Tank manufacturing method and device

Abstract

The present invention addresses the problem of providing an air-assisted method for manufacturing a can, whereby a punch can be smoothly pulled out from a processed can by appropriately performing air assistance. A method for manufacturing a can using a drawing process and / or a drawing reduction process using a press, the method being characterized by having a mold release step for pulling out a punch from a can after the drawing process and / or the drawing reduction process, in the mold release step, the punch is removed from the can after the drawing process and / or the drawing reduction process, and the punch is removed from the can after the drawing process and / or the drawing reduction process. In the air-assisted operation, air is blown out from an air outlet at the tip of the punch to assist the extraction of the punch, and during each impact, the pressure of the air and / or the blow-out timing of the air is adjusted to a pressure and / or a blow-out timing corresponding to the condition of the impact, and the pressure and / or the blow-out timing of the air are / is adjusted to a pressure and / or a blow-out timing corresponding to the condition of the impact.

Description

Technical Field

[0001] The present invention relates to a method and apparatus for manufacturing a metal can by using a drawing process and / or a drawing ironing process using a press machine. Background Art

[0002] Conventionally, the following technology is known: in the deep drawing of a metal can using a punching machine, after the metal can is deep drawn and / or ironed, in order to reduce the negative pressure generated between the bottom of the can and the front end of the punch when the punch is pulled out of the can, air assist is performed to supply auxiliary air to the space between the front end of the punch and the bottom of the can. (See Patent Documents 1 to 3)

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2021-70034

[0006] Patent Document 2: Japanese Patent Application Laid-Open No. 9-271870

[0007] Patent Document 3: Japanese Patent Application No. 2019-525844 Summary of the invention

[0008] Problems to be solved by the invention

[0009] When a metal can is manufactured by deep drawing using a stamping machine, after the metal can is deep drawn and / or thinned using a punch, when the punch is pulled out from the can, the processed can and the punch are in close contact, and the punch is pulled out at a fast speed, so negative pressure is generated in the space between the bottom of the can and the front end of the punch, making it impossible to pull the punch out of the can. Therefore, although the can is pressed by a demolding device to pull out the punch, the negative pressure generated in the space between the bottom of the can and the front end of the punch cannot be eliminated. Therefore, air assistance is performed to eliminate the negative pressure by blowing air from the front end of the punch so that the punch can be pulled out smoothly. (Refer to Figure 1 )

[0010] However, if the air is not blown properly, the punch may not be pulled out normally. For example, if the air is blown weakly, the negative pressure generated in the space between the bottom of the can and the front end of the punch may not be eliminated, and the can may be crushed (see Figure 4 (a)), or, on the contrary, if the air is blown out strongly, the can may be blown away while the punch is pulled out, thereby colliding with surrounding structures such as the die head (see Figure 4 (b)).

[0011] The present invention is proposed to solve the problem that the punch cannot be pulled out normally sometimes. The technical problem is to provide a method and device for manufacturing a can with air assistance, which can smoothly pull out the punch from the processed can by appropriately performing air assistance.

[0012] Solutions for solving problems

[0013] In order to solve the above-mentioned problems, the method for manufacturing a tank according to the present invention has the following configuration.

[0014] A method for manufacturing a can, utilizing a deep drawing process and / or a deep drawing ironing process using a punching machine, wherein the method for manufacturing the can is characterized in that it comprises a demolding process for extracting a punch from the can after the deep drawing process and / or the deep drawing ironing process, wherein in the demolding process, air is blown out from an air blowing port at the front end of the punch to assist in the extraction of the punch by air assistance, wherein in the air assistance, the pressure of the air and / or the blowing time of the air are adjusted to a pressure and / or blowing time corresponding to the conditions of the shot at each shot.

[0015] Furthermore, the can manufacturing apparatus of the present invention has the following configuration.

[0016] A can manufacturing device that utilizes deep drawing and / or deep drawing ironing. The can manufacturing device is characterized in that it comprises: a punch, a demolding device, and a control device. The punch has an air blowing outlet for blowing out air at the front end. When the control device engages the demolding device with the end of the can and pulls out the punch from the can, the air blowing control is performed to blow out air from the air blowing outlet. In the air blowing control, the pressure of the air and / or the blowing time of the air are adjusted to the pressure and / or blowing time corresponding to the conditions of the impact at each impact.

[0017] Effects of the Invention

[0018] The present invention can provide a can manufacturing method and apparatus, which can smoothly extract a punch from a processed can by appropriately adjusting the air pressure and / or the air blowing timing in air assist. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a diagram for explaining air assist in the embodiment of the present invention.

[0020] Figure 2 It is a diagram showing an example of setting the air pressure in a press machine as an embodiment of the present invention.

[0021] Figure 3 1 is a diagram showing an example of setting the timing of blowing air in a press machine as an embodiment of the present invention. Figure 3(a) is a table of time correction values, Figure 3 (b) is its graph.

[0022] Figure 4 This is a diagram for explaining the problem of the present invention. DETAILED DESCRIPTION

[0023] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In the following description, the same reference numerals in different drawings represent parts with the same functions, and repeated descriptions in the drawings will be appropriately omitted.

[0024] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0025] [Implementation Method]

[0026] Hereinafter, the can manufactured by the deep drawing and / or deep ironing process using a stamping machine in the present embodiment is, for example, an aluminum or steel can mainly used for beverage cans, etc., which is called a so-called DI can or a resin-coated can. The can is formed by using a can body manufacturing machine (original Japanese: body ironing machine) as a stamping machine to form an intermediate processed product formed into a cup shape into a can by deep ironing process.

[0027] [Air Assist]

[0028] Figure 1 This is a diagram for explaining air assist in the mold release step in the present embodiment.

[0029] In the can body manufacturing machine, the punch 2 and a plurality of dies (dies not shown) are used to perform a deep drawing and ironing process on the intermediate processed product formed into a cup shape, and finally the shape of the can bottom 11 is formed. This is a known technology also recorded in Patent Documents 1 to 3.

[0030] Figure 1 (a) shows a state where the can 1 is formed by the punch 2 .

[0031] After the molding of the can 1 is completed, a demolding step is performed to remove the punch from the processed can.

[0032] like Figure 1 As shown in (b), after the can 1 is formed, the punch 2 is pulled out from the can 1, but the outer surface of the punch 2 is almost in close contact with the inner surface of the can 1, and the air 5 is not supplied to the space 4 between the can bottom 11 and the punch front end 21, so when the punch 2 is pulled, the can 1 also moves with the punch 2. Then, the upper end of the can 1 is engaged with the demolding device 3.

[0033] like Figure 1As shown in (c), when the upper end of the can 1 is engaged with the demolding device 3, the can 1 is fixed, so the punch 2 is pulled out from the can 1. At this time, air 5 is blown out from the air blowing port 22 provided at the front end 21 of the punch, and the air 5 is supplied to the space 4 between the bottom 11 of the can and the front end 21 of the punch, so as to assist the pulling out of the punch 2. Therefore, no negative pressure is generated between the bottom 11 of the can and the front end 21 of the punch, and the punch 2 is pulled out from the can 1 by the action of the demolding device 3.

[0034] Then, if Figure 1 As shown in (d), the punch 2 is pulled out from the tank 1 and the blowing of the air 5 is also stopped.

[0035] [Air blowing control (operating speed)]

[0036] If the blown air 5 is not blown out at the right pressure and at the right time, the following will occur: Figure 4 (a) and Figure 4 In order to solve the problem shown in (b), in the air assist, during the blowing of the air, the air blowing control is performed by controlling the pressure of the air and the blowing timing by the control device.

[0037] Furthermore, generally speaking, a can body manufacturing machine for molding a can does not always operate at a constant speed, and the operating speed varies depending on various conditions and the like for the can to be manufactured.

[0038] Even when manufacturing a specific tank, the control device controls the manufacturing to be carried out at a slow operating speed at the beginning, gradually increase the operating speed, and when reaching a specified operating speed, continue to operate at the specified operating speed.

[0039] In addition, even in the continuous operation state, the can body manufacturing machine may be operated by appropriately accelerating or decelerating the operating speed according to the operating conditions of the downstream process.

[0040] At a slow operating speed, the punch 2 is pulled out of the can 1 at a slow speed, and at a fast operating speed, the punch 2 is pulled out of the can 1 at a fast speed. In this way, the speed at which the space 4 between the can bottom 11 and the punch tip 21 expands is also slow at a slow operating speed, and is also fast at a fast operating speed.

[0041] [Air pressure control (operating speed)]

[0042] If the speed at which the space 4 expands is different, it is necessary to change the amount of air 5 blown out from the air outlet 22 of the punch 2. That is, when the speed at which the space 4 expands becomes faster, it is necessary to increase the amount of air 5 supplied per unit time.

[0043] The increase in the supply amount of the air 5 per unit time is performed by increasing the pressure of the supply air 5 .

[0044] Based on the above, when the operating speed of the can body manufacturing machine is increased, the pressure of the supplied air 5 is increased.

[0045] Therefore, the relationship between the operating speed of the can body manufacturing machine and the air pressure is specified in advance, and each time a can is formed (each impact), the air pressure (operating speed) is controlled by the control device in such a way that the air pressure corresponds to the operating speed at the time of the impact.

[0046] For example, to become Figure 2 The operation speed at the start of the operation is 100 spm (shot / minute) and the air pressure at this time is 100 kPa. Thereafter, the operation speed is gradually increased to 140 kPa at 200 spm, 170 kPa at 300 spm, and 180 kPa at 400 spm, and the tank 1 is punched.

[0047] The pressure of the air can be controlled using, for example, a well-known electropneumatic regulator or the like.

[0048] It should be noted that the operating speed and air pressure and their combination may be appropriately set to optimal values ​​in consideration of the type and components of the press machine, the type and size of the can to be manufactured, the manufacturing process, etc., and are not limited to the above. Figure 2 In addition, the relationship between the operating speed and the air pressure is not limited to Figure 2 The broken line shown in the chart can also be a straight line, a curve or a combination thereof.

[0049] [Air blowing timing control (operating speed)]

[0050] The air 5 is not supplied all the time, but is supplied when the punch 2 is pulled out from the tank 1. Therefore, an opening and closing valve (not shown), such as a solenoid valve, is provided in the supply path of the air 5 to the air blowing outlet 22 of the punch 2. The opening and closing valve is used to control the operating timing of the opening and closing valve (the timing of blowing out the air) in such a way that the air 5 is supplied from the air blowing outlet 22 in accordance with the timing when the punch 2 is pulled out from the tank 1.

[0051] The opening and closing valve is provided outside the punch 2, and there is a predetermined distance between the opening and closing valve and the air outlet 22. Although the air blown out in the previous impact will remain between the opening and closing valve and the air outlet 22, there will be a time delay from the operation time of the opening and closing valve (air blowing time) before the air 5 is actually blown out from the air outlet 22 and the air 5 is fully supplied to the space 4 between the tank bottom 11 and the punch front end 21. It should be noted that the operation of the opening and closing valve itself also has a slight time delay.

[0052] As described above, the operating speed of the can body manufacturing machine varies, and the influence of the time delay from the operation timing of the on-off valve (the blowing timing of air) varies depending on the operating speed of the can body manufacturing machine.

[0053] Even if the operating speed of the can body manufacturing machine changes, the time delay of the air supply does not change. Therefore, if the operating speed increases, it is necessary to advance the operation timing of the on-off valve (air blowing timing).

[0054] Therefore, the relationship between the operating speed of the can body manufacturing machine and the operating timing of the opening and closing valve (air blowing timing) is determined in advance, and the operating timing of the opening and closing valve (air blowing timing) is controlled by the control device in a manner that corresponds to the operating speed.

[0055] In addition, the time delay from the operation time of the on-off valve (the time of blowing air) itself changes according to the pressure of the blown air. If the air pressure is high, the time delay tends to decrease, and if the air pressure is low, the time delay tends to increase.

[0056] Therefore, the relationship between the air pressure and the operating timing of the opening and closing valve (the timing of blowing out the air) is specified in advance, and each time the can is molded (each impact), the control device controls the operating timing of the opening and closing valve (the timing of blowing out the air) to correspond to the air pressure during the impact.

[0057] As described above, the operation timing of the on-off valve (air blowing timing) at each impact is controlled according to the operating speed of the can body manufacturing machine at the time of the impact or the pressure of the blown air.

[0058] Furthermore, if the operation timing of the on-off valve (air blowing timing) is controlled according to the operating speed of the can body manufacturing machine and the pressure of the blown air at each impact, it can be controlled to a more appropriate timing.

[0059] [Control example of air blowing timing control (operation speed)]

[0060] In the control of the operation timing of the opening and closing valve (the blowing timing of the air), for example, a well-known electronic cam switch with an automatic advance angle function is used. The electronic cam switch is provided with a detector for detecting the rotation angle (0° to 360°) on the rotating shaft, and outputs a switch signal in response to the output of an angle signal corresponding to a specified angle (°) from the detector. The automatic advance angle function can set an advance angle correction angle (°) corresponding to the rotation speed of the rotating shaft, and outputs a switch signal in response to the output of the angle signal, and the angle signal corresponds to an angle that is advanced from the specified angle (°) by the set advance angle correction angle (°) according to the rotation speed.

[0061] The opening and closing control of the on-off valve is performed based on the switch signal output from the electronic cam switch. The detector is attached to the rotating shaft that drives the punch 2. The rotating shaft performs one impact in one rotation.

[0062] For example, at the reference operating speed (0spm) and air pressure (170kPa), the angle of the rotating shaft (operating time of the opening and closing valve (air blowing time)) for controlling the opening and closing valve to open is 180°. At this time, if the operating speed (rotation speed of the rotating shaft) becomes faster, the influence of the time delay becomes larger, but the operating time of the opening and closing valve (air blowing time) based on this influence, that is, the delay conversion angle (°) as the adjustment amount of the rotating shaft is determined in accordance with the rotation speed. In the automatic advance angle function of the electronic cam switch, these rotation speeds and delay conversion angles are set as the speed of the rotating shaft and the advance angle correction angle.

[0063] The setting of the speed of the rotating shaft and the advance angle correction angle in the automatic advance angle function is also performed at another air pressure, for example, 140 kPa.

[0064] Figure 3 (a) of FIG. 1 shows a table of these operating speeds (rotation speeds of the rotating shaft) and delay conversion angles (advance angle correction angles). It should be noted that: Figure 3 The "corrected ON angle (°)" in (a) is a value obtained by subtracting the delay conversion angle (advance angle correction angle) from the reference angle 180° for controlling the opening of the on-off valve. Figure 3 The graph obtained by graphing the table (a) is Figure 3 (b).

[0065] like Figure 3 (a) and Figure 3 As shown in (b), it can be seen that if the operating speed becomes faster, the delay conversion angle becomes larger and the corrected ON angle becomes smaller. Therefore, the angle of the rotating axis for controlling the opening of the on-off valve (the working timing of the on-off valve (the blowing timing of the air)) is smaller than the reference angle of 180°, that is, the timing is advanced.

[0066] Furthermore, it can be seen that as the air pressure decreases, the delay conversion angle increases.

[0067] In this way, the operation timing of the on-off valve (the blowing timing of air) is controlled according to the operating speed of the can body manufacturing machine and the pressure of the blown air.

[0068] It should be noted that the operating speed, air pressure, delay conversion angle, and their combination can be appropriately set to optimal values ​​in consideration of the type and components of the press machine, the type and size of the can to be manufactured, the manufacturing process, etc., and are not limited to the above. Figure 3In addition, the operating speed, air pressure and delay conversion angle and their combination are not limited to the following. Figure 3 The broken line shown in the chart can also be a straight line, a curve or a combination thereof.

[0069] [Compound control (operation speed)]

[0070] As described above, the air pressure or the air blowing timing is controlled to the optimal value for each impact according to the operating speed of the press machine, but a composite control (operating speed) of controlling the air pressure and the air blowing timing to the optimal values ​​may be performed.

[0071] In the compound control (operating speed), the air pressure control (operating speed) and the air blowing timing control (operating speed) are not simply controlled separately by the set values, but it is preferred to set the air pressure and the air blowing timing by considering the synergistic effect of the air pressure control and the air blowing control.

[0072] [Air blow-out control (first tank)]

[0073] The can body manufacturing machine starts to operate, and during the impact of molding the first can (the first can) after the operation starts, there is no air with a sufficiently high pressure in the air supply path 23 reaching the air blowing outlet 22, so sufficient air is not supplied to the space 4 between the bottom 11 of the can and the front end 21 of the punch.

[0074] Thus, in the impact of molding the first tank, even if the molding is performed under the same conditions as the impact of molding other tanks, such as the second tank, the same impact will occur. Figure 4 The problem shown in (a).

[0075] [Air pressure control (first tank)]

[0076] During the impact of the molding process on the first tank, air pressure control is performed (first tank). The air pressure control supplies air with a higher pressure than the air pressure during the impact molding of the second tank when other processing conditions such as the operating speed are the same, thereby supplying sufficient air to space 4.

[0077] For example, if the operating speed at the start of operation is set to 100spm, Figure 2 As shown, the air pressure at this time is set to 100 kPa, and in the impact of molding the first tank, the air pressure is set to a high pressure of 140 kPa.

[0078] It should be noted that the pressure of the air during the impact for forming the first tank can be appropriately set to the optimal value by considering the type and components of the stamping machine, the type and dimensions of the tank to be manufactured, the manufacturing process, and the pressure of the air when it is not the first tank.

[0079] [Air blowing time control (first tank)]

[0080] During the impact of the molding process on the first tank, air blowing timing control is performed (first tank), and the air blowing timing control supplies air at an earlier air blowing timing than the air blowing timing during the impact molding of the second tank with the same other processing conditions such as the operating speed, thereby supplying sufficient air to the space 4.

[0081] For example, if the air pressure at the start of operation is set to 100 kPa and the operating speed is set to 100 spm, the delay conversion angle is 14°. In the impact of molding the first tank, the air blowing timing is set to an early delay conversion angle of 16°.

[0082] It should be noted that the timing of blowing air during the impact of molding the first tank can be appropriately set to the optimal value by considering the type and components of the punching machine, the type and sizes of the tanks to be manufactured, the manufacturing process, and the timing of blowing air when it is not the first tank.

[0083] [Compound control (first tank)]

[0084] As described above, the air pressure or the air blowing timing is controlled to the optimal value each time the first tank is impacted for molding, but a composite control (first tank) in which the air pressure and the air blowing timing are controlled to the optimal values ​​may be performed.

[0085] In the compound control (first tank), the air pressure control (first tank) and the air blowing timing control (first tank) are not simply controlled separately by the set values, but it is preferred to set the air pressure and the air blowing timing by considering the synergistic effect of the air pressure control and the air blowing control.

[0086] Although the embodiments of the present invention have been described in detail with reference to the drawings, the specific configuration is not limited to these embodiments, and design changes and the like within the scope not departing from the gist of the present invention are also included in the present invention.

[0087] Furthermore, the above-mentioned embodiments may be combined by using the mutual techniques as long as there are no particular contradictions or problems in their purposes, structures, etc.

[0088] Description of Reference Numerals

[0089] 1: can;

[0090] 11: Tank bottom;

[0091] 2: Punch;

[0092] 21: front end of the punch;

[0093] 22: air outlet;

[0094] 23: air supply path;

[0095] 3: demoulding device;

[0096] 4: Space;

[0097] 5: Air.

Claims

1. A method for manufacturing a can, using a drawing process and / or a drawing ironing process using a punching machine, wherein the method for manufacturing a can is characterized in that: A demoulding step is provided for extracting the punch from the tank after the drawing process and / or the drawing ironing process. In the demolding step, air assist is performed by blowing air from an air blowing port at the front end of the punch to assist the extraction of the punch. In the air assist, the pressure of the air and / or the blowing time of the air are adjusted to the pressure and / or the blowing time corresponding to the condition of the impact every time the impact occurs.

2. The method for manufacturing a tank according to claim 1, characterized in that: The pressure of the air is adjusted to a pressure corresponding to the operating speed during the impact.

3. The method for manufacturing a tank according to claim 1, characterized in that: In the case where the shock is the first shock to the tank after the start of operation, the pressure of the air is adjusted to be higher than the pressure during the shock with other conditions being the same, and / or the blowing time of the air is adjusted to be earlier than the blowing time during the shock with other conditions being the same.

4. The method for manufacturing a tank according to claim 1, characterized in that: The timing of blowing out the air is adjusted to a timing corresponding to the operating speed during the impact and / or the pressure of the air.

5. The method for manufacturing a can according to any one of claims 1 to 4, characterized in that: The punching machine is a can body making machine.

6. A can manufacturing device, using deep drawing and / or deep ironing, wherein the can manufacturing device is characterized in that: Equipped with: punch, demoulder and control device, The punch has an air outlet at the front end for blowing out air. The control device performs air blowing control to blow air from the air blowing port when the demolding device is engaged with the end of the can and the punch is pulled out from the can. In the air blowing control, the pressure of the air and / or the blowing time of the air are adjusted to the pressure and / or the blowing time corresponding to the condition of the impact every time the impact occurs.

7. The can manufacturing device according to claim 6, characterized in that: The control device adjusts the pressure of the air to a pressure corresponding to the operating speed during the impact.

8. The can manufacturing device according to claim 6, characterized in that: When the impact is the first impact on the tank after the start of operation, the control device adjusts the pressure of the air to be higher than the pressure during the impact with other conditions being the same, and / or adjusts the blowing time of the air to be earlier than the blowing time during the impact with other conditions being the same.

9. The can manufacturing device according to claim 6, characterized in that: The control device adjusts the blowing timing of the air to a timing corresponding to the operation speed during the impact and / or the pressure of the air.

10. The can manufacturing device according to any one of claims 6 to 9, characterized in that: The manufacturing device is a can body making machine.

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