DE3418893A1 - Method and device for loading and unloading workpieces on a machine tool - Google Patents

Abstract

An automatic workpiece loading device uses two component grippers (32, 33), which are secured on the tool turret (24) of a lathe. The operation of the tool turret system is such that it causes the grippers (31, 32) to change components between a component stand-by position (31) and the machine shaft chuck (14) on the basis of an axial movement and a 180 DEG rotation of the grippers. <IMAGE>

Description

Case 8314F.::::; : ": *

CINCINNATI MILACRON INDUSTRIES, INC.

4701 Marburg Avenue, Cincinnati, Ohio 45209, U.S.A.

Method and device for loading and unloading workpieces on a machine tool.

The invention relates in general to lathes or lathes, wherein a plurality of turning tools, either inner diameter turning tools or outer diameter turning tools, on an adjustable one Rotary head or turret head are carried, the tools being selectively movable or adjustable to the work zone and by means of suitable slides, which are generally coordinate slide systems include, are brought into engagement with a workpiece.

The various automatic parts loading systems currently in use use a parts loader which is completely self-contained is outside the machine slide system. For example For example, a robotic manipulator can be used and this is typically placed in front of the machine to manipulate parts of a Take up the conveyor and put them in the workpiece-holding chuck of the machine, performing the reverse movement when the machining is finished. Similarly, the automatic Manipulator can be arranged on the rear side of the machine, where it is protected by appropriate rear protective devices reaches through to the exchange of workpieces between the workpiece-holding To accomplish feed and the conveyor system. The end effector is used to speed up the transfer of the workpieces of the robot is typically equipped with two grippers, one to hold "green" or rough workpieces and one to handle the finished ones To hold workpieces. When stepping in1; stretching the robot manipulator arm In the area of the work zone, the end effector is actuated to connect the two pieces with the workpiece-holding one Replace the lining. A major difficulty that arises with

results from these devices according to the state of the art, lies in that the payload size is reduced; d. after two workpieces on the arm must be held, the size of the workpiece is much more limited than in the case where only one workpiece is held by the robot must be kept. Furthermore, the overhang of the robot arm in the work zone can hinder the work carriage and Cause obstruction of the workpiece-holding feed. If a backward Robotic manipulator is used on a machine that has a sloping bed to support the rotary head carriage, so can In addition, the area of the inclined bed the range of the movable Hinder arms in the work zone.

The applicant has the devices according to the state of the art occurring difficulties due to a new part loading and ent charge system overcome, with a robot-like manipulator or Another conveyor is used to bring parts to a "parts offering position" which is a constant point represents relative to the workpiece holding chuck, typically above the headstock. The turret comes with at least one Equipped parts gripper at the tool station, which can be switched between the parts offering position and the workpiece holding chuck or is adjustable, so that under automatic control the rotary head as a replacement device for changing the workpieces from the robot arm acts on the workpiece-holding chuck. In a preferred arrangement, two workpiece-holding chucks or grippers are a corresponding one Associated with a pair of rotary head stations, so that rough or unmachined parts can also be exchanged at the same time can when finished parts are changed. The robot arm is also used to move the / finished parts from the parts-offering position to move to a waiting pendulum conveyor and the rough or unprocessed parts from the conveyor back to the Bringing the parts offering position while the machine is processing the workpiece, so that the robot arm can move required time does not adversely affect the cycle time of the machine. After the robot arm in the present invention only has to handle one workpiece at a time, a much heavier workpiece (typically of the order of magnitude of 2: 1) compared to the state of the art, the two workpiece

holding members used at itsendseiti conditions effector, handled will.

The invention is shown in connection with a lathe, which has a base and a headstock and a rotatable, Has workpiece-holding shaft chuck, which is clamped between and unclamped positions is movable. The machine has a Tool slide assembly which axially and radially with respect to the Headstock shaft on corresponding tool slide coordinates is positionable. A tool turret carried on the tool slide assembly has a plurality of Tool stations, each of which is selective to a first turret position near the workpiece holding chuck and a second turret position away from the workpiece holding chuck

! 5 is adjustable. The position removed from the workpiece-holding chuck is a "parts-offering position" which is operated by a device for transferring raw or unprocessed parts to or from finished parts from the parts-ready position, for example by a robot manipulator . A gripper device, which comprises at least one part gripper, is carried at one of the tool stations and can transfer unprocessed parts to and finished parts from the workpiece-holding chuck via suitable slide movements, and means are provided to open and close the gripper at the to operate the first and the second turret position _s when workpieces are exchanged between the parts offering position and the workpiece-holding chuck.

In the drawing show:

Fig. 1 is a front view of a lathe with the inventive Parts loading and unloading mechanism,

FIG. 2 is a side view of the lathe according to FIG. 1 from the left in Direction of arrow 2 according to FIG. 1,

3 is a front view of a parts gripper taken along line 3-3 according to Fig. 1,

4 shows an axial section through the parts gripper along the line 4-4 according to FIG. 3, and

Fig. 5 is a section through the piston of the parts gripper along the Line 5-5 according to FIG. 4.

Reference is made to the drawings; especially in Fig. 1 a lathe 10 having a base 11 and a spindle head portion 12 is shown. The spindle head portion 12 houses a rotatable shaft 13 and a workpiece holding shaft chuck 14, which is designed so that it carries a workpiece 15 during operation of the machine and drives it in rotation. The lathe 10 has a Inclined bed section 16, which rises upwards to prevent chips from falling down during workpiece machining, and the inclined bed section 16 has tracks 17 which carry a tool slide assembly 18. The tool slide assembly 18 of the machine described has upper and lower slides 19, 20 which can be moved in terms of coordinates, with the lower slide 20 is guided along the inclined bed tracks 17 in a direction parallel to the longitudinal axis of the workpiece 15, and the lower slide 20 has a track system 21 which carries the upper slide 19, which can be moved in the radial direction relative to the workpiece 15 is. Suitable carriage drives 22, 23 are on the inclined bed section 16 for moving the lower slide 20 or on the lower slide 20 for moving the upper slide 19. Of the upper slide 19 carries a rotatable tool turret or rotating head 24 which represents a multi-station arrangement, which so is movable or adjustable that it presents individual tools 25 to the workpiece 15 at the desired machining times.

Certain details of the turret arrangement are not listed here, however, reference is made to U.S. Patent 3,943,802 as an example of an adjustable arrangement which, for example, includes a Can use plurality of boring bars or boring spindles. It is sufficient to understand that the adjuster drive 26 and the gearbox 27 are driven under automatic control in a manner well known in the machine tool art.

An automatic manipulator 28 of the type shown in U.S. Patent 3 909 600 is disclosed, or a similar manipulator as shown on Well known in the field of robots is at the rear of the Machine 10 uses and has an arm 29 that extends over the Spindle head portion 12 of the machine 10 extends, and it has an effector which has an automatic chuck 30 for holding a workpiece 15 (a). The robot chuck 30 is brought to a constant "parts supply station" 31 above the shaft chuck 14, see above that between the robot chuck 30 and the shaft chuck 14 to one an exchange can take place at a predetermined exchange time. The turret 24 is equipped with two parts grippers 32, 33, which the Occupy tool space at two respective tool stations 34,35 so that the carriage 19,20 advances to a point can be where the first gripper 32 (near the value-holding Zone) can come into engagement with a workpiece 15 which is clamped in the shaft chuck 14, and the second gripper 33 is here at a second or remote position relatively in the workpiece-holding shaft chuck 14, which is the parts offering station 31 corresponds. By moving the carriages 19, 20 forward to the respective workpieces 15, 15 (a), and operating the jaws 36, 37 the parts gripper 32, 33, the parts 15, 15 (a) can be gripped and by the corresponding robot chuck 30 or the workpiece holding one Shaft chuck 14 can be removed, and they can exchange their positions with each other, so that an unprocessed part 15 (a) from the Robo-r terfutter 30 can be fed to the workpiece-holding shaft 13 and a finished part 15 from the workpiece holding shaft chuck 14 can be removed and moved back to the robot chuck 30, both happening at the same time. After the . , Exchange has taken place, the turret 24 is adjusted so that it presents the workpiece holding tools 25 as this is required to complete the machining of the workpiece 15 (a). During the machining cycle, the robot arm 29 picks up the finished workpiece 15, which is placed in its robot chuck 30 has been, and transmits it to a remote, not shown Location. The remote location could be a conveyor system that passes behind the machine 10, or a batch location for work pieces, such as a wooden surface. After the completed workpiece 15 has been deposited at the remote location, another one is left untreated

Workpiece 15 (a) picked up and back to parts offering position 31 moved by means of the turret 24 for a subsequent further exchange.

After it is not known in connection with lathes, work pieces to be carried in a parts gripper or chuck, which or which on an adjustable or indexable tool turret head 24 is attached during indexing, illustrates the partial sectional view of the turret assembly of FIG. 1, such as that Grippers 32, 33 can be realized.

The gripper jaws 36, 37 are clamped or opened by means of fluid pressure, which is fed to an inner piston in the gripper 32, 33. These details of the gripper construction are shown in detail in Figs. 3, 4 and 5 explained. Provide fluid pressure lines 38 (a, b) and 39 (a, b) inner openings in the rotatable turret shaft 40, and the Leads are in communication with respective annular grooves 41 (a, b) and 42 (a, b) in the non-rotatable end cap 43, about a rotatable one To create fluid coupling. External hose lines 44 (a, b) and 45 (a, b) serve to the annular grooves 41 (a, b) and 42 (a, b) with two solenoid operated, spring loaded fluid control valves 46, 47 (which are shown symbolically) to connect. Pressurized fluid "P" can be supplied to the grippers 32,33 when in a "parts release" mode is signaled via the (not shown) machine control, whereby the solenoid-operated valves 46, 47 get excited. When the valves 46, 47 are de-energized, the grippers 32, 33 are then clamped again by means of fluid pressure.

Fig. 2 shows an end view of the machine of Fig. 1, wherein it can be seen is that the rearward automatic manipulator 28 with its arm 29 on the spindle head portion 12 of the machine 10 extends in order to realize the parts offering position 31. Workpieces 15 are with the workpiece-holding machine shaft chuck 14 exchanged by means of the adjustable turret 14, which the thereon attached parts gripper 32, 33 carries. During operation, the machine slides 19, 20 are by means of one from the prior art well-known electronic control automatically movable. One control that could be used, for example, is that in

numerical control system described in U.S. Patent 3,703,112 which in principle shows how coordinate slide arrangements of lathes with respect to a shaft held workpiece due to coded commands of an NC control can be moved.

The view shown in FIG. 3 shows the parts gripper 33 or the chuck which is shown at the top of the turret 24 in FIG. 1 is. The lower gripper 32 is identical to the upper gripper 33. The gripper 33 is basically a chuck with three jaws, with three evenly spaced jaws 37 are radially movable in corresponding guide slots 48 in the gripper housing 49. Hold-down plates 50 are provided to prevent the slidable jaws 37 from falling out of the assembly. Each jaw 37 has a jaw guide 51 with a tooth portion 52 extending inwardly into engagement with a central drive gear 53. If that Drive gear 53 is rotated, the radial position of the jaws 37 is varied, thereby clamping and releasing of a workpiece becomes possible. The section shown in FIG. 4 is a partially broken away axial section through the gripper 33 3 and shows that the central drive gear 53 is formed integrally with a rotatable central shaft 54, and the middle part of the journaled shaft 54 is provided with an integral gear 55 which meshes with a pair of Racks 56, 57 are located, which are arranged opposite one another within the gripper housing 49. The jaw guides 51 are with grooved surface 58 to provide repositionable top jaws 59 in the area of workpiece retention to be arranged in a known manner. The gripper housing 59 has a rearwardly extending shaft portion 60 which has a counterbore 61 to receive a stiff spring 62. The shaft section 60 is in the bore 63 of a gripper adapter 64 added, which on the front surface 65 of the turret shaft 40 via threaded bolts 66 and nuts 67,: the hold an adapter flange 68 is attached. The adapter 64 has a cylindrical diameter 69 that is contained in a pocket 70 in the turret shaft 40 is added. The rear, inner one End 71 of the adapter 64 is formed with a cap 72 which is screwed to the adapter 64 to a reaction plate for the

Form spring 62. The inner surface 73 of the cap 72 has a counterbore 74 to receive the spring 62. A transverse one Pin 75 extends radially from shaft portion 60 and lies at the end 76 of a longitudinal slot 77 provided in the adapter 64 is to prevent the gripper housing 49 from moving out of the adapter 64, but with an inward movement of the gripper housing 49 with respect to the adapter 64 is possible. The purpose of the spring preload of the gripper housing 49 is to to allow a certain resilience of the gripper jaws 37 when these against a workpiece, which tolerance variations or positional May have inaccuracies, be printed. The central shaft 54 is by means of a split sleeve 78 which is in a γόη the gear 53 and the gear 55 of the shaft formed recess is inserted, prevented from axial movement with respect to the gripper housing 49. The socket 78 is attached to the gripper housing by means of screws 80 49 attached.

Figure 5 shows a section through the gear 55 and the opposite arranged racks 56, 57 within the gripper housing

49. The racks 56, 57 are formed on identical pistons 81, 82, which are driven in respective cylinders 83, 84. Sealing rings 85 and fluid openings are provided on the pistons 81, 82 86, 87, 88, 89 are connected to the ends of the cylinders 83, 84. It should be noted here that the racks 56, 57 move together and in opposite directions in order to generate a torque acting on the gear 55. The opposite Ends of the racks 56, 57 are therefore in fluid communication with one another and are connected to the turret shaft by means of hoses 90, 91 40 connected to receive corresponding fluid pressure lines 38 (a, b). The hoses 90, 91 or other flexible fluid connections serve to enable the axial movement of the gripper housing 49 with respect to the turret shaft 40.

While the preferred embodiment of the present invention shows a general automatic manipulator 28 for transferring parts between the parts ready position 31 and the remote location transport, other types of conveyor could be used, such as a suitable shuttle conveyor mechanism.

msmus.

While still the invention in connection with a preferred Embodiment has been illustrated and described, the invention is not limited to the illustrated embodiment, rather, it extends to all such constructions and modifications that come within the scope of the claims.

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REFERENCE LIST

10 Lathe 46 Control valve 82 pistons 11th Base 47 Il 83 cylinders 12th Spindle head section 48 Guide slots 84 " 13th wave 49 Gripper housing 85 sealing rings 14th Lining 50 Hold-down plates 86 openings 15th workpiece 51 Jaw guide 87 16 Inclined bed section 52 Tooth section 88 17th Lanes 53 Drive gear 89 18th Tool slide 54 wave 90 hose order 55 gear 91 19th sleds 56 Rack 20th sleds 57 Il 21 Track system 58 surface 22nd Slide drive 59 Head cheeks 23 60 Shaft section 24 Tool turret 61 Counterbore 25th tool 62 feather 26th drive 63 drilling 27 transmission 64 Gripper adapter 28 manipulator 65 Front surface " 29 At the 66 Bolt 30th Lining 67 mother 31 station 68 Adapter flange 32 Part gripper 69 diameter 33 Il 70 bag 34 Tool station 71 end 35 H 72 cap 36 jaw 73 area 37 Il 74 Counterbore 38 cables 75 Pen 39 Il 76 end 40 Turret shaft 77 Longitudinal slot 41 Grooves 78 Rifle 42 ■ 1 79 deepening 43 End cap 80 Screws 44
45 Hose line
Il 81 Pistons

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Claims (5)

PATENT CLAIMS \ J Parts loading system for a lathe with a lasis, a spindle head and a rotatable workpiece-holding shaft chuck which is movable between clamped and unlocked positions, a tool slide arrangement which can be positioned axially and radially with respect to the spindle head shaft, and a tool turret with a plurality of tool stations each of which is selectively adjustable to a first turret position near the workpiece holding chuck and a second turret position remote from the workpiece holding chuck, characterized by a device for transferring untreated parts to and of finished parts removed from the second position from the workpiece-holding chuck, a "gripper device, the at least one parts gripper includes that on the tool turret at one end Telephone agreements only become binding upon written confirmation. of the stations is carried and is operable to deliver untreated parts and finished parts from the transfers the workpiece-holding shaft chuck, and means for operating the gripper (s) between open and closed positions on the first and second turret positions. 2. Apparatus according to claim 1, characterized in that the device for transferring parts is a manipulator includes at least one parts gripper. 3. Device according to claim 1, characterized in that that the device for transferring the parts is a conveyor includes. 4. Device for loading parts with a lathe a base, a spindle head and a rotatable workpiece holder Shaft chuck which can be moved between clamped and unclamped positions, a tool slide assembly, which can be positioned in the axial and radial directions with respect to the spindle head shaft, and with a tool rotating head or turret head, the one Having a plurality of tool stations, each of which is selectively to a first turret position near the workpiece holding chuck and a second turret position remote from the workpiece holding chuck is adjustable, marked by a robot manipulator device with a gripping device for unprocessed and finished workpieces for transferring unprocessed workpieces to and finished workpieces from the second position away from the workpiece holding chuck, two part grippers, which are arranged at corresponding tool stations on the turret head, which can be actuated are to remove unprocessed parts from the Rqboter Manipu- lator device for the workpiece-holding shaft chuck and finished parts to the robot manipulator device from the workpiece holding shaft chuck transferred, and a drive device for selectively actuating the parts gripper between open and closed positions at the first and second turret positions. 5. Apparatus according to claim 4, characterized in that the parts grippers can be actuated to the untreated and to transfer the finished parts at the same time.