This application claims priority in Hong Kong Patent Application no. 12109551.8, filed 27 Sep. 2012, the contents of which are hereby incorporated by reference.
This invention relates to a metal forming head, a machine with such a head and a metal forming method, in particular such a head, such a machine and such a method for forming sheets of metal.
Metalworking includes forming, cutting and joining of metals. Forming processes are carried out to modify metal or workpiece by deforming the object, i.e. without removing any material. Forming is done with heat and pressure, or with mechanical force, or all of them. In some such forming procedure, e.g. stamping, while not removing any material from the metal workpiece (e.g. sheets of metal), some part of the metal has to be cut off from some other part of the metal. In conventional methods for stamping thin sheets of metal (e.g. a copper sheet of a thickness of around 0.1 mm, an aluminum sheet of a thickness of around 2 mm, or a stainless steel sheet), as the sheets of metal are very thin, they cannot be held under sideway tensioning force (i.e. tension force acting in a direction parallel to the plane of the sheet of metal). It is found that, under such circumstances, the cutting effect is not satisfactory, in that some of the cut off edges are not clean.
It is thus an object of the present invention to provide a metal forming head, a machine with such a head and a metal forming method in which the aforesaid shortcomings are mitigated or at least to provide useful alternatives to the trade and public.
According to a first aspect of the present invention, there is provided a metal forming head including a die with a forming portion, and a die holder with a hole therethrough and an abutment surface, wherein at least part of said forming portion of said die is receivable through said hole of said die holder, wherein said die holder is movable relative to a workpiece between a first position in which said abutment surface of said die holder abuts and applies a force on a major surface of said workpiece and a second position in which said abutment surface of said die holder is out of abutment with said major surface of said workpiece, and wherein, when said abutment surface of said die holder abuts said major surface of said workpiece, said die is movable relative to said abutment surface of said die holder to form said workpiece.
According to a second aspect of the present invention, there is provided a metal forming machine including at least one metal forming head, said metal forming head including a die with a forming portion, and a die holder with a hole there-through and an abutment surface, wherein at least part of said forming portion of said die is receivable through said hole of said die holder, wherein said die holder is movable relative to a workpiece between a first position in which said abutment surface of said die holder abuts and applies a force on a major surface of said workpiece and a second position in which said abutment surface of said die holder is out of abutment with said major surface of said workpiece, and wherein, when said abutment surface of said die holder abuts said major surface of said workpiece, said die is movable relative to said abutment surface of said die holder to form said workpiece.
According to a third aspect of the present invention, there is provided a metal forming method, including (a) positioning a sheet of metal in a working position; (b) applying a first force on said sheet of metal in a direction substantially perpendicular to a major surface of said sheet of metal, and (c) forming said sheet of metal by applying a second force on said sheet of metal in said direction.
A metal forming head, a machine with such a head and a metal forming method according to the present invention will now be described, by way of examples only, with reference to the accompany drawings, in which:
Referring firstly to
Locked holders are carried and conveyed by carriers 12a, 12b, 12c, 12d, in which the holders are stacked one above another. In
When the locked holder 13d (which is formed of a cover and a base, and to be further discussed below) is on the second working platform 24, the locked holder 13d is un-locked, allowing the cover to be released and detached from the base. The first robot arm 20 then picks up (e.g. by a number of claws) the cover. A second robot arm 28 then picks up (e.g. by suction) a sheet of metal, such as a copper foil (which may of a thickness of around 0.1 mm), an aluminum foil (which may be of a thickness of around 2 mm) or a stainless steel sheet, and places it on the base of the holder 13d. When the sheet of metal is properly positioned on the base of the holder 13d, the first robot arm 20 then places the cover back on to the base (thus engaging the sheet of metal in between). When the positioning of the sheet of metal 36 is found by a camera to be correct and the cover 50 and the base 40 are found to be properly aligned with each other, the holder 13d is then locked again to securely hold the sheet of metal 36. A third robot arm 29 (see
The locked and loaded holder 13d is then pushed into a carrier 12c which is movable vertically through an aperture in a working table 18. More particularly, locked and loaded holders are moved consecutively into the carrier 12c which moves intermittently downwardly to allow locked and loaded holders to be conveyed into the carrier 12c at the same level on or above the working table 18. Such locked and loaded holders are then conveyed to a carrier 12d for output.
On a front side of the carrier 12 is provided a strip of side door 35 which may be caused to pivot by movement of a knob 37. More particularly, the knob 37 may be moved to pivot the side door 35 between a closed position in which the side door 35 closes part of the front side of the carrier 12 and an open position in which the side door 35 is pivoted away from the closed position by at least around 90°. When the side door 35 is in the closed position, the holders 13 in the carrier 12 cannot be retrieved from the carrier 12; whereas when the side door 35 is in the open position, the holders 13 in the carrier 12 can be retrieved from the carrier 12.
It can be seen in
A top perspective view of a sheet of metal 36 (being a workpiece to be held by the holder 13), with an upper major surface 38a and an opposite lower major surface 38b, is shown in
As shown in
One a lower surface of the cover 50 are also provided with two perpendicular slots for receiving the portions of the two strips of plastic material 42a, 44a which extend above the upper surface 46 of the base 40. Such an arrangement allows for easy and precise alignment of the cover 50 and the base 40.
The base 40 has four rims 48a, 48b, 48c, 48d joined with one another in a generally rectangular shape, and thus with four corners. When the sheet of metal 36 is placed on the base 40, part of the lower major surface 38b of the sheet of metal 36 contacts the rims 48a, 48b, 48c, 48d.
As to the cover 50, it also has four rims 52a, 52b, 52c, 52d joined with one another in a generally rectangular shape, and again with four corners. When the sheet of metal 36 is properly placed and positioned on the base 40, the cover 50 may be placed on the sheet of metal 36, such that part of the upper major surface 38a of the sheet of metal 36 contacts the rims 52a, 52b, 52c, 52d of the cover 50. It can be seen that when the sheet of metal 36 is thus held by the holder 13 and between the cover 50 and the base 40, a major proportion of the upper major surface 38a of the sheet of metal 36 is exposed to the outside environment, for subsequent working.
Adjacent each of the four corners of the carrier 13 is a locking mechanism 54 which extends through the base 40 and the cover 50.
As shown more clearly in
As to the lower part 58, such includes an outer generally cylindrical hollow part 58a, a inner spindle 58b, a spring 58c, a side screw 58d and a pin 58e. When the side screw 58d is inserted into the base 40 in the position as shown in
The inner spindle 58b is movable relative to the outer hollow part 58a along the axis P-P between a lowered position (as shown in
The inner spindle 58b is also rotatable relative to the outer hollow part 56a of the upper part 56 and the outer hollow part 58a of the lower part 58 about the axis P-P. It can be seen that the pin 58e, which is carried by the inner spindle 58b for simultaneous movement, is elongate and extends in a direction perpendicular to the axis P-P. Rotation of the inner spindle 58b relative to the outer hollow part 58a will cause corresponding rotation of the pin 58e relative to the outer hollow part 58a.
To unlock the carrier 13, the inner spindle 58b is first pushed further into the outer hollow part 56a of the upper part 56, and is then rotated by 90° (in either direction) relative to the outer hollow part 58a, to turn the pin 58e by the same angle, whereby the pin 58e is removed from the troughs 60 and in a position relative to the outer hollow part 58a in which the inner spindle 58b is then allowed to be moved to the lowered position under the biasing force of the spring 56c. In particular, the inner spindle 58b is shown in the lowered position in
After the stamping action, a second robot arm 114 picks up (e.g. by a number of claws) the holder 13 with the stamped sheet of metal 36 from the second working platform 112 and places it on a third working platform 116. The holder 13 is then moved from the third working platform 116 into a carrier 12b resting on a movement platform 116. The movement platform 116 is movable up and down through a hole 120 through the working table 106, for subsequent output of the carrier 12b carrying locked holders 13 each holding a stamped sheet of metal 36.
A monitoring camera 122 is positioned next to where the holder 13 should be positioned for the stamping step, to determine whether the second working platform 112, the holder 13 and the sheet of metal 36 held by the holder 13 are properly positioned before each stamping action. If not, the second working platform 112 is moved in either or both the x-direction and y-direction to correctly position the holder 13 and the sheet of metal 36 held by it.
After stamping, the holder 13 with the stamped sheet of metal 36 is moved by the second robot arm 114 to the third working platform 116, to be subsequently moved into the carrier 12b. Once a holder 13 is moved into the carrier 12b, the carrier 12b is lowered through the hole 120 of the working table 106 by a pre-determined height to allow space for reception of a subsequent holder 13.
Each of the intermediate part 127 and the abutment part 138 of the die holder 126 has a rectangular through hole, which, when the stamping head 113 is properly installed, collectively form a through hole 136 for receiving there-through the stamping portion 130 of the stamping die 124 for relative movement. In particular, the stamping portion 130 of the stamping die 124 is movable within and relative to the through hole 136 upwardly and downwardly in the direction of the bi-directional arrow W-W, e.g. for stamping the sheet of metal 36. The allowed distance of downward movement of the stamping die 124 relative to the abutment part 138 of the die holder 126 is the distance by which the intermediate part 127 of the stamping die 124 is spaced apart from the abutment part 138 of the die holder 126 when the stamping die 124 is in its upper spring-biased position.
As shown in
For stamping the sheet of metal 36 held in the holder 13, the holder 13 is positioned such that a first area (called “working area”) of the sheet of metal 36 to be worked on is below the stamping head 113. The stamping head 113 is then moved downwardly towards the sheet of metal 36 until the bottom surface 144 (which faces away from the die 124) of the bottom 142 of the abutment part 138 of the die holder 126 just abuts and exerts a slight stabilizing force on the sheet of metal 36, downwardly in a direction indicated by the arrow D in
While maintaining the abutment between the abutment part 138 and the sheet of metal 36 and thus the stabilizing force on the sheet of metal 36, the stamping die 124 is moved from its upper spring-biased position (in which the forming portion 130 of the die 124 does not extend through a plane containing the bottom surface 144 of the abutment part 138) simultaneously with the bolts 132 and the intermediate part 127 of the die holder 126, downwardly relative to the abutment part 138 of the die holder 126 and against the upwardly biasing force of the springs 134, to move the stamping portion 130 downwardly to a lower position relative to the die holder 126 (in which the intermediate part 127 comes into contact with the abutment part 138 of the die holder 126 and the forming portion 130 extends through the plane containing the bottom surface 144 of the abutment part 138) to stamp the sheet of metal 36, to thereby exert a second downward force (in the same direction as indicated by the arrow D in
The second downward force for forming the sheet of metal 36 is applied while the stabilizing force is still being applied on the sheet of metal 36. In addition, the second downward force for forming the sheet of metal 36 is larger than the stabilizing force.
After stamping, the stamping die 124 is returned to its upper position by the upward biasing force of the springs 134. The holder 13 is then moved so that a second working area of the sheet of metal 36 is below the stamping head 113 for subsequent stamping, until all the necessary working areas of the sheet of metal 36 are stamped.
It is found in practice that, with the application of a stabilizing force on the sheet of metal 36 during stamping, the quality of stamping is enhanced, with less undesirable tearing effect.
It can also be seen that by way of the present invention, the efficiency of the stamping process is improved and precise positioning of sheets of metal for stamping can be achieved.
It should be understood that the above only illustrates examples whereby the present invention may be carried out, and that various modifications and/or alterations may be made thereto without departing from the spirit of the invention. In particular, it should be understood that, in this document, the word “metal” is intended to cover “metal alloy” as well.
It should also be understood that certain features of the invention, which are, for clarity, described in the context of separate embodiments, may be provided in combination in a single embodiment. Conversely, various features of the invention which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any appropriate sub-combinations.
Number | Date | Country | Kind |
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HK12109551.8 | Sep 2012 | HK | national |