JPS6011576B2 - Manufacturing equipment for flanged drawn bodies - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an apparatus for manufacturing a flanged drawn body made of a flexible material. The present invention relates to an apparatus for manufacturing a flanged drawn body made of a flexible material that prevents the body from collapsing.

Here, the flexible material refers to a metal foil, metal sheet, plastic film, plastic sheet, or a laminate thereof, which has poor rigidity and is flexible.

There are no particular restrictions on the thickness, but it is usually about 7 to 200 mm.
The closing film or sheet falls under this category. When drawing these flexible materials in the usual way,
The occurrence of wrinkles at the shoulder curvature of the die is severe, and these wrinkles cover almost the entire surface of the body wall of the molded product, which not only impairs the aesthetic appearance, but also makes it difficult to connect the flange and lid when using the product as a container. There is a risk that the sealing will be incomplete, leading to leakage of the contents or deterioration of the contents due to inflow of air or moisture. In order to solve this problem, the present inventors first provided a rigid core and a cylindrical part made of an elastic material surrounding the core, and the outer diameter of the cylindrical part was equal to the shoulder curvature of the die. We have proposed a method and apparatus for drawing and forming flexible materials using a punch larger than the minimum diameter (Tokugan Sho 52-79532 and Sho 53-96676). In this drawing method, the cylindrical part of the punch, which is an elastic body, enters the die cavity while being compressed in the radial direction, so that at the end of the forming process, the body wall of the molded body forms between the outer surface of the punch and the inner surface of the die cavity. It is under radial pressure between.

Therefore, in the punch extraction process, when the punch and the molded body are extracted together from the die cavity, the die cavity
The body wall portion coming out of the cavity is expanded outward due to the punch cylindrical body attempting to return to its original shape by expanding in the radial direction, causing the shape of the molded body to collapse. However, conventional backward-moving presses are designed so that the blank holder starts to rise almost simultaneously with the rise of the punch, as described below, so it is inevitable that the punch and the compact will come out together, and therefore the forming The shape of the body was distorted, making it difficult to obtain a satisfactory product. Furthermore, even if measures are taken to prevent the punch and the molded body from being pulled out together, the following problems occur due to the nature of flexible materials.

In other words, in this case, the molded body remains in the die cavity and only the punch is extracted, but if the punch rises rapidly, even if there is a ventilation hole penetrating the inside of the punch, the molded body will remain in the die cavity and the punch will be pulled out. The space formed by the inner surface of the molded body is in a reduced pressure state, and even if the degree of pressure reduction is small, the shape of the molded body will collapse because a maneuverable material is used. The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to have no wrinkles and no deformation, that is, at the end of drawing (when the punch reaches the bottom dead center). An object of the present invention is to provide a pumping press for drawing a flanged draw-formed body made of a flexible material that retains its original shape.

The present invention includes a first ram for raising and lowering the punch and a second ram for raising and lowering the plank holder, the first ram being driven via a crank, and the second ram being fixed to the shaft of the crank. In a double-acting press for drawing, which is driven via a cam, the press has a rigid core and a cylindrical part made of an elastic material surrounding the core, and the outer diameter of the cylindrical part is is larger than the minimum diameter of the shoulder curvature of the cooperating dies, and the profile of the cam is such that at least the tip of the punch at the tip of the first ram extends from its bottom dead center to the tip of the second ram. A flexible material, characterized in that the tip of the blank holder is formed so that it remains at the bottom dead center during the period until the tip of the blank holder reaches almost the bottom dead center. The present invention provides a double-acting press for drawing a flanged molded body.

Furthermore, the present invention includes a first ram for raising and lowering the punch and a second ram for raising and lowering the blank holder, the first ram being driven via a crank, and the second ram being fixed to the ratchet of the crank. In a double-acting draw-forming press driven by a cam, the pump has a rigid core and a cylindrical part made of an elastic material surrounding the core, and the outer diameter of the cylindrical part is is larger than the minimum diameter of the shoulder curvature of the cooperating dies, and a through hole with an opening □ on the tip surface passes through the core, and the through hole communicates with the pressurized fluid supply passage. The profile of the cam is such that at least the tip of the punch at the tip of the first ram moves from its bottom dead center to approximately the bottom dead center of the tip of the blank holder at the tip of the second ram. The tip of the blank holder is formed so as to remain at its bottom dead center during the period until reaching the above period, and means for detecting the rotation angle of the crankshaft corresponding to the period, and based on the detection signal. and a means for opening the pressurized fluid supply passage, and the pressurized fluid is injected from the tip end face of the punch during at least the above-mentioned period. The present invention provides a double-acting press for molding.

The present invention will be explained in detail below.

Drawing machines can be roughly divided into single-acting type and penetrating type, but a sliding-acting type forming machine is more suitable for drawing a malleable material for the following reasons. A conventional single-acting drawing machine uses a fixed punch, a die that is attached to a ram to reciprocate, and a stub from which the die descends, and a fixed duct (pressure device) that applies pressing force via a pressure pin. Although the overall structure is relatively simple, it has the following problems.

In other words, due to its mechanism, the wrinkle holding plate must move at least a distance corresponding to the drawing depth, and large changes in the wrinkle holding force during this period are unfavorable for drawing Z forming, so the capacity of the duction is increased. In addition, the duct must be adjusted using a valve or the like, making the duct larger or more complicated. Furthermore, in addition to the forming force, a wrinkle suppressing force acts on the die that is attached to the ram, and since drawing forming must be performed against the Z resultant force of both, the ram and its drive mechanism (crankshaft, clutch brake etc.), it is inevitable that the size will be larger than when drawing is performed only against the forming force. This point is less of a problem when drawing a thin metal plate 2 of normal thickness (for example, a tin plate with a skin thickness of 0.3 mm) because the required wrinkle pressing force is small compared to the forming force. However, in cases where the required wrinkle pressing force is much larger than the forming force (for example, forming force:
Wrinkle holding force = 1:3) requires a ram with several times the capacity and its auxiliary mechanism than that required for the actual forming force, and also consumes extra energy that does not contribute to the forming force itself. As a result, it is inevitable that it will be economically disadvantageous. FIG. 1 shows an embodiment of the double-acting press of the present invention.

As shown in FIG. 2, the punch 1 is composed of a rigid core la made of steel and a cylindrical part lb made of an elastic material such as polyurethane rubber surrounding the lower part of the core la. A through hole lc, which fits a pressurized fluid supply passage 29 to be described later, passes through it.

The outer diameter of the cylindrical part lb is larger than the minimum diameter of the shoulder curvature part 16c of the die 16, that is, the inner ridge of the upper end of the die cavity direct weaving part 16a, and is preferably larger than the maximum diameter of the shoulder curvature part 16c of the die, that is, the inner ridge of the upper end of the die cavity direct weaving part 16a. It is determined to be approximately equal to the minimum inner diameter of the wrinkle holding plane.With this configuration, elastic pressure is applied at the shoulder curvature of the die during drawing, so even flexible materials that are prone to wrinkles can be squeezed. The punch 1 is fixed at the lower center of the punch elevating ram 2, and both ends of the punch elevating ram 2 are connected to a punch elevating shaft 3 and a yoke 4. , is connected to the crank pin 6 via the connecting lever 5.

The crankshaft 7 is rotated by a drive mechanism (consisting of a motor, flywheel, clutch, etc.) located on the left side of FIG. 1, so that the punch lifting shaft 3 slides on the inner surface of the blank holder lifting shaft 8. and move it up and down. The blank holder 9 is pressed by a cushion pin 12 against the inner surface 11a of a blade portion of a cutter 11 (for cutting blanks) fixedly provided at the lower part of a ram 10 for lifting and lowering the blank holder.

The cushion pin 12 is connected to a piston 15 that moves up and down in a cylinder 14 that is connected to a compressed air tank (not shown) and a through hole 13, so that when the blank holder lifting ram 10 reaches the bottom dead center, The blank holder is configured to be able to press the drawing material 23 (FIG. 5-a) on the die 16 with a predetermined pressure. Both ends of the blank holder elevating ram 101 are fixed to the blank holder elevating shaft 8, and the lower end of the blank holder elevating shaft 8 is connected to the crankshaft 7 via a yoke 17, a cam follower 18, and a cam 19.
Due to the rotation of the crankshaft 7, the blank holder lifting shaft 8 is moved to the bed 2 by the action of the cam 19 and the return spring 21.
The plank holder 9 is configured to slide up and down by sliding on the inner surface of a bush 22 provided between the plank holder 9 and the plank holder 9. FIG. 3 shows an embodiment of the profile of the cam 19 of the present invention. The figure shows the state when the punch elevating ram 2 is exactly located at the top dead center. When the cam 19 rotates in the direction of the arrow from this point as a starting point, the blank holder 9 is at its top dead center until point b reaches point a along the arc a-b. Located in In addition, in FIG. 4, the relationship between the vertical position of the blank holder 9 and the punch 1 and the rotation angle of the crankshaft 7 is shown, respectively.

Next, as point c approaches point a, the blank holder 9 descends, and when it coincides with point a, it reaches the bottom dead center (point c in FIG. 4). Here the length of oc is greater than the length of ob (
Point o is the center point of the cross section of the crankshaft 7). cde is a circular arc, and the blank holder 9 remains at the bottom dead center until points d and e coincide with point a. During this time, when the point d coincides with the point a, the punch elevating ram, that is, the punch 1 reaches the bottom dead center 1, and the drawing process ends. Thereafter, the punch 1 rises, that is, the process of extracting the punch from the molded object begins, but at least the period until the tip ld of the punch reaches almost the bottom dead center of the blank holder tip 9a, that is, the punch tip surface It is important that the blank holder 9 stays at its bottom dead center while ld is rising within the cavity 16a of the die 16. That is, it is important that point e in FIG. 4 is located almost immediately before or after curve 0 (in terms of angle). The reason for this is explained in Section 5a, which is an enlarged cross-sectional view of the punch 1 and die 16 and shows the drawing behavior.
This will be explained with reference to Figures 5e to 5e.

Fig. 5-a shows the case where both the punch 1 and the plank holder 9 are at the top dead center, that is, the angle is 0 degrees (point a) in Fig. 4, and the maneuverable material that is the material to be formed 23 is It is placed on the wrinkle pressing surface 16b of the die 16.

FIG. 51b shows the point in time when the blank holder 9 starts pressing the blank after the blank holder elevating ram 10 has descended and the cutter 11 has cut the material 23 to be formed outside the plan, that is, in FIG. Angle 110 degrees (point c)
Indicates the status of FIG. 51c shows a state when the punch 1 reaches the dead center, that is, at an angle of 180 degrees (point d) in FIG. Since the playable material is pressed during the drawing process, the formation of wrinkles in the molded product is prevented. The elastic material that has entered the die cavity 16a is compressed in the radial direction and presses the molded body arm wall toward the inner surface of the die. Fifth
Figure 1d shows the punch extraction process, that is, angle 1 in Figure 4.
A state between 80 and 240 degrees (points d to e') is shown.
During this period, it is important that the blank holder 9 is located at the bottom dead center and presses the flange 24a of the molded body 24 to prevent the molded body 24 from slipping out of the die cavity 16a together with the punch 1. As shown in FIG. 6-a, the part 24b of the arm wall of the molded body that has come out is expanded in the radial direction because the elastic material expands in the radial direction and restores its shape. This is because the shape is unreliable, and it becomes worthless as a product. The lower end surface ld of the punch 1 is
In order to adjust the shape of the bottom surface of the molded body, it is desirable that the punch be made of a rigid body, and therefore, a rigid body portion le having a certain thickness h protrudes from the lower part of the punch 1. Therefore, the upper end of the lower rigid portion le is the wrinkle pressing surface 16b of the die 16.
When the blank holder 9 reaches the level of , that is, when the thickness h remains in the die cavity 16a, that is, at an angle of 230 degrees (point e) in the example of FIG. No such defects occur. The reason why point e is located slightly before point e' in FIG. 4 is based on the above reason. Fig. 5-e shows a state in which both the punch 1 and the blank holder 9 have reached the top dead center, that is, the state has returned to the 360 degree angle (point a) in Fig. 4, and the molded body 24 having a normal shape is shown. It is ejected from the die cavity 16a by the knockout 32. Therefore, in the present invention, it is important to set the central angle 8 of the arc portion de of the cam 19.

Now, if the stroke of the punch is x (the distance between the top dead center and the bottom dead center) and the distance between the bottom dead center of the punch and the bottom dead center of the blank holder is y, then from a geometric calculation, the center angle h is The conditions of the present invention are satisfied when S-containing three is approximately equal to or larger than this value. On the other hand, the cam profile of a conventional cam-type double-action press can be found, for example, on page 323 of "Press Handbook (edited by the Plastic Working Research Group, published by Maruzen, 1956)" and on page 21 of Special Publication No. 50-117032. As shown in Figures 7 and 8, the angle 8 is much smaller, point e is closer to point d, and the lower end of the punch still remains in the die cavity. While there, the blank holder begins to rise. Therefore, when using a conventional double-acting press, even if the punch is modified as in the present invention, the shape will collapse as shown in Figure 6-a. It is impossible to obtain a body. Next, in the double-acting press of the present invention, a cam 25 is provided at one end of the crankshaft 7, and the blot of the cam 25 is formed to turn on a limit switch 26 at least during the punch extraction process. There is.

A signal from limit switch 26 is transmitted to electromagnetic valve 28 through conductor 27 . The solenoid valve 28 is provided in the pressurized fluid supply passage 29 together with a pressure regulating valve 30 and a filter 31 . Pressurized fluid such as compressed air whose pressure is adjusted by the pressure regulating valve 30 is injected into the space formed by the inner surface of the molded body through the punch tip surface through the through hole lc of the punch 1 only when the limit switch 26 is ON. (Figure 5-d).
The reason for this configuration is that when the punch extraction speed is high due to high-speed molding, even if the punch 1 is provided with a through hole that can communicate with the outside air, the space will rapidly increase in volume and become depressurized. This is because the molded body made of flexible material may not be able to resist the reduced pressure and its shape may collapse. If no through holes are provided,
As shown in Figures 6-a and 6-b, even when the punch is pulled out at a low speed, the punch is pulled out with the lower end of the punch and the bottom of the molded product in close contact, so the shape of the molded product is completely collapsed. I end up. The pressure of the pressurized fluid must be within an appropriate range determined by the type of fluid and flexible material, the size and shape of the molded object, the punch hole diameter, length, press speed, etc. That is, if the pressure is too low, the above effects cannot be achieved, and if the pressure is too high, the bottom of the molded body may be deformed or damaged. To give an example, if the malleable material is 1
In the case where the sand is a laminated film made of polyethylene terephthalate, aluminum foil, and polypropylene with a thickness of 70 mm, the molded body has a diameter of 70 mm, a depth of 3 ribs, a through hole diameter of 6 ribs, and a press speed of 70 times per minute. , the supply air gauge pressure is preferably approximately 0.5k9/m.

In this case, at 0.4k9/m, the bottom of the molded body dents inward, and at 0.6k9/m, it expands outward. As described above, according to the apparatus of the present invention, when drawing and forming a flexible material, a punch surrounded by an elastic material is used in the drawing process, thereby preventing the formation of wrinkles in the formed product. In the punch extraction process, by timing the rise of the punch and blank holder appropriately, it is possible to prevent the shape of the body of the molded product from collapsing due to the gunwale, and to By injecting the pressurized fluid, there is an advantage that deformation of the bottom of the molded body can be prevented. In the above embodiments, the shape of the molded product is cylindrical, but the present invention is not limited to this. For example, the present invention provides a method and apparatus for producing molded products such as elliptical cylinders and square cylinders with rounded corners. Needless to say, it is included in

[Brief explanation of the drawing]

FIG. 1 is a partially sectional front view of the device of the present invention, and FIG.
A cross-sectional view of the punch shown in FIG. 1 taken along the line 010, and FIG. 3 a cross-sectional view taken along the line mm of FIG. Figure 4 shows relationship curve diagrams between the crankshaft rotation angle and the vertical positions of the blank holder and punch in the present invention. Figure 5-e shows the drawing process diagram of the present invention, Figures 6-a and 6-1b show the behavior of the molded body in the punch drawing process when the conventional device is used, and Figure 7
The figure shows a cam profile of a conventional device, and FIG. 8 shows a relationship curve between the crankshaft rotation angle and the vertical position of the blank holder and punch in the conventional device. 1... Punch, la... Rigid core, lb
...Cylindrical part, lc...Through hole, 2...
- Ram for lifting and lowering punch, 7... Crank shaft, 9... Blank holder, 10... Ram for lifting and lowering blank holder, 16... Die, 16c... Die shoulder curvature, 19... ...Cam, 23... Maneuverable material, 2
4...Drawn body, 24a...Flange, 25...
Cam (means for detecting the rotation angle of the crankshaft), 26...
... Limit switch (means for detecting the rotation angle of the crankshaft), 28 ... Solenoid valve (means for opening the pressurized fluid supply passage), 29 ... Pressurized fluid supply aisle. Figure T Figure 2 Figure 3 Figure M Figure 5-a Figure 5-b Figure 5-c Figure 5-d Figure 5-6 Figure 6-a Figure 6-b Figure 7 Figure 8

Claims (1)

[Claims] 1. A first ram for raising and lowering a punch and a second ram for raising and lowering a blank holder, the first ram being driven via a crank, and the second ram being driven by the shaft of the crank. In a double-acting press for drawing, which is driven via a cam fixed to the punch, the punch has a rigid core and a cylindrical part made of an elastic material surrounding the core; The outer diameter is greater than the minimum diameter of the shoulder curvature of the cooperating die, and the profile of the cam is such that at least the tip of the punch at the tip of the first ram is positioned from its bottom dead center to the second ram. A flexible material characterized in that the tip of the blank holder is formed such that the tip of the blank holder remains at the bottom dead center until the tip of the blank holder reaches substantially the bottom dead center. A double-acting press for drawing formed bodies with flanges. 2 Equipped with a first ram for raising and lowering the punch and a second ram for raising and lowering the blank holder, the first ram is driven via a crank, and the second ram is driven via a cam fixed to the shaft of the crank. In a double-acting press for drawing, which is driven by
The punch has a rigid core and a cylindrical part made of an elastic material surrounding the core, and the outer diameter of the cylindrical part is larger than the minimum diameter of the shoulder curvature of the cooperating die. A through hole having an opening at its distal end surface passes through the core, and the through hole communicates with the pressurized fluid supply passage, and the profile of the cam is located at least at the distal end of the first ram. During the period from when the tip of the punch reaches almost the bottom dead center of the tip of the blank holder at the tip of the second ram, the tip of the blank holder reaches almost the bottom dead center of the tip of the blank holder located at the tip of the second ram. and means for detecting the rotation angle of the crankshaft corresponding to the period, and means for opening the pressurized fluid supply passage based on the detection signal,
A double-acting press for drawing a flanged molded body made of a flexible material, characterized in that pressurized fluid is injected from the tip end face of the punch at least during the above-mentioned period.