MACHINING CELL WITH SEALED ENCLOSURE

Description

[0001] The invention relates to a machining cell with a housing, with a tool-carrying or tool-receiving industrial robot arranged within the housing and with a workpiece table, wherein the housing has at least three sealingly closable operating openings.

[0002] From DE 20 2015 106 871 U1 a machining cell with three machining zones is known, in which the individual workpiece is provided in a workpiece lock closed on both sides with roller shutters.

[0003] EP 3 659 744 A1 and EP 0 650 800 A2 disclose machine tools with pivoting workpiece tables.

[0004] According to EP 2 926 945 A1, a tool changer can be arranged on the roof of a machine tool.

[0005] EP 2 777 871 A1 discloses an enclosed machine tool with a chip conveyor that penetrates an end wall of the enclosure.

[0006] The present invention is based on the problem of processing all workpieces under the same working conditions.

[0007] This problem is solved by the features of the main claim. For this purpose, the machining cell has a chip conveyor. The enclosure has two end walls, two longitudinal walls, and a roof. The first operating opening is a loading opening, which can be closed by means of the workpiece table located between at least two workpiece clamping devices. The second operating opening is a tool change opening located in the roof of the enclosure. The third operating opening is a chip discharge opening, through which the chip conveyor penetrates the enclosure.

[0008] During workpiece machining, each workpiece is located in the same area of the enclosure. The workpiece table, with the workpiece clamped on it, is in one of its working positions. In this working position, one of at least two workpiece clamping devices on the workpiece table is located in the work area of the machining cell. When the workpiece table is moved to another working position, the first workpiece clamping device is moved away from the working position, for example, into a loading and unloading position. Even in this additional working position, the workpiece table seals the enclosure.

[0009] The industrial robot's tool change is performed using a tool changer or manipulator changer located on the roof of the enclosure. The industrial robot or manipulator changer reaches through the open tool change opening. After the tool change is complete, the tool change opening is closed again.

[0010] Chip removal takes place while machining is stopped. For this purpose, the chip discharge opening is opened so that a chip conveyor can transport the chips out of the enclosure.

[0011] The aforementioned operating openings of the enclosure are closed during workpiece processing. They are only opened when machining is stopped.

[0012] Further details of the invention emerge from the subclaims and the following description of schematically illustrated embodiments. Figure 1: Machining cell; Figure 2: Cross section of Figure 1 ; Figure 3: Longitudinal section of Figure 1 ; Figure 4: Enclosure; Figure 5: Sealing of the workpiece table; Figure 6: Tool changer; Figure 7: Cross-section of the machining cell in the conveying direction; Figure 8: End wall of the enclosure with chip discharge opening.

[0013] The Figures 1 - 8 show a machining cell (10) and some of its individual parts. The machining cell (10) has a housing (11) that defines a work space (91). At least one workpiece (1) clamped on a workpiece table (31) is machined in the work space (91). The workpiece is machined by means of a tool-carrying industrial robot (61) that is located within the housing (11). Chips generated during workpiece machining are conveyed out of the housing (11), e.g. after completion of the workpiece machining, by means of a chip conveyor (51).

[0014] The enclosure (11) is at least approximately cuboid-shaped. It has two end walls (12, 13), two longitudinal walls (14, 15) and a roof (16). The end walls (12, 13) delimit the enclosure in the longitudinal direction (5). They are oriented perpendicular to the longitudinal direction (5). The longitudinal walls (14, 15) connect the two end walls (12, 13). The Figure 3 The left end wall (12) and the adjacent longitudinal wall (15) are closed. A flat base plate (22) connects the end walls (12, 13) and the longitudinal walls (14, 15). The machining cell (10) can also be designed without the base plate (22). In the illustrations of the Figures 1 and 2 Control cabinets (92) and switch cabinets (93) are arranged next to the enclosure (11). Maintenance openings or access points can also be provided in the walls (12-15).

[0015] The workpiece table (31) is located in a loading opening (17) in the first longitudinal wall (14). The loading opening (17) is a rectangular opening with a three-sided edge (23). In the illustration of the Figure 4 The length of the loading opening (17) is 4.4 meters. In this embodiment, it has a height of 3.1 meters. The edge (23) has, for example, a constant thickness of 8 millimeters. However, it can also be beveled or thickened in the area surrounding the loading opening (17). The edge can also be formed circumferentially around the loading opening (17). In the Figures 1 - 3 In the working position shown (39), the workpiece table (31) seals the housing (11).

[0016] The workpiece table (31) has a frame (32) in which a workpiece plate carrier (33) with two workpiece clamping devices (35; 36) facing away from each other is pivotally mounted. The workpiece plate carrier (33) is, for example, vertical in the working position (39). The pivoting angle of the workpiece clamping devices (35, 36) about a, for example, horizontal pivot axis (34) is 180 degrees in the exemplary embodiment. A pivot motor (46) arranged on the frame (32) is used for pivoting. In the illustrated working position (39), one of the workpiece clamping sides (38) is outside the housing (11). The other workpiece clamping side (37) is inside the housing (11). To seal it against the housing (11), the workpiece table (31) has, for example, several sealing plates (41) that surround the workpiece clamping devices (35, 36). The sealing plates (41) can, for example,to inflatable air hoses (21) surrounding the loading opening (17) designed as a workpiece lock (17). The loading opening (17) is also referred to below as the first operating opening (17) of the housing (11).

[0017] The Figure 5 shows a further example of sealing the workpiece table (31) relative to the housing (11). The workpiece table (31) has a U-shaped channel (47) running around the workpiece plate carrier (33). A single-part or multi-part air hose (48) is located in this channel (47). The air hose (48) can be inflated and deflated, for example, using a compressed air system. When the workpiece table (31) is in the working position (39), the air hose (48) is loaded so that it forms a seal against the edge (23). Before the workpiece plate carrier (33) is pivoted, the air hose (48) is relieved of load so that its volume is reduced.

[0018] The roof (16) of the housing (11) is, for example, stepped. Two injection nozzles (101, 102) are located on the roof (16) as part of an injection device (100). The injection nozzles (101, 102) penetrate the roof (16). They are aligned at least approximately tangentially to the workpiece table (31) in the working position (39).

[0019] Furthermore, a tool changer (120) is arranged on the roof (16). The tool changer (120) has, for example, a circulating magazine (121) with a plurality of tools (82, 83). These tools (82, 83) are cutting tools in the exemplary embodiment, e.g., drills, milling cutters, grinding pins, etc. The tool changer (120) has a tool holder (122) for each individual tool (82, 83). Below the tool changer (120), the roof (16) has a tool change opening (19). The tool change opening (19) is a second operating opening (19) of the housing (11). A closure cover (24) in the form of a sliding roof (24) is used, for example, to close the tool change opening (19). This sliding roof (24) can be moved between a lowered closed position and an open position along two guide rails. The drive is provided, for example,by means of an electric motor and a rack, a pneumatic or hydraulic cylinder-piston unit, etc. The tool change opening (19) has, for example, a circumferential sealing element (25) for sealing the housing when the sliding roof (24) is closed.

[0020] The housing (11) has a chip discharge opening (18) as its third operating opening (18). Here, the chip conveyor (51) penetrates the second end wall (13) of the housing (11). In the exemplary embodiment, the chip conveyor (51) is a belt conveyor with a revolving conveyor belt (53). When the chip discharge opening (18) is closed, a locking slide (26) in the form of a lifting plate (26) is displaceably mounted on the housing (11) and rests on the upper run (54) of the conveyor belt (53). When the chip discharge opening (18) is open, this has a cross-sectional area with a width of 550 millimeters and a height of 400 millimeters, for example. In the exemplary embodiment, the lifting plate (26) is arranged on the outside of the second side wall (13). It can be moved, for example, in a vertical direction. The drive shown in the figures is a cylinder-piston unit (27), whose piston rod (28) points in the direction of the chip conveyor (51). The use of an electric motor, for example,with a downstream gear unit as a travel drive is conceivable. To seal the chip discharge opening (18), the lifting plate (26) is pressed onto the upper run (54), for example. The area of the chip conveyor (51) between the upper run (54) and the lower run (58) is sealed, for example, by means of adjacent sealing elements. To convey chips from the work space (91) into a container located in the surrounding area (3), the lifting plate (26) is raised by means of the cylinder-piston unit (27). Chip transport takes place, for example, outside of the main workpiece machining time. When the chip discharge opening (18) is closed, the chip conveyor (51) is blocked, for example.

[0021] Furthermore, a sealed suction line (111) penetrates the second end wall (13) of the housing (11). This suction line (111) is part of a suction device (110) of the processing cell (10).

[0022] The industrial robot (61) is arranged within the housing (11). In the exemplary embodiment, the industrial robot (61) is designed as a vertical articulated-arm robot (61). It has a translational main axis (62) and two rotational main axes (63, 64). The translational axis (61), the A-axis (61), is formed by a base rail (65) and a base (66) that can be moved along it. The base rail (65) is oriented in the longitudinal direction (5) of the processing cell (10). A foot lever (67) pivotably mounted in the base (66) and a knee lever (68) pivotably mounted in the foot lever (67) form a kinematic chain of the industrial robot (61). The base (66) and the foot lever (67) form the B-axis (63) as the rotational main axis (63). The foot lever (67) and the knee lever (68) form the C-axis of the so-called TRR kinematics of the six-axis industrial robot (61).

[0023] The first secondary axis (71), the D-axis (71), comprises a support arm (74) rotatable about its longitudinal axis, which is mounted at the free end of the toggle lever (68). The second secondary axis (72) is the E-axis (72), about which a hand lever (75) is pivoted by, for example, 270 degrees. The hand lever (75) supports a turntable (76) pivotable through 360 degrees, which is rotatably mounted about the F-axis (73). The machining unit (81) is attached to the turntable (76).

[0024] In the exemplary embodiment, the processing unit (81) comprises a plurality of driven tools (82, 83). These are, for example, drilling tools (82), sawing tools (83), etc. These tools (82, 83) can be driven individually or in groups.

[0025] In order to change a tool (82, 83) of the machining unit (81), the tool changer (120) is used. For this purpose, after the second operating opening (19) has been opened, the machining unit (81) is moved such that it protrudes at least partially from the roof (16). For example, a drilling tool (82) protrudes upwards into the area of the tool changer (120). This drilling tool (82) is then taken over by the tool changer (120). The tool changer (120) is now indexed, for example, until a new tool (82; 83) is located in the takeover area of the machining unit (81). After the new drilling tool (82) has been inserted, for example, into the machining unit (81), the latter is moved back into the work space (91) by means of the industrial robot (61). The tool change opening (19) is then closed again. When using a manipulator changer, this accesses, for example,from the outside with the new tool through the tool change opening (19) in order to carry out the tool change on the processing unit (81) of the industrial robot (61).

[0026] Each workpiece clamping device (35, 36) of the workpiece table (31) has a plurality of workpiece clamping elements (42). The workpiece (1) is held on the workpiece clamping device (35; 36) by means of these, for example, pneumatically operated workpiece clamping elements (42). In the exemplary embodiment, both workpiece clamping devices (35, 36) are of identical design. The workpiece clamping elements (42) are arranged, for example, in a matrix-like manner in columns and rows. The individual workpiece clamping element (42) is, for example, a telescopic element that can be extended and retracted pneumatically. An electric or hydraulic drive for the workpiece clamping elements (42) is also conceivable. The lifting device of each workpiece clamping element (42) can be controlled individually. On its side projecting towards the workpiece clamping side (37; 38), the individual workpiece clamping element (42) has a suction cup (43) which is connected to a vacuum pump via a valve control.The vacuum control of each individual workpiece clamping element (42) is provided by a separate, individually switchable valve. The individual valve is, for example, an electromagnetically actuated 2 / 2-way valve with an open and a closed switching state. The extended workpiece clamping elements (42) form a workpiece clamping surface (45).

[0027] In order to clamp a workpiece (1) onto the workpiece table (31), it is clamped onto the workpiece clamping device (36) located outside the housing (11). To do this, for example, those workpiece clamping elements (42) that support the workpiece (1) are extended. For example, alignment stops can also be extended. All other workpiece clamping elements (42) remain in their retracted starting position. The extended workpiece clamping elements (42) are subjected to negative pressure and the workpiece is placed in alignment. It is also conceivable, for example, to clamp more than one workpiece onto the workpiece table (31) for machining smaller workpieces (1).

[0028] The position of the workpiece (1) to be machined on the workpiece table (31) can also be determined optically. For this purpose, a camera, for example, is used to capture the position of the workpiece contour relative to the contour of the workpiece clamping device (35; 36). The position of the workpiece relative to the machine-related reference coordinates can then be transmitted to the control system for workpiece machining.

[0029] The workpiece plate carrier (33) is then pivoted about the pivot axis (34) so that the previously external workpiece clamping device (36) moves into the work space (91). The workpiece clamping device (35) previously located in the work space (91) is pivoted outwards. The workpiece located on this first workpiece clamping device (35) can now be removed and a new workpiece (1) to be machined can be clamped on. This can be done manually or by means of a handling device. The workpiece (1) is machined in the work space (91). The individual workpiece (1) is, for example, a wooden plate, a composite material plate, a metal plate, etc. In the case of a metal plate, this can be, for example, an aluminum plate. In this exemplary embodiment, the machineable workpiece (1) has a maximum length of 3600 millimeters and a maximum width of 2100 millimeters.When the workpiece (1) is clamped on the workpiece table (31), the workpiece width is oriented in the height direction (6) of the machining cell (10).

[0030] The chip conveyor (51) is located below the workpiece table (31) in the work area (91). The upper run (54) of the conveyor belt (53) lies under the entire length of the workpiece table (31) oriented in the longitudinal direction (5) of the machining cell (10). The conveyor belt (53) of the chip conveyor (51) penetrates an end wall (13) of the housing (11) through the chip discharge opening (18) in its conveying direction (55).

[0031] The suction device (110) comprises, for example, a suction pump located outside the housing (11) with a filter and / or separator device for separating the extracted solid particles from the suction stream. Within the housing (11), the suction device (110) has a suction channel (112) adjacent to the upper side of the upper run (54), which opens into a suction nozzle (113) oriented in the longitudinal direction (5). The suction nozzle (113) is closed, for example, on the side facing away from the suction pump. The suction line (111) connects the suction nozzle (113) to the suction pump.

[0032] The delivery capacity of the suction device (110) is adjustable. For adjustment, for example, the volume flow delivered by the suction pump is adjusted. This is achieved, for example, by adjusting the speed of the suction pump's drive motor.

[0033] Control cabinets (92) of the processing cell (10) are located next to the enclosure (11). The control systems located in the control cabinets (92) control and monitor all processes related to material flow and processing in the processing cell (10). Cooling air is drawn in from the ambient air (3) for cooling.

[0034] To enable workpiece processing, all access and operating openings (17-19) of the enclosure (11) are closed, for example. This is monitored, for example, by contact switches. The industrial robot (61) moves the processing unit (81) such that at least one tool (82, 83) contacts the workpiece (1). The workpiece (1) is machined, for example, using dry machining.

[0035] During machining of the workpiece (1), the blowing device (100) is switched on. The blowing device (100) blows compressed air, for example, by means of a fan through two blowing nozzles (101, 102) into the work chamber (91). The blowing device (100) can be operated continuously or intermittently. The internal pressure of the work chamber (91) is, for example, lower than the ambient air pressure (3).

[0036] The air flow of the injection device (100) is directed in the working space (91), for example, toward the tool engagement area and its immediate surroundings. The use of a pivoting injection nozzle (101; 102) is also conceivable. The pivot axis of the injection nozzle (101; 102) can be oriented horizontally and / or vertically.

[0037] The chips generated during machining of the workpiece (1) fall onto the stationary chip conveyor (51) or are blown down onto it. Finer dust, such as grinding dust, is sucked into the extraction channel (112) by the extraction device (110). The pressure difference between the work chamber (91) and the surrounding area (3) as well as the sealed enclosure (11) prevent contaminants from escaping into the surrounding area (3).

[0038] After completing processing of the workpiece (1), the industrial robot (61) returns to its starting position. During this time, the suction device (110) and, if applicable, the injection device (100) continue to operate for a short period of time. This can occur during a fixed time interval, e.g., 5 seconds. Subsequently, for example, as soon as the industrial robot (61) has reached its parking position, the opening of the housing (11) is authorized.

[0039] However, it is also conceivable to deactivate the blowing device (100) and the suction device (110) using a signal from a dust sensor. For this purpose, the dust sensor, for example, has a light barrier for indirectly detecting the dust load. If the dust load falls below a preset threshold, the opening of the enclosure (11) is authorized.

[0040] After the opening is authorized, the workpiece table (31) is pivoted so that the machined workpiece (1) can be removed. The industrial robot (61) can change the tool (82, 83) using the tool changer (120), as described above. The chip discharge opening (18) is opened so that the chip conveyor (51) conveys the chips generated during machining out of the housing (11). This conveying process takes, for example, 10 seconds. While the workpiece table (31) is pivoting, the next workpiece (1) enters the work area (91).

[0041] The three operating openings (17-19) are then closed again. The next workpiece (1) can now be machined. Machining proceeds as described above.

[0042] The three operating openings (17-19) are located in different walls of the enclosure (11). This separates the material movements through these openings (17-19). They can be carried out in parallel. This results in short downtimes.

[0043] The workpiece table (31) remains in the same position in the workspace (91) for each workpiece processing operation. The airflow at the workstation can be kept largely constant during processing. This ensures consistent working conditions for each workpiece processing operation. The machining cell (10) has only a few moving parts. This minimizes control effort. List of reference symbols:

[0044] 1Workpiece 3Environment 5Longitudinal direction 6Height direction 10Machining cell 11Enclosure 12End wall of (11) 13End wall of (11) 14Longitudinal wall of (11) 15Longitudinal wall of (11) 16Roof 17Feed opening, first operating opening 18Chip discharge opening, third operating opening 19Tool change opening, second operating opening 21Air hoses, seal 22Bottom of (11), base plate 23Edge of (17) 24Closing cover for (19), sliding roof 25Sealing element 26Closing slide, lifting plate 27Cylinder-piston unit 28Piston rod 31Workpiece table 32Frame 33Workpiece plate carrier 34Pivoting axis 35Workpiece clamping device 36Workpiece clamping device 37Workpiece clamping side 38Workpiece clamping side 39Working position 41Sealing plates 42Workpiece clamping elements 43Suction cup 45Workpiece clamping surface 46Swivel motor 47Channel 48Sealing element, inflatable hose element, air hose 51Chip conveyor 53Conveyor belt 54Upper run 55Conveying direction 58Lower run 61Industrial robot,Vertical articulated arm robot 62 Translational axis, A-axis 63 Rotary main axis, B-axis 64 Rotary main axis, C-axis 65 Base rail 66 Base 67 Foot lever 68 Knee lever 71 Secondary axis, D-axis 72 Secondary axis, E-axis 73 Secondary axis, F-axis 74 Support arm 75 Hand lever 76 Turntable 81 Machining unit 82 Tool, drilling tool 83 Tool, sawing tool 91 Work area 92 Control cabinets 93 Switch cabinet 100 Injection device 101 Injection nozzles 102 Injection nozzle 110 Extraction device 111 Extraction line 112 Extraction channel 113 Extraction nozzle 120 Tool changer 121 Circulating magazine 122 Tool holder,

Claims

1. A machining cell (10) having an enclosure (11), having a tool-carrying or tool-holding industrial robot (61), which is arranged inside the enclosure (11), and having a workpiece table (31), wherein the enclosure (11) has at least three sealingly closable operating openings (17 - 19), characterised in that - the machining cell (10) has a chip conveyor (51), - the enclosure (11) has two end walls (12, 13), two long walls (14, 15) and a roof (16), - the first operating opening (17) is a loading opening (17), which is closable by means of the workpiece table (31), which has at least two workpiece-mounting devices (35, 36), - the second operating opening (19) is a tool-changing opening (19), which is arranged in the roof (16) of the enclosure (11), and - the third operating opening (18) is a chip discharge opening (18) in which the chip conveyor (51) penetrates the enclosure (11).

2. The machining cell (10) according to Claim 1, characterised in that the workpiece table (31) has a frame (32) and a workpiece plate carrier (33), which is adjustable about a horizontal pivot axis (34) or rotational axis relative to the frame (32).

3. The machining cell (10) according to Claim 2, characterised in that the workpiece plate carrier (33) has at least two workpiece-mounting devices (35, 36) oriented in different directions.

4. The machining cell (10) according to Claim 2, characterised in that at least one sealing element (48) is arranged on the workpiece plate carrier (33) in a plane accommodating the pivot axis (34).

5. The machining cell (10) according to Claim 4, characterised in that at least one sealing element (48) is an inflatable hose element.

6. The machining cell (10) according to Claim 1, characterised in that a tool changer (120) is arranged on the enclosure (11).

7. The machining cell (10) according to Claim 6, characterised in that the tool changer (120) has a plurality of tool holders (122), which are arranged on a common circulating magazine (121).

8. The machining cell (10) according to Claim 1, characterised in that the tool-changing opening (19) is closable by means of a sliding roof (24).

9. The machining cell (10) according to Claim 1, characterised in that the enclosure bears a closure slide (26), which can be applied to the chip conveyor (51).