KR100851220B1 - Three pieces steel can manufacturing method and necking device thereof - Google Patents

Abstract

A three-piece steel can manufacturing method and a necking device used for the same are provided to hold a closed state of a lug cap stably by maintaining the hanging state of a lug over a predetermined section by a lug hanging unit. A three-piece steel can manufacturing method comprises the steps of: coating, printing, and baking steel alloy plates; forming a cylinder-shaped can body(10) by welding both ends of the steel alloy plate; forming a multi-stage neck-in part by repeating a process for forming a neck by inserting the can body into a gap between a ring-shaped insert(120) and a movable centering(114) positioned in an inner diameter part of the insert and forming the other neck on the upper end of the neck by inserting the can body into a gap between the size-reduced insert and movable centering; bending the can body in order to widen the upper and lower ends of the can body toward the outside; protruding plural beads on the outer peripheral surface of the neck; curling the upper end of the can body toward the outer underside; seaming a bottom end to the lower end of the can body; and checking the leakage state of the steel can by a pressure test, spraying paints to remove the damaged and exposed metal part and then baking the can.

Description

Three-piece steel can manufacturing method and necking device used for the same

The present invention relates to a three-piece steel can manufacturing method and a necking device for performing the necking process in the manufacturing method.

A three-piece steel can consists of a cylindrical can body, a bottom end mounted at the bottom of the can body, and a cap mounted at the top of the can body. The cap was previously used only for glass bottles, and has the advantage of sealing (resealing) the container again even after the first container opening, so it is also applied to steel cans.

However, since the outer diameter of the cap is smaller than the outer diameter of the can body of the steel can, in order to enable the cap to be used in the steel can, a neck-in part is formed in the upper portion of the can body, the diameter of which is reduced in stages, so that the cap can be used with the cap. Size must be adjusted.

Also, beads are projected to the neck-in for fastening the cap. The bead includes a big bead and a small bead, a lug cap is used for the big bead, and a PT cap is used for the small bead.

On the other hand, the conventional big bead is a simple straight protrusion is formed to be inclined at a predetermined angle it is not known how much to rotate when closing the lug cap, and the other means for maintaining the combined state even when the lug cap is closed There was a problem that is easily reopened by the external force.

In addition, the small bead has a low width and low degree of protrusion, the lack of bonding strength with the Piticap, there was a problem in that the sealing (lack).

In addition, since the upper end of the body is a sharp metal cross section, it has a good curling property with the compound layer of the cap (prevention of damage of the compound layer) and curling process that is rolled out to protect the lips of the drinker. However, the lack of curling caused the rust to form at the end due to moisture permeated from the outside.

On the other hand, the candies are rolled round steel alloy plate (Blank) round and both ends are welded over (lap) as shown in Fig. 1, the weld portion (W) is a plate material is overlapped in two layers (T) Is increased (1.3 to 1.5 times the single thickness (E) of the steel alloy plate) and high-temperature welding (welding temperature = 950 ° C) increases the strength, and the necking process is repeated. Since the work hardening occurs by simply pushing the canddies into the necking die to form a multi-stage neck, deformation caused by depression and buckling in the weld portion W occurred.

Therefore, in the related art, as in the present applicant's registered patent (Registration No. 10-706264; 3-piece steel can and manufacturing method thereof), the can body is first pushed into a necking die to form a lower neck end, and then the upper part of the can body. Was pushed with a roller to perform a necking process to form the neck end of the desired number.

In other words, in order to form as many necks as necessary for the body, the process using the necking die and the process using the roller must be carried out. Also, since the devices used in each process are also present separately, production time and cost increase. there was.

Therefore, the present invention has been made to solve the above problems, it can be seen that when the lug cap is completely closed, it is possible to maintain a stable state of the lug cap, and the airtightness by Piticap is improved It is an object of the present invention to provide a steel can in which no rust occurs in the curling portion of the upper end.

In addition, it is possible to perform the whole necking process with only one type of device, thereby reducing the man-hour and providing a three-piece steel can manufacturing method and a necking device used therein that can reduce the cost of having all other types of devices. Has its purpose.

Three-piece steel cans according to the present invention for achieving the above object,

A multi-stage neck-in part is formed on the upper part of the body, and a big bead is formed in the upper part of the neck-in part. The big bead is a horizontal straight lug engaging part and a guide inclined upwardly at one end of the lug locking part. And a stopper portion inclined downward at the other end of the lug engaging portion, and a bottom end is mounted at a lower end of the can body.

On the other hand, a multi-stage neck-in part is formed in the upper part of the body, the roll bead protrudes in a ring shape over the entire upper circumferential surface of the neck-in part, and the pin-shaped small bead to the roll bead is connected to the lower end It is formed to be inclined in a state, and the bottom end is mounted at the bottom of the can body.

In addition, the end of the curling portion formed on the upper end of the body is rolled into its own side, the side of the end is in close contact with the upper outer peripheral surface of the can body, the end is spaced apart from the upper outer peripheral surface of the can body.

On the other hand, the three-piece steel can manufacturing method according to the present invention for achieving the above object,

Coating, printing, and baking the steel alloy plate as a raw material of the steel can;

A welding process of welding both ends of the steel alloy plate to form a cylindrical can body;

The can body is inserted between the ring-shaped insert and the movable center ring located at the inner diameter of the insert to form a neck, and then inserted between the insert having the one size reduced and the movable center ring to another top of the neck formed first. A necking process of repeating a process of forming a neck to form a neck-inlet of multiple stages;

A pre-curling / flanging process of bending the upper and lower ends of the candies outwardly;

A bead forming process of protruding a plurality of beads on an outer circumferential surface of the neck;

A final curling process of rolling the upper end of the body outwardly;

Seaming for coupling a bottom end to the bottom of the body;

A post-processing process in which steel cans are leaked through a pressure test and sprayed with a paint spray to remove metal parts damaged and exposed in previous processes;

It is made, including.

The apparatus may further include an expansion molding process for expanding a portion of the body radially outward, and the expansion molding process is performed simultaneously with the bead forming process.

In addition, the extension molding process may be performed between the bead forming process and the final curling process.

On the other hand, the necking device for manufacturing a three-piece steel can according to the present invention performing the necking process of the manufacturing method,

An internal shaft capable of moving forward and backward;

A cylindrical adapter extrapolated to an end of the inner shaft;

A movable center ring radially movable inside the adapter and having an inlet formed in an inclined surface;

An outer shaft having the inner shaft therein and capable of moving forward and backward;

A punch fixed to an end of the outer shaft with an inlet formed as an inclined surface;

An insert formed in an inclined surface inserted into the punch to have a protruding inner diameter surface which abuts against the outer diameter surface of the adapter, the inlet of the protruding inner diameter surface forming a neck-in angle;

A spacer inserted into the punch to support and fix the insert in an axial direction based on the outer shaft;

It is made, including.

According to the present invention, when closing the lug cap in the opening of the top of the body, the final rotation position of the lug cap is limited by the stopper, so that the lug cap can be completely closed, and the lug locking portion lugs over a certain section. The closed state of the lug cap is maintained stably since the locked state of the lug cap is maintained.

In addition, roll beads are present in addition to the small beads, thereby improving the airtightness (sealing property) of the steel can by the Piticap.

In addition, the end of the curling portion formed on the top of the candies are formed to be completely curled into the curling portion to prevent moisture from penetrating the end to prevent the occurrence of rust, the rust water flows or the rust marks on the top of the container By not forming, the hygiene and the appearance of the product are improved.

In addition, according to the present invention, there is provided a manufacturing process capable of manufacturing such a three-piece steel can.

In addition, by using the necking device according to the present invention, when the end portion of the body enters between the insert and the movable center ring, the movable center ring can be inserted freely regardless of the welded position of the body by moving freely in the radial direction. Will be. In other words, when the body is inserted, the movable centering is moved in the opposite direction of the weld to prevent excessive force from being transferred to the weld, thereby preventing the weld from dents and buckling and minimizing the hardening of the work due to the necking repetition. Will be.

Therefore, the use of the necking device allows the entire necking process to be performed with one kind of necking device without having to provide two types of necking devices as in the prior art, thereby reducing the labor and cost in the manufacturing process. There is.

Hereinafter, with reference to the accompanying drawings will be described in detail the present invention.

2 is a front view of a three-piece steel can according to the present invention, wherein the three-piece steel can has a cylindrical can body 10 having a multi-stage neck-in part 11 formed thereon, and the can body ( A bottom end 20 mounted at the bottom of the 10 and a lug cap 30 coupled to the top opening of the can body 10 are included.

The big bead 12 protrudes radially from the surface on the upper circumferential surface of the neck-in part 11 of the can body 10 for coupling the lug cap 30. In addition, the upper end of the can body 10 is formed with a curling part (curing part 13) is rolled out radially outward to protect the compound layer of the lip and the lug cap 30 of the drinker.

The big bead 12 is formed at three to four locations at regular intervals along the outer circumferential surface of the neck-in part 11 (this is equal to the number of lugs 31 formed on the lug cap 30). )

3 is an enlarged view of the big bead 12, wherein the big bead 12 is a predetermined angle upwardly at one end of the lug engaging portion 12a and the lug engaging portion 12a formed in a horizontal straight line shape. It consists of the inclined guide part 12b and the stopper part 12c inclined downward by the predetermined angle at the other end of the lug engaging part 12a.

The guide portion 12b and the stopper portion 12c are formed with the same inclination angle α, and the ends thereof are formed in a semicircular shape.

Therefore, when the lug cap 30 is closed, the lug 31 is guided smoothly to the lower side of the lug engaging portion 12a along the guide portion 12b, and then proceeds along the lower side of the lug engaging portion 12b. The stopper part 12c is caught.

Therefore, when the drinker closes the lug cap 30 again after opening the steel can, the lug 31 feels to be caught by the stopper part 12c, so that the lug cap 30 is completely closed.

In addition, in the state where the lug 31 is in contact with the stopper portion 12c as described above, the lug 31 is pressed downward by the lug catching portion 12b, and thus it is impossible to immediately open upward. In addition, since the lug engaging portion 12b is formed to extend in a horizontal straight line shape for a predetermined section along the circumferential direction, the lug 31 is not rotated in a reverse direction to a position completely out of the forming section of the lug engaging portion 12b. Otherwise, since the lug cap 30 cannot be opened, the closed state is still maintained even when the lug cap 30 is reversely rotated to a short length by an external force applied in a general storage state.

That is, the closed state of the lug cap 30 is kept very stable.

4 shows a steel can for the Piticap 40 according to the present invention. In this case, the roll bead 14a protrudes in a ring shape over the entire outer circumferential surface of the neck-in part 11 of the body 10, and the pin-shaped small bead 14b thinning on the roll bead 14a is formed. It is formed to be inclined with the bottom connected.

Therefore, when the PTI cap 40 is closed in the upper opening of the body 10, the roll bead 14a as well as the small bead 14b may press / deform the compound layer inside the PTI cap 40. Because of the close contact, the bonding force of the Piticap 40 is improved, thereby further improving the airtightness (sealing property) of the steel can.

On the other hand, the curling portion 13 formed on the upper end of the three-piece steel can according to the present invention, as shown in Figure 5, the end of the body 10, that is, the end 13c of the curling portion 13 Is completely rolled into its inner side, and the side surface of the end 13c is in close contact with the upper outer peripheral surface of the body 10, and the end 13c is spaced apart from the upper outer peripheral surface of the body 10 of the curling part 13. It is characterized in that floating in the interior space.

As described above, the end portion 13c having the metal surface exposed is completely located inside the curling portion 13 and is not exposed to the outside, thereby preventing contact with moisture so that rust does not occur. The absence of rust on the part improves hygiene and aesthetics.

Even if a small amount of moisture penetrates between the side surface of the end portion 13c and the contact surface of the upper peripheral surface of the top of the body 10 and rust occurs in the end portion 13c, the formed rust powder or green water is formed inside the curling portion 13. Since it falls to the bottom and can not flow out of the curling portion 13, the traces of rust is completely prevented from appearing outside the steel can.

At this time, the coating may be sprayed and then baked to remove the exposed metal part of the curling part 13 end 13c.

6 is a process diagram of a three-piece steel can manufacturing method according to the present invention, first, the coating (printing) and printing (baking) the steel alloy plate as a raw material of the steel can in the pre-processing process (S10) An intermediate material for manufacturing the body 10 is prepared.

The steel alloy plate (blank) of the square prepared through the pre-processing process (S10) is rolled round in a cylindrical shape and overlaps both ends and welded to produce a can body (welding process (S20)).

At this time, the width that overlaps the both ends of the steel alloy plate, that is, the overlap size (overlap size; same as the width of the weld portion (W)) of the conventional 0.50 ~ 0.60mm to 0.45mm (minimum amount of overlap for producing a normal body) To reduce the thickness (T) of the weld (W) after welding, and to minimize the strength of the current supplied for welding to minimize the increase in strength due to high heat welding (usually, as the amount of overlap increases, the weld is increased). Increases in thickness.)

Subsequently, the candies 10 are supplied to the first stage necking device to form the first stage neck. After the first stage neck is formed, the body 10 is supplied to the two-stage necking device to form a two-stage neck having a smaller inner diameter at the upper end of the one-stage neck. Thereafter, the body is supplied to the three-stage necking device to form a three-stage neck having a smaller inner diameter on the upper portion of the two-stage neck. In this manner, the necking is repeated to the desired number of stages to form a neck-in part 11 formed of a plurality of stages on the top of the body 10 (necking process (S30)).

At this time, the body 10 is inserted between the insert and the movable center ring of the necking device (the device configuration will be described in detail later), and a neck is formed, in which the movable center ring can move freely in the radial direction from the inner diameter of the insert. The welding center W is moved in correspondence with the welding portion W regardless of the circumferential position of the welding portion W (the two ends of the steel alloy plate are overlapped and welded). It is possible to easily enter, and even when the cand 10 is pressed to form a neck, excessive force is not transmitted to the weld W, thereby preventing the weld W from being recessed or buckled.

Therefore, as shown in the drawing, a multi-stage neck ranging from 5 to 9 stages can be formed without deformation of the weld portion (W).

On the other hand, in the necking process of the last step in the necking process (S30) can be necked at the same time as well as the top of the body (10). This is possible by the necking device described later. The necking performed on the lower part of the body 10 can also arbitrarily select the number of stages, thereby reducing the diameter of the bottom end 20, thereby reducing material consumption and removing the flat shape of the lower part of the steel can. To be beautiful. However, in order to secure the upright stability of the steel can, it is not preferable that the lower diameter is excessively reduced, so that only one or two stages are usually formed. Therefore, for example, if the necking process of the nine stages is carried out at the same time the necking of the lower portion in the nine stages or eight to nine stages.

Subsequently, in the necking process (S30), a pre-curling / flanging process of bending the upper and lower ends of the canned body 10 in which the multi-stage neck-in part 11 is formed to open outwardly (pre curing / flanging process; S40) ).

Next, a bead is formed to couple the cap to the upper part of the body 10 (exactly, the upper part of the neck-in part 11). (Bead forming process (S50))

In the bead forming process (S50), as shown, the roll bead 14a and the small bead 14b for the big bead 12 or the pitcap 40 for the lug cap 30 according to the type of the cap to be applied ).

Among them, when forming the roll bead 14a and the small bead 14b, first, the ring-shaped roll bead 14a is protruded radially outward from the surface on the entire outer circumferential surface of the upper part of the neck-in part 11. Subsequently, a plurality of small beads 14a are formed to be inclined at regular intervals in a state where the lower ends are connected to the roll beads 14a.

After the bead formation is completed as described above by curling the pre-curl portion of the upper end of the body can be bent to the end (13c) of the top of the canned body 10 that was bent outward in the pre-curling / flanged process (S40) Final curing process (S60) to complete the curling unit 13 is performed.

In addition, a seaming process (S70) of connecting the two by overlapping the flange portion formed at the lower end of the body 10 and the bottom end 20 is performed.

Finally, after fabricating the steel can by performing the seaming process (S70), a pressure test is performed to check whether there is a leak in the container, and the necking process (S30) and the pre-curling / flanging process (S40). ) And after the bead forming process (S50), the surface of the can is damaged to perform a post-processing process (S80) of spraying and baking the coating to remove the exposed metal parts.

On the other hand, during the necking process (S30) between the pre-necking process and the post-necking process by applying a lubricating oil (edible lubricating oil) to the outer peripheral surface of the neck-inlet 11 of the body 10 By making slip property favorable, processing can be made easy.

In addition, at this time, by reducing the injection angle of the nozzle for injecting the lubricating oil, the lubricating oil may be applied only to the portion to be necked in the post-necking process. The adjustment of the injection angle is adjusted by changing the shape of the injection hole, which is a general technique of the industry, so detailed description thereof will be omitted.

On the other hand, when forming the neck of the stage in the necking process (S30) to reduce the neck pitch (P) and neck-in angle (θ) of each stage to prevent the buckling and depression deformation of the weld (W).

That is, when the neck pitch P exceeds 22 times the thickness of the material (the steel alloy plate), the depth (up and down length) of the entire neck-indentation 11 is excessively increased to easily cause buckling and depression during necking. do. Conversely, if the neck pitch P is less than 18 times the thickness of the material, the number of stages of the neck-in 11 is excessively increased (increasing the number of required processes) in order to obtain the required depth of the neck-in 11.

Therefore, the neck pitch P is preferably formed in the range of 18 to 22 times the material thickness.

In addition, if the neck-in angle θ of one stage is less than 25 °, the necking amount (length of diameter reduction, that is, radially decreasing length) is insufficient, making it difficult to fit the cap size (single stage If greater than 30 °, the deformation amount of one stage is excessive and buckling and depression deformation easily occur.

Therefore, the neck-in angle (θ) is preferably formed in the range of 25 ° ~ 30 °.

As described above, when the neck pitch P and the neck-in angle θ of one stage are reduced, the deformation force due to the pressing force during necking decreases (that is, the counter force increases), thereby preventing depression and buckling deformation.

On the other hand, after the welding process (S20), when the canned body 10 is supplied to the necking device for the first stage necking process of the necking process (S30) when the welding portion (W) of the welding part (tail part) Allow the top of the can to form. That is, the multi-stage necking and curling is performed on the welded portion so that the drinking portion is formed. This is because the high temperature welding is performed while the lead part is supplied with a large amount of current for a longer time than the tail part, and the strength is high, whereas the neck part 11 at the end of the relatively weak weld is finished. This is to prevent the deformation, such as dents, buckling during necking.

In addition, the paint sprayed to cover the exposed metal part in the post-processing process (S80) is sprayed on both the inner circumferential surface and the outer circumferential surface of the neck-in part 11, the bead forming portion, and the curling portion, as shown in FIG. To this end, dedicated nozzles N1 and N2 of the inner and outer circumferential surfaces are provided.

The nozzles N1 and N2 are fixed at a predetermined position, and the can body 10 is rotated so that paint is applied to the entire inner and outer circumferential surfaces. After the coating is applied in this manner, the coating is cured and fixed to the surface of the body through a baking step so that the metal exposed portion does not exist.

On the other hand, the manufacturing method according to the present invention further includes an expansion molding process (S50 ') for manufacturing a release can such as shown in FIG.

An example of the release can is shown in FIG. 9. The illustrated can is shown in the upper portion (the lower portion of the neck-in 11) and the lower portion of the can 10 is convex protruding radially outward to form an expansion projection 16, the upper and lower expansion projections 16 The part between them is formed in a shape connected to a smooth curved surface or a straight line with a gentle inclination angle.

Changing the outer circumferential surface shape of the can body 10 as described above is to improve the appearance of the product and to improve the differentiation from other products to stimulate the consumer's desire to buy, and also can by hand There is also a non-slip effect to prevent slipping when you hold the.

The expanding molding process (S50 ') forming the release can as described above inserts a plurality of dividing molds having a cross-sectional shape to be expanded into the interior of the can 10, and divides the dividing molds into the can bodies (10). By simultaneous expansion (movement) from the inside to the outside in the radial direction.

As shown in FIG. 8, the expansion molding process S50 ′ may be performed simultaneously with the bead formation process S50. When the bead forming process (S50) consists of a plurality of processes, it is preferable to perform the expansion molding process (S50 ') in the last process.

That is, when the big bead 12 is formed in the neck-in part 11 of the body 10, the expansion protrusions 16 are formed at the same time as the big bead 12 is formed, and the roll bead 14a and the small bead are formed. In forming the 14b, the roll bead 14a is first formed, and then the small bead 14b is formed and the expansion protrusion 16 is formed.

In addition, as described above, the expansion molding process S50 ′ may be performed after the bead forming process 50 is not performed simultaneously with the bead forming process 50. That is, the expansion molding process S50 ′ is performed after the bead formation process 50 ends and between the final curling process S60.

As described above, according to the manufacturing method according to the present invention, when performing the necking process (S30), it is possible to form all the stages of the multi-stage neck-inlet using one kind of necking device, thereby reducing labor and cost.

The above-described effect is possible by the necking device to be described below, and also overlaps at both ends when the steel alloy plate is rolled and welded in a cylindrical shape so as to minimize the occurrence of work hardening during the necking process (S30). It is more easily achieved by reducing the size and reducing the strength of the welding current.

Now, the necking device according to the present invention for performing the necking process (S30) will be described.

Figure 10 is a cross-sectional view of the necking device according to the present invention, Figure 11 is an enlarged cross-sectional view of the necking tool portion which is the end portion of the candock is inserted into the actual neck, Figure 12 is a part of the movable center ring which is a configuration of the necking tool It is an enlarged view.

The inner shaft 110 located at the center of the device is installed to be forward and backward by a predetermined drive means.

A cylindrical adapter 112 is extrapolated to the end of the inner shaft 110. (A groove is formed in the center of one side of the adapter, and the end of the inner shaft is inserted into the groove.).

The movable center ring 114 is mounted in the adapter 112 so as to be able to move freely in the radial direction. The movable center ring 114 has a stepped outer circumferential surface with a large diameter portion 114a and a small diameter portion 114b, and an end portion of the small diameter portion 114b is bent toward an axis center to form a bent end portion 114c. . The adapter 112 side surfaces of the large diameter portion 114a and the small diameter portion 114b are in contact with the bottom surface of the inlet side and the inner diameter of the adapter 112, respectively.

Therefore, after inserting the small diameter portion 114b of the movable center ring 114 into the inner diameter portion of the adapter 112, the disc shaped spacer 124 is inserted into the inner diameter portion of the movable center ring 114, and the spacer ( When the bolt 126 is fastened to the inner shaft 110 through the adapter 124 and the adapter 112, the bent end 114c is pressed by the spacer 124 to fix the movable center ring 114 in the axial direction.

In addition, a clearance C1 is formed between an inner diameter surface of the adapter 112 and an outer diameter surface of the small diameter portion 114b of the movable center ring 114, and an inner diameter surface of the movable center ring 114 and the spacer 124. A gap C2 is formed between the outer diameter surfaces of the movable center ring 114 so that the movable center ring 114 can flow radially in the adapter 112.

In addition, the outer diameter surface of the large diameter portion 114a of the movable center ring 114 is formed to have a diameter in which the can body 10 can be inserted between the insert 120.

In addition, the outer diameter surface of the large diameter portion 114a of the movable center ring 114 is formed with an inclined surface 114aa having a relatively large inclination angle, and the tapered surface with a gentle inclination angle β that is continuous with the inclined surface 114aa. 114ab is formed, and a short section behind the tapered surface 114ab is formed as a straight surface 114ac.

On the other hand, the outer shaft 116 in which the inner shaft 110 is built is also installed to be able to move forward and backward by a predetermined drive means. Since it is easily configurable using conventional techniques, it will not be described in detail.)

A cylindrical punch 118 is fixed to the end of the outer shaft 116 via a bolt 128 fastened at regular intervals in the circumferential direction, and a ring-shaped insert 120 is formed inside the punch 118. Spacer 122 is provided. An inclined surface 118a is also formed at the inlet portion of the punch 118.

The insert 120 is pre-inserted into the inner diameter portion of the punch 118 (the portion into which the body 10 enters), and then the spacer 122 is inserted, and in this state, the punch 118 is externally inserted. The bolt 128 is attached to the shaft 116 to maintain a fixed state. That is, the insert 120 is axially supported and fixed by the spacer 122 supported by the cross section of the outer shaft 116.

On the other hand, the inner diameter surface of the insert 120 is formed with a protruding inner diameter surface (120a) that is in contact with the outer diameter surface of the adapter 112, the inlet of the protruding inner diameter surface (120a) is an inclined surface forming a neck-in angle ( 120b). Of course, there is a gap between the protruding inner diameter surface 120a of the insert 120 and the large diameter portion 114a of the movable center ring 114 in which the can body 10 is inserted.

Figures 13 and 14 show the state before and after the necking of the necking device of the present invention, respectively.

Although the necking device having the same configuration is arranged on both coaxial lines around the turret (T), when the necking is performed on only one side of the body 10, one of both necking tools is for simple pressurization. Can be replaced with a punch.

That is, in the step of not performing simultaneous necking on the upper and lower portions of the body 10 in the aforementioned necking process (S30), one of the necking tools is replaced with a simple pressing punch as described above, and the process proceeds.

First, the process of necking only the upper portion of the body 10 in the process progress order will be described.

As shown in FIG. 13, the can body 10 manufactured in the welding process S20 is inserted into a necking device on which the necking of the multi-stage is to be made by the turret T, and a tail part is welded.

In this case, the movable center ring 114 protrudes out of the punch 118.

In the above state, the inner shaft 110 and the outer shaft 116 advance simultaneously, and the movable centering 114 first enters the inside of the body 10 to support the body 10, and in that state the outer shaft 116 is further advanced to allow the end of can body 10 to enter into the gap between movable center ring 114 and punch 118.

Subsequently, when the outer shaft 116 is further advanced so that the end portion of the body 10 contacts the inclined surface 120b of the insert 120, the end portion of the body 10 is bent inward in the radial direction, and the outer shaft ( As the 116 is further advanced, the bent end enters into the gap between the movable center ring 114 and the protruding inner diameter surface 120a of the insert 120 and deforms into a straight line shape. Therefore, a portion of the insert shaft 120 in contact with the inclined surface 120b of the insert 120 protruding inner diameter surface 120a is stopped at the same angle as the inclined surface 120b when the forward movement of the outer shaft 14 is stopped.

As described above, when the necking is made in one side of the necking device, the necking action is assisted by the continuous pressurization by a simple pressing punch in the other necking device.

Next, a necking device having a necking tool whose size is gradually reduced in size (the outer diameter of the adapter 112 and the movable center ring 114 and the inner diameter of the punch 118 and the insert 120 and the inner diameter surface 120a of the insert 120 are reduced). The can 10 is sequentially supplied with a furnace to form as many neck-inches as necessary.

Then, in the last or the last two steps, as shown in Figs. 13 and 14, the necking device capable of necking is arranged on both sides, and the necking process is performed while pressing toward the center in the same manner on both sides. Make the required number of necks at the top and bottom of the head). At this time, the action of the necking tool according to the movement of the inner shaft 110 and the outer shaft 116 is made the same in both.

On the other hand, in the multi-stage necking process as described above, the movable center ring 114 is moved in the radial direction according to the direction of the force applied by the body 10 when entering the inside of the body (10). Done.

In addition, when the end portion of the body 10 enters between the movable center ring 114 and the insert 120, the gap of the corresponding position is opened by the welding portion W of the body 10 and is opposite to the radial direction. Will be moved to.

Accordingly, not only the coupling between the body 10 and the necking tool can be easily performed, but also excessive force is not transmitted to the welding portion W at the time of neck formation, thereby preventing the dent and buckling deformation of the welding portion W. In addition, the degree of work hardening can be minimized.

In addition, since the inlet portion of the large diameter portion 114a is formed as the inclined surface 114aa, the movable center ring 114 is easily guided when entering the inside of the body 10 because it serves as a guide. The same action is also performed in the inclined surface 118a formed at the inlet of the punch 118.

In addition, the tapered surface 114ab successively formed on the inclined surface 114aa in the movable center ring 114 is not in surface contact when the end portion of the body 10 enters, thereby reducing friction, thereby reducing friction. By doing so, the neck-in deformation is easily made, thereby less work hardening due to the deformation.

In addition, since the lubricant is applied to the outer circumferential surface of the portion to be necked in the necking process of each stage as described above, the entry along the inner circumferential surfaces of the punch 118 and the insert 120 (particularly, their inclined surfaces 118a and 120b). And molding is made easier.

By using the necking device according to the present invention as described above it is possible to easily form a multi-stage neck-in part 11 without minimizing the work hardening and dents or buckling deformation. In addition, it is possible to form the entire neck as one type of necking device without having to change the type of necking device, thereby reducing the production time and cost. (However, the necking tool provided in each necking device is for each necking step. Consists of parts with size)

1 is a cross-sectional view of the welded portion of the body,

2 is a front view of a three-piece steel can formed with a big bead according to the present invention;

3 is an enlarged view of the big bead,

4 is a front view of a three-piece steel can formed with roll beads and small beads according to the present invention;

5 is an enlarged view of a curling unit;

6 is a process chart of a three-piece steel can manufacturing method according to the present invention,

7 is a view showing a spraying paint in the manufacturing process of a three-piece steel can,

8 is a process diagram of a state in which an expansion molding process is added to the manufacturing method of FIG. 6;

9 is an exemplary view of a release can formed by the expansion molding process;

10 is a cross-sectional view of the necking device according to the invention,

11 is an enlarged view of a necking tool of the necking device according to the present invention;

12 is a partially enlarged view of a large diameter portion of a movable center ring that is one configuration of the necking tool;

Figure 13 is a state before necking of the necking device according to the present invention,

Figure 14 is a state diagram after the necking of the necking device according to the present invention.

* Description of the symbols for the main parts of the drawings *

10: body 11: neck-worker

12: big bead 12a: lug catching part

12b: guide part 12c: stopper part

13 curling portion 13c: end

14a: Roll Bead 14b: Small Bead

16: expansion protrusion 20: bottom end

30: lug cap 40: Piticap

110: internal shaft 112: adapter

114: operation centering 114a: large diameter part

114aa: sloped surface 114ab: tapered surface

114ac: straight surface 114b: small diameter part

114c: bend end 116: outer axis

118: punch 118a: inclined surface

120: insert 120a: projecting inner diameter surface

120b: slope 122,124: spacer

126,128: Bolt C1, C2: Clearance

T: Turret

Claims (10)

delete delete A pre-processing step of coating, printing, and baking the steel alloy plate as a raw material of the steel can (S10); A welding process (S20) of forming a cylindrical body (10) by welding both ends of the steel alloy plate; The cand 10 is inserted between the ring-shaped insert 120 and the movable center ring 114 located in the inner diameter of the insert 120 to form a neck, and then the insert 120 having a size reduced by one step. And a necking process (S30) of forming a plurality of neck-inches 11 by repeating a process of forming another neck on the upper end of the first formed neck by inserting between the movable centering 114 and; A pre-curling / flanging process of bending the upper and lower ends of the body body 10 outwardly (S40); A bead forming process (S50) for protruding a plurality of beads on an outer circumferential surface of the neck; Final curling process (S60) for rolling the upper end of the body 10 to the outside downward; Seaming process (S70) for coupling the bottom end 20 to the bottom of the body (10); A post-processing process (S80) of spraying paint and spraying a paint to check for leaks of steel cans through a pressure test and to remove metal parts damaged and exposed in previous processes; Three-piece steel can manufacturing method comprising a. The method of claim 3, further comprising an expansion molding process (S50 ') for expanding a portion of the body (10) radially outward, wherein the expansion molding process (S50') and the bead forming process (S50) and A three-piece steel can manufacturing method characterized in that carried out at the same time. The method of claim 3, further comprising an expansion molding process (S50 ') for expanding a portion of the body (10) radially outward, wherein the expansion molding process (S50') and the bead forming process (S50) and Method of producing a three-piece steel can, characterized in that performed between the final curling process (S60). The neck pitch P of each end of the neck-in part 11 is formed in a range of 18 to 22 times the thickness of the material, and the neck-in angle θ is 25 °. Method for producing a three-piece steel can, characterized in that formed in a 30 ° range. The method of manufacturing a three-piece steel can according to claim 3, wherein a multi-stage neck-in part (11) is formed at a welded tail part of the can body (10) in the necking process (S30). An internal shaft 110 capable of moving forward and backward; A cylindrical adapter 112 extrapolated to an end of the inner shaft 110; A movable center ring (114) movably mounted radially inside the adapter (112) and having an inlet at an inclined surface (114aa); An outer shaft 116 in which the inner shaft 110 is embedded and capable of advancing forward and backward; A punch 118 fixed to the end of the outer shaft 116 with a bolt 128 and formed with an inclined surface 118a; An inclined surface 120b inserted into the punch 118 and having a protruding inner diameter surface 120a contacting the outer diameter surface of the adapter 112 and forming an angle at which the inlet of the protruding inner diameter surface 120a is neck-in; Insert 120 formed as; A spacer 122 inserted into the punch 118 to support and fix the insert 120 in the axial direction based on the outer shaft 116; Necking device for manufacturing three-piece steel can comprising a. The method according to claim 8, wherein the movable center ring 114 is stepped into a large diameter portion 114a and a small diameter portion 114b, a bent end portion 114c toward the axis center is formed at the end of the small diameter portion 114b, The spacer 124 covering the bent end portion 114c is inserted into the inner diameter of the movable center ring 114 while the small diameter portion 114b is inserted into the inner diameter portion of the adapter 112. The bolt 126 is fastened to the inner shaft 110 through the adapter 112, and the gap C1 is between the inner diameter surface of the adapter 112 and the outer diameter surface of the small diameter portion 114b of the movable center ring 114. Is formed, and a gap (C2) is formed between the inner diameter surface of the movable center ring (114) and the outer diameter surface of the spacer (124) necking device for manufacturing a three-piece steel can. The method according to claim 8, wherein the inclined surface (114aa) is formed on the outer diameter surface of the large diameter portion (114a) of the movable center ring 114, is connected to the inclined surface (114aa) to form a tapered surface (114ab), the tapered surface ( The rear end of 114ab) is a necking device for manufacturing three-piece steel can, characterized in that formed by a short straight surface (114ac).

Images