Punch press

Details Punch press Punch press

2002-07-10

2004-01-13

Tolan, Ed (Department: 3725)

Metal deforming

With means to handle work or product

Including means to permit maneuvering of work or product at...

C072S020100, C072S020300, C100S048000, C100S216000

Reexamination Certificate

active

06675628

ABSTRACT:

FIELD OF THE INVENTION
The present invention relates to a punch press which makes holes in a plate material and forms it after moving the plate material to a punching process part.
BACKGROUND OF THE INVENTION
An NC unit usually controls the punch press to punch the plate material after stopping it at the predetermined process position, however the cycle time becomes longer and the hit rate becomes lower if waiting for the plate material to be completely stopped.
As illustrated in a plate material transfer speed and a motor speed in driving a ram of
FIG. 9
, the punch motion is started and the punch goes down before a table unit stops to transfer the plate material for improving the above problem. Additionally, as illustrated in a crank angle of
FIG. 8
, this is an example of reciprocating a crank mechanism. The crank mechanism is reciprocated between a waiting position HH1′ in front of contacting a punch tool with the plate material and a pullout position HH2′ wherein the punch tool is apart from the plate material after punching through a bottom dead center BDC but it does not pass through a top dead center TDC.
There is a problem in the above control that the ram must be accelerated rapidly and the energy in driving the motor is increased though the hit rate is improved.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a punch press which can realize high hit rate and energy saving in a punch drive.
It is another object of the present invention to realize high hit rate and energy saving by the simple control wherein the calculation load in a control system is low.
It is a further object of the present invention that a ram can move up and down smoothly when not punching and it excels at absorbing vibration and shock.
It is an additional object of the present invention to provide a plate material transfer/punch motion control program which can realize high hit rate and energy saving in the punch drive.
The present invention will be described with reference to
FIG. 1
corresponding to a preferred embodiment of the present invention. This punch press makes holes and/or forms with a punch tool
6
. This punch press comprises a plate material transfer means
3
for transferring a plate material W, a punch drive means
9
having a rotational/linear motion conversion mechanism
20
that converts the rotation of a servomotor
19
into the rise and fall of a ram
8
which makes the servomotor
19
a driving force and moves the punch tool
6
up and down by the ram
8
, a plate material transfer control means
32
which controls the plate material transfer means
3
, and a ram axis control means
33
which controls the punch drive means
9
.
The plate material transfer control means
32
controls the plate material transfer means
3
so as to start to transfer the plate material when the punch tool
6
moves up to a pullout height HH2 not contacting with the plate material W after punching the plate material W.
The ram axis control means
33
rotates the servomotor
19
in one direction, the punch tool
6
is controlled so as to reach a height HH1 which is likely to contact with the plate material when the plate material transfer means
3
completes to transfer the plate material and a motor speed pattern VP that is a rotating speed pattern of the servomotor
19
when the punch tool
6
goes up from the non-contact pullout height HH2 to the height HH1 which is likely to contact with the plate material through a top dead center TDC is generated based on a distance D of transferring the plate material, in said pattern the motor speed not being zero when the distance D of transferring the plate material is under the predetermined distance. Additionally in the motor speed pattern VP, it is preferable to come to the set speed in order for the punch tool
6
to punch when the plate material is completed to transfer and the punch tool
6
reaches the height HH1 which is likely to contact with the plate material. The rotational/linear motion conversion mechanism
20
is a crank mechanism and an eccentric cam mechanism, for example.
According to this configuration, the plate material transfer control means
32
and the ram axis control means
33
starts to transfer the plate material W when the punch tool
6
goes up to the pullout height HH2 not contact with the plate material W and the plate material transfer means
3
and the ram axis control means
33
are controlled synchronously such that the punch tool
6
reaches the height HH1 which is likely to contact with the plate material when completing transferring the plate material, so that the unnecessary waiting time is not produced and the hit rate is improved. Moreover, the ram axis control means
33
rotates the servomotor
19
in one direction and the motor speed pattern VP from the non-contact pullout height HH2 to the height HH1 which is likely to contact with the plate material is generated based on the distance D of transferring the plate material, in said pattern the motor speed not being zero when the distance D of transferring the plate material is under the predetermined distance, so that it can be rotated continuously so as not to stop the servomotor
19
. Consequently, the load in accelerating and deaccelerating the speed is low and the accelerating and deaccelerating energy can be low. Thus, high hit rate and energy saving in the punch drive can be realized together.
The above predetermined distance is optional, however it cannot be set directly at distance value and it can be the distance predicted by setting the method of generating the motor speed pattern VP, for example.
Additionally, though the forming part is processed so as to protrude to the upper surface side in general in case of forming with the punch tool
6
, the height HH1 which is likely to contact with the plate material and the non-contact pullout height HH2 are set in the position on the upper surface side of the plate material far from the position in the case of making holes as such a forming part is protruded.
The ram axis control means
33
can make the motor speed pattern VP according to the distance D of transferring the plate material a pattern that the acceleration in accelerating and deaccelerating is constant regardless of the distance D of transferring the plate material.
When the acceleration is constant, the load for calculating the motor speed pattern VP based on the distance D of transferring the plate material can be low by the punch drive means
9
and the high hit rate and energy saving can be realized by the simple control.
The motor speed pattern VP can have the constant speed pattern. When the motor speed pattern VP is made to be a curved line which switches from the deacceleration to the acceleration in V-shaped, the vibration and shock is generated in switching. It is not preferable to generate such vibration and shock when not punching as it is wasteful to generate the vibration etc. When having the constant speed pattern, such a rapid change in speed is not generated, the ram can move up and down smoothly when not punching and it excels at absorbing the vibration and shock.
The plate material transfer/punch motion control program of the present invention is provided for working a computer becoming a means for controlling the punch press as the next plate material transfer control means
32
and the ram axis control means
33
.
The above punch press, making holes and/or forming with the punch tool
6
, comprises the plate material transfer means
3
which transfers the plate material W and the punch drive means
9
which has the rotational/linear motion conversion mechanism
20
which converts the rotation of this servomotor
19
into the rise and fall of the ram
8
and moves the punch tool
6
up and down with the ram
8
by making the servomotor
19
as the driving force.
The plate material transfer control means
32
and the ram axis control means
33
composed by the above plate material transfer/punch motion control program have the means for having the following function.
The above pla

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