Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C45/00—Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor
  • B29C45/17—Component parts, details or accessories; Auxiliary operations
  • B29C45/76—Measuring, controlling or regulating
  • B29C45/82—Hydraulic or pneumatic circuits
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B22—CASTING; POWDER METALLURGY
  • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
  • B22D17/00—Pressure die casting or injection die casting, i.e. casting in which the metal is forced into a mould under high pressure
  • B22D17/20—Accessories: Details
  • B22D17/32—Controlling equipment
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C45/00—Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor
  • B29C45/17—Component parts, details or accessories; Auxiliary operations
  • B29C45/46—Means for plasticising or homogenising the moulding material or forcing it into the mould
  • B29C45/47—Means for plasticising or homogenising the moulding material or forcing it into the mould using screws
  • B29C45/50—Axially movable screw
  • B29C45/5008—Drive means therefor

Definitions

• the invention relates to an arrangement for a die casting machine according to the preamble of claim 1. Furthermore, the invention relates to a method for operating a drive piston in a working cylinder of a die casting machine.
• An arrangement according to the invention for a die-casting machine has a drive piston accommodated in a working cylinder and a pressure displacer upstream of the working cylinder.
• a piston chamber and on the other side of the drive piston an annular space in the working cylinder is arranged.
• a connecting line is the annular space of the working cylinder with the piston chamber of the working cylinder connectable.
• this connection can be made directly or via a check valve.
• the check valve can be arranged integrated in the pressure interrupter or bridged the pressure interrupter.
• connection line To the said connection line may be connected a pressure medium source.
• a pressure medium can be fed into the hydraulic circuit in a simple manner.
• the pressure medium source can be a pump or an accumulator.
• connection line has a hydraulic valve with which the connecting line to the annular space of the pressure translator can be separated.
• a switchable hydraulic valve arranged in the connection line makes it possible to use the same connection line also for a connection of the annular space of the working cylinder to the piston space of the working cylinder.
• the resulting differential circuit allows significant energy savings during slow movements of the working piston.
• a control valve is used instead of a simple switching valve.
• a switching valve may be provided in the combustion line to the piston chamber of the working cylinder and / or to the piston chamber of the pressure translator.
• the differential circuit consists essentially of a return of the outflowing pressure medium from the annular space of the working cylinder into the piston chamber of the working cylinder. This feedback can be done directly in the piston chamber of the working cylinder or via the check valve of the Druckschreibsetzers m the piston chamber of the working cylinder.
• the arrangement may have at least one hydraulic valve with variable opening, with the aid of which the ancestor speed of the drive piston can be influenced.
• a switching valve may be arranged, with which the Verbmdungs effet is hydraulically connected to a tank or separable as needed.
• a switching valve may be provided, with which the connecting line to the pressure medium source is connectable.
• a hydraulic valve with variable opening is seconded, which the Presence speed of the drive piston influenced.
• This valve can be used as a 4/3-way valve.
• a proportional pressure influence between the pressure medium source and the connecting line allows to influence the ring-like impression as well as the drive piston as well as the pressure booster in an optimal way.
• the arrangement may comprise two hydraulic valves which together form a hydraulic pressure divider in the connecting line.
• the two hydraulic valves of the pressure divider can be formed by two of the three aforementioned hydraulic valves.
• the hydraulic pressure divider is formed by the switchable hydraulic valve, with which the connecting line to the tank is hydraulically connectable and by the switchable hydraulic valve, through which the connecting line to the pressure medium source is connectable formed.
• at least one of the valves is designed as a valve with variable opening, wherein the variation of the opening via control signals and / or can be done with a direct Druckruckbowung.
• a Druckgiessinaschme may have alone or m combination with a vorgangig mentioned embodiment, a working cylinder and a cylinder upstream of the pressure translator.
• a drive piston is received, wherein on one side of the drive piston, a piston chamber and on the other side of the drive piston, an annular space in the working cylinder is arranged.
• a pressure divider can be formed such that a variable pressure is applied to the connection. can be fed supply line between the annulus and piston chamber of the working cylinder.
• Em further aspect of the invention relates to a method for operating the drive piston in a working cylinder for an injection unit of a die casting machine.
• the arrangement described above can be used for this method.
• the method is characterized in that when accelerating the drive piston when starting in a first step, the required for the stroke of the drive piston hydraulic medium is obtained from a pressure medium source. A continuous start-up or a gentle acceleration can thus be achieved. If, in a second step, the hydraulic medium is obtained from an accumulator, a further acceleration can be achieved without the known pressure peaks occurring. The acceleration of the drive piston is thus easily controlled.
• the advance speed of the drive piston can be influenced by at least one variable-opening hydraulic valve when the hydraulic valve is arranged in an annular conduit from an annular space to a piston space of the working cylinder.
• a base volume flow can be influenced by the pressure medium source via the connecting line to the tank and / or a resulting pressure in the connecting line of the pressure divider.
• the quality and above all the dynamics of the pressure influencing m of the connecting line is thereby substantially increased.
• Another aspect of the invention relates to a method for operating the drive piston in a working cylinder for an injection unit of a die casting machine.
• the arrangement described above can be used for this method.
• the method is characterized in that in a predetermined phase, one side of the drive piston, a pressure medium from a pressure medium source for generating a pressure is supplied and at the same time to generate an opposing counterpressure on the drive piston pressure medium is also guided to the other side of the drive piston, whereby the drive piston is clamped between two oppositely acting forces. Via the connection line connecting the two sides, i.
• Figure 1 a erfmdungsgemasse arrangement based on a modification of an embodiment according to DE 198 42 38
• Figure 2 a further embodiment of an arrangement
• Figure 3 an alternative arrangement.
• Figure 1 shows a generally designated 1 arrangement for a die casting machine with a in a working cylinder 2 and a working cylinder 2 upstream Druckuberseter 8.
• the representation according to Figure 1 is based on Fig. 2 from DE 198 42 38 Al, with the main difference that a connecting line 10 'is arranged between the connecting lines designated 10 and 12. Tests have surprisingly shown that such a switching arrangement offers many possibilities for optimization.
• a casting piston 11 of a die casting machine connected to a displacement measuring system 2 is driven via a piston rod by a drive piston 3, which is displaceably arranged in a working cylinder 2.
• the movement of the working cylinder is preferably controlled by means of a continuous valve 14 connected to a discharge line (discharge during the injection cycle) or by means of which its magnet is fed, as is known per se and therefore will not be described in detail here.
• the aforementioned valve 14 can also take over the setting of the pressure in the annular space 5 of the working cylinder 2.
• two lines are provided, of which one line leads directly to a pressure medium tank T, whereas the other line is connected to a pump P.
• Both the annulus 4 and the piston chamber 5 are pressure-electrical converter connected.
• the pressure interrupter 8 containing a pressure interrupter piston can be switched on to increase the pressure.
• the pressure booster piston has a piston part of larger diameter and a subsequent piston part of smaller diameter, each because they are displaceable in cylinder sections.
• the pressure booster piston 8 is connected in series with an accumulator 9, which can be opened or shut off via a check valve 19, controlled by the signal of at least one of the mentioned pressure-electric transmitters.
• the pressure built up in the annular space 5 via a line 10 for influencing the Druckubersetzerkolbens the Druckuberseters 8 are ruckgeschreibt. Expediently, this is done so that the line 10 connects the annular space 5 with that side (annular space 7) of the Druckubersetzerkolbens, at which adjoins the smaller piston part.
• the line 10 may be a simple line without cost-intensive installations.
• a hydraulic valve 16 may also be installed in the line 10. Via the line 10 there is automatically also a pressure regulation of the pressure booster by the pressure-regulating proportional valve 14, which thus fulfills two functions at the same time.
• FIG. 2 shows an arrangement 1 with approximately the same main components as in the first exemplary embodiment: an accumulator 9, a pressure interrupter 8 and a drive cylinder 2.
• the hydraulic circuit on the other hand, was modified.
• the switchable hydraulic connection of the connecting line with the piston chamber 4 of the working cylinder 2 explained in detail below makes it possible to operate the drive piston 3 in a differential circuit in a particularly simple manner, which leads to a considerable energy saving during relatively slow piston movements.
• a pressure medium source for example a pump, indicated by P.
• the arrangement 1 has in the Verbmdungs effet 10 a plurality of switchable hydraulic valves. With the switching valve 16, the connecting line 10 from the annular space 7 of the Druckuberset- 8 is separable. With the arranged in the line section 10 'switching valve 17, the Verbmdungs effet 10 from the piston chamber 4 of the drive piston is separable. With the switching valve 15, the connecting line 10 with a tank T is hydraulically connected. With the switching valve 18, the pressure medium source P is separable from the Verbmdungs effet.
• the two hydraulic valves 15 and 18 together form a hydraulic pressure divider in the Verbmdungs effet 10, wherein at least one of the two hydraulic valves 15, 18 by a control-side or hydraulic feedback (not shown) of the pressure in the Verbmdungs effet 10 is influenced.
• the switching valves 15-18 by hydraulic valves with variable opening or continuous valves.
• the use of at least one continuous valve instead of the valves 15, 17 and 18 shown in Figure 2 allows both slow and fast movements of the drive piston 3 and the pressure in the annular space 5 of the working cylinder and in the annular space 7 of the pressure distributor 8 via the connecting line 10, 10 ' especially to influence requirements.
• hydraulic valves can be used with functional nominal size, which greatly improves their dynamic behavior.
• FIG. 3 shows a hydraulic circuit for an alternative arrangement.
• the connecting line 10 is not connected directly to the piston chamber 4 of the working cylinder 2, but the connecting line 10, 10 'is connected to the piston chamber 13 of the pressure translator 8.
• This arrangement is only useful if an effective on the pressure intensifier 8 check valve is present. With this arrangement, the differential pressure at the valve 17 can be significantly reduced, so that inexpensive, commercially available hydraulic valves can be used.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Manufacturing & Machinery (AREA)
• Fluid-Pressure Circuits (AREA)
• Injection Moulding Of Plastics Or The Like (AREA)
• Supply Devices, Intensifiers, Converters, And Telemotors (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=42077501

Family Applications (1)

Country Status (6)

Families Citing this family (12)

Family Cites Families (23)

• 2008
  • 2008-12-17 DE DE102008055536A patent/DE102008055536A1/de not_active Withdrawn
• 2009
  • 2009-12-17 US US13/140,185 patent/US20110247777A1/en not_active Abandoned
  • 2009-12-17 JP JP2011541445A patent/JP2012512032A/ja active Pending
  • 2009-12-17 WO PCT/EP2009/067424 patent/WO2010070053A1/de active Application Filing
  • 2009-12-17 CN CN2009801569407A patent/CN102317007A/zh active Pending
  • 2009-12-17 EP EP09795978A patent/EP2384249A1/de not_active Withdrawn

Non-Patent Citations (1)

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