JP2016078101A - Method and device for manufacturing molded body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device and a method for easily and simply manufacturing a seamless cylindrical body having a length 10 times larger than its diameter.SOLUTION: The manufacturing method implemented by using a manufacturing method including a die 10 having a gap 17, a punch 20, and a blank holder 40 installed above the die 10 includes a step A of installing a blank between the die and the blank holder and executing deep drawing by the punch to form a concave body, a step B of lifting an upper punch in the concave body to form a gap from the concave body, a step C of applying a load between the concave body and the die and removing the gap to set the shape of the concave body along the shape of the punch, and a step D of simultaneously lowering the punches, and repeats the steps B and C by a predetermined number of times.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a manufacturing method and a manufacturing apparatus for manufacturing a molded body such as a cylindrical molded body, and more particularly to a manufacturing method and a manufacturing apparatus capable of manufacturing a microscale cylindrical molded body as a seamless molded body. .

In the development of micro devices and injection needles, the demand for micro-scale cylindrical molded bodies is increasing.
As a method of manufacturing a microscale fine cylindrical part, a method of drawing a tube or a method of deep drawing from a plate-like material is used, but any method can manufacture a microscale part. Was difficult.
According to the method of pulling out the pipe, it is difficult to manufacture the mold, handle and handle it, and it is difficult to manufacture the mold. For this reason, dieless processing without using a metal mold has been studied, but there is a problem that microfabrication is difficult because material deterioration due to heating and surface damage are likely to occur. Further, in the deep drawing using a metal foil, the microneedle could not be manufactured because the deep drawing was difficult even in the multi-step due to the problem of lubrication and the limit of the load bearing capacity of the fine tool.
In general, various ultra-deep drawing techniques that significantly improve the deep drawing limit have been proposed. However, the previously proposed techniques have not solved the above-mentioned problem of deep drawing, and the fine deep drawing on the micro scale has not been solved. In particular, it has been impossible to perform ultra-deep drawing that makes the depth 3 times, 4 times, 5 times or more of the diameter of the cylinder (when the cylindrical body is cylindrical).
For this reason, various methods for manufacturing a microscale cylindrical body have been proposed, and techniques (such as Patent Documents 1 to 6) for rounding a plate into a cylindrical shape have been proposed.

JP2003-136142 JP2003-190282 JP2003-200218 JP2003-320430 JP2004-136343 JP2007-038021

However, in the techniques of Patent Documents 1 to 6, since the plate is rounded into a cylindrical shape, a seam is formed in the length direction of the cylinder, and thus there is a problem that it is not suitable as a component of a microdevice. In short, a technique for producing a seamless cylindrical body having a length of 10 times or more of the diameter of the cylindrical body has not been proposed yet, and there is a demand for development of such a technique.
Accordingly, an object of the present invention is to provide a technical manufacturing apparatus and a manufacturing method for easily and simply manufacturing a seamless cylindrical body that is a cylindrical body and has a length of 10 times or more the diameter thereof. is there.

As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that it is important to mold the base plate while allowing it to flow into the punch, and to complete the present invention based on such knowledge. It came.
That is, the present invention provides the following inventions.
1. In a method for producing a molded body having a predetermined shape using a deep drawing molding apparatus comprising a die, a punch, and a blank holder,
The die has a void, the void is columnar, has a large diameter portion with a large diameter, and a small diameter portion with a small diameter connected to the large diameter portion,
The punch includes a columnar internal punch and a cylindrical external punch arranged around the inner punch, and the external punch is smaller than the diameter of the large diameter portion and larger than the diameter of the small diameter portion. Has a diameter,
A step of placing a base plate between a die and a branch holder and performing a deep drawing with the punch to form a concave body,
A step B of lifting the external punch upward inside the concave body to form a gap between the concave body and the punch,
Step C, in which an internal pressure is applied between the concave body and the die to eliminate the gap, and the shape of the concave body conforms to the shape of the punch,
A manufacturing method characterized by performing step D in which the external punch and the internal punch are simultaneously lowered downward, and further repeating step B and step C a predetermined number of times.
2. A manufacturing apparatus for performing the manufacturing method according to 1, comprising a die having a gap, a punch, and a blank holder installed above the die,
The voids in the die are columnar and have a large diameter portion with a large diameter and a small diameter portion with a small diameter connected to the large diameter portion,
The punch includes a columnar internal punch and a cylindrical external punch arranged around the inner punch, and the external punch is smaller than the diameter of the large diameter portion and larger than the diameter of the small diameter portion. A manufacturing apparatus having a diameter and having a gap between the punch and the die.
3. The die has a step portion that forms the large diameter portion and the small diameter portion,
3. The manufacturing apparatus according to 2, wherein the step portion includes a chamfered shoulder portion, a flat portion, and a fillet portion.

The manufacturing method of the molded object of this invention can manufacture said seamless cylindrical body easily and simply.
The manufacturing apparatus for a molded body of the present invention is a cylindrical body that can manufacture a seamless cylindrical body having a length of 10 times or more of its diameter.

FIG. 1 is a cross-sectional view showing a cross-sectional structure (showing a cross section along the central axis) of the main part of the manufacturing apparatus of the present invention. FIG. 2 is a schematic diagram showing a state immediately before operating the apparatus shown in FIG. FIG. 3 is a schematic diagram for explaining the operation of the apparatus shown in FIG. 1, and (a) to (d) are schematic diagrams showing the operation in the order of time series. FIG. 4 is a schematic diagram showing a state where Steps B to D are further repeated from the state shown in FIG. FIG. 5 is a perspective view showing a longitudinal section of a hollow rod-shaped molded body produced using the production apparatus and production method of the present invention.

Hereinafter, the present invention will be specifically described with reference to the drawings, but the present invention is not limited thereto.

<Overall configuration>
First, the manufacturing apparatus used for the manufacturing apparatus of this invention is demonstrated.
As shown in FIG. 1, the apparatus 1 of this embodiment includes a die 10 having a gap 17, a punch 20, and a blank holder 40 installed above the die 10.
Details will be described below.

<Die>
As shown in FIGS. 1 and 2, the gap 17 is columnar and has a large-diameter portion 16 having a large diameter and a small-diameter portion 18 having a small diameter connected to the large-diameter portion 16. The die 10 has a cylindrical shape, and is provided at an upper portion, an upper cylindrical portion 12 that forms a large-diameter portion 16, a lower cylindrical portion 14 that is provided at a lower portion and forms a small-diameter portion 18, and the upper cylindrical portion 12 and the lower portion. It consists of a doughnut-shaped step portion 15 provided between the cylindrical portion 14. In the present embodiment, the die 10 is an integral type, but it may be formed by forming the upper cylindrical portion and the lower cylindrical portion as separate members and connecting them together.
As shown in FIG. 2, the step portion 15 includes a shoulder portion 15a, a flat portion 15b, and a fillet portion 15c, and the shoulder portion 15a and fillet portion 15c are curved surfaces having a predetermined radius of curvature. Thereby, when the punch 20 is lowered and the concave body comes into contact with the step portion 15, the concave body easily flows toward the internal punch 22. The structure that exerts such an action is not limited to the above-described shape. For example, a shape that promotes the flow of the base plate, for example, a flat portion is a tapered portion provided at a predetermined angle with respect to the axial direction of the die. If it is, it is possible to employ without any particular limitation. In the present specification, “upward” means the supply side of the base plate, and “downward” means the discharge direction of the molded body after the molding process.
Further, a cylindrical blank holder 40 is provided above the die 10, and a flow path 50 through which a pressure medium for pressurizing an internal pressure described later flows between the blank holder 40 and the die 10. Is formed. The flow path 50 has a donut shape in the present embodiment, and is configured to allow the pressure medium to flow from the blank holder 40 and the entire outer periphery of the die 10.
Further, the inner end edge portions of the upper cylindrical portion 12 and the lower cylindrical portion 14 of the die 10 and the outer peripheral edge portions of the inner punch 22 and the outer punch 24 of the punch 20 are chamfered, respectively.
Moreover, although the magnitude | size of the die | dye 10 is arbitrary, in this embodiment, it is as follows. The diameter d1 of the large diameter portion 16 is 1.706 mm, the diameter d2 of the small diameter portion 18 is 0.556 mm, the diameter d3 of the shoulder portion 15 of the stepped portion 15 is 0.575 mm, and the height h1 of the upper cylindrical portion 12 is 2230 mm.
The die and the blank holder can be formed using metal or the like.

<Punch>
As shown in FIGS. 1 and 2, the punch 20 includes a columnar internal punch 22 and a cylindrical external 24 punch that covers the periphery of the internal punch 22 and is arranged on the same axis. The external punch 24 has a large diameter portion. The outer diameter is smaller than the diameter of 16 and larger than the diameter of the small diameter portion 18, and a clearance 30 is provided between the punch 20 and the die 10. The small diameter portion 18 also serves as a flow path through which the pressure medium flows.
The internal punch 22 and the external punch 24 are connected to separate driving devices by a mechanism similar to the device having this type of punch, and can be moved up and down independently. The internal punch 22 is fixed and only the external punch 24 is It is possible to drive in the vertical direction, and the internal punch 22 and the external punch 24 can be simultaneously driven in the vertical direction.
The length of the punch is arbitrary depending on the desired length of the molded body and is not particularly limited, but in the present embodiment, it is as follows. The punch diameter d4 is 1.65 mm, and the inner punch diameter d5 is 0.5 mm.
The punch can be formed by using a rigid fiber, plastic, fiber reinforced plastic (FRP) or the like in addition to a metal for both the internal punch and the external punch.

<Other members>
In the manufacturing apparatus of the present invention, members normally employed in this type of apparatus can be appropriately provided without departing from the spirit of the present invention. For example, the manufacturing apparatus of the present invention described above is installed inside a known multi-axis press, and the external punch, the internal punch, and the blank holder are individually controlled. Thereby, deep drawing can be performed by applying an internal pressure.

<Manufacturing>
Next, the manufacturing method of this invention is demonstrated.
The manufacturing method of the present invention can be performed using the above-described manufacturing apparatus,
A step of placing a base plate between a die and a branch holder and forming a concave body by deep drawing with the punch described above,
A step B of raising the external punch inside the concave body to form a gap with the concave body;
A process C in which an internal pressure is applied between the concave body and the die to remove the gap and make the shape of the concave body conform to the shape of the punch;
It is possible to carry out the step D by simultaneously lowering the punches downward and repeating the step B and the step C a predetermined number of times.
Hereinafter, each process will be described with reference to FIGS.

<Materials and objects>
As a base plate used as a raw material of a desired molded body in the above manufacturing method, a disk-shaped plate made of various metal raw materials can be used. In this case, the metal raw material to be used is not particularly limited, and examples thereof include iron, copper, stainless steel, titanium, and aluminum. Also, plastic materials such as polycarbonate, polypropylene, and polyester can be used.
And the molded object obtained by the manufacturing method of this invention is a hollow molded object of a form as shown in FIG. As shown in FIG. 5, the molded body itself is bottomed, but by cutting at a desired position, it becomes possible to obtain a cylindrical body that is very thin and has a length of 10 times or more the diameter. . The dimensions are shown in FIG. 5 as an example. Here, D is a diameter, and h is a height.

<Process A>
In this step, as shown in FIG. 3A, the punch 20 is entirely pushed downward from the state shown in FIG. 2 to deep-draw the base plate A with the die 10 and the punch 20 to form a concave body. This is a molding step.

<Process B>
Next, as shown in FIG. 3B, in this step, only the external punch 24 is lifted upward to form a gap 100 between the punch 20 and the concave body A ′. At this time, the height h2 for lifting the external punch 24 is arbitrary depending on the thickness of the base plate and the difference in radius between the inner diameter punch 22 and the outer diameter punch 24, but if the gap height is particularly small, The gap height can be set in light of the thickness and performance required of the molded product, such as the ability to deform locally up to the ultimate deformation of the forming material and conversely, if the gap height is large, a large material flow can be obtained. This is very important. In the present invention, from these viewpoints, when the diameter d3 (see FIG. 1) of the stepped portion 15 is 100, it is preferably 2 to 30, and more preferably 2 to 10.

<Process C>
Then, an internal pressure is applied between the concave body A ′ and the die 10 with the external punch 24 on the upper side. As a result, the gap 100 disappears, and the portion of the concave body A ′ immediately below the outer diameter punch 24 flows toward the inner punch 22 to conform to the punch shape.
The internal pressure at this time can be variously adjusted according to the thickness of the base plate, the type of material, the thickness required for the molded body, and the like, but can be set to 100 to 1000 MPa, and preferably 100 to 400 MPa.
The internal pressure can be applied by allowing a pressure medium to flow from the flow path 50 into the clearance 30, the large diameter portion 16, and the small diameter portion 18. The pressure medium is also allowed to flow from the small diameter portion 18. Examples of the pressure medium that can be used in this case include water and various oils. It is also possible to load using a gas such as air instead of a liquid. In this way, it is preferable that each member has a pressure resistance specification in order to load an ultra-high pressure. The ultra high pressure loading method is not limited to static loading, and it may be preferable to perform shock pressing or pulsed repeated pressing because the fluidity of the base plate and the conformability to the punch are improved. This shocking and pulsating pressure can be created by a piston in the ultra-high pressure generator, or by rapid vertical movement of the punch inside the device 1 and the repetition thereof.

<Process D>
Next, as shown in FIG. 3D, the punch 20 is lowered downward as a whole. The external punch 24 is lowered to the extent that it abuts against the shoulder 15 as in the state shown in FIG. As a result, the concave body A ′, which is not familiar with the punch, is lowered to such an extent that it comes into contact with the step portion 15 inside the die. Thereby, by pressing the concave body A ′ against the step portion 15 of the die 10 by the external punch 24, it is possible to adjust the thickness of the concave body A ′ and further flow the material.
<Repetition process>
Then, the process B and the process C are repeated a predetermined number of times in the present embodiment, that is, until the molded body has a desired length.
By repeating each step in this manner, the gap generated by pulling up the external punch (step B) is eliminated by internal pressure (step C), and the entire punch is lowered (step D), and then the external punch is further pulled up. Thus, the internal punch 22 gradually protrudes downward as shown in FIG. 4 so that the molded body 200 is formed on the outer peripheral surface of the internal punch, and the outer diameter of the internal punch 22 is substantially equal to the inner diameter. The formed body 200 can be obtained.

<Conditions common to all processes>
Although the manufacturing method of the present invention can be performed at room temperature, it is easy to work if the temperature inside the manufacturing apparatus is raised to the recrystallization temperature of the material for forming the base plate, so that the manufacturing method should be performed under a condition that is heated to some extent. Is preferred. As a result, even a material having high hardness can be manufactured with good moldability. The temperature is limited by the pressure medium to be used, but when a liquid is used, the upper limit is about 250 ° C. If a gas is used, the production can be performed under a higher temperature condition.
<Other processes>
In step C, when wrinkles due to buckling occur when internal pressure is applied, in step D, the external punch and the internal punch are simultaneously pushed in the wrinkled shape, and the concave body flows into the punch while crushing the wrinkles. It is preferable to increase the squeezing depth in such a way that it can be adapted. By carrying out this series of steps, the low drawability on the microscale can be increased to the limit and deep drawing can be provided.

In addition, in the stage shown in FIG. 2, it is possible to perform a loading process that sequentially repeats the process of pushing the base plate A with the blank holder 40 and the die 10 until the thickness of the base plate A reaches a desired thickness. As a result, it is possible to positively flow the base plate to the large-diameter portion 16 of the die and adjust the plate to a desired thickness as appropriate.
Also, annealing heat treatment can be introduced in the repetition process. This makes it possible to process materials that always maintain the ductility (extreme deformability) of the virgin material, and in the case of steel materials, strengthening by heat treatment (transformation) such as quenching can be performed simultaneously during the process. Become.

<Effect>
According to the manufacturing method of the present invention, it is possible to create an extremely elongated ultra-deep-drawn shaped body that could not be achieved so far, and in particular, molding with a remarkably large slenderness ratio compared to conventional deep-drawn shaped bodies. It can be a body.
Especially for painless injection needles, the productivity and quality can be improved and the cost can be greatly reduced.
The production method of the present invention can be applied not only to micro-scale molded bodies but also to molded bodies having various dimensions.

The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.
For example, in the above-described manufacturing method, an example in which pressurization is performed has been described. However, the present invention is not limited thereto, and the manufacturing apparatus of the present invention can also cope with a molding method without performing pressurization. That is, it is possible to process the molded body by simply pressing the punch against the shoulder so that the concave body fits into the punch.
In the above example, a two-stage structure having a large-diameter portion and a small-diameter portion is shown and described. However, the present invention is not limited to this, and a three-stage or more structure may be used.

1 manufacturing equipment, 10 dies, 12 upper cylindrical part, 14 lower cylindrical part, 15 shoulder part, 16 large diameter part, 17 gap, 18 small diameter part, 20 punch, 22 internal punch, 24 external punch, 30 clearance, 40 blank holder 50 channels

Claims (3)

In a method for producing a molded body having a predetermined shape using a deep drawing molding apparatus comprising a die, a punch, and a blank holder,
The die has a void, the void is columnar, has a large diameter portion with a large diameter, and a small diameter portion with a small diameter connected to the large diameter portion,
The punch includes a columnar internal punch and a cylindrical external punch arranged around the inner punch, and the external punch is smaller than the diameter of the large diameter portion and larger than the diameter of the small diameter portion. Has a diameter,
A step of placing a base plate between a die and a branch holder and performing a deep drawing with the punch to form a concave body,
A step B of lifting the external punch upward inside the concave body to form a gap between the concave body and the punch,
Step C, in which an internal pressure is applied between the concave body and the die to eliminate the gap, and the shape of the concave body conforms to the shape of the punch,
A manufacturing method characterized by performing step D in which the external punch and the internal punch are simultaneously lowered downward, and further repeating step B and step C a predetermined number of times.
Comprising a die having a gap, a punch, and a blank holder installed above the die;
A manufacturing apparatus for performing the manufacturing method according to claim 1,
The voids in the die are columnar and have a large diameter portion with a large diameter and a small diameter portion with a small diameter connected to the large diameter portion,
The punch includes a columnar internal punch and a cylindrical external punch arranged around the inner punch, and the external punch is smaller than the diameter of the large diameter portion and larger than the diameter of the small diameter portion. A manufacturing apparatus having a diameter and having a gap between the punch and the die.
The die has a step portion that forms the large diameter portion and the small diameter portion,
The manufacturing apparatus according to claim 2, wherein the stepped portion includes a chamfered shoulder portion, a flat portion, and a fillet portion.

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