CN217617836U

CN217617836U - End effector for robot drilling

Info

Publication number: CN217617836U
Application number: CN202221777033.3U
Authority: CN
Inventors: 庞志愿; 李岸
Original assignee: Shenyang University of Technology
Current assignee: Shenyang University of Technology
Priority date: 2022-07-12
Filing date: 2022-07-12
Publication date: 2022-10-21
Anticipated expiration: 2032-07-12

Abstract

The utility model relates to an end effector of robot system hole, this executor is including feeding the unit, compressing tightly unit, main shaft unit, laser range finder, chassis, guide rail, flange and controller, fixed surface flange under the chassis, the both sides installation guide rail of chassis upper surface, sliding connection feeds the unit and compresses tightly the unit on the guide rail, feeds fixed main shaft unit on the unit, compresses tightly fixed laser range finder on the unit, laser range finder, compress tightly the unit and feed the unit and all be connected with the controller. The utility model discloses realize functions such as normal direction declination detection, packing force control, drilling and countersink integration processing, improve system hole stability and satisfy different camber work pieces, improve system hole quality and efficiency greatly.

Description

End effector for robot drilling

Technical Field

The utility model relates to an automatic field of mechanical assembly specifically is an end effector who relates to a robot system hole.

Background

In the manufacturing process of the airplane, a large amount of hole forming, dimple forming and the like work exist, and the quality of the formed holes determines the overall performance of the airplane to a great extent. The existing hole making technology mostly adopts a special machine tool and manual hole making, is influenced by the size of a workpiece, has limitations, and has the defects of high requirements on experience and quality of technical workers, poor consistency of hole making quality, low efficiency and the like in the manual hole making process. The hole making system of the industrial robot has the advantages of large working space, good flexibility, high hole making efficiency and high hole making precision, and becomes an important technology in the field of automatic assembly of airplanes. However, the industrial robot has the defects of low rigidity and poor stability due to the self open-loop series structure, and vibration caused by insufficient stability during hole making is a main factor of a hole making error of the robot. Therefore, the improvement of the stability of the robot hole making system and the reduction of the weight of the end effector have important significance for improving the hole making quality of the robot.

To sum up, the defects of the prior device are as follows:

1. in order to avoid abrasion between the presser foot and a workpiece, a layer of harder rubber is arranged on the surface of the presser foot of the existing hole making end effector, the workpiece is a convex curved surface, the surface of the presser foot is a plane, the workpiece generates larger deformation due to smaller contact area with the presser foot, so that the dimple precision is reduced, and in addition, the stability of a hole making system is reduced due to poor contact effect between the workpiece and the presser foot, so that the hole making quality is influenced.

2. The existing drilling end effector mostly adopts a double-layer chassis structure, and the pressing unit and the feeding unit are both provided with independent guide rails, so that the end effector has low integral rigidity and large mass.

3. The existing drilling end effector mostly adopts an air cylinder to provide pressing force for a pressing unit, the output force precision of the air cylinder is low, the starting and stopping are unstable, the pollution is easily caused, the noise is high, the stability is poor, and more accessories are provided.

Disclosure of Invention

The utility model provides a robot system hole end effector of light weight type can realize functions such as normal direction declination detection, packing force control, drilling and ream integration processing, improves system hole stability and satisfies different camber work pieces, improves system hole quality and efficiency greatly.

The technical scheme is as follows:

the utility model provides an end effector of robot system hole, this executor is including feeding the unit, compress tightly the unit, main shaft unit, laser range finder, chassis, guide rail, flange and controller, chassis lower surface fixed flange, the guide rail is installed to the both sides of chassis upper surface, sliding connection feeds the unit and compresses tightly the unit on the guide rail, fixes main shaft unit on the feeding unit, compresses tightly the unit and fixes laser range finder, compress tightly the unit and feed the unit and all be connected with the controller.

Furthermore, the pressing unit comprises a pressing foot, an electric cylinder, a pressing mechanism, a first grating scale, a first pressing mechanism head part, a second pressing mechanism head part and a pressure sensor, the electric cylinder is installed on one side face of the chassis and fixedly connected with the pressing mechanism, the pressing mechanism is in sliding connection with the guide rail, the second pressing mechanism head part is fixedly installed on the surface of the pressing mechanism, which is far away from the feeding unit, and the second pressing mechanism head part is in buckling connection with the first pressing mechanism head part; and a preformed hole is formed in the central axis where the second pressing mechanism head part, the pressure sensor, the pressure foot and the first pressing mechanism head part are located, and the pressure foot can penetrate through the preformed hole of the first pressing mechanism head part.

Furthermore, the presser foot comprises a presser foot mechanism, a soft rubber ring and a hard rubber ring, one end of the presser foot mechanism is fixedly connected with the pressure sensor, the annular hard rubber ring is fixedly arranged on the inner annular surface of the concave annular soft rubber ring fixedly arranged on the outer annular surface of the other end of the presser foot mechanism, and the soft rubber ring of the outer ring and the hard rubber ring of the inner ring form a sucker-shaped structure.

Further, the feeding unit comprises a ball screw, a coupler, a servo motor, a workbench slider, a second grating ruler, a first supporting seat and a second supporting seat, the first supporting seat and the second supporting seat are fixedly installed on the upper surface of the chassis, the servo motor is fixedly installed on the rear portion of the chassis through the first supporting seat, the servo motor is connected with the ball screw through the coupler, two ends of the ball screw are installed on the first supporting seat and the second supporting seat through bearings, the ball screw is connected with the workbench slider through threads, two ends of the workbench slider are connected with the guide rail in a sliding mode, and the second grating ruler is fixed on one side face of the chassis.

Furthermore, the spindle unit comprises an electric spindle fastener, a spindle motor and a drill, the spindle motor is fixedly mounted on the workbench slider, the spindle motor is connected with the drill, and the drill can sequentially penetrate through the preformed holes of the pressing mechanism, the second pressing mechanism head part, the pressure sensor, the presser foot and the first pressing mechanism head part.

Furthermore, four laser range finders are arranged and uniformly distributed on the periphery of the head part of the first pressing mechanism, and light rays of the four laser range finders are guaranteed to intersect at one point on the axis of the drill cutter.

Further, the cutter is a drilling and reaming integrated cutter.

The utility model has the advantages that:

1. the structure of the existing presser foot is improved, an outer ring and an inner ring are adopted for design, an annular hard rubber ring is fixedly arranged on the inner ring surface of a concave annular soft rubber ring fixedly arranged on the outer ring surface, the outer ring rubber ring protrudes a certain distance compared with the inner ring rubber ring, after pressing force is applied, the outer ring contacts the surface of a workpiece firstly, and the outer ring deforms due to the fact that the material of the outer ring is soft, and the inner ring contacts the workpiece along with the increase of the pressing force. The workpiece is a convex curved surface, so the design of the concave shape of the outer ring soft rubber ring is more beneficial to keeping good contact. The soft rubber of outer loop plays the function of buffering vibration isolation, improves the stability in system hole, is favorable to reducing the error that arouses because of system vibration in system hole and then improves the system hole precision, can increase presser foot area of contact again and reduce the work piece and warp improvement dimple precision. The hard rubber ring of the inner ring can be used as a reference point for determining the feeding distance because of hard deformation of the material, and is favorable for improving the dimple precision.

2. The compressing unit and the feeding unit share a guide rail, so that the structure is compact, the integral rigidity is high, and the weight is light.

3. The electric cylinder replaces a hydraulic cylinder and is combined with a pressure sensor to form closed-loop control, so that the control of pressing force is more stable.

4. Under the conditions of ensuring the hole-making precision and not influencing the installation, the hole-opening weight-reducing design is carried out on the chassis and the pressing mechanism, so that the quality of the hole-making end effector is reduced.

5. The two grating rulers are used for respectively measuring the feeding amount of the feeding unit and the feeding amount of the compressing unit through displacement compensation, and the dimple precision can be improved.

Drawings

FIG. 1 is a schematic front view of the assembly of the present invention;

FIG. 2 is a first side view of the assembly schematic of the present invention;

FIG. 3 is a second side view of the assembly schematic of the present invention;

FIG. 4 is a perspective view of the hold-down mechanism;

FIG. 5 is an exploded view of the presser foot;

FIG. 6 is an exploded view of the head of the compression unit;

reference numerals are as follows: the device comprises a presser foot 1, a soft rubber ring 1-1, a hard rubber ring 1-2, a presser foot mechanism 1-3, a laser range finder 2, a pressing mechanism 3, an electric cylinder 4, a coupler 5, a servo motor 6, a guide rail 7, a chassis 8, a ball screw 9, a feed unit workbench slider 10, a spindle motor fastener 11, a spindle motor 12, a drill 13, a first grating ruler 14, a second grating ruler 15, a connecting flange 16, a pressure sensor 17, a first pressing mechanism head part 18, a second pressing mechanism head part 19, a first support seat 20, a second support seat 21 and a reserved hole 22.

Detailed Description

The present invention will be described in more detail with reference to the accompanying drawings.

As shown in fig. 1, a robot-made hole end effector includes a feeding unit, a pressing unit, a main shaft unit, a normal direction detecting unit, a chassis 8, a guide rail 7, a connecting flange 16, and a controller, and is connected to a robot through the flange 16. Fixed flange 16 under 8 surfaces on chassis, guide rail 7 is installed to the both sides of 8 upper surfaces on chassis, sliding connection feeds the unit and compresses tightly the unit on the guide rail 7, feed the unit and go up fixed main shaft unit, the main shaft unit cooperatees with compressing tightly the unit, compress tightly the unit and go up fixed normal direction detecting element, normal direction detecting element's laser range finder 2, compress tightly the first grating chi 14 of unit and feed the second grating chi 15 of unit and pass through signal line connection director, electronic jar 4 and servo motor 6 are through servo driver and signal line connection director. The controller was purchased from siemens corporation under the model 200SMART PLC.

The guide rail 7 is of conventional construction and is available from THK corporation of japan under the model number HSR30B2UU. The compressing unit and the feeding unit share the guide rail 7, the structure is compact, the integral rigidity is high, the layout is innovative, and the weight is light. Due to the structural characteristics of the industrial robot in series connection, the industrial robot has the advantages of high flexibility and large working space, but also has the defect of poor rigidity, so that the industrial robot has higher requirements on the weight of an end effector. The end effector is heavier, so that the tail end of the robot generates larger inertia force, the positioning precision of the robot is reduced, the tail end deformation of the robot is increased, the hole making quality is reduced, and the end effector with lighter weight has important significance.

As shown in fig. 1, 4 and 5, the pressing unit includes a presser foot 1, an electric cylinder 4, a pressing mechanism 3, a first grating ruler 14, a first pressing mechanism head part 18, a second pressing mechanism head part 19 and a pressure sensor 17, the pressing mechanism 3 is formed by splicing a plurality of plate bodies, and a structure with an opening in the middle of a connecting slider is arranged below the pressing mechanism 3. The utility model discloses improve current presser foot 1 structure, adopt outer loop inner ring dicyclo design, as shown in fig. 6, presser foot 1 includes presser foot mechanism 1-3, soft rubber circle 1-1 and hard rubber circle 1-2, presser foot mechanism 1-3 is the metal material, its one end and pressure sensor 17 fixed connection, fixed mounting has annular hard rubber circle 1-2 on the annular soft rubber circle 1-1 inner ring surface of indent annular on the outer annular surface of the other end, soft rubber circle 1-1 is compared with hard rubber circle 1-2 and is outstanding certain distance, the soft rubber circle 1-1 of outer loop and the hard rubber circle 1-2 of inner loop form sucking disc column structure, after applying the packing force, the soft rubber 1-1 of outer loop contacts the work piece surface earlier, because its material is softer takes place to warp, inner ring contact work piece along with the increase of packing force. The workpiece is a convex curved surface, so that the concave shape design of the soft rubber ring 1-1 of the outer ring is more favorable for keeping good contact. The outer ring soft rubber ring 1-1 has the function of buffering and vibration isolation, improves the stability of hole making, is beneficial to reducing errors caused by vibration of a hole making system so as to improve the hole making precision, can increase the contact area of the presser foot, reduce the deformation of a workpiece and improve the dimple precision. The hard rubber ring 1-2 of the inner ring can be used as a reference point for determining the feeding distance because the hard deformation of the material is extremely small, and the dimple precision is improved. The large size of the prepared hole 22 of the presser foot 1 causes a large dimple error, and thus the design size is small.

Electronic jar 4 is installed in 8 one sides of chassis and through nut and hold-down mechanism 3 fixed connection, hold-down mechanism 3 is through the slider and the guide rail 7 sliding connection that the bottom set up, electronic jar 4 provides power for compressing tightly the unit, electronic jar 4's flexible hold-down mechanism 3 that drives moves along guide rail 7, the application of packing force can improve the stability of system hole process and the dynamic rigidity of robot system hole system and then improve system hole quality, the stability of packing force influences system hole quality, electronic jar 4 has to open and stop steadily compared in the pneumatic cylinder, the precision is high, good stability, the advantage of environmental protection etc, therefore electronic jar 4 replaces the pneumatic cylinder to use and is favorable to improving packing force stability. A second pressing mechanism head part 19 is fixed on the surface of the pressing mechanism 3 departing from the feeding unit, the second pressing mechanism head part 19 is buckled with the first pressing mechanism head part 18, as shown in fig. 6, a pressure sensor 17 is fixedly installed on the second pressing mechanism head part 19, a pressure foot 1 is fixedly installed on the pressure sensor 17, and a preformed hole 22 is formed on the central axis where the pressing mechanism 3, the second pressing mechanism head part 19, the pressure sensor 17, the pressure foot 1 and the first pressing mechanism head part 18 are located; the diameter of the prepared hole 22 of the first hold-down mechanism head part 18 is slightly larger than the diameter (namely the outer circumference circle) of the hollow cylinder of the head part of the hold-down foot 1, and the hold-down foot 1 can penetrate through the prepared hole 22 of the first hold-down mechanism head part 18 to be abutted on a workpiece to be processed. The first pressing mechanism head part 18 and the second pressing mechanism head part 19 wrap the pressure sensor 17 and the presser foot 1 and are installed on the pressing mechanism 3, the annular pressure sensor 17 is installed behind the presser foot 1 in the pressing unit, pressing force is measured in real time and fed back to the control system to form closed-loop control of force, and therefore the pressing force is kept stable. The first grating ruler 14 is installed on one side of the chassis 8, corresponds to the pressing mechanism 3, and is used for measuring the displacement of the pressing mechanism 3, namely the displacement of the presser foot 1. The electric cylinder 4 is of conventional construction and is commercially available from Shanghai Yi Gem electro mechanical company under the model number SFG-G2-217. The first grating 14 is of conventional construction, available from nordstock, guangzhou, under model number KA-300. The pressure sensor 17 is of conventional construction and is available from the Unionidae ocean corporation under the model number DYHX-003.

As shown in fig. 1-3, the feeding unit includes a ball screw 9, a coupler 5, a servo motor 6, a table slider 10, a second grating ruler 15, a first support seat 20, and a second support seat 21. Servo motor 6 passes through first supporting seat 20 fixed mounting at 8 rear portions on the chassis, servo motor 6 passes through shaft coupling 5 and ball 9 connects, ball 9's both ends are passed through the bearing and are installed at first supporting seat 20, on the second supporting seat 21, first second supporting

seat

20, 21 fixed mounting is on 8 upper surfaces on the chassis, threaded connection workstation slider 10 on ball 9, workstation slider 10's both ends and 7 joints of guide rail, the phase-match, the main shaft motor fastener 11 of fixed spindle unit on workstation slider 10, second grating chi 15 is fixed in 8 one sides on the chassis, corresponding with workstation slider 10, be used for measuring workstation slider 10 sliding distance. The servo motor 6 rotates to drive the ball screw 9 to rotate through the coupler 5, so that the worktable slide block 10 drives the electric spindle 12 of the spindle unit to horizontally move along the guide rail 7 to realize feeding action. In order to prevent the workbench slider 10 from colliding with the compacting structure 3 and the first supporting seat 20, an optoelectronic proximity switch is respectively installed on one side of the compacting structure 3 and one side of the first supporting seat 20 close to the workbench 10. The ball screw 9 is of conventional construction and is available from THK corporation of japan under model number DIK2004-8. The servo motor 6 has the existing structure, is purchased from Shenzhen Shendao automation company, and has the model of SVGC-08C11PD. The second grating ruler 15 is of an existing structure, purchased from norkout, guangzhou, and has a model number of KA-300.

As shown in fig. 1 to 3, the spindle unit includes an electric spindle fastener 11, a spindle motor 12 and a drill 13, the spindle motor 12 is fixedly mounted on the table slider 10 through the motor fastener 11, the spindle motor 12 is connected to the drill 13 through a connector, and the drill 13 can pass through the prepared hole 22 to process a workpiece. The spindle motor 12 controls the speed regulation through a frequency converter. The spindle motor 12 is of an existing structure, is purchased from Shenzhen Song local electric company, and has a model number of GDZ-80-2.2kw.

The perpendicularity of hole making is an important hole making quality index, and in order to guarantee the phase accuracy of the hole making method, the actuator is provided with a normal direction detection unit which consists of 4 laser range finders 2. In order to ensure that the light rays of the four laser range finders 2 intersect at one point on the axis of the drill 13 and the diagonal lines of the laser emission points are perpendicular to each other, the 4 laser range finders 2 are uniformly arranged around the middle hole of the head part 18 of the first pressing mechanism and intersect with the plane of the head part 18 of the first pressing mechanism close to the workpiece by 45 degrees, and the installation mode is favorable for improving the measurement precision. And after the normal deviation is calculated by the normal detection unit, the normal deviation is fed back to the industrial robot control system, so that the robot drives the end effector to align, and the hole-making verticality is ensured. Compared with contact measurement, the non-contact measurement has the advantages of high measurement efficiency, high speed, low possibility of collision, low abrasion to workpieces, high measurement precision and the like. The laser range finder 2 is of an existing structure and is purchased from Shenzhen Mesoh science and technology company with the model number of MT30.

The method comprises the following three aspects of dimple precision control and error source influencing dimple precision, wherein firstly, the existence of pressing force causes workpiece deformation, secondly, the reaction force of the pressing force causes deformation of an industrial robot, and thirdly, the error caused by vibration during hole making is avoided. In the hole making process, because the pressing force exists, the pressing foot 1 is always attached to a workpiece, so that the displacement of the pressing foot 1 is the sum of the deformation of the workpiece, the deformation of an industrial robot and the like, the first grating ruler 14 measures the displacement of the pressing foot 1 in real time, and the displacement of the pressing foot 1 is compensated and fed to the feeding unit. The second grating ruler 15 measures the displacement of the feeding unit in real time and feeds back the position of the motorized spindle 12 to the control system. And the full closed loop feedback control ensures dimple accuracy.

The flange 16 is a round corner square, and the flange 16 is connected with the robot end effector chassis 8 through bolts.

The cutter 13 is a drilling and reaming integrated cutter to complete two procedures of drilling and reaming at one time.

And (3) a hole making end effector work flow:

the method comprises the steps that firstly, the position of a workpiece hole making area is determined by an off-line program system, a robot carries an end effector to be in place, a normal detection unit measures the difference value between a cutter 13 and a curved surface normal vector, the robot carries out error compensation to ensure the requirement of hole making normal precision, then a pressing unit applies pressing force to a workpiece, a presser foot 1 abuts against the workpiece, the presser foot force of the presser foot 1 is measured in real time through a pressure sensor 17, and the presser foot force is kept stable. And then the feeding unit carries the spindle motor 12 to feed, the drill 13 can pass through the reserved hole 22 to process a workpiece, the first grating ruler 14 and the second grating ruler 15 respectively detect the pressure foot 1 and the displacement of the feeding distance and feed back to the controller, when the hole making depth reaches a set value, the feeding unit retracts, then the pressing unit retracts, and one-time hole making operation is completed.

Claims

1. An end effector for robot drilling, characterized in that: the actuator comprises a feeding unit, a pressing unit, a main shaft unit, a laser range finder (2), a chassis (8), a guide rail (7), a connecting flange (16) and a controller, the lower surface of the chassis (8) is fixedly connected with the connecting flange (16), guide rails (7) are installed on two sides of the upper surface of the chassis (8), the guide rail (7) is connected with the feeding unit and the pressing unit in a sliding mode, the main shaft unit is fixed on the feeding unit, the laser range finder (2) is fixed on the pressing unit, and the laser range finder (2), the pressing unit and the feeding unit are all connected with the controller.

2. A robotic hole making end effector as claimed in claim 1, wherein: the pressing unit comprises a pressing foot (1), an electric cylinder (4), a pressing mechanism (3), a first grating ruler (14), a first pressing mechanism head part (18), a second pressing mechanism head part (19) and a pressure sensor (17), the electric cylinder (4) is installed on one side face of the chassis (8) and fixedly connected with the pressing mechanism (3), the pressing mechanism (3) is in sliding connection with the guide rail (7), the second pressing mechanism head part (19) is fixedly installed on the surface of the pressing mechanism (3) departing from the feeding unit, and the second pressing mechanism head part (19) is connected with the first pressing mechanism head part (18) in a buckling mode; inside a second pressing mechanism head part (19) and a first pressing mechanism head part (18), a pressure sensor (17) is fixedly installed on the second pressing mechanism head part (19), a pressure foot (1) is fixedly installed on the pressure sensor (17), a preformed hole (22) is formed in the central axis where the pressing mechanism (3), the second pressing mechanism head part (19), the pressure sensor (17), the pressure foot (1) and the first pressing mechanism head part (18) are located, and the pressure foot (1) can penetrate through the preformed hole (22) of the first pressing mechanism head part (18).

3. A robotic hole making end effector as claimed in claim 2, wherein: the pressure foot (1) comprises a pressure foot mechanism (1-3), a soft rubber ring (1-1) and a hard rubber ring (1-2), one end of the pressure foot mechanism (1-3) is fixedly connected with a pressure sensor (17), the outer ring surface of the other end of the pressure foot mechanism is fixedly provided with the concave annular soft rubber ring (1-1), the inner ring surface of the concave annular soft rubber ring (1-1) is fixedly provided with the annular hard rubber ring (1-2), and the soft rubber ring (1-1) of the outer ring and the hard rubber ring (1-2) of the inner ring form a sucker-shaped structure.

4. A robotic hole making end effector as claimed in claim 1, wherein: the feeding unit comprises a ball screw (9), a coupler (5), a servo motor (6), a workbench slider (10), a second grating ruler (15), a first supporting seat (20) and a second supporting seat (21), the first supporting seat (20) and the second supporting seat (21) are fixedly installed on the upper surface of a chassis (8), the servo motor (6) is fixedly installed on the rear portion of the chassis (8) through the first supporting seat (20), the servo motor (6) is connected with the ball screw (9) through the coupler (5), two ends of the ball screw (9) are installed on the first supporting seat (20) and the second supporting seat (21) through bearings, the ball screw (9) is connected with the workbench slider (10) through threads, two ends of the workbench slider (10) are connected with a guide rail (7) in a sliding mode, and the second grating ruler (15) is fixed on one side face of the chassis (8).

5. A robotic hole making end effector as claimed in claim 1, wherein: the spindle unit comprises a spindle fastener (11), a spindle motor (12) and a drill (13), wherein the spindle motor (12) is fixedly mounted on a workbench slider (10), the spindle motor (12) is connected with the drill (13), and the drill (13) can sequentially penetrate through preformed holes (22) of a pressing mechanism (3), a second pressing mechanism head part (19), a pressure sensor (17), a presser foot (1) and a first pressing mechanism head part (18).

6. A robotic hole making end effector as claimed in claim 1, wherein: the four laser range finders (2) are uniformly arranged on the periphery of a head part (18) of the first pressing mechanism, and the light rays of the four laser range finders (2) are ensured to intersect at one point on the axis of the drill (13).

7. A robotic hole making end effector as claimed in claim 6, wherein: the drill (13) is a drilling and reaming integrated cutter.