FR2775207A1 - PROCESS AND DEVICE FOR AUTOMATICALLY ELIMINATING THE ANTERIOR AND POSTERIOR ENDS OF MATERIAL BARS WORKED IN SHAPING PRESSES - Google Patents

Abstract

The invention relates to a method for automatically removing ends of bars of material in forming presses. To reliably remove bar sections with glued end sections, the front end section and the rear end section of each material bar between the cutting stage and the first forming stage are removed and at least the bar section which follows the front end section is shaped as far as the last forming stage, then it is discarded.

Description

Method and device for automatically eliminating ends

  anterior and posterior material bars

  worked in shaping presses.

  The present invention relates to a method for eliminating self-

  matically the anterior and posterior ends of material bars

  riau of finite length worked in forming presses, which bars, in a first step, are moved in a continuous manner following a rectilinear transport nozzle, then are brought by intermittent advance against a stop of a cutting-off tool in the area of which at least the anterior end and the posterior end of each bar of

  material are eliminated, the position of a bar end or a chan-

  helm position in the sectioning area being calculated using a microprocessor and the microprocessor determining, taking into account the position of the end of the helm or the change of helm, if necessary eliminate one length or two lengths of bar sections and the

  elimination process being controlled by the microprocessor.

  Automatic horizontal presses which shape up to several hundred pieces per minute, without chip formation, from bar materials, are continuously fed with bars

  of material which in many cases are preheated before

  swim. Just before shaping, the bars are cut into bar sections of the same length which must meet volume tolerances

  relatively tight. To guarantee the necessary volume of each section

  bar lesson, we eliminate the bar start and end sections.

  In a known method for cutting by cutting bars

  res in elementary bar sections of determined length, eliminating

  at least the start and end sections of the bars, in which

  probes and meter systems are used for automatic

  saion of the cornmmande, the bars to be cut are moved one after the other with a constant speed of advance, while the first bar is transported intermittently with a speed

  which is greater than the feed speed and which, at the end of the intermit-

  tries the first bar, advanced the same bar by the same amount

  tance that previously the constant constant speed of advance, is better

  born against a stop and the planned length is cut off at the end of the bar, a sensor located at a distance from the stop which corresponds to a multiple of the length to be cut off, when passing a bar end, triggering a counter which controls a device associated with

  the cutting-off tool which either routes the elementary bar sections

  res to the next forming stage, or withdraws them from the shaping cylce, so that the number (n) previously set of bar sections

  be transmitted to the next forming stage, but the name

  bre of elementary bar sections obtained at the end of the bar and at the beginning of the next bar by a number (x) of operations planned

  cutting is eliminated (document AT-PS 263 502).

  To avoid having to calculate new values each time

  Fication, for example when changing the length of the section, and to take these into account by new settings, another method has been developed to automatically eliminate the anterior and posterior ends of bars of material of finished length . According to this method, the length of a transport zone (a) which follows the continuous drive zone in the transport direction of the bars of material, at least a distance (b) between the rear end of this zone (a) in the direction of

  transport and a plan which defines the area of action of the inter-

  mittent on a bar and at least one of the distances (d or d + P) between the end of the mentioned area and a cutting plane (SE) or a stop plane (AE) are stored as reference data in a microprocessor, the entry and exit of each bar end in or out of zone (a) as well as the time of transport from the bar end to

  inside this area are detected and recorded by the microprocessor

  sor and, from this latter data, reference data and data corresponding to the length of the desired sections of material, the microprocessor calculates the position of a bar end or a bar change in the sectioning area and , taking into account the position of the bar end or the bar change, determines whether

  one or two lengths must be eliminated and ordered accordingly

  the process of removing bar ends

(DE-PS 29 40 375);

  This process is applied as standard on all horizontal presses.

  zontales. The position of the transition between two bars of material

  Cutting is determined before forming by a clean probing system and processing electronics and is recalculated with each new feeding stroke of the machine. Thus the instant when the end of the bar arrives in the cutting stage located just before the first forming stage is

  known. For various reasons it is not desirable to use the par-

  end ties. The main reason is that in a material bar it is normally not possible to make an integer multiple of rough bar sections. This is why we always cut off at the ends of the

  bars in contact two sections of bar (falls) which two have a long

  which corresponds to the length of a complete section. The command

  transmits an order not to support the two end sections

  mite for transport between the cutting stage and the first stage of

forming.

  A large part of the forged products require that we use

  a closed matrix from the first forming stage. Normally the section

  complete bar lesson is brought to the entrance of the first forming stage by the transverse transport means, is pushed by the punch into the

  open matrix and is shaped by closing the matrix.

  Often we get a section at the bar change

  long end and a short end section. The known process does not

  does not guarantee the systematic fall of the short section. Observations

  carried out over relatively long periods and on defective stamped parts returned show that the end sections

  short (called "washers" in the following) when switching to the next bar

  can enter the first stage of open forming, stay there

  and be shaped at the same time as the following complete bar section.

  This is partly due to the dynamics of the accelerating and relatively light washer, which does not always fall with the longer and heavier end section, but "flies" uncontrollably into the

matrix chamber.

  In other situations, a washer gets stuck in the cutting space between the movable blade in the transverse transport means and the fixed counter blade. As the larger end section falls, the jammed washer is brought to the entrance of the first forming stage, is detached from the transverse transport means and is pushed back into the

die by the press piston.

  Countermeasures commonly implemented in practice

  that, such as ejection rods in the blade or sweeping the blade and the die with compressed air, are not effective in all cases. In multi-stage presses, the elastic deformation of the press varies depending on the load, when the load decreases, that is to say when the discarded end sections are removed, and when returning to load of the forming stages. In some forged products

  then parts appear with excessive deformation or

  bias deformed ties which do not offer the required quality. The last

  section before bar change and the first section after bar change

  bar gage are more particularly concerned. To avoid this phenomenon

  nomene we eliminate in addition, by a suitable adjustment of the electronics, the complete section which precedes and the complete section which follows the change

helm.

  The object of the present invention is to improve the methods

  known so that the sections of material to which a washer remains attached

  can be disposed of safely and do not reach the milestones

  subsequent manufacturing in other machines where they could

  improve tools or feeding systems or even fail

  at the customer's premises where they could cause operating problems

considerable.

  This object is achieved according to the invention by the fact that it eliminates

  the anterior end and the posterior end of each bar of material

  riau in known manner, between the cutting stage and the first forming stage and which are shaped to the last forming stage at least the

  bar section which follows the anterior end of the material bar

riau and then we eliminate it.

  Advantageously, at least the preceding bar section of material is also shaped up to the last forming stage.

  the posterior end of the material bar and then removed.

  In accordance with an embodiment of the invention, use is made of

  the signal for elimination of the anterior end and the posterior end

  of each material bar as an input signal for the com

  order of a sorting flap placed after the last forming stage, for

  mine the contiguous sections at the anterior and posterior ends of

each material bar.

  In a device for implementing the method according to the invention, a discharge hopper for good stamped parts and discarded stamped parts comprises a sorting flap by which the coins

  scraps are separated from good parts.

  Thus, the end falls of the bars linked to the neighboring bar sections are eliminated in a safe manner and cannot cause deterioration during the consecutive manufacturing operations or

  cause problems during their use at the customer.

  The invention will be described below in detail with reference to the drawings. These show Figure 1 in Figure 3, schematically, the course of the known process and Figure 4 in Figure 5, schematically, the process according to the invention. Figure 1 shows the material supply conditions of a forming press. Shown in simplified form, the forming press comprises the feed rollers 1, a stop 2, the cutting tool 4 linked to a transverse conveyor 3 as well as the forming stages. Between the feed rollers 1 passes a bar of material 5 which is cut into elementary bar sections 6. At the end of the bar

  of material 5, there remains a rear end section 7, the length of which

  length is less than the length of the elementary bar sections 6 which must undergo additional forming. The next material bar 8 is brought against the material bar 5. It exhibits after shearing

  an anterior end section 9 (washer) which is also sensitive-

  shorter than a bar section 6.

  In known machines or methods, a command not shown (microprocessor) issues an order not to support the two end sections 7 and 9 between the cutting stage 10 and the first forming stage 11 as is see in Figure 2. Usually, for safety reasons, an additional bar section 6 'and 6 "is eliminated before and after the bar change, that is to say after the end sections 7 and 9 , which like the

  shown in Figure 3, fall into the hopper 12.

  The process according to the invention appears in FIG. 4. The sections

  end sections 7 and 9 of the material bars 5, 8 are eliminated as in the known process between the cutting stage 10 and the first stage

  forming 11, while the neighboring bar sections 6 'and 6 "are so-

  born up to the last forming stage 13 and are eliminated in the hopper at

  rejects only at this level by a flap 14 controlled by the microprocessor

  sor not shown (see Figure 5).

Claims (4)

  1. Method for automatically eliminating the anterior and posterior ends of bars of material of finished length worked in forming presses, which bars, in a first step, are moved in a continuous manner following a rectilinear conveyor belt, then are brought in advance intermittent against a stop of a cutting-off tool in the area of which at least the end   anterior and posterior end of each bar of material are eli-   mined, the position of a bar end or a bar change in the cutting area being calculated using a microprocessor and the microprocessor determining, taking into account the position of the bar end or bar change, if it is necessary to eliminate a length or two lengths of bar sections and the elimination process being controlled by the microprocessor, characterized by   eliminates the anterior end and the posterior end of each   that bar of material in known manner, between the cutting stage and the first forming stage and that at least the bar section which comes after the end is shaped up to the last forming stage   front of the material bar and then removed.   2. Method for automatically eliminating the anterior and posterior ends of bars of material according to claim 1, characterized in that one also shapes until the last stage of forming at least the section of bar of material which precedes the end   back of the material bar and then remove it.   3. Method for automatically eliminating the anterior and posterior ends of bars of material according to claim 1 or   2, characterized by the fact that the elimination signal of the external   anterior and posterior end of each bar of material as an input signal for controlling a sorting flap placed after the   last forming stage to eliminate the sections contiguous to the extremi   anterior and posterior tees of each bar of material.   4. Device for implementing the method according to a   any one of claims 1 to 3 comprising a discharge hopper   for good parts and discarded parts, characterized in that a sorting flap (14) is arranged in the discharge hopper (12) for good parts.