Method and apparatus for separating a blank

Abstract

The present application relates to a method for separating blanks, having the following steps: continuous conveying of a metal strip (2) in a conveying direction (T) to a laser cutting station; cutting of the metal strip (2) by means of at least one cutting laser, the cut metal strip (2) being formed from successive sections (AT) having the same cutting geometry, each section (AT) comprising at least one blank (P) and at least one residual blank (RP) adjacent to the blank (P); conveying of the cut metal strip (2) in the conveying direction (T) by means of a first conveyor belt (4); conveying of the cut metal strip (2) from the first conveyor belt (4) by means of a suction conveyor which is operated using negative pressure; suspended conveying of the cut metal strip (2) in the conveying direction (T) using the suction conveyor (5); separate discharge of the at least one residual blank (RP) in each section (AT) by means of a first interruption of the negative pressure in predefined regions of the suction conveyor (5); conveying of the at least one blank (P) in each section (RP) to a position overlapping a second conveyor belt (6) and discharge of the at least one blank (P) from the suction conveyor (5) by means of a second interruption of the negative pressure; conveying of the blanks (P) discharged one after the other in the conveying direction (T) by means of the suction conveyor (5) to a collection station.

Description

TECHNICAL FIELD

[0001] The present application relates to a method and a device for separating blanks. BACKGROUND

[0002] US 2016 / 0318126 A1 discloses a method and a device for separating blanks. A metal strip is continuously conveyed in a conveying direction to a laser cutting station. At the laser cutting station, the metal strip is continuously cut by at least one cutting laser, thereby forming a cut metal strip comprising blanks and residual blanks adjacent to the blanks. The cut metal strip is conveyed downstream of the laser cutting station in the conveying direction using a first conveyor belt. Then, a robot picks up the blanks from the first conveyor belt and conveys them to a collection station, for example a stacker.

[0003] In order for the robot to pick up the blanks, a specific suction tool adapted to the geometry of the respective blank has to be installed at the end of the robot arm. If the geometry of the blanks changes, the suction tool has to be adjusted accordingly or a different suction tool has to be connected to the end of the robot arm. This is not only time-consuming but also expensive.

[0004] In order to achieve as high a yield of blanks as possible, the metal strip is usually conveyed quickly through the laser cutting station, so that multiple robots are required to pick up the blanks. This further increases the expenditure and the space requirement of the existing devices.

[0005] WO 2009 / 105608 A1 discloses a method of cutting blanks. In this method, a metal strip is continuously conveyed in a conveying direction through two laser cutting stations. The first laser cutting station is located at the inlet of a first conveyor device and the second laser cutting station is located at the outlet of a second conveyor device, through which the metal strip is cut into blanks by the laser cutting stations. The blanks are then transported away in the conveying direction.

[0006] DE 1282556 discloses a device for selectively conveying and stacking blanks continuously fed at a distance. Depending on the measured thickness, the blanks are fed to different stacking positions. The existing device is only suitable for the selective conveying and stacking of blanks having a uniform predetermined geometry.

[0007] It is an object of the present application to overcome the disadvantages of the prior art. In particular, a method and a device shall be provided with which blanks can be separated from adjacent residual blanks and from each other with reduced effort and with which the production rate of blanks can be increased, according to another object of the present application. SUMMARY

[0008] The object of the present application is achieved by a method for separating blanks and a device for separating blanks.

[0009] The method for separating blanks according to the application comprises the following steps:

[0010] continuously conveying a metal strip in a conveying direction to a laser cutting station;

[0011] simultaneously cutting the metal strip by means of at least one cutting laser, the cut metal strip being formed from successive sections having the same cutting geometry, each section comprising at least one blank and at least one scrap piece adjacent to the blank;

[0012] conveying the cut metal strip in the conveying direction by means of a first conveyor belt;

[0013] conveying the cut metal strip from the first conveyor belt by means of a suction conveyor operated by means of negative pressure;

[0014] suspendedly conveying the cut metal strip in the conveying direction using the suction conveyor;

[0015] expelling the at least one scrap piece in each section separately by means of a first interruption of the negative pressure in the predefined area of the suction conveyor;

[0016] conveying the at least one blank in each section to a position overlapping the second conveyor belt and expelling the at least one blank from the suction conveyor by means of a second interruption of the negative pressure; and conveying the blanks expelled successively in the conveying direction by means of the suction conveyor to a collection station.

[0017] The metal strip is repeatedly cut into sections having a predefined length extending in the conveying direction. The specified length is also referred to as "pitch length".

[0018] Each section has the same cutting geometry. That is to say, in each section, the geometry of the cut forms a pattern which is repeated in the same or almost the same way in the next section.

[0019] In one section, at least one blank and a scrap piece adjacent to the blank are formed by at least one cut. The at least one blank and the at least one scrap piece usually have different geometrical shapes from one another. The at least one blank formed from each section forms a so-called "finished part", whereas the scrap piece is discarded as waste.

[0020] By means of the application, it is advantageously possible to separate a blank from at least one scrap piece in one section without great technical effort.

[0021] Unlike existing technologies, the suction conveyor suspends and conveys blanks and at least one scrap blank or cut metal strip from the first conveyor belt along the conveying direction. During the suspension conveying of the blanks, only the scrap blank is discharged from the suction conveyor. The blanks are first suspended and conveyed at a position overlapping with the second conveyor belt, and then discharged from the suction conveyor onto the second conveyor belt by a second interruption of negative pressure.

[0022] There is no longer a need for robots equipped with suction tools suitable for the blank geometry to separate blanks. The suction conveying device proposed in this application allows blanks of any geometry to be discharged without altering its design. Advantageously, the suction conveying device can operate at the same conveying speed as the first conveyor belt. For example, if the conveying speed of the first conveyor belt is increased to improve the yield of blanks with simple geometries, the conveying speed of the suction conveying device can be adapted accordingly without further adjustment.

[0023] EP1355838B1 discloses a suitable suction conveying device. In this known suction conveying device, a negative pressure channel is provided between two parallel conveyor belts. A metal sheet is placed on the conveyor belts, and according to the Venturi principle, a dynamic negative pressure is formed in the negative pressure channel, thereby pulling the metal sheet onto the conveyor belts.

[0024] To implement the method according to this application, it is advantageous to use a plurality of suction conveyors arranged adjacent to each other in a y-direction extending perpendicular to the conveying direction. The distance between the suction conveyors can vary in the y-direction, thus allowing the suction conveyors to adapt to the geometry of the blank or scrap.

[0025] According to an advantageous embodiment, the suction conveying device has a plurality of compressed air impact devices for interrupting negative pressure, which are continuously arranged along the conveying direction and in a y-direction perpendicular to the conveying direction. Each compressed air impact device can be selectively connected to an air compression source via a separate controllable valve to generate a compressed air impact. Therefore, the suction conveying device has a two-dimensional array of compressed air impact devices, which can be selectively and individually controlled to discharge at least one blank according to a predetermined geometry.

[0026] Advantageously, the negative pressure is interrupted by a compressed air impact generated by a compressed air impact device. Therefore, advantageously, the device for generating the negative pressure can operate continuously and be used to supply air to other areas of the suction and conveying device.

[0027] According to another advantageous embodiment, in a CAM system built for producing blanks, a specific compressed air impact device is selected based on the geometry of at least one residual blank and the information is sent to a controller. For example, in the CAM system, at least one residual blank and / or at least one blank can be marked. Then, an appropriate computer program is used to select the compressed air impact device corresponding to the discharge of the respective residual blank. Information from the selected compressed air impact device is transmitted to the control system or controller. This makes the programming of the blank separation process quick and simple.

[0028] Advantageously, a compressed air impact is generated by controlling a selected compressed air impact device for discharging at least one blank, according to the conveying path of the metal strip. That is, the control system precisely controls the selected compressed air impact device to generate compressed air impact when the metal strip covers a specific conveying path in the conveying direction. Advantageously, the dimensions of the conveying path are designed such that the blank to be discharged is located exactly opposite the compressed air impact device of the suction conveyor. The blank is discharged from the suction conveyor by interrupting the negative pressure through activation of the compressed air impact device.

[0029] Advantageously, the scrap is discharged into a scrap removal device located between the first and second conveyor belts. In the scrap removal device, the scrap is appropriately crushed by a crushing device. The crushed scrap can then be conveyed to a waste container via a conveyor belt.

[0030] According to a particularly advantageous embodiment of this application, the first conveying speed of the first conveyor belt and the suction conveying device is lower than the second conveying speed of the second conveyor belt. That is, the blanks received by the second conveyor belt are accelerated. Therefore, the distance between blanks placed one after another on the second conveyor belt is greater than the distance between the cut metal strips. This simplifies the handling of blanks, such as mobile phones and stacking.

[0031] Conveniently, the blanks are stacked at a collection station located downstream of the second conveyor belt. The collection station may also include multiple stackers that alternately load blanks.

[0032] According to another aspect of this application, an apparatus for separating blanks is provided, comprising: a conveying device for continuously conveying a metal strip to a laser cutting station along a conveying direction; a laser cutting station having at least one cutting laser for simultaneously cutting the metal strip such that continuous segments having the same cutting geometry form a cut metal strip, each segment comprising at least one blank and at least one residual blank adjacent to the blank; and a first conveyor belt for conveying the cut metal strip downstream of the laser cutting station along the conveying direction.

[0033] A suction conveying device operating under negative pressure is used to receive cut metal strips from a first conveyor belt and to convey the cut metal strips in the air along the conveying direction; a compressed air impact device is used to discharge at least one residual blank from each segment by first interrupting the negative pressure in a predetermined area of ​​the suction conveying device.

[0034] The second conveyor belt, which is arranged to partially overlap with the suction conveyor, is used to receive at least one blank discharged from the suction conveyor by a second interruption of negative pressure, and to horizontally transport the continuously discharged blanks to the collection station along the conveying direction.

[0035] For example, the conveying device may be a roller straightener and / or a pair of oppositely arranged conveying rollers. According to the prior art, laser cutting stations with at least one cutting laser for simultaneously cutting metal sheets and strips are generally known. For example, refer to DE102010042067A1 and WO2009 / 105608A1.

[0036] For the design of the suction conveying device, please refer to the above description. Multiple adjacent conveying devices can be arranged in the y-direction, as known for example from EP1335838B1. According to this application, an improvement has been made to the existing conveying device, which has multiple compressed air impact devices arranged adjacently along the conveying direction. By arranging multiple adjacent conveying devices in the y-direction, a set of compressed air impact devices extending in both the conveying and y-directions is obtained. Therefore, the compressed air impact devices form a two-dimensional array. For the discharge of the blank, the portion of the array overlapping with the corresponding blank can be controlled to generate compressed air impact.

[0037] For other implementations of the device, these features also constitute the features of the device, referring to the description of the method features above. Attached Figure Description

[0038] The embodiments of this application will be described in more detail below with reference to the accompanying drawings. Among them,

[0039] Figure 1 It is a block diagram of a device;

[0040] Figure 2 This is a 3D view of the suction and conveying device;

[0041] Figure 3 It is based on Figure 2 A sectional view;

[0042] Figure 4 It is based on Figure 2 Top view;

[0043] Figure 5 It is based on Figure 3 Detailed view;

[0044] Figure 6 It is based on Figure 5 Detailed view.

[0045] Figure 7 This is a first sectional view of an air compression device;

[0046] Figure 8 It is based on Figure 7 A sectional view along section line aa;

[0047] Figure 9 A metal strip with a first cut profile is shown;

[0048] Figure 10 A metal strip with a second cut profile is shown. Detailed Implementation Plan

[0049] Figure 1 A block diagram of an apparatus for separating blanks is shown. Reference numeral 1 indicates a conveying device, such as a roller straightener. Reference numeral 2 indicates a metal strip being conveyed to a laser cutting station 3. At the laser cutting station 3, the metal strip is cut into blanks P and adjacent scraps RP. The cut metal strip 2 is conveyed along the conveying direction T by a first conveyor belt 4, which is positioned downstream of the laser cutting station 3.

[0050] Reference numeral 5 indicates a suction conveying device located downstream of the first conveyor belt 4. The suction conveying device 5 picks up the blank P and the residual blank RP and suspends and conveys them along the conveying direction T.

[0051] Reference numeral 6 in the attached diagram indicates a second conveyor belt located downstream of the suction conveyor 5. The second conveyor belt 6 transports the separated billets P to the downstream collection station 7. The remaining billets RP are then processed by the crushing device (…). Figure 1 (Not shown) It is crushed and discharged as waste S.

[0052] Figures 2 to 5 The arrangement of the first conveyor belt 4, the suction conveying device 5, and the second conveyor belt 6 is shown in detail. The suction conveying device 5 includes a plurality of adjacent suction conveyors 7a arranged along the y-direction. Figure 3 and Figure 5 Both are shown as cross-sectional views through one of the suction delivery devices 7a.

[0053] Each suction conveyor 7a has two parallel conveyor belts 8, with a negative pressure channel 9 between them. Multiple suction pipes 10 extend sequentially from the negative pressure channel 9 along the conveying direction; as shown in the figure, the suction pipes 10 can be branch pipes. The end of the suction pipe 10 opposite to the negative pressure channel 9 is located in the suction channel 11 (see reference). Figure 7 and Figure 8 ).

[0054] In particular, from Figure 5 As can be seen, the suction conveyor 5 is arranged such that the first section A1 is substantially located between the first conveyor belt 4 and the second conveyor belt 6. The second section A2 of the suction conveyor 5 extends downstream of the first section A1 and partially covers the second conveyor belt 6.

[0055] In the first section A1, the number of suction pipes 10 per unit length set in the conveying direction T is greater than the number set in the second section A2.

[0056] Specifically, from Figure 7 and Figure 8 As can be seen, compressed air line 11a is connected to each suction line 10, and compressed air line 11a is connected to an air compression source (not shown in the figure). Each compressed air line 11a is connected to a valve (not shown in the figure), so that compressed air can be selectively and individually supplied to each suction line 10.

[0057] exist Figure 2 and Figure 3 In the accompanying drawings, reference numeral 12 indicates a crushing device disposed at the end of the sliding surface 13. The sliding surface 13 extends downward from the downstream end of the first conveyor belt 4 toward the crushing device 12.

[0058] Figure 9 A top view of the first cut profile of the metal strip 2 in the CAM system is shown. A small residual blank RP is present in the blank P here.

[0059] Figure 10 The second cut profile of the metal sheet / strip 2 is shown. Here, there is a relatively large residual blank RP in the blank P.

[0060] The device has the following functions.

[0061] First, manually label M1 and M2 using a CAM system (see reference). Figure 10 This determines which sections of the cut metal strip 2 are the scrap RP that need to be discharged. For this purpose, for example, a cross is set as the first mark M1 for the scrap RP. On the other hand, the blank P is marked with a second mark M2, for example, in... Figure 10 In the middle, the second mark M2 is a circle.

[0062] If the residual blank RP is small (reference) Figure 9 If the blank is not marked, then no marking is performed. In this case, the blank RP will not adhere to the suction conveyor 7a, but will be directly conveyed from the first conveyor belt 4 to the sliding surface 13 and the downstream crushing device 12.

[0063] Markers M1 and M2 are processed by the CAM system. Specifically, this system calculates which air compressor will be controlled to discharge the corresponding blank RP. This information is then transmitted to the machine control system.

[0064] The metal strip 2 passes through the laser cutting station 3 and is cut at the laser cutting station 3, resulting in continuous segments AT with substantially the same cutting geometry at the exit of the laser cutting station 3. Each segment AT has a predetermined length L or pitch length in the conveying direction T. Each segment AT includes at least one blank P and at least one residual blank RP adjacent to the blank P (reference). Figure 9 The cut metal strip 2 is conveyed along the conveying direction T by the first conveyor belt 4. Then, the suction conveyor 5 receives the cut metal strip 2 and further conveys it along the conveying direction T. After the cut metal strip 2 is received, the small blanks RP immediately fall onto the sliding surface 13.

[0065] In the first section A1, the suction conveying device 5 has an array of compressed air impact devices extending along the conveying directions T and Y. Each compressed air impact device includes a suction line 10 and a compressed air line 11a connected to the suction line 10, which can be selectively opened and closed by a valve (not shown). Once the blank RP completely overlaps with the first section A1, the control system activates the compressed air impact devices that overlap with the blank RP. The compressed air impact devices generate compressed air impacts. As a result, the negative pressure in this area disappears, and the blank RP falls onto the sliding surface 13. Under the action of gravity, the blank RP slides into the crushing device 12 and is crushed, and the resulting waste S is discharged.

[0066] On the other hand, the blank P is suspended and conveyed from the first section A1 of the suction conveyor 5 to the second section A2. Once the blank P is fully overlapped with the second conveyor belt 6, the compressed air impact device in the second section A2 is activated by the control system, thereby discharging the blank P onto the second conveyor belt 6.

[0067] The first conveyor belt 4 and the conveyor belt 8 of the suction conveyor 5 operate at the same rotational speed. Advantageously, the second conveyor belt 6 operates at a greater rotational speed than the first conveyor belt 4. Therefore, the blanks P discharged from the suction conveyor 5 onto the second conveyor belt 6 are accelerated. They are discharged a greater distance on the second conveyor belt 6 than they are conveyed to the suction conveyor 5, which is beneficial for the handling of the blanks P, especially for conveying them to stackers, etc.

[0068] Figure label:

[0069] 1 Conveying device

[0070] 2 Metal strip

[0071] 3 Laser Cutting Station

[0072] 4 First Conveyor Belt

[0073] 5. Suction and Conveying Device

[0074] 6 Second Conveyor Belt

[0075] 7. Collection station;

[0076] 7a Suction Conveyor

[0077] 8 Conveyor Belt

[0078] 9 Negative Pressure Channels

[0079] 10 Suction Tubing

[0080] 11. Intake pipe

[0081] 11a Compressed Air Piping

[0082] 12 Crushing device

[0083] 13 Sliding surfaces

[0084] A1 Section 1

[0085] A2 Second Section

[0086] AT section

[0087] L length

[0088] M1 First Mark

[0089] M2 Second Marker

[0090] P blank

[0091] RP blank

[0092] S waste

[0093] T conveying direction

Claims

1. A method for separating blanks, characterized in that, Includes the following steps: The metal strip (2) is continuously conveyed to the laser cutting station (3) along the conveying direction (T); The metal strip (2) is cut simultaneously by at least one cutting laser. The cut metal strip (2) is formed by continuous segments (AT) with the same cutting geometry. Each segment (AT) includes at least one blank (P) and at least one residual blank (RP) adjacent to the blank (P). The cut metal strip (2) is conveyed along the conveying direction (T) by the first conveyor belt (4); The cut metal strip (2) from the first conveyor belt (4) is conveyed by a suction conveyor (5) operating under negative pressure; The cut metal strip (2) is suspended and conveyed along the conveying direction (T) using a suction conveying device (5); At least one blank (RP) in each section (AT) is discharged by first interrupting the negative pressure in the predetermined area of ​​the suction conveying device (5); At least one blank (P) in each section (AT) is conveyed to a position overlapping with the second conveyor belt (6), and at least one blank (P) is discharged from the suction conveyor (5) by a second interruption of the negative pressure; and, The blanks (P) that are successively discharged by the suction conveying device (5) along the conveying direction (T) are conveyed to the collection station (7).

2. The method for separating blanks according to claim 1, characterized in that: The suction and conveying device (5) has a plurality of compressed air impact devices (11, 11a) for interrupting negative pressure, the compressed air impact devices (11, 11a) being arranged continuously along the conveying direction (T) and in the y direction perpendicular to the conveying direction (T); wherein each compressed air impact device (11, 11a) can be selectively connected to an air compression source through a separate controllable valve to generate compressed air impact.

3. The method for separating blanks according to claim 2, characterized in that: The negative pressure is interrupted by at least one compressed air shock wave generated by the compressed air impact device (11, 11a).

4. The method for separating blanks according to claim 3, characterized in that: In the CAM system built for producing the blank (P), a specific compressed air impact device (11, 11a) is selected based on the geometry of at least one blank (RP) and sent to the controller.

5. The method for separating blanks according to claim 4, characterized in that: According to the conveying path of the metal strip (2), the selected compressed air impact device (11, 11a) for discharging at least one blank (RP) is controlled by the control system to generate compressed air impact.

6. The method for separating blanks according to any one of claims 1 to 5, characterized in that: The blank (RP) is discharged into a blank removal device located between the first conveyor belt (4) and the second conveyor belt (6).

7. The method for separating blanks according to claim 6, characterized in that: The blank (RP) is crushed in the blank removal device.

8. The method for separating blanks according to claim 7, characterized in that: The first conveying speed of the first conveyor belt (4) and the suction conveying device (5) is lower than the second conveying speed of the second conveyor belt (6).

9. The method for separating blanks according to any one of claims 1 to 5, characterized in that: The blanks (P) are stacked in the collection station (7).

10. An apparatus for separating blanks, characterized in that, include: A conveying device (1) is used to continuously convey metal strips (2) to the laser cutting station (3) along the conveying direction (T); A laser cutting station (3) having at least one cutting laser for simultaneously cutting the metal strip (2) so that continuous segments (AT) having the same cutting geometry are formed into the cut metal strip (2), each segment (AT) including at least one blank (P) and at least one stub (RP) adjacent to the blank (P). The first conveyor belt (4) is used to convey the cut metal strip (2) downstream of the laser cutting station (3) along the conveying direction (T); A suction conveying device (5) operating under negative pressure is used to receive the cut metal strip (2) from the first conveyor belt (4) and to convey the cut metal strip (2) in the air along the conveying direction (T). Compressed air impact device (11, 11a) discharges at least one blank (RP) from each segment (AT) by first interrupting the negative pressure in a predetermined area of ​​the suction conveying device (5). A second conveyor belt (6), which is arranged to partially overlap with the suction conveyor (5), is used to receive at least one blank (P) discharged from the suction conveyor (5) by a second interruption of negative pressure, and to horizontally transport the continuously discharged blanks (P) along the conveying direction (T) to the collection station (7).

11. The device according to claim 10, characterized in that: The suction and conveying device (5) has multiple compressed air impact devices (11, 11a) arranged continuously along the conveying direction (T) and in the y direction perpendicular to the conveying direction (T); each compressed air impact device (11, 11a) can be selectively connected to an air compression source through a separate controllable valve to generate compressed air impact.

12. The device according to claim 10 or 11, characterized in that, The CAM system for producing blanks (P) is set up in such a way that, based on the geometry of at least one blank (RP), a specific compressed air impact device (11, 11a) is selected and sent to the controller.

13. The device according to claim 12, characterized in that, The controller is arranged such that: according to the conveying direction (T) of the metal strip (2), the selected compressed air impact device (11, 11a) for discharging at least one blank (RP) is controlled to generate compressed air impact.

14. The apparatus for separating blanks according to claim 10 or 11, characterized in that, A blank removal device for receiving waste blanks (RP) is provided between the first conveyor belt (4) and the second conveyor belt (6).

15. The device according to claim 14, characterized in that, The slab removal device includes a device for crushing slabs (RP).

16. The device according to claim 10 or 11, characterized in that, The first conveying speed of the first conveyor belt (4) and the suction conveying device (5) is lower than the second conveying speed of the second conveyor belt (6).

17. The device according to claim 10 or 11, characterized in that, Downstream of the second conveyor belt (6) is provided at least one stacking device for collecting blanks (P).

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