WO2016061708A1

WO2016061708A1 - Fine extru-cutting forming machine

Info

Publication number: WO2016061708A1
Application number: PCT/CN2014/000924
Authority: WO
Inventors: Cheng-Ping Wang
Original assignee: Cheng-Ping Wang
Priority date: 2014-10-21
Filing date: 2014-10-21
Publication date: 2016-04-28
Also published as: CN107206446A

Abstract

A fine extru-cutting forming machine for extruding/cutting a billet comprises a container (20) having opposing open ends (22), a die (10) placed at one of the open ends, and a pressing module (30) comprising a ram (31) and a punch (32). The ram is adapted to move axially in the container and have an axial opening (33) for receiving the punch. The punch is adapted to move axially in the ram. The punch has a negative clearance with the die. The forming machine can manufacture the precision products which is suitable for mass production without cost increase. Also provided is a method for forming a product using the fine extru-cutting forming machine.

Description

FINE EXTRU-CUTTING FORMING MACHINE

FIELD OF THE INVENTION

The present invention relates to a fine extru-cutting forming machine， and more particularly to a fine extru-cutting forming machine which combines the process of extrusion， cutting and forming.

BACKGROUND OF THE INVENTION

Extrusion is one of the oldest metal forming processes in industry. Owing to its complicated aspects， such as the effect of die profiles， material characteristics， friction and tribological conditions， the techniques of extrusion therefore are an area of interest for many researchers.Extrusion is a process by which billet of a material is reduced in cross-section by pushing or drawing it through a die of the desired cross-section， to produce objects of a fixed cross-sectional profile. As shown in Figure 1 (prior art) ， a conventional (direct) extrusion device/system comprises a ram 50， a container 51， and a die 52， for extruding a billet 53. A dummy block 54 may be further included. In the extrusion process， the billet 53 may be heated and then loaded into the container 51， and the dummy block 54 may be placed at the end of the ram 50 in contact with the billet 53， where the ram 50 then presses on the billet 53 to push it out of the die 52.

In practical use， conventional extrusion processes still have many problems need to be solved， for example： (1) the surface of the extrusions may be rough due to great frictions between the billet and the die； and (2) the precision of the extrusions does not meet the requirements for precision industries. Put it simply， conventional extrusion is only suitable for the production of relatively rough products such as rails， steel bars for construction， and structural parts for ship and airplane. However， certain important industrial products such as gear， pump， motor rotor， and precision parts for machine tool cannot be produced by conventional extrusion processes. US 8015851 B2 discloses a press forming method by using a punch having a negative clearance with a die. However， it is silent as to extrusion forming or cutting.

In view of the foregoing， it is urgently desired in this industry to develop a machine for manufacture of precision products which is suitable for mass production without cost increase.

SUMMARY OF THE INVENTION

In one aspect， the present invention provides a fine extru-cutting forming machine for extruding/cutting a billet， comprising a container having opposing open ends， a die placed at one of the open ends， and a pressing module. The die has an opening therein or a cavity thereon. The pressing module includes a ram and a punch. The ram is adapted to move axially in the container and has an axial opening for receiving the punch， and the punch is adapted to move axially in the ram. The fine extru-cutting forming machine is characterized in that the punch has a negative clearance with the die. However， the present invention also contemplates the case of positive clearance.

In one embodiment of the present invention， the fine extru-cutting forming machine further comprises a first trough structure formed on the die at its billet contacting side， wherein the first trough structure is formed surrounding the opening or cavity of the die.

According to another embodiment of the present invention， the fine extru-cutting forming machine further comprises a second trough structure formed on the ram at its billet contacting side， wherein the second trough structure is formed surrounding the axial opening of the ram.

According to certain embodiments of the present invention， the first trough structure may further include a first filler module disposed therein， and the second trough structure may also include a second filler module disposed therein.

In one embodiment of the present invention， the punch has a sectional area larger than that of the opening or cavity of the die， such that the punch has a negative clearance with the die.

In another embodiment of the present invention， the punch has a sectional area smaller than that of the opening or cavity of the die， such that the punch has a positive clearance with the die.

In one embodiment of the present invention， the fine extru-cutting forming machine further comprises a motor for applying a rotational force to the container， allowing at least part of the container and the die to rotate axially. A fine extru-cutting forming machine of the present invention configured with a motor may be used to form products having spiral shape， such as helical screws， helical gears， worm screws， and worm gears， etc.

In certain embodiments of the present invention， the opening or cavity has a bevel shape in the die or an initially generally cylindrical shape to a bevel shape in the die， for forming products such as bevel screws and bevel gears. In one embodiment， the opening or cavity has an initial shape of the outline of a spur gear towards a shape of the outline of a bevel gear in the die.

In one embodiment of the present invention， the container is sealably close with the die.

In another aspect， the present invention provides a method for forming a product， comprising： in a machine comprising a container having opposing open ends， a die placed at one of the open ends and having an opening therein or a cavity thereon， and a pressing module including a ram and a punch， the ram being adapted to move axially in the container and having an axial opening for receiving the punch， the punch being adapted to move axially in the ram， wherein the punch has a negative clearance with the die， the ram applying a ram force to a billet loaded in the container to press the billet toward the die； and the punch applying a punch force to the billet to penetrate therein and cause part of the billet to enter the opening or cavity of the die.

The detailed technology and preferred embodiments implemented for the subject invention are described in the following paragraphs accompanying the appended drawings for people skilled in this field to well appreciate the features of the claimed invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing summary， as well as the following detailed description of the invention， will be better understood when read in conjunction with the appended drawing. In the drawings：

Figure 1 shows a schematic cross-sectional view of a conventional extrusion machine.

Figure 2 shows a schematic cross-sectional view of a fine extru-cutting forming machine in accordance with one embodiment of the present invention.

Figure 3 shows a perspective view of the fine extru-cutting forming machine of said embodiment.

Figure 4 shows an exploded view of the fine extru-cutting forming machine of said embodiment.

Figure 5 shows a schematic cross-sectional view of a fine extru-cutting forming machine in accordance with one preferred embodiment of the present invention.

Figure 6 shows a perspective view of the fine extru-cutting forming machine of said preferred embodiment.

Figure 7 shows an exploded view of the fine extru-cutting forming machine of said preferred embodiment.

Figure 8 shows a schematic cross-sectional view of a fine extru-cutting forming machine in accordance with another embodiment of the present invention.

Figure 9 shows a perspective view of the fine extru-cutting forming machine of said embodiment.

Figure 10 shows an exploded view of the fine extru-cutting forming machine of said embodiment.

Figure 11 shows a perspective view of a fine extru-cutting forming machine in accordance with one embodiment of the present invention.

Figure 12 shows an exploded view of the fine extru-cutting forming machine of said embodiment.

Figure 13 shows a perspective view of a fine extru-cutting forming machine in accordance with another embodiment of the present invention.

Figure 14 shows an exploded view of the fine extru-cutting forming machine of said embodiment.

DESCRIPTION OF THE INVENTION

Unless defined otherwise， all technical and scientific terms used herein have the same meaning as commonly understood by a person skilled in the art to which this invention belongs.

As used herein， the singular forms “a” ， “an” ， and “the” include plural referents unless the context clearly dictates otherwise. Thus， for example， reference to “a sample” includes a plurality of such samples and equivalents thereof known to those skilled in the art.

In one aspect， the present invention provides a fine extru-cutting forming machine for extruding/cutting a billet， comprising： a container having opposing open ends； a die having an opening therein or a cavity thereon， placed at one of the open ends； and a pressing module comprising a ram and a punch， the ram being adapted to move axially in the container and having an axial opening for receiving the punch， the punch being adapted to move axially in the ram； wherein the punch has a negative clearance with the die. In certain embodiments， the container is sealably close with the die， as that for a conventional extrusion machine.

Referring to Figures 2-4， shown is a fine extru-cutting forming machine of the present invention， comprising a die 10， a container 20， and a press module 30. The container has opposing open ends 22. The die 10 is placed at one of the open ends 22， and has an opening 11 that penetrates there-through. The opening 11 has a shape (i.e.， horizontal sectional shape) of the desired cross-section of the product to be formed. The press module 30 comprises a ram 31 and a punch 32. The ram 31 is adapted to move along the axial direction of the container 20 inside the container 20. The ram 31 has an axial opening 33 for receiving the punch 32， and the punch 32 is adapted to move axially therein. This fine extru-cutting forming machine may be used to extruding/cutting a billet 23. To be noted， the punch 32 has a negative clearance with the die 10. In other words， similar to the ram 50 for conventional extrusion forming (see Figure 1) ， the punch 32 does not enter the opening 11 of the die 10. In certain other embodiments of the present invention， the die may instead have a cavity formed thereon (i.e.， not penetrated) .

Unlike conventional cutting machine whose punch has a zero or positive clearance with the die， the extru-cutting forming machine of the present invention is characterized in that it comprises a punch having a negative clearance with the die. In one embodiment of the present invention， the punch has a sectional area larger than that of the opening of the die. A conventional cutting machine or blanking machine may only be used to manufacture a product with a thickness of around 5 mm. However， a fine extru-cutting forming machine of the present invention may form a product with a thickness of more than 10 mm.

Unlike the press forming device as disclosed in US 8015851 B2 which comprises a counter pad 6 disposed in the die (see Fig. 5 of US 8015851 B2) ， the extru-cutting forming machine of the present invention does not comprise a counter pad. Further， since the device disclosed in US 8015851 B2 is for “press forming” ， it comprises a stripper plate 5 for fixing a workpiece 4 in position， instead of a ram for applying a ram force to a billet.

Although featuring a fine extru-cutting forming machine comprising a punch has a negative clearance with the die， the present invention also contemplates the case of positive clearance.

As can be seen in Figures 5-10， a fine extru-cutting forming machine of the present invention may further comprise a trough structure formed on the die 10 or the ram 31. As shown in Figures 5-7， a first trough structure 21 is formed on the die 10 at the side where it would contact with the billet 23. Further， the first trough structure 21 is formed surrounding the opening 11 of the die 10. Referring to Figures 8-10， a second trough structure 22 may be further formed on the ram 31 at the side where it would contact with the billet 23 and is formed surrounding the axial opening 33 of the ram 31.

The term “trough structure” as used herein refers to a trough-， concave-， or ladder-shape structure formed on the die and/or the ram of a fine extru-cutting forming machine of the present invention. The configuration of a trough structure is not limited herein. A person having ordinary skill in the art can readily determine an appropriate configuration， e.g.， U shaped or V shaped trough structure. Neither the surrounding shape of the trough structure is limited herein. A person having ordinary skill in the art can readily determine an appropriate shape suitable for a specific product. Preferably， the shape may be circular or a shape that corresponds to the shape of the opening of the die. The trough structure may be formed on the die at the edge of the billet contacting side thereof and/or formed on the ram at the edge of the billet contacting side thereof. The trough structure may also be formed at an appropriate position between the outer edge of the die and the outlet of the opening， and/or between the outer edge of the ram and the outlet of the axial opening. In summary， what is required is a space surroundingly formed on the die and/or the ram at its billet contacting side.

In one embodiment of the present invention， a fine extru-cutting forming machine of the present invention may further comprise a filler module disposed in the trough structure. The function of the filler module is to keep pressure uniformly in the trough structure when the press module 30 moving downward to extrude/cut the billet 23. With reference to Figures 5 and 8， a first filler module 24 may be disposed in the first trough structure 21 and/or a second filler module 25 may be disposed in the second trough structure 22.

The filler module can be of hydraulic pressure type， air pressure type， spring， O ring， soft material， hard material， etc. The filler module can keep pressure uniformly in the trough structure and further improves the quality of extru-cutting products. In one embodiment of present invention， the first filler module 24 and the second filler module 25 are the same type of the filler module. In another embodiment of present invention， the first filler module 24 and the second filler module 25 are not the same type of filler module.

Please refer to Figures 2-10 again. When the fine extru-cutting forming machine starts the extrusion/cutting process， the ram 31 moves axially in the container 20 and presses on the billet 23 toward the die 10. At the present stage， little of the billet 23 may enter the opening 11 of the die 10. Then the punch 32 moves axially along the axial opening 33 of the ram 31 and applies a punch force to the billet 23 to penetrate therein and cause part of the billet 23 to enter the opening 11 of the die 10.

Please refer to Figures 11 and 12 in accordance with certain other embodiments of the present invention. In these embodiments， the fine extru-cutting forming machine of the present invention further includes a motor， e.g. a servo motor. Further， the container 20 may comprise an upper portion 26 and a lower portion 27. The motor is configured to apply a rotational force to the lower portion 27 of the container 20， allowing the lower portion 27 and the die 10 to rotate axially. By rotating the die in the forming process， the fine extru-cutting forming machine of the present invention can be used to form products having spiral shape， such as helical screws， helical gears， worm screws， and worm gears， etc.

According to certain embodiments of the present invention， for the manufacture of products such as bevel screws and bevel gears， etc.， the opening or cavity of the die is configured to have a bevel shape or an initially generally cylindrical shape (or round shape) to a bevel shape in the die. In other words， the opening or cavity may have a longitudinal sectional shape of bevel (or trapezoidal) shape or a hexagonal shape. Referring to Figures 13 and 14 in accordance with one specific embodiment of the present invention， the opening 11 has a horizontal sectional shape of gear while has a bevel shape in the die 10. More particularly， the opening 11 shrinks along the direction where the punch 32 moves toward the die 10. For the manufacture of bevel gears， the opening preferably has an initially generally cylindrical shape to a bevel shape in the die. Specifically， the opening has an initially consistent diameter and then shrinks along the direction where the punch moves toward the die. More specifically， for the manufacture of bevel gears， the opening or cavity has an initial shape of the outline of a spur gear towards a shape of the outline of a bevel gear in the die. Of course， a motor may be further included in the fine extru-cutting forming machine if die rotation is desired in the forming process.

For all the embodiments mentioned above， the opening 11， the punch 32 and the axial opening 33 are expressed as round shape. However， the shapes of the opening， cavity， punch， and axial opening are not limited herein. In certain embodiments of the present invention， the punch and the opening or cavity may have different horizontal sectional shapes， and the opening or cavity may have different shapes in the die (i.e. different longitudinal sectional shapes) .

Generally， the ram (and/or the dummy block) of a conventional extrusion machine has a sectional area substantially equal to that of the die (i.e.， larger than that of the opening in the die) ， and the punch of a conventional blanking (cutting) machine has a sectional area equal to or smaller than that of the opening in the die (i.e. with zero or positive clearance with the die) .

It is worth to note that the fine extru-cutting forming machine of the present invention structurally more resembles a conventional cutting/blanking machine， while in purpose more resembles a conventional extrusion machine because it can be used to form a more elongated product as compared with the cutting/blanking process.

In another aspect， the present invention provides a method for forming a product， comprising： in a machine comprising a container having opposing open ends， a die placed at one of the open ends and having an opening therein or a cavity thereon， and a pressing module including a ram and a punch， the ram being adapted to move axially in the container and having an axial opening for receiving the punch， the punch being adapted to move axially in the ram， wherein the punch has a negative clearance with the die， the ram applying a ram force to a billet loaded in the container to press the billet toward the die； and the punch applying a punch force to the billet to penetrate therein and cause part of the billet to enter the opening or cavity of the die， thereby forms the product. The formed product may then be cut out from the billet. In certain embodiments of the present invention， the billet (product) is extruded out of the die. In other embodiments， the product is formed in the die (for example， products such as bevel gears) .

To be noted， the present invention further contemplates an alternative embodiment that the punch has a positive clearance with the die.

In one embodiment of the present invention， the fine extru-cutting forming machine further comprises a first trough structure formed， surrounding the opening or cavity， on the die at the billet contacting side thereof. Preferably， the first trough structure further includes a first filler module disposed therein. In another embodiment， the fine extru-cutting forming machine further comprises a second trough structure formed， surrounding the axial opening， on the ram at the billet contacting side thereof. Similarly， the second trough structure may further include a second filler module disposed therein. When the ram applies a ram force to a billet loaded in the container to press the billet toward the die， some billet material will be pressed into the first trough structure and/or the second trough structure.

According to one preferred embodiment of the present invention， the punch has a sectional area larger than that of the opening or cavity of the die (i.e.， negative clearance) .

In another embodiment， the punch has a sectional area smaller than that of the opening or cavity of the die (i.e.， positive clearance) .

According to one embodiment of the present invention， the method further comprises the following step： when applying the punch force， a motor applying a rotational force to the container， allowing at least part of the container and the die to rotate axially.

In certain embodiments of the present invention， the opening or cavity used in the method of the present invention has a bevel shape or an initially generally cylindrical shape to a bevel shape in the die to manufacture products such as bevel screws and bevel gears. In one preferred embodiment， the opening or cavity has an initially generally cylindrical shape to a bevel shape in the die. Specifically， the opening or cavity has an initial shape of the outline of a spur gear towards a shape of the outline of a bevel gear in the die.

It is believed that a person of ordinary knowledge in the art where the present invention belongs can utilize the present invention to its broadest scope based on the descriptions herein with no need of further illustration. Therefore， the descriptions and claims as provided should be understood as of demonstrative purpose instead of limitative in any way to the scope of the present invention.

Claims

A fine extru-cutting forming machine for extruding/cutting a billet， comprising：

a container having opposing open ends；

a die having an opening therein or a cavity thereon， placed at one of the open ends； and

a pressing module including a ram and a punch， the ram being adapted to move axially in the container and having an axial opening for receiving the punch， the punch being adapted to move axially in the ram；

wherein the punch has a negative clearance with the die.
The fine extru-cutting forming machine of claim 1， further comprising a first trough structure formed， surrounding the opening or cavity， on the die at the billet contacting side thereof.
The fine extru-cutting forming machine of claim 1， further comprising a second trough structure formed， surrounding the axial opening， on the ram at the billet contacting side thereof.
The fine extru-cutting forming machine of claim 2， wherein the first trough structure further includes a first filler module disposed therein.
The fine extru-cutting forming machine of claim 3， wherein the second trough structure further includes a second filler module disposed therein.
The fine extru-cutting forming machine of claim 1， wherein the punch has a sectional area larger than that of the opening or cavity of the die.
The fine extru-cutting forming machine of claim 1， wherein the container is sealably close with the die.
The fine extru-cutting forming machine of claim 1， further comprising a motor for applying a rotational force to the container， allowing at least part of the container and the die to rotate axially.
The fine extru-cutting forming machine of claim 8， wherein the motor is a servo motor.
The fine extru-cutting forming machine of claim 1， wherein the opening or cavity has a bevel shape in the die.
The fine extru-cutting forming machine of claim 1， wherein the opening or cavity has an initial shape of the outline of a spur gear towards a shape of the outline of a bevel gear in the die.
A method for forming a product， comprising：

in a fine extru-cutting forming machine according to claim 1， the ram applying a ram force to a billet loaded in the container to press the billet toward the die； and

the punch applying a punch force to the billet to penetrate therein and cause part of the billet to enter the opening or cavity of the die.
The method of claim 12， wherein the fine extru-cutting forming machine further comprises a first trough structure formed， surrounding the opening or cavity， on the die at the billet contacting side thereof.
The method of claim 13， wherein the first trough structure further includes a first filler module disposed therein.
The method of claim 12， wherein the fine extru-cutting forming machine further comprises a second trough structure formed， surrounding the axial opening， on the ram at the billet contacting side thereof.
The method of claim 15， wherein the second trough structure further includes a second filler module disposed therein.
The method of claim 12， wherein the punch has a sectional area larger than that of the opening or cavity of the die.
The method of claim 12， further comprising the following step：

when applying the punch force， a motor applying a rotational force to the container， allowing at least part of the container and the die to rotate axially.
The method of claim 12， wherein the opening or cavity has a bevel shape in the die.
The method of claim 12， wherein the opening or cavity has an initial shape of the outline of a spur gear towards a shape of the outline of a bevel gear in the die.