JP5125420B2 - Workpiece attachment / detachment device - Google Patents

Description

  The present invention relates to a workpiece attaching / detaching device provided in a machine tool and capable of exchanging a pallet with a work table.

In the pallet exchanging apparatus for exchanging the pallet 26 between the work table 10 and the loading position by the swivel arm 32, the rotary table 41 can be rotated to the loading position in order to make it easy to attach and detach the workpiece at the loading position. A workpiece attaching / detaching device provided with an engaging pin 50 for positioning the rotary table 41 at a predetermined angular position is described in Patent Document 1.
Japanese Patent Laid-Open No. 62-34748 (first page and FIG. 1)

  However, in the workpiece attaching / detaching apparatus described in Patent Document 1, since the rotary table is manually rotated, when the workpiece is heavy, for example, when the workpiece weight exceeds 3000 kg, it is too heavy and manually operated. However, there is a problem that even if it can rotate, the inertial force works and it cannot be stopped at a predetermined angular position. In addition, when a drive device such as an electric motor or a hydraulic motor is provided, heavy objects can rotate, but there is a problem that auxiliary equipment such as an encoder and a brake are required in addition to the electric motor and hydraulic motor, which increases the cost. There has been a demand for a workpiece attaching / detaching device including a rotary table that is inexpensive and capable of rotating heavy objects.

  The present invention has been made in order to solve the above-described conventional problems, and includes a rotary table that is simple in structure and inexpensive, and that can perform indexing rotation at a predetermined angular position even if the workpiece is heavy. It is intended to provide a workpiece attachment / detachment device.

In order to solve the above-mentioned problems, the invention according to claim 1 is directed to a spindle head that rotatably supports a spindle on which a tool is detachably mounted, and a work table on which a pallet to which a workpiece is detachably attached is carried in and out. When the relative movement device for relatively moving the said and the spindle head work table, a workpiece attachment apparatus for attaching and detaching the workpiece to the pallet, the Engineering crops removable and the work table which has been moved to the pallet exchanging position A workpiece attachment / detachment device used in a machine tool including a pallet loading / unloading device for loading / unloading the pallet to / from the device, the unit base having a base mounted thereon, and rotatable to the base A supported rotary table and a gear mounted coaxially on the base so as to be rotatable about a rotation axis fixed to the rotary table and extending in the vertical direction. A rotating shaft, a fluid pressure cylinder fixed horizontally to the base, and first and second outer pistons fitted to the fluid pressure cylinder so as to be slidable by a predetermined stroke and connected to each other by a connecting rod; The fluid pressure cylinder is sealed and fitted at both ends, and is sealed and fitted to the connecting rod, and can slide between the first and second outer pistons by twice the predetermined stroke. And an intermediate piston having a central portion engraved with a rack meshed with the gear via a pinion, between the both ends of the fluid pressure cylinder and the outer end surfaces of the first and second outer pistons. Fluid is supplied to and discharged from the first and second cylinder chambers divided into the first and second cylinder chambers, and the third and fourth cylinder chambers defined between the inner end surfaces of the first and second outer pistons and the intermediate piston. By It is characterized in that rotating the serial rotary table by a predetermined angle.

  The invention according to claim 2 is the workpiece attaching / detaching device according to claim 1, wherein the base, the rotary table, the rotary shaft, the fluid pressure cylinder, the first and second outer pistons, The intermediate piston constitutes a workpiece attaching / detaching unit, and the workpiece attaching / detaching unit is inserted from above into a mounting hole formed in the unit base, and is detachably fixed to the unit base. It is what.

  According to the invention concerning Claim 1 comprised as mentioned above, a pallet is replaced | exchanged between the work tables of a machine tool, and the workpiece attachment or detachment apparatus for attaching or detaching the workpiece on the pallet carried out from the work table. The first and second outer pistons connected to the fluid pressure cylinder by the connecting rod are slidably fitted with a predetermined stroke S, and the intermediate piston in which the rack is engraved is between the first and second outer pistons. Thus, a gear provided on a rotary shaft fixed to the rotary table 50 is slidably fitted by a predetermined stroke S, and is rotationally connected via a pinion and a gear meshing with the rack. As a result, the rotary table of the workpiece attaching / detaching device is reliably rotated by a predetermined pressure even when a heavy workpiece is placed on the pallet by a fluid pressure cylinder device having an outer piston and an intermediate piston with a simple and inexpensive configuration. It can be rotated by an angle and stopped at a predetermined angular position.

  According to the invention of claim 2, in the workpiece attaching / detaching device according to claim 1, the integrated workpiece attaching / detaching unit has a simple configuration in which the fluid pressure cylinder fits the outer piston and the intermediate piston. Since the length of the lower portion in the radial direction is shortened, the lower portion is inserted into the mounting hole formed in the unit base from above, and is detachably fixed to the unit base. Therefore, when it is desired to change the turning method of the rotary table, for example, in the case of a turning method using a fluid pressure cylinder device as in the present application, in the case of an automatic turning method using a servo motor used for FMS or the like, or when the workpiece is lightweight. In the case of the applicable manual turning method, each workpiece attaching / detaching unit can be easily attached / detached from the mounting hole drilled in the unit base, so that a workpiece attaching / detaching unit selected depending on the case can be attached. This can greatly reduce the manufacturing cost when changing the turning method of the rotary table.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. 11 is a bed of the machining center 10, and the bed 11 includes a column sliding portion 12 extending in the horizontal X-axis direction and a table sliding portion 13 extending at right angles to the X-axis and extending in the horizontal Z-axis direction. It is configured integrally and is placed in a pit dug in the floor surface FL. The table sliding portion 13 is formed integrally with the column sliding portion 12 at the rear end so as to intersect with the T-shape.

  A column 14 is placed on the column sliding portion 12 of the bed 11 so as to be movable in the X-axis direction. Guide rails 15 and 16 are fixed to the upper surface of the column sliding portion 12 in parallel to each other in the horizontal X-axis direction, and the column 14 is guided by the guide rails 15 and 16 to move on the column sliding portion 12 in the X-axis direction. Moving. In the bed 11, a ball screw shaft 17 extending in the X-axis direction is rotatably supported by bearings 18, 19 between the guide rails 15, 16, and the back end penetrates the bearing 19. The servo motor 20 is rotationally connected. A nut fixed to the lower surface of the column 14 is screwed with the ball screw shaft 17, and the ball screw shaft 17 is rotated by the X-axis servomotor 20, whereby the column 14 is moved in the X-axis direction.

  A headstock 21 is mounted on the column 14 so as to be slidable in the Y-axis direction perpendicular to the horizontal plane, and is moved up and down by a Y-axis servomotor 22 via a ball screw 23. A spindle 24 on which a tool T is detachably mounted is rotatably supported on the spindle base 21 and is driven to rotate by a spindle servomotor 25.

  A work table 26 is placed on the table sliding portion 13 of the bed 11 so as to be movable in the Z-axis direction. Guide rails 27 and 28 are fixed to the upper surface of the table sliding portion 13 in parallel with each other in the horizontal Z-axis direction, and the work table 26 is guided by the guide rails 27 and 28 to move on the table sliding portion 13 in the Z-axis direction. Move to. Ball screw shafts 29, 30 extending in the Z-axis direction are supported on the bed 11 by bearings 31, 32 inside the guide rails 27, 28 so that both ends can be rotated. In FIG. 54 and 55 are rotatably connected to the Z-axis servomotors 33 and 34. The nut fixed to the lower surface of the work table 26 is screwed with the ball screw shafts 29 and 30, and the ball screw shafts 29 and 30 are rotated synchronously by the Z axis servo motors 33 and 34, whereby the work table 26 is moved to the Z axis. Moved in the direction.

  An index table 35 is mounted on the work table 26 so as to be indexable and rotatable about an axis parallel to the Y axis, and is indexed and rotated via a servo motor and a speed reduction mechanism (not shown). . On the index table 35, a pallet clamping device (not shown) for positioning and clamping the loaded pallet 36 is provided. A workpiece W to be processed is detachably attached to the pallet 36.

  The tool changer 39 is disposed at the back end of the column sliding portion 12. The tool changer 39 includes a tool magazine 40 that stores a plurality of tools T, and a tool change mechanism 41 that changes the tool T between the tool magazine 40 and the main shaft 24. The tool magazine 40 is provided along the back end of the column sliding portion 12 in the Z-axis direction, and the tool changing mechanism 41 is provided in front of the back end of the column sliding portion 12.

  When the processing of the workpiece W is completed, the work table 26 is moved to the pallet exchange position 46 provided at the front end portion of the table sliding portion 13. First and second pallet loading / unloading for loading / unloading the pallet 36 between the indexing table 35 on the work table 26 positioned at the pallet replacement position 46 and the first and second workpiece attaching / detaching devices 44 and 45. The devices 47 and 48 are arranged in a V shape so as to incline in an acute angle direction on both sides with respect to the Z axis.

  Since the first and second workpiece attaching / detaching devices 44 and 45 have the same configuration, the first workpiece attaching / detaching device 44 will be described. As shown in FIG. 3, a unit base 79 provided in the machining center 10 is placed on a pit dug in the floor, and a base 49 is detachably fixed to the unit base 79 with bolts 80. A rotary table 50 is rotatably supported on the top. A rotary shaft 51 extending downward is fixed to the rotary table 50, and the rotary shaft 51 is supported by a base 49 so as to be rotatable around a rotary axis extending in the vertical direction by a bearing 53. A gear 52 is fixed to the rotating shaft 51 below the bearing 53.

  A pinion shaft 55 with a pinion 54 formed integrally with the base 49 is supported by a bearing 56 in parallel with the rotation shaft 51. A large gear 57 that meshes with the gear 52 is supported on the base 49 by a bearing 58 coaxially with the pinion shaft 55, and the large gear 57 is spline-fitted to the pinion shaft 55.

  As shown in FIG. 4, a hydraulic cylinder 60 is fixed to the base 49 in the horizontal direction. First and second outer pistons 62 and 63 connected to each other by a connecting rod 61 are fluidly fitted to the hydraulic cylinder 60 so as to be slidable by a predetermined stroke S. Here, the predetermined stroke S can be adjusted by adjusting screws 78 provided at both ends of the hydraulic cylinder 60. An intermediate piston 64 is fitted to the hydraulic cylinder 60 so as to be slidable between the first and second outer pistons 62 and 63 by twice the predetermined stroke S. The intermediate piston 64 is liquid-tightly sealed and fitted to the hydraulic cylinder 60 at both ends 65 and 66, and a rack 67 that meshes with the pinion 54 is engraved between the both ends 65 and 66. A central hole 68 is formed in the intermediate piston 64, and the connecting rod 61 is liquid-tightly sealed through the central hole 68.

  Thus, the first and second cylinder chambers 69 and 70 are partitioned between the both ends of the hydraulic cylinder 60 and the outer end surfaces of the first and second outer pistons 62 and 63, and the first and second outer pistons 62 are separated. , 63, and third and fourth cylinder chambers 71, 72 are defined between the inner end surfaces of the intermediate piston 64. Accordingly, when the solenoids of the first and second switching valves 73 and 74 are de-energized and the pressure oil is supplied to the first and third cylinder chambers 69 and 71, the first and second outer pistons 62 and 63 become hydraulic cylinders. The intermediate piston 64 is positioned at the retracted end with respect to the first and second outer pistons 62, 63. Thereby, the intermediate piston 64 is located at the original position with respect to the hydraulic cylinder 60, and the rotary table 50 is located at the original position via the rack 67, the pinion 54, the large gear 57 and the gear 52. When the first switching valve 73 is switched by the energization of the solenoid, the first and second outer pistons 62 and 63 move at a predetermined stroke S and are positioned at the forward end. At this time, the intermediate piston 64 is located at the retracted end with respect to the first and second outer pistons 62 and 63. As a result, the intermediate piston 64 and the rack 67 are moved by a predetermined stroke S, and the rotary table 50 is rotated 90 ° from the original position by setting the gear ratios of the gear 52 and the large gear 57 appropriately (FIG. 5). (See (a)).

  Next, when the solenoid of the first switching valve 73 is de-energized and the solenoid of the second switching valve 74 is energized, pressure oil is supplied to the first cylinder chamber 69 and the fourth cylinder chamber 72, and the first and second cylinders 72 and 72 are energized. The two outer pistons 62 and 63 are retracted by the predetermined stroke S, and the intermediate piston 64 is advanced by twice the predetermined stroke S with respect to the first and second outer pistons 62 and 63. As a result, the intermediate piston and the rack 67 are moved forward from the original position by twice the predetermined stroke S, and the rotary table 50 is rotated 180 ° from the original position (see FIG. 5B). When the solenoids of the first switching valve 73 and the second switching valve 74 are energized, the pressure oil is supplied to the second cylinder chamber 70 and the fourth cylinder chamber 72, and the first and second outer pistons 62, 63 are set in a predetermined manner. The stroke S is advanced, and the intermediate piston 64 is positioned at the forward end with respect to the first and second outer pistons 62 and 63. As a result, the intermediate piston and the rack 67 are advanced from the original position by three times the predetermined stroke S, and the rotary table 50 is rotated 270 ° from the original position (see FIG. 5C).

  A through hole 75 is formed in the rotary table 50 and the rotary shaft 51 so as to penetrate the rotational axis, and a holding pin 76 is slidably fitted in the through hole 75. A piston rod of a cylinder device 77 fixed to the base 49 is connected to the lower end of the holding pin 76. When the pallet 36 is carried onto the rotary table 50, the holding pin 76 is advanced by the cylinder device 77 to engage with the holding hole provided in the pallet 36, and the pallet 36 is locked onto the rotary table 50.

  In this way, the workpiece attaching / detaching unit 83 includes an intermediate piston in which the rotary table 50 rotatably supported on the base 49, the hydraulic cylinder 60, the first and second outer pistons 62 and 63, and the rack 67 are engraved. A hydraulic cylinder device 82 composed of 64 and the like, and a gear train 84 composed of a pinion 54, a large gear 57, a gear 52 and the like meshing with the rack 67 are assembled to the base 49.

  The workpiece attaching / detaching unit 83 is inserted from above into a mounting hole 81 drilled in a unit base 79 provided in the machining center 10 and is detachably fixed to the unit base 79 by bolts 80. At this time, the hydraulic cylinder device 82 is configured such that the outer pistons 62 and 63 and the intermediate piston 64 are fitted to the hydraulic cylinder 60 and the radial length of the lower portion of the workpiece attaching / detaching unit 83 is shortened. It can be inserted into the mounting hole 81 and fixed to the unit base 79. Therefore, when the turning method of the rotary table is not based on hydraulic pressure as in the present application, it is changed to an automatic turning method using a servo motor used for FMS or the like, or a manual turning method that can be applied when the workpiece is light. The workpiece attaching / detaching unit 83 is removed from the mounting hole 81, and instead of the automatic turning type workpiece attaching / detaching unit by the servo motor or the manual turning type workpiece attaching / detaching unit in the mounting hole 81 formed in the unit base 79. The rotary table turning method can be easily changed by being inserted from above and detachably fixed to the unit base 79 with bolts 80.

  When a start switch on an operation panel (not shown) is pressed to operate the machining center 10, NC data stored in the CNC device is sequentially read, the spindle 24 is rotated by the spindle servomotor 25, and the X axis, Y axis The column 14, the headstock 21 and the work table 26 are moved by the Z-axis servomotors 20, 22, 33 and 34, and the workpiece W is machined by the tool T.

  During such processing, in the tool magazine 40, the tool T to be used next is indexed to the replacement position, and is swung so as to be parallel to the Z axis by the swiveling mechanism and is waiting at the standby position. When the machining with the first tool T is completed, the rotation of the spindle 24 is stopped, and the column 14 and the spindle stock are moved to an exchange position where the spindle 24 is aligned with the tool exchange mechanism 41. The gripping devices provided at both ends of the exchange arm 49 of the tool exchange mechanism 41 grip the tool T mounted on the main shaft 24 and the tool T at the standby position of the tool magazine 40, and the tool clamping device built in the main shaft 24 is used as a tool. T is released, the exchange arm moves forward, retreats after turning 180 °, and the tool T to be used next is mounted on the main shaft 24. When the next tool is mounted on the spindle 24 and clamped by the clamping device, the column 14, the spindle stock 21, and the work table 26 are moved, and the workpiece W is processed by the next tool T.

  When such processing is repeated to complete processing on the workpiece W, the work table 26 is positioned at the pallet replacement position 46 by the Z-axis servomotors 33 and 34. The indexing table 35 is rotationally positioned so that the mounted pallet 36 faces the direction of the second workpiece attaching / detaching device 45 at the pallet changing position 46, and the pallet clamping device unclamps the pallet. The engaging portion of the second pallet loading / unloading device 48 is advanced to engage with the engaging portion of the pallet 36, and the engaging portion is retracted to place the pallet 36 at the original position of the second workpiece attaching / detaching device 45. It is carried out to the second attachment / detachment position 76. Between the pallet exchange position 46 and the second attachment / detachment position 76, a pair of conveying rails 52 are provided on the upper surface of which a plurality of rolling rollers are projected in alignment.

  When the pallet 36 is carried out onto the rotary table 50, the holding pin 76 is raised by the cylinder device 77 and the pallet 36 is locked onto the rotary table 50. In this state, the rotary table 50 is rotated to a desired angular position by switching the first and second switching valves 73 and 74, and necessary work and inspection are performed on the workpiece W. Thereafter, the workpiece W is moved to the pallet. 36 is removed.

  When the pallet 36 loaded with the processed workpiece W is unloaded, the indexing table 35 is rotationally positioned so that the pallet clamping device faces the direction of the first workpiece attaching / detaching device 44. During the processing of the previous workpiece W, the unprocessed workpiece W is attached at the first attachment / detachment position 75 of the first workpiece attachment / detachment device 44. At this time, the first and second switching valves 73 and 74 provided in the hydraulic cylinder device 82 are appropriately de-energized or energized to appropriately supply the fluid to the first or second cylinder chambers 69 and 70 and the third or fourth cylinder. The chambers 71 and 72 are fed and discharged, the rotary table 50 and the pallet placed thereon are rotated by a desired angle, and the unprocessed workpiece W is attached. The engaging portion of the first pallet loading / unloading device 47 engaged with the pallet 36 to which the unprocessed workpiece W is attached moves forward, and the pallet 36 is loaded onto the indexing table 35 from the first attachment / detachment position 75. And is clamped by a pallet clamping device. Also between the first attachment / detachment position 75 and the pallet replacement position 46, a pair of conveying rails 53 are provided on the upper surface.

  In this embodiment, as described above, the rotation angle position of the turntable 50 is set to 90 degrees, 180 degrees, and 270 degrees from the original position, but the strokes of the first and second outer pistons 62 and 63 and the intermediate piston 64, If the gear ratio between the gear 52 and the large gear 57 is appropriately changed as necessary, the desired rotational angle position of the rotary table can be obtained.

  In the above embodiment, the first and second pallet loading / unloading devices 47 and 48 for loading and unloading the pallet 36 between the first and second workpiece attaching / detaching devices 44 and 45 are provided on the Z axis. The first and second workpiece attaching / detaching devices 44 and 45 in the case where the first and second workpiece attaching / detaching devices 44 and 45 are arranged in a V-shape inclined at both sides in an acute angle direction have been described. A similar configuration may be used for the workpiece attaching / detaching device when exchanging with the workpiece.

  Further, in the above-described embodiment, the workpiece attaching / detaching device of the machining center has been described. However, the same workpiece attaching / detaching device can be used in other machine tools such as a dedicated machine tool.

The top view of the machining center provided with the workpiece attachment / detachment apparatus which concerns on embodiment of this invention. The side view of a machining center. Sectional drawing of a workpiece attachment / detachment apparatus. The figure which shows a hydraulic cylinder, an outer side piston, and an intermediate | middle piston. The figure which shows the position of the outer side piston and intermediate | middle piston in each rotation angle position of a turntable.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Machining center, 11 ... Bed, 12 ... Column sliding part, 13 ... Table sliding part, 14 ... Column, 20 ... X-axis servo motor, 21 ... Main shaft base, 22 ... Y-axis servo motor, 24 ... Main shaft, 25 ... Spindle servo motor, 26 ... Worktable,
33, 34 ... Z-axis servo motor, 35 ... Indexing table, 36 ... Pallet, 39 ... Tool changer, 44, 45 ... First and second workpiece attachment / detachment devices, 46 ... Pallet change position, 47, 48 ... First First and second pallet loading / unloading device 49: base, 50: rotating table, 51: rotating shaft, 52 ... gear, 54 ... pinion, 55 ... pinion shaft, 57 ... large gear, 60 ... hydraulic cylinder, 61 ... Connecting rods 62, 63 ... first and second outer pistons 64 ... intermediate pistons 65, 66 ... both ends, 67 ... racks, 68 ... center holes, 69, 70 ... first and second cylinder chambers 71, 72 ... 3rd and 4th cylinder chambers, 73 ... 1st switching valve, 74 ... 2nd switching valve, 78 ... Adjustment screw,
79 ... Unit base, 80 ... Bolt, 81 ... Mounting hole, 83 ... Workpiece attachment / detachment unit,
T ... Tool, W ... Workpiece.

Claims (2)

A spindle head that rotatably supports a spindle on which a tool is detachably mounted, a work table on which a pallet on which a workpiece is detachably mounted is loaded and unloaded, and a relative movement that relatively moves the spindle head and the work table. a device, and a workpiece attachment apparatus for attaching and detaching the workpiece to the pallet, and the pallet loading and unloading apparatus for loading and unloading the pallet between the work table which has been moved to the pallet exchanging position and the machining crop attachment apparatus A workpiece attaching / detaching device used in a machine tool comprising:
A unit base with a base;
A turntable rotatably supported on the base;
A rotary shaft fixed to the rotary table and supported by the base so as to be rotatable around a rotary axis extending in the vertical direction;
A fluid pressure cylinder fixed horizontally to the base;
First and second outer pistons slidably fitted to the fluid pressure cylinder for a predetermined stroke and connected to each other by a connecting rod;
The fluid pressure cylinder is sealed and fitted at both ends, and is sealed and fitted to the connecting rod, and can slide between the first and second outer pistons by twice the predetermined stroke. And an intermediate piston in which a rack meshed with the gear through a pinion is engraved at a central portion,
First and second cylinder chambers defined between both ends of the fluid pressure cylinder and outer end surfaces of the first and second outer pistons, and inner end surfaces of the first and second outer pistons and the intermediate A workpiece attaching / detaching apparatus, wherein the rotary table is rotated by a predetermined angle by supplying and discharging fluid to and from third and fourth cylinder chambers partitioned between the pistons. The workpiece attaching / detaching device according to claim 1,
The base;
The rotary table;
The rotating shaft;
The fluid pressure cylinder;
The first and second outer pistons;
A workpiece attaching / detaching unit is constituted by the intermediate piston,
The workpiece attachment / detachment apparatus, wherein the workpiece attachment / detachment unit is inserted into an attachment hole formed in the unit base from above and is detachably fixed to the unit base.

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