• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
  • 法律状态
  • 优先权
    • 专利摘要:
    Method for operating a closing unit (1) of a forming machine, wherein the closing unit (1) is closed and a movable platen (2) is controlled or controlled by a closing force mechanism (3) with a closing force, wherein by means of a movement mechanism (3,4) an offset force directed against the closing force is exerted while the closing force mechanism (3) is active.
    公开号:AT514569A4
    申请号:T651/2013
    申请日:2013-08-21
    公开日:2015-02-15
    发明作者:Herbert Dipl Ing Zeidlhofer；Anton Ing Lohnecker
    申请人:Engel Austria Gmbh；
    IPC主号:
    专利说明:

    1
    The present invention relates to a closing unit of a forming machine having the features of the preamble of claim 1 and a method for operating such a closing unit having the features of the preamble of claim 2.
    Under shaping machines are understood injection molding machines, transfer molding, pressing or the like.
    Modern forming machines have high demands on the dimensional accuracy of the parts produced. This goes so far that the closing force and closing movement profiles, which must be performed by movable mold platens or mold halves mounted thereon, have a great influence on the quality of the product.
    For example, in the case of injection-compression molding, the closing unit of an injection molding machine must be controlled or controlled such that a defined embossing gap is closed in a controlled manner between the mold halves, whereupon the movable mold clamping plate is to experience an increase in the closing force. There are also special forms of this process in which the embossing nip may be reopened more than once before the plastic measures cool.
    The exact Aussteuern or balancing these profiles can then be a problem when in a profile at the same time very small and very large forces exhausts or are required. To stay with the example of injection compression, the closing force mechanism would have to be capable of accurately applying minimum forces as well as forces of several hundred or 1,000 kilonewtons. This can not be done reliably by modern hydraulics in all situations.
    The object of the invention is to provide a closing unit for a forming machine and a method of operating the same, wherein also control of very small closing forces is possible.
    This object is achieved by a clamping unit having the features of claim 1 and by a method having the features of claim 2.
    This is done by exerting by means of a movement mechanism the closing unit an opposing force of the closing force, while the closing force mechanism is active. As the movement mechanism, any of the mechanisms of the closing unit capable of counteracting the closing force mechanism may be used.
    In modern molding processes, particularly in injection-compression molding, it may be intended to open and close the mold halves several times. In this sense, it should be noted that the closing force may also be negative, thereby becoming the opening force.
    Further advantageous embodiments of the invention are defined in the dependent claims.
    Here, "or" is always to be understood inclusive, that is, a combination of "by" or "separate options is of course conceivable and occasionally vorteil.Als movement mechanism, for example, a rapid traverse mechanism for quick opening and closing of the closing unit can be used. As a rule, the rapid traverse mechanism is designed for far lower forces than the closing pressure mechanism. Nevertheless, the rapid traverse mechanism is capable of operating against the closing force mechanism such that the force applied thereto is raised above a minimum force over which the closing force mechanism is finely controllable.
    A hydraulic closing force mechanism may itself be another example of the moving mechanism. For in the event that a closing force mechanism designed as a hydraulic cylinder has a first chamber and a second chamber, wherein the closing force is generated by increasing the pressure in the second chamber, an increase of the pressure in the first chamber can
    Increase the required for the target closing force target pressure in the second chamber cause, whereby the target pressure in the second chamber falls within a finely controllable range.
    Of course, combinations are also possible, that is, for example, one part of the offset force is applied by one rapid traction mechanism and another part by the closing force mechanism itself.
    Thus, the offset force can be applied to the movable platen or the self-pressurizing mechanism itself.
    In order to convey the closing force mechanism as far as possible into a region in which it can be finely controlled or regulated, it can be provided that substantially the maximum permissible force for the movement mechanism is exerted as an offset force. This is especially provided when a target closing force is comparatively small, so that the control of the closing force mechanism is difficult. At high closing forces, it may be intended to reduce the offset force.
    It may be provided that a closing force absolute value substantially corresponding to an actual force acting on the movable platen, and the closing force absolute value being used as the feedback amount of the control, are determined for controlling the closing force. Hereby, the establishment of manufacturing processes can be simplified because of a movement or force profile in absolute values can be determined in advance by calculation or simulations and then realistically mapped by the clamping unit.
    In this case, it may be advantageous, not only the closing force applied by the closing force mechanism or the offset force applied by the moving mechanism, but also a support force caused by the mass or at least one frictional force of at least one beam, the movable mold clamping plate or the movable mold clamping plate together with a
    Measure mold half and take into account the measured forces in the determination of the closing force absolute value.
    In order to compensate for the influence of the weight, for example a mold half, in vertical clamping units, it may be provided that the assisting force is measured by maintaining the at least one bar or movable mold clamping plate at a constant height together with a mold half from the movement mechanism of the clamping unit and the force exerted therefrom by the moving mechanism is measured.
    It can be provided that the support force is determined by means of a pressure sensor or a plurality of pressure sensors in at least one hydraulic cylinder of the movement mechanism.
    In this regard, in a particularly preferred embodiment, it may be provided that the assist force is determined by a first pressure sensor in a first chamber of the at least one hydraulic cylinder and a second pressure sensor in a second chamber of the at least one hydraulic cylinder, the counterforce value being calculated from a difference of the effective piston area Measured values of the first pressure sensor and the second pressure sensor is determined. It is true that in most operating conditions the pressure in one of the chambers is much lower than in the other. However, by the present invention, the control or regulation can be performed so precisely that even this small effect can produce a relevant falsification.
    In a preferred embodiment it can be provided that the least of a frictional force is measured in the form of an adhesive force of the at least one spar or the movable platen.
    This can be done by measuring a weight force of the at least one spar or the movable platen for measuring the adhesive force, that the at least one spar or the movable platen from
    Movement mechanism of the clamping unit is kept at a constant level, that a counterforce exerted by the movement mechanism is measured and that the adhesion force from the difference of the amounts of the counterforce and the weight force is determined. The weight of the spars or of the movable mold clamping plate can advantageously be measured before assembly of the closing unit, for example with a crane scale. The counteracting force exerted by the moving mechanism can be measured as previously described in the supporting force, except that in this case no mold half is mounted on the movable platen. In general, this embodiment is based on the assumption that the presence of a mold half will increase the adhesive force between the movable mold plat and spars , or between bars and guides occur, are only slightly affected. Of course, it is also possible to metrologically detect the influence of the weight of the mold half on the adhesive force. For this purpose, the weight of the mold half must be known or measured.
    Another particularly preferred embodiment may be that the at least one frictional force is measured in the form of a sliding friction force of the at least one spar or the movable platen.
    Again, the weight of the at least one spar or movable platen can be advantageously measured prior to assembly of the closure unit. Likewise, the motive force can be measured in a similar manner as suggested for the counterforce. The effect of the weight of a mold half unfolds similarly as described with respect to the adhesive force.
    At least three different methods have been described for determining forces that distort the absolute closing force. These can each be singled and used in combination. It can be decided by the skilled worker in which situation (process characteristics, vertical or horizontal clamping unit) which method makes sense or which distorting force exerts a relatively large influence.
    Regardless of the precise operation of the control, the invention is based on the recognition that it is possible by means of moving mechanisms provided on the closing unit to keep the force to be applied by the closing force mechanism in a range in which the closing force mechanism is well controllable.
    Further advantages and details of the invention will become apparent from the figure and the associated description of the figures. Showing:
    Fig. 1 is a schematic side view of a closing unit a
    Injection molding machine, wherein an embossing gap exists between the mold halves,
    2 is a representation corresponding to Figure 1, wherein the closing unit is fully closed,
    Fig. 3 is a schematic side view of a closing unit in a position which allows the measurement of the assisting force, and Figs. 4 is a schematic representation of a control concept according to a method of the invention.
    In Figure 1, a vertical clamping unit 1 is shown purely schematically. It has a pressure mechanism 3, which can cause a loading of the movable platen 2 with a closing force via bars 6. For locking the movable platen 2 with the spars 6, a locking mechanism 13 is provided. In the unlocked state, movement of the movable platen 2 by means of the rapid traverse mechanism 4 is possible.
    The control of the pressure mechanism 3 and the speed mechanism 4 is performed by a controller 5. The illustrated connections between rapid traction mechanism, control or regulating device and closing force mechanism are of course of a purely schematic nature.
    Both the pressure mechanism 3 and the rapid traverse mechanism 4 have hydraulic cylinders 8.
    The structure of the hydraulic cylinders in this embodiment is analogous to both the speed gear mechanism 4 and the pressure mechanism 3. The hydraulic cylinders 8 only differ depending on the requirement profile in their stroke and in their effective piston area.
    The hydraulic cylinders 8 each have a first chamber 10 and a second, rod-side chamber 12, which can each be acted upon with different pressures. The hydraulic circuit of the cylinder is prior art and therefore not shown in detail. Disposed on the first chamber 10 and on the second chamber 12 of each hydraulic cylinder 8 are a first pressure sensor 9 and a second pressure sensor 11, respectively, for measuring the hydraulic pressure in the respective chamber. Also, the first pressure sensors 9 and the second pressure sensors 11 are connected to the control device 5. This is not shown for clarity. In the case where the control or regulating device 5 is designed as a control device, the first pressure sensors 9 and the second pressure sensors 11 serve to return measured values for the control loop.
    In the situation illustrated in FIG. 1, an embossing gap exists between the mold half 7 and the further mold half 14. By acting on the rapid traction mechanism 4 with a maximum allowable force against the closing force mechanism 3, a minimum pressure is given in the second chambers 12 of the hydraulic cylinders 8 of the closing force mechanism 3. This is necessary for a precise regulation.
    FIG. 2 is analogous to FIG. 1, the embossing gap now being closed. Furthermore, the rapid traction mechanism 4 counteracts the closing force mechanism. This happens until a target closing force is so great that in the second
    Chambers 12 of the hydraulic cylinder 8 of the closing force mechanism 3 present pressure is large enough to ensure a precise control or regulation.
    In the situation shown in Fig. 3, the assisting force (assisting the closing force) exerted by the beams 6 of the movable mold mounting plate 2 and the mold half 7 in the molding process is measured by the rapid traverse mechanism 4 and the printing mechanism 3 separately from each other. For this purpose, the locking mechanism 13 is unlocked. By the sensors in the hydraulic cylinders 8 of the rapid traverse mechanism 4, a part of the assist force originating from the movable die plate 2 and the die half 7 is measured. A second part originating from the arms 6 is measured by the sensors in the hydraulic cylinders 8 of the pressure mechanism 3. The support force is then determined as the sum of the first and second sub-forces.
    The force measurement by the sensors in the hydraulic cylinders 8 will be described below: The effective area in the second chambers 12 is slightly less than the effective area in the first chambers 10. The magnitude of the measured sub-forces of the assist force will therefore be a difference of the amounts weighted by the effective area the hydraulic pressures measured by the first pressure sensors 9 and the second pressure sensors 11.
    In the embodiments shown here, any force measured by the pressure sensors in the hydraulic cylinders 8 is performed in the described manner. However, this is not absolutely necessary because, for example, the pressure from those chambers, which have the respective lower pressure, can be completely drained, whereby only the pressure in the respective other chamber contributes to the force application of the hydraulic cylinder 8.
    If the weight forces of the movable platen 2 and the spars 6 are known (for example, by measuring by means of a crane scale before the assembly of the clamping unit), with a similar procedure, as described above, and the adhesive force of the movable platen
    Spars 6 are measured. This adhesive force is mainly caused by the guides of the movable platen 2 and the spars 6 and the static frictional force occurring in the hydraulic cylinders. A counterforce is measured analogously to the support force, with the mold half 7 having to be dismantled or dismounted. The adhesive force can then be determined quite simply from the difference between the amounts of the counterforce and the weight force.
    By the method according to the invention it is possible to carry out a regulation or control of the absolute value of the closing force. A corresponding control concept is shown in FIG. In this case, a balance of forces is first set up from the amounts of the following forces acting on the platen: The first rapid traction FE1, which is determined by means of the first pressure sensors 9 in the first chambers 10 of the hydraulic cylinders 8 of the rapid traction mechanism 4. The first pressing force FD1, which is determined by means of the first pressure sensors 9 in the first chambers 10 of the hydraulic cylinders 8 of the closing force mechanism 3. The second rapid traction FE2, which is determined by means of the second pressure sensors 11 in the second chambers 12 of the hydraulic cylinders 8 of the rapid traction mechanism 4. The second pressing force FD2 determined by the second pressure sensors 11 in the second chambers 12 of the hydraulic cylinders 8 of the closing force mechanism 3. - The weight force FB of the movable platen 2 together with the mold half 7, which is determined by means of the pressure sensors of the rapid traverse mechanism 4. - The weight FH of the spars 6, which is determined by means of the pressure sensors of the closing force mechanism 3. The frictional force FR, using, depending on the situation, sliding friction or sticking friction.
    The closing force actual value FS-IST appearing as a result of the balance of forces is compared with a closing force target value FS-SOLL specified by the operator. The result of this comparison is in turn fed to the control device 5 - in this case as a control device. This influences an actuator 15, which in the above embodiment is a control valve for the hydraulic pressure in the second chambers 12 of the hydraulic cylinders 8 of the closing force mechanism 3.
    Of course, the pressures in the remaining chambers of the hydraulic cylinders 8 are subject to similar control mechanisms. In particular, the control for the first rapid traction force FE1 and the first urging force FD1 are such that at least one of these two forces is increased should the pressure in the second chambers 12 of the hydraulic cylinders 8 of the closing force mechanism 3 fall below a certain threshold, below which a precise control of the second Compressive force FD2 is difficult.
    The presented control concept allows the regulation of an absolute closing force. This has the advantage that results from simulations or calculations can be used directly to set up the process. Test series for optimizing the closing pressure profile may thereby be completely avoided.
    The present invention is not limited to the embodiments illustrated herein. For example, the invention can also be applied to horizontal closure units. Likewise, it is also possible to apply the invention to electromechanical clamping units, as these too may suffer from impaired controllability of closing forces.
    权利要求:
    Claims (15)
    [1]
    Claims 1. A clamping unit of a forming machine comprising a movable mold clamping plate (2), a closing force mechanism (3) for urging the movable mold clamping plate (2) with a closing force, a moving mechanism (3,4) for moving the movable mold mounting plate (2) and a control device (5) for controlling the closing force mechanism (3) and the moving mechanism (3, 4), characterized in that the control means (5) is arranged to control or control the moving mechanism (3, 4) exerts an offset force opposing the closing force while the closing force mechanism (3) is activated.
    [2]
    Method for operating a closing unit (1) of a shaping machine, wherein the closing unit (1) is closed and a movable mold clamping plate (2) is controlled or controlled by a closing force mechanism (3), characterized in that by means of a moving mechanism (3, 4) an offset force is applied against the closure force while the closure force mechanism (3) is active.
    [3]
    A method according to claim 2, characterized in that a quick-action mechanism (4) is used as the movement mechanism (3, 4).
    [4]
    Method according to claim 2 or 3, characterized in that the closing force mechanism (3) is used as the movement mechanism (3, 4).
    [5]
    5. The method according to any one of claims 2 to 4, characterized in that as an offset force substantially for the movement mechanism (3,4) maximum permissible force is applied.
    [6]
    A method according to any one of claims 2 to 5, characterized in that for controlling the closing force, a closing force absolute value substantially corresponding to an actual force acting on the movable platen (2) is determined, and the closing force absolute value is used as the feedback amount of the control.
    [7]
    Method according to claim 6, characterized in that a closing force applied by the closing force mechanism (3) is measured, that the offset force applied by the moving mechanism (3,4) is measured and that the measured forces are taken into account in the determination of the closing force absolute value.
    [8]
    A method according to claim 7, characterized in that an assisting force or at least a frictional force of at least one stile (6), the movable platen (2) or the movable platen (2) caused by the mass is measured together with a mold half (7), and that measured forces are taken into account in the determination of the closing force absolute value.
    [9]
    A method according to claim 8 using a vertically closing closure unit (1), characterized in that the supporting force is measured by the at least one bar (6) or the movable mold mounting plate (2) being moved together with a mold half (7) from the moving mechanism (3, 4). is held at a constant level and the force applied thereto by the moving mechanism (3,4) is measured.
    [10]
    A method according to claim 9, characterized in that the support force is determined by means of one or more pressure sensors (9, 11) in at least one hydraulic cylinder (8) of the movement mechanism (3, 4).
    [11]
    A method according to claim 10, characterized in that the support force is generated in a first chamber (10) of the at least one hydraulic cylinder (8) and a second pressure sensor (11) in a second chamber (12) of the at least one hydraulic cylinder (8 ), wherein the value for the counterforce is determined from a difference of the measured values of the first pressure sensor (9) and of the second pressure sensor (11) which is weighted by effective piston areas.
    [12]
    A method according to any one of claims 8 to 11, characterized in that the at least one frictional force is measured in the form of an adhesive force of the at least one beam (6) or the movable platen (2).
    [13]
    Method according to claim 12, using a vertically closing closure unit (1), characterized in that, for measuring the adhesion force, a weight force of the at least one spar (6) or movable mold mounting plate (2) is measured, the at least one spar (6) or the movable platen (2) is kept at a constant height by the moving mechanism (3,4), that an opposing force applied therefrom by the moving mechanism (3,4) is measured, and that the adhesive force is determined from the difference of the amounts of the counterforce and the weight.
    [14]
    A method according to any one of claims 8 to 13, characterized in that the at least one frictional force is measured in the form of a sliding friction force of the at least one spar (6) or the movable platen (2).
    [15]
    Method according to claim 14, using a vertically closing closure unit (1), characterized in that, for determining the frictional friction force, a weight force of the at least one stile (6) or movable platen (2) is measured comprising at least one spar (6) or the movable one Platen (2) is moved at a constant speed by means of a moving mechanism (3,4), a motive force applied thereto by the moving mechanism (3,4) is measured, and the sliding frictional force is determined from the difference of the weights and the motive force.
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    同族专利:
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    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    JP2009061627A|2007-09-05|2009-03-26|Toshiba Mach Co Ltd|Clamping device|
    NL9500238A|1995-02-09|1996-09-02|Fico Bv|Casing device with compensation element.|
    IT1312425B1|1999-06-30|2002-04-17|Wintech S R L|PRESS WITH MOLD HOLDER EQUIPMENT|
    DE102005053802A1|2005-11-11|2007-05-16|Demag Ergotech Gmbh|Closing device for an injection molding machine|
    AT12819U1|2011-01-19|2012-12-15|Engel Austria Gmbh|VERTICAL TWO-PLATE CLOSE UNIT|JP6820178B2|2016-10-07|2021-01-27|東洋機械金属株式会社|Molding machine|
    AT519253B1|2016-12-15|2018-05-15|Engel Austria Gmbh|Control unit for a molding machine|
    法律状态:
    优先权:
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    ATA651/2013A|AT514569B1|2013-08-21|2013-08-21|Method for operating a closing unit|ATA651/2013A| AT514569B1|2013-08-21|2013-08-21|Method for operating a closing unit|
    DE201410012023| DE102014012023A1|2013-08-21|2014-08-13|Method for operating a closing unit|
    CN201410642420.XA| CN104512016B|2013-08-21|2014-08-21|A die assembly unit of a forming machine and a method for operating a die assembly unit|
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