FR2501549A3 - METHOD OF HOT FORGING CONTROLLED BY A PROCESS CALCULATOR - Google Patents

Abstract

HOT FORGING PROCESS FOR INGOTS PUT IN FORGING POSITIONS BY MEANS OF A MANIPULATOR ON A FORGING PRESS CONTROLLED BY A PROCESS COMPUTER, THE FORGING PLAN BEING CALCULATED AND SUPPLIED TO THE PRESS CONTROL SYSTEM THROUGH THE INTERMEDIATE OF THE PROCESS CALCULATOR. DURING FORGEING, THE MAXIMUM PERMISSIBLE DEFORMATION OF THE PART IS SET ON THE PROCESS COMPUTER BEFORE THE START OF FORGING, DATA RELATING TO THE COMPOSITION OF THE MATERIAL AND TO THE DIMENSIONS OF THE TOOLS AND THE PART ARE SET ON THE PROCESS CALCULATOR AND FORGING. AT LEAST EACH TIME ONE PASSAGE OF THE FORGED PRODUCT, THE PROCESS COMPUTER DETERMINES CONTROL VALUES TO BE PROVIDED FOR THE CONTROL OF THE FORGING PRESS.

Description

The present invention relates to a hot forging process, or

  stamping, set into forging positions by means of a manipulator on a forging press controlled by a process calculator, the forging plane being calculated and supplied to the press control system through

of the process calculator.

  For processes of this type, it is conventional, particularly

  firing data relating to the temperature, the dimension of the ingot, the final dimension and the part, to establish by means of a calculator forging plans that the driver of the forging press can call at his choice. To have an extensive forging program, you need a very large number

  such plans and in addition a calculator not

  part of the program control system and an appropriate memory

  requested from the control system of the forging press. With those

  plans, we can achieve a programmed forging, which allows

  significantly reduces forging time. However, this only applies if the deformation rates

  classified forging plans correspond to at least

  approximately to the maximum possible values.

  However, because of the different heating of the ingots and the differences in material from one filler to the next, even for ingots of the same size and same material, there are significant dispersions of the allowable deformation rate.

  and forging forces. For the driver of the

  These differences can be taken into account

  see, in the choice of forging program, he must, including

  taken for pieces of the same initial dimensions, same final dimensions and same material, to have several planes of forging with different rates of deformation,

  so that a forging press with a manufacturing program will

  already requires several hundred forging plans and must register them. The expense required for this being

  important, it has not been possible to go into the practice of forging

  only for forging installations

limited production.

  From there, the invention aims to give a high utilization factor to forging presses, including

  those who have a very differentiated manufacturing program.

  It should be considered for this reason that the performance of a forging installation depends not only on the technical values of the forging but also on the dynamic behavior of the press and the manipulator, the acceleration power and the speed of the manipulator, in the first place. limiting

the use of the press.

  The invention achieves this goal by virtue of the fact that during forging, the maximum permissible deformation of the piece is

  set on the process calculator according to

  discernable and continuously determined

  that appear on the part, - that before the start of the forging, the data relating to the composition of the material and to the dimensions of the tools and the workpiece are set on the process calculator,

  - and that for at least

  forged dude, the process calculator determines values

  of control to be provided-for the control of the forging press.

  It is thus possible to determine the data for each passage of the product to be forged, the provision of the maximum permissible deformation of the material ensuring the full utilization of the deformation capacity of the part. For the fixation of the maximum possible deformation of the material, which includes the adjustment of the maximum permissible rate of deformation and the pitch

  of displacement, or bite> optimal, we use mainly

  the values of the compressive forces, the increase of the compressive force and the forming temperature.

  measured during deformation. In addition,

  detection of optoelectronic recognition means, such as diode line cameras in the arrangement

  DE-OS 25 16 756 or devices sweeping the surface (Proc.

  Conf. on Steel Rolling, Tokyo 1980, page 87) associated with

  learning circuits, for example according to DE-OS 28 26 313.

  The comments of the press driver are also taken into account as guidance and correction. Observations are made with respect to characteristics that are considered criteria for assessing the deformation of the

  material, that is to say as a rule of deformation rate.

  Thus, for example, on the outside of the ingot, the cross of

  The gage is observable as the lower limit of effective deformation. In addition, there are clear signs of the approach of the upper limit of the deformation rate, for example the appearance of cracks still catching up or the appearance of rhombic deformations of the product section.

  wrought. Deformation is also characterized by noises

  coming from the room that can be distinguished audio-electro

  nically and also by the driver. In addition, for the maximum possible deformation, the preheating time and the position of the product can be taken into account.

  in the oven. By constantly adapting criteria, in parti-

  the maximum permissible rate of deformation and the maximum possible displacement rate, the deformation behavior of the workpiece according to the measurement results

  indicated, we intervene permanently in the action of

  process and this can determine the best possible run values for the next pass and provide them for the control of the forging pass. There is no waste of time, because we have a time of

  sufficient calculation during a passage.

  The data to be adjusted only once on the process calculator are essentially those concerning the

  material composition, initial dimensions and di-

  final dimensions of the workpiece and the dimensions of the tools.

  From the dimensions of the tools and the part and the values

  their measured forging force, can be deter-

  the resistance to deformation, ie the deformation force related to the active surface of the die, and

  the resistance to deformation of the forged product.

  Forged steel ingots, for which the

  method of the invention is in particular provided, it can be

  the fact that the resistance to deformation, for

  even very different material positions, decreases as the temperature increases. On the other hand, the deformability of the material increases with temperature. It is thus possible, with the deformation resistance determined from the measured forging force, to determine the maximum permissible rate.

250 1549

  deformation. Other magnitudes of influence taken in con-

  sideration in the fixation of the admissible rate of deformation are the relative variation of the resistance to deformation

  during forming and forming temperature.

  In forging-drawing, product enlargement

  forged essentially depends on the form of the

  port of the bite width to product width and resistance to deformation. Enlargement, relatively to the calculation of data for the control of the forging press, is one of the most important quantities because it is only calculable in advance and gives at the end of

  account, when is provided the maximum allowable rate of

  training, the forging dimension at which tools can

to be close together.

  In fixing the bite width or the movement pitch of the manipulator to be adjusted, it is necessary to observe the

  the following known condition: the ratio of the width of

  The height of the forged product must be greater than 0.3 to 0.4 in order for the core forging to be sufficient, but must not exceed 0.1 for the enlargement to be too large. These relationships are familiar to those skilled in the art

  (Stahl und Eisen, 1971, pp. 864-876).

  The invention is illustrated by the appended schematic drawings, in which:

  FIG. 1 is a race-time diagram of the function

  the press and the manipulator; FIG. 2A shows the variation of the resistance to deformation and the deformability of the part as a function of the temperature; FIG. 2B shows the variation of the resistance to deformation during forming; FIGS. 3A and 3B show calculated and measured expansion coefficients; FIG. 4 shows the calculation scheme used for the process calculator and

  FIG. 5 is a diagrammatic representation of the

transferred from the invention.

  Figure 1 shows the combination of movements to

  order from the forging press and the manipulator. In particular, it shows that lost time can be avoided if the

  period of movement of the manipulator falls most accurately

  possible in the period of the return run of the press. We first observe along the run of the press

  maneuvering points which, according to the position of the

  lead to maneuvers that control the training

  the press. However, we see a maneuver point 9 located in the return race that triggers the start of the

  manipulator. The manipulator then executes a step of

  which fixes the width of the bite. Schematically shown in the right part of the drawing part of a room on which is a stamp 16. The notions of forging dimension and depth of penetration are highlighted here. We also see that the bite width 19

  is smaller than the width of the stamp.

  FIG. 2A shows the decrease of the resistance to deformation and the increase of the deformability with the temperature for a steel in the temperature range

usual forging.

  FIG. 2B shows very different growths of the resistance to deformation for different forming conditions (I, II) during the penetration of the stamps into

the forged ingot.

  Figure 3 shows the good reliability of the enlargement coefficients determined by the calculation; in Figures 3A and 3B are compiled calculated values and values

  measured. The enlargement coefficient, logarithm ratio

  from the deformation in width to the logarithm of deformation

  height, is plotted against different values of the ratio of the bite width to the width of the forged product (S / B). In Figure 3A is additionally considered

  the ratio of the width to the height of the forged product.

  The block diagram of Figure 4 gives the calculation scheme. In the "Input" block are entered the data relating to the initial dimensions of the part, the final dimensions and the dimensions of the tools to be established only at the beginning of the forging as well as the values measured during the forging of the forging force and the temperature of forming.

  Figure 5 shows the position of the

  in the process of the invention. The driver of the forging press therefore first has to make the following entries or adjustments: - entry by keyboard of the final forging dimension, - entry of the dimensions of the ingot by placing the stamp and transfer by keyboard of the height ingot determined

  by the digital measuring system of the press.

  After each pass, there is a need for step indexing.

  is. The measurement data of the forging force and the

  forming temperature as well as light barrier

  for fixing the direction of movement are introduced continuously. The rate of deformation as well as the displacement pitch and the direction of movement of the manipulator can

  to be regulated automatically or as

  than correction. The process computer provides according to FIG. 5 the data necessary for the movements to be controlled of the press and the manipulator according to FIG. 1, namely the forging dimension, the displacement pitch, the stroke

  back and unblocking the manipulator.

  Using the calculation scheme shown in FIG.

  re 4, there is, with a small need for memory locations, short computation times. The necessary control values can thus be calculated for each subsequent pass without

waste of time.

Claims (7)

claims   1.- Hot forging process of ingots placed in position   forging using a manipulator on a forging press controlled by a process computer, the forging plane being calculated and supplied to the control system of the   press through the process calculator, which is   the fact that during forging, the maximum allowable deformation of the workpiece is set on the process computer according to discernible and continuously determined forming characteristics which appear on the workpiece, - that before the beginning of forging, material composition data and tool and workpiece dimensions are set on the process computer - and that for at least one pass of the forged product, the process calculator determines   command to be provided for the control of the forging press.   2. Process according to claim 1, characterized by   the fact that the maximum permissible rate of deformation is during the forging.   3. A process according to one of claims 1 and 2, characterized   the fact that the optimal pace of movement of   Pulverizer is provided in addition to your choice.   4. Method according to one of claims 1 to 3, characterized   characterized by the fact that the process calculator provides, for the forging, the forging dimension, the displacement pitch,   the return stroke and the release of the manipulator.   5. A process according to claim 4, characterized in that a signal characterizing the direction of movement of the   manipulator is set on the process calculator.   6. A process according to one of claims 1 to 5, characterized   terized by the fact that password indexing is triggered after each passage.   7. A process according to one of claims 1 to 6, characterized   characterized by the fact that the forging force, the forming temperature, the shape of the forged product and the state of its surface are measured as discernable forming characteristics and that these characteristics are sent as signals   input to the process calculator during forging.   uoTssaidwoD op essnoD: E Ue ean4e adwea: Z 9; alTqewjoj9a: * Z the úZ uoT; ewio; 9p VI w aDsTsau:, zz a zz: gz eV y- sbTd ineaetndTuew np esanoD: úE esseid el ap asJnoD: E sdwea: Zt 3HDHYW Jna; elndTuew: Ol uaweovldd p op sed: tl j, 3IUV inelQIndTueW: t; 4uewaDeldgp ap eaina: a6ea6bo; p eaoD: LI 3HDHVW ino4ae - j3W V uolssaidwoD: = uoT4eilaud ap inepuojoid: 8L esinoD ep aJna: IZ inolea ap asanoD: 3HDHVW uoTssaedwoD - 3HUy eauaDsea: 9 3HDVW ea; uaesaa - 13U1V JnoleU: S s3unsDI S3 'un 3DN3U3d3U 3S S3UJZIHD S3a NOLVDIJINDIS 6tSLOSZ Figs. 3A and 3B 27: Bite Width / Forged Product Width S / B 26: Width Coefficient 1 24: Calculation: Measure 28: Width / Height b) Calculation Measure3) 1 / h Fiq. 4: -   29: Input: Calculation of displacement pitch, deformation resistance and strain rate 31: Calculation of width, height and length of forged product 32: Control of restrictions: Modification of height reduction or of the displacement step 33: Calculation of the return stroke of the press and the release of the manipulator 34: Temporal optimization 36: No rotation 0/90 37: Next pass 38: Optimization of the reductions of height of the last passes (passes of dressing and smoothing) Fig. 5: 42: Temperature 43: Initial dimension 44: Transfer 41 ': Direction of movement: Final dimension 46: Part group 47: Pass + 1: Deformation rate i1l: No displacement 41: Direction of movement 39: Process calculator 48: Calculation of the displacement pitch, the deformation resistance and the strain rate 49: Calculation of the forging plane 17: Forging dimension 2: Return stroke: Release of the manipulator