A method for joining strips, a welding assembly, and a plastic-coated steel strip splicing machine.

Abstract

This invention discloses a strip joining method, a welding assembly, and a plastic-steel strip splicing machine. The method involves overlapping the head of a second strip with the tail of a first strip; pressing and welding the overlapped head of the second strip with the tail of the first strip to form a welded section; the thickness H3 of the welded section satisfies H3=K1·(H1 + H2), 0.55≤K1≤0.9; where K1 is the welding thickness reduction coefficient, H1 is the thickness of the first strip, and H2 is the thickness of the second strip. Appropriate welding pressure maintains the thickness of the welded section at H3, ensuring that a suitable amount of semi-molten material is retained between the first and second strips, with only a small portion of semi-molten material extruded from the welding area, thus ensuring the welding quality and strength of the first and second strips meets the requirements.

Description

Technical Field

[0001] This invention belongs to the field of packaging equipment, and particularly relates to a method for connecting strips, a welding assembly, and a plastic-steel strip splicing machine. Background Technology

[0002] Plastic strapping (also known as packaging strapping or bundling strapping) is a key material for securing and transporting solar cell modules. It is necessary to firmly connect the end of the plastic strapping from the exhausted roll to the beginning of the new roll.

[0003] In the prior art, CN118723179B discloses an automatic cable tie splicing device. The specification describes a method where a first and a second cable tie are overlapped and friction-welded, with high-frequency friction between the first and second connecting parts to fuse them together, achieving a thickness substantially consistent with the cable tie thickness. This requires excessive melting and extrusion of the first and second connecting parts to ensure the fused thickness is substantially consistent with the cable tie thickness, which leads to the following problems.

[0004] First, to achieve a thickness that matches the strapping thickness after the first and second connecting parts are fused together, a large welding pressure is required to squeeze most of the semi-molten material out of the fusion area, leaving only the cold part of the material. This will result in poor fusion and low tensile strength of the strapping after fusion.

[0005] Second, the thickness of the first and second connecting parts after fusion is the same as the thickness of the strapping tape. This requires excessive melting of the material between the first and second connecting parts, which results in a longer friction welding time and affects the strapping tape feeding efficiency.

[0006] Third, the welded part after extrusion is quite wide. Since the strapping is arranged vertically, the waste material cut off by the first cutter will accumulate at the cutting position, affecting the normal supply of subsequent plastic steel strapping.

[0007] Fourth, because the first and second connecting parts are over-melted and extruded to form a welded area, and the first and second friction teeth are arrayed small tooth structures, during the separation of the second friction teeth, the welded area that has been over-melted and cooled will stick to the first or second friction teeth, making it difficult for the strapping to continue to be conveyed forward. Summary of the Invention

[0008] The main objective of this invention is to provide a strip joining method, welding assembly, and plastic-steel strip splicing machine to improve the welding quality of strip materials.

[0009] The present invention achieves the above objectives through the following technical solutions:

[0010] A method for joining strips includes the following steps:

[0011] S10: The head of the second band overlaps with the tail of the first band;

[0012] S20: The head of the second belt and the tail of the first belt are pressed and welded together to form a welded part;

[0013] The weld thickness H3 must meet the following conditions:

[0014] H3 = K1·(H1 + H2), 0.55≤K1≤0.9;

[0015] Where K1 is the welding thickness reduction coefficient, H1 is the thickness of the first zone, and H2 is the thickness of the second zone.

[0016] Specifically, the following steps are included after S20:

[0017] S30: Maintain pressure on the welded part, wherein the pressure ranges from 50 N to F to 2000 N.

[0018] Specifically, the pressure F and the holding time t satisfy the following conditions:

[0019]

[0020] Where A is the welding area, η is the average melt viscosity of the first and second zones, and k is the geometric factor.

[0021] Specifically, the pressure F and the holding time t satisfy the following conditions:

[0022] 100 N·s ≤ F·t ≤ 3000 N·s.

[0023] Specifically, the following steps are included after S30:

[0024] S40: The width W3 after side milling or trimming of both sides of the welded part meets the following conditions:

[0025] 0.5(W1+W2)≤W3≤0.6(W1+W2);

[0026] Where W1 is the width of the first band and W2 is the width of the second band.

[0027] Specifically, in S10, during the process of overlapping the head of the second belt with the tail of the first belt, the head of the second belt and / or the tail of the first belt are aligned so that the head of the second belt and the tail of the first belt completely overlap in the width direction.

[0028] The following steps are included after S30:

[0029] S50: Vertical milling of the surface and / or back of the welded part, the thickness H4 of the welded part after vertical milling meets the following conditions:

[0030] H4 = K2·H3, 0.6≤K2≤0.9, and 0.5(H1+H2)≤H4<H3;

[0031] Where K2 is the thickness reduction factor for vertical milling.

[0032] This invention provides a welding assembly for implementing the aforementioned strip joining method. The welding assembly includes a movable plate, a vertical plate, a pressurizing cylinder, an upper friction head, two connecting rods, a drive arm, and a friction head drive mechanism. A conveying channel is provided on the movable plate, and a lower friction head is provided on the conveying channel. The vertical plate is fixed to the movable plate.

[0033] The cylinder body of the pressurizing cylinder is connected to the upper part of the vertical plate, and the piston rod of the pressurizing cylinder is connected to the sleeve;

[0034] The top of the upper friction head is connected to the sleeve, and the friction surface of the upper friction head is perpendicular to the piston rod axis of the pressurized cylinder;

[0035] The upper ends of the two connecting rods are hinged to the sleeve, and the lower ends are hinged to the side of the upper friction head. The axial direction of the connecting rod hinge axis is parallel to the friction surface of the upper friction head.

[0036] One end of the drive arm is hinged to the upper friction head, and the axial direction of the hinge axis of the drive arm is consistent with the axial direction of the hinge axis of the connecting rod.

[0037] The friction head drive mechanism is connected to the other end of the drive arm, and the friction head drive mechanism drives the upper friction head to reciprocate.

[0038] Furthermore, the welding assembly also includes a bushing, a compression spring, a limiting block, an upper pin, a lower pin, and a limiting component. The upper end of the bushing is fitted around the outer circumference of the sleeve, and the bushing and the sleeve form an axial movement and radial limiting fit. The bottom end of the bushing and the ball groove of the upper friction head are ball bearings.

[0039] The compression spring is located between the bushing and the sleeve, with one end of the compression spring pressing against the sleeve and the other end pressing against the bushing;

[0040] The limiting block is fixed to the vertical plate. The limiting block is located between the piston rod of the pressurized cylinder and the upper friction head. The limiting block has a vertical hole for the sleeve to be accommodated. Waist holes are opened on both sides of the limiting block, and the waist holes are connected to the vertical holes.

[0041] The upper pin passes through the waist hole to hinge the upper end of the connecting rod to the sleeve, and the waist hole of the limiting block restricts the upper pin to move along the length of the waist hole.

[0042] The lower pin passes through the waist hole to connect the lower end of the connecting rod, the upper friction head and the drive arm. The axial directions of the lower pin and the upper pin are parallel to the friction surface of the upper friction head.

[0043] The limiting element is set on the conveying channel. The limiting element is located on one or both sides of the upper friction head, and the limiting element limits the conveying width of the conveying channel.

[0044] The present invention also provides a plastic steel belt splicing machine, including the aforementioned welding assembly and trimming assembly. The trimming assembly trims both sides of the welded part. The trimming assembly includes a side milling cylinder, a sliding plate, a side milling motor, a first side milling cutter and a second side milling cutter. The cylinder body of the side milling cylinder is fixed to the moving plate, and the extension and retraction direction of the piston rod of the side milling cylinder is perpendicular to the bottom surface of the conveying channel groove.

[0045] The slide plate is connected to the piston rod; the side milling motor housing is fixed to the slide plate, and the side milling motor includes two synchronously rotating shafts;

[0046] The first side milling cutter is connected to a shaft of the side milling motor, and the length direction of the first side milling cutter is perpendicular to the bottom surface of the conveying channel groove.

[0047] The second side milling cutter is connected to another shaft of the side milling motor. The second side milling cutter is perpendicular to the bottom surface of the conveyor channel groove. The distance between the cutting edges of the second side milling cutter and the first side milling cutter matches the width of the first belt.

[0048] The plastic steel belt splicing machine also includes a vertical milling assembly, which performs vertical milling on the surface and back of the welded part. The vertical milling assembly includes an upper vertical plate, a first lifting plate, an upper milling motor, an upper milling cutter, and two pressure rollers. The lower part of the upper vertical plate is fixed to the surface of the moving plate. The first lifting plate slides in a direction perpendicular to the bottom surface of the conveying channel groove with the upper vertical plate. The housing of the upper milling motor is fixed to the first lifting plate.

[0049] The upper milling cutter is connected to the shaft of the upper milling motor, and the upper milling cutter is spaced apart from the bottom surface of the conveying channel groove;

[0050] Two pressure rollers are elastically connected to the first lifting plate. The two pressure rollers are located on both sides of the upper milling cutter. The two pressure rollers are arranged along the length of the conveying channel groove. The distance between the two pressure rollers is greater than the welding length between the tail of the first belt and the head of the second belt. The distance between the bottom edge of the pressure roller and the bottom surface of the conveying channel groove is less than the distance between the end face of the upper milling cutter and the bottom surface of the conveying channel groove.

[0051] Furthermore, the vertical milling assembly also includes a lower vertical plate, a second lifting plate, a lower milling motor, and a lower milling cutter. The upper part of the lower vertical plate is fixed to the back of the movable plate; the second lifting plate and the lower vertical plate slide in a direction perpendicular to the bottom surface of the conveying channel groove.

[0052] The lower milling motor housing is fixed to the second lifting plate; the lower milling cutter is connected to the rotating shaft of the lower milling motor, and the lower milling cutter is spaced apart from the bottom surface of the conveying channel groove, with the length direction of the lower milling cutter and the upper milling cutter being the same;

[0053] A through hole is opened at the bottom of the conveying channel trough, and the bottom surface of the trough on both sides of the through hole has an enlarged area to accommodate the pressure roller.

[0054] Compared with the prior art, the present invention has the following technical effects:

[0055] Appropriate welding pressure keeps the thickness of the welded part at H3 = K1·(H1 + H2), 0.55≤K1≤0.9. Not only is a suitable amount of semi-molten material retained between the first and second bands, but only a small portion of the semi-molten material is extruded from the welding area, ensuring the welding quality of the first and second bands and that the welding strength of the first and second bands meets the requirements. Attached Figure Description

[0056] Figure 1 This is a perspective view of the plastic-steel belt splicing machine of the present invention;

[0057] Figure 2 A perspective view of the welding assembly of the present invention;

[0058] Figure 3 for Figure 2 Exploded view;

[0059] Figure 4 for Figure 2 A 3D view of the hidden limiting block;

[0060] Figure 5 for Figure 2 Side view;

[0061] Figure 6 for Figure 5 EE-directed sectional view;

[0062] Figure 7 This is a perspective view of the other side of the welding assembly of the present invention;

[0063] Figure 8 This is a perspective view of the conveying channel and limiting component of the present invention.

[0064] Figure 9 This is a perspective view of the trimming component of the present invention;

[0065] Figure 10 for Figure 9 A 3D image hidden behind the top cover;

[0066] Figure 11 for Figure 10 The front view;

[0067] Figure 12 for Figure 11 FF section view;

[0068] Figure 13 This is a perspective view of the vertical milling assembly of the present invention;

[0069] Figure 14 for Figure 13 A 3D image hidden behind the top cover;

[0070] Figure 15 for Figure 14A three-dimensional view of one side;

[0071] Figure 16 for Figure 14 A three-dimensional view of the mid-dorsal side;

[0072] Figure 17 for Figure 14 The front view;

[0073] Figure 18 for Figure 17 GG-direction sectional view in the middle;

[0074] Figure 19 for Figure 18 A schematic diagram showing the two end mills in the working position;

[0075] Figure 20 This is a rendering of the finished product after processing the tail of the first belt and the head of the second belt. Detailed Implementation

[0076] The following is combined Figures 1 to 20 The following embodiments of the present invention will be described.

[0077] Example 1

[0078] This embodiment is a method for joining strips, including the following steps:

[0079] S10: The head of the second band overlaps with the tail of the first band;

[0080] S20: The head of the second belt and the tail of the first belt are pressed and welded together to form a welded part;

[0081] The weld thickness H3 must meet the following conditions:

[0082] H3 = K1·(H1 + H2), 0.55≤K1≤0.9;

[0083] Where K1 is the welding thickness reduction coefficient, H1 is the thickness of the first zone, and H2 is the thickness of the second zone.

[0084] Compared with the prior art, the present invention has the following technical effects.

[0085] First, the first and second strips are moderately melted, and the thickness of the welded part is kept at H3 = K1·(H1 +H2), 0.55≤K1≤0.9. That is, the welding time between the first and second strips is short and the welding temperature is relatively low. In addition, an appropriate amount of semi-molten material is retained between the first and second strips. This invention can ensure the welding quality of the first and second strips and the connection strength between the first and second strips meets the requirements.

[0086] The welding thickness reduction factor K1 can be 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, or 0.9. Furthermore, the range of the welding thickness reduction factor is 0.75 ≤ K1 ≤ 0.85, which can further improve the welding effect between the first and second bands.

[0087] Secondly, the first and second strips do not need to be excessively melted, reducing the friction welding time and improving the strip feeding efficiency.

[0088] Third, only a small amount of the semi-molten material in the welded part is squeezed out to both sides of the welded part. The width of the welded part is small. The first and second strips after welding can not only be conveyed to the next process normally, but also generate less waste material for the next process to trim the sides of the welded part.

[0089] Fourth, since this embodiment does not require excessive melting, the two friction heads of the friction welding can be smoothly and normally separated, avoiding the welded part after excessive melting from sticking to the friction teeth of the two friction heads after cooling, thus ensuring that the welded strip can be transported normally.

[0090] Example 2

[0091] This embodiment is a method for joining strips, including the following steps:

[0092] S10: The head of the second band overlaps with the tail of the first band;

[0093] S20: The head of the second belt and the tail of the first belt are pressed and welded together to form a welded part;

[0094] The weld thickness H3 must meet the following conditions:

[0095] H3 = K1·(H1 + H2), 0.55≤K1≤0.9;

[0096] Where K1 is the welding thickness reduction coefficient, H1 is the thickness of the first zone, and H2 is the thickness of the second zone;

[0097] S30: Maintain pressure F on the welded part, with the pressure range being 50 N ≤ F ≤ 2000 N.

[0098] Specifically, F can be 60N, 70N, 80N, 90N, 100N, 110N, 120N, 130N, 140N, 150N, 160N, 170N, 180N, 190N, 200N, 210N, 220N, 230N, 240N, 250N, 260N, 270N, 280N, 290N, 300N, 400N, 500N, 600N, 700N, 800N, 900N, 1000N, 1100N, 1200N, 1300N, 1400N, 1500N, 1600N, 1700N, 1800N, or 1900N.

[0099] The pressure holding time range is 0.5S≤t≤10S, where t can be 1S, 1.5S, 2S, 2.5S, 3S, 3.5S, 4S, 4.5S, 5S, 5.5S, 6S, 6.5S, 7S, 7.5S, 8S, 8.5S, 9S, or 9.5S.

[0100] The preferred pressure range F is 100N≤F≤500N, and the corresponding holding time t is 1S≤t≤5S. This ensures the welding quality of the first and second bands while shortening the welding time and significantly improving welding efficiency.

[0101] Specifically, the pressure F and the holding time t satisfy the following conditions:

[0102]

[0103] Where A is the welding area, η is the average melt viscosity of the first and second zones, and k is the geometric factor.

[0104] A = L·W, where L is the welding length between the first and second strips, and W is the welding width between the first and second strips.

[0105] Taking the first and second strips as examples, both made of PET, at a welding temperature of 230℃, the PET melt viscosity η is 500 Pa·s to 1000 Pa·s.

[0106] The value of k is determined based on the shape of the welding area and the flow boundary conditions. In this embodiment, the welding area of ​​the PET plastic strip is rectangular, and the value of k is set to 10. 3 .

[0107] Specifically, the pressure F and the holding time t satisfy the following condition: 100 N·s ≤ F·t ≤ 3000 N·s.

[0108] F·t can specifically be 120 N·s, 140 N·s, 160 N·s, 180 N·s, 200 N·s, 210 N·s, 220 N·s, 230 N·s, 240 N·s, 250 N·s, 260 N·s, 270 N·s, 280 N·s, 290 N·s, 300 N·s, 400 N·s, 500 N·s, 600 N·s, 700 N·s. N·s, 800N·s, 900N·s, 1000N·s, 1100N·s, 1200N·s, 1300N·s, 1400N·s, 1500N·s, 160 0N·s, 1700N·s, 1800N·s, 1900N·s, 2000N·s, 2200N·s, 2400N·s, 2600N·s, 2800N·s.

[0109] The preferred pressure F and holding time t satisfy 200 N·s ≤ F·t ≤ 2000 N·s; a further preferred one is 200 N·s ≤ F·t ≤ 1000 N·s.

[0110] By constraining the pressure F and holding time t of the welded part, on the one hand, the semi-molten material is fully fused and the gas is discharged, ensuring that the molten molecules between the first and second bands are fully diffused; on the other hand, the thickness H3=K1·(H1 + H2) of the welded part is controlled, and an appropriate amount of semi-molten material is retained between the first and second bands to ensure the welding quality of the first and second bands.

[0111] Example 3

[0112] This embodiment provides a welding assembly 40 for implementing the aforementioned strip joining method. The following describes the assembly in conjunction with... Figures 2 to 8 The welding assembly 40 is described below.

[0113] Welding assembly 40 includes a movable plate 20, a vertical plate 41, a pressurizing cylinder 42, an upper friction head 43, two connecting rods 44, a drive arm 45, and a friction head drive mechanism; a conveying channel is provided on the movable plate 20, and a lower friction head 22 is provided at the bottom of the groove of the conveying channel 21; the vertical plate 41 is fixed to the movable plate 20;

[0114] The cylinder body of the pressurizing cylinder 42 is connected to the upper part of the vertical plate 41, and the piston rod of the pressurizing cylinder 42 is connected to the sleeve 421;

[0115] The top of the upper friction head 43 is connected to the sleeve 421, and the friction surface of the upper friction head 43 is perpendicular to the piston rod axis of the pressurized cylinder 42.

[0116] The upper ends of the two connecting rods 44 are hinged to the sleeve 421, and the lower ends are hinged to the side of the upper friction head 43. The axial direction of the hinge axis of the connecting rod 44 is parallel to the friction surface of the upper friction head 43.

[0117] One end of the drive arm 45 is hinged to the upper friction head 43, and the hinge axis of the drive arm 45 is aligned with the hinge axis of the connecting rod 44; the friction head drive mechanism is connected to the other end of the drive arm 45, and the friction head drive mechanism drives the upper friction head 43 to reciprocate.

[0118] By setting two connecting rods 44 with their ends hinged to the sleeve 421 and the upper friction head 43 respectively, the upper friction head 43 can reciprocate stably. In addition, the pressure cylinder 42 applies pressure to the upper friction head 43. The pressure cylinder 42 applies pressure in two working processes: first, during the friction welding process of the upper friction head 43, and second, after the upper friction head 43 finishes welding, the pressure is maintained, thereby improving the welding quality of the welding assembly 40.

[0119] The welding assembly 40 also includes a bushing 422 and a compression spring 423. The upper end of the bushing 422 is sleeved on the outer periphery of the sleeve 421. The bushing 422 and the sleeve 421 form an axial movement and radial limiting fit. The bottom end of the bushing 422 is connected to the ball groove of the upper friction head 43 by balls (not shown in the figure). The compression spring 423 is located between the bushing 422 and the sleeve 421. One end of the compression spring 423 is pressed against the sleeve 421 and the other end is pressed against the bushing 422.

[0120] During the friction welding process of the upper friction head 43, the drive arm 45 drives the upper friction head 43 to reciprocate along the X direction. The top of the upper friction head 43 has a ball groove, and the length direction of the ball groove is consistent with the movement direction of the drive arm 45. The ball groove at the top of the upper friction head 43 and the bottom of the bushing 422 are balls. The movement direction of the bushing 422 is only the length direction of the piston rod of the pressurizing cylinder 42. The pressurizing cylinder 42 transmits pressure through the bushing 422 and the balls.

[0121] Pressure is transmitted through the connecting rods 44 on both sides of the upper friction head 43 and the balls under the bushing 422, which prevents the upper friction head 43 from rotating too much around the lower hinge axis, ensuring that the pressure of the upper friction head 43 can be evenly distributed and improving the welding quality.

[0122] During the downward pressing of the upper friction head 43, the compression spring 423 between the bushing 422 and the sleeve 421 can provide buffering to prevent the upper friction head 43 from hard impacting and damaging the strip or the lower friction head 22.

[0123] The welding assembly 40 also includes a limiting block 46, an upper pin 47 and a lower pin 48. The limiting block 46 is fixed to the vertical plate 41. The limiting block 46 is located between the piston rod of the pressurizing cylinder 42 and the upper friction head 43. The limiting block 46 has a vertical hole 461 for the sleeve 421 to be accommodated. Waist holes 462 are opened on both sides of the limiting block 46, and the waist holes 462 are connected to the vertical hole 461.

[0124] The upper pin 47 passes through the waist hole 462 and hinges the upper end of the connecting rod 44 to the sleeve 421. The waist hole 462 of the limiting block 46 limits the movement of the upper pin 47 along the length of the waist hole 462. The lower pin 48 passes through the waist hole 462 and hinges the lower end of the connecting rod 44, the upper friction head 43 and the drive arm 45. The axial directions of the lower pin and the upper pin 47 are parallel to the friction surface of the upper friction head 43.

[0125] By setting a limit block 46 to fix it to the upright plate 41, and starting a vertical hole 461 in the middle of the limit block 46, it plays a guiding role for the sleeve 421, ensuring vertical movement accuracy, reducing uneven wear, and improving welding consistency.

[0126] The waist holes 462 on both sides of the limiting block 46 can restrict the movement path of the upper pin 47, ensure the precise movement trajectory of the connecting rod 44, and improve welding stability.

[0127] The outer diameter of the sleeve 421 matches the inner diameter of the vertical hole 461, allowing the sleeve 421 to move along the length of the vertical hole 461. During the high-frequency vibration of the upper friction head 43, the limiting block 46 restricts the radial position of the sleeve 421, which not only improves the stability of the entire welding assembly 40 but also prevents the pressure cylinder 42 from being subjected to bending moment during the operation of the upper friction head 43 driven by the drive arm 45, thus extending the service life of the pressure cylinder 42.

[0128] The friction head drive mechanism includes a reduction gearbox 491 and a welding motor 492. The reduction gearbox 491 is fixed to the movable plate 20. The reduction gearbox 491 includes a power input end and a power output end. The power output end is connected to the drive arm 45.

[0129] The shaft of the welding motor 492 is connected to the power input end of the gearbox 491. The welding motor 492 drives the upper friction head 43 to reciprocate through the gearbox 491 and the drive arm 45.

[0130] The materials to be welded are a first strip and a second strip stacked together. The friction surfaces of the upper friction head 43 and the lower friction head 22 are provided with protrusions. The protrusions of the upper friction head 43 and the lower friction head 22 can penetrate the stacked first strip and the second strip respectively. In this way, the relative position of the upper friction head 43 and the first strip is determined, and the relative position of the lower friction head 22 and the second strip is fixed. The first strip and the second strip are subjected to high-frequency friction to ensure the welding quality of friction welding.

[0131] like Figure 8 As shown, the conveying channel 21 includes a conveying trough 211, and a top cover 212 is provided on the conveying trough 211. The welding assembly 40 also includes a limiting member 80, which is disposed on the top cover 212. The limiting member 80 is located on one or both sides of the upper friction head 43, and the limiting member 80 limits the conveying width of the conveying channel 21.

[0132] The conveying trough 211 and the upper cover 212 enclose each other to form a conveying channel 21 for the strip, and the limiting member 80 is provided on the upper cover 212.

[0133] The limiting component 80 can constrain the position of the strip, prevent the upper and lower strips from misaligning during welding, and improve welding quality.

[0134] The limiting component 80 includes limiting plates 81 and limiting posts 82. One end of the two limiting plates 81 is hinged to the upper cover 212, and the upper ends of the two limiting posts 82 are fixed to the other ends of the limiting plates 81. The limiting posts 82 are located within the conveying channel 21, and the two limiting posts 82 can be adjusted along the width direction of the conveying channel 21. The adjustable spacing between the two limiting posts 82 can accommodate strips of different widths, thus broadening the applicability of the welding assembly 40.

[0135] Example 4

[0136] Based on Example 2, this example further includes the following steps after S30.

[0137] S40: The width W3 after side milling or trimming of both sides of the welded part meets the following conditions:

[0138] 0.5(W1+W2)≤W3≤0.6(W1+W2); where W1 is the width of the first band and W2 is the width of the second band.

[0139] Provided that the width of the welded part can pass through the next packaging process of the tape-making machine, the width W3 of the welded part is set to 0.5(W1+W2)≤W3≤0.6(W1+W2) to improve the connection strength of the welded part.

[0140] In this embodiment, the trimming component 50 performs side milling or trimming on both sides of the welded portion. The following describes the process in conjunction with... Figures 9 to 12 The trimming component 50 is described below.

[0141] The trimming assembly 50 includes a moving plate 20, a side milling motor 51, a first side milling cutter 52, a second side milling cutter 53, and a side milling drive mechanism. The moving plate 20 is provided with a conveying channel 21. The side milling motor 51 includes two synchronously rotating shafts.

[0142] The first side milling cutter 52 is connected to a shaft of the side milling motor 51. The first side milling cutter 52 is located on one side of the conveying channel 21, and the length direction of the first side milling cutter 52 is perpendicular to the bottom surface of the groove of the conveying channel 21.

[0143] The second side milling cutter 53 is connected to another shaft of the side milling motor 51. The second side milling cutter 53 is located on the other side of the conveying channel 21. The second side milling cutter 53 is parallel to the first side milling cutter 52. The distance between the cutting edges of the second side milling cutter 53 and the first side milling cutter 52 in the direction perpendicular to the conveying direction of the strip is consistent with the width of the strip.

[0144] The side milling drive mechanism is connected to the housing of the side milling motor 51. The side milling drive mechanism can drive the side milling motor 51 to reciprocate along the bottom surface of the groove perpendicular to the conveying channel 21.

[0145] The spacing between the first side milling cutter 52 and the second side milling cutter 53 is matched with the width of the strip. The sides of the welded joint of the two plastic steel strips are milled, and the milled plastic steel strip can be supplied normally to the packaging process.

[0146] The side milling drive mechanism includes a side milling cylinder 54 and a slide plate 55. The cylinder body of the side milling cylinder 54 is fixed to the moving plate 20, and the extension and retraction direction of the piston rod of the side milling cylinder 54 is perpendicular to the bottom surface of the conveying channel 21. One side of the slide plate 55 is slidably engaged with the cylinder body of the side milling cylinder 54, and the slide plate 55 is connected to the piston rod of the side milling cylinder 54.

[0147] The cylinder body of the side milling cylinder 54 has a guide rail, and the guide groove of the slide plate 55 directly matches the guide rail on the cylinder body. The trimming assembly 50 has a high degree of integration.

[0148] By matching the spacing of the first and second side milling cutters to the strip width, the parallelism of the strip's welded edges is ensured, achieving precise trimming. Using two side milling cutters, a single milling operation can trim both sides of the strip, improving trimming efficiency.

[0149] In addition, the waste particles milled from both sides of the welding section are small, which prevents the waste from getting stuck on the conveying channel 21 and ensures that the strip can be conveyed normally on the conveying channel 21.

[0150] Example 5

[0151] This embodiment provides a strip joining method, including the following steps.

[0152] S10: During the process of overlapping the head of the second belt with the tail of the first belt, the head of the second belt and / or the tail of the first belt are aligned so that the head of the second belt and the tail of the first belt completely overlap in the width direction.

[0153] S20: The head of the second belt and the tail of the first belt are pressed and welded together to form a welded part;

[0154] The weld thickness H3 must meet the following conditions:

[0155] H3 = K1·(H1 + H2), 0.55≤K1≤0.9; where K1 is the welding thickness reduction coefficient, H1 is the thickness of the first zone, and H2 is the thickness of the second zone.

[0156] S30: Maintain pressure F on the welded part, with the pressure range being 50 N ≤ F ≤ 2000 N.

[0157] S50: Vertical milling of the surface and / or back of the welded part, the thickness H4 of the welded part after vertical milling meets the following conditions:

[0158] H4 = K2·H3, 0.6≤K2≤0.9, and 0.5(H1+H2)≤H4<H3; where K2 is the thickness reduction coefficient for vertical milling.

[0159] The welded part is milled on both the surface and back sides using the milling assembly 60, as described below. Figures 13 to 19 The vertical milling assembly 60 is described below.

[0160] The vertical milling assembly 60 includes an upper vertical plate 61a, a first lifting plate 62a, an upper milling motor 63a, an upper milling cutter 64a, and two pressure rollers 65. A conveying channel 21 is provided on the movable plate 20. The lower part of the upper vertical plate 61a is fixed to the surface of the movable plate 20.

[0161] The first lifting plate 62a and the upper vertical plate 61a slide in a direction perpendicular to the bottom surface of the conveying channel 21; the housing of the upper milling motor 63a is fixed to the first lifting plate 62a;

[0162] The upper milling cutter 64a is connected to the rotating shaft of the upper milling motor 63a, and the upper milling cutter 64a is arranged at intervals with the bottom surface of the conveying channel 21.

[0163] Two pressure rollers 65 are elastically connected to the first lifting plate 62a. The two pressure rollers 65 are located on both sides of the upper milling cutter 64a. The two pressure rollers 65 are arranged along the length of the conveying channel 21. The distance between the bottom edge of the pressure roller 65 and the bottom surface of the conveying channel 21 is less than the distance between the end face of the upper milling cutter 64a and the bottom surface of the conveying channel 21.

[0164] When the upper milling cutter 64a is not working, the distance between the bottom edge of the pressure roller 65 and the bottom surface of the conveying channel 21 groove is less than the distance between the end face of the upper milling cutter 64a and the bottom surface of the conveying channel 21 groove.

[0165] During the operation of this invention, the first lifting plate 62a drives the two pressure rollers 65 and the upper milling cutter 64a to descend synchronously. After the two pressure rollers 65 press against both sides of the welded part, the first lifting plate 62a drives the upper milling cutter 64a to continue descending. At this time, the relative positions of the two pressure rollers 65 and the conveying channel 21 remain unchanged, the springs of the pressure rollers 65 are compressed, and the upper milling cutter 64a descends to achieve milling of the surface of the welded part. Vertical milling is performed on one side of the welded part, thus achieving surface thickness reduction of the welded part.

[0166] First, the two pressure rollers 65 elastically press the strip on both sides of the welding part against the bottom surface of the conveying channel 21, preventing the welding part from shifting on the conveying channel 21 during the milling process on one side of the strip, thus enabling precise milling and thinning of the welding part.

[0167] Secondly, during the process of pressing the two pressure rollers 65 down onto the bottom surface of the conveying channel 21, the two pressure rollers 65 can elastically extend and retract to adapt to different specifications of strip thickness.

[0168] Third, the pressure roller 65 elastically clamps the strip, which can absorb the vibration of the entire vertical milling assembly 60 during milling and prevent high-frequency vibration from affecting the connection strength of the various components of the vertical milling assembly 60.

[0169] Fourth, the distance between the two pressure rollers 65 is greater than the welding length between the tail of the first belt and the head of the second belt, so that the upper milling cutter 64a can work normally.

[0170] The vertical milling assembly 60 also includes a lower vertical plate 61b, a second lifting plate 62b, a lower milling motor 63b, and a lower milling cutter 64b. The upper part of the lower vertical plate 61b is fixed to the back of the moving plate 20. The second lifting plate 62b and the lower vertical plate 61b are slidably engaged in a direction perpendicular to the bottom surface of the conveying channel 21. The housing of the lower milling motor 63b is fixed to the second lifting plate 62b. The lower milling cutter 64b is connected to the shaft of the lower milling motor 63b. The lower milling cutter 64b is spaced apart from the bottom surface of the conveying channel 21. The length direction of the lower milling cutter 64b is consistent with that of the upper milling cutter 64a.

[0171] If only one side of the weld is milled in the thickness direction, the unmelted normal strip of the weld will be removed, which will affect the tensile strength of the weld.

[0172] like Figure 17 and Figure 18 As shown, the upper milling cutter 64a and the lower milling cutter 64b move along the Z1 and Z2 directions respectively, as... Figure 19 As shown, the upper milling cutter 64a and the lower milling cutter 64b work together to mill the excess material on the surface and back of the strip welded part. The thickness uniformity of the welded part reaches ±0.1mm. The above-mentioned solution of the present invention mills both sides of the welded part, that is, it realizes the simultaneous reduction of the thickness of the surface and back of the welded part, avoiding affecting the tensile strength of the welded part. The simultaneous processing of the strip welded part on both sides not only improves the processing efficiency, but more importantly, it ensures the tensile strength of the strip welded part.

[0173] The bottom of the conveying channel 21 has a through hole, and the bottom surface of the channel on both sides of the through hole has an enlarged area to accommodate the pressure roller 65.

[0174] The vertical milling assembly also includes an upper slide rail, an upper slide block, and an upper cylinder 66a. The upper slide rail is fixed to the surface of the upper vertical plate 61a, and the length direction of the upper slide rail is perpendicular to the axial direction of the upper milling cutter 64a.

[0175] The upper slider is fixed to the first lifting plate 62a, and the upper slider slides in conjunction with the upper slide rail; the cylinder body of the upper cylinder 66a is fixed to the back of the upper vertical plate 61a, the piston rod of the upper cylinder 66a is connected to the first lifting plate 62a, and the length direction of the piston rod of the upper cylinder 66a is parallel to the length direction of the upper slide rail.

[0176] The vertical milling assembly also includes a lower slide rail, a lower slide block, and a lower cylinder 66b. The lower slide rail is fixed to the surface of the lower vertical plate 61b, and the length direction of the lower slide rail is perpendicular to the axial direction of the lower milling cutter 64b.

[0177] The lower slider is fixed to the second lifting plate 62b, and the lower slider slides in conjunction with the lower slide rail; the cylinder body of the lower cylinder 66b is fixed to the back of the lower vertical plate 61b, the piston rod of the lower cylinder 66b is connected to the second lifting plate 62b, and the length direction of the piston rod of the lower cylinder 66b is parallel to the length direction of the lower slide rail.

[0178] The vertical milling assembly also includes an upper damper 67a and a lower damper 67b. The upper damper 67a is fixed to the movable plate 20, and the head of the upper damper 67a is located on the descending path of the first lifting plate 62a. The lower damper 67b is fixed to the movable plate 20, and the head of the lower damper 67b is located on the ascending path of the second lifting plate 62b.

[0179] The vertical milling assembly also includes a material collection box 68 and a waste pipe 69. The material collection box 68 is located on the outer periphery of the lower milling cutter 64b, and a discharge port is opened on one side of the material collection box 68. One end of the waste pipe 69 is connected to the discharge port of the material collection box 68, and the other end is connected to a negative pressure source.

[0180] The conveying channel 21 includes a conveying trough 211 and an upper cover 212. The conveying trough 211 is disposed on the moving plate 20. The upper cover 212 covers the conveying channel 21. The upper cover has an air blowing hole 213. The air blowing hole is located on one side of the upper milling cutter 64a. The air blowing hole is connected to the positive pressure source through a pipeline.

[0181] The following uses the materials and dimensions of the first and second strips as examples to illustrate the specific technical parameters of the welding assembly 40 and the milling assembly 60.

[0182] Both the first and second strips are made of PET material, with a thickness of 0.7mm and a width of 15±0.2mm. The maximum tensile force that the first and second strips can withstand before welding is 4200N.

[0183] The welding motor speed is 1500-4000 rpm, the welding time is 1-5 seconds, the holding time is 1-5 seconds, and the holding pressure is 100-500 N. The misalignment distance between the tail of the first belt and the head of the second belt after overlapping is 0-1.5 mm.

[0184] The thickness H3 of the welded part formed by welding the first and second bands is 1-1.2mm; the length L of the welded part is 12-17.5mm; and the weld width W is 15mm.

[0185] The thickness H4 of the welded parts after milling of the vertical milling assembly 60 is 0.8-0.96mm.

[0186] The welding motor speed was set to 2500 rpm, the welding time to 3 seconds, the holding time t to 3 seconds, and the thickness of the welded part to 1.1 mm. After vertical milling the welded parts of the first and second belts, the maximum tensile force that the welded part could withstand was tested. See the table below.

[0187]

[0188] When the thickness of the welded part after vertical milling is 0.8mm, the average value of the maximum tensile force that the welded part can withstand is 1776.4N, and the maximum and minimum tensile forces are 2011N and 1548N, respectively.

[0189] When the thickness of the welded part after vertical milling is 0.85mm, the average value of the maximum tensile force that the welded part can withstand is 1810.5N, and the maximum and minimum tensile forces are 1931N and 1603N, respectively.

[0190] When the thickness of the welded part after vertical milling is 0.9mm, the average value of the maximum tensile force that the welded part can withstand is 1969.8N, and the maximum and minimum tensile forces are 2372N and 1562N, respectively.

[0191] like Figure 20 The image shows the effect after the tail of the first belt and the head of the second belt are welded, trimmed, and milled using a plastic steel belt splicing machine.

[0192] Example 6

[0193] like Figure 1 As shown, a plastic steel belt splicing machine adopts the belt splicing method of the aforementioned embodiment.

[0194] The conveying channel 21 has an inlet 21a and an outlet 21b at its two ends. The plastic-steel belt splicer includes a cutting assembly 30, a welding assembly 40, a limiting component 80, an edge trimming assembly 50, a milling assembly 60, and a conveying assembly 70 arranged sequentially along the conveying direction on the conveying channel 21. The welding assembly 40, edge trimming assembly 50, milling assembly 60, and limiting component 80 have been described in the previous embodiments and will not be repeated here.

[0195] The following describes the structure and operation of the cutting component 30 and the conveying component 70.

[0196] A notch is made in the conveying channel 21; the cutting assembly 30 includes scissors and a cutting cylinder, with the scissor blades located at the notch in the conveying channel 21; the cylinder body of the cutting cylinder is fixed to the moving plate 20, and the piston rod of the cutting cylinder is connected to the scissors, enabling the cutting cylinder to drive the scissors to cut.

[0197] The conveying assembly 70 includes a conveying motor 71, which is fixed to the back of the moving plate 20; an active conveying wheel is connected to the shaft of the conveying motor 71; and a conveying pressure roller 72 is elastically pressed onto the active conveying wheel. The conveying assembly 70 is located at the outlet 21b of the conveying channel 21. With the cutting position as the reference point, the conveying assembly 70 actively conveys the strip at a set distance so that the tail of the first strip is located at the welding station.

[0198] After the first belt feeding is completed, the present invention sets a cutting component to cut the first belt. The cutting position is used as a reference point to set the conveying distance of the conveying motor 71. That is, the conveying distance of the conveying motor 71 is the distance from the cutting position to the welding station. In this way, the tail of the first belt can be accurately conveyed to the welding station of the welding component 40 to complete the welding preparation of the tail of the first belt and improve the welding quality of the welding component 40.

[0199] The above descriptions are merely some embodiments of the present invention. Those skilled in the art can make various modifications and improvements without departing from the inventive concept of the present invention, and these all fall within the scope of protection of the present invention.

Claims

1. A method for joining strips, characterized in that, Includes the following steps: S10: The head of the second band overlaps with the tail of the first band; S20: The head of the second belt and the tail of the first belt are pressed and welded together to form a welded part; The thickness H3 of the welded portion satisfies the following condition: H3 = K1·(H1 + H2), 0.55≤K1≤0.9; where K1 is the welding thickness reduction coefficient, H1 is the thickness of the first band, and H2 is the thickness of the second band; S30: Maintain pressure on the welded part, wherein the pressure ranges from 50 N ≤ F ≤ 2000 N; The pressure F and the holding time t satisfy the following conditions: Where A is the welding area, η is the average melt viscosity of the first and second zones, and k is the geometric factor; S40: The width W3 after side milling or cutting the two sides of the welded part satisfies the following condition: 0.5(W1+W2)≤W3≤0.6(W1+W2); where W1 is the width of the first band and W2 is the width of the second band.

2. The strip joining method according to claim 1, characterized in that, The pressure F and the holding time t satisfy the following condition: 100 N·s ≤ F·t ≤ 3000 N·s.

3. The strip joining method according to claim 1, characterized in that, In S10, during the process of overlapping the head of the second belt with the tail of the first belt, the head of the second belt and / or the tail of the first belt are straightened so that the head of the second belt and the tail of the first belt completely overlap in the width direction. The following steps are included after S30: S50: Vertical milling of the surface and / or back of the welded part, the thickness H4 of the welded part after vertical milling meets the following conditions: H4 = K2·H3, 0.6≤K2≤0.9, and 0.5·(H1+H2)≤H4<H3; Where K2 is the thickness reduction factor for vertical milling.

4. A welding assembly for implementing the strip joining method of claim 1, characterized in that, include: A movable plate is provided with a conveying channel, and a lower friction head is provided on the conveying channel; An upright plate, which is fixed to the movable plate; A pressurizing cylinder, the cylinder body of which is connected to the upper part of the vertical plate, and the piston rod of the pressurizing cylinder is connected to a sleeve; The upper friction head has its top connected to the sleeve, and the friction surface of the upper friction head is perpendicular to the piston rod axis of the pressurized cylinder. Two connecting rods, the upper end of which is hinged to the sleeve and the lower end of which is hinged to the side of the upper friction head, and the axial direction of the connecting rod hinge axis is parallel to the friction surface of the upper friction head; A drive arm, one end of which is hinged to the upper friction head, wherein the hinge axis of the drive arm is aligned with the hinge axis of the connecting rod. A friction head drive mechanism is connected to the other end of the drive arm, and the friction head drive mechanism drives the upper friction head to reciprocate. A bushing, the upper end of which is fitted around the outer periphery of the sleeve, the bushing and the sleeve form an axially movable and radially limited fit, and the bottom end of the bushing and the ball groove of the upper friction head are balls; A compression spring is located between the bushing and the sleeve, with one end of the compression spring pressing against the sleeve and the other end pressing against the bushing; A limiting block is fixed to the upright plate. The limiting block is located between the piston rod of the pressurized cylinder and the upper friction head. The limiting block has a vertical hole for the sleeve to be accommodated. Waist holes are opened on both sides of the limiting block. The waist holes are connected to the vertical hole. The upper pin passes through the waist hole and hinges the upper end of the connecting rod to the sleeve. The waist hole of the limiting block limits the movement of the upper pin along the length of the waist hole. The lower pin passes through the waist hole and hinges the lower end of the connecting rod, the upper friction head, and the drive arm. The axial directions of the lower pin and the upper pin are parallel to the friction surface of the upper friction head. A limiting member is disposed on the conveying channel, the limiting member being located on one or both sides of the upper friction head, the limiting member defining the conveying width of the conveying channel.

5. A plastic-steel belt splicing machine, characterized in that, Including a trimming assembly and a welding assembly as described in claim 4, the trimming assembly trims both sides of the welded portion, the trimming assembly comprising: A side-milling cylinder, the cylinder body of which is fixed to the moving plate, wherein the piston rod of the side-milling cylinder extends and retracts in a direction perpendicular to the bottom surface of the conveying channel groove; A sliding plate, which is connected to the piston rod; A side-milling motor, the housing of which is fixed to the slide plate, the side-milling motor comprising two synchronously rotating shafts; A first side milling cutter is connected to a shaft of the side milling motor, and the length direction of the first side milling cutter is perpendicular to the bottom surface of the conveying channel groove. The second side milling cutter is connected to another shaft of the side milling motor. The second side milling cutter is perpendicular to the bottom surface of the conveying channel groove. The distance between the cutting edges of the second side milling cutter and the first side milling cutter is consistent with the width of the first belt.

6. The plastic-steel belt splicing machine according to claim 5, characterized in that, It also includes a milling assembly for milling the surface and back of the weld, the milling assembly comprising: The upper plate is fixed to the surface of the movable plate at its lower part. The first lifting plate is slidably engaged with the upper upright plate in a direction perpendicular to the bottom surface of the conveying channel groove; The upper milling motor has its housing fixed to the first lifting plate; An upper milling cutter is connected to the shaft of the upper milling motor, and the upper milling cutter is arranged at intervals with the bottom surface of the conveying channel groove; Two pressure rollers are elastically connected to the first lifting plate. The two pressure rollers are located on both sides of the upper milling cutter. The two pressure rollers are arranged along the length of the conveying channel groove. The distance between the two pressure rollers is greater than the welding length between the tail of the first belt and the head of the second belt. The distance between the bottom edge of the pressure roller and the bottom surface of the conveying channel groove is less than the distance between the end face of the upper milling cutter and the bottom surface of the conveying channel groove. The lower plate is fixed to the back of the movable plate at its upper part; The second lifting plate is slidably engaged with the lower upright plate in a direction perpendicular to the bottom surface of the conveying channel groove; The lower milling motor has its housing fixed to the second lifting plate; The lower milling cutter is connected to the shaft of the lower milling motor. The lower milling cutter is arranged at intervals with the bottom surface of the conveying channel groove. The length direction of the lower milling cutter is the same as that of the upper milling cutter.

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