WIRE BENDING MACHINE COMBINING A SEQUENTIAL SHAPING DEVICE AND A DEVICE USING A TOOL PLATE

Abstract

The invention concerns a machine for automatically shaping components via different types of bending provided in a common plane or different planes. The machine includes a first device for performing a sequential shaping with standard tools by individual bending, and a second device using a tool plate. Both devices are managed by a single digital control. The method for controlling such a machine is characterized in that digital control provides the possibility for producing a blank of a component by individual bending on the first device followed by transfer of the component on the second device for finishing the component. Digital control provides the possibility of shaping one part of the component on the first device and shaping the remaining parts on the second device. The digital control also provides the possibility of using each machine alone and the possibility of using both machines for producing the same component.

Description

CROSS-REFERENCE TO RELATED U.S. APPLICATIONS

Not applicable.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not applicable.

NAMES OF PARTIES TO A JOINT RESEARCH AGREEMENT

Not applicable.

REFERENCE TO AN APPENDIX SUBMITTED ON COMPACT DISC

Not applicable.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a new wire bending machine and to the methods of controlling such a machine.

2. Description of Related Art Including Information Disclosed Under 37 CFR 1.97 and 37 CFR 1.98

At the present time, there are two main types of wire bending machine.

A first type of machine operates sequentially, bend by bend, using simple and economical standard tooling, for example tools known as “turntables”, possibly also including a device for rotating the wire so that bends can be made in different planes.

This type of machine is perfectly adequate for shaping short production runs of components, both in terms of the quality of the shaping and in terms of the profitability and unit cost.

By way of example, patent application EP 0 865 842 describes a sequential shaping machine with two bending heads, it being impossible for these two heads to operate simultaneously on the same workpiece, it still being necessary to employ a transfer by gripper in order to change head and perform flat shaping. This machine has the abovementioned disadvantages namely that it is adequate only for production runs at low production rates. Furthermore, a sequential shaping machine requires a control method capable of programming a geometry.

A second type of automatic bending machine allows a workpiece with several bends to be shaped on a tool plate the tools of which are actuated concurrently so as to increase productivity and operate at a high production rate.

A machine such as this is numerically controlled and is described in European Patent EP 0 301 972.

More specifically, this relates to a wire bending machine and to the method of controlling it, which is a method suited to programming the movements of the actuators.

On account of its cost, a machine such as this is suitable only for shaping components in long production runs.

The abovementioned machines do not display optimum profitability when shaping medium production runs of components because the sequential machine operates at too low a production rate, and the machine with a tool plate represents too great an investment. In both instances, this results in a unit cost that is not optimized for medium production runs.

By way of an illustration of the production problems encountered, if a production requires a production rate of a few components per minute, for example of 2 to 3 components per minute, the industrialist will preferably procure a machine of the sequential type, and if the production of a similar component requires a high production rate for example of 30 to 60 components per minute, a machine with a tool table will be procured. By contrast, if a component needs to be produced at an intermediate production rate of, for example, 10 to 12 components per minute, or even of 8 to 30 components per minute, the prior art has no machine to offer that will suit this need at optimum cost.

There does not currently exist any machine capable of reducing the unit cost when producing medium production runs, and it is thus an objective of the present invention to provide a solution to this problem.

BRIEF SUMMARY OF THE INVENTION

The invention consists in a machine for automatically shaping components using various bending operations performed in one and the same plane or in different planes, characterized in that it comprises, in combination, a first device for carrying out sequential shaping bend by bend using standard tools, and a second device employing the tool plate, the two devices being operated using a single numerical control device capable of programming both geometry and actuator movements for a medium production rate.

This really is a combination of two machines because, firstly, the two shaping techniques have always been poles apart, as the programming methods differ from one to the other, one being based on numerical control of the geometry of a component, while the other is based on electromechanical parameterizing of cams, and because, secondly, production can be optimized when shaping medium production runs, something that was impossible in the prior art, and because, finally, it is possible to omit the need for an actuating arm for changing heads in the case of flat shaping.

Preferred embodiments of the machine are characterized in that the first device comprises at least one turntable, and/or in that it further comprises at least one rotary clamp, and/or that the tool plate can be mounted and actuated in a different plane from the shaping plane of the first device, and further comprises a transfer device suited to the change in plane.

Further, the control method according to the invention is characterized in that the numerical control device provides the option of creating a part-finished component bend by bend on the first device then of transferring the component to the second device in order to complete the component, and/or the numerical control device provides the option of shaping part of the component using the first device and of shaping the remaining part or parts on the second device, and/or the numerical control device provides the option of using each machine on its own and/or the numerical control device provides the option of employing the two machines in order to create the same component.

The invention will be better understood with the aid of the attached FIGS. 1 and 2 which schematically depict a front view and a view in section along line A-A, of a machine according to an non-limiting alternative form of embodiment of the invention.

A reminder of the principle of a numerical machine according to European Patent EP 0 301 972 and of its method of operation is also given using the attached FIGS. 3 and 4.

The machine depicted in the figures is a combination of a sequential shaping machine (1) and of a table shaping machine equipped with a tool plate (2), as described in the Patent EP 0 301 972 mentioned in the introduction.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 is a schematic view of the wire bending machine of the present invention.

FIG. 2 is a cross-sectional view of the wire bending machine of the present invention across line A-A of FIG. 1.

FIG. 3 is partial perspective view of the tool plate of the present invention.

FIG. 4 is a partial cross-sectional view of the operation of the tool plate in the machine of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

In the example of FIGS. 1 to 2, the sequential machine (1) has standard tools, for example turntables (3, 4) able to move on two axes (x) and (y) to create bends in a plane (x,y), and possibly a rotary clamp (5) when the profile of the component entails bending in a direction that is angled with respect to the plane (x,y).

In the alternative form of FIGS. 1 to 2, the second machine has a table (6) equipped with a tool plate (7), each tool being able to be moved autonomously and being mechanically driven by systems involving through-bolts such as (8) and which are not depicted in detail in these figures, each one being controlled by a predetermined program of a numerical control device (9).

As explained in the abovementioned patent, this collection of tools is capable of creating complex components and/or of creating components at a high production rate.

In the alternative form of embodiment depicted in the figures, the tool plate (7) is positioned in the working plane (x,y) of the first machine and the same wire feed device is able to transfer the wire directly from the first to the second machine, and in this case a transfer means can therefore be omitted.

One and the same numerical control device operates the tools of both machines, and is therefore capable of programming both the geometry and the actuators of the plate, thus allowing the programming steps to be combined with one another.

According to another alternative form of embodiment that has not been depicted, provision may be made for the shaping planes of the two machines to be offset from one another in a horizontal direction (z), and where this is done, an arm or some other means needs to be provided in order to transfer the component from the shaping plane (x,y) of the first machine to the shaping plane of the tool table (7).

Combining the two machines therefore has the advantage of making it easier to transfer components and of synchronizing the movements of the tools of the two machines, this synchronization being essential for reducing costs and optimizing manufacture and to allow a single shaping production rate on both machines when the shaping steps are spread across the two machines.

A component may be shaped according to various combinations of programming which are chosen according to the complexity of the profile to be obtained, according to the investment in special-purpose tooling, or according to the desired production rate:

1) It is, for example, possible to create a part-finished component bend by bend on the first machine (1) then to transfer the component and perform the complex operations and/or to operate at a high production rate, on the second machine so as to complete the component. This technique is particularly applicable to complex shapes (for example where there are tricky changes in plane, or where closed loops are to be created). Creating a part-finished component on the first machine makes it possible to reduce the complexity of the tooling of the second machine and therefore the overall unit cost.

2) It is equally conceivable for part of the component to be shaped on the first machine (1) and for the remaining part or parts to be finalized on the second machine (2).

3) It is also possible to use each machine on its own as need be. For example, for creating prototypes, only the first machine is used or, for creating certain components immediately as long production runs, the second machine will prove to be the more appropriate one.

4) A solution employing the two machines for creating one and the same component may also be conceived of under the following circumstances: where there is a gradual ramp-up in production rates, where a number of components are being produced that have a common part (produced on the tool plate) and a specific part (produced on the turntable for example), or for components the design of part of which is not completely set or where there are evolutions to a component initially scheduled to be produced on the tool plate.

Thus, a machine according to the invention displays great flexibility of use and is able to respond to all industry requirements for the shaping of wire with the best possible cost/production rate and/or cost/shaping complexity optimization, even for medium production runs, something that could not be achieved previously.

Using these techniques, the component may be parted off after the first shaping operation, after transfer between the two machines or after the second shaping operation; a first shaping operation on the first machine may be performed on one component while the final shaping of the previous component is being performed on the second machine, thus increasing productivity.

All these shaping operations are rendered possible because the machines are controlled together, they therefore work together to allow shaping programs that were not possible when each machine was operating separately as in the prior art, making it possible to program a single shaping production rate for the two machines when the shaping steps are spread across the two machines.

The principle of operation of a machine with a tool plate and the way in which it is controlled are recalled here with reference to FIGS. 3 and 4.

A machine of this type comprises active means, a work plate, a tool plate, through-bolts and tools, of which the active means, which are autonomous, independent, and secured to the tool plate, actuate levers connected by through-bolts to the tools mounted on the tool plate, the active means being mounted on a common translation means via a disengageable means, said active means (60,61,62,63) being moved by brushless electric motors (70) via ball screws, and the actuating levers (50,51,52,53) that actuate tools (21,22,23,24,25) being connected to the through-bolts (30,31,32,33) by connections (40,41,42,43) via one of their ends (513) and being connected to the translation means via their other end (511).

As a preference, a machine of this type is characterized in that the common translation means (45) of translating the active means (60,61,62,63) is a rotating screw (45) driven by a motor (90), the disengageable means being half-nuts in mesh with this same screw.

As a preference, a machine of this type is characterized in that the active means (60,61,62,63), when in the disengaged position, are fixed to the work plate (1).

Furthermore, the method of controlling it is characterized in that, having studied the movements of the tools, the coordinates of the link points are entered, the characteristics of the active means (60,61,62,63) are stored in memory, and in that the processing unit calculates the theoretical motor start points so that the tools will operate concurrently.

As a preference, said method takes account of the inertia of the system when determining the actual start points.

Furthermore, as a preference, the processing unit calculates how the link points move when the characteristics of the active means (60,61,62,63) and/or one of the values of the coordinates of the link points is or are modified.

Finally, as a preference, the feed starts and feed ends coincide with the starts and ends of cycles.

A person skilled in the art will be readily able to refer to the corresponding description in order to reacquaint himself with the workings of this type of tool plate machine.

Claims

1. A machine for automatically shaping components using various bending operations performed in at least one plane, said machine comprising: a first means for carrying out sequential shaping bend by bend using standard tools;a second for carrying out sequential shaping bend by bend using a tool plate; anda single numerical control means for both the first and second means, producing components at a production rate of 8 to 30 components per minute.

2. The machine as claimed in claim 2, wherein the first means comprises at least one turntable.

3. The machine as claimed in claim 2, wherein the first means further comprises at least one rotary clamp.

4. The machine as claimed in claim 1, wherein said tool plate is mounted and actuated in a different plane from a shaping plane of the first means, further comprising: a transfer device suited to a change in plane from the first means to the second means.

5. The machine as claimed in claim 1, wherein the second means comprises an active means, a work plate, said tool plate, through-bolts and tools, the active means being autonomous, independent, and secured to the tool plate, said through-bolts connecting actuate levers to the tools mounted on the tool plate, the active means being mounted on a common translation means via a disengageable means, said active means having brushless electric motors being moveable via ball screws, the actuating levers being connected to the through-bolts by connections via one end thereof and being connected to the translation means via an opposite end thereof.

6. The machine as claimed in claim 5, wherein the common translation means is a rotating screw driven by a motor, the disengageable means being half-nuts in mesh with said rotating screw.

7. The machine as claimed in claim 5, wherein the active means, when in a disengaged position, are fixed to the work plate.

8. A method of controlling a machine as claimed in claim 1, the method comprising the steps of: synchronizing the first and second means by the numerical control device.

9. The method of controlling a machine as claimed in claim 8, further comprising the step of: providing an option of creating a part-finished component bend by bend on the first device and then transferring a component to the second means in order to complete the component.

10. The method of controlling the machine as claimed in claim 8, further comprising the step of: providing an option of shaping part of the component using the first means and shaping the remaining part or parts on the second means.

11. The method of controlling the machine as claimed in claim 8, further comprising the step of: providing an option of using the first means or the second means independently.

12. The method of controlling a machine as claimed in claim 8, further comprising the step of: providing an option of employing the first means and the second means for a single component.