stampo per lamiera

[corsaro33]

Good morning,

I press that I have no experience in this field,
I wanted to ask if it is possible to make a mold to bend + drill
in one operation the attached sheet. . .
until today we have done this particular with bending machine + punching machine,
this procedure consists of 3 piege and 2 holes with relative movements of the piece.
as we do about 5000 pieces a year we were thinking
to a mold-type solution.
the sheet has 5mm thickness and is a soft iron.

 

[ziotoy]

you could also do, all in one shot. .. also depends on the tolerance you have on those d16 holes as being so close to the folds could indeed almost certainly ovalize.so it would be the case to think of two molds, one bending and one drilling.
Moreover, given the size of the piece and its thickness, it is also necessary to evaluate the volumes (quantities) of pieces printed over the years and to understand whether it is worth making you mold or to continue doing them as you are already doing.
5000 pcs. the year are few and the molds seen the size have a certain cost qunidi just make some accounts.
clearly in order to make them you need a quote on the cost of the molds.
Say hi.

 

[cliff23]

in my opinion, not considering any costs, you could do
with a double effect mold (see attachment), starting from the painting
on his profile. You just have to calculate the strength of the springs well.

 

[corsaro33]

Hello, Uncle

on the tolerances of the folds there is no problem even for the holes,
the bolt crossing the piece is a m14 consequently plays 2mm,
for the cost of the mold, we thought to realize it,
since in this period the workshop is almost stopped.
Can you give me information about how drilling normally works?
that is, first the sheet bends and then the punches intervene?

 

[corsaro33]

Hello cliff23,

first of all thanks for lighting,
Your sketch is very clear but I don't understand
what year role the lower extractor and relative springs?
In addition, are you using a cup spring?

 

[ziotoy]

the design of cliff for those who understand of sheet metal is explanatory.
the lower mobile extractor serves to go to take the sheet up when it is still flat (open flash).
the upper mobile punch hangs the sheet rested on the extractor and having a greater load of springs than the lower one makes the extractor yields (scende) and therefore the sheet is "adagy" in the fold matrix.
the mobile punch will have such a stroke to make the bending first and then the drilling.Your mobile extractor therefore will also act as a tip (holes).
Keep in mind that as already mentioned, given the size and thickness of the sheet I do not think you can use the springs...I think there is a need for nitrogen cylinders that have a much but much greater power.
Say hi.
Uncle

 

[corsaro33]

thanks Uncletoy for the interesting explanation,
I didn't realize it worked like that!
I thought the lower extractor needed only
to unlock the sheet to the retraction of the upper punch!
Now I've got the problem and I'll tell the boss
that you do in that mold will produce only
I'm afraid of euri!

Bye to resent

 

[cliff23]

the design of cliff for those who understand of sheet metal is explanatory.
the lower mobile extractor serves to go to take the sheet up when it is still flat (open flash).
the upper mobile punch hangs the sheet rested on the extractor and having a greater load of springs than the lower one makes the extractor yields (scende) and therefore the sheet is "adagy" in the fold matrix.
the mobile punch will have such a stroke to make the bending first and then the drilling.Your mobile extractor therefore will also act as a tip (holes).
Keep in mind that as already mentioned, given the size and thickness of the sheet I do not think you can use the springs...I think there is a need for nitrogen cylinders that have a much but much greater power.
Say hi.
Uncle

quoto in full uncle toy, and I add that the extractor will have a race equal to make it reach the matrix plan so as to be able to support the development in plan of the particular referring it with thorns on the profile. Moreover the operator will be facilitated in the extraction of the piece from the mold because it will be expelled from the extractor, even if by experience I would say that it will be easily stuck on the punch, but it will be enough to place spring expellers on the same.

 

[corsaro33]

thank you guys for the answers,
I learned something new!
must be a nice field molding especially from surely
satisfaction.
to resent

 

[judy]

Good morning to all,

I also have a question about molds.
how do I calculate the strength of the compression spring, having the pulling force? or which is the reality between both.

Thank you so much!

 

[cliff23]

Good morning to all,

I also have a question about molds.
how do I calculate the strength of the compression spring, having the pulling force? or which is the reality between both.

Thank you so much!

Hi.
usually, as usual, on a trance the overall strength of
springs acting on the primer is 10% of the pulling effort.
then:

stretching effort= beam perimeter * thicker* kt (material cut resistance)
premilamiera= 10% chopping effort

the tonnage of the press to be used is obtained by adding the pulling effort with the primer.

It should be quite clear, even though practical experience is still the best.

 

[EVO]

Hi.
I do not know if you use a cad and possibly what you use, I wanted to inform you that, for example, visi progress (of the truth) has the calculation of the pulling efforts and the automatic calculation of the springs, it utilises a soft catalog (cortignon) and already proposes the springs subdivided by load (color) and quantity.