JPH02220723A - Method and device for working contraction of can drum - Google Patents

Abstract

PURPOSE:To execute contraction working which scarcely generates a fold and backling by inserting a male die into an opening end of a can drum, fitting a cylindrical female die into the opening end of the can drum, and moving backward the inserted male die at the time when the opening end is converted to a thin diameter. CONSTITUTION:A can drum K is held by a holding mechanism, and a female die 35 is advanced at a speed exceeding it and inserted into the can drum K. When the female die 35 starts to narrow the opening end of the can drum K, a male die 30 is moved backward at a low speed. A part KA converted to a thin diameter of the can drum K is drawn in the extending direction by frictional force working between the part and the outside peripheral surface of the female die 35, and a fold and buckling are scarcely generated. In this contraction working, the male die and the female die are driven simultaneously by using one compounded cam, and brought to relative movement, while holding exactly moving amount and moving speed.

Description

DETAILED DESCRIPTION OF THE INVENTION "Industrial Field of Application" The present invention is directed to the use of a can body that can be used as a can container for soft drinks, etc.
The present invention relates to a processing method and processing device for performing constriction processing.

"Conventional technology" Generally, when manufacturing aluminum cans for soft drinks, etc., the open end of a bottomed cylindrical can body obtained by deep drawing is necked in multiple stages. This reduces the opening diameter and secures the can lid. The reason why this constriction process is performed is to reduce the diameter of can lids, which are expensive due to their thickness, and reduce costs.

Conventionally, when performing this constriction processing, for example, Fig. 8 (a)
The methods shown in ~(d) were adopted.

In the figure, the symbol l is a cylindrical male mold, and 2 is a female mold disposed coaxially with a slight gap around the outer periphery of the male mold 1.
A processed surface 2A for reducing the diameter of the can body is formed on the inner surface of the can body.

In this method, the male fit and the female fit 2 are first advanced simultaneously as shown in (a), and when the male fit has entered the can body a certain length, the male fit l is stopped (b), while the female fit 2 is further advanced. It is moved forward to fit the taber surface 2A into the can body K. As a result, the open end of the can body is gradually reduced in diameter and extends along the outer peripheral surface of the stopped male die 1, forming a narrow diameter part ()
\). When the narrow diameter portion reaches a predetermined length, both the female mold 2 and the male mold 1 are moved back, and the can body K is handed over to the next process (d)
. By repeating this constriction process in multiple stages, multiple constrictions are formed in the can body K, and the diameter is narrowed.

Note that the constriction processing apparatus for carrying out the above method has conventionally been used in a constriction processing mechanism consisting of an inner cylinder and an outer cylinder that slidably support a male mold 1 and a female mold 2, respectively, in which the inner cylinder is connected to the outer cylinder by a spring or the like. A single cam drives only the outer cylinder while it is pressed against the front end of the cylinder, and when the outer cylinder advances a certain distance, a stopper stops only the forward movement of the inner cylinder and moves the outer cylinder to a predetermined position. A mechanism in which the cylinder moves forward to its full length and then retreats together with the inner cylinder, or a configuration in which the male mold 1 and the female mold 2 are each driven by separate drive sources, such as hydraulic cylinders, has been common.

``Problems to be Solved by the Invention'' However, in the above constriction processing method, when the opening end of the can body is reduced in diameter by the female die 2 and extended along the outer peripheral surface of the male die l, this extension A frictional force is generated between the part and the male mold 1 in a direction opposite to the direction of extension, and this frictional force has the disadvantage that wrinkles and buckling tend to occur in the narrow diameter part. For this reason, if the wall thickness of the can body is made thinner or the operating speed is increased, the yield rate tends to deteriorate suddenly, and efforts are being made to reduce costs by thinning the can body and improve productivity by high-speed machining. This was a hindrance.

On the other hand, in a mechanism where the cylinder and outer cylinder are driven by a single cam,
The drawbacks of the above constriction processing method cannot be resolved, and the male die 1
In a mechanism in which the female mold 2 and the female mold 2 are moved by separate drive sources, it is difficult to completely synchronize them and move them relative to each other while maintaining accurate movement amount and speed, resulting in low operating accuracy and reliability of the device. Furthermore, since separate drive sources are provided for each of the male mold 1 and the female mold 2, the structure of the device becomes complicated and the cost increases.

[Means for Solving the Problems] The present invention has been made to solve the above problems.
First, the method of constricting a can body according to the present invention involves moving a male mold previously inserted into the can body in a direction to pull it out from the can body when the female mold is fitted into the open end of the can body to reduce the diameter. It is characterized by

On the other hand, the necking device according to the present invention has a male mold having a smaller diameter than the can body, and a machining surface provided coaxially with the male mold and movable relative to the male mold in the axial direction, and having a machining surface on the inner surface for reducing the diameter of the open end. A cylindrical female mold, a driven member connected to each of the male mold and the female mold, and a cam surface that each of these driven members engages with, and moves the driven member in the axial direction as they rotate relative to each other. The present invention is characterized by comprising a composite cam and a can body holding mechanism capable of holding the can body in a state where the open end of the can body faces the male mold and the female mold.

"Function" In the above necking method, the can body stretches along the outer circumferential surface of the male mold, and at the same time, the male mold moves in the same direction as this stretching direction, so the friction force that pulls the narrow diameter part in the stretching direction , and wrinkles and buckling are less likely to occur in the narrow diameter portion. Therefore, it is possible to use a thinner can body than before and increase processing speed.

On the other hand, according to the constriction processing device, by sliding the driven members along the outer periphery of the composite cam, the male die and the female die are moved relative to each other at a constant cycle while maintaining accurate movement amount and movement speed. Since this is easy, it is possible to implement processing methods that involve complex operations such as those described above, which were difficult to implement with conventional equipment. Furthermore, since the male and female cams can be driven separately, the structure is relatively simple and the cost is low.

``Example'' Hereinafter, an example of the method and apparatus for constricting a can body according to the present invention will be described. For convenience of explanation, the first
The left side of the figure is the front, and the right side is the rear.

FIG. 1 is a longitudinal sectional view showing the constriction processing device. Reference numeral 10 in the figure is a pedestal, on which a rotating shaft 13 is horizontally supported via legs 11 and bearings 12, and the other end passes through the support 1O and is driven at a constant speed by a drive mechanism (not shown). be rotated.

An annular support body 14 is coaxially fixed to the front part of the rotating shaft 13, and can body holding mechanisms 15 are fixed horizontally and at equal intervals in the circumferential direction on the outer periphery of the support body 14. This can body holding mechanism 15 is provided with a rearwardly facing suction cup 16, and air is sucked in from an end surface 16A of the suction cup 16 by a pressure reducing device (not shown).

This end surface 16A has a shape that closely fits the closed end of the can body,
Can body K can be attracted and fixed horizontally by suction. Furthermore, a pair of can body support plates 17 are fixed to the rotating shaft 13 adjacent to the support body 14 and supporting the outer periphery of the can body.

On the other hand, an annular support body 20 is provided on the rear outer periphery of the rotating shaft 13.
are fixed coaxially, and on the outer periphery of this support body 20, a necking mechanism 2 is provided facing each of the can body holding mechanisms 15.
1 is fixed horizontally.

As shown in FIGS. 2 and 3, this constriction processing mechanism 21 includes an outer cylinder 23 supported so as to be slidable back and forth within a cylinder 22 fixed to the outer periphery of a support body 20, and an outer cylinder 23 supported so as to be slidable back and forth. It is mainly composed of an inner cylinder 24 inserted into the front end of the cylinder so as to be slidable back and forth, and a hollow shaft 25 fixed to the rear end of the inner cylinder 24.

A recess 1I1126 is formed in the outer peripheral surface of the outer cylinder 23 in the longitudinal direction, and a parallel key 27 fixed to the support body 20 restricts the forward and backward movement direction. Further, a spring 28 is built in the outer cylinder 23 and urges the hollow shaft 25 and the inner cylinder 24 forward.

Furthermore, three locking claws 29 are attached to the outer peripheral surface of the front end of the outer cylinder 23 at equal intervals in the circumferential direction, as shown in FIG. has been done. The female mold 30 is made of cemented carbide, and has a curved processed surface 30A formed at the front end of its inner peripheral surface to reduce the diameter of the opening end of the can body.

Further, a connecting plate 31 extending rearward is fixed to the rear end of the outer cylinder 23, and a long hole 32 that is long in the front-rear direction is formed in the center of the connecting plate 31. Rollers 33 (driven members) are each rotatably attached toward the shaft 12.

On the other hand, a male mold 35 having a cylindrical shape having the same diameter as the inner diameter after processing into the can body is coaxially fixed to the front end of the inner cylinder 24, and there is a gap between the male mold 35 and the female mold 30, which is about the same as the thickness of the can body. is formed.

Further, on both sides of the rear end of the hollow shaft 25, as shown in FIGS. 4 and 5, openings 36 are formed on both sides of the outer cylinder 23.
A pair of arms 37 are fixed toward the rear through it. A roller mounting plate 38 is provided between the rear ends of these arms 37.
is fixed and is slidable along the upper surface of the connecting plate 31.

A roller 39 (driven member) is rotatably attached to the lower surface of the roller mounting plate 38 through the elongated hole 32 of the connecting plate 31 so as to face the rotating shaft 13 .

Furthermore, a pipe 41 is connected to the rear end of the hollow shaft 25 as shown in FIG. 3, and this pipe 41 is connected to a pressurizing device (not shown) through a long hole 42 formed in the outer cylinder 23. Compressed air is supplied to the male die 35 side through the hollow shaft 25 and the inner cylinder 24 to prevent dents in the can body during necking.

On the other hand, as shown in FIG. 1, a large-diameter compound cam 45 is coaxially disposed on the rear outer periphery of the rotating shaft 13 and is fixed to the base 10 via a cylindrical body 46.

On the outer surface of this composite cam 45, a male cam groove (cam surface) 47 having the same width as the roller 39 is formed at the center in the width direction, and a pair of parallel acid cam surfaces 48 are formed on both sides of the male cam groove. 47, each roller 39 is fitted at equal intervals in the circumferential direction, and each roller 33 is positioned so as to sandwich each acid cam surface 4B. As a result, when the rotating shaft 13 rotates, the male cam groove 47 and the acid cam surface 4
Each row 1F 39.33 moves back and forth following the meandering pattern of 8.

Incidentally, a developed view of the male cam groove 47 and the female cam surface 48 is shown in FIG. As is clear from this figure, the female die 30 moves forward (,
A I ) → Retreat (A2)
)→Backward (B3) and return to the home position.

Further, on both sides of this device, compound cams 4 shown in FIG.
At an angle of 5, between 210 @ and 0 degrees, at a position closer to Oc',
A can body supply device for supplying can bodies K to this device is installed, and a next stage device for receiving and receiving can bodies K that have been processed is installed at a position near 210@ (both are along the paths shown in the figure).

Next, a method of necking a can body using the above-mentioned apparatus will be explained.

First, the can body supply mechanism is operated while rotating the rotary shaft 13 at a constant speed, and the can body K is placed in the can body holding mechanism 15 at the can body supply position.
is passed to the receiver and fixed by suction with the suction cup 16.

When the rotating shaft 13 further rotates, the female die 30 starts moving forward (A1) as shown in FIG. 7(A), and at the same time the male die 3
5 advances (B 1 )L at a higher speed and is inserted into the can body.

Next, as shown in FIG. 7(B), when the female mold 30 begins to narrow the opening end of the can body, the male mold 35 retreats at a low speed (B2).
Start L. Therefore, the reduced diameter portion KA of the can body
is pulled in the direction of extension by the frictional force acting between it and the outer circumferential surface of the male die 35, making it difficult to wrinkle or buckle. In addition, B
The backward speed of the male mold 35 in No. 2 is preferably about 10 to 20% of the forward speed of the female mold 30. If it is less than 10%, a sufficient wrinkle/buckling prevention effect cannot be obtained, and if it is more than 20%, there is a risk that sliding marks or scratches may be produced on the inner surface of the can body.

Eventually, when the length of the narrow diameter part KA reaches a predetermined length, the male mold 3
5 and the female die 30 are both moved back (A2, B3) and pulled out from the can body, and the processed can body is delivered to the next process device at the discharge position, completing one cycle. Thereafter, the same operation is repeated for each constriction processing mechanism 21I.

In the method for constricting a can body having the above configuration, when the narrow diameter portion KA of the can body extends along the outer peripheral surface of the male mold 35, the male mold 35 moves at a low speed in the same direction. A constant frictional force is applied to the diameter portion KA in the direction in which it extends, thereby preventing the occurrence of wrinkles, buckling, etc. Therefore, it is possible to process a can body that is thinner than before without causing a decrease in yield, and by making the can body thinner, it is possible to reduce manufacturing costs. Furthermore, since wrinkles and buckling are less likely to occur in the can body K, it is possible to increase processing speed and improve productivity.

Furthermore, according to this processing device, since the male die 35 and the female die 30 are simultaneously driven using one compound cam 45,
It is easy to completely synchronize these and move them relative to each other while maintaining accurate movement amount and movement speed, and the operation reliability is also extremely high. Therefore, it is possible to perform complex processing methods such as those described above, which were difficult to implement with conventional equipment.
Since there is no need to provide multiple driving sources, the structure is relatively simple and the cost is low.

In this example, while the composite cam 45 is fixed, the plurality of constriction processing mechanisms 21 fixed to the rotating shaft 13 are rotated around the composite cam 45, and each of the male molds 3
5 and the female mold 30 are driven by the composite cam 45,
Compared to a configuration in which the compound cam 45 side is rotated, it is possible to always supply and discharge to the can body at a fixed position, and it is easy to link with the previous and next process equipment. Efforts are being made to improve productivity.

It should be noted that the present invention is not limited to the above-mentioned embodiment, and if necessary, the constriction mechanism (21) side may be fixed while the cam (45) side may be rotated to form the male die (35) and the female die. It may be configured to drive the mold (30), and the details of the device can be changed as appropriate.

"Effects of the Invention" As explained above, according to the method for necking a can body according to the present invention, when the can body is expanded along the outer peripheral surface of the male mold, the male mold is moved and the can body is expanded. Since a frictional force is generated that pulls the narrow diameter portion in the direction of extension, wrinkles, buckling, etc. can be prevented from occurring in the narrow diameter portion. Therefore, even if thin-walled can bodies are constricted than before, wrinkles and buckling are less likely to occur.
By making the wall thinner, manufacturing costs can be reduced. In addition, since wrinkles and buckling are less likely to occur in the can body, processing speed can be increased and productivity can be improved.

Furthermore, according to the can body constriction processing device according to the present invention,
Since a single compound cam is used to drive the male and female dies at the same time, it is easy to synchronize them completely and move them relative to each other while maintaining accurate travel distance and speed, which also increases reliability. Extremely high. Therefore, it is possible to perform processing methods that require complex operations such as those described above, which were difficult to implement with conventional equipment, and since there is no need to provide multiple drive sources, the structure is relatively simple and costs are low. has advantages.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view showing a can body constriction processing apparatus according to the present invention, FIGS. 2 and 3 are left side views and longitudinal cross-sectional views of the constriction mechanism of the same apparatus, and FIG. 4 is a constriction mechanism. 5 is a sectional view taken along the line v-■ in FIG. 4, FIG. 6 is a developed view of the cam, and FIGS. 7 (a) to (d) are explanations of the constriction processing method using this device. It is a diagram. On the other hand, Figure 8 (a)
- (D) are explanatory diagrams of the conventional constriction processing method. K... Can body, lO... Pedestal, 13... Rotating shaft, 1
5... Can body holding mechanism, 21... Constriction processing mechanism, 3
0...Female type, 33...Roller (driven member), 35...
... Male type, 39 ... Roller (driven member), 45 ... Composite cam, 47 ... Male cam groove (cam surface), 48 ... Female cam surface.

Claims (2)

[Claims] (1) A male mold with a smaller diameter than the can body is coaxially inserted into the open end of the can body, and a cylindrical female mold with a machined surface whose inner diameter narrows is fitted onto the outer periphery of the open end. In the method for constricting a can body in which the opening end is narrowed in diameter and extended along the outer circumferential surface of the male die to form a constricted narrow diameter part, the female die is fitted into the open end of the can body. A method for necking a can body, characterized by moving a male mold inserted into the can body in a direction to pull it out from the can body when the can bodies are being fitted together. (2) A male die having a smaller diameter than the open end of the can body, and a cylindrical female die that is coaxial with the male die and movable relative to the axial direction and has a machined surface on the inner surface for reducing the diameter of the open end. and a driven member connected to each of the male and female types, and a composite cam having a cam surface with which these driven members respectively engage, and which moves each driven member in the axial direction as the driven members rotate relative to each other. 1. A can body constriction processing apparatus comprising: a can body holding mechanism capable of holding the can body in a state where the open end of the can body is opposed to the male mold and the female mold.