Clamping unit for a molding machine and method for operating

Abstract

Clamping unit for a molding machine, having: - a movable mold clamping plate (2), - a quick stroke device (4) which constitutes a drive for a quick stroke movement of the movable mold clamping plate (2) relative to a stationary mold clamping plate (3), - at least one closing force mechanism (5) separate from the quick stroke device (4), which constitutes a means for exerting a closing force on the movable mold clamping plate (2) by means of at least one hydraulic closing force cylinder (6), and - at least one hydraulic pump (14) together with a pump motor (50).

Description

Technical Field

[0001] This disclosure relates to a mold clamping unit having the features of the preamble of claim 1 for a molding machine, particularly an injection molding machine, a molding machine having such a mold clamping unit, and a method for operating the mold clamping unit. Background Technology

[0002] Molding machines can be understood as injection molding machines, pressure injection machines, and presses. Among them, a molding machine that transports the plasticized molding material to the opened mold is also entirely conceivable.

[0003] The following is an overview of existing technology based on injection molding machines. Similar situations generally apply to molding machines.

[0004] This clamping unit for injection molding machines includes

[0005] - Movable mold clamping plate,

[0006] - A rapid stroke device configured to drive a movable mold clamping plate to perform a rapid stroke movement relative to a fixed mold clamping plate.

[0007] - At least one closing force mechanism separate from the rapid stroke device, the closing force mechanism being configured to apply a closing force to a movable mold clamping plate by means of at least one hydraulic closing force cylinder.

[0008] - At least one hydraulic pump along with its motor,

[0009] The rapid stroke device is connected to the frame of a movable mold clamping plate or mold closing unit via at least one hydraulic piston cylinder unit having a pressure chamber, and the pressure chamber of at least one hydraulic piston cylinder unit is fluidly connected to or can be fluidly connected to at least one hydraulic closing force cylinder, such that...

[0010] - The first movement of the rapid-stroke device causes a rapid-stroke movement, in which the pressure chamber of at least one hydraulic piston cylinder unit is locked, and

[0011] - The second movement of the rapid stroke device causes the generation of a closing force via a pressure chamber fluidly connected to at least one hydraulic closing force cylinder, wherein the pressure chamber of at least one hydraulic piston cylinder unit is unlocked.

[0012] The implementation scheme of the mold closing unit having a fast stroke device coupled with a unit for generating closing force is known in principle from the structure of a two-plate mold closing unit guided by a tie rod, for example from AT 9995 U1.

[0013] In embodiments where closing force loading is performed via a rapidly moving element coupled to the closing force cylinder, high closing forces can be achieved within a very small construction space using a relatively simple mechanism. Conversely, it is a common view among those skilled in the art that this must be accepted in terms of energy efficiency. For example, in embodiments from AT 9995 U1, certain precautions must be taken to ensure that the closing force cylinder can be unloaded reliably and without damaging the hydraulic system and the rapidly moving device. Summary of the Invention

[0014] The purpose of this disclosure is to provide a clamping unit for a molding machine and a method for operating the clamping unit, by means of which the clamping unit can at least partially improve the disadvantages of the prior art, and / or by means of which the clamping unit can perform more energy-efficient production, and / or the clamping unit has a more compact drive design, and / or by means of which the clamping unit can reduce oil volume, and / or by means of which the clamping unit can shorten cycle time.

[0015] Within the scope of this disclosure, the objective is achieved by means of a mold clamping unit for a molding machine having the features of claim 1, a molding machine having such a mold clamping unit, and a method for operating the mold clamping unit for a molding machine having the features of claim 15.

[0016] According to one embodiment of this disclosure, a mold clamping unit for a molding machine, particularly an injection molding machine, has the following components:

[0017] - Movable mold clamping plate,

[0018] - A rapid stroke device configured to drive a movable mold clamping plate to perform a rapid stroke movement relative to a fixed mold clamping plate.

[0019] - At least one closing force mechanism separate from the rapid-stroke device, the closing force mechanism being configured to apply a closing force to a movable mold clamping plate by means of at least one hydraulic closing force cylinder, and

[0020] - At least one hydraulic pump along with its motor,

[0021] The rapid stroke device is connected to the frame of a movable mold clamping plate or mold closing unit via at least one hydraulic piston cylinder unit having a pressure chamber, and the pressure chamber of at least one hydraulic piston cylinder unit is fluidly connected to or can be fluidly connected to at least one hydraulic closing force cylinder, such that...

[0022] - The first movement of the rapid-stroke device causes a rapid-stroke movement, in which the pressure chamber of at least one hydraulic piston cylinder unit is locked, and

[0023] - The second movement of the rapid-stroke device generates a closing force via a pressure chamber fluidly connected to a hydraulic closing force cylinder, wherein the pressure chamber of at least one hydraulic piston cylinder unit is unlocked.

[0024] At least one hydraulic pump is fluidly connected to or may be fluidly connected to at least one hydraulic closing force cylinder, and the at least one hydraulic pump together with a pump motor is configured to at least partially recover the energy present under the closing force in the hydraulic medium in the at least one closing force cylinder by means of generator operation when the closing force is reduced.

[0025] By coupling the rapid stroke device with a hydraulic piston cylinder unit, the rapid stroke device can be used for dual purposes. On the one hand, the rapid stroke device can be used for the rapid stroke movement of a movable mold clamping plate, and on the other hand, it can be used as a drive unit for a closing force cylinder to generate closing force.

[0026] Therefore, the dynamic and rapid movement of the rapid stroke device can also realize dynamic and rapid drive motion to generate closing force, thereby not only meeting the dynamic and individualized requirements for the generation of closing force, but also generating closing force more quickly, thereby reducing the cycle time in the production process of the molding machine.

[0027] Furthermore, the drive unit of the mold clamping unit can be designed more compactly to meet its space requirements.

[0028] Furthermore, combining the closing force cylinder with a rapid stroke device can significantly reduce the oil volume of the hydraulic unit, as it saves the need for a separately connected and mostly large-sized drive unit for the closing force cylinder.

[0029] Furthermore, the feasibility of operating more energy-efficiently is demonstrated because, for example, the braking energy loss (which has existed since then when the movable mold clamping plate approaches the fixed mold clamping plate during the closing motion) can now be directly introduced into at least one piston cylinder unit, so that the braking energy can be used to generate pressure in the closing force cylinder at least in part.

[0030] It has been quite surprising that the system can also be designed with greater energy efficiency in terms of reducing closing force. As mentioned, this was initially understood to be a disadvantage of mold-closing units with rapid-stroke devices coupled to the closing force cylinder.

[0031] Therefore, a particular advantage is given by the fact that at least one hydraulic pump is fluidly connected to or can be fluidly connected to at least one hydraulic closing force cylinder, and the at least one hydraulic pump together with the pump motor is configured to at least partially recover the energy present under the closing force in the hydraulic medium in the at least one closing force cylinder by means of generator operation when the closing force is reduced.

[0032] Therefore, by using at least one hydraulic pump along with a pump motor in generator-type operation, energy can be recovered into the system in a particularly efficient manner and method (e.g., as electrical energy recovery, which in turn is used to drive at least one hydraulic pump for pressure generation).

[0033] The hydraulic pump also performs the following functions: to safely and efficiently depressurize hydraulic media under very high stress and pressure, so that the hydraulic media can be discharged, for example, into a tank.

[0034] Preferably, the mold closing unit is configured as a tie rod-less mold closing unit, a two-plate mold closing unit, or a column-guided mold closing unit.

[0035] Molding machines can be understood as injection molding machines, pressure injection machines, and presses. Among them, a molding machine that transports the plasticized molding material to the opened mold is also entirely conceivable.

[0036] Within the scope of this document—when referring to a “plate”—it does not necessarily mean a flat, planar plate. The plate may also have recesses, ridges, and concave or convex shapes on clamping surfaces for optimal force distribution in the closed state. Embodiments with ribs, tabs, especially connecting tabs with pressure pads, or other structures for stabilization or method optimization are also entirely conceivable.

[0037] It is also entirely conceivable that the mold-closing unit according to this disclosure can be provided not only by implementing a new mold-closing unit, but also by implementing a corresponding system at an existing mold-closing unit—as described in the introduction of the specification.

[0038] The features, measures, and advantages described in the prior art can also be implemented in conjunction with the remainder of this disclosure.

[0039] Preferably, the hydraulic medium can be hydraulic oil, wherein, as is known in the prior art, certain additives may be present.

[0040] Advantageous embodiments of this disclosure are defined in the dependent claims.

[0041] It can be proposed that at least one hydraulic switching valve is provided, wherein in a first switching position of the at least one hydraulic switching valve, the pressure chamber of the at least one hydraulic switching valve and the pressure chamber of at least one hydraulic piston cylinder unit are locked, and in a second switching position, the pressure chamber of at least one hydraulic piston cylinder unit is unlocked.

[0042] Preferably, an open-loop or closed-loop control device is provided, which is connected to at least one hydraulic switching valve via signal transmission. The open-loop or closed-loop control device is configured to operate at least one hydraulic switching valve between a first switching position and a second switching position.

[0043] It can be proposed that at least one piston cylinder unit, at least one hydraulic closing force cylinder, fluid connection, and preferably at least one switching valve constitute part of a semi-closed or closed hydraulic system.

[0044] In addition, the closed hydraulic system may have an accumulator, preferably a pneumatic accumulator, to compensate for volume fluctuations in the closed hydraulic system.

[0045] Preferably, it may be proposed to provide at least one additional switching valve, particularly preferably a switching valve connected to at least one open-loop control or closed-loop control device via signal transmission, the at least one additional switching valve having at least two switching positions, wherein the first switching position of the at least one additional switching valve is a locked position, and the second switching position of the at least one additional switching valve realizes a pressure reduction of at least one hydraulic closing force cylinder, thereby realizing a reduction of closing force via the additional switching valve, and at least partially realizing generator-type operation of at least one hydraulic pump together with pump motor.

[0046] Therefore, it can be proposed that, by providing at least one additional switching valve and a second switching position via at least one additional switching valve, the energy released during the reduction of the closing force is directed to the closing force or other components of the molding machine, wherein, for example, the energy can be delivered to a hydraulic accumulator, the energy can be recovered as electrical energy, or the energy can be used to realize the movement of hydraulic actuators such as ejectors, clamps, core pullers or other auxiliary movements.

[0047] Preferably, at least one hydraulic pump and / or at least one accumulator, preferably via an additional switching valve, is connected to at least one hydraulic piston cylinder unit and / or at least one hydraulic closing force cylinder, or may be connected to at least one hydraulic piston cylinder unit and / or at least one hydraulic closing force cylinder.

[0048] By providing at least one hydraulic pump and connecting the at least one hydraulic pump to a hydraulic piston cylinder unit or closing force cylinder via, for example, at least one additional switching valve, the closing force cylinder and / or at least one piston cylinder unit can be returned to the initial position. For this purpose, at least one hydraulic pump of a fairly small design is sufficient, since it is not necessary to achieve particularly significant pressure for the reset movement.

[0049] Preferably, at least one hydraulic pump and / or at least one accumulator are configured to move, preferably reset to, at least one hydraulic piston cylinder unit and / or hydraulic closing force cylinder to an initial position.

[0050] It may be proposed that at least one hydraulic pump and / or at least one hydraulic accumulator be fluidly connected to or may be fluidly connected to the locking device, the ejector actuator and / or the core-pulling actuator.

[0051] Preferably, the piston face of at least one piston cylinder unit, and preferably the sum of the piston faces of the piston cylinder units, is configured in a manner less than the piston face of at least one closing force cylinder.

[0052] It can be proposed that at least two, preferably exactly two, piston cylinder units are provided, and the at least two piston cylinder units are connected to the rapid stroke device via a rapid traverse yoke.

[0053] Preferably, at least two piston cylinder units are directly attached to a movable mold clamping plate on the other hand.

[0054] It can be proposed that the rapid stroke device has at least one screw drive.

[0055] Preferably, at least one screw drive of the rapid stroke device is attached to the frame of the rapid movement yoke or mold closing unit by means of a nut, especially a recirculating ball nut.

[0056] It can be proposed that at least one piston cylinder unit and / or closing force cylinder be configured as a synchronous cylinder or a differential cylinder.

[0057] Preferably, the closing force mechanism is configured by means of at least one hydraulic closing force cylinder to apply the closing force to a movable mold clamping plate via a central pressure bar.

[0058] Furthermore, a method for protecting a mold clamping unit used in a molding machine is claimed, wherein the following steps are included:

[0059] - A rapid-stroke device is operated to perform a first movement, wherein the pressure chamber of at least one hydraulic piston cylinder unit is locked, and the first movement causes a rapid-stroke movement of a movable mold clamping plate.

[0060] - A rapid-stroke device is operated to perform a second movement, wherein the pressure chamber of at least one hydraulic piston-cylinder unit is connected via a fluid connection to a hydraulic closing force cylinder, the second movement generating a closing force via a central pressure rod through the closing force cylinder, and

[0061] - To recover at least partially the energy present under closing force in the hydraulic medium in at least one closing force cylinder via generator-type operation of at least one hydraulic pump, the at least one hydraulic pump together with a pump motor being fluidly connected to or potentially fluidly connected to at least one hydraulic closing force cylinder.

[0062] It can be proposed that the first motion transitions into the second motion, preferably directly and / or continuously. Attached Figure Description

[0063] Further details and advantages are described below with reference to the embodiments shown in the accompanying drawings. The following figures illustrate further details:

[0064] Figure 1 The first embodiment of the mold-closing unit is shown in a perspective view, cut along the longitudinal axis.

[0065] Figure 2 Shown in top view Figure 1 Implementation examples,

[0066] Figure 3 Shown in Figure 2 The cross-sectional view AA shown in the figure,

[0067] Figure 4 Shown in Figure 2 The cross-sectional view BB shown in the figure is shown in the figure.

[0068] Figure 5 A second embodiment of the mold clamping unit is shown in cross-section.

[0069] Figure 6 Show Figures 1 to 4 Hydraulic diagrams of embodiments,

[0070] Figure 7 An example of a flushing logic device is shown. Detailed Implementation

[0071] Figures 1 to 4 A first embodiment of the mold clamping unit 1 is shown.

[0072] Here, Figure 1 The mold-closing unit 1 is shown in a three-dimensional view, wherein, for better illustration, the mold-closing unit 1 is cut in a vertical plane through the longitudinal axis 24 of the mold-closing unit 1.

[0073] Here, in Figure 2 The diagram shows a top view of the mold clamping unit 1, and... Figure 3 The text shows that it has the characteristics of... Figure 2 The side view of section AA shown in the figure. Figure 4 Show Figure 2 BB, a cross-sectional view.

[0074] The mold-closing unit 1 includes a two-piece frame 10, which has a left side wall and a right side wall 22.

[0075] The side walls 22 are connected to each other on one hand via a fixed mold clamping plate 2 and on the other hand via a screw-on support plate 23. Furthermore, it may be suggested that the mold clamping unit 1 includes a connecting piece that can connect the two side walls 22.

[0076] The mold clamping unit 1 has a fixed mold clamping plate 3 and a movable mold clamping plate 2 that is movably supported relative to the fixed mold clamping plate 3 along the longitudinal axis 24.

[0077] The movable mold clamping plate 2 is supported at the frame 10 via the sliding guide 25 – more precisely: supported at the side wall 22 of the frame 10 – and can move along the longitudinal axis 24 by means of the rapid travel device 4 via the drive plate 26 and the transmission body 27.

[0078] The rapid travel device 4 includes an electric drive unit 28, which is configured to drive the screw 20 of the screw drive device 19 via a transmission device 29, thereby allowing the screw nut 21 supported on the screw 20 to move linearly.

[0079] The screw nut 21 is rigidly connected to the rapid-moving yoke 18 via a screwing part, and the rapid-moving yoke 18 transmits linear motion to the drive plate 26 via two piston cylinder units 8.

[0080] The rapid travel device 4 can open and / or close the mold 30, which can be positioned between the movable mold clamping plate 2 and the fixed mold clamping plate 3.

[0081] After the corresponding mold 30 is closed by the rapid stroke device 4, the closing force can be applied to the mold 30 by means of the closing force mechanism 5.

[0082] For this purpose, the central pressure rod 7 connected to the drive plate 26 is connected to the piston 32 of the closing force cylinder 6 by closing the locking device 15.

[0083] In the embodiment described, the locking device 15 is implemented as a separate locking nut 31, which can be locked or unlocked by means of a locking actuator 33.

[0084] The piston 32 of the closing force cylinder 6 is supported in a corresponding empty portion of the support plate 23, which forms the cylinder of the closing force cylinder 6. Through the corresponding pressure generated by the hydraulic fluid between the support plate 23 and the piston 32, a force (so-called closing force) can be applied to the mold 30 disposed between the movable mold clamping plate 2 and the fixed mold clamping plate 3 via the central pressure rod 7, the drive plate 26, the transmission body 27 and the movable mold clamping plate 2.

[0085] Under very high closing forces, the frame 10 deforms—more precisely, the sidewalls 22 of the frame 10 deform—causing the C-shaped frame 10 to crack, thereby jeopardizing the plate parallelism of the movable mold clamping plate 2 relative to the fixed mold clamping plate 3.

[0086] However, in order to also provide the parallelism of the movable mold clamping plate 2 relative to the fixed mold clamping plate 3, the movable mold clamping plate 2 can be tilted via the transmission body 27.

[0087] The fixed mold clamping plate 3 is directly supported at the frame 10.

[0088] Figure 5 A second embodiment of the mold clamping unit 1 is shown, wherein the electric drive unit 28 of the rapid stroke device 4, together with the transmission device 29 and the screw 20 of the screw drive device 19, is linearly movable relative to the frame 10.

[0089] The linear mobility is achieved via the linear guide 49.

[0090] A piston cylinder unit 8 is provided between the linearly guided component (composed of an electric drive unit 28, a transmission device 29, and a screw 20) and the frame 10.

[0091] Figure 5 The remaining features of the embodiments are substantially corresponding to Figures 1 to 4 Features of the first embodiment.

[0092] Figure 6 Show Figures 1 to 4 The hydraulic diagrams of the embodiments are provided, through which the hydraulic relationships of the various actuators will be explained in detail below.

[0093] Therefore, the piston cylinder unit 8 together with its pressure chamber 9 can be seen in the lower part of the hydraulic diagram.

[0094] Schematic, in the Figure 5 As shown in the diagram, piston cylinder unit 8—more precisely, piston 9 of piston cylinder unit 8—is mechanically connected to screw drive device 19 driven by electric drive unit 28 via rapid-moving yoke 18.

[0095] Furthermore, the cylinder of piston cylinder unit 8 is mechanically coupled to drive plate 26, which in turn... Figure 6 The upper part is also effectively connected to the ejector actuator 16 and the locking device 15 (this should be indicated by the dashed lines).

[0096] The pressure chambers 9 of the piston cylinder unit 8 are connected to each other and are implemented as differential cylinders in the specific embodiment.

[0097] The pressure chamber 9 of the hydraulic piston cylinder unit 8 is fluidly connected to the closing force cylinder 6 via hydraulic line 34.

[0098] The hydraulic fluid connection between the closing force cylinder 6 and the piston cylinder unit 8 via the hydraulic line 34 can be connected or disconnected by means of the switching valve 11.

[0099] In addition, there is a switching valve 40 in the hydraulic line 34, the function of which is described in detail below.

[0100] In order to draw hydraulic fluid from the closing force cylinder 6 back to the piston cylinder unit 8 during the generation of the closing force, a second hydraulic line 35 is provided, which can be locked by switching valves 36 and 42.

[0101] If the mold clamping unit 1 is closed now, the rapid stroke device 4 moves so that the movable mold clamping plate 2 approaches the fixed mold clamping plate 3 during the first movement.

[0102] The first movement continues until the movable mold clamping plate 2 is abutted against the fixed mold clamping plate 3 via the mold 30.

[0103] During the first movement of the rapid stroke device 4, switching valves 11, 36, 40 and 41 remain closed, thereby locking the piston cylinder unit 8 and preventing the piston cylinder unit 8 from moving.

[0104] Once the movable mold clamping plate 2 is attached to the fixed mold clamping plate 3 via the mold 30, valves 11, 36, 40 and 41 are opened, thereby connecting the pressure chamber 9 to the closing force cylinder 6 via the first hydraulic line 34.

[0105] Switching valves 12 and 42 remain in the locked position during this period.

[0106] With switching valves 11, 36, 40 and 41 open, the rapid stroke device 4 now performs a second motion, thereby moving the piston in the piston cylinder unit 8 and supplying hydraulic fluid from the pressure chamber 9 via the hydraulic line 34 to the closing force cylinder 6.

[0107] By delivering hydraulic fluid from the pressure chamber 9 through the hydraulic line 34 to the closing force cylinder 6, a closing force is now generated between the movable mold clamping plate 2 and the fixed mold clamping plate 3.

[0108] During the first and second movements of the rapid-stroke device 4, the additional valve 12 remains in the shown locked position. The switching valve 37 also remains in the shown closed switching position during the first and second movements of the rapid-stroke device 4.

[0109] The pressure or volume difference of the hydraulic fluid that may occur between hydraulic lines 34 and 35 can be compensated by check valve 38 and accumulator 39.

[0110] After the injection process of plasticizing the molding material into the mold 30 is performed, and after the holding pressure stage or cooling stage, the closing force can be reduced again.

[0111] To reduce the closing force, switch valves 11, 36, 40 and 41 are closed and switch valves 12 and 37 are opened.

[0112] To be precise, here, when reducing the closing force, the other switching valve 12 is placed in the switching position on the right.

[0113] By switching the right side of the additional switching valve 12, the pressure released from the closing force cylinder 6 can be used for auxiliary movement of the mold closing unit 1, such as operating the ejection unit via the ejection actuator 16, operating the core pulling actuator 17, or also for locking the actuator 33.

[0114] For example, the ejector actuator 16, the core-pulling actuator 17, or the locking actuator 33 can be manipulated, controlled in an open-loop or closed-loop manner by means of switching valves 43, 44, and 45.

[0115] Furthermore, excess pressure from the closing force reduction process is recovered as electrical energy again via hydraulic pump 14 and pump motor 50 connected to said hydraulic pump, which can be used in generator-type operation.

[0116] After reducing the closing force, switch valves 12 and 37 are switched again, with the other valve 12 moved to the switching position on the left and switch valve 37 placed in the locked position.

[0117] Through the connection, the closing force cylinder 6 can then be returned to its initial position via the hydraulic pump 14.

[0118] During this period, the rapid travel device 4 can also move back in parallel, and switching valves 11, 36 and 42 can be opened, while valves 40 and 36 remain closed.

[0119] By opening the switching valves 11, 36 and 42, the piston cylinder unit 8 can also be returned to its initial position by means of the rapid stroke device 4.

[0120] In addition, a flushing logic device 46 may be provided, wherein the flushing logic device is... Figure 6 It is shown only schematically.

[0121] The flushing logic device 46 can, for example, be based on... Figure 7 accomplish.

[0122] exist Figure 7 The flushing logic device 46 shown includes a switching valve 47, which can selectively connect one of the two hydraulic lines 34, 35 to the tank via a pressure relief valve 47, so as to flush the corresponding hydraulic line 34, 35.

[0123] Therefore, these two hydraulic lines 34 and 35 are locked in the switching valve 47 (as stated in the...). Figure 7 (As shown in the diagram) in the middle position.

[0124] Therefore, hydraulic line 34 can be flushed in the right position of switching valve 47 and hydraulic line 35 can be flushed in the left position of switching valve 47.

[0125] List of reference numerals

[0126] 1 mold closing unit

[0127] 2 Movable mold clamping plate

[0128] 3. Fixed mold clamping plate

[0129] 4. Rapid travel equipment

[0130] 5. Closed-loop mechanism

[0131] 6-closed force cylinder

[0132] 7. Central pressure bar

[0133] 8-piston cylinder unit

[0134] 9 pressure chambers

[0135] 10 frames

[0136] 11 Switching valve

[0137] 12. Other switching valves

[0138] 13 Open-loop or closed-loop control equipment

[0139] 14 Hydraulic pumps

[0140] 15 Locking Devices

[0141] 16 ejector actuators

[0142] 17-core pull actuator

[0143] 18 Fast yoke

[0144] 19-screw drive unit

[0145] 20 screw

[0146] 21 screw nut

[0147] 22 sidewalls

[0148] 23 bearing plate

[0149] 24 longitudinal axis

[0150] 25 Sliding Guide Section

[0151] 26 driver boards

[0152] 27 Transmitters

[0153] 28 electric drive units

[0154] 29 Transmission Device

[0155] 30 molds

[0156] 31 Locking Nut

[0157] 32 pistons

[0158] 33 Locking Actuator

[0159] 34 Hydraulic lines

[0160] 35 hydraulic lines

[0161] 36 switching valve

[0162] 37 Switching Valve

[0163] 38 Check Valve

[0164] 39 Accumulator

[0165] 40 switching valve

[0166] 41 Switching Valve

[0167] 42 Switching Valve

[0168] 43 Switching valve

[0169] 44 Switching Valve

[0170] 45 Switching Valve

[0171] 46 Flushing Logic Device

[0172] 47 Switching Valve

[0173] 48 pressure relief valve

[0174] 49 Linear Guide Section

[0175] 50 pump motor

Claims

1. A mold clamping unit for a molding machine, the mold clamping unit having - Movable mold clamping plate (2). - A rapid stroke device (4), which is configured to drive the movable mold clamping plate (2) to perform rapid stroke movement relative to the fixed mold clamping plate (3). - At least one closing force mechanism (5) separate from the rapid stroke device (4), the closing force mechanism being configured to apply a closing force to the movable mold clamping plate (2) by means of at least one hydraulic closing force cylinder (6), and - At least one hydraulic pump (14) together with pump motor (50). The rapid stroke device (4) is connected to the movable mold clamping plate (2) or the frame (10) of the mold clamping unit (1) via at least one hydraulic piston cylinder unit (8) having a pressure chamber (9), and the pressure chamber (9) of the at least one hydraulic piston cylinder unit (8) is fluidly connected to or can be fluidly connected to the at least one hydraulic closing force cylinder (6), such that... - The first movement of the rapid stroke device (4) causes the rapid stroke movement, wherein the pressure chamber (9) of the at least one hydraulic piston cylinder unit (8) is locked, and - The second movement of the rapid stroke device (4) causes the generation of a closing force via the pressure chamber (9) and the at least one hydraulic closing force cylinder (6), wherein the pressure chamber (9) of the at least one hydraulic piston cylinder unit (8) is unlocked. Its features are, The at least one hydraulic pump (14) is fluidly connected to or is capable of being fluidly connected to the at least one hydraulic closing force cylinder (6), and the at least one hydraulic pump (14) together with the pump motor (50) is configured to recover at least partially the energy present under the closing force in the hydraulic medium in the at least one closing force cylinder (6) by means of generator operation when the closing force is reduced.

2. The mold closing unit according to claim 1, wherein at least one hydraulic switching valve (11) is provided, the at least one hydraulic switching valve being configured such that in a first switching position of the at least one hydraulic switching valve (11), the pressure chamber (9) of the at least one hydraulic piston cylinder unit (8) is locked, and in a second switching position, the pressure chamber (9) of the at least one hydraulic piston cylinder unit (8) is unlocked.

3. The mold closing unit according to claim 2, wherein an open-loop control or closed-loop control device (13) is provided to be connected to the at least one hydraulic switching valve (11) in a signal transmission manner, the open-loop control or closed-loop control device being configured to operate the at least one hydraulic switching valve (11) between the first switching position and the second switching position.

4. The mold closing unit according to at least one of the preceding claims, wherein the at least one piston cylinder unit (8), the at least one hydraulic closing force cylinder (6), the fluid connection, and preferably at least one of the switching valves (12) constitute part of a semi-closed or closed hydraulic system.

5. A mold-closing unit according to at least one of the preceding claims, wherein at least one additional switching valve (12) is provided, preferably connected to at least one of the open-loop control or closed-loop control devices (13) in a signal transmission manner, the at least one additional switching valve having at least two switching positions, wherein the first switching position of the at least one additional switching valve (12) is a locked position, and the second switching position of the at least one additional switching valve (12) reduces the pressure of the at least one hydraulic closing force cylinder (6), thereby reducing the closing force via the additional switching valve (12), and at least partially realizing the generator-type operation of the at least one hydraulic pump (14) together with the pump motor (50).

6. The mold closing unit according to at least one of the preceding claims, wherein the at least one hydraulic pump (14) and / or at least one accumulator is preferably connected to or capable of being connected to the at least one hydraulic piston cylinder unit (8) and / or the at least one hydraulic closing force cylinder (6) via an additional switching valve (12).

7. The mold closing unit according to at least one of the preceding claims, wherein the at least one hydraulic pump (14) and / or the at least one accumulator are configured to move, preferably reset to, the at least one hydraulic piston cylinder unit (8) and / or the at least one hydraulic closing force cylinder (6) to an initial position.

8. The mold clamping unit according to at least one of the preceding claims, wherein the at least one hydraulic pump (14) and / or the at least one accumulator is fluidly connected to or is capable of being fluidly connected to the locking device (15), the ejector actuator (16), and / or the core-pulling actuator (17).

9. The mold closing unit according to at least one of the preceding claims, wherein the piston surface of the at least one piston cylinder unit (8), preferably the sum of the piston surfaces of the piston cylinder unit (8), is configured to be smaller than the piston surface of the at least one closing force cylinder (6).

10. The mold closing unit according to at least one of the preceding claims, wherein at least two, preferably exactly two, piston cylinder units (8) are provided, the at least two piston cylinder units (8) being connected to the rapid stroke device (4) via a rapid movement yoke (18).

11. The mold closing unit according to at least one of the preceding claims, wherein the rapid stroke device (4) has at least one screw drive (19).

12. The mold closing unit according to at least one of the preceding claims, wherein the at least one piston cylinder unit (8) is configured as a synchronous cylinder or a differential cylinder.

13. The mold clamping unit according to at least one of the preceding claims, wherein the closing force mechanism (5) is configured by means of the at least one hydraulic closing force cylinder (6) to apply the closing force to the movable mold clamping plate (2) via a central pressure rod (7).

14. A molding machine, particularly an injection molding machine, having a mold clamping unit (1) according to at least one of the preceding claims.

15. A method for operating a mold clamping unit (1) for a molding machine, preferably a mold clamping unit (1) according to any one of the preceding claims, The following steps are included: - The rapid stroke device (4) is manipulated to perform a first motion, wherein the pressure chamber (9) of at least one hydraulic piston cylinder unit (8) is locked, and the first motion causes a rapid stroke movement of the movable mold clamping plate (2). - Manipulating the rapid-stroke device (4) to perform a second movement, wherein the pressure chamber (9) of the at least one hydraulic piston cylinder unit (8) is connected via a fluid connection to at least one hydraulic closing force cylinder (6), the second movement causing the generation of a closing force through the at least one closing force cylinder (6), and - The energy present under the closing force in the hydraulic medium in the at least one closing force cylinder (6) is recovered at least partially by generator-type operation of at least one hydraulic pump (14), the at least one hydraulic pump (14) together with pump motor (50) being fluidly connected to or capable of being fluidly connected to the at least one hydraulic closing force cylinder (6).

16. The method of claim 15, wherein the transition from the first motion to the second motion is preferably direct and / or continuous.

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