Dynamic clamping device and method for laser heating forming of plate

Abstract

The present application relates to the field of machining, and discloses a dynamic clamping device and method for laser heating forming of plate materials, the device comprising at least two groups of clamps, a sliding block and a clamp base, the two groups of clamps being a forming clamp group and a positioning clamp group respectively, the forming clamp group and the positioning clamp group being used for fixing the plate materials on the clamp base, the positioning clamp group and the forming clamp group each comprising at least one group of symmetrically arranged clamp units, each clamp unit comprising a cylinder, a clamp and a rotatable fixing block, one end of the clamp being connected with a cylinder piston rod of the cylinder, the rotatable fixing block being fixedly connected with the cylinder, the clamp being hingedly connected with the rotatable fixing block, the cylinder piston rod of the cylinder being moved up and down to move the clamp up and down to release and clamp the plate materials, and the cylinder being slidably arranged on the clamp base. The present application is different in clamping position due to different laser scanning positions, and compared with the conventional fixed-position clamping mode, the clamping method can significantly improve the laser heating bending forming precision of the metal plate materials.

Description

Technical Field

[0001] This invention relates to the field of machining, and specifically to a dynamic clamping device and method for laser heating and forming of sheet metal. Background Technology

[0002] Laser heating forming of metal sheets is a sheet bending technology that relies on the uneven internal stress induced in the sheet during laser heating to cause plastic deformation and achieve a certain amount of deformation. Experimental phenomena show that during laser heating forming, bending deformation occurs not only around the scanning line but also around the direction perpendicular to the scanning line. This results in varying deformation amounts at different positions along the scanning line after sheet forming, leading to uneven deformation and lower forming accuracy. Summary of the Invention

[0003] The present invention aims to provide a dynamic clamping device and method for laser heating forming of sheet metal, so as to make the deformation of sheet metal after laser heating forming tend to be uniform and improve the forming accuracy of sheet metal.

[0004] To achieve the above objectives, the present invention provides a dynamic clamping device for laser heating forming of sheet metal, comprising at least two sets of clamping fixtures, a slider, and a clamping base. The clamping base is used to place the sheet metal. The two sets of clamping fixtures are a forming clamping fixture set and a positioning clamping fixture set, which are used to fix the sheet metal on the clamping base. Each of the positioning clamping fixture set and the forming clamping fixture set includes at least one symmetrically arranged clamping unit. When the sheet metal is formed, the forming clamping fixture set fixes the sheet metal. After the sheet metal is formed, the positioning clamping fixture set fixes the sheet metal. Each clamping unit includes a cylinder, a clamp, and a rotatable fixing block. One end of the clamp is connected to the piston rod of the cylinder. The rotatable fixing block is fixedly connected to the cylinder. The clamp is hinged to the rotatable fixing block. When the piston rod of the cylinder moves up and down, it causes the clamp to move up and down to release and clamp the sheet metal. The cylinder is slidably disposed on the clamping base.

[0005] Preferably, as an improvement, the forming fixture group is located at a first preset distance L of the plate scanning line, the positioning fixture group is located at a second preset distance of the forming fixture group, and the forming fixture group is located between the scanning line and the positioning fixture group.

[0006] Preferably, as an improvement, it also includes a slider, with the cylinder body of the cylinder fixed on the slider. A dovetail groove is provided on the bottom of the clamp, and the slider is slidably disposed within the dovetail groove. The slider slides within the dovetail groove, and as it slides, it drives the cylinder to move, thereby changing the position of the clamp on the sheet metal. The slider facilitates the movement of the cylinder while avoiding direct contact and friction between the cylinder and the clamp base, thus preventing damage to the cylinder.

[0007] Preferably, as an improvement, the fixture base is also included on a worktable, on which it is fixed. The worktable facilitates the fixing of the fixture base.

[0008] Preferably, as an improvement, the rotatable fixing block has a T-shaped structure. The rotatable fixing block has a rotatable structure that drives the clamp to rotate around the center line of the cylinder piston rod. The horizontal part of the rotatable fixing block is fixed to the cylinder, and the rotatable fixing block is hinged to the middle part of the clamp. Making the rotatable fixing block rotatable allows the clamp to rotate around the center line of the cylinder piston rod, thus making it easier for the clamp to hold the formed sheet metal.

[0009] Preferably, as an improvement, the fixture base includes L-shaped plates, which are symmetrically arranged and face outwards. The L-shaped plates are easy to place, and the spaces between them form a working space. During laser forming, the L-shaped plates can protect structures such as cylinders on their outer sides.

[0010] To achieve the above objectives, this solution also provides a dynamic clamping method for laser heating forming of sheet metal, comprising the following steps:

[0011] Step 1: Divide the two ends of the sheet into end A and end B. First, shape end A and select the first scanning line L11 on end A. Select scanning lines L12 to L1n in sequence along the center of the sheet. For end B, the scanning lines towards the center of the sheet are L21 to L2n in sequence. The fixture group closest to the shaped end is the forming fixture group, and the other fixture group is the positioning fixture group.

[0012] Step 2: When laser heating and forming the first scanning line L11, the forming fixture group fixes the plate on the fixture base, and the positioning fixture group is in standby state; after the first scanning line L11 is formed, the positioning fixture group clamps the plate, the forming fixture group is released, and the forming fixture group is moved towards the center of the plate until it is at a position of the first preset distance L from the second scanning line L12. The distance between the forming fixture group and the positioning fixture group is set to the second preset distance, and the second scanning line L12 is laser heated and formed. The above process is repeated.

[0013] Step 3: After end A of the sheet is formed, end B is formed. At this time, the forming fixture group and the positioning fixture group are changed. The forming fixture group is moved to end B and the sheet is clamped at a position at a first preset distance L from the first scanning line L21 of end B. The positioning fixture group is in standby state and the distance between the forming fixture group and the positioning fixture group is set to a second preset distance. The scanning method in step 2 is used to form end B of the sheet in sequence.

[0014] Preferably, as an improvement, the calculation method for L is as follows:

[0015] Where K = 2 is a coefficient, P is the laser power (W), d is the spot diameter (mm), and v is the scanning speed (mm / s).

[0016] Preferably, as an improvement, when forming the next scanning line, the distance between the position of the positioning fixture group that is in standby clamping the plate and the forming fixture group that clamps the plate for forming the next scanning line is 8 to 12 mm.

[0017] This invention relates to a dynamic clamping device. Actual forming results show that by using this dynamic clamping device, the shrinkage deformation along the scanning line of the sheet metal is significantly limited due to clamping the sheet metal near the forming area. This reduces the degree of deformation inconsistency after sheet metal forming, decreasing the degree of deformation inconsistency from 28.1% when using traditional fixed clamping of the sheet metal ends to 5.5%. Compared to traditional fixed clamping devices, this invention effectively improves the deformation inconsistency phenomenon after laser heating forming of sheet metal. Furthermore, by using two sets of clamping fixtures, one set of fixtures always holds the sheet metal during the forming process, preventing the sheet metal from shifting position and eliminating the need for multiple adjustments to the relative positions of the sheet metal and the laser device. Attached Figure Description

[0018] Appendix Figure 1 This is a schematic diagram of the fixture of the present invention and the method of clamping the plate.

[0019] Appendix Figure 2 This is a schematic diagram showing the distance between the clamp and the center line of the scanning line in the fixture of the present invention.

[0020] Appendix Figure 3 This is a schematic diagram illustrating the process of dynamically clamping the plate using the fixture of the present invention.

[0021] Appendix Figure 4 This is a schematic diagram of the clamping device of the present invention when clamping the next position.

[0022] Appendix Figure 5 This is a comparison diagram of the forming effect of using the clamping device of the present invention and a traditional clamping device. Detailed Implementation

[0023] The following detailed description illustrates the specific implementation method:

[0024] The reference numerals in the accompanying drawings include: 1. Cylinder piston rod; 2. Clamp; 3. Hinge mechanism; 4. Rotatable fixing block; 5. Cylinder body; 6. Plate; 7. Slider; 8. Fixture base; 9. Worktable.

[0025] The basic implementation examples are as follows: Figure 1 Appendix Figure 2 Appendix Figure 3 and attached Figure 4 As shown:

[0026] The forming plate 6 is often held by a clamp at the center line or one end of the plate 6. When the plate 6 is laser heated and formed, it will bend and deform around the direction perpendicular to the scanning line. The constraint of the clamp on the plate 6 will inhibit the bending and deformation of the plate 6 around the direction perpendicular to the scanning line. Therefore, the constraint position of the plate 6 will affect the deformation of the plate 6, and the closer the part is to the constraint position, the greater the influence tends to be.

[0027] A dynamic clamping device for laser heating forming of sheet metal includes four individual clamps, with each pair of clamps symmetrically arranged to form a clamp group, as shown in the attached figure. Figure 3 The two sets of fixtures are C1 (forming fixture set) and C2 (positioning fixture set) located near the end.

[0028] The clamp unit includes a cylinder, a clamp 2, and a rotatable fixing block 4. One end of the clamp 2 is connected to the cylinder piston rod 1 of the cylinder. In this embodiment, the clamp 2 and the cylinder piston rod 1 are specifically connected by bolts for easy disassembly and installation.

[0029] The rotatable fixing block 4 is fixedly connected to the cylinder, which can be achieved by welding. The rotatable fixing block 4 is a T-shaped block, with its horizontal part fixed to the cylinder. The T-shaped block is hinged to the middle of the clamp 2. The rotatable fixing block 4 is a rotatable structure, which can drive the clamp 2 to rotate around the center line of the cylinder piston rod, thereby expanding the clamping range of the plate.

[0030] The clamp 2 is hinged to the rotatable fixing block 4. In this embodiment, the clamp 2 and the rotatable fixing block 4 are hinged together by a hinge mechanism 3. The hinge mechanism 3 includes connecting pieces and connecting shafts. The connecting pieces are symmetrically fixed on both sides of the vertical part of the rotatable fixing block 4. The clamp 2 is located above the vertical part of the rotatable fixing block 4. The connecting shaft passes horizontally through the middle of the clamp 2, and its two ends are rotatably mounted on the corresponding connecting pieces. When the piston rod 1 of the cylinder moves up and down, it causes the clamp 2 to tilt and move up and down to release and clamp the plate 6.

[0031] It also includes a fixture base 8, which includes L-shaped plates symmetrically arranged and facing outwards. The L-shaped plates are easy to place, and the spaces between them form a working space. During laser forming, the L-shaped plates can protect structures such as cylinders on their outer sides.

[0032] The fixture base 8 is used to place the sheet 6. The forming fixture group and the positioning fixture group are used to fix the sheet 6 on the fixture base 8. Both the positioning fixture group and the forming fixture group include at least one set of symmetrically arranged fixture units. When the sheet 6 is formed, the forming fixture group fixes the sheet 6. After the sheet 6 is formed, the positioning fixture group fixes the sheet 6.

[0033] The individual fixtures in the positioning fixture group and the forming fixture group are all arranged facing each other, and the two cylinders of the individual fixtures in the positioning fixture group or the forming fixture group work simultaneously facing each other.

[0034] The cylinder is slidably mounted on the fixture base 8. In this embodiment, the cylinder is specifically slidably mounted on the fixture base 8 via a slider 7. The cylinder body 5 is fixed to the slider 7. A dovetail groove is provided on the bottom of the fixture, and the slider 7 is slidably mounted in the dovetail groove. As the slider 7 slides in the dovetail groove, it drives the cylinder to move, thereby changing the position of the clamp 2 on the plate 6. The slider 7 facilitates the movement of the cylinder and avoids direct contact and friction between the cylinder and the fixture base 8, thus preventing damage to the cylinder.

[0035] The forming fixture assembly is located at the first preset distance (L) from the scanning line of plate 6, where L is calculated using the following formula:

[0036]

[0037] Where K = 2 is a coefficient, P is the laser power (W), d is the spot diameter (mm), and v is the scanning speed (mm / s).

[0038] The positioning fixture group is located at a second preset distance from the forming fixture group. In this embodiment, the second preset distance is 8 to 12 mm, preferably 10 mm. The forming fixture group is located between the scanning line and the positioning fixture group.

[0039] It also includes a worktable 9, on which the fixture base 8 is fixed. The worktable 9 facilitates the fixing of the fixture base 8.

[0040] This solution also provides a dynamic clamping method for laser heating and forming of sheet metal, which specifically includes the following steps:

[0041] Step 1: Determine which end of the sheet material 6 should be formed first;

[0042] In this step, the laser heating forming of the sheet 6 is carried out by forming both ends separately. The two ends of the sheet 6 are divided into end A and end B. First, the end to be formed first is determined. This specific implementation takes the forming of end A as an example.

[0043] At end A, the first scanning line L11 is selected, and scanning lines L12 to L1n are selected sequentially along the center direction of the plate 6; at end B, the scanning lines towards the center of the plate 6 are L21 to L2n sequentially; the fixture group closest to the forming end is the forming fixture group, and the other fixture group is the positioning fixture group. In this embodiment, the laser device is implemented using existing devices.

[0044] Step 2: When laser heating is applied to scan line L11, fixture C1 fixes the plate 6 onto fixture base 8. The fixing position is near the center line of plate 6, and the distance from the center of scan line L11 is L (Equation 1). Fixture C2 is in standby mode. After scan line L11 is formed, fixture C2 clamps plate 6. The clamping position is determined based on the selection of the second scan line and the clamping position of fixture C1, as shown in the attached figure. Figure 4 As shown, at this time, release clamp C1 and move clamp C1 towards the center line of plate 6. Clamp plate 6 at a distance L (Formula 1) from the second scanning line L12. At this time, keep the overall distance between the two sets of clamps 10mm. Form scanning lines L13, L14...L1n in sequence according to the above forming method.

[0045] Step 31: After the first scanning line at end A is formed, determine the position of the second scanning line, and calculate the clamping position of the C1 set of fixtures when the plate 6 is formed using Equation 1. Then, use the C2 set of fixtures to fix the plate 6, ensuring that the overall distance between the two sets of fixtures is 10mm.

[0046] Step 32: After the A end of the plate 6 is formed, move the clamp 2C2 to the B end and fix the plate 6 at a distance L from the first scanning line L21. The clamp 2C1 is in a standby state and the scanning method described in step 2 is used to scan and form the B end of the plate 6 in sequence.

[0047] This invention specifically relates to a dynamic clamping device. Compared to traditional fixed clamping devices, this invention can effectively improve the inconsistent deformation phenomenon of sheet 6 after laser heating forming. Actual forming results show that, after using this dynamic clamping device, the degree of deformation inconsistency of sheet 6 decreased from 28.1% when using traditional fixed clamping of sheet 6 ends to 5.5%, as shown in the attached figure. Figure 5 As shown, two sets of clamps are used for clamping. During the forming process of sheet 6, one set of clamps always holds sheet 6 to prevent the sheet 6 from shifting position and eliminates the need to adjust the relative position of sheet 6 and laser device multiple times.

[0048] The above descriptions are merely embodiments of the present invention, and common knowledge such as specific technical solutions and / or characteristics are not described in detail here. It should be noted that those skilled in the art can make various modifications and improvements without departing from the technical solutions of the present invention. In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; or they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A dynamic clamping method for laser heating forming of sheet metal, the method employing a dynamic clamping device comprising at least two sets of clamp groups, a slider, and a clamp base, wherein the clamp base is used to place the sheet metal, the two sets of clamp groups are a forming clamp group and a positioning clamp group, the forming clamp group and the positioning clamp group are used to fix the sheet metal on the clamp base, each of the positioning clamp group and the forming clamp group includes at least one symmetrically arranged clamp unit, the forming clamp group fixes the sheet metal during forming, and the positioning clamp group fixes the sheet metal after forming, each clamp unit includes a cylinder, a clamp, and a rotatable fixing block, one end of the clamp is connected to the cylinder piston rod, the rotatable fixing block is fixedly connected to the cylinder, the clamp is hinged to the rotatable fixing block, and when the cylinder piston rod moves up and down, the clamp moves up and down to release and clamp the sheet metal, the cylinder is slidably disposed on the clamp base; characterized in that... The method includes: Step 1: Divide the two ends of the sheet into end A and end B. First, shape end A and select the first scanning line L11 on end A. Select scanning lines L12~L1n in sequence along the center of the sheet. For end B, the scanning lines towards the center of the sheet are L21~L2n in sequence. The fixture group closest to the shaped end is the forming fixture group, and the other fixture group is the positioning fixture group. Step 2: When laser heating and forming the first scanning line L11, the forming fixture group fixes the plate on the fixture base, and the positioning fixture group is in standby state; after the first scanning line L11 is formed, the positioning fixture group clamps the plate, the forming fixture group is released, and the forming fixture group is moved towards the center of the plate until it is at a position of the first preset distance L from the second scanning line L12. The distance between the forming fixture group and the positioning fixture group is set to the second preset distance, and the second scanning line L12 is laser heated and formed. The above process is repeated. Step 3: After end A of the sheet is formed, end B is formed. At this time, the forming fixture group and the positioning fixture group are changed. The forming fixture group is moved to end B and the sheet is clamped at a position at a first preset distance L from the first scanning line L21 of end B. The positioning fixture group is in standby state and the distance between the forming fixture group and the positioning fixture group is set to a second preset distance. The scanning method in step 2 is used to form end B of the sheet in sequence.

2. The dynamic clamping method for laser heating forming of sheet metal according to claim 1, characterized in that: The forming fixture group is located at a first preset distance L of the plate scanning line, the positioning fixture group is located at a second preset distance of the forming fixture group, and the forming fixture group is located between the scanning line and the positioning fixture group.

3. The dynamic clamping method for laser heating forming of sheet metal according to claim 1, characterized in that: It also includes a slider, the cylinder body of the cylinder is fixed on the slider, the bottom of the fixture is provided with a dovetail groove, and the slider is slidably disposed in the dovetail groove.

4. The dynamic clamping method for laser heating forming of sheet metal according to claim 1, characterized in that: It also includes a workbench, on which the fixture base is fixed.

5. The dynamic clamping method for laser heating forming of sheet metal according to claim 1, characterized in that: The rotatable fixing block has a T-shaped structure and a rotatable structure, which drives the clamp to rotate around the center line of the cylinder piston rod. The horizontal part of the rotatable fixing block is fixed on the cylinder, and the rotatable fixing block is hinged to the middle part of the clamp.

6. The dynamic clamping method for laser heating forming of sheet metal according to claim 1, characterized in that: The fixture base includes L-shaped plates, which are symmetrically arranged and face outwards.

7. The dynamic clamping method for laser heating forming of sheet metal according to claim 1, characterized in that: The first preset distance L is calculated as follows: Where K=2 is the distance coefficient, in mm. 3 / s 0.5 W; P is the laser power, in W; d is the spot diameter, in mm; v is the scanning speed, in mm / s.

8. The dynamic clamping method for laser heating forming of sheet metal according to claim 1, characterized in that: When forming the next scanning line, the distance between the position of the positioning fixture group that is in standby clamping the plate and the forming fixture group that clamps the plate for forming the next scanning line is 8~12mm.

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