US20190168286A1

US20190168286A1 - Three dimensional wire bending apparatus

Info

Publication number: US20190168286A1
Application number: US16/167,090
Authority: US
Inventors: Seyed Mohammad Mirtaheri; Hassan Zohoor
Original assignee: Department Of Mechanical Engineering South Tehran Branch Azad University; Seyed Mohammad Mirtaheri
Current assignee: Department Of Mechanical Engineering South Tehran Branch Azad University; Seyed Mohammad Mirtaheri
Priority date: 2017-10-29
Filing date: 2018-10-22
Publication date: 2019-06-06

Abstract

An improved system for automatically shaping wires includes two movable robotic arms each having a certain degree of freedom of movement, and each having a mechanism for holding a wire in place and a rotational bending unit for creating the desired shape on the wire. Each of the two robotic arms is positioned on a movable unit to enable their linear motion, while various pulleys connected to motors provide for movement of various links that form each arm. The system enables an operator to move the workpiece wire in three-dimensional space using a controller. By positioning the workpiece in the desired position and using a rotational bending unit, highly precise angular bends can be created on the workpiece.

Description

CROSS REFERENCE TO RELATED APPLICATION

This application claims the benefit of priority to Iran Application Serial Number 139650140003009064, filed on Oct. 29, 2017, the entire content of which is incorporated herein by reference.

TECHNICAL FIELD

The present application relates generally to automatically bending wires, and more particularly to an improved system and method of automatically bending wires into precise three-dimensional shapes using a robotic system.

BACKGROUND

Wires have different applications in a variety of industries and for each different application, a different shape of wire may be needed. Moreover, the desired products may require wires having different diameters and dimensions. To accommodate this, various types of wire bending devices have been developed. As the field of uses for bent wires has expanded, the methods by which the various wire bending devices perform their functions have become ever more complex and more specialized.
At present, there are several devices that create various forms on wires or metal rods. Most of these devices includes a wire feed section through which the input wire is pulled into the device by two reels and passed through a straightening section, which may be a roller, before entering the bending section of the device. In the bending section, the wire moves past the bending head which create the desired shape on the wire.
One of the main issues encountered in the operation of these wire bending devices is that the error tolerances for wire bends are often smaller than the error margins of the device, which means that several pieces out of each production run will be unsuitable for their intended use. Other limitations of such prior art devices include only providing two-dimensional bending, limitations on the complexity of the shapes possible, and restrictions on the forms of wires that can be input into the device.
Therefore, a need exists for providing an improved system and method of automatically bending wires which is efficient and accurate and provides three-dimensional bending while allowing for various types of wires to be used as input.

SUMMARY

A system for automatically shaping wires is disclosed. In one implementation, the system for automatically shaping wires includes a base support, a straightening mechanism positioned on one end of the base support for receiving and straightening an input wire, two articulated robotic arms having approximately the same size and the same shape, each robotic arm including a plurality of pivotable links, two railing mechanisms, each positioned on one longitudinal side of the base support and each connected to one of the two articulated robotic arms for enabling linear movement of the two articulated robotic arms, a clamping mechanism attached to one of the plurality of pivotable links for holding the input wire in place, a bending unit located adjacent to the clamping mechanism for shaping the input wire, a cutting mechanism for cutting the shaped wire as needed, and a controller for controlling the operation of the system. Each robotic arm may be movable in a longitudinal linear direction along the base support and each robotic arm may have a predetermined degree of freedom of movement.

BRIEF DESCRIPTION OF THE DRAWINGS

Features of the subject technology are set forth in the appended claims. However, for purpose of explanation, several implementations of the subject technology are set forth in the following figures.

FIG. 1 is a schematic drawing of an angular front view of an improved system for automatically bending wires into predetermined shapes.

FIG. 2 is a schematic drawing of angular back view of an improved system for automatically bending wires into predetermined shapes.

FIG. 3 is a schematic drawing of a side view of an improved system for automatically bending wires into predetermined shapes.

FIG. 4 is a schematic drawing of a top view of an improved system for automatically bending wires into predetermined shapes.

FIG. 5 is a schematic drawing of a back view of an improved system for automatically bending wires into predetermined shapes.

FIGS. 6A-6B are schematic drawings of angular views of a clamping and bending mechanism for an improved system for automatically bending wires into predetermined shapes.

FIG. 6C is a schematic drawing of a back view of a robotic arm for an improved system for automatically bending wires into predetermined shapes, the robotic arm having a clamping and bending mechanism.

DETAILED DESCRIPTION

In the following detailed description, numerous specific details are set forth by way of examples in order to provide a thorough understanding of the relevant teachings. However, it should be apparent to those skilled in the art that the present teachings may be practiced without such details. In other instances, well known methods, procedures, components, and/or circuitry have been described at a relatively high-level, without detail, in order to avoid unnecessarily obscuring aspects of the present teachings. As part of the description, some of this disclosure's drawings represent structures and devices in block diagram form in order to avoid obscuring the invention. In the interest of clarity, not all features of an actual implementation are described in this specification. Moreover, the language used in this disclosure has been principally selected for readability and instructional purposes, and may not have been selected to delineate or circumscribe the inventive subject matter, resort to the claims being necessary to determine such inventive subject matter. Reference in this disclosure to “one embodiment” or to “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the invention, and multiple references to “one embodiment” or “an embodiment” should not be understood as necessarily all referring to the same embodiment.
Most currently used wire bending devices are limited in the form of input wire they can receive. Some of these types of wire bending devices only provide two-dimensional bending of wires. Moreover, these devices are often inefficient, use a lot of energy to operate and lack a high degree of accuracy.
A solution is proposed here to solve these issues and more by providing an improved system and method of automatically forming wires into three-dimensional shapes using a robotic device. The robotic device may include two articulated robotic arms, each with an available degree of rotation, and each having a mechanism for holding the wire and a rotational bending unit for creating the desired form. Each of these two arms may be on a movable platform to enable their linear motion. The two arms along with other parts of the system form a computer numeric control (CNC) tool for creating precise three-dimensional shapes on wires. The robotic device enables an operator to move the workpiece wire in three-dimensional space using a 10-axis controller. By positioning the workpiece in the desired position and using a rotational bending unit, highly precise angular bends can be created on the workpiece. The bends and arches on the workpiece can be made in accordance with predetermined design parameters. Such a CNC machine can be used in the wire industry to produce products in which metal beads are used with different shapes and sections.
The input wire used by the improved system of automatically forming wires can be in a variety of forms. For example, the input wire can be in the form of rods or pipes which have been straightened and cut, or it could be in the form of coils. If cut pieces are used as input wire feeds, the robotic arms can pick them up from predetermined areas around the device and can place the final product in a specific place after the completion of the forming steps. When a coil is used as the input feed, the coil may pass through a straightening portion first before being cut in a desired length and formed. The tensile strength of the wire for passing through the straightening portion may be provided by the robotic arms.
FIGS. 1 and 2 depict front and back angular views, respectively, of a system 100 for automatically shaping wires. System 100 includes three main portions, a straightening portion, a cutting portion, and robotic arms, all of which are attached to a base support. The base support may be table having a top surface 3, four legs 2, and a side support unit 5. The side support unit 5 may provide a bearing casing for a ball screw shaft. The top surface 3 may include an opening for allowing one or more components of the system 100 to pass through.
The straightening portion provides a straightening mechanism by including a horizontal set of rollers 32 and a vertical set of rollers 34, the two sets being orthogonal with respect to each other. The horizontal set 32 includes two rows of rollers adjacent to each other, with a pathway in between the two rows for a wire 1 to pass through. In one implementation, a first row of the two rows includes one more roller than a second row, such that the rollers in the second row are positioned across from the space where two adjacent rollers of the first row meet. For example, the first row may include four rollers (as shown in FIGS. 1 and 2) and the second row may include three rollers for a total of seven horizontal rollers. The vertical set includes several rollers positioned vertically, behind which the wire can pass. In this manner, the rollers in the horizontal set 32 eliminate any curvature existing in the wire in the horizontal plane, while the rollers in the vertical set flatten any curvature in the vertical plate. To straighten the wire, the rollers may include a semicircular or v-shaped groove on their surface. In one implementation, the rollers are fabricated from hard materials to increase their rigidity and lifetime. The rollers' groove surface may have a smooth finish. The rollers are arranged in upper and lower rows to cause plastic deformation in the wire (i.e., damped sinusoidal pathway) by synchronizing residual stresses to make the wire straight. The wire pathway through the rollers is such that the change in plasticity of the workpiece wire is gradual and when the wire nears the final rollers in the set through which it is passing, less tensile force is applied to the wire. The tensile force required to pass the wire through the rollers is provided through the two robotic arms.
The cutting portion of the system 100 includes a cylindrical shape cutting die 26 through an opening of which the workpiece wire can pass and a cutting arm 27 located adjacent to the cutting die 26 for cutting the wire that passes through the cutting die 26. The cylinder cutting die 26 may be made from a material, such as tungsten carbide, and the cutting die 26 may be configured to hold the wire in place while it is being cut. The cutting die 26 and the edge of cutting arm 27 impose a shear force to cut the wire. The wire may be cut before being bent or it may be cut after as part of the shaping process. The cutting arm 27 may be connected to a flywheel 28 via a connecting unit 36. The flywheel 28 is in turn connected to a motor 30 via an anchor shaft and a gearbox 31, as illustrated in FIGS. 1 and 5. The motor 30 can move the anchor shaft 29 which would in turn rotate the flywheel 28 and thus via the connecting link 36, the cutting arm 27. In this manner, the system is able to provide a mechanism for cutting the workpiece wire at the right time.
The robotic arms portion of the system 100 includes two robotic arms of equal size and shape, each having a certain degree of freedom of movement. In one implementation, the degree of freedom for each robotic arm is 5 degrees. In other implementations, the degree of freedom may be larger than 5 degrees or may be different for each arm. As shown in FIG. 3, which depicts a side view of the system 100, each robotic arm includes three pivotable links. These links include a first movable link 9, a second movable link 10 and a third movable link 11, which may act as an end effector. These pivotable links are connected via shafts (not shown) that enable their movement along a desired axis, as illustrated in FIG. 3. For example, the first movable link 9 and second movable link 10 can pivot in the vertical direction by 180 degrees, thus enabling the links to move forward and backwards as needed. The third movable link 11 can also move up and down about an axis parallel to the longitudinal axis of system 100.
The torque required to pivot the tilted link 9 may be provided by a motor 21 and a gearbox 22, which is provided to reduce the angular velocity and increase the torque of a shaft connected to the movable link 9. The torque may be applied to a unit 23 which passes through an opening in the bottom of the tilted link 9. The motor 23 can transfer its power to the unit 24 and in turn to pulleys 17 and 18 to pivot the first movable link 9 in a desired direction and angle. The second movable link 10 can be moved through a torque applied by the motor 23 and gearbox 24 to a pulley 17, which is connected through a belt (not shown) to a smaller pulley 18. The pulley 18 is connected to the second movable link 10 via a shaft (not shown) that passes through an opening of the second movable link 10. In one implementation, the shaft passes through two openings (not shown) on the upper portion of the first movable link 9 and one opening of the second movable link 10, thus in this manner connecting the first movable link 9 to the second movable link 10. Rotation of the pulley 17 causes a belt that passes through the pulley 17 and pulley 18 to move, thus moving pulley 18. As a result, the shaft connected to the pulley 18 rotates, thus moving the second movable link 10 by a desired degree. In one implementation, a motor 21 supplies the torque required to rotate the first movable link 9 through gearbox 22 and a shaft of the first movable link 9 which has bearings located on a movable platform 8. The third movable link 11 can in turn, be rotated via a motor (actuator) 25 which has a shaft connected to a pulley 19. The pulley 19 is connected to a pulley 20, via a belt. The pulley 20 is attached to the third movable link 11 via a shaft (not shown) that passes through an opening in the third movable link 11 (not shown). In this manner, the rotation of pulley 20 caused by the belt that passes through both pulleys 19 and 20 causes the shaft connected to pulley 20 to rotate, thus movable the third movable link 11 can be moved separately as needed. It should be noted that the actuator (i.e. motor) for each link is located on a previous link to move the center of mass away from end effector. In this manner, each of the first, second, and third movable links 9, 10, and 11 can be moved separately, each having an individual degree of freedom.
Each first movable link 9 is coupled to a movable platform 8 which is itself attached to an element 7 having an opening through which a screw 40 passes The screw 40 is the screw of a ball screw system for transferring power for linear movement of each robotic arm. The nut for the ball screw system is connected to element 7. This mechanism enables linear longitudinal movement of each robotic arm along the length of the base support through a railing mechanism 4. In one implementation, this linear movement is provided by a Linear Motion Guide (LMG) which provides a linear rolling motion. The force required for the linear motion of each robotic arm may be provide by a servo motor 6. The existence of two robotic arms in the circumference of the longitudinal axis of the machine enables the system 100 to tighten, rotate and bend the workpiece wires in different sizes and shapes.
FIGS. 6A-6C depict one or more components of the system 100 used for keeping the workpiece wire 1 in place and bending or shaping the wire as needed. In one implementation, these components are attached to the third movable link 11. The components used for keeping the wire 1 in place include a clamp formed from a stationary unit 15 and a movable unit 14. The two units 14 and 15 form a clamp that can be opened to place a workpiece wire inside and closed to retain the wire in place, when needed. The clamp is opened and closed by moving the movable unit 14 up and down. This may be achieved by movement of a motor 12, which is attached to a shaft connected to the movable unit 14. Once the wire is in place and the clamp is closed, the wire can be shaped using a movable bending unit 13. The bending unit 13 can be moved via a motor and gearbox unit 16, as illustrated in FIG. 4, which provides a top view of the system 100. The movable bending unit 13 can rotate both clockwise and counterclockwise and move up and down and/or to the sides to provide the desired form for the workpiece wire. Thus, the movable bending unit is configured to shape the workpiece wire on both sides of the clamping mechanism and in both clockwise and counterclockwise directions. The curvature on the movable unit 15 and stationary unit 14 provides surfaces against which the wire can be pressed and shaped as needed. In one implementation, the clamp on one of the robotic arms can hold the wire in place, while the bending unit 13 of the other robotic arm generates the desired shape on the wire. The clamp on each robotic arm can be used to hold the input wire as the wire enters the system through the rollers of the straightening section. The clamp can also be used to pick up the input wire from a designated location around the system 100 and to drop off the shaped wires to another designated location once the bending are cutting operations are completed. This is illustrated in FIG. 4. Thus, by providing two movable arms each of which includes multiple movable links, the system 100 offers a mechanism for flexibly forming a workpiece wire into any desired shape.
FIG. 5 depicts a view from the back of the system 100, illustrating how the cutting arm is connected to the motor 30 and how the two robotic arms can operate simultaneously to shape a workpiece wire.
The actions of the various motors in the system 100 may be controlled by one or more controllers that can be connected to a computing device such as desktop computer, mobile device, tablet, and any other device that can function as a computing device for communicating with a controller of the system 100. The controller may include a processor and a memory for storing instructions executable by the processor to control the movement of the various components of the system. In one implementation, one or more controllers, one or more motor drivers, and a power circuit for providing power to the system are located inside a panel 35. The panel 35 may include one or more power and communication ports for communicating with a computing device and providing power to the system 100. In one implementation, the design parameters of the bends and arches desired in the final shape of the wire, along with the sequence with which they should be created may be set by a designer using a software program associated with the system 100. The software program may provide one or more user interfaces for allowing a user to choose the types and angles of bends desired on a workpiece wire and how and when each bend should be created. Once the design is set, a corresponding program for operation of the system may be transferred to the system 100 via one or more communication ports on the panel 35. The required steps may then be executed on the workpiece wire by the system 100 in accordance with the predetermined design. In one implementation, the controller may be connected to the computing device, while the system 100 is performing a function, such they a user can interact with the system 100 and view the current step of the program being executed.
Accordingly, the improved system for automatically shaping wires provides a lightweight, precise and inexpensive device for efficiently forming wires into various shapes. The improved system may include two robotic arms, each an available degree of rotation, and each having a mechanism for holding the wire and a rotational bending unit for creating the desired form. This enables one arm to perform a bending action, while the other arm acts as a retaining clamp for holding the workpiece wire in place. It also provides the ability to simultaneously create two bends on a workpiece, thus reducing production time. In simultaneous bending, each robotic arm may create a bend on a workpiece.
In this manner, the improved system for automatically shaping wires eliminates one of the main shortcomings of currently available technology which is low flexibility and insufficient work space. By using two movable arms, each having a certain degree of freedom of movement, restrictions on possible shapes for the wire are reduced, while the final shape can be created in several different ways. As a result, more complex shapes can be created, while optimizing energy consumption, and increasing the accuracy and speed of the process.
The improved system also provides the ability to use various types of wires as input, such as coils, rods, wires having non-circular shapes, thickly walled pipe wires, and long wires. This enables the device to be used for shaping wires for a lot of industries that are not normally possible with currently used systems. For example, by being able to form long wires, the improved system can shape wires used in constructing buildings.
Thus, the improved system for automatically shaping wires can be used in a variety of industries such as manufacturing appliances, building construction materials, military and hardware industries, medical supplies, automotive industry and the like to provide wires in a variety of shapes and sizes.
The separation of various components in the examples described above should not be understood as requiring such separation in all examples, and it should be understood that the described components and systems can generally be integrated together in a single packaged into multiple systems.
While the foregoing has described what are considered to be the best mode and/or other examples, it is understood that various modifications may be made therein and that the subject matter disclosed herein may be implemented in various forms and examples, and that the teachings may be applied in numerous applications, only some of which have been described herein. It is intended by the following claims to claim any and all applications, modifications and variations that fall within the true scope of the present teachings.
Unless otherwise stated, all measurements, values, ratings, positions, magnitudes, sizes, and other specifications that are set forth in this specification, including in the claims that follow, are approximate, not exact. They are intended to have a reasonable range that is consistent with the functions to which they relate and with what is customary in the art to which they pertain.
The scope of protection is limited solely by the claims that now follow. That scope is intended and should be interpreted to be as broad as is consistent with the ordinary meaning of the language that is used in the claims when interpreted in light of this specification and the prosecution history that follows and to encompass all structural and functional equivalents. Notwithstanding, none of the claims are intended to embrace subject matter that fails to satisfy the requirement of Sections 101, 102, or 103 of the Patent Act, nor should they be interpreted in such a way. Any unintended embracement of such subject matter is hereby disclaimed.
Except as stated immediately above, nothing that has been stated or illustrated is intended or should be interpreted to cause a dedication of any component, step, feature, object, benefit, advantage, or equivalent to the public, regardless of whether it is or is not recited in the claims.
It will be understood that the terms and expressions used herein have the ordinary meaning as is accorded to such terms and expressions with respect to their corresponding respective areas of inquiry and study except where specific meanings have otherwise been set forth herein. Relational terms such as first and second and the like may be used solely to distinguish one entity or action from another without necessarily requiring or implying any actual such relationship or order between such entities or actions. The terms “comprises,” “comprising,” or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. An element proceeded by “a” or “an” does not, without further constraints, preclude the existence of additional identical elements in the process, method, article, or apparatus that comprises the element.
The Abstract of the Disclosure is provided to allow the reader to quickly ascertain the nature of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. In addition, in the foregoing Detailed Description, it can be seen that various features are grouped together in various implementations for the purpose of streamlining the disclosure. This method of disclosure is not to be interpreted as reflecting an intention that the claimed implementations require more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive subject matter lies in less than all features of a single disclosed implementation. Thus, the following claims are hereby incorporated into the Detailed Description, with each claim standing on its own as a separately claimed subject matter.

Claims

What is claimed is:

1. A system for automatically shaping wires comprising:

a base support;

a straightening mechanism positioned on one end of the base support for receiving and straightening an input wire;

two articulated robotic arms having approximately the same size and the same shape, each robotic arm including a plurality of pivotable links;

two railing mechanisms, each positioned on one longitudinal side of the base support and each connected to one of the two articulated robotic arms for enabling linear movement of the two articulated robotic arms;

a clamping mechanism attached to one of the plurality of pivotable links for holding the input wire in place;

a bending unit located adjacent to the clamping mechanism for shaping the input wire;

a cutting mechanism for cutting the shaped wire as needed; and

a controller for controlling the operation of the system,

wherein each robotic arm is movable in a longitudinal linear direction along the base support and each robotic arm has a predetermined degree of freedom of movement.

2. The system of claim 1, wherein the plurality of pivotable links include three pivotable links.

3. The system of claim 2, wherein the three pivotable links include an effector link.

4. The system of claim 3, wherein the clamping mechanism is located on the effector link.

5. The system of claim 1, further comprising a motor for applying a rotational force to a shaft connected to one of the plurality of pivotable links for pivoting the one of the plurality of pivotable links.

6. The system of claim 5, further comprising a plurality of pulleys, at least one of which is connected to the one of the plurality of pivotable links, the pulleys being connected via a belt for pivoting one or more of the plurality of pivotable links.

7. The system of claim 1, wherein the clamping mechanism includes a stationary unit and a movable unit.

8. The system of claim 7, further comprising a motor for moving the movable unit when needed.

9. The system of claim 1, wherein the clamping mechanism is configured to clamp and hold the input wire along the longitudinal axis of the system when the wire enters the system through the straightening mechanism.

10. The system of claim 1, wherein the clamping mechanism is configured to pick up the input wire from a first designated location and drop off the shaped wire to a second designated location.

11. The system of claim 1, further comprising two movable platforms, each attached to one longitudinal side of the base support and each carrying one of the two robotic arms on one of the two railing mechanisms.

12. The system of claim 1, wherein the cutting mechanism comprises:

a cutting die for holding the input wire;

a cutting arm for cutting the input wire; and

a motor for controlling the movement of the cutting arm.

13. The system of claim 12, wherein the base support includes an opening through which the cutting arm can pass.

14. The system of claim 13, further comprising a shaft connected on one side to the motor and on the other side to a flywheel, the flywheel being attached to the cutting arm.

15. The system of claim 1, further comprising a control panel, the control panel comprising the controller, a motor driver, a memory, one or more power ports and one or more communications ports.

16. The system of claim 15, wherein the system can be connected to a computing device via at least one of the communications ports.

17. The system of claim 16, wherein a program to control the operation of the system may be transferred to the control panel from the computing device via the at least one communication port.

18. The system of claim 17, the program controls an operation of at least one of the two articulated robotic arms, the clamping mechanism, the bending unit, and the cutting mechanism.

19. The system of claim 15, wherein at least one of the power ports is for providing power to the system.

20. The system of claim 1, wherein the bending mechanism is configured to shape the input wire on two sides of the clamping mechanism and in both clockwise direction and counterclockwise directions.