a pair of arms rotatably attached to a drive unit, extending parallel to the engagement side when facing the engagement side, and holding a pallet; and fingers slidably disposed on the arms and moving from a pallet disengagement position to a pallet engagement position to engage with the pallet. Thus, the pallet position changing device can change the position of the pallet, including between a horizontal position and an upright position, by rotating the arms holding the pallet using the drive unit. Furthermore, the pair of arms can stably hold the pallet by engaging with two sides of the pallet, i.e., the engagement side, via the fingers. Such arms simplify the structure of the device while ensuring the effectiveness of the arm behavior. The pallet position changing device further includes a receiving portion disposed on the base side of the arm and having a first pallet receiving surface facing the abutment side located between the two engagement side. Therefore, when the pallet applies its own weight to the arm's central axis of rotation, i.e., the base side, by changing its position by rotating the arm and tilting its upper surface relative to the horizontal plane, the abutment side of the pallet can abut against the receiving part, and the pallet can be stably held as its position changes, including between a horizontal and an upright position.As described above, the pallet position changing device can change the position of a pallet while holding it using a simple structure, enabling stable pallet transport.

[0009] According to one aspect of the present invention, the machine tool includes a pallet position changing device having a pair of arms rotatably attached to a drive unit, extending parallel to the engagement side when facing the engagement side, and holding a pallet, and fingers slidably disposed on the arms and moving from a pallet disengagement position to a pallet engagement position to engage with the pallet. The pallet position changing device can thus change the position of the pallet, including between a horizontal position and an upright position, by rotating the arms holding the pallet using the drive unit. The pair of arms can also stably hold the pallet by engaging with two sides of the pallet, i.e., the engagement side, via the fingers. Such arms simplify the structure of the device while ensuring the effectiveness of the arm behavior. The pallet position changing device also includes a receiving portion disposed on the base side of the arm and having a first pallet receiving surface facing the abutment side located between the two engagement side. Therefore, when the pallet's position is changed by rotating the arm and its upper surface is tilted relative to the horizontal plane, and the pallet exerts its own weight toward the arm's central axis of rotation, i.e., the base, the abutment side of the pallet can abut against the receiving portion, allowing the pallet to be stably held as it changes position, including between a horizontal position and an upright position. The machine tool also includes a pallet exchange device having a swivel arm with a first pallet holding portion for receiving and delivering a first pallet in an upright position and a second pallet holding portion for receiving and delivering a second pallet in an upright position, at both ends. Therefore, the pallet whose position has been changed by the pallet position changing device can be stably transported to the spindle. This allows a machine tool equipped with the pallet position changing device and pallet exchange device to change the position of a pallet while holding it using a simple structure, enabling stable pallet transport.

[0010] FIG. 1 shows a plan view of a machine tool equipped with a pallet orientation changing device according to this embodiment. FIG. 2 shows a perspective view of the pallet orientation changing device according to this embodiment. FIG. 3 shows a view of the fingers engaged with the pins at the pallet engagement position, as viewed from the longitudinal direction of the arm. FIG. 4 shows a side view of a pallet brought in from outside the machine tool. FIG. 5 shows a side view of the arm rotated to the engagement position and positioned relative to the pallet. FIG. 6 shows a side view of the pallet with the fingers engaged with the pins, actuated to the pallet engagement position. FIG. 7 shows a side view of the pallet whose orientation has been changed to an upright position. FIG. 8 shows a side view of a pallet held by an APC arm. FIG. 9 shows a side view of a pallet in an upright position with the fingers actuated to a pallet disengagement position. FIG. 10 shows a side view of the arm rotated to a standby position. FIG. 11 shows a side view of a second pallet replaced by the APC arm. FIG. 12 shows a side view of the arm positioning the fingers to engage with the second pallet in an upright position. FIG. 13 shows a side view of the second pallet with the fingers actuated to the pallet engaging position and engaging with the pins. FIG. 14 shows a side view of the second pallet with the APC arm lowered to release its hold by the second pallet holder. FIG. 15 shows a side view of the second pallet moved to a horizontal position. FIG. 16 shows a side view of the second pallet with the fingers actuated to the pallet disengagement position and disengaged from the pins. FIG. 17 shows a side view of the arm moved to the retracted position. FIG. 18 shows a side view of the second pallet being transported outside the machine tool. FIG. 19 shows a side view of the media supply unit connected to the second pallet. FIG. 20A shows a side view of the media supply unit positioned below the rail. FIG. 20B shows a side view of the media supply unit raised and connected to the pallet. FIG. 20C shows a side view of the media supply unit lowered and released from its connection with the pallet. FIG. 20D shows a side view of the arm holding the pallet. FIG. 21 is a side view of a pallet attitude changing device according to a modified example.

[0011] Hereinafter, a machine tool equipped with a pallet attitude changing device according to an embodiment will be described with reference to the accompanying drawings. Similar or corresponding elements are given the same reference numerals, and duplicated explanations will be omitted. For ease of understanding, the scale of the drawings may be changed.

[0012] 1 shows a schematic plan view of a machine tool 10 equipped with a pallet orientation changing device 42 according to this embodiment. The machine tool 10 is covered by a splash guard 16 to prevent chips generated during machining from scattering, etc. The interior of the splash guard 16 is divided into a machining chamber 12 and a setup chamber 14 by a pivot door 46 that is rotatable (pivotable) about a pivot axis R1 (see FIG. 4) that is parallel to the vertical direction. An operator door 12a and a setup chamber door 14a are also attached to the splash guard 16 to allow an operator (not shown) to access the interior of the machining chamber 12 and the setup chamber 14 from the outside.

[0013] The machining chamber 12 is equipped with equipment such as a spindle 26 and a C-axis rotary table 36 for machining workpieces W1 and W2 (see FIGS. 4 and 11 ). A pair of X-axis linear guides 30 extending in the left-right direction, i.e., along the X-axis, is provided on the upper surface of a bed 18, which is placed on the floor of a factory or the like where the machine tool 10 is installed. A column 22 is uprightly disposed on the X-axis linear guides 30, allowing it to reciprocate along the X-axis linear guides. The machine tool 10 also has a pair of Y-axis linear guides (not shown) extending vertically (in the Y-axis direction, perpendicular to the plane of FIG. 1 ) on the front of the column 22. A saddle 24 is disposed on the Y-axis linear guides, allowing it to reciprocate along the Y-axis linear guides. A spindle 26 rotatable about a horizontal central axis is disposed in front of the saddle 24. Furthermore, a tool 28 for machining the workpieces W1 and W2 is detachably attached to the front side (the setup room 14 side) of the spindle 26. The machine tool 10 is electrically connected to the spindle 26 and is equipped with an NC device (not shown) for controlling machining, and is configured to be able to control the machining of the workpieces W1 and W2 using the tool 28.

[0014] A pair of Z-axis linear guides 38 extend along the front-to-rear direction, i.e., the Z-axis direction, on the upper surface of the bed 18 in front of the spindle 26 of the machine tool 10. A Z-axis table 32 is disposed on the Z-axis linear guides 38, allowing it to reciprocate along the Z-axis linear guides 38. A B-axis rotary table 34 is disposed on the Z-axis table 32, allowing it to rotate about a rotation axis (about the B-axis) parallel to the vertical direction. A C-axis rotary table 36 is disposed on the B-axis rotary table 34, and serves as a table configured so that the top surface 76a (see FIG. 2) of a pallet 76 (first pallet) mounted thereon is positioned upright on the vertical plane. The C-axis rotary table 36 is also configured to rotate the mounted workpieces W1 and W2 and the pallet 76 about a central axis (about the C-axis) that is horizontal. In this manner, the Z-axis table 32, the B-axis rotary table 34, and the C-axis rotary table 36 allow the workpieces W1 and W2 and the tool 28 to be aligned. Furthermore, the machine tool 10 is equipped with an X-axis feed device for driving the column 22 along the X-axis linear guide 30, a Y-axis feed device for driving the saddle 24 along the Y-axis linear guide, and a Z-axis feed device for driving the Z-axis table 32 along the Z-axis linear guide 38 (all not shown).

[0015] A setup station 40 is disposed within the setup chamber 14 for performing setup such as attaching (assembling) the unmachined workpiece W1 to the pallet 76 and removing the machined workpiece W2. The setup station 40 includes a pallet position changing device 42 for changing the position of the workpieces W1 and W2 attached to the pallet 76. The setup station 40 also includes a medium supply unit 80 for supplying a medium, including oil, air, and cutting fluid, to the pallet 76 and any of the workpieces W1 and W2 and / or jigs attached to the pallet 76. The medium supply unit 80 is configured to supply the medium via a coupler 100 (see FIG. 20A) attached to the underside 76b (see FIG. 2) of the pallet 76.

[0016] The pivoting door 46, which separates the machining chamber 12 and the setup chamber 14, extends vertically between the side walls of the splash guard 16 and is placed on a pivoting door holder 48 located below the side walls of the splash guard 16. Specifically, the pivoting door 46 and the pivoting door holder 48 are placed in a mated state with mating portions (not shown) formed on both the pivoting door 46 and the pivoting door holder 48 fitted together. The pivoting door 46 has a width direction that is the left-right direction when viewed from the front of the machine, i.e., the X-axis direction. A pallet exchange device 44 is located below the pivoting door 46, either separately from the pivoting door 46 or in conjunction with the pivoting door 46, and is configured to be pivotable about a pivot axis R1 that is parallel to the vertical direction (Y-axis direction). The pallet exchange device 44 includes an APC arm 50 as a rotating arm that is rotatable about a rotation axis RA2 parallel to the vertical direction (Y-axis direction) to transfer the unmachined workpiece W1 and the machined workpiece W2 between the setup chamber 14 and the machining chamber 12, and an APC arm drive mechanism 56 as a rotation drive unit for rotating the APC arm 50. The APC arm 50 is configured to be movable up and down in the vertical direction (Y1 direction in FIG. 2 ) by the APC arm drive mechanism 56. The APC arm drive mechanism 56 has an actuator (not shown) such as a hydraulic cylinder, a pneumatic cylinder, or a servo motor that enables fine operation setting and adjustment, and the actuator rotates and moves the APC arm 50 up and down. The actuator is configured to be controllable by a control device (not shown) disposed in the machine tool 10. Note that "APC" is an abbreviation for "Automatic Pallet Change." While the pivoting door holder 48 has been described as being located on the lower side of the side wall of the splash guard 16, the present invention is not limited to this and the pivoting door holder may be installed directly on the bed or floor. Furthermore, the pivoting door holder may hold the pivoting door in a manner other than by a fitting portion, as long as it can regulate the movement of the pivoting door in the rotational direction and the direction of gravity in place of the APC arm when the APC arm is lowered and not engaged with the pivoting door.

[0017] When the APC arm 50 is not transferring workpieces W1, W2, it is stored in a storage position with its longitudinal direction aligned with the width direction of the swing door 46, i.e., the X-axis direction. A chip cover 52 is formed on the lower side of the swing door 46, and has an inclined surface that extends toward the setup station 40 and the machining chamber 12 (front and rear sides in the Z-axis direction) as it moves downward (vertically downward). The chip cover 52 is formed to cover the APC arm 50 engaged with the swing door 46 from above, and can prevent or suppress chips and the like generated during machining in the machining chamber 12 from adhering to the APC arm 50.

[0018] As shown in FIG. 2 , the APC arm 50 is provided with a first pallet holder 82 and a second pallet holder 84 at both longitudinal ends thereof for holding a pallet 76. The first pallet holder 82 and the second pallet holder 84 have columnar members at both widthwise ends of the APC arm 50 and are concave-shaped when viewed in the longitudinal direction of the APC arm 50. A holding member 76f is attached to an abutment side surface 76d of the pallet 76, which is the side surface facing the APC arm 50. The holding member 76f is formed in a plate shape with dimensions that allow it to fit into the concave portions of the first pallet holder 82 and the second pallet holder 84. Therefore, when the pallet 76 is in an upright position, the holding member 76f fits into the concave portions of the first pallet holder 82 and the second pallet holder 84, and the upper surfaces of the columnar members at both ends of the first pallet holder 82 and the second pallet holder 84 abut against the abutment side surface 76d of the pallet 76. This allows the APC arm 50 to support the pallet 76 and hold the upright pallet 76, the jig 96 attached thereto, and the workpieces W1 and W2 (see FIGS. 4 and 11).

[0019] Note that, here, the first pallet holding portion 82 and the second pallet holding portion 84 of the APC arm 50 are described as supporting the pallet 76 by fitting the holding members 76f into the recessed portions and abutting the upper surfaces of the columnar members at both ends against the abutment side surfaces 76d of the pallet 76, but this is not limitative. For example, the holding portions of the APC arm may be configured with a mechanism that clamps the upper and lower surfaces of the pallet.

[0020] As shown in FIG. 1 , the APC arm 50 and the pivoting door 46 can be engaged with each other by an engagement mechanism 54. The engagement mechanism 54 includes an engagement pin 54a serving as an engaging portion on the APC arm 50 side and a guide hole 46a serving as an engaged portion on the pivoting door 46 side. The engagement pin 54a is formed on the upper surface of the APC arm 50 and extends upward. Therefore, the engagement pin 54a moves up and down in conjunction with the up and down movement of the APC arm 50. The guide hole 46a is formed at the bottom of the pivoting door 46 so as to be able to engage with the inserted engagement pin 54a. Here, two engagement pins 54a are arranged at equal intervals of 180° around the pivot axis RA2 of the APC arm 50, and four guide holes 46a are formed at equal intervals of 90° around the pivot axis RA2 of the APC arm 50 to correspond to the engagement pins 54a. It is sufficient to provide at least one pair of engagement pins 54a and guide holes 46a. The engagement mechanism 54 is configured so that the engagement pin 54a and the guide hole 46a can be engaged or disengaged, thereby engaging the APC arm 50 and the pivoting door 46. Therefore, when the APC arm 50 and the pivoting door 46 are engaged, the APC arm 50 and the pivoting door 46 can be pivoted together. Furthermore, when the APC arm 50 and the pivoting door 46 are disengaged, the APC arm 50 can be pivoted independently to transfer a pallet 76, 94 to the APC arm 50 or to store the APC arm 50 in a storage position when it is not transferring a pallet. Note that, in this description, the APC arm 50 has the engagement pin 54a and the pivoting door 46 has a guide hole 46a formed in its bottom. However, this is not limiting. For example, the pivoting door may have an engagement pin extending from its bottom, or the APC arm may have a guide hole formed therein. In addition to the combination of the engagement pin 54a and the guide hole 46a, the engagement pin may be configured to engage / disengage with a claw or the like disposed on both the APC arm and the swing door. Furthermore, the engagement pin is not limited to being rod-shaped or column-shaped, and may be configured to be movable up and down using, for example, a drive mechanism disposed in the engagement mechanism.

[0021] Specifically, the pallet exchange device 44 operates as follows. When the transfer of the pallet 76 begins in the machine tool 10, the APC arm drive mechanism 56 lowers the APC arm 50, which is in the storage position. At this time, the engagement pin 54a of the engagement mechanism 54 disengages from the guide hole 46a, thereby disengaging the pivoting door 46 from the APC arm 50, and the pivoting door 46 is fitted into the pivoting door holder 48 and placed thereon. As the APC arm 50 lowers, the APC arm drive mechanism 56 rotates the APC arm 50 by 90 degrees (or 270 degrees). As a result, the first pallet holder 82 and the second pallet holder 84 of the APC arm 50 move along the rotation trajectory TR1 (see FIG. 1) toward the C-axis rotary table 36 and the pallet orientation changing device 42, and the longitudinal direction of the APC arm 50 becomes aligned with the Z-axis direction.

[0022] When the first pallet holder 82 and the second pallet holder 84 move toward the C-axis rotary table 36 and the pallet attitude changing device 42, the APC arm drive mechanism 56 raises the APC arm 50. As the APC arm 50 rises, the engagement pin 54a of the engagement mechanism 54 is inserted into and engaged with the guide hole 46a. This engages the revolving door 46 with the APC arm 50, and the revolving door 46 is loaded onto the APC arm 50 instead of the revolving door holder 48.

[0023] Once the APC arm 50 has loaded the pivoting door 46, the APC arm drive mechanism 56 raises the pivoting door 46 and the APC arm 50. This allows the holding members 76f of the pallet 76 to fit into the recessed portions of the first pallet holder 82 and the second pallet holder 84, and the columnar members at both ends to abut against the abutment side surfaces 76d of the pallet 76, thereby holding the pallet 76. The pallet 76 is then transferred from the C-axis rotary table 36 and the pallet position change device 42 to the APC arm 50. After transferring the pallet 76 to the APC arm 50, the C-axis rotary table 36 and the pallet position change device 42 retract to a standby position where they do not interfere with the pivoting APC arm 50 or the pivoting door 46. The APC arm 50 then pivots them 180 degrees together. This allows the pallet 76 held by the APC arm 50 to be swapped between the machining chamber 12 and the setup room 14. Once the pallet 76 has been replaced, the C-axis rotary table 36 and / or the arm 64 of the pallet position changing device 42 move from the standby position to the pallet transfer position to hold the replaced pallet 76, 94. Furthermore, the APC arm drive mechanism 56 lowers the pivoting door 46 and the APC arm 50 holding the pallet 76, and the pivoting door 46, which was previously only loaded on the APC arm 50, is placed in a state where it is fitted into the pivoting door holder 48. Furthermore, the engagement pin 54a of the engagement mechanism 54 is pulled out of the guide hole 46a, and the engagement is released. After lowering the APC arm 50, the APC arm drive mechanism 56 rotates 90 degrees to move the first pallet holder 82 and the second pallet holder 84 below the pivoting door 46. When the first pallet holder 82 and the second pallet holder 84 move below the pivoting door 46, the APC arm drive mechanism 56 raises the APC arm 50, and the pivoting door 46 is loaded onto the APC arm 50 instead of the pivoting door holder 48. Furthermore, the engagement pin 54a of the engagement mechanism 54 is inserted into the guide hole 46a, and they engage. This causes the APC arm 50 to be stored in the storage position below the pivoting door 46.

[0024] As shown in FIG. 2 , the setup station 40 is provided with a pallet position changing device 42 for transferring a pallet 76, on which the pre-machined workpiece W1 and the machined workpiece W2 (see FIGS. 4 and 11 ) have been mounted, to and from the APC arm 50. The pallet 76 is formed in a plate shape having an upper surface 76a on which the workpieces W1 and W2 and the jig 96 (see FIG. 4 ) are mounted, and a lower surface 76b. The pallet 76 also has two engaging side surfaces 76e that are in contact with the upper surface 76a and the lower surface 76b and are located on the outer side of the pallet 76 in the X-axis direction, an abutting side surface 76d that is located between the two engaging side surfaces 76e, is located on the rear side of the pallet 76 in the Z-axis direction, and faces the APC arm 50, and a front side surface 76c that is located on the front side of the pallet 76 in the Z-axis direction and faces the setup chamber door 14a. Furthermore, the two engaging side surfaces 76e are integrally formed with the pallet 76 and have pins 78 that extend outward, i.e., outward in the X-axis direction. Here, two cylindrical pins 78 extending along the surface direction of the engagement side surface 76e are formed on each engagement side surface 76e. The two pins 78 are formed at intervals, one on each end side of the engagement side surface 76e in the longitudinal direction (Z-axis direction). Note that one pin may be formed on each engagement side surface, and the pins may be formed in a shape other than a cylindrical shape, such as a rectangular prism or a triangular prism.

[0025] An operator who places a pallet 76 in the setup station 40 of the setup chamber 14 and assembles a workpiece W1 and a jig 96 thereon places the pallet 76 on the media supply unit 80 in a horizontal position with the upper surface 76a of the pallet 76 facing the horizontal plane. To transfer the pallet 76 between the setup station 40 and the C-axis rotary table 36 to which the pallet 76 is attached in an upright position, the pallet position changing device 42 is configured to hold the pallet 76 and change its position, including between a horizontal position and an upright position. Specifically, the pallet position changing device 42 includes a base 60 disposed along the X-axis direction and forward of the pivot door 46 and the APC arm 50 in the Z-axis direction; a drive unit 62 attached to the base 60 and configured so that its rotation axis extending along the X-axis direction (horizontal direction) is rotatable about a rotation center axis RA1 (in the R1 direction); and a pair of arms 64 rotatably attached to the drive unit 62 and extending parallel to the two engagement side surfaces 76e when facing the two engagement side surfaces 76e, thereby being able to hold the pallet 76. 4, the base 60 extends forward in the Z axis direction (toward the setup chamber door 14a) from the outer periphery of the APC arm drive mechanism 56, which is disposed at the rotation center position of the APC arm 50. Therefore, the base 60 can be disposed inside the rotation trajectory TR1 of the APC arm 50 in a plan view, and chips can be prevented from falling directly onto the base 60 when the APC arm 50 rotates while holding the pallet 76 on which the workpieces W1 and W2 are mounted at its end.

[0026] The drive unit 62 has an actuator (not shown) such as a hydraulic cylinder, a pneumatic cylinder, or a servo motor that allows for fine operation setting and adjustment, and the actuator rotates the rotation shaft. The actuator is configured to be controllable by a control device (not shown) arranged in the machine tool 10. Furthermore, as will be described later, the pallet position changing device 42 is configured to be able to position (stop) the arm 64 not only between the upright position and the horizontal position, but also by rotating and positioning the arm 64 from the upright position in the upright position to a retracted position beyond the engagement position in the horizontal position. The pallet position changing device 42 is also configured to be able to position (stop) the arm 64 at an intermediate position, such as a standby position between the upright position and the engagement position.

[0027] In the following description, the pallet 76 is assumed to be square in plan view, with two parallel engagement sides 76e held by a pair of parallel arms 64; however, this is not limited to this. For example, the pallet may have chamfered corners or may have a shape other than a square, such as an octagonal or round shape in plan view. Furthermore, even if the pallet has a shape other than a square and the two engagement sides are not parallel, the pair of arms may not be parallel to each other, for example, extending in a V-shape in plan view so as to be parallel to the two engagement sides. If the pallet is round, the arms may be curved to fit the outer shape of the pallet.

[0028] 2, the arm 64 has an arm base end 66 that is connected to the rotation shaft of the drive unit 62, and an arm engaging unit 68 that extends linearly from an outer portion of the arm base end 66 in the X-axis direction so as to face the engaging side surface 76e. A receiving portion 74 is formed on the inner side in the X-axis direction of the arm base end 66, which is on the base 60 side of the arm 64, at a position that faces the abutting side surface 76d when the arm 64 holds a pallet 76. The receiving portion 74 is formed in an L-shape or an inverted L-shape when viewed from the side of the machine tool 10 (outside in the X-axis direction) in a horizontal state, and has a planar first pallet receiving surface 74a that extends perpendicular to the arm 64 and a planar second pallet receiving surface 74b that extends along the longitudinal direction of the arm 64, and is sized so that the abutting side surface 76d can abut against the first pallet receiving surface 74a and the lower surface 76b can abut against the second pallet receiving surface 74b. The first and second pallet support surfaces do not need to be precisely sized, but only need to be formed to a degree that allows them to abut against the pallet and reliably support the weight of the pallet. Therefore, the first and second pallet support surfaces are not limited to flat surfaces, and may be formed, for example, in a curved shape or a polygonal pyramid shape, thereby supporting the pallet in a state of point contact or line contact.

[0029] Each arm 64 includes two slides 70, each located at both longitudinal ends of the arm engagement portion 68, i.e., both ends in the Z-axis direction, and configured to slide along the longitudinal direction of the arm engagement portion 68. Furthermore, each of the two slides 70 is equipped with a finger 72 for engaging with a pallet 76. The spacing between the two fingers 72 corresponds to the spacing between the two pins 78. A rod disposed within the arm engagement portion 68 is integrally connected to the two slides 70, and the rod is connected to an actuator such as a hydraulic cylinder, a pneumatic cylinder, or a servo motor that enables fine operation setting and adjustment (all not shown). Therefore, the slides 70 and the fingers 72 can be moved in the same direction between a pallet engagement position and a pallet disengagement position in response to the actuation of the rod by the actuator. Here, the pallet engagement position is configured to be closer to the arm base end 66 than the pallet disengagement position. Furthermore, the actuators that operate the slides 70 and the fingers 72 are configured to be controllable by a control device (not shown) disposed in the machine tool 10. As shown in FIG. 3 , the finger 72 has a central portion 72c that faces the engagement side surface 76e when the arm engagement portion 68 is moved laterally toward the pallet 76 to hold the pallet 76, an upper surface-side restricting portion 72a formed on the upper side (upper surface 76a side) of the central portion 72c, and a lower surface-side restricting portion 72b formed on the lower side (lower surface 76b side) of the central portion 72c. Therefore, a groove 72d is formed by the central portion 72c, the upper surface-side restricting portion 72a, and the lower surface-side restricting portion 72b. When the finger 72 is viewed from the longitudinal direction of the arm 64, the groove 72d is formed in a concave shape facing the pallet 76. The groove 72d is formed so that its depth direction coincides with the extension direction of the pin 78. Therefore, by moving the arm engagement portion 68 to the side of the engagement side surface 76e of the pallet 76 and moving it from a position where the finger 72 and the pin 78 do not face each other along the X-axis direction (pallet disengagement position) to a position where the finger 72 and the pin 78 face each other along the X-axis direction (pallet engagement position) (sliding along the XF1 direction), the finger 72 can be engaged with the pallet 76. This allows the arm 64 to stably hold the pallet 76.Furthermore, since the concave groove portion 72d is open to the outside of the finger 72, it is possible to prevent or suppress chips generated by machining from getting caught between the finger 72 and the pin 78.

[0030] Here, the finger 72 is described as being formed in a concave shape facing the pallet 76 when viewed from the longitudinal direction of the arm 64, but this is not limited to this and any shape that can engage with the pin will suffice. For example, the finger may be formed in another shape, such as an open V-shape facing the pin when viewed from the longitudinal direction of the arm.

[0031] Furthermore, an arm protrusion 86 (see FIG. 4) extending toward the engagement side surface 76e is formed on the inside in the width direction facing the engagement side surface 76e of the arm engagement portion 68, i.e., on the inside in the X-axis direction. A pallet groove 88 is formed in the engagement side surface 76e so as to be recessed inward of the pallet 76, allowing the arm protrusion 86 to be inserted. This allows the arm 64 to hold the pallet 76 using both the fingers 72 and the arm protrusion 86, thereby stably holding the pallet 76. As another example, a similar effect can be achieved by forming a pallet protrusion on the engagement side surface of the pallet and an arm groove on the arm, reversing the relationship of the protrusions and recesses.

[0032] Note that, here, the finger 72 of the arm engaging portion 68 is described as being configured to be slidable between a pallet disengagement position and a pallet engagement position along the longitudinal direction of the arm engaging portion 68, i.e., the Z-axis direction (XF1 direction in FIG. 3), but this is not limiting, and the finger may be configured to hold the pallet by sliding in the X-axis direction, i.e., the direction facing the pallet (XF2 direction in FIG. 3). In such a configuration, the finger does not displace in the longitudinal direction of the arm, so the arm can be made space-saving in the longitudinal direction and can be configured compactly.

[0033] The effects of the pallet attitude changing device 42 of the machine tool 10 according to this embodiment will be described below through an explanation of the setup of the pallet 76 shown in Figures 4 to 20. Note that the side views of the pallet attitude changing device 42 and the like shown in Figures 4 to 20 are schematic views for explaining the effects of these devices, and in order to make the drawings easier to see, it should be noted that parts that are not directly visible in actual side view because they are hidden by the arm 64 (fingers 72, receiving portions 74, arm protrusions 86, etc.) are drawn in solid lines.

[0034] FIG. 4 shows a state in which a pallet 76 to which a jig 96 and a pre-machined workpiece W1 are attached is being carried in from outside the machine tool 10. Here, the pallet 76 (shown by the dotted line in FIG. 4 ) is loaded horizontally from outside the machine tool 10 through the setup chamber door 14a toward the setup station 40, i.e., the pallet position changing device 42, on rails 90 arranged on the upper surface of the bed 18 directly below the pallet position changing device 42. The pallet 76 may be loaded in a horizontal position through the setup chamber door 14a. The pallet 76 may also be loaded vertically using a transport device installed above the machine tool, or using the forks of a forked transport vehicle. The loaded pallet 76 stops sliding when it hits a stopper 92 formed at the end of the rail 90, and is positioned at the horizontal setup position. At this time, the arm 64 is positioned (pivoted) in a retracted position below the horizontal engagement position, and the finger 72 is positioned in a pallet disengagement position. The pallet attitude changing device 42 is configured so that, in the retracted position, the arm 64 and the components thereof, namely the finger 72, the receiving portion 74, and the arm protrusion 86, do not interfere with the loading of the pallet 76. Meanwhile, the C-axis rotary table 36 (see FIG. 2) on the machining chamber 12 side (not shown) holds a second pallet 94 on which a machined (machined) workpiece W2 and a jig 96 are assembled.

[0035] 5 shows a state in which the arm 64 is rotated by the drive unit 62 to an engagement position where the arm 64 and the engagement side surface 76e of the pallet 76 face each other, and is positioned relative to the pallet 76. In this state, the arm protrusion 86 and the second pallet receiving surface 74b of the receiving unit 74 may be configured not to contact the pallet 76, or may be configured to contact the pallet 76. When not contacting the pallet 76, the pallet 76 is held on the rail 90. When contacting the pallet 76, the arm protrusion 86 contacts the upper surface of the inner wall of the pallet groove 88, and the second pallet receiving surface 74b contacts the lower surface 76b of the pallet 76. As a result, the pallet 76 is separated from the rail 90 and held by the arm 64. In this case, because the arm protrusion 86 is inserted into the pallet groove 88, the pallet 76 can be prevented from unexpectedly moving outside the machine tool 10, even if an unexpected external force acts on the pallet 76.

[0036] 6 shows a state in which the finger 72 is actuated (indicated by the arrow in the drawing) from the pallet disengagement position to the pallet engagement position, thereby engaging the finger 72 with the pin 78. Here, the finger 72 and the pin 78 are sized so that a gap (play) is created between the finger 72 and the pin 78 to the extent that the pin 78 does not fall out.

[0037] 7 shows the state in which the drive unit 62 rotates the arm 64 to an upright position, changing the orientation of the pallet 76 to an upright position. During the orientation change, the finger 72 and the pin 78 engage, restricting the movement of the pallet 76 alone in the rotational direction (direction R1). Furthermore, the second pallet support surface 74b abuts against the underside 76b of the pallet 76, and the first pallet support surface 74a abuts against the abutment side surface 76d of the pallet 76, supporting the weight of the pallet 76 and restricting movement in the direction of gravity. As a result, the arm 64 can change the orientation of the pallet 76 from a horizontal position to an upright position while stably holding the pallet 76.

[0038] 8 shows the APC arm 50 of the pallet exchange device 44 raised, with the pallet 76 held by the first pallet holder 82. Specifically, by raising the APC arm 50, the holding member 76f fits into the recessed portion of the first pallet holder 82, and the upper surfaces of the columnar members at both ends of the first pallet holder 82 abut against the abutment side surface 76d of the pallet 76. This allows the APC arm 50 to hold the pallet 76. At this time, the fingers 72 merely restrict the movement of the pins 78 in the rotational direction (direction R1) of the pallet 76 alone, so the APC arm 50 can lift the pallet 76 without interfering with the arm 64.

[0039] 9 shows a state in which the APC arm 50 holds the pallet 76 and the fingers 72 are moved from the pallet engagement position to the pallet disengagement position. As indicated by the arrow in the figure, by moving the fingers 72 from the pallet engagement position to the pallet disengagement position, only the APC arm 50 holds the pallet 76. At this time, the second pallet 94 on the processing chamber 12 side (not shown) is also removed from the C-axis rotary table 36. As a result, both the pallet 76 on the setup chamber 14 side and the second pallet 94 on the processing chamber 12 side (see FIG. 11) are held by the APC arm 50 alone.

[0040] 10 shows the arm 64, with the fingers 72 moved to the pallet disengagement position, rotated to the standby position by the drive unit 62. The pallet position changing device 42 can position (rotate) the arm 64 to a standby position between the upright position (upright state) and the engaged position (horizontal state). This prevents interference between the APC arm 50 and the rotating door 46 and the pallet position changing device 42 or other components within the machine tool 10 when the APC arm 50 and the rotating door 46 are rotated to exchange the pallet 76 in the setup chamber 14 with the second pallet 94 in the machining chamber 12. Furthermore, because the arm 64 can be positioned to the standby position without returning to the engaged position, the time required to rotate the arm 64 can be minimized, thereby shortening the time required to change the position and replace the pallet 76.

[0041] 11 shows a state in which the pallet 76 (see FIG. 10) on the setup chamber 14 side and the second pallet 94 on the machining chamber 12 side have been swapped (exchanged) by rotating the APC arm 50. By rotating the APC arm 50 holding the pallet 76 and the second pallet 94 180 degrees, the pallet 76 on which the unmachined workpiece W1 has been mounted can be moved to the machining chamber 12 side and delivered to the C-axis rotary table 36, and the second pallet 94 on which the machined workpiece W2 has been mounted can be moved to the setup chamber 14 side.

[0042] FIG. 12 shows the arm 64 rotated to an upright position by the drive unit 62, positioning the finger 72 for engagement with the upright second pallet 94. FIG. 13 shows the finger 72 moved from the pallet disengagement position to the pallet engagement position (indicated by the arrow in the figure) and engaged with the pin 78. This allows the arm 64 to hold the second pallet 94, which has moved toward the setup chamber 14. If the pallet disengagement position is configured to be closer to the arm base end 66 than the pallet engagement position and the arm protrusion 86 and pallet groove 88 are not present, the finger 72 would move from the pallet disengagement position to the pallet engagement position against gravity. Therefore, if chips or other debris interfere with the finger 72 and pin 78, the pallet would be lifted, potentially causing it to fall off. In this embodiment, the pallet engagement position is configured to be closer to the arm base end 66 than the pallet disengagement position. In other words, the finger 72 moves from the pallet disengagement position to the pallet engagement position along the force of gravity, so even if the finger 72 and the pin 78 interfere with each other, there is at least no risk of the pallet 76 falling off, and so the finger 72 can safely engage with the pin 78 (pallet 94).

[0043] 14 shows the APC arm 50 being lowered to release the second pallet 94 from the second pallet holder 84 of the APC arm 50. As indicated by the arrow in the figure, lowering the APC arm 50 causes the second pallet holder 84 to separate from the second pallet 94. As a result, the second pallet 94 is no longer held by the second pallet holder 84, and the first pallet receiving surface 74a of the receiving portion 74 abuts against the abutment side surface 94d of the second pallet 94, supporting the second pallet 94. In this manner, the second pallet 94 transferred to the pallet position changing device 42 is supported by the fingers 72 and the receiving portion 74. Meanwhile, the C-axis rotary table 36 (see FIG. 2) on the machining chamber 12 side (not shown) holds the pallet 76 to which the unmachined workpiece W1 and the jig 96 are attached.

[0044] FIG. 15 shows a state in which the drive unit 62 rotates the arm 64 to the engagement position, thereby moving the second pallet 94 to a horizontal position (setup position). FIG. 16 also shows a state in which the finger 72 is actuated from the pallet engagement position to the pallet disengagement position (indicated by the arrow in the figure), thereby disengaging the finger 72 from the pin 78. In this state, the arm protrusion 86 and the second pallet receiving surface 74b of the receiving portion 74 may be configured not to contact the second pallet 94, or may be configured to contact the second pallet 94. When not contacting the second pallet 94, the second pallet 94 is held on the rail 90. When contacting the second pallet 94, the arm protrusion 86 contacts the upper surface of the inner wall of the pallet groove 88, and the second pallet receiving surface 74b contacts the lower surface 94b of the second pallet 94. As a result, the second pallet 94 is released from the rail 90 and held by the arm 64.

[0045] Figure 17 shows a state in which the drive unit 62 has rotated the arm 64 and positioned it at the retracted position. As a result, the second pallet 94 is transferred from the arm 64 to the rail 90, and is ready to be transported outside the machine tool 10. Figure 18 shows a state in which the second pallet 94 is being transported outside the machine tool 10. In this way, the pallet 76 on which the unmachined workpiece W1 has been mounted and the second pallet 94 on which the machined workpiece W2 has been mounted can be exchanged after changing their positions between a horizontal position and an upright position.

[0046] FIG. 19 shows a side view of the medium supply unit 80 connected to the second pallet 94 in a horizontal position (setup position). In the pallet position change device 42 according to this embodiment, the arm 64 is configured to hold the engagement sides 76e, 94e of the pallet 76 (see FIG. 2) and the second pallet 94, and the arm 64 does not interfere with the undersides 76b, 94b of the pallet 76 and the second pallet 94. This allows space to be secured below the setup position, allowing the medium supply unit 80 to be positioned therein. The medium supply unit 80 can then hold and couple to the pallet 76 and the second pallet 94 that have been transported to the setup position. The medium supply unit 80 is equipped with a clamping mechanism (not shown) that clamps the pallet 76 and the second pallet 94. Furthermore, the medium supply unit 80 can be connected to couplers 100 (see FIG. 20A) located on the undersides 76b, 94b of the pallet 76 and the second pallet 94, allowing for the supply of hydraulic or pneumatic media from the connected flow paths. This makes it possible to supply hydraulic pressure, etc., to the pallet 76 and the second pallet 94 for operating the clampers that hold the workpieces W1, W2 on the jig 96. When the supply of the medium is completed, the medium supply unit 80 is configured to release the clamp and connection of the pallet 76 and the second pallet 94, and further, the pallet position changing device 42 is configured so that the arm 64 rotates to the engagement position and the finger 72 operates to the pallet engagement position to hold the pallet 76 and the second pallet 94. At this time, the jig 96 on the pallet 76 and the second pallet 94 is equipped with a pressure maintaining unit (not shown), such as an accumulator, and is configured to maintain pressure within the jig 96 even when the engagement between the pallet 76 and the second pallet 94 and the medium supply unit 80 is released.

[0047] Furthermore, the medium supply unit 80 disposed within the setup chamber 14 is configured to be movable up and down. Therefore, when the arm 64 changes the position of the pallet 76 and the second pallet 94, interference between the lower surfaces 76b, 94b of the pallet 76 and the second pallet 94 and the clamping mechanism (not shown) and the coupler mechanism (coupler 100 and coupler attachment portion 102) disposed on the upper surface of the medium supply unit 80 can be prevented. A specific example will be described with reference to FIGS. 20A to 20D . As shown in FIG. 20A , when the second pallet 94 is held on the rail 90, the medium supply unit 80 can be positioned at a sufficient distance below the rail 90. This prevents interference between the coupler 100 and the medium supply unit 80. Next, as shown in FIG. 20B , the held medium supply unit 80 rises (indicated by the arrow in the figure), clamping the second pallet 94 and connecting the coupler attachment portion 102 on the medium supply unit 80 side to the coupler 100 on the second pallet 94 side. This allows media including oil, air, and cutting fluid to be supplied from the media supply unit 80. Once the supply of media is complete, the media supply unit 80 releases the clamp and coupler mechanism of the second pallet 94 and descends (indicated by the arrow in the figure), as shown in FIG. 20C. Once the descent of the media supply unit 80 is complete, the arm 64 rotates to the engaged position and holds the second pallet 94, as shown in FIG. 20D. In this way, the media supply unit 80 can efficiently supply media while preventing interference with the pallet 76 and the second pallet 94.

[0048] The pallet position changing device 42 according to this embodiment includes a pair of arms 64 rotatably attached to the drive unit 62, extending parallel to the engagement sides 76e, 94e when facing the engagement sides 76e, 94e, and holding the pallets 76, 94; and fingers 72 slidably disposed on the arms 64 and moving from a pallet disengagement position to a pallet engagement position to engage with the pallets 76, 94. Thus, the pallet position changing device 42 can change the position of the pallets 76, 94, including between a horizontal position and an upright position, by rotating the arms 64 holding the pallets 76, 94 using the drive unit 62. Furthermore, the pair of arms 64 can stably hold the pallets 76, 94 by engaging with two sides of the pallets 76, 94, i.e., the engagement sides 76e, 94e, via the fingers 72. Such arms 64 simplify the structure of the pallet position changing device 42 while ensuring the effectiveness of the arm 64 behavior. Furthermore, the pallet position changing device 42 includes a receiving portion 74 disposed on the base 60 side of the arm 64 and having a first pallet receiving surface 74a facing abutment side surfaces 76d, 94d located between the two engagement side surfaces 76e, 94e. Therefore, when the position of the pallet 76, 94 is changed by rotating the arm 64 and the upper surfaces 76a, 94a are tilted relative to the horizontal plane, the abutment side surfaces 76d, 94d of the pallet 76, 94 can be brought into contact with the first pallet receiving surface 74a, and the pallet 76, 94 can be stably held, even as the position of the pallet 76, 94 changes, including between a horizontal position and an upright position. As described above, the pallet position changing device 42 can change the position of the pallet 76, 94 while holding it using a simple structure, enabling stable pallet transport.

[0049] Furthermore, according to the pallet attitude changing device 42 of this embodiment, cylindrical pins 78 are formed on the two engagement side surfaces 76e, 94e of the pallets 76, 94, extending toward the arm 64, i.e., outward in the X-axis direction. Therefore, the arm 64 can stably hold the pallet 76 by engaging the fingers 72 with the pins 78. Furthermore, because the surface of the pins 78 only makes linear contact with the grooves 72d of the fingers 72, it is possible to prevent chips generated during machining from getting caught.

[0050] Furthermore, according to the pallet position changing device 42 of this embodiment, the depth direction of the groove 72d of the finger 72 coincides with the extension direction of the pin 78, and is sized so that a gap (play) is created between the finger 72 and the pin 78 to the extent that the pin 78 will not fall out. Therefore, when the arm 64 is rotated to the upright position to change the position of the pallet 76 to an upright state, the finger 72 and the pin 78 engage, making it possible to restrict movement of the pallet 76 alone in the rotational direction (direction R1).

[0051] Furthermore, according to the pallet attitude changing device 42 of this embodiment, the slide portion 70 and finger 72 of the arm engaging portion 68 are configured to move between the pallet engaging position and the pallet disengaging position along the longitudinal direction of the arm 64. This makes it possible to save space in the width direction of the arm 64, allowing the arm 64 to be configured compactly.

[0052] Furthermore, with the pallet attitude changing device 42 according to this embodiment, the slide section 70 and the finger 72 can be moved in the same direction between the pallet engagement position and the pallet disengagement position, and the pallet engagement position is configured to be closer to the arm base end 66 than the pallet disengagement position. This allows the finger 72 and the pin 78 to be safely engaged with each other.

[0053] Furthermore, with the pallet orientation changing device 42 according to this embodiment, the arm 64 can be positioned at a standby position between the upright position (upright state) and the engaged position (horizontal state). This prevents interference between the pallet orientation changing device 42 and other components within the machine tool 10 when the APC arm 50 and the pivoting door 46 are pivoted to interchange the pallet 76 on the setup chamber 14 side with the second pallet 94 on the machining chamber 12 side. Furthermore, because the arm 64 can be positioned at the standby position without returning to the engaged position, the time required to rotate the arm 64 can be minimized, thereby shortening the time required to change the orientation and replace the pallets 76, 94.

[0054] Furthermore, according to the pallet position changing device 42 of this embodiment, the receiving portion 74 has a planar first pallet receiving surface 74a extending perpendicular to the longitudinal direction of the arm 64, as well as a planar second pallet receiving surface 74b extending along the longitudinal direction of the arm 64. Therefore, when the arm 64 is rotated to the upright position and the position of the pallet 76, 94 is changed to an upright state, the second pallet receiving surface 74b abuts against the underside 76b of the pallet 76 to support the weight of the pallet 76, 94 and restrict movement in the direction of gravity. This allows the arm 64 to change the position of the pallet 76, 94 from a horizontal state to an upright state while stably holding the pallet 76, 94.

[0055] Furthermore, according to the pallet attitude changing device 42 of this embodiment, an arm protrusion 86 extending toward the engagement side surface 76e is formed on the widthwise inner side of the arm engagement portion 68 opposite the engagement side surface 76e. Furthermore, a pallet groove 88 recessed inward of the pallet 76 is formed on the engagement side surface 76e, allowing the arm protrusion 86 to be inserted. This allows the arm 64 to stably hold the pallets 76, 94. Furthermore, when the arm 64 is positioned in a horizontal position, even if an unexpected external force acts on the pallet 76, it is possible to prevent the pallet 76 from unexpectedly moving outside the machine tool 10.

[0056] Furthermore, with the pallet position changing device 42 according to this embodiment, the arm 64 is configured to be able to rotate and position (be able to stop) not only between the upright state and the horizontal state, but also from the upright position in the upright state to a retracted position beyond the engagement position in the horizontal state. Therefore, the arm 64 and the components of the arm 64, such as the finger 72, the receiving portion 74, and the arm protrusion 86, can be prevented from interfering with the pallet 76 being carried in, making it easier to carry in the pallet 76.

[0057] Furthermore, according to the machine tool 10 of this embodiment, in addition to the pallet position changing device 42 described above, the machine tool 10 is equipped with a pallet exchange device 44 having an APC arm 50 having, at both ends, a first pallet holding part 82 for receiving and delivering an upright pallet 76 and a second pallet holding part 84 for receiving and delivering an upright second pallet 94. Therefore, the pallets 76, 94 whose position has been changed by the pallet position changing device 42 can be stably transported to the spindle 26 side. As a result, the machine tool equipped with the pallet position changing device 42 and the pallet exchange device 44 can change the position of the pallets 76, 94 while holding them using a simple structure, enabling stable pallet transport.

[0058] Furthermore, with the machine tool 10 according to this embodiment, when the pallets 76, 94 are positioned horizontally (in the setup position), a medium supply unit 80 can be disposed below the pallets 76, 94 and configured to be connectable to the undersides 76b, 94b of the pallets 76, 94. The arm 64 is configured to hold the engagement sides 76e, 94e of the pallets 76, 94, and therefore does not interfere with the undersides of the pallets 76, 94. Therefore, the medium supply unit 80 can be disposed there, and media including oil, air, and cutting fluid can be supplied to the pallets 76, 94. This saves space and allows the machine tool 10 to be configured compactly.

[0059] As described above, the pallet attitude changing device 42 of the machine tool 10 according to this embodiment uses a simple structure to change the attitude of the pallets 76, 94 while holding them, thereby enabling stable pallet transport.

[0060] (Modification) Here, the arm 64 has been described as having two slide portions 70 and fingers 72 at both longitudinal ends of the arm engagement portion 68, and the receiving portion 74 has a planar first pallet receiving surface 74a extending perpendicular to the arm 64 and a planar second pallet receiving surface 74b extending along the longitudinal direction of the arm 64. However, this is not limited to this. As shown in FIG. 21 , depending on the application, a configuration may be possible in which one finger 72 is provided at the longitudinal tip of the arm engagement portion 68, and the receiving portion 74 has only the first pallet receiving surface 74a. Even with this configuration, the pallets 76, 94 can be stably held when the position of the arm 64 is changed. Furthermore, the number of parts can be reduced, thereby reducing the number of work steps and costs during the manufacture of the machine tool 10.

[0061] Although the embodiment of the pallet attitude changing device 42 of the machine tool 10 has been described above, the present invention is not limited to the above embodiment. In addition to the above, it is believed that a person skilled in the art would understand that various modifications of the above embodiment are possible.

[0062] 10 Machine tool 26 Spindle 28 Tool 36 C-axis rotary table (table) 42 Pallet attitude changing device 44 Pallet exchange device 46 Swivel door 48 Swivel door holding section 50 APC arm (swivel arm) 52 Chip cover 56 APC arm drive mechanism (swivel drive section) 60 Base 62 Drive section 64 Arm 66 Arm base end section 72 Finger 72a Upper surface side regulating section 72b Lower surface side regulating section 72c Center section 72d Groove section 74 Receiving section 74a First pallet receiving surface 74b Second pallet receiving surface 76 Pallet (first pallet) 76a Upper surface 76b Lower surface 76d Contact side surface 76e Engagement side surface 78 Pin 80 Medium supply section 82 First pallet holding section 84 Second pallet holding portion 86 Arm protrusion 88 Pallet groove 94 Second pallet (pallet) 94b Lower surface 94d Contact side surface 94e Engagement side surface 96 Jig B B-axis rotation direction C C-axis rotation direction RA1 Rotation center axis of drive unit R1 Rotation direction of drive unit RA2 Swing center axis of APC arm drive mechanism R2 Swing direction of APC arm drive mechanism W1 Workpiece W2 Workpiece W3 Workpiece

Claims

1. A pallet position changing device for changing the position of a pallet having an upper surface for assembling workpieces and jigs, a lower surface, two engaging side surfaces in contact with the upper and lower surfaces, and an abutting side surface located between the two engaging side surfaces, between a horizontal state in which the upper surface of the pallet is moved toward a horizontal plane, and an upright state in which the upper surface of the pallet is moved toward a vertical plane, the pallet position changing device comprising: a base; a drive unit attached to the base and configured to be able to rotate the pallet around a central axis of rotation in order to change the position; a pair of arms rotatably attached to the drive unit, extending so as to be parallel to the engaging side surfaces when facing the engaging side surfaces, and holding the pallet; a receiving part arranged on the arm on the side of the base, and having a first pallet receiving surface facing the abutting side surfaces; and a finger slidably arranged on the arm, which moves from a pallet disengagement position to a pallet engagement position to engage the pallet.

2. A pallet position changing device according to claim 1, wherein the two engaging sides each have at least one pin extending from the engaging side to the outside of the pallet and engaging with the finger.

3. A pallet posture changing device as described in claim 2, wherein the finger has a central portion facing the engaging side surface, an upper surface regulating portion formed above the central portion, and a lower surface regulating portion formed below the central portion, and a concave groove portion facing the pallet is formed by the central portion, the upper surface regulating portion, and the lower surface regulating portion, and the depth direction of the groove portion coincides with the extension direction of the pin.

4. A pallet attitude changing device according to claim 1, wherein said finger moves along the longitudinal direction of said arm between said pallet engaging position and said pallet disengaging position.

5. A pallet posture changing device as described in claim 4, wherein the pallet engagement position of the finger is located closer to the arm base end attached to the base of the arm than the pallet disengagement position in the longitudinal direction of the arm.

6. A pallet attitude changing device according to claim 1, wherein said finger moves between said pallet engaging position and said pallet disengaging position along the direction in which said arm and said pallet face each other.

7. A pallet attitude changing device as set forth in claim 1, wherein said drive unit is configured to be able to position said arm at a standby position between an engagement position in said horizontal state and an upright position in said upright state.

8. A pallet attitude changing device according to claim 1, wherein the receiving portion has a second pallet receiving surface formed so as to be able to abut against the lower surface of the pallet.

9. A pallet posture changing device as described in claim 1, wherein the pallet has a pallet groove formed so as to recess from the engagement side surface toward the inside of the pallet, and the arm has an arm protrusion that can be inserted into the inside of the pallet groove.

10. A pallet attitude changing device as described in claim 1, wherein the drive unit is configured to rotate and position the arm from an upright position in the upright state to a retracted position beyond the engagement position in the horizontal state.

11. A machine tool comprising: a spindle on which a tool is attached; a table on which the pallet having the workpiece assembled thereon can be attached in the upright state; a pallet position changing device as set forth in any one of claims 1 to 10; and a pallet exchange device having, on the side of the pallet position changing device and the side of the spindle, a rotating arm having, at both ends, a first pallet holding portion for receiving and delivering the first pallet in the upright state and a second pallet holding portion for receiving and delivering the second pallet in the upright state, and a rotating drive unit for rotating the rotating arm around a rotating axis parallel to the vertical direction.

12. A machine tool as described in claim 11, further comprising a media supply unit configured to be connectable with the underside of the pallet when the pallet is positioned in the horizontal state by the pallet attitude changing device, and supplying a medium including oil, air, and cutting fluid to the pallet and any of the workpieces and / or jigs mounted on the pallet.

Images