Machining device and method for tin plate three-piece tin body

Abstract

The invention provides a tin plate three-piece can body machining device and method. The device comprises a slitting roller cutting machine, a batten conveying table, a small material piece roller cutting machine, a first conveying belt, a second conveying belt, a turning conveying belt, a middle small material piece conveying belt, an edge small material piece conveying belt and a small material piece conveying belt. The method comprises the steps that the size of a large material sheet is designed to enable the height direction of a can body to be perpendicular to the rolling direction of a steel coil, the large material sheet is cut into battens, the battens are machined into small material sheets, the small material sheets on the left side and the small material sheets on the right side are placed on the same conveying belt after the small material sheets on the left side are rotated by 180 degrees, and the small material sheets in the middle are placed on another conveying belt; and respectively conveying to a welding machine and welding by adopting different welding processes. The welding quality problem occurring under the condition that the height direction of the tank body is perpendicular to the rolling direction of the steel coil is solved, the problems of insufficient welding of welding seams of the side tank and splashing of welding seams of the middle tank are avoided, and the product quality and the production efficiency are improved.

Description

Technical Field

[0001] The invention relates to the field of metal packaging, and in particular to a processing device and method for a tinplate three-piece can body. Background Art

[0002] Tinplate, also known as tinplate, refers to a steel plate with a thin layer of metallic tin on the surface. It has good corrosion resistance, good formability, and is easy to weld. The coating is non-toxic and odorless, which can prevent iron from dissolving into the packaged objects. It also has a bright surface and can be printed with pictures to beautify the products. It is mainly used in the food and beverage industry, and secondly in packaging materials for chemical paints, oils, and medicines.

[0003] There are two main categories of can production: three-piece cans and two-piece cans. Two-piece cans are metal containers consisting of a can lid and an integral seamless stamped can body with a bottom; three-piece cans are made of tinplate and are formed and connected. They include a can body, a can bottom and a can lid, and the can body has seams and is rolled with the can body, can bottom and can lid. Three-piece cans have good rigidity, can produce cans of various shapes, have a high material utilization rate, are easy to change in size, have mature production technology, and have a wide variety of packaging products. They are often used in food, beverages, dry powders, chemical products, and spray products.

[0004] There are two main methods for joining three-piece can bodies: soldering and resistance seam welding. The former was used earlier, but has been phased out due to the lead contained in soldering. The production process of the can body made by resistance seam welding: tin plate → paint (using blank paint) → iron cutting → rolling → resistance seam welding → inside and outside paint of weld → flanging → can sealing → rib rolling → finished product. Resistance seam welding completely breaks through the lead pollution problem caused by traditional soldered cans, and has low energy consumption and less material consumption, and is far more widely used than two-piece shallow punching and thin-wall deep drawing can making technology.

[0006] The production process of small pieces for three-piece can bodies mainly includes: unwinding and shearing tinplate steel coils into large pieces, processing the large tinplate pieces into strips through the slitting roller cutting machine and placing them on the strip conveying table, the strip conveying table transports the strips to the small piece roller cutting machine to process them into small pieces, and places them in the small piece bin. When the small piece bin is full, the small piece pile is sent to the welding machine through the conveyor belt and welded along the height direction of the can body. The equipment for processing small pieces for three-piece can bodies consists of: slitting roller cutting machine, strip conveying table, small piece roller cutting machine, and small piece bin.

[0007] However, due to the deformation of the rollers during the rolling of tinplate steel coils and the additional electric field at the edges during tin plating, the substrate at the edges becomes thinner and the tin layer thickens within 3 to 5 mm at the edges, which is the so-called "edge effect". This results in changes in resistance and welding heat when making the can body, which will cause welding quality problems.

[0008] Welding quality problems are divided into the following two situations. One situation: the height direction of the can body is perpendicular to the rolling direction of the steel coil. At this time, the direction of the weld is also perpendicular to the rolling direction of the steel coil. In order to ensure the welding quality of most intermediate tanks, the welding current is generally low, and it is easy for the welds of the edge tanks to have cold welds at both ends. Another situation: the height direction of the can body is consistent with the rolling direction of the steel coil. At this time, the direction of the weld is also consistent with the rolling direction of the steel coil. In order to ensure the welding quality of most of the middle can bodies, the resistance seam welding current is generally low. At this time, the contact resistance of the edge can body is reduced due to the thickening of the tin layer and the thinning of the substrate. The weld heat is low, and it is easy for the entire weld of the edge can to have cold welds.

[0009] However, if the welding current must be increased to ensure the welding quality of the edge tank, spatter will easily appear on the weld of the middle piece. In order to ensure the welding quality of the edge of the edge piece, the welding current is increased to 3250A, and spatter appears on the weld of the middle piece C3, resulting in unqualified corrosion resistance of the weld.

[0010] Chinese patents CN114932381A and CN118875653A propose two methods and equipment for processing tinplate three-piece can body sheets, both of which use the method of making the can body in the same height direction as the steel coil rolling direction to avoid weld quality problems. However, in order to save materials, the can body height direction may be perpendicular to the steel coil rolling direction.

[0011] Therefore, it is necessary to develop a new processing device and method that can avoid welding quality problems when the height direction of the can body is perpendicular to the rolling direction of the steel coil. Summary of the invention

[0012] The purpose of the present invention is to provide a tinplate three-piece can body processing device and method to solve the welding quality problem that occurs when the can body height direction is perpendicular to the steel coil rolling direction.

[0013] To achieve the above-mentioned purpose, in a first aspect, the present invention provides a processing device for a tinplate three-piece can body, comprising:

[0014] Uncoiling and shearing device uncoils the tinplate coil and cuts it into large sheets according to the design size of the can body, and ensures that the height direction of the can body is perpendicular to the rolling direction of the tinplate coil;

[0015] Slitting roller cutting machine cuts the printed tinned sheet into N rows of strips, and ensures that the cutting direction is parallel to the height direction of the can body;

[0016] The slat conveying platform is used to convey the slats cut by the slit roller to the small sheet roller cutting machine, and the conveying direction is perpendicular to the height direction of the can body;

[0017] The small sheet roller cutting machine is used to receive the sheet conveyed by the slat conveyor and cut each row of sheet into M rows of small sheets, and convey the first row of small sheets to the first conveyor belt, the Mth row of small sheets to the second conveyor belt, and the remaining small sheets to the middle small sheet conveyor belt;

[0018] The turning conveyor belt is used to receive the small pieces on the first conveyor belt, rotate them 180 degrees and then convey them to the edge small piece conveyor belt;

[0019] The edge small piece conveyor belt receives the small pieces on the turning conveyor belt and the second conveyor belt;

[0020] The middle small sheet conveyor belt and the side small sheet conveyor belt convey the small sheets thereon to the small sheet conveyor belt in a time-sharing manner;

[0021] The small sheet conveyor belt is used to convey the small sheets thereon to the welding machine.

[0022] In some optional embodiments of the present invention, the welding machine uses I1 current to weld the incoming materials from the middle small-sheet conveyor belt, and uses I2 current to weld the incoming materials from the side small-sheet conveyor belt.

[0023] Preferably, I1<I2.

[0024] In some optional embodiments of the present invention, the small-sheet conveyor belt transports the incoming materials of the edge small-sheet conveyor belt and the middle small-sheet conveyor belt to different welding machines or different welding stations of the same welding machine respectively.

[0025] In some optional embodiments of the present invention, the turning conveyor belt comprises two 90° turning conveyor belts spliced ​​into 180°, which are used to rotate the first column of small webs by 180°.

[0026] In a second aspect, the present invention provides a method for processing a tinplate three-piece can body, comprising:

[0027] Processing the steel coil into a large sheet, the size of the large sheet is such that the height direction of the can body is perpendicular to the rolling direction of the steel coil;

[0028] Using a slitting roller cutter to shear the large sheet into strips, and shearing the large sheet into N rows of strips perpendicular to the rolling direction of the steel coil;

[0029] Use a small-chip roller cutter to process each strip into M rows of small chips;

[0030] The first row of small pieces are rotated 180 degrees and placed on the edge small piece conveyor belt together with the Mth row of small pieces, and the remaining small pieces are placed on the middle small piece conveyor belt;

[0031] The middle small piece conveyor belt and the side small piece conveyor belt convey the small pieces thereon to the welding machine through the small piece conveyor belts at different times, and different welding processes are used for welding.

[0032] In some optional embodiments of the present invention, the welding machine uses I1 current to weld the incoming materials from the middle small-sheet conveyor belt, and uses I2 current to weld the incoming materials from the side small-sheet conveyor belt; I1<I2.

[0033] In some optional embodiments of the present invention, the first row of small webs is transported to the turning conveyor belt via the first conveyor belt, and the turning conveyor belt rotates them 180° and places them on the edge small web conveyor belt.

[0034] In some optional embodiments of the present invention, the Mth row of small webs are directly placed on the small web conveyor belt of the edge placement section through the first conveyor belt.

[0035] Compared with the prior art, the present invention has the following beneficial effects:

[0036] The processing device and method provided by the present invention weld the middle can body and the side can body separately. The middle can body is welded with normal current. For the side can body, an additional current is added to the part with "side effect" for welding to avoid the influence of the edge effect on the welding quality. In this way, the weld quality of the side can and the middle can can meet the requirements. In particular, the present invention can also achieve good welding quality when the height direction of the can body is perpendicular to the rolling direction of the steel coil, effectively solving the problems of cold welding or spattering existing in traditional processes, and improving product quality and production efficiency. Specifically:

[0037] 1. By processing the middle can body and the side can body separately and using different welding current parameters, the welding quality problem caused by the edge effect of the tinplate is effectively solved, ensuring that the welding quality of all can bodies can meet the requirements.

[0038] 2. In the processing of small edge pieces, the left small piece is rotated 180° and placed on the same conveyor belt as the right small piece, so that the edge effects of the two are consistent, and the same welding parameters can be used for processing, which simplifies the process and improves production efficiency.

[0039] 3. Even in a processing mode where the height direction of the can body is perpendicular to the rolling direction of the steel coil, the welding quality can be ensured by the method and device of the present invention, thereby increasing the material utilization rate and reducing the production cost.

[0040] 4. The device structure of the present invention is relatively simple, easy to implement, and can be integrated into the existing three-piece can production line, with good practicality and economy. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the technical solutions of the embodiments disclosed in the present invention, the drawings of the embodiments will be briefly introduced below. These drawings are only used for illustrative purposes and are not intended to limit the protection scope of the present invention.

[0042] Figure 1 It is a structural schematic diagram of a processing device for a tinplate three-piece can body of the present invention;

[0043] Figure 2 It is a schematic flow chart of a method for processing a tinplate three-piece can body according to the present invention;

[0044] Figure 3 It is a schematic diagram of the welding current of the middle tank of the present invention;

[0045] Figure 4 It is a schematic diagram of the welding current of the edge tank of the present invention. DETAILED DESCRIPTION

[0046] The technical solution of the present invention (including the preferred technical solution) is further described in detail below by means of the accompanying drawings and by listing some optional embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0047] Example 1

[0048] This embodiment provides a processing device for a tinplate three-piece can body, such as Figure 1 As shown, the device includes a slitting roller cutter 1, a slat conveying platform 2, a small piece roller cutter 3, a first conveyor belt 4, a second conveyor belt 5, a turning conveyor belt 6, a middle small piece conveyor belt 7, an edge small piece conveyor belt 8 and a small piece conveyor belt 9.

[0049] The uncoiling and shearing device (not shown in the figure) is used to uncoil the tinplate steel coil and shear the tinplate steel coil into large pieces 10 according to the design size of the can body, and ensure that the height direction of the can body is perpendicular to the rolling direction of the tinplate steel coil, such as Figure 1 As shown;

[0050] The slitting roller cutting machine 1 is used to cut the printed tinned large sheet into 7 rows of strips 11 (i.e. A, B, C, D, E, F, G), and ensure that the shearing direction is parallel to the height direction of the can body, that is, perpendicular to the rolling direction of the steel coil;

[0051] The slat conveying platform 2 is used to convey the slats 11 cut by the slit roller to the small sheet roller cutter 3, and the conveying direction is perpendicular to the height direction of the can body;

[0052] The small-piece roller cutting machine 3 is used to receive the sheet materials conveyed by the slat conveyor 2 and cut each row of the sheet materials into small pieces, and convey the first column of small pieces, i.e. the left side small pieces, such as G1, F1, etc., to the first conveyor belt (i.e. the edge small piece transition conveyor belt 4); convey the seventh column of small pieces, i.e. the right side small pieces, such as G7, F7, etc., to the second conveyor belt 5; convey the remaining small pieces, i.e. the middle small pieces, such as G2-G6, F2-F6, etc., to the middle small piece conveyor belt 7;

[0053] The turning conveyor belt 6 is used to receive the small pieces on the first conveyor belt 4, and rotate them 180° and then transport them to the edge small piece conveyor belt; the turning conveyor belt 6 includes two 90° turning conveyor belts 6.1, which are used to rotate the left side small piece 180°, so that the edge effect of the left side small piece is consistent with the edge effect of the right side small piece, which is convenient for the subsequent use of the same welding process.

[0054] The edge small piece conveyor belt 8 receives the small pieces on the turning conveyor belt 6 and the second conveyor belt 5;

[0055] The middle small piece conveyor belt 7 and the side small piece conveyor belt 8 convey the small pieces thereon to the small piece conveyor belt 9 in different time periods;

[0056] The small-sheet conveyor belt 9 is used to convey the small sheets thereon to a welding machine (not shown in the figure).

[0057] In this embodiment, the welding machine adopts I1 current to weld the incoming materials from the middle small piece conveyor belt, namely: A2-6, B2-B6, C2-C6, D2-D6, E2-E6, F2-F6, G2-G6; adopts I2 current to weld the incoming materials from the edge small piece conveyor belt, namely: A1, B1, C1, D1, E1, F1, G1, A7, B7, C7, D7, E7, F7, G7; wherein I1<I2, such as Figure 3 , Figure 4 shown.

[0058] The small piece conveyor belt 9 transports the incoming materials from the edge small piece conveyor belt 8 and the middle small piece conveyor belt 7 to different welding stations of the same welding machine respectively, and realizes differentiated welding processing of small pieces from different sources by adjusting the welding current parameters of different stations.

[0059] Example 2

[0060] On the basis of Example 1, Figure 2 As shown, this embodiment provides a method for processing a tinplate three-piece can body, and the specific steps are as follows:

[0061] Step 1: Process the steel coil into a large sheet 10, the size of which makes the height direction of the can body perpendicular to the rolling direction of the steel coil, such as Figure 1As shown; this step is usually completed on the production line through uncoiling, shearing and other equipment.

[0062] Step 2: Use a slitting roller cutter 1 to shear the large sheet into strips, and cut the large sheet into 7 rows of strips (A, B, C, D, E, F, G) perpendicular to the rolling direction of the steel coil;

[0063] Step 3: Use a small-sheet roller cutter to process each slat into small sheets;

[0064] Step 4: convey the first row of small pieces (A1, B1, C1, D1, E1, F1, G1) to the turning conveyor 6 through the edge small piece transition conveyor 4, and the turning conveyor 6 rotates them 180° and places them on the edge small piece conveyor 8; place the seventh row of small pieces (A7, B7, C7, D7, E7, F7, G7) directly on the edge small piece conveyor 8; place the remaining small pieces (A2-6, B2-B6, C2-C6, D2-D6, E2-E6, F2-F6, G2-G6) on the middle small piece conveyor 7;

[0065] Step 5: The middle small piece conveyor belt 7 and the side small piece conveyor belt 8 transfer the small pieces thereon to the welding machine through the small piece conveyor belts 9 at different times, and weld them using different welding processes.

[0066] In this embodiment, the welding machine uses I1 current to weld the incoming materials from the middle small-sheet conveyor belt, and uses I2 current to weld the incoming materials from the side small-sheet conveyor belt; I1<I2.

[0067] Through the above method, the left small piece (1 row of small pieces) is rotated 180 degrees and placed on the edge small piece conveyor belt 8 with the right small piece (7 rows of small pieces). The edge effects of the two are consistent and can be processed with the same welding parameters, which simplifies the process flow and improves production efficiency.

[0068] Example 3

[0069] On the basis of Examples 1 and 2, Figure 3 and Figure 4 As shown, this embodiment describes the welding current of the edge small pieces and the middle small pieces.

[0070] The small piece in the middle is made of Figure 3 In the welding with the current shown, there is no "edge effect" in the middle lower piece, and the thickness of the tinning layer and the steel plate are uniform. Generally speaking, the current should remain unchanged throughout the entire weld. However, considering that the two ends of the tank body still need to undergo secondary processing, the connection of the weld is required to be more reliable, and the ends of the weld do not have the cumulative effect of welding heat like the middle part. Therefore, in this embodiment, the welding current is increased by 1 to 5% at both ends of the weld of the small middle piece.

[0071] That is to say, the welding current I3 of the middle part of the weld of the small piece in the middle during welding from t1 to t2 and the welding current I4 of the two end parts of the weld of the small piece in the middle during welding from 0 to t1 and t2 to t3 are increased by 1 to 5% relative to I3.

[0072] The edge small pieces are made of Figure 4 In the current welding shown, there is an "edge effect" at one end of the weld of the small piece at the edge compared to the small piece in the middle, such as Figure 1 Therefore, when welding the edge small pieces, the welding current I5 (t'2~t'3) at the end of the weld with the "edge effect" is increased by 1~5% compared with the welding current I6 (0~t'1) at the other end, and I6 is increased by 1~5% compared with the welding current I7 (t'2~t'3) in the middle part of the edge small piece weld.

[0073] In a specific embodiment of the present invention, for a tin plate with a thickness of 0.18 mm and a tin coating amount of 1.1 / 1.1 g / mm 2 , when the welding speed is 80m / min, the welding pressure is 42kg, and the overlap is 0.42mm.

[0074] The welding current of the small piece in the middle is 3510A in the middle part and 3580A at both ends.

[0075] The welding current of the small pieces at the edge is: 3510A in the middle part, 3580A at one end, and 3680A at the other end due to the "edge effect".

[0076] Example 4

[0077] Based on Example 1, 2 or 3, this embodiment sets two small sheet conveyor belts 9 respectively, and conveys the incoming materials of the edge small sheet conveyor belt 8 and the middle small sheet conveyor belt 7 to two different welding machines respectively. The two welding machines can perform welding operations at the same time, further improving production efficiency.

[0078] Specifically, the first welding machine is used to process the small pieces in the middle, using I1 current for welding; the second welding machine is used to process the small pieces at the edges, using I2 current for welding. In this way, the two types of small pieces can be welded at the same time without the need for time-sharing, further improving production efficiency.

[0079] Those skilled in the art will readily appreciate that the above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, combinations, replacements, improvements, etc. made within the spirit and principles of the present invention are included within the protection scope of the present invention.

Claims

1. A processing device for a tinplate three-piece can body, characterized in that: include: Uncoiling and shearing device uncoils the tinplate coil and cuts it into large sheets according to the design size of the can body, and ensures that the height direction of the can body is perpendicular to the rolling direction of the tinplate coil; Slitting roller cutting machine cuts the printed tinned sheet into N rows of strips, and ensures that the cutting direction is parallel to the height direction of the can body; The slat conveying platform is used to convey the slats cut by the slit roller to the small sheet roller cutting machine, and the conveying direction is perpendicular to the height direction of the can body; The small sheet roller cutting machine is used to receive the sheet conveyed by the slat conveyor and cut each row of sheet into M rows of small sheets, and convey the first row of small sheets to the first conveyor belt, the Mth row of small sheets to the second conveyor belt, and the remaining small sheets to the middle small sheet conveyor belt; The turning conveyor belt is used to receive the small pieces on the first conveyor belt, rotate them 180 degrees and then convey them to the edge small piece conveyor belt; The edge small piece conveyor belt receives the small pieces on the turning conveyor belt and the second conveyor belt; The middle small sheet conveyor belt and the side small sheet conveyor belt convey the small sheets thereon to the small sheet conveyor belt in a time-sharing manner; The small sheet conveyor belt is used to convey the small sheets thereon to the welding machine.

2. The processing device for the tinplate three-piece can body according to claim 1, characterized in that: The welding machine uses I1 current to weld the incoming materials from the middle small piece conveyor belt, and uses I2 current to weld the incoming materials from the side small piece conveyor belt.

3. The processing device for the tinplate three-piece can body according to claim 2, characterized in that: I1<I2.

4. The processing device for the tinplate three-piece can body according to claim 1, characterized in that: The small-piece conveyor belt transports the incoming materials from the edge small-piece conveyor belt and the middle small-piece conveyor belt to different welding machines or different welding stations of the same welding machine.

5. The processing device for the tinplate three-piece can body according to claim 1, characterized in that: The turning conveyor belt comprises two 90° turning conveyor belts spliced ​​into 180°, which are used to rotate the first column of small pieces by 180°.

6. A method for processing a tinplate three-piece can body, characterized in that: include: Processing the steel coil into a large sheet, the size of the large sheet is such that the height direction of the can body is perpendicular to the rolling direction of the steel coil; Using a slitting roller cutter to shear the large sheet into strips, and shearing the large sheet into N rows of strips perpendicular to the rolling direction of the steel coil; Use a small-chip roller cutter to process each strip into M rows of small chips; The first row of small pieces are rotated 180 degrees and placed on the edge small piece conveyor belt together with the Mth row of small pieces, and the remaining small pieces are placed on the middle small piece conveyor belt; The middle small piece conveyor belt and the side small piece conveyor belt convey the small pieces thereon to the welding machine through the small piece conveyor belts at different times, and different welding processes are used for welding.

7. The method for processing the tinplate three-piece can body according to claim 6, characterized in that: The welding machine adopts I1 current to weld the materials from the middle small piece conveyor belt, and adopts I2 current to weld the materials from the side small piece conveyor belt; I1<I2.

8. The method for processing the tinplate three-piece can body according to claim 6, characterized in that: The first row of small pieces are transported to the turning conveyor belt through the first conveyor belt, and the turning conveyor belt rotates them 180 degrees and places them on the edge small piece conveyor belt.

9. The method for processing the tinplate three-piece can body according to claim 6, characterized in that: The Mth row of small pieces are directly placed on the small piece conveyor belt of the edge placement section through the first conveyor belt.

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